====================
Release Changes List
====================
==============
version 1.10.0
==============
Thirteenth public release of Chapel, October 2, 2014
Highlights
----------
* changed Chapel's license and contributor agreement to Apache 2.0
(see 'Licensing Changes' section below)
* made Qthreads the default tasking layer for Chapel on most platforms
(see doc/README.chplenv and doc/README.tasks for details)
* added initial support for Intel Xeon Phi Knights Corner (KNC) processors
(see doc/platforms/README.knc)
* added new standard modules for bit operations, prefetch, file/directory utils
(see 'Standard Modules' section below)
* extended auxiliary file system support for HDFS to include Lustre and cURL
(see doc/README.auxIO for details)
* added support for set-based operations on associative domains and arrays
(see doc/technotes/README.sets and examples/primers/associative.chpl)
* added draft support for vector methods on 1D arrays with a personal domain
(see examples/primers/arrayVectorOps.chpl)
* added the ability to query arrays for the subdomain(s) that the locale owns
(see doc/technotes/README.subquery and examples/primers/distributions.chpl)
* added the ability to pass contiguous Chapel arrays to extern procedures
(see doc/technotes/README.extern)
* performance boosts due to Qthreads tasking, improved LICM, less communication
(see 'Performance Improvements' below)
* several generated code cleanups including C for loops and fewer ref temps
(see 'Generated Code Cleanups' below)
* significantly improved const-ness checking for fields, indices, domains/arrays
* fixed the semantics for passing sync/single variables to generic arguments
* improved support for, and orthogonality of, constructor calls
* added a compiler flag to support specializing for the target architecture
(see descriptions of CHPL_TARGET_ARCH and --[no-]specialize below)
* added symbolic CHPL_RT_NUM_THREADS_PER_LOCALE values to support common cases
(see doc/README.tasks for details)
* added an --about flag to Chapel executables to print compilation information
* new primer examples for associative domains/arrays, vector ops, random numbers
(see 'Example Codes' below)
* two new shootout benchmarks and many improvements to the existing ones
(see 'Example Codes' below)
* split setchplenv.* source scripts into "quick start" and "production" modes
(see $CHPL_HOME/README)
* by default, attempt to build and enable RE2 and GMP when possible
(see doc/README.chplenv)
* updated versions of hwloc, tcmalloc, and gasnet third-party packages
(see 'Third-Party Software Changes' below)
* numerous bug fixes
(see 'Bug Fixes' below)
* many test system improvements including C-based testing and external timers
(see 'Testing Sytem' and 'Performance Testing/Graphing System' below)
* many developer process improvements such as GitHub, Travis, Coverity, Jenkins
(see 'Developer-oriented Changes: Process Changes' below)
* many other developer-oriented improvements and refactorings
(see other 'Developer-oriented Changes: ...' sections below)
Licensing Changes
-----------------
* changed Chapel's license from BSD to Apache 2.0
(see $CHPL_HOME/LICENSE.chapel for details)
* changed Chapel's contributor agreement from a Cray agreement to Apache 2.0
(see http://chapel.cray.com/developers.html for details)
Packaging Changes
-----------------
* split the util/setchplenv.* scripts into quick-start and "production" versions
(see $CHPL_HOME/README and util/README for more information)
* for non-quickstart users, we now attempt to enable RE2 and GMP by default
(see doc/README.chplenv for details)
* removed the util/update-sources script which had fallen out-of-date
Environment Changes
-------------------
* changed the default value of CHPL_TASKS to 'qthreads' for most platforms
(see doc/README.chplenv and doc/README.tasks for details)
* added CHPL_TARGET_ARCH to describe the target processor architecture
(see doc/README.chplenv for details)
* added CHPL_AUX* environment variables for accessing HDFS, Lustre, and/or cURL
(see doc/technotes/README.auxIO)
* added symbolic physical/logical values for CHPL_RT_NUM_THREADS_PER_LOCALE
(see doc/README.tasks for details)
* generalized CHPL_RT_MAX_HEAP_SIZE to control GASNet's segment size
(see doc/README.executing for more information)
* generalized CHPL_RT_CALL_STACK_SIZE to control Qthread stack sizes
(see doc/README.executing for more information)
* renamed the CHPL_MEM setting previously called 'default' to 'cstdlib'
Portability Improvements
------------------------
* added initial support for Intel Xeon Phi Knights Corner (KNC) processors
(see doc/platforms/README.knc)
* fixed a bug in which newer versions of Cygwin weren't properly detected
Syntactic/Naming Changes
------------------------
* changed the syntax for task intents from 'ref(ident)' to 'with (ref ident)'
(see the 'Task Parallelism' chapter of the language specification for details)
* deprecated 'var functions' in favor of returning by 'ref' intent
(see the 'Procedures' chapter of the language specification for details)
* renamed the 'default' setting for CHPL_MEM to 'cstdlib'
(see doc/README.chplenv for details)
Semantic Changes / Changes to Chapel Language
---------------------------------------------
* made passing syncs/singles to generic arguments pass them by 'ref'
(previously, such calls would unwrap the sync/single, passing the value in)
* redefined op= on associative domains in terms of set operations
(see doc/technotes/README.sets for more information)
* made loops over ranges that rely on overflow undefined
(e.g., 'for i in 1..max(int) do ...' is not well-defined)
* make a more explicit distinction between the 'string' and 'c_string' types
(see doc/technotes/README.extern for more information on 'c_string')
* added support for the logical negation of integral types
(e.g., 'var x = 3; if (!x) then ...' is now legal Chapel code)
* removed support for interpreting {D} as D for domain D
(given 'const D: domain(...) = ...;', '{D}' is not a domain of domains)
New Features
------------
* added support for Lustre and cURL file systems
(see doc/technotes/README.auxIO and README.curl for details)
* added support for standard set operations on associative domains and arrays
(see doc/technotes/README.sets and examples/primers/associative.chpl)
* added support for extending an associative array's personal domain via stores
(see examples/primers/associative.chpl)
* added draft support for vector methods on 1D arrays with a personal domain
(see examples/primers/arrayVectorOps.chpl)
* added the ability to query arrays for the subdomain(s) that the locale owns
(see doc/technotes/README.subquery and examples/primers/distributions.chpl)
* made the compiler call user-defined default constructors when defined
* added the ability to call constructors through type aliases
(e.g., 'class C { ... } type t = C; var myT = new t();' now works)
* added support for numerous type-oriented queries for expressions
(see doc/technotes/README.typeQueries)
* added octal literals
(e.g., 0o777)
* added support for 'noinit' on record and class variables
(see the 'Variables' chapter of the language specification)
* added experimental support for user-defined default values for record types
(e.g., 'proc _defaultOf(type t) where t:R { var r: t; r = ...; return r; })
* added locale.maxTaskPar to query the # of parallel tasks a locale can support
(see the 'Locales' chapter of the language specification)
* added initial support for 'ref' variables using a placeholder 'refvar' syntax
(e.g., 'var x = 3; refvar y = x; x = 5; assert(y == 5);' will not fail)
Changes to the Implementation
-----------------------------
* improved the current support for HDFS file systems
(see doc/technotes/README.auxIO and README.hdfs for more information)
* made 'dataParTasksPerLocale' default to 'locale.maxTaskPar'
(see the 'Data Parallelism' chapter of the language specification)
New Interoperability Features
-----------------------------
* added the ability to pass contiguous Chapel arrays to extern procedures
(see README.extern)
* extern C procedures should now take 'c_string' arguments rather than 'string'
* changed the return type of is_c_nil from c_int to bool
Standard Modules
----------------
* added a new standard module supporting some initial bitwise operations
(see modules/standard/BitOps.chpl)
* added a new standard module supporting a prefetch() operation
(see modules/standard/Prefetch.chpl)
* added some initial file/directory utility routines (more planned for 1.11)
(e.g., remove(), rename(), cwd(), chdir(), mkdir(), chown())
* added draft support for glob() and walking directory trees
(see modules/standard/Filerator.chpl -- feedback desired)
* added readstring()/readline() methods that read bytes into strings/arrays
(see modules/standard/IO.chpl)
* added an experimental sorted() iterator for sorting arrays or other iterables
(see modules/standard/Sort.chpl)
* added the ability to have the Sort.chpl module routines sort in reverse
* implemented new module NewString defining 'string_rec'
(prototype to replace 'string' in version 1.11)
* added a printMemLeaks() routine for printing out a memory leaks table
(see modules/standard/Memory.chpl)
* improved Random.chpl's SeedGenerator.currentTime to avoid duplicate seeds
* rewrote the AdvancedIters module to use 'atomic' rather than 'sync' vars
* removed the Profiling-related modules and source code
Documentation
-------------
* added doc/platforms/README.knc to describe using Chapel for KNC
* added doc/technotes/README.auxIO and .curl to describe new file system support
* added doc/technotes/README.sets to describe new associative domain set ops
* added doc/technotes/README.fileUtil to describe current file utility routines
* added doc/technotes/README.subquery to describe array subdomain queries
* added a description of CHPL_RT_MAX_HEAP_SIZE/GASNET_MAX_SEGSIZE to README.cray
* improved the specification of procedure arguments and returns
* added the proposed support for forall intents to the language specification
* fixed a spec code example that failed to use task intents as needed
* many updates, clarifications, and improvements to the language specification
* many updates and improvements to the READMEs in general
Example Codes
-------------
* added a new primer for associative domains/arrays and set operations on them
(see examples/primers/associative.chpl)
* added a new primer for vector operations on 1D arrays
(see examples/primers/arrayVectorOps.chpl)
* added a new primer for random number generation
(see examples/primers/randomNumbers.chpl)
* added two new shootout benchmarks: meteor-fast, regexdna
(see examples/benchmarks/shootout/meteor-fast.chpl and regexdna.chpl)
* replaced the fannkuch-redux benchmark with a parallel version
(see examples/benchmarks/shootout/fannkuch-redux.chpl)
* updated the mandelbrot benchmark to use a dynamic iterator
(see examples/benchmarks/shootout/mandelbrot.chpl)
* updated chameneos benchmark to use conditionals instead of select statements
(see examples/benchmarks/shootout/chameneosredux.chpl)
* removed some CHPL_RT knob-fiddling from the thread-ring benchmark
* fixed the portability of the pidigits benchmark to 32-bit systems
(see examples/benchmarks/shootout/pidigits.chpl)
* updated the fileIO primer to utilize/demontrate whole-array I/O
(see examples/primers/fileIO.chpl)
* improved the locking strategy used in verification for the HPCC RA benchmark
* removed the unnecessary locking and error tolerance from ra-atomics.chpl
* changed HPCC RA benchmarks to print problem sizes before declaring arrays
* minor edits to the domains primer
Source Highlighting Changes (see etc/README)
--------------------------------------------
* updated vim, emacs, highlight, and source-highlight modes with new keywords
* other general improvements to vim and emacs modes
* added a pointer to the Chapel support for pygments
(see etc/pygments/README.rst)
Launcher-specific Notes
-----------------------
* improved the 'slurm-srun' launcher
* updated 'aprun' launcher to support KNC
* added environment forwarding for the 'amudprun' launcher
Compiler Flags (see 'man chpl' for details)
-------------------------------------------
* added a --[no-]specialize flag that supports CHPL_TARGET_ARCH specialization
(see doc/README.chplenv for details beyond those on the man page)
* added a --[no-]stack-checks flag to the compiler
(see README.tasks for details beyond those on the man page)
* made --fast imply --specialize and --no-stack-checks by default
* added a new --cache-remote flag to enable caching remote data
* --print-passes now prints additional timing information about passes
Flags on Generated Executables
------------------------------
* added an --about flag to print information about how a program was compiled
Error Message Improvements
--------------------------
* added an error message for function control paths that fail to return values
* added a warning if a hugepages module is/is not loaded as CHPL_COMM requires
* improved error messages for I/O failures
* improved the error message for assignments between unsupported type pairs
* improved resolution errors to distinguish between having 0 vs. 2+ candidates
* improved error messages for applying 'new' to incorrect expression types
* issue an error when using the --llvm flag when LLVM is not enabled
* fixed a warning message in which CHPL_GASNET_SEGMENT was mis-named
Performance Improvements
------------------------
* improved the performance of the Qthreads tasking layer
* improved the loop invariant code motion optimization for --no-local compiles
* improved the performance of the serial 1D array iterator
* optimized task counters to make use of network atomics when available
* reduced communication counts for several common code idioms
* added an experimental optimization for caching remote data with 'fifo' tasking
(see --cache-remote flag on 'chpl' man page)
* improved the performance of readstring()
Third-Party Software Changes
----------------------------
* made many improvements to our use of Qthreads in the 'qthreads' tasking layer
* updated snapshot of hwloc to version 1.9.1
* updated snapshot of tcmalloc to version 2.2 and patched to work with Chapel
* applied GASNet patches to fix pshm gemini/aries memory registration issues
* improved the portability of the re2 code base and regexp feature
* parallelized the build of the llvm and gmp packages to reduce build time
* reduced the number of llvm components we build to reduce build time
New Semantic Checks (for old semantics)
---------------------------------------
* improved const-ness checking for 'const' fields, loop indices, domains/arrays
* added checks for assignments to illegal l-values via op= operators
* added semantic checks to prevent against overflow in range iteration
Bug Fixes
---------
* fixed a bug in which int literals > max(int(32)) could not coerce to uint(32)
* fixed support for uppercase binary and hexidecimal literals
(e.g. 0B1101101 and 0Xbabe1055)
* fixed a bug in which ~1% of compiles would segfault on Macs
* fixed a bug relating to nested records and default constructors
* fixed a bug in which varargs functions with 'ref' intent did not work
* fixed a bug in which the compiler did not preserve param boolean sizes
* fixed a bug in 'noinit' initializations shared by multiple variables
* fixed a bug in which writef() was missing an overload
* fixed some bugs in readstring()
* fixed a race condition in associative domains' member() function
* fixed an internal error relating to record variables in param conditionals
* fixed some bugs in the GMP module
* fixed a bug in which multi-locale memory tracking was broken
* fixed a bug in loop-invariant code motion
* fixed several bugs in the LLVM backend
Runtime Library Changes
-----------------------
* refactored the runtime's auxiliary file system support to support many at once
* made the tasking layer specify the default value for dataParTasksPerLocale
* In 'qthreads' tasking, made the progress engine a pthread, not a task
* added new non-blocking communication functions to the runtime interface
* added yields to the communication layer's barriers to avoid wasting resources
* removed barrier-related communications from verbose comm output by default
Generated Code Cleanups
-----------------------
* changed the generated code to use C for-loops for ranges and certain arrays
* eliminated unnecessary reference temps in many common cases, like assignments
* added dead module elimination to reduce the amount of generated code
* removed extraneous chpl__readXX() calls from the generated code
* changed the mix of which compiler-generated functions are inlined vs. not
Compiler Performance
--------------------
* improved compilation speed by rewriting printchplenv and chplenv/* in Python
* consolidated the compiler's system calls to reduce compiler overhead
Testing System
--------------
* added the ability to add C-based tests to the test system
* added the ability for an *execopts file to redirect stdin as its last args
* added automatic squashing of internal module line numbers for .bad diffs
* the test system now logs a list of top CPU consumers if a test times out
* added a notion of a temporary test directory that is cleaned up after a run
* changed memory leaks test accounting to include strings
* added a --syspreexec flag to the start_test script
* added the ability to have locale-model-based .good files in testing
* added the ability to match against variants of an explicitly named .good file
Performance Testing/Graphing System
-----------------------------------
* add the ability to use different external timers in performance testing
* embedded the active graph list into the performance testing system's URLs
* removed duplicate checkboxes from the list of performance graphs
* fixed the support for annotating multiple graph series' at once
* made performance testing only run one trial for a higher-than-default timeout
* fixed a bug in which multiple performance test trials were replicating data
* made performance testing remove .exec.out.tmp on successful runs
* added the ability to graph .dat files listed by SVN revision rather than date
* made the default compiler performance directory unique by machine name
* avoided sync-ing performance graphs to the web if errors are encountered
* improved the behavior of the log-scale button's warning mode
Developer-oriented changes: Process Changes
-------------------------------------------
* migrated Chapel's repository from Subversion on SourceForge to git on github
* began using Travis for pre-commit sanity checks
* began using Coverity scan regularly to catch code quality issues
* converted testing from cron-based to Jenkins-based
* added a script to aid with building multiple Chapel configurations
(see util/build_configs.py --help for more information)
* added copyrights to sources within git (rather than tagging at release time)
Developer-oriented changes: Compiler Flags
------------------------------------------
* added a new --lldb developer flag for debugging with LLDB
* added a --print-module-resolution developer flag
* changed developer --version numbers to display the sha1 + branch
* made minor improvements to the --minimal-modules compilation mode
* removed the developer --ignore-internal-modules flag
Developer-oriented changes: Executable flags
--------------------------------------------
* added a -E flag for launchers to forward environment variables to _reals
Developer-oriented changes: Module improvements
-----------------------------------------------
* added an ability for developers to access 'param' and 'type' fields in Chapel
* merged internal ChapelRange and ChapelRangeBase modules/types together
* converted remaining assignment ops to use the new '=(ref x, y)' signature
* rewrote assignments to use PRIM_ASSIGN rather than PRIM_MOVE
* made ioerror return without exiting on ENOERR
* added a remote prefetch primitive
* extended network atomic interface to accept memory_order (currently ignored)
* fixed the return types of non-fetch network atomic methods to be 'void'
* refactored the reference counting code for domain maps, domains, and arrays
* converted internal use of external procedures to use 'c_string', not 'string'
* refactored Memory module to avoid injecting extern symbols into global scope
* refactored string support into new files
(see runtime/*/chpl-string.h/.c and modules/internal/String.chpl)
* moved privatized ID tracking from the runtime to the modules
* cleaned up deprecated file operations
Developer-oriented changes: Compiler improvements
-------------------------------------------------
* fixed a number of issues identified by Coverity and the Clang Static Analyzer
* created a "visitor" supporting a pre-order traversal of the IR
* rewrote the three viewing formats to use the new visitor capability
* added a PhaseTracker capability for taking timings within the compiler
* eliminated creation of order and coercion wrappers within compiler
* add memory fences to places that need them in the generated code and runtime
* added partial instantiation of generic functions to the resolution pass
* tightened up the use of function_exists() to avoid false matches
* significantly improved how default values are established by the compiler
* added an internal function for getting the first of an enum's values
* added a "ignore noinit" pragma to override noinit support
* squashed default initialization of certain compiler-introduced temp variables
* removed many compiler-introduced PRIM_MOVE operations
* improve how module uses are tracked and managed
* replaced the resolvedFns map with a flag on FnSymbols
* fixed the placement of an iterator tag argument
* removed some unnecessary scopeless block statements in the front-end
* replaced every procedure's nested BlockStmt with a single one
* moved module initialization function creation from parser to normalize
* various other code cleanups and refactorings
Developer-oriented changes: Compiler refactorings
-------------------------------------------------
* cleaned up the AST classes w.r.t. protected, private, const, etc.
* split statement AST nodes out from 'Expr' and into a new base class, 'Stmt'
* refactored view.cpp into three files matching its three viewing formats
(see compiler/AST/AstDump.cpp, ASTDumpToHTML.cpp, and view.cpp)
* refactored and cleaned up code related to specifying and running passes
* cleaned up the compiler's timer class
* cleaned up arg.cpp
* refactored logging related code into log.h/cpp
* moved insertWideReferences into its own file
* replaced Symbol class bool fields with flags
* removed dead code relating to garbage collection and the early interpreter
* removed dead FLAGs and memory descriptor types
Developer-oriented changes: Runtime improvements
------------------------------------------------
* refactored task-local runtime data into a single structure
* made the runtime code more resilient to mixing C++/C compilers
=============
version 1.9.0
=============
Twelfth public release of Chapel, April 17, 2014
Highlights (see entries in subsequent categories for details)
-------------------------------------------------------------
* numerous performance improvements (see 'Performance Improvements' below)
* significant reductions in compiler-introduced memory leaks
* added five new Computer Language Benchmark Games to the examples/ directory
* improved operator precedence for '|', '^', '&', '<<', '>>', '..', and 'in'
* added the ability for a user to create overloads of the assignment operator
* implemented atomic variables using intrinsics for Intel and Cray compilers
* flipped the default nested parallelism policy via dataParIgnoreRunningTasks
* significantly improved the stability/generality of the LLVM back-end
* added a slurm-srun launcher for use with native SLURM and improved pbs-aprun
* added a 'make check' rule to the top-level Makefile to validate a build
* improved the symmetry of program startup and polling across the locales
* significant improvements to the testing system, esp. performance testing
* updates to the GASNet and GMP packages and new snapshots of hwloc and re2
* improved the code base's portability w.r.t. clang, gcc, Mac OS X, Debian 7.4
* numerous bug fixes (see 'Bug Fixes' below)
Packaging Changes
-----------------
* added a 'make check' rule to the top-level Makefile to validate a build
* removed the half-hearted support for Chapel syntax highlighting in emacs 21
Environment Changes
-------------------
* added a new CHPL_HWLOC environment variable to control the use of 'hwloc'
(see doc/README.chplenv)
* made CHPL_*_COMPILER default to 'clang' for CHPL_*_PLATFORM 'darwin'
* made CHPL_TASKS default to 'qthreads' when CHPL_LOCALE_MODEL == 'numa'
* made CHPL_HWLOC default to 'hwloc' when CHPL_TASKS = 'qthreads'
* established a 1:1 correspondance between CHPL_TASKS and CHPL_THREADS options
* deprecated the user-controlled CHPL_THREADS environment variable
* removed support for CHPL_TASKS=none due to lack of significant utility
* made GASNet use the 'large' segment by default for the 'ibv' conduit
* made CHPL_LAUNCHER default to 'gasnetrun_ibv' when using GASNet's mxm conduit
(see doc/README.launcher)
Semantic Changes / Changes to Chapel Language
---------------------------------------------
* improved operator precedence for '|', '^', '&', '<<', '>>', '..', and 'in'
(see precedence tables in the 'Expressions' spec chapter or quick ref card)
* added the ability for a user to create overloads of the assignment operator
(see 'Statements' chapter in the language specification)
* added a 'noinit' capability to squash default initialization for basic types
(see 'Variables' chapter in the language specification)
* for a domain D, previously {D} == D; now it interprets it as 'domain(D.type)'
* added support for an expression-less 'serial' statement
(i.e., 'serial do' == 'serial true do')
* added support for dynamic casts of the 'nil' value, producing 'nil'
(see 'Conversions' chapter of the language specification)
* clarified that deleting a 'nil' value is OK and will have no effect
(see 'Classes' chapter of the language specification)
* added the ability to mark the 'this' as having 'ref' intent for methods
(see 'Classes' chapter of the language specification)
New Features
------------
* implemented support for the 'break' statement within param loops
Changes to the Implementation
-----------------------------
* dataParIgnoreRunningTasks is now 'false' by default for locale model 'flat'
(see doc/README.executing for details)
* changed the default size of the call stack size to 8 MiB for all task options
(see doc/README.tasks for details)
New Interoperability Features
-----------------------------
* extended c_ptrTo() to support 1D rectangular arrays
* added support for casts between c_ptr types
Standard Modules
----------------
* added support for abs() on imaginary types
* added isSubtype() and isProperSubtype() queries to the standard Types module
(see 'Standard Modules' chapter of the spec for details)
Documentation
-------------
* added descriptions of 'atomic' variables and 'noinit' expressions to the spec
(see the 'Task Parallelism and Synchronization' and 'Variables' sections)
* clarified specification of casting from numeric types to 'bool'
* reworked LICENSE files to clarify third-party licenses and isolate BSD text
(see LICENSE and LICENSE.chapel)
* refreshed and reorganized README.tasks
* documented that 'clang' is available as a CHPL_*_COMPILER option
(see doc/README.chplenv)
* improved description of Cray-specific runtime environment variables
(see doc/platforms/README.cray)
* clarified formatted I/O documentation regarding width/precision
(see doc/technotes/README.io)
* added a performance notes file (PERFORMANCE)
* removed the user agreement (AGREEMENT)
* generally refreshed README-based documentation
* general updates and improvements to the language specification
Example Codes
-------------
* added new Chapel ports of several Computer Language Benchmark Games (CLBG)
(see spectralnorm.chpl, mandelbrot.chpl, fannkuchredux.chpl, meteor.chpl,
and pidigits.chpl in benchmarks/shootout/)
* added an improved/simplified version of the CLBG chameneos-redux example
(see benchmarks/shootout/chameneosredux.chpl)
* improved the release versions of RA to use atomic rather than sync vars
* made the examples/programs/tree.chpl example reclaim its memory
* made minor improvements to the MiniMD example and primer examples
* fixed a few incorrect statements in comments within primers/syncsingle.chpl
Cray-specific Notes
-------------------
* changed Cray XC Systems(TM) to use GASNet over the aries conduit by default
* added a slurm-srun launcher for use with Cray systems supporting native SLURM
Launcher-specific Notes
-----------------------
* added a slurm-srun launcher for use with native SLURM systems
* improved the pbs-aprun launcher for use with Moab/Torque
* made the gasnetrun_ibv launcher forward all CHPL_ environment variables
* made the 'aprun' launcher more careful about when it can correctly use '-j'
Portability of code base
------------------------
* improved code base's portability to newer versions of gcc
* improved code base's portability to Darwin/Mac OS X and Debian 7.4
* improved code base's portability for compilation with 'clang'
* enabled 'tcmalloc' to be built on Cray XC systems
Compiler Flags (see 'man chpl' for details)
-------------------------------------------
* removed the --serial and --serial-forall flags; use serial statements instead
* started ignoring --static for Mac OS X since it isn't well-supported
* added a --print-passes-file flag to print passes to a specified filename
Error Message Improvements
--------------------------
* changed the wording of internal errors for succinctness
Performance Improvements
------------------------
* implemented atomic variables using intrinsics for Intel and Cray compilers
* optimized whole-array binary read/write operations for default domains/arrays
* extended global constant replication to additional types
* improved the compiler's ability to remote value forward values
* optimized away sublocale-related code for the 'flat' locale model
* improved 'numa' locale model performance for --local compilations)
* optimized blocking on sync variables for 'fifo' tasking based on # of tasks
* within serial sections, optimized forall loops over ranges, domains, arrays
* improved the task accounting for loops over Block-distributed arrays
* improved the loop-invariant code motion optimization's use of alias analysis
* removed unnecessary copies for formal arguments
* optimized program startup times in several ways
Locale Model Improvements
-------------------------
* improved the 'numa' locale model to reduce unnecessary changes in sublocale
* improved the 'numa' locale model's range, domain, and array iterators
Memory Improvements
-------------------
* reduced compiler-introduced memory leaks, particulary in I/O code
* reduced memory usage due to compiler-introduced copies on primitive types
* improved the reclamation of arrays of sync/single variables
* moved the end-of-program memory reporting to a point after the runtime exits
Third-Party Software Changes
----------------------------
* updated GASNet to version 1.22.0 with a patch to fix 'aries' conduit bugs
* added a snapshot of hwloc version 1.7.2 for compute node introspection
* added a snapshot of re2 (20140111) to the third-party directory
* added a snapshot of dygraphs to the third-party directory for perf graphs
* updated our snapshot of GMP to version 6.0.0
* various minor improvements to the Qthreads tasking layer
* disabled pshm for all non-udp GASNet conduits
Bug Fixes / New Semantic Checks (for old semantics)
---------------------------------------------------
* improved const-ness checking for const fields and const records/unions
* added a semantic check for tuple size mismatch when destructuring a tuple
* fixed a bug in which [u]int & imag literals were represented incorrectly
* fixed a bug where iterators with complex control flow could yield bad values
* fixed a bug in which timer.clear() did not reset the timer if it was running
* fixed a bug in which abs() on reals incorrectly called the complex version
* fixed a bug in converting between Chapel and C strings
* fixed a bug in which casts from ints/uints to bools were not always correct
* fixed some problems with the GMP random number routines
* fixed a bug on Cygwin for usernames with spaces in them
* extended global constant replication to additional types
* fixed a "read after freed" bug on domains used in nonblocking on calls
* fixed bug in loop invariant code motion related to aliasing in records/tuples
* fixed a subtle/minor race condition regarding accounting of tasks
* fixed Qthreads tasking layer bug resulting incorrect task placement
* fixed a bug in which Qthreads was asked for task-local storage prematurely
* fixed a potential race in task reporting (-t/--taskreport)
* fixed an optimization shortcut for array reindexing
* fixed a bug in which while loops warned about testing against local consts
* improved 'printchplenv' to avoid perl problems in unexpected cases
Runtime Library Changes
-----------------------
* improved the symmetry of program startup and polling across the locales
* improved descriptions of the runtime communication interface in chpl-comm.h
* simplified the implementation of the registry of global variables
* added ability for fifo tasks to implement thread-level storage using __thread
Generated Code Cleanups
-----------------------
* simplified the implementation of operations on homogeneous tuples
* removed the passing of wide strings by ref by default
* squashed the code generation of an unused program initialization function
* squashed redundant calls to initialize the ChapelStandard module
* folded out tautological comparisons between uints and 0s (e.g., myuint >= 0)
Compiler Performance
--------------------
* short-circuited the beautify pass if --savec is not specified
* short-circuited some logic in the parallel pass for --local compiles
Compiler Improvements
---------------------
* significantly improved the stability/generality of the LLVM back-end
* re-implemented copy propagation to handle aliases better
* made de-nested functions use 'const' arguments in more cases
Testing System
--------------
* added the ability to run multiple trials of each test to the testing system
* added support for sweeping current performance tests across past releases
* added the ability to track compiler performance during testing
* added a regexp-based correctness check capability for performance tests
* changed performance testing to support --fast by default
* added a script to splice .dat files created by performance testing
* permit SLURM to control the node list for parallel testing
* replaced 'paratest.server's -duplex flag with -nodepara for oversubscription
* added a capability to add annotations to performance graphs
* made performance testing compile with --static by default
* in generating performance graphs, the previous directory is now removed
* added a capability for the performance graphs to be rsync'd to SourceForge
* added a logarithmic/linear toggle to the generated performance graphs
* added a capability for the 'nightly' script to svn commit performance data
* added additional print messages to 'nightly' to better describe progress
* added a -retaintree option to 'nightly' to use the existing writable tree
* added support for testing the '--fast' flag in the 'nightly' script
* worked on making the testing system less Cray-centric in its design
* made test scripts send mail to the sourceforge mailing lists by default
* added options for naming test suites, specifying recipients, etc.
* unified the naming and structure of the cron job testing scripts
* removed reliance on tcsh-specific features for improved csh portability
Makefile Changes
----------------
* made all builds update Makefile dependences, not just developer builds
* made Makefiles propagate CFLAGS/CXXFLAGS to third-party builds
Internal/Developer-oriented
---------------------------
* added dataPar* arguments to these() iterators for ranges/default rectangular
* made Block's leader iterator forward to DefaultRectangular
* made sure that arguments to exported functions are always local/narrow
* changed most assignment operator signatures to take the LHS by 'ref'
* added support for a "minimal modules" compilation mode for core language work
* added a developer flag --report-optimized-loop-iterators to track loop opts
* made internal errors appear as such in developer mode
* refactored the reference count code for domain maps, domains, and arrays
* switched to a symbolic initializer for locale IDs to improve flexibility
* refactored QIO and Regexp reference counting
* deprecated the internal InitPrivateGlobals module
* added config params to support program startup communication diagnostics
(see 'printInitVerboseComm' and 'printInitCommCounts')
* added a verification pass to ensure ref types for return types are available
* renamed NUM_KIND_FLOAT to NUM_KIND_REAL
* renamed 'Class'->'Aggregate' in the compiler sources when record|class|union
* switched to a bulk copy of flags when copying Symbol classes
* changed the representation of intents to support bitmasks
* moved the initialization of memory tracking from the modules to the runtime
* removed user-level memory leaks from example codes in the language spec
* created FLAG_COMPILER_GENERATED to separate functions/labels from FLAG_TEMP
* added PRIM_IS_ATOMIC_TYPE to query whether something is an atomic type
* added new primitives for querying whether a type is a tuple, sync, or single
* improved the internal use cases of 'printchplenv'
* removed redundant overloads of ==/!= for syserr and err_t
* improved the implementation when 'noRefCount' is true
* removed no-longer-necessary _ensure_reference_type() feature
* changed extern routines that take string arguments to take 'c_string' instead
* changed extern routines that take 'inout' arguments to 'ref' when appropriate
* numerous refactorings of the compiler code for clarity and/or effiency
=============
version 1.8.0
=============
Eleventh public release of Chapel, October 17, 2013
Highlights (see entries in subsequent categories for details)
-------------------------------------------------------------
- added initial support for user-defined locale models and a NUMA locale model
- added initial support for accessing HDFS file systems via files/channels
- improved tasking semantics w.r.t. references to variables from outer scopes
- added new example codes for MiniMD and the Computer Language Benchmark Game
- performance optimizations related to array base pointers, loop-invariant code
- removed a number of compiler-generated memory leaks
- added new types for interoperating with C: c_string, c_ptr(type), c_void_ptr
- improved support for small-int computations, ranges, domains, and arrays
- support for dygraph-based performance monitoring in the testing system
- updates to the GASNet, Qthreads, MassiveThreads, LLVM, and CLANG packages
- added a new 'cray-cs' platform to represent Cray Cluster Supercomputers
- made 'gemini' the default GASNet conduit for 'cray-xe' and 'cray-xk'
- added support for a SLURM + GASNet-over-Infiniband launcher
New Features
------------
- added initial support for specifying locale models ('hierarchical locales')
(see doc/technotes/README.localeModels)
- added support for a prototype NUMA locale model
(see doc/technotes/README.localeModels)
- added initial support for accessing HDFS file systems via files/channels
(see doc/technotes/README.hdfs)
- added new 'const in' and 'const ref' argument intents
(see the 'Argument Intents' section in the language specification)
- added built-in config params for all CHPL_* environment settings
Semantic Changes / Changes to Chapel Language
---------------------------------------------
- improved tasking semantics w.r.t. references to variables from outer scopes
(e.g., in 'var x=0; begin { ...x... }', 'x' is a const copy within the task)
(see 'Task Intents' section in the language specification)
- added 'ref' clauses to obtain the previous reference tasking semantics
(e.g., 'var x: int; begin ref(x) { ...x... }' causes '...x...' to refer to x)
(see 'Task Intents' section in the language specification)
- made blank intents for atomic variables get interpreted as 'ref'
(see the 'Argument Intents' section in the language specification)
- added support for ranges, domains/arrays with small-int index types
(e.g., 'range(int(8))' is now a supported type)
- added operator support for pairs of small int/uint types
(e.g., 'int(8) + int(8)' now generates an int(8) rather than int(32))
- added operator support for homogenous tuple/scalar pairs
(e.g., (1,2,3) + 1 => (2,3,4))
- extended the member() method on domains to support varargs as well as tuples
(e.g., 'var D = {1..n, 1..n};' supports 'D.member(i,j)' and 'D.member((i,j))')
- the compiler now only creates '==' operators for matching record types
- made 'bool' types prefer dispatching to 'int' args over smaller-int options
(e.g., foo(true) will prefer to dispatch to foo(x:int) over foo(x:int(8)))
New Interoperability Features
-----------------------------
- added support for 'c_ptr(type)' and 'c_void_ptr' to refer to local C pointers
(see doc/technotes/README.extern)
- added support for a 'c_string' type to refer to local C char* pointers
(see doc/technotes/README.extern)
Deprecated Features
-------------------
- removed experimental GPU work to prepare for a revised approach to GPU support
- removed the callStackSize() query from the locale type
- removed certain config consts to control runtime arguments
(see "Flags on Generated Executables" section below)
Standard Modules
----------------
- added a new 'UtilReplicatedVar.chpl' standard module for replicated variables
- new 'HDFSiterator' and 'RecordParser' modules to help with parsing HDFS files
Documentation
-------------
- added a new README to describe the new locale model concept and NUMA model
(see doc/technotes/README.localeModels)
- added a new README.hdfs file to describe HDFS file system access in Chapel
(see doc/technotes/README.hdfs)
- made significant improvements to the README.cray file
(see doc/platforms/README.cray)
- refreshed the 'chpl' man page, particularly the SYNOPSIS/ENVIRONMENT sections
- refreshed the Chapel Quick Reference document
- major updates to the 'Task Parallelism' section of the spec for task intents
- made minor updates to several chapters in the language specification
- updated README.chplenv to reflect new CHPL_* environment variables
- minor updates to various README files
Example Codes
-------------
- added an initial port of the Mantevo MiniMD miniapp to Chapel
(see examples/benchmarks/miniMD)
- added Chapel ports of four codes from the Computer Language Benchmark Game
(see examples/benchmarks/shootout)
- fixed a bug in the atomics.chpl primer example
- cleaned up the beer.chpl example
Cray-specific Notes
-------------------
- added a new 'cray-cs' platform to represent Cray Cluster Supercomputers (CS)
(see doc/platforms/README.cray for more information)
- made 'gasnet' the default CHPL_COMM setting for all Cray platforms
- made 'gemini' the default GASNet conduit for 'cray-xe' and 'cray-xk' platforms
(see doc/platforms/README.cray)
- added support for the GASNet 'aries' conduit for the 'cray-xc' platform
(see doc/platforms/README.cray)
- made 'aprun' the default launcher for 'cray-x*' systems when available
- removed support for the 'xmt', 'x1', and 'x2' platforms and related features
- generated warning messages on cray-x* systems when no PrgEnv is loaded
- removed -target=linux flag from cray-prgenv-* compiler options
Launcher-specific Notes
-----------------------
- added support for a SLURM + GASNet-over-Infiniband launcher
(see 'slurm-gasnetrun_ibv' in doc/README.launcher)
- made the aprun-based launchers use the system's default number of CPUs
- brought the pbs launchers up-to-date with the current NCCS wrapper of qsub
Portability of code base
------------------------
- worked around a PGI portability issue with C structs in the generated code
Compiler Flags (see 'man chpl' for details)
-------------------------------------------
- added --[no-]warn-const-loops to control warnings about loops over constants
- added --[no-]loop-invariant-code-motion to enable/disable that optimization
- added --[no-]llvm-wide-opt to enable/disable LLVM wide pointer optimizations
- added warnings to '--[no-]serial' indicating its likely deprecation
Flags on Generated Executables
------------------------------
- replaced flags that govern runtime behavior with environment variables:
callStackSize -> CHPL_RT_CALL_STACK_SIZE
commConcurrency -> CHPL_RT_COMM_CONCURRENCY
numHardwareThreads -> CHPL_RT_NUM_HARDWARE_THREADS
numThreadsPerLocale -> CHPL_RT_NUM_THREADS_PER_LOCALE
Error Message Improvements
--------------------------
- improved const checking for actuals passed to out/inout/const ref/ref intents
- improved error messages for programs with bad type resolution cycles
- added a warning for while loops over constants
- errors for assignments to non-lvalues no longer halt compilation immediately
Performance Improvements
------------------------
- improved performance of local arrays by storing a shifted base pointer
- added a loop-invariant code motion optimization
- passed more things by value ('this', array/domain/domain map wrappers)
- made some improvements to the bulk copy optimization
Memory Leak Improvements
------------------------
- reduced memory leaked by strings by sharing them more aggressively
- improved support for destroying more automatic variables as they leave scope
- fixed a memory leak relating to inlining of iterators
- plugged memory leaks related to file types
- freed temporary buffers used for formatted I/O on complex values
Bug Fixes / New Semantic Checks (for old semantics)
---------------------------------------------------
- fixed bugs in extern blocks containing #define's
- fixed a bug when reading string literals that began with whitespace
- fixed a bug in which whitespace was written to binary files for array output
- fixed bugs related to writef() for complex values
- fixed size mismatches in IO code for 32-bit linux systems
- fixed a bug in the compareExchange implementation for atomic reals
- fixed bugs in Regexp convenience functions and the naming of string.split()
- fixed some bugs in BigInt functions in the GMP module
- fixed a bug in which AdvancedIterators would serialize if #chunks < #tasks
- fixed a bug related to 'ref' intents and the fast segment for GASNet
- fixed a bug related to using --make on the chpl command line
- bug fix for lost updates to fields of 'this' in certain scenarios
- fixed dead code elimination for blocks that are their own sole in-arc
Third-Party Software Changes
----------------------------
- updated to GASNet version 1.20.2 which improves the Cray native conduits
- updated to Qthreads version 1.10 and turned on support for stack overflow
(see reference to QT_GUARD_PAGES in doc/README.tasks for more information)
- updated to MassiveThreads version 0.95 with support for task-private data
- updated the LLVM back-end to use version 3.3 and packaged it with the release
- packaged CLANG 3.3 with the release rather than requiring a separate download
Runtime Library Changes
-----------------------
- made several interface changes to support locale models/hierarchical locales
Generated Code Cleanups
-----------------------
- declared non-exported symbols 'static' in generated code
- added support for targeting 'op=' operators in the back-end
- removed chains of unnecessary autocopy/autodestroy calls
Compiler Performance
--------------------
- disabled compiler internal verification by default to improve compile time
LLVM Back-end Changes
---------------------
- added wide pointer support for the LLVM back-end via CHPL_WIDE_POINTERS
(see doc/technotes/README.llvm and doc/README.chplenv)
- added support for LLVM-based communication optimizations via --llvm-wide-opt
(see doc/technotes/README.llvm)
Testing System
--------------
- changed performance graphing to use dygraphs
- added support for filing .bad files against futures to track behavior changes
- added support for setting environment variables on a per-test/-directory basis
- added the ability to use an external 'time -p' command for performance tests
- added directory-level PERFCOMPOPTS/PERFEXECOPTS files
- added a timeout feature for performance testing (separate from correctness)
- fixed a bug in which spec tests weren't being generated correctly
- added the capability for the test directory to clean itself up more thoroughly
Makefile Changes
----------------
- changed the naming scheme for intermediate object file directories
- added a 'cleanall' target between 'clean' and 'clobber'
(see README.building)
- made the 'clean' and 'cleanall' targets preserve a working installation
- accelerated the Makefile framework, particularly for no-op re-builds
- made the Makefiles smarter about rebuilding the compiler when necessary
Internal/Developer-oriented
---------------------------
- added a new 'createTaskFunctions' pass that creates functions defining tasks
- added a new 'resolveIntents' pass which resolves 'blank' and 'const' intents
- added a per-pass consistency/verification framework
- added a --verify compiler flag for running optional verification steps
- added an --ignore-errors-for-pass compiler flag for developers
- added a compiler analysis to compute dominators
- fixed a bug in isDefAndOrUse() for op= primitives
- rearchitected the QIO framework to support multiple file systems
- refactored the memory interface to better separate checking/tracking concerns
- switched to using 'ref' intents rather than 'inout' for I/O routines
- added "atomic type" flag for identifying atomic types to the compiler
- added "donor" function concept, making the callee responsible for deletion
- added "runtime type init fn" pragma to clarify overloaded "has runtime type"
- fixed a bug in which 'begin's in internal modules broke compilation
- restructured iterators so that not all yields would share the same variable
- improved cases where filename/line numbers aren't set correctly
- continued transition toward STL collections within the compiler
- added new capabilities to the bit vector class
- removed several instances of strcpy()s in the compiler
- added a functional interface for invoking remote functions by ID
- restructured #includes to avoid reliance on compiler-specific search policies
- added new features for debugging the compiler
Changes In Support of Hierarchical Locales
------------------------------------------
- made ranges and default rectangular domains/arrays use sublocales, if present
- made on-clauses get invoked through locale model module code in Chapel
- moved optimization of local on-clauses from the compiler to locale model code
- made task invocation flow through locale model module code written in Chapel
- mapped the tasking interface's support for hierarchical locales to Qthreads
- made hierarchical locale model compilations use wide pointers and on-clauses
=============
version 1.7.0
=============
Tenth public release of Chapel, April 18, 2013
Highlights (see entries in subsequent categories for details)
-------------------------------------------------------------
- added support for regular expression operations on strings and channels
- added support for readf()/writef() routines for formatted I/O
- added support for injecting C declarations into Chapel via "extern blocks"
- added support for associative domain/array literals
- added a capability for main() to take arguments and return a status value
- added support for iteration over homogenous tuples
- performance improvements related to stack-allocated and constant variables
- improved bulk transfer optimization (use -s useBulkTransferStride to enable)
- significant improvements to the Chapel version of LULESH
- enabled GMP using the system-installed version on Cray platforms by default
- switched to using processor atomics for reference counting on Cray systems
- numerous bug fixes and improvements to semantic checks and error messages
Environment Changes
-------------------
- renamed the platform 'cray-cascade' to 'cray-xc'
- renamed the platforms 'xmt'/'xmt-sim' to 'cray-xmt'/'cray-xmt-sim'
- enabled GMP support by default if it is already built in the third-party dir
Syntactic/Naming Changes
------------------------
- added support for associative domain/array literals
(e.g., {"red", "blue"} is an associative domain of strings)
(e.g., ["red" => 0, "blue => 1] is an assoc. array from strings to ints)
Semantic Changes / Changes to Chapel Language
---------------------------------------------
- added support for injecting C declarations into Chapel via "extern blocks"
(see "Support for Extern Blocks" section of doc/technotes/README.extern)
- added support for iteration over homogenous tuples
(see "Tuples" section of the Chapel spec)
- added a capability for main() to take arguments and return a status value
(see doc/technotes/README.main)
- added a 'requestCapacity()' capability to pre-size associative domains
(see "Domains:Predefined Functions" section of the Chapel spec)
- added a warning() routine to generate warnings, similar to halt(), assert()
(see "Standard Modules" section of the Chapel spec)
Newly Implemented Features
--------------------------
- added support for the .localSlice() method to take a domain argument
(e.g., A.localSlice({loRow..hiRow, loCol..hiCol}))
Deprecated Features
-------------------
- removed the tuple() function
(i.e., instead of tuple(x) or tuple(x,y,z), use (x,) or (x,y,z) instead)
- deprecated warning for old-style domain literals by default
(i.e., [1..m, 1..n] is an array of ranges; re-enable w/ --warn-domain-literal)
Standard Modules
----------------
- added support for regular expression operations on strings and channels
(see doc/technotes/README.regexp for details)
- added support for readf()/writef() routines for formatted I/O
(see doc/technotes/README.formattedIO for details)
- refactored communication diagnostics into its own module (CommDiagnostics)
(see doc/technotes/README.comm-diagnostics for documentation)
- added isDomainType(type t)/isArrayType(type t)/isRecordType(type t) queries
Documentation
-------------
- added README.formattedIO to describe support for writef()/readf() routines
(see doc/technotes/README.formattedIO)
- added README.regexp to describe support for regular expression operations
(see doc/technotes/README.regexp)
- added README.main to describe support for arguments/return values for main()
(see doc/technotes/README.main)
- updated README.extern to describe C type aliases and extern blocks
- changed READMEs that used csh-style syntax to use bash-style consistently
- fixed a semantic typo in README.atomics
- minor updates and fixes to various chapters in the language specification
- minor updates to several READMEs
Example Codes
-------------
- improvements to the Chapel implementation of LULESH
(see examples/benchmarks/lulesh/ for more details)
- configuration improvements (see README for details):
- added ability to compute the cube input set rather than reading from disk
- support for 3D vs. 1D representations via 'use3DRepresentation'
- support sparse vs. dense material representations via --sparseMaterials
- added a --maxcycles config that can be used to stop the computation early
- converted 'dtfixed' into a config const
- added a per-iteration timing when doTiming and showProgress are enabled
- code improvements:
- refactored setup code into a helper module: luleshInit.chpl
- changed the representation of nodesets to use a sparse subdomain
- switched to using 'ref' intents rather than 'in' or 'inout'
- converted vars to consts where appropriate
- general code cleanup
- performance improvements:
- improved performance by avoiding an unnecessary reindexing operation
- made some unnecessarily serial loops parallel
- replaced error-oriented reductions with forall loops + halt
- param-unrolled the loop in localizeNeighborNodes() for performance reasons
- removed a redundant zero-initialization of an array
- documentation improvements:
- updated README to document new configuration options
- added the LULESH callgraph to the README
- improved the Chapel implementation of RA:
- added the ability to use an LCG random number generator via 'useLCG'
- added a config const 'verify' that permits verification to be skipped
- fixed a typo in HPL that inflated the calculated GFLOPs by 10x
- improvements to the Chapel implementation of SSCA2:
- fixed a bug in the torus representation
- fixed a bug with VALIDATE_BC=true
Platform-specific Notes
-----------------------
- enabled GMP using the system-installed version on cray-x* platforms by default
Portability of code base
------------------------
- fixed an issue related to vsnprintf on OS X Lion
- fixed an assumption that platforms defining INT8_MIN will also define INT*_MIN
Launcher-specific Notes
-----------------------
- improved use of cnselect in launchers that use 'aprun'
Compiler Flags
--------------
- added --no- variants of the following compiler flags: --count-tokens, --llvm,
--print-code-size, --print-commands, --print-passes, --print-search-dirs,
- added --[no-]warn-tuple-iteration to warn against old-style zipper iteration
(see man page for details)
- added --[no-]warn-special as a meta-flag for all old-style syntax uses
(see man page for details)
- improved support for environment variable setting of '--no-'style flags
(see man page for details)
Error Message Improvements
--------------------------
- improved type mismatch error messages when assigning scalars to arrays
- added an error for extern functions with formal arguments of array type
- made Ctrl-C and the like result in a user, rather than internal, error
- added an error for associative domains with unsupported index types
Bug Fixes / New Semantic Checks (for old semantics)
---------------------------------------------------
- fixed a bug in which sizeof() had leaked into the user namespace in v1.6
- fixed a regression in v1.6 in which type aliases of arrays were broken
- fixed a bug in which 0-element arrays of arrays would free domains prematurely
- fixed a bug related to writing out instances of the RandomStream class
- I/O bug fixes:
- QIO_HINT_PARALLEL now works for new/zero length files
- fixed bugs related to bit-oriented reads and writes
- fixed a bug w.r.t. EOF and preemptive mmap
- fixed portability bug related to Intel compilers
- changed channels so that once EOF is hit, it will never read further
- fixed issues related to ssize_t/int(64) mismatches on 32-bit platforms
- fixed an issue related to reading empty strings
- fixed some bugs in the implementation of atomic variables
- fixed a bug in which AdvancedIters didn't default 'numTasks' as documented
- improved shape checking for array assignment
- restricted reshape() to be applied for rectangular domains only
- restricted reshape() to only work when the source and destination sizes match
- improved support for Cyclic distributions of idxType uint(64)
- fixed INFINITY and NAN to be of type 'real' rather than 'real(32)'
- fixed a bug with '/*/' within a nested comment
- fixed a bug in which uses of ** would dispatch to a user's pow() overload
- fixed a few bugs in the Buffers.chpl module
- fixed a bug in which memory leak tracking would mislabel some allocations
- fixed a bug with recursive iterator inlining
- fixed a bug in broadcasting large values at program startup
Packaging Changes
-----------------
- added Chapel mode support for emacs version 23.x (see etc/emacs/README)
Performance Improvements
------------------------
- switched to using processor atomics for reference counting on Cray systems
- improved bulk transfer optimization (use -s useBulkTransferStride to enable)
- put fewer variables on the heap in the presence of nested functions
- enabled remote value forwarding for more constants/arguments than before
- made atomic variables use compiler intrinsics for cray-prgenv-intel
- made associative domains of 'imag' indices more efficient
Runtime Library Changes
-----------------------
- split chpl_task_begin() to distinguish between new tasks and migrating ones
- improved the ability to build the Chapel runtime with a C++ compiler
Third-Party Software Changes
----------------------------
- updated to version 1.20 of GASNet
- updated to version 1.9 of Qthreads
- made the LLVM checkout script grab version 3.2 to ensure compatability
- removed the nanox tasking layer due to lack of support/champion
Testing System
--------------
- extended the 'skipif' capability to support the ability to skip a subdirectory
- improved the robustness of start_test in cross-compiled environments
- added support for .no-local.good files for --no-local-specific test output
- fixed a bug in which the test system looked at incorrect .future files
- removed artificial limiting of stacksize in start_test
- refactored test system environment setup into util/test/testEnv
- made the test system use $cwd rather than 'pwd'
- made 'nightly' compopts/execopts get added to end of the command line
- made 'nightly' support a --no-futures option
Internal/Developer-oriented
---------------------------
- added some code that sets the groundwork for supporting hierarchical locales
- fixed portability of bswap.h (for once and for all?)
- restructured internal modules corresponding to specific runtime layers
- removed uses of alloca()
- removed PRIM_CHPL_ALLOC_PERMIT_ZERO
- deprecated 'make depend' and made use of gcc -MMD/-MP instead
- made 'rm -rf' commands a little safer in Makefile clean/clobber rules
- refactored Makefiles for Cray systems/compilers to avoid repetition
- added a map_view() function for printing out SymbolMaps
- removed some dead and possibly incorrect methods from Map and Vec classes
- refactored _cast functions for booleans
- made the _isPrimitiveType test more concise
- improved the mechanism by which line numbers are assigned to AST nodes
- factored sync/single out of ChapelBase.chpl and into ChapelSyncvar.chpl
- fixed the --gen-extern-prototypes flag
- improved the correspondence of FLAG_* and string forms of AST flags
- improved the correspondence of PRIM_* and string forms of primitives
- refactored chplrt.h
- added initial support for a .localAccess accessor to Block/Default arrays
- renamed compiler-generated types for classes in generated code
- refactored QIO code in the runtime
- converted macros in the compiler to inline functions for sanity/performance
- cleaned up the functions that build array/domain literals
- refactored and commented lowerIterators.cpp
- keep dtObject alive even if unused after function resolution
- added EOF to the list of reserved symbol names
- protected some C identifiers introduced by PGI when compiling with -Kieee
=============
version 1.6.0
=============
Ninth public release of Chapel, October 18, 2012
Highlights (see entries in subsequent categories for details)
-------------------------------------------------------------
- syntax improvements:
- added support for array literals using square brackets
- improved domain literals to use curly brackets to suggest set notation
- changed zippered iteration to use an explicit 'zip' keyword
- improved atomic variables: new methods, support for floating point atomics
- added support for 'ref' intents to support pass-by-reference arguments
- added support for user overloads of 'op=' and '<=>' assignments
- added a prototype of 'chpldoc', a code-based documentation feature
- added support for using LLVM as a back-end compiler target rather than C
- added support for a strided bulk communication optimization
- numerous performance improvements and bug fixes
- significant improvements to the SSCA2, RA, and LULESH example codes
- added a new tasking runtime that uses U Tokyo's MassiveThreads library
- network-based atomic variables for users of the Chapel module on Cray systems
- improved support for the Tilera chip architecture
Environment Changes
-------------------
- made compiler infer CHPL_HOME if unset, or complain if mis-set
- made util/setchplenv.* scripts more cleanly re-runnable
- added new platforms: 'cray-cascade' and 'cray-xk'
(see doc/platforms/README.cray)
- renamed 'xe-cle' and 'xt-cle' to 'cray-xe' and 'cray-xt', respectively
- renamed Cray PrgEnv compiler settings to be more platform-independent
(e.g., 'cray-xe-cray'/'cray-xe-gnu' -> 'cray-prgenv-cray'/'cray-prgenv-gnu')
- made CHPL_MEM default to 'tcmalloc' when CHPL_COMM is 'ugni'
- made CHPL_ATOMICS default to 'intrinsics' for CHPL_TARGET_COMPILER=PrgEnv-gnu
Syntactic/Naming Changes
------------------------
- changed domain literals to use curly brackets rather than square brackets
(e.g., '[1..n, 1..n]' would now be written '{1..n, 1..n}')
- introduced array literals using square brackets
(e.g., '[3, 5, 7, 11]' describes an array of type '[1..4] int')
- added a 'zip' keyword to express zippered iterations rather than using tuples
(e.g., 'for (a,b) in (A,B)' is now written 'for (a,b) in zip(A,B)')
- added a bidirectional I/O operator (<~>) for reading from/writing to channels
(e.g., 'myChannel <~> myStr;' will read/write 'myStr' from/to 'myChannel')
- added support for creating one-tuples using the syntax (x,)
(e.g., '(1.0,)' describes a tuple of type '1*real')
- re-established the underscore as the means of ignoring a tuple component
(e.g., '(x,,z)' would now be written '(x,_,z)')
Semantic Changes / Changes to Chapel Language
---------------------------------------------
- added support for 'ref' intents, supporting pass-by-reference arguments
(e.g., 'proc foo(ref x: int) ...' passes an int arg to 'foo' by reference)
- improved support for atomic variables
- added support for floating point atomic types
(e.g., 'var x:atomic real;')
- added waitFor(val) method
(e.g., 'x.waitFor(1.0)' would wait for x to hold the value 1.0)
- added non-fetching variations of operations to avoid excess communication
(e.g., 'x.add(1)' is like 'x.fetchAdd(1)' but doesn't return a value)
- added compareExchange() method as a shorthand for compareExchangeStrong()
- added support for user-defined overloads of '<=>' and 'op=' assignments
(e.g., 'proc <=>(ref x: t, ref y: t) ...' or 'proc +=(ref lhs:t, rhs:t) ...')
- added a '.size' method to arrays, domains, strings, and ranges
- made enum types behave more similarly to param ints (or collections thereof)
- removed certain expression forms as being valid types or standalone stmts
Newly Implemented Features
--------------------------
- added a prototype implementation of a code-based documentation feature
(see doc/technotes/README.chpldoc)
- added an LLVM-based back-end
(see doc/technotes/README.llvm)
- added support for degenerate reindexing of non-rectangular arrays
Deprecated Features
-------------------
- removed the '_extern' keyword; use 'extern' instead
- removed the ability to use blanks to drop tuple components -- use '_' instead
Standard Modules
----------------
- made Dimensional Block Cyclic distributions support non-default index types
- added HeapSort() to the standard Sort module
- added the ability to clear() timers without stopping them
Documentation
-------------
- added README.llvm to describe new LLVM back-end option
(see doc/technotes/README.llvm)
- added README.chpldoc to describe new chpldoc documentation option
(see doc/technotes/README.chpldoc)
- updated README.atomics to describe new capabilities for atomic variables
- added doc/platforms/README.tilera to describe using Chapel with Tilera chips
- noted that Python and bc are now required features to build Chapel
(see doc/README.prereqs and doc/platforms/README.cygwin)
- updated README.extern to utilize 'ref' intents rather than 'inout'
- updated language specification to describe new features and syntax changes
- minor updates and fixes to several chapters of the language specification
- updated the Quick Reference to illustrate new syntax, features
- improved command-line help for -d option
- minor updates to several READMEs
Example Codes
-------------
- extensive revisions to SSCA#2 including:
- extensive performance and memory improvements
- improved ability to 'make' with different options from the command line
- changed the neighbor list representation to use 1D arrays of 2-tuples
- added ability to read/write graphs from/to files in setting up
- added support for distributed/parallel graph construction
- fixed a bug in the TEPs computation when starting from a subset of vertices
- added the ability to skip various kernels via configs
- optimized and fixed a bug in the generation of filtered edge lists
- converted uses of sync variables to atomic variables
- improvements to RA:
- extended ra.chpl to use either on-clauses or direct array accesses
- made verification updates lossless using synchronization variables
(see examples/benchmarks/hpcc/ra.chpl)
- added a lossless version of RA that uses atomic variables
(see examples/benchmarks/hpcc/ra-atomics.chpl)
- improvements to LULESH
- replaced 'sync' variables with 'atomic's
- converted a global array into tuples to minimize communication
- general code cleanup improvements
- examples/primer/ updates:
- added a new primer to demonstrate the --docs/chpldoc capability
(see examples/primers/chpldoc.chpl)
- updated atomic_vars.chpl primer to reflect recent changes
- updated arrays.chpl primer to reflect array literal syntax
- updated all examples to reflect syntax changes
Platform-specific Notes
-----------------------
- improved support for the Tilera chip architecture
(see doc/platforms/README.tilera)
- added support for Cray Gemini- and Aries-based atomics to the ugni comm layer
(see doc/platforms/README.cray)
Launcher-specific Notes
-----------------------
- improved error handling of failed forked processes
- for aprun-based launchers:
- made '-cc none' the default mode used
- added -j option to aprun (for supported versions)
- for the pbs-aprun launcher:
- fixed a timing bug
- added a flag --generate-qsub-script
Compiler Flags
--------------
- added --docs and related flags for generating documentation for Chapel code
(see doc/technotes/README.chpldoc)
- added a --gen-extern-prototypes flag to cross-verify extern prototypes
- added an --llvm flag for targeting LLVM as the back-end compiler
(see doc/technotes/README.llvm)
Bug Fixes / New Semantic Checks (for old semantics)
---------------------------------------------------
- fixed a bug with type-inferred module-level domains/arrays
- fixed a bug relating to strings on distributed memory 32-bit platforms
- improved support for uint idxTypes in domains and arrays
- improved the ability to use user-defined constructors in derived classes
- fixed a bug in which the block-cyclic distribution didn't support 1D domains
- fixed several bugs in I/O:
- one related to using stdin on Mac OS X
- one related to bitwise writing
- one related to writing to/reading from a Writer/Reader from a remote locale
- one related to issues on Cygwin
- fixed a bug in which classes were improperly considered unused and removed
- fixed a bug in tcmalloc when computing reallocation growth and shrinkage
Packaging Changes
-----------------
- simplified the etc/emacs/ directory organization to avoid duplication
(emacs users may need to update their .emacs settings -- see etc/emacs/README)
- added a 'chpldoc' alias to the 'chpl' compiler to just generate documentation
- added setchplenv.fish to the release (intended for 1.5.0, but mis-packaged)
- made the subdirectories used to store object files more unique
Performance Improvements
------------------------
- added a strided bulk communication optimization, disabled by default
(to enable, compile with -s useBulkTransferStride)
- replaced internal sync var counters with atomics when appropriate
- made initialization of remote array access caches lazy to reduce setup time
- removed a level of pointer indirection in the implementation of array data
- reduced the runtime cost of creating array aliases
- optimized reindexing for the case when the original and new domains match
- optimized the performance of equality/inequality on identical domains
- made most associative domain/array ops to occur on the owning locale
- enabled remote-value forwarding of array descriptors in the presence of syncs
Runtime Library Changes
-----------------------
- added support for MassiveThreads-based tasking (courtesey U Tokyo)
(see doc/README.tasks)
- added the ability to implement atomic variables using network-based AMOs
- made counters used for communication diagnostics 64 bits to avoid overflow
- turned off the cooperative comm/task non-blocking get interface for GASNet
Third-Party Software Changes
----------------------------
- updated Qthreads to version 1.8
- updated GASNet to version 1.18.2
- added MassiveThreads 0.3beta to the third-party directory
- added a directory to download creoleparser into for use with chpldoc
(see doc/technotes/README.chpldoc)
Testing System
--------------
- reordered the order in which execution options are passed to tests
(see #comments at top of start_test for details)
- added a 'lastexecopts' capability to require an execution option to come last
- improved the 'timedexec' script to kill the child's process group
Internal/Developer-oriented
---------------------------
- significantly refactored the code generation pass
- began the process of replacing homegrown ADTs with STL classes
- removed pragma "inline" (use 'inline' keyword instead)
- renamed some primitives: 'get ref' -> 'deref' and 'set ref' -> 'addr of'
- fixed type-punned pointers in comm-gasnet.c
- fixed a case of deleting global type symbols prematurely
- fixed a use-before-def warning for default-initialized vars of extern type
- added consistency checking to basic block analysis
- made use of BLOCK_TYPE tag more consistent
- reduced reliance on primitives and locale internals in standard modules
=============
version 1.5.0
=============
Eighth public release of Chapel, April 19, 2012
Highlights (see entries in subsequent categories for details)
-------------------------------------------------------------
- completely revamped and improved Chapel's I/O features
- added support for atomic bool/int/uint variables to Chapel
- added a version of the LLNL/DARPA LULESH benchmark
- improved GMP support for integer types
- added an initial implementation of a 2D Dimensional distribution
- added Cray XE (TM)-specific tasking/thread/communication layers for
the Cray XE module (binary only)
- updated GASNet from 1.16.2 to 1.18.0 which includes initial ugni support
- made integers default to 64-bits in most contexts rather than the previous 32-bits
- numerous performance improvements, bug fixes, and documentation improvements
Environment Changes
-------------------
- added support for fish shell users (http://fishshell.com)
(see $CHPL_HOME/README and $CHPL_HOME/util/setchplenv.fish)
Semantic Changes / Changes to Chapel Language
---------------------------------------------
- completely revamped and improved Chapel's I/O features
(see examples/primers/fileIO.chpl, doc/technotes/README.io, I/O spec chapter)
- added support for atomic bool/int/uint variables to Chapel
(see doc/technotes/README.atomics, examples/primers/atomics.chpl)
- added support for /* ... */-style comments to be nested
(e.g., /* in comment! /* in nested comment! */ still in comment! */)
- made integers default to 64-bits in most contexts rather than the previous 32-bits
- integer literals are now of type int(64)/uint(64) by default
- the default 'int'/'uint' types now correspond to int(64)/uint(64)
- the default idxType for ranges, domains, and arrays is now int(64)
- a number of locale-oriented capabilities now use/return 64-bit ints:
- numLocales, LocaleSpace, locale.id
- locale.numCores, locale.callStackSize
- numThreadsPerLocale, maxThreadsPerLocale
- locale.*Threads(), locale.*tasks()
- the 'by' and '#' operators now accept int(w)/uint(w) args for w-bit idxTypes
- param arguments now play a role in disambiguation between function overloads
(see the 'Function Resolution' section in the Chapel language specification)
Newly Implemented Features
--------------------------
- added an initial implementation of a 2D Dimensional distribution
(see examples/primers/distributions.chpl)
- added support for reading arrays, domains, ranges, and tuples
(e.g., var A:[1..10] real; read(A); )
- added support for an iterator's arguments to have intents
- added a new getCommDiagnosticsHere() routine for querying local communications
(see doc/technotes/README.comm-diagnostics)
Deprecated Features
-------------------
- removed support for tensor iteration from the Chapel compiler
(e.g., 'forall (i,j) in [foo(), bar()]' no longer supported; use nested loop)
- removed volatile types in favor of atomic types
- removed the ability to use 'def' to define functions; use 'proc' or 'iter' now
Standard Modules
----------------
- improved GMP support for integer types
(see doc/technotes/README.gmp)
- changed sgn() in Math.chpl to return an int(8)/uint(8)
Documentation
-------------
- major updates to the I/O chapter of the spec to reflect new capabilities
- added a new technical note describing support for atomic types
(doc/technotes/README.atomics)
- revamped technical notes for I/O and GMP to reflect revamped features
(doc/technotes/README.io, doc/technotes/README.gmp)
- minor updates to several other chapters of the language specification
- minor fixes and updates to several READMEs
Example Codes
-------------
- added a version of the LLNL/DARPA LULESH benchmark
(see examples/benchmarks/lulesh/README)
- numerous updates to the Chapel version of SSCA#2
- store visited children in forward pass to avoid recomputing in backwards
- use hand-coded task-private variables to store private variables
- replaced arrays of sync vars with arrays of atomics in most instances
- fixed a number of on-clauses that referred to a poor choice of locale
(see examples/benchmarks/ssca2/README)
- updated hpcc/hpl.chpl to use Dimensional distributions and replicated storage
- moved ssca2 and hpcc examples into a new benchmarks/ subdirectory
- fixed some bugs in hpcc/hpl.chpl
- in ra.chpl, copied manual optimizations from timed loop into verification loop
- updated the arrays.chpl primer to deprecate tensors and improve explanations
Platform-specific Notes
-----------------------
- added Cray XE-specific tasking/thread/communication layers to the
Cray XE module (available using 'module load chapel', see
doc/platforms/README.xe-cle-system-specific-layers)
- fixed GASNet executions on Mac OS X Lion
- generated C identifier lengths are now capped to avoid PGI warnings
Compiler Flags
--------------
- added --max-c-ident-len to cap the length of C identifiers in generated code
Error Message Improvements
--------------------------
- in most contexts, the compiler now prints out a fully-specified type
(e.g., where before it printed 'int', it now prints 'int(64)')
- line number reporting has been improved in certain cases
Bug Fixes / New Semantic Checks (for old semantics)
---------------------------------------------------
- added a compile-time error for incorrect domain slicing cases
- fixed an issue in which users couldn't use 'this' as an identifier
- fixed the ability to delete an object located on a remote locale
- fixed a non-deterministic seg fault for parent classes with types/params only
- fixed a race condition in the implementation of halt()
- fixed an issue in which a .exe filename could not be specified using -o
- the --explain-calls flag now properly displays 'param' intents as such
- protected a user's ability to name variables j0, j1, jn, y0, yn
Performance Improvements
------------------------
- changed array/domain reference counting to use atomics rather than syncs
- made Chapel allocation/free routines inline to reduce overheads
- optimized local on-clauses to reduce overheads by avoiding chpl_comm_fork()
- optimized bulk transfers for Block-distributed arrays that share a domain
- optimized the creation of simple Block- and Cyclic- array aliases
Runtime Library Changes
-----------------------
- no longer count communication threads against numThreadsPerLocale for pthreads
- removed assumption that globals in generated code will have identical addrs
- added support for keeping builds for multiple GASNet segments in one tree
- moved most Chapel module initialization from main() to first task
- simplified the tcmalloc memory layer to support use with GASNet
- added dlmalloc support for communication layers other than GASNet-fast
- broke GASNet AM_signal handler request/reply to use short messages
- fixed a bug in which non-blocking gets could seg-fault
- simplified the initialization and shutdown of the communication layer
- fixed a potential race in broadcasts at program startup
Third-Party Software Changes
----------------------------
- updated GASNet from 1.16.2 to 1.18.0 which includes initial ugni support
- made third-party packages build automatically when needed by the runtime
- updated Qthreads from version 1.7.0 to 1.7.1
- added support for a UTF-8 decoder from Bjoern Hoehrmann for use in the new I/O
- added support for Nanos++ tasking to yield when firing off an active message
- added support for the 'serial' statement to Nanos++ tasking layer
- turned off tcmalloc's tendency to print messages for large allocations
Testing System
--------------
- added the ability for a skipf file to check for substrings in an env. variable
- fixed several bugs in the testing system:
- when using named .good files in compopts files
- when using multiple compopts files and no execopts files
- in the generation of perforamnce data filenames
- condensed how compilation/execution options are identified in testing logs
- added a --logtmp flag to start_test to support single-node parallelism
Internal/Developer-oriented
---------------------------
- fixed an issue in which internal modules resulted in too many circularities
- changed module initialization code so that modules initialize those they use
- added a pragma to control implicit inclusion of ChapelStandard.chpl
- added support for automatically mapping external C types to Chapel types
- added the ability to dump the compiler IR using a text-file format
- added filenames back into the BaseAST class to preserve info during inlining
- added chpl__unsignedType(), chpl__maxIntTypeSameSign() utility functions
- added a typeToString() overload to catch common error cases
- removed debugWrite* capability
- fixed a bug in the compiler's basic block analysis framework
- made existing tests much less sensitive to ordering of output
- added a --[no-]preserve-inlined-line-numbers flag to control inlining behavior
- added a "no instantiation limit" pragma/flag to the compiler
- added an isParameter() method to the ArgSymbol class
- removed strcmps against types to normalize scalar type queries (e.g., int(?w))
- made several refactorings to functionResolution.cpp
- refactored common flag queries into helper query functions
- refactored creation of wrapper functions
- fixed get_int()/get_uint() to avoid reliance on underspecified C int sizes
- made external classes less like Chapel classes within the Chapel compiler
- cleaned up the memory tracking enums associated with the communication layer
- removed chpl_error_noexit primitive
- added code to trace through the disambiguation logic of function resolution
- refactored Makefiles, replacing CHAPEL_ROOT with CHPL_MAKE_HOME
- made third-party/*/Makefile rules more consistent
=============
version 1.4.0
=============
Seventh public release of Chapel, October 20, 2011
Highlights (see below for details)
----------------------------------
- added 'extern', 'export', and 'inline' keywords
- new optimizations for whole-array assignments and remote array accesses
- improved support for Qthreads and Nanos++ tasking, including multi-locale
- added dynamic range iterators via an 'AdvancedIters' module
- continued improving range semantics and implementation
- added support for # operator on dense rectangular domains and arrays
- made associative domain index modifications parallel-safe
- added --static/--dynamic linking flags
- improved communication diagnostics capabilities
- new example codes: SSCA2; primers on sync vars, leader-follower iterators
- updated documentation
- many bug fixes
Syntactic/Naming Changes
------------------------
- renamed '_extern' keyword to 'extern'
- renamed 'maxThreadsPerLocale' to 'numThreadsPerLocale'
(see doc/README.tasks and doc/README.executing for new definitions)
- made it illegal for a string literal to contain an unescaped newline
- renamed dsiIndexLocale to dsiIndexToLocale in domain map standard interface
(see doc/technotes/README.dsi)
- reserved 'ref' as a keyword for future use
- renamed 'iterator' enumeration to 'iterKind' for leader-follower iterators
- renamed 'follower' argument to follower iterators 'followThis'
Semantic Changes / Changes to Chapel Language
---------------------------------------------
- added 'export' keyword to support calling Chapel functions from C
- added 'inline' keyword to force a function to be inlined
- added support to # operator for dense rectangular domains and arrays
- removed support for tensor iteration from the language definition
- removed the realm concept from the language
- ambiguous ranges are now == if their representations match
- disabled promotion of the '..' operator
Newly Implemented Features
--------------------------
- improved qthreads and nanox task layers to support multilocale execution
(see doc/README.tasks)
- adding and removing indices from associative domains is now parallel-safe
- updated the communication diagnostics interface
(see doc/technotes/README.comm-diagnostics)
Standard Modules
----------------
- added an 'AdvancedIters' module with various dynamic scheduling algorithms
- added floor/ceiling/mod functions for integers to 'Math' module
- added new sorting routines to standard 'Sort' module
- added a 'UtilMath' module with other integer ceiling/floor functions
- added a param version of abs() for integers to 'Math' module
Documentation
-------------
- spec updates:
- added a new chapter on 'Interoperability'
- refreshed 'Data Parallelism', 'Task Parallelism', and 'Conversions' chapters
- updated 'Ranges' chapter significantly
- minor updates to 'Domains', 'Arrays', and 'Classes' chapters
- split 'Memory Consistency Model' into its own chapter (still poorly defined)
- documented new Advanced Iterators and Sort routines in 'Standard Modules'
- added documentation about the compiler's module search path to man page/technotes
(see 'man chpl' and doc/technotes/README.module_search)
- added note about parallel safety to doc/technotes/README.extern
- generally refreshed README* and other text-based documentation files
Example Codes
-------------
- added a(n in-progress) implementation of SSCA2 to the release examples
(see examples/ssca2)
- added a primer for sync and single variables
(see examples/primers/syncsingle.chpl)
- added a primer on leader-follower iterators (user-defined forall scheduling)
(see examples/primers/leaderfollower.chpl)
- added an example of creating a private locale view to distributions primer
(see examples/primers/distributions.chpl)
- improved the ranges primer
(see examples/primers/ranges.chpl)
- added a description of subdomains to the domains primer
(see examples/primers/domains.chpl)
- minor wordsmithing for the procedures primer
(see examples/primers/procedures.chpl)
Platform-specific Notes
-----------------------
- improved Makefile settings for IBM/AIX platforms and compilers
Feature Improvements
--------------------
- several improvements to the implementation of ranges
(see 'Ranges' chapter of spec for details)
- made casts-to-string produce the same string as write() does
Compiler Flags
--------------
- added --static/--dynamic flags to specify how the binary should be linked
Interoperability Changes
------------------------
- made 'extern' a keyword; '_extern' is deprecated
Error Message Improvements
--------------------------
- added a compiler warning for param functions with declared return types
- improved a few other difficult compiler error messages
Bug Fixes / New Semantic Checks (for old semantics)
---------------------------------------------------
- fixed the result widths of complex math operations
- improved parsing of escaped characters in string literals
- deleting a record now generates an error
- added a variety of bug fixes for range operations
- fixed a bug with passing strings to external functions for --no-local cases
- fixed a bug for var functions that returned nothing
- fixed a bug related to terminating a CHPL_COMM=gasnet program early
- fixed a bug in which ref temps were not inserted for virtual method calls
- fixed a bug related to removing a label from the AST but not its goto
- fixed bug with applying serial statement to optimized coforall+on loops
- fixed bugs regarding single variables not being treated like sync
- fixed a bug related to incorrect complaints about ambiguous module paths
- fixed a bug related to followers accepting empty ranges
- fixed a few reference-after-deallocation bugs in the compiler
- fixed a bug related to flattening var functions multiple times
Packaging Changes
-----------------
- removed the second-level 'chapel/' directory that releases used to have
- updated emacs/vim modes to bring syntax up-to-date
- util/setchplenv.* scripts now permit $CHPL_HOME to be other than 'chapel'
- added the util/ directory to PATH in the setchplenv.* scripts
- improved make 'clean' and 'clobber' rules for third-party directories
Third-Party Software Changes
----------------------------
- removed requirement to specify LD_LIBRARY_PATHs for qthreads and nanox tasks
- updated to GASNet version 1.16.2 (see third-party/gasnet/README)
- updated Qthreads to version 1.7 (see third-party/qthreads/README)
- added tcmalloc version 1.7 (see third-party/tcmalloc/README)
- updated dlmalloc to version 2.8.5
Runtime Library Changes
-----------------------
- split the 'none' task layer into 'none' and 'minimal'
(see doc/README.tasks)
- added a tcmalloc-based memory layer to the runtime
- improved program initialization order and sequence
- made nanox/qthreads task layers use a #threads==#cores by default
- increased the default callstack size for qthreads tasks
- removed pthread calls from the gasnet communication layer
- began process of unifying runtime file and directory names
- standardized our threading layer interface
- made tasking layers more robust to early calls during program setup
- moved Chapel code in the runtime/ directory into internal modules
Compiler Analysis and Optimizations/Performance of Generated Code
-----------------------------------------------------------------
- added a block transfer optimization for whole-array assignment
- reduced the number of communications for remote Block or Cyclic array access
- added an optimization to remove dead code blocks
Testing System
--------------
- valgrind testing with CHPL_COMM!=none now valgrinds the child processes
Internal
--------
- the threading layer of the runtime now has its own header file
- added a --library flag for creation of a standalone Chapel library
- made normalize_returns() able to be called multiple times
- fixed a bug related to internal module dependences of depth > 2
- added capabilities to help debug deleted AST nodes
(see --break-on-delete-id and --log-deleted-ids-to)
- removed --runtime flag from compiler
- added a compilerAssert() capability
=============
version 1.3.0
=============
Sixth public release of Chapel, April 21, 2011
Highlights (see below for details)
----------------------------------
- split 'def' keyword into 'proc' (for procedures) and 'iter' (for iterators)
(see '$CHPL_HOME/util/convert-defs --help' for help updating existing codes)
- added 'Replicated' distribution and improved 'Block-Cyclic' distribution
(see "Standard Distributions" in spec and examples/primers/distributions.chpl)
- added single-locale task layers for Nanos++ (BSC) and Qthreads (Sandia)
(see doc/README.tasks)
- major reworking of range semantics and implementation
(see "Semantic Changes / Changes to Chapel Language" below for detail)
- initial support for volatile types: bool, int, uint, real, imag
(see doc/technotes/README.volatile)
- support for extern consts and classes (pointers-to-structs)
(see doc/technotes/README.extern)
- improved support for data parallelism on the Cray XMT
- extensive improvements to the sample codes in the examples/ directory
(see 'Example Codes' below and examples/README)
- added most code examples from the spec to a new examples/ directory
(see examples/spec/*)
- added a technical note describing the user-defined domain map interface
(see doc/technotes/README.dsi)
- extensive updates to the language specification
(see 'Documentation' below)
- several improvements to the runtime tasking and communications layers
(see "Runtime Library Changes" below)
Syntactic/Naming Changes
------------------------
- split 'def' keyword into 'proc' (for procedures) and 'iter' (for iterators)
(see '$CHPL_HOME/util/convert-defs --help' for help updating existing codes)
- renamed 'arithmetic' domains/arrays to 'rectangular' domains/arrays
- added support for floating point literals of the form '1.e...'
(previously, only '1e...' and '1.0e...' were supported)
Semantic Changes / Changes to Chapel Language
---------------------------------------------
- several improvements to ranges (see 'Ranges' chapter in the language spec):
- added a concept of alignment to indicate an alignment modulo |stride|
- added an 'align' operator and query to ranges to specify/query alignment
(e.g., '1..10 by 3 align 2' => '2, 5, 8' since 2 == 5 == 8, mod 3)
- defined == on ranges in terms of the integer sequences they generate
- defined ident(r1, r2) to say whether r1 and r2 are semantically identical
- defined '# k' for k < 0 as meaning "count from the end of the range"
- added 'first', 'last', 'alignedLow, 'alignedHigh' methods to ranges
(e.g., '1..10 by -2' => first==10, last==2, alignedLow=2, alignedHigh=10)
- added support for a variety of new range query functions
(e.g., alignLow(), hasFirst(), hasLowBound(), isAligned(), boundsCheck()...)
- added support for volatile bool, int, uint, real, and imag types
(see doc/technotes/README.volatile)
- added an end-of-file check to the file type
(e.g., 'while !infile.eof ...')
- removed support for treating 'return' in iterator as a 'yield'
(e.g., change 'iter foo() { return x; }' to 'iter foo() { yield x; return; }')
- added support to referencing modules without first 'use'-ing them
(e.g., module M1 { var x...} module M2 { ...M1.x... } is now legal)
- added a callStackSize query to the locale type
(e.g., 'here.callStackSize' returns the call stack size on the current locale)
- removed the previously-required semicolon from the end of enum declarations
(e.g., 'enum colors {red, blue, green}' is now legal; previously needed ';')
- added support for a single trailing comma at the end of enum lists
(e.g., 'enum colors {red, blue, green, }' is now legal)
- removed support for +/- operators on rectangular domains; use translate()
Newly Implemented Features
--------------------------
- implemented ==/!= for rectangular, associative, and sparse domains
Standard Distributions
----------------------
- added a first-draft 'Replicated' distribution for storing data redundantly
(see examples/primers/distributions.chpl)
- improved 'Block-Cyclic', sufficient to correctly implement HPCC PTRANS and HPL
(see examples/hpcc/ptrans.chpl, hpl.chpl; examples/primers/distributions.chpl)
- removed redundancy in specification of leader iterators between domains/arrays
Standard Modules
----------------
- added INFINITY and NAN constants to the Math.chpl module
(see 'Math' under "Standard Modules" in language spec)
- added isinf() and isfinite() test routines to the Math.chpl module
(see 'Math' under "Standard Modules" in language spec)
- added a half dozen more routines to the GMP.chpl module
Documentation
-------------
- added a new technical note describing the user-defined domain map interface
(see doc/technotes/README.dsi)
- made many improvements to the language specification
- major revisions to the Domains chapter to improve clarity/accuracy
- improved and unified structure of Records and Classes chapters
- major revisions to the Domain Maps chapter to improve clarity/accuracy
- named example codes to provide cross-reference to examples/spec/ programs
- clarified the legality of label/break/continue in parallel loops
- updated the descriptions of read[ln]/write[ln]
- fixed some problems in file fields ordering
- reformatted the specification as a 'book' in LaTeX
- various minor fixes of typos/mistakes
- improved definitions/descriptions of several terms
- added documentation of locale.name
- and many other changes...
- updated quick reference document to include def->proc/iter change, align op.
- rewrote/reorganized README.extern to clarify explanations and bring up-to-date
- added a README describing the 'local' statement (doc/technotes/README.local)
- added a README describing volatile types (doc/technotes/README.volatile)
- updated README.comm-diagnostics to mention fast fork statistics
- updated various README files
Example Codes
-------------
- placed most code examples from the language spec. to a new spec/ subdirectory
- improved the primers/ directory:
- added a new primer for using procedures (primers/procedures.chpl)
- added a basic primer for domains (primers/domains.chpl)
- renamed the locales primer to locales.chpl and improved it
- improved the distributions primer and added Block-Cyclic and Replicated uses
- updated the range primer (primers/range.chpl)
- improved the iterators primer (primers/iterators.chpl)
- improved the reductions primer (primers/reductions.chpl)
- added getCurrentTime() to the timers primer (primers/timers.chpl)
- added descriptions of type aliases and config types to variables primer
(see primers/variables.chpl)
- improved hpcc/ benchmarks directory
- added first version of HPCC PTRANS to hpcc/ directory (ptrans.chpl)
- added cleaner version of HPCC HPL to hpcc/ directory (hpl.chpl)
- added a variants/ subdirectory to examples/hpcc to exhibit other approaches
- added stream-promoted.chpl to show use of promotion in global STREAM Triad
- added ra-cleanloop.chpl to show cleaner (but currently slower) RA kernel
- improved top-level examples:
- renamed existing "hello, world" examples to suggest a logical reading order
(see examples/hello*.chpl)
- added data parallel and distributed data parallel hello, world examples
(see examples/hello3-datapar.chpl, examples/hello4-datapar-dist.chpl)
- added comments to the various hello, world examples (examples/hello*.chpl)
- updated all examples to current language semantics
- use 'proc'/'iter' rather than 'def'
- update to reflect new range semantics
Platform-specific Notes
-----------------------
- for Cray XT/Cray XE, improved the aprun and pbs-aprun launchers
(see "Launcher-specific notes" below)
- for Cray XMT, added support for parallel loops over ranges
- for Cray XMT, added generation of noalias pragmas to forall loop variables
- added support for BSC's MareNostrum including docs and a special launcher
(see doc/platforms/README.marenostrum)
Launcher-specific notes
-----------------------
- added launcher-specific options to --help capability
- improved propagation of exit status codes through launchers
- changed launchers to support exec-based (rather than system-based) commands
- made launchers use 'unlink' rather than system('rm') to remove temporary files
- added a launcher for BSC's MareNostrum
- reduced number of temporary files used to capture output of 'system' commands
- aprun launcher improvements:
- added a --cc flag to specify CPU assignment w/in a node
- added a -q flag to run the launcher in quiet mode
- added debug capability via CHPL_LAUNCHER_DEBUG to keep tmp files around
- pbs-aprun launcher improvements:
- added a --cc flag to specify CPU assignment w/in a node
- added debug capability via CHPL_LAUNCHER_DEBUG to keep tmp files around
- cleaned up output to get rid of some extraneous printing
- made launcher support our testing system
- added --walltime and --queue flags to launcher as alternatives to env. vars.
Compiler Changes
----------------
- made the compiler print 'true'/'false' out in type signatures rather than 1/0
- added config param 'noRefCount' to disable reference counting (may leak memory)
Compiler Flags
--------------
- added a --print-callstack-on-error flag to show what led to a bad call
- added a --no-codegen flag to skip the code-generation and linking phase
Interoperability Changes
------------------------
- added support for extern C "classes" (pointer-to-struct types)
- added support for extern consts (see README.extern)
Error Message Improvements
--------------------------
- added a warning orphaned 'use' statements outside of declared modules
(e.g., 'use M1; module M2 { }' should typically be 'module M2 { use M1; }')
- made parse-time error message use the standard 'filename:lineno:' format
- generated an error message for referring to a class name in a primary method
(e.g., 'class C { def C.m() {...} }' now generates an error message)
Bug Fixes / New Semantic Checks (for old semantics)
---------------------------------------------------
- prevented config types from being set using execution time command-line flags
- fixed the compiler's ability to handle unions with no fields
- fixed the minloc/maxloc reductions to handle empty ranges/subranges of values
- fixed a bug in which the 'path' argument to file constructors was ignored
- made empty unions work correctly
- fixed an overflow issue in chunking up ranges for distribution/parallelization
- fixed a bug involving support for empty extern record types
- fixed a bug involving extern functions that return records
- fixed a bug related to copying external records
- fixed implementation of +/- operators on associative/sparse domains
- fixed a bug relating to filename-based module names containing multiple '.'s
- added error messages for expand/exterior/interior on irregular domains
- added an error for constructors/destructors with a specified return type
- fixed a pair of bugs relating to the 'fast on' optimization
- added a check against constructing classes without specifying generic fields
Packaging Changes
-----------------
- added syntax highlighter code for GNU source-highlight
(see etc/source-highlight/README)
- improved emacs coloring support for version 22.x
(see etc/emacs/README)
- updates to vim syntax coloring to reflect new 'proc'/'iter' keywords
(see etc/vim/README)
- added a script for converting existing codes' use of 'def' to 'iter'/'proc'
(see $CHPL_HOME/util/convert-defs)
- removed multirealm examples & documentation for the time being
Third-Party Software Changes
----------------------------
- updated GASNet to version 1.16.1
- added copies of BSC's Nanos++ and Sandia's Qthreads
(see third-party/README)
- made a post-install step for GASNet that changes absolute paths to relative
- removed PVM for the time being due to instability
Runtime Library Changes
-----------------------
- added single-locale task layers for Nanos++ (BSC) and Qthreads (Sandia)
- several improvements to the runtime tasking layer:
- added a new interface for having the tasking layer call chpl_main()
- changed tasking init function to take maxThreadsPerLocale/callStackSize args
- added a task yield capability to the tasking layer interface
- improved runtime code to avoid using sync vars before initializing tasking
- removed macro-ized form of tasking interface; using standard names instead
- unified naming of all task layer routines to chpl_sync_*() and chpl_task_*()
- removed requirement to implement the single variable interface
- moved termination of threads from fifo tasking layer to pthreads threading
- simplified implementation of sync variables in the pthread threading layer
- moved responsibility for thread counts from fifo tasking to pthread threading
- several improvements to the runtime communication layer:
- restructured the communication interface to support length/type arguments
- added an interface for non-blocking get operations to the comm. interface
- unified all remote get operations to use CHPL_COMM_GET() macro
- refactored/renamed the communication interface headers
Testing System
--------------
- vastly improved the performance testing and graphing capabilities
(see comments at the front of start_test for documentation)
- improved the testing system's support for cleaning up after itself
- added ability to avoid using any indirection of stdin
- added an option to provide a system-wide prediff option
- added ability to use a launcher's native timeout feature rather than Python's
- improved how the testing system kills a test that times out
- fixed a bug in which .preexec files only worked if '.' was in your path
Internal
--------
- added a --break-on-id compiler flag for developers to locate AST node creates
- improved organization of util/ directory contents
- changed the way version numbers are computed/displayed for SVN-based users
- added support for task-/thread-specific module code
- added a capability to print the AST counts allocated between each pass
- added a new gdb alias to compiler --gdb: 'loc' prints an AST node's location
- greatly improved implementation of pragmas/flags to avoid error cases
- removed several instances of unnecessary string comparisons in the compiler
- removed error-prone use of CHPL_TASKS and CHPL_THREADS as preprocessor symbols
- added bestPractices documentation for developers (not included in release)
- changed internal munging of '=' and '==' to 'ASSIGN' and 'EQUALS' respectively
- added a --print-id-on-error developer flag to print AST ID on errors
- improved the strictness of C++ prototype checking
- added external contributor agreements to the SVN tree (not in release)
- added a notion of internal types used by the compiler but not the user
=============
version 1.2.0
=============
Fifth public release of Chapel, October 21, 2010
High-Level Themes
-----------------
- single- and multi-locale task parallelism
- improved single- and multi-locale data parallelism
- single- and multi-locale parallelism for arithmetic domains/arrays
- single-locale parallelism for sparse and associative domains/arrays
- serial reference version of opaque domains/arrays
- improved stability and portability
Highlights
----------
- support for parallel iteration over sparse and associative domains and arrays
- added support for the Cray XE6 (TM) and Cray CX1000 (TM)
- improved parallelization of loops for the Cray XMT (TM)
- support for config types and improved support for config params
- improved support for external C types, vars, and functions
- initial support for first-class and anonymous functions
- prototype implementation of a GMP multiprecision math module
Environment Changes
-------------------
- renamed the 'cx1-linux' platform variable to 'cx-linux'
Syntactic/Naming Changes
------------------------
- renamed the range's index type from 'eltType' to 'idxType'
- made string length a parenthesis-less method rather than a standalone function
(i.e., 'length(mystring)' should now be written 'mystring.length')
Semantic Changes/Changes to Chapel Language
-------------------------------------------
- added initial support for first-class and anonymous functions
(see doc/technotes/README.firstClassFns)
- added support for config types
- enabled config params to support very general command-line expressions
- added support for param 'this' arguments to methods
- added support for assigning tuples of ranges to arithmetic domains
- added support for .stridable and .stride queries on domains
- changed the range's stride type from an int to a signed int of the index type
(e.g., range(uint(64)) and range(int(64)) now store an int(64) stride value)
- made the by operator for a range accept the range's idxType or its stride type
- added min()/max() functions for tuples that fill the tuple with min/max vals
(see 'Tuples' chapter of language spec)
- added isTupleType(type t) param function that tells whether t is a tuple
- made a dataParTasksPerLocale value of '0' evalute to here.numCores
- converted dataParMinGranularity from a uint to an int and made its default '1'
- made numBits/numBytes for default-width bools generate a compiler error
Newly Implemented Features
--------------------------
- added support for parallel iteration over sparse domains/arrays
- added support for parallel iteration over associative domains/arrays
- added support for sparse strided domains
- added support for printing of default layout arrays with negative strides
- fixed iteration over/printing of default layout arrays with negative strides
- implemented initialization of strided arrays by tuples
- added the ability to slice a domain with another domain
- added support for localSlice method on arrays with default layout
- added support for indexToLocale method on the default layout
Standard Domain Maps
--------------------
- made default sparse and associative domains/array layouts support parallelism
Standard Modules
----------------
- added a prototype GMP (GNU Multiple Precision Arithmetic) module
(see doc/technotes/README.gmp)
Platform-specific notes
-----------------------
- added support for the Cray XE6 (TM) via a new platform variable xe-cle
(see doc/platforms/README.xe-cle)
- added support for the Cray CX1000 (TM) as part of the cx-linux platform
(see doc/platforms/README.cx-linux)
- added support for using LSF as a launcher for cx-linux via lsf-gasnetrun_ibv
- for xt-cle/xe-cle:
- made MPI the default conduit due to portals conduit issues in GASNet 1.14.x
- added support for specifying dynamic vs. static linking
(see doc/platforms/README.xt-cle or .../README.xe-cle)
- made the default launcher depend on the availability of pbs/aprun
(see doc/platforms/README.xt-cle or README.xe-cle)
- for xmt:
- improved the parallelization of operations on default layout arrays/domains
- made XMT compilations ignore dmapped annotations on domains
Documentation
-------------
- improved the language specification to improve clarity, fix bugs
- updated the various READMEs, text files, and man page
Example Codes
-------------
- switched hpcc benchmarks to use sugared form of dmapped for clarity
Packaging Changes
-----------------
- moved test system helper scripts from test/Bin to util/test
- added ability for multiple communication substrate builds to coexist at once
Compiler Changes
----------------
- converted the compiler version to the format: major.minor.update
Third Party Changes
-------------------
- updated to GASNet version 1.14.2
- added GMP (the GNU Multiple Precision Arithmetic Library)
Runtime Library Changes
-----------------------
- improved the implementation of the fast fork optimization
- removed the mutex-related calls from the tasking layer interface
Launcher-specific notes
-----------------------
- made the pbs-aprun launcher use options to qsub rather than a script file
Compiler Flags
--------------
--report-scalar-replace : print statistics about scalar replacement
--scalar-replace-limit : sets the max size of variables replaced (default=8)
--[no-]tuple-copy-opt : enables tuple assignment optimization
--tuple-copy-limit <limit> : limits size of tuples for --tuple-copy-opt
Execution Flags
---------------
--callStackSize : specify the task call stack size
(see doc/README.executing and doc/README.tasks)
Interoperability Changes
------------------------
- improved ability to express external C functions, types, and variables:
- added support for external type and variable declarations
- added support for expressing and passing external C array types
- added support for type arguments to an external function
(see doc/technotes/README.extern)
Bug Fixes/New Semantic Checks (for old semantics)
-------------------------------------------------
- fixed a bug in multiplying two imag values
- added a check to prevent comparisons between types and values using == or !=
(e.g., 'var x = ...; type t = ...; ...(x == t)...' is now illegal)
- added a check to ensure tuple-style decls match the size of their initializer
(e.g., 'var (x, y) = (1, 2, 3);' will now generate an error)
- fixed a pair of nil pointer dereference bugs in the Cyclic distribution
- made string.length return an 'int' as documented rather than an 'int(64)'
- fixed a bug in which the compiler seg faulted if no .chpl files were given
- generate a compiler error when applying '#' to a completely unbounded range
(i.e., ".. # 10" is now a compiler error)
- fixed a bug in which queried argument types sometimes became void incorrectly
- made values of dataParTasksPerLocale and dataParMinGranularity < 0 an error
- added a check to make sure maxThreadsPerLocale >= 0
- fixed a race condition in the initialization of the fifo tasking layer
- fixed a bug in which functions returning enums were flagged as not
- fixed a bug in which failing to capture an iterator caused it not to be called
- removed a race condition on calling halt() from multiple tasks in a locale
Error Message Improvements
--------------------------
- 'illegal use of a function that does not return a value' now says which fn.
Compiler Analysis and Optimizations/Performance of Generated Code
-----------------------------------------------------------------
- improved the compiler's ability to narrow wide references when possible
- optimized small tuple assignment to use scalar assignment rather than memcpy
- turned the --localize-global-consts flag on by default
- removed empty records from the compiler's intermediate representation
- improved scalar replacement for nested records
Testing system
--------------
- added ability for testing system to generate graphs in performance mode
(see comments in start_test for details)
Internal
--------
- added documentation on compiler arch. to doc/developer/compilerOverview (SVN)
- refactored the $CHPL_HOME/util directory into several subdirectories
- refactored third-party directory and Makefiles
- generally removed file extensions from shell scripts
- made internal version number take the form: major.minor.update.svnrev
- made the compileTest script more robust w.r.t. -I, -M, .h, etc. arguments
- cached the number of processor cores in the locale type
- added versions of compilerError and compilerWarning that take a call depth
- reduced the number of runtime files that get rebuilt when the compiler changes
- simplified the implementation of associative arrays to reduce copies/temps
- removed the 'size' field from the default arithmetic array class
- made our implementation of Norm.chpl use slicing rather than rank change
- replaced the isEnumType primitive with calls to _isEnumeratedType()
- replaced several primitives with extern functions
- added a new repositionDefExprs pass to make local variables safe on XMT
- added --local-temp-names flag to use a different temp naming scheme
- changed the --gen-communicated-structures developer flag to --heterogeneous
=============
version 1.1.2
=============
Update to fourth public release of Chapel, September, 2010
(see also changes below for 1.1.1 and 1.1)
Platform-specific notes
-----------------------
- added an xe-cle PLATFORM to support the XE6 (currently using GASNet over MPI)
(see doc/platforms/README.xe-cle for details)
=============
version 1.1.1
=============
Update to fourth public release of Chapel, July 8, 2010
(see also changes below for 1.1)
Platform-specific notes
-----------------------
- removed dependence on linking against libpct on Cray XTs
- fixed a bug in which linux did not use 'make' if 'gmake' was unavailable
Bug fixes
---------
- fixed a race condition in our mutex initialization code
- fixed a bug in fillRandom() in which using a clock-based seed did not do so
===========
version 1.1
===========
Fourth public release of Chapel, April 15, 2010
High-Level Themes
-----------------
- single- and multi-locale task parallelism
- improved single- and multi-locale data parallelism
- all data parallel operations on arithmetic arrays are now parallelized
- improved control over task quantity and granularity for data parallelism
- improved completeness and stability of Block and Cyclic distributions
- bug fixes
Environment Changes
-------------------
- added CHPL_TASKS to select the tasking layer to use (was CHPL_THREADS)
(see doc/README.chplenv and doc/README.tasks for details)
- CHPL_THREADS now describes lower-level threading and is typically inferred
(see doc/README.tasks)
- changed the name of the default tasking layer from 'default' to 'fifo'
(see doc/README.chplenv and doc/README.tasks)
- added CHPL_TIMERS to select between timer implementations
(see doc/README.chplenv)
- changed the CHPL_*_PLATFORM string for 32-bit linux from 'linux' to 'linux32'
(see doc/README.chplenv)
Syntactic/Naming Changes
------------------------
- several changes related to the naming and syntax of distributions:
- renamed "distributions" to "domain maps" (or 'dmap's in Chapel syntax)
- redefined the term "distributions" to refer to multi-locale domain maps
- defined the term "layouts" to refer to single-locale domain maps
- replaced placeholder 'distributionType'/'distributionValue' with 'dmap'
(e.g., 'const D = distributionValue(...)' => 'const D = new dmap(...)'
- changed the 'distributed' keyword to 'dmapped'
- added a syntactic sugar to drop 'new dmap(new' for anonymous domain maps
(e.g., '...dmapped new dmap(new Block(...))...' => '...dmapped Block(...)')
(see 'Domain Maps' chapter of language specification for more information)
- renamed maxThreads to maxThreadsPerLocale (see README.tasks)
- renamed the 'ind2loc' method on domain maps to 'idxToLocale'
- renamed the Cyclic constructor 'low' argument to 'startIdx'
(see 'Standard Distributions' chapter of the specification)
- replaced the use of underscore (_) to ignore things to leaving the space blank
(e.g., '(_, x) = getTuple()' => '( , x) = getTuple()')
- made underscore (_) a legal identifier
- changed name of the Random module's SeedGenerator from clockMS to currentTime
(see 'Standard Modules' chapter of the specification)
- added support for empty (no-op) statements within a class declaration
- added ability to elide the # of arguments specification/query from varargs fns
(e.g., can now do 'def f(x...)' in addition to 'def f(x...?n)'/'def f(x...n)')
Semantic Changes/Changes to Chapel Language
-------------------------------------------
- added config consts to control the number of tasks used for data parallelism
(see README.executing and 'Data Parallelism' chapter of specification)
- redefined enumerated domains to be a special case of associative domains
(see 'Domains' chapter of specification)
- made iteration over enumerated domains/arrays use the enum's declaration order
(see 'Domains' chapter of the specification)
- removed the ability to assign array aliases to normal array variables
(e.g., 'var A => B;' is legal but 'var A: [1..n] real; A => B;' is not)
- added initial support for passing array aliases to default class constructors
(e.g., 'class C {var X: [1..n] int;} var A: [1..n] int; var c = new C(X=>A);')
- removed the sugar for declaring array types with forall expressions:
(e.g., 'var A:[i in 1..n] real =...' => 'var A:[1..n] real = [i in 1..n] ...')
- defined reindexing to ignore the domain map of the indexing domain
- specified that minloc/maxloc reductions return the lowest matching index
(e.g., 'minloc (A, 1..3)' for A = '5 0 0' would return (0, 2))
- type aliases may now only be used after they are defined
(e.g., 'var x: t; type t = int;' is now illegal)
- changed resolution to favor functions with where clauses over those without
(e.g., for 'foo(3)', 'foo(x)' is not as good a match as 'foo(x) where x:int')
(see 'Function Resolution' section of the specification)
- added the ability to index into 1-dimensional arithmetic arrays using 1-tuples
(e.g., 'var i: 1*int; ... A(i)' where A is a 1D arithmetic array)
- added the ability to query the component types of formal tuple arguments
(e.g., 'def f(t: (real, ?t)) { ... }')
- redefined order-of-evaluation of tuple assignments to avoid array temps
(see 'Tuples' chapter of specification)
- added support for indexing into tuples using any integral type, not just 'int'
(e.g., given a tuple variable t, 'var i = 1:uint; ...t(i)...' is now legal)
- added support for 1-tuple detupled variable declarations for completeness
(e.g., in 'var (x): 1*int;', x is of type 'int')
- redefined assignments to evaluate the left-hand side before the right
(e.g., in 'x = y;', x is evaluted first and then y)
Newly Implemented Features
--------------------------
- whole-array assignment now results in parallel execution for arithmetic arrays
(e.g., 'A = B; and 'A = B + alpha * C' now result in parallel execution)
(see 'Data Parallelism' chapter for details)
- added support for assigning to a variable of dmap type if it has no domains
(e.g., 'var myMap: dmap(Block(2)); myMap = new dmap(new Block([1..10]));')
- can now apply domain maps to domain values rather than simply domain types
(e.g., 'const Dom1 = [1..10] dmapped ...')
- added support for sparse domain assignment (executed serially with a warning)
- added support for removing indices from a sparse domain (not thread-safe)
- added support for declaring formal tuple arguments of explicit tuple types
(e.g., 'def f((x, y): (int, real)) { ... }')
- improved support for zippering domains/arrays with distinct domain maps
Standard Domain Maps
--------------------
- the Block and Cyclic distributed domain maps are now feature-complete
- added reindexing and rank change operations to the Block distribution
- reordered Block's constructor args so that rank and idxType can be inferred
(e.g., 'new Block(rank=1, idxType=int(64), [1..n])' => 'new Block([1..n])')
- similarly reordered Cyclic's constructor args and renamed 'low' to 'startIdx'
- made int(32) the default idxType for standard distributions like Block
- moved all standard domain maps into modules/layouts/ and .../distributions/
- factored common routines for arithmetic domains into ChapelArray.chpl
(e.g., nothing about exterior() is specific to a domain map's implementation)
- refactored helper functions for distributions into a new file: DSIUtil.chpl
Standard Modules
----------------
- refactored the code in the Random module and improved the implementation
- changed the Random module's SeedGenerator to an enumerated type
- added support for filling random vectors of imaginary types
Platform-specific notes
-----------------------
- added an mtarun launcher for the Cray XMT
(see README.launcher)
- on the Cray XMT added support for platform-specific timing routines
(see README.chplenv)
- for the Cray XMT, fixed a bug with uninitialized variables and poison bits
Portability of code base
------------------------
- ported code base to recent versions of NetBSD (thanks to Phil Nelson)
- removed hard-coded paths to perl and bash in scripts, relying on /usr/bin/env
- added parentheses around some expressions to avoid compiler warnings
Documentation
-------------
- updated the STATUS file
- added the first description of using domain maps to the specification
(see 'Domain Maps')
- performed a major restructuring of the language specification:
- split the 'Domains and Arrays' chapter into two distinct chapters
(see the 'Domains' and 'Arrays' chapters)
- split the 'Parallelism and Synchronization' chapter of the spec into two
(see 'Task Parallelism and Synchronization' and 'Data Parallelism')
- moved the 'Reductions and Scans' chapter of the spec into 'Data Parallelism'
- moved discussion of promotion into the 'Data Parallelism' chapter
- split the 'Locales and Distributions' chapter of the spec into three
(see 'Locales', 'Domain Maps', and 'User-Defined Domain Maps')
- reordered the chapters of the specification for clarity
- added a placeholder chapter to the specification for user-defined reductions
(see 'User-Defined Reductions and Scans')
- added a 'Standard Distributions' chapter that describes Block and Cyclic
- added a placeholder chapter for 'Standard Layouts'
- improved the specification:
- added a publication date to the title page of the specification
- updated the operator precedence table in the specification
(see 'Lexical Structure' chapter)
- improved the specification's syntax diagrams for [co]for[all] loops
- minor improvements to the 'Modules' chapter of the specification
- made major improvements to the 'Tuples' chapter
- improved the accuracy of the description of function resolution
- reorganized/rewrote the 'Domains' and 'Arrays' chapters (more remains)
- improved the consistency of prototypes in the 'Standard Modules' chapter
- updated the description of the Random number module to reflect changes
- fixed several bugs in example codes within the specification
- added doc/platforms/README.xmt to describe the use of Chapel on a Cray XMT
- added doc/platforms/README.sgi to describe the use of Chapel on an SGI Altix
- updated READMEs based on task/thread change
(see doc/README.tasks and doc/README.executing)
- added a README to the $CHPL_HOME/util directory to describe its contents
- updated READMEs for clarity and accuracy
- reformatted the CONTRIBUTORS file to reflect contributors to a given release
- updated the quick reference card's contents
Example Codes
-------------
- added a new example 'distributions.chpl showing use of Block and Cyclic
- removed 'block2D.chpl' example, considered redundant with the above
- added a new example to show simple multitasking (hello-multicore.chpl)
- renamed the 'examples/tutorials' directory 'examples/primers'
- rewrote the taskParallel.chpl primer example program
- updated all examples to reflect language changes:
- to reflect new dmap/dmapped syntax for specifying domain maps
- the change of Block and Cyclic's default idxType to int(32)
- to remove reliance on the 'A:[i in ...]' syntactic sugar for array decls
- to remove the use of underscores to represent ignored values
- to track the changes to the Random module interface
- to reflect the new controls for specifying degree of data parallelism
- to reflect the new constructor argument orders for Block and Cyclic
- to reflect the renaming of ind2loc to idxToLocale
- renamed helper files in hpcc/ subdirectory to match the modules they define
- updated comments in ra-randstream.chpl, quicksort.chpl
- stopped unrolling a loop in ra-randstream.chpl's computeM2Vals routine
- added hpcc/stream-ep to the Makefile and README (overlooked in last release)
Packaging Changes
-----------------
- pushed tarball directory structure down one level (i.e., chapel-1.1/chapel)
- moved non-user scripts from $CHPL_HOME/util/ to $CHPL_HOME/util/chplenv/
Compiler Changes
----------------
- added warnings for most serialized data parallel operations
- added warnings for array reindexings using strided ranges/domains
- improved orthogonality of parsing type expressions in expression contexts
- turned off optimizations by default for CHPL_COMM=gasnet; use -O to enable
- reimplemented scans to remove the creation of a temporary array
Runtime Library Changes
-----------------------
- reorganized the runtime directories to use better hierarchies
(e.g., 'runtime/foo-bar' => 'runtime/src/foo/bar'
- broke the threading layer of the runtime into tasking and threading layers
- renamed most external tasking/threading routines in the runtime interface
- added support for different timer implementations and platform-specific timers
- renamed chapel_code.chpl to chpl_rt_utils.chpl
- exposed sleep() calls to the tasking layer
Launcher-specific notes
-----------------------
- added an mtarun launcher for the Cray XMT
Compiler Flags
--------------
- --conditional-dynamic-dispatch-limit flag for using vtables vs. conditionals
- --[no-]fast-followers to control optimization of aligned parallel iterators
Interoperability Changes
------------------------
- added initial support for declaring external C struct types
(see doc/technotes/README.extern for details)
Bug Fixes/New Semantic Checks (for old semantics)
-------------------------------------------------
- removed the ability to assign values to types
- added a check that config param enums are set to a legal value for the enum
- added a check that tuple assignments are between tuples of matching size
- added a check that iterators are not defined to yield types or params
- added a check to ensure zippered sparse domains/arrays share the same domain
- added an error message for param for loops that iterate over non-param ranges
- fixed a bug in which a shared initializer was evaluated multiple times
(e.g., 'var x, y, z = foo()' called foo() three times rather than one)
- fixed a bug in which yield statements could omit the expression to yield
(i.e., 'yield;' is not a legal statement in Chapel)
- fixed a bug in which applying .locale to a global variable always returned #0
- fixed a few race conditions in the runtime tasking layer
- fixed an integer overflow problem in the locale.physicalMemory() query
- fixed a runaway recursive error message in erroneous CHPL_COMM=gasnet exits
- fixed a bug in associative domains in which stale array values were not reset
- fixed bugs in which argument coercion and promotion broke extern functions
- fixed a bug in which a 'use' in a module-level non-function scope leaked names
- fixed a bug where returning a sync var was flagged as not returning anything
- fixed a bug in which generic class member types could not be queried
- fixed a bug in which a class' type declaration could not define multiple types
- fixed a bug in which printing an empty record would print an internal field
- fixed a bug in which recursive fns in local blocks led to infinite compilation
- fixed bugs in function resolution that led to choosing a poorer match
- fixed implementation of type aliases to evaluate them during fn resolution
- fixed a bug in the visibility of parallel iterators in promotion wrappers
- fixed a bug in dead code elimination considered already eliminated code
- fixed a bug in which compiler warnings were sometimes not generated
- fixed a bug in which standalone forall loops incorrectly localized references
- fixed a bug in flattening nested functions that removed non-dead references
- fixed a bug in which the compiler would incorrectly drop line#/filename info
- fixed a bug in which duplicating a loop would not update its labels
- fixed the instantiation point for compiler-introduced wrapper functions
- fixed a bug in which "false" where clauses were counted as instantiations
Error Message Improvements
--------------------------
- squashed "too many instantiation" error messages for internal types/functions
- somewhat improved the error message for applying 'new' to a non-class
Compiler Analysis and Optimizations/Performance of Generated Code
-----------------------------------------------------------------
- turned on optimizations of on-clauses by default (--optimize-on-clauses)
- re-implemented homogenous tuples to use C arrays rather than structs
- generated new loop idioms to replace fragile static alignment analysis
- Cyclic distributions now result in similar performance to Block for e.p. codes
- added the ability to use a virtual method table for dynamic dispatch
Compiler Performance and Cleanup
--------------------------------
- reordered compiler optimizations to improve performance
- rewrote copy propagation to remove a quadratic aspect of the algorithm
- changed conditional-based dynamic dispatch to use statements rather than exprs
- improved performance of function resolution
- improved performance of the reaching definitions analysis
Cleanup of Generated Code
-------------------------
- made generated code less sensitive to small changes to better support diffs
- broke user code within chpl_main() into its own function: chpl_user_main()
Testing system
--------------
- added ability to test properly formatted codes embedded in the specification
- changed sub_test script to use Python for better flexibility/maintainability
- fixed the redundant cleaning of directories when tests are explicitly named
- made sub_test clean up executables for .noexec tests
Internal
--------
- added a developer optimization to localize global constants (off by default)
- added a new helper function gen() that serves as a printf for codegen
- added a debugging function printCallStack() for use during function resolution
- added a new mechanism for building the IR after parsing, before normalization
- refactored parser to treat types and expressions more uniformly
- refactored parsing of serial and parallel loops to share more code
- simplified the implementation of operator overloading on tuples
- cleaned up the implementation of reductions
- reimplemented Math.chpl routines using _extern rather than primitives
- reimplemented most Memory.chpl routines using _extern rather than primitives
- generalized a mechanism for soft-resolving a possibly erroneous function call
- added a displayRepresentation method to dmap, domain, and array classes
- removed the unused 'reindexed' param from default arithmetic arrays
- added the "dsi" prefix to methods that are part of the dmap standard interface
- better distinguished between thread and task IDs
- added getValType(), getRefType(), getWideRefType() helper functions
- added support for _isSignedType() and isUnsignedType() helper param functions
- moved the implementation of queries in formal types to function resolution
- simplified the generation of BUILD_VERSION for non-developers
============
version 1.02
============
Update to third public release of Chapel, November 12, 2009
(see also changes below for version 1.01 and 1.0)
High-Level Themes
-----------------
- single- and multi-locale task parallelism
- single- and multi-locale data parallelism
- improved performance and scalability
- bug fixes
Packaging Changes
-----------------
- added GASNet 1.14.0 to third-party/ though 1.12.0 is still the default
(see third-party/gasnet/README)
Runtime Library Changes
-----------------------
- vastly improved the performance of CHPL_COMM=pvm, esp. when oversubscribing
Documentation
-------------
- removed the HPCC-related PDFs from doc/ as they seem better suited for the web
Example Codes
-------------
- added an EP version of stream to showcase Chapel in an SPMD-like mode
(see $CHPL_HOME/examples/hpcc/stream-ep.chpl)
- added local blocks to ra.chpl and fft.chpl to assert regions of locality
- changed fft.chpl to use both Block and Cyclic arrays to optimize for locality
Standard Distributions
----------------------
- optimized the Block distribution via privatization and remote value forwarding
- added support for a .localSlice() operation for Block and Cyclic array
- optimized away some extraneous copies from standard distributions
Compiler Flags
--------------
- added --[no-]optimize-on-clauses and --optimize-on-clause-limit
Bug Fixes/New Semantic Checks (for old semantics)
-------------------------------------------------
- fixed a bug in which wide references weren't removed from local blocks
- fixed a bug in which range slicing resulted in divide-by-zero due to overflow
- fixed a bug in which Block misdistributed indices at sufficiently large sizes
- fixed a bug in which multirealm PVM runs could set up locales in wrong order
Error Message Improvements
--------------------------
- improved the error messages for failed pvm launches
Compiler Analysis and Optimizations/Performance of Generated Code
-----------------------------------------------------------------
- added an optimization to execute on-clauses using a remote locale's listener
(see --[no-]optimize-on-clauses and --optimize-on-clause-limit)
Internal
--------
- added initial support for recursive leader iterators
- added support for generating Chapel errors in terms of C line/file
- refactored and cleaned code in PVM launcher and comm layer (more remains)
- added Makefile.tau for experimental use of Chapel with Tau
============
version 1.01
============
Update to third public release of Chapel, October 30, 2009
(see also changes for version 1.0)
High-Level Themes
-----------------
- multi-locale task parallelism
- support for single- and multi-locale data parallelism
- improved scalability and stability
- prototype implementation of realms for hybrid computing in Chapel
(see doc/technotes/README.multirealm)
Packaging Changes
-----------------
- added a utility script, chpl-multirealm, to help with multi-realm compilation
- added PVM to the third-party directory to support multi-realm computation
Newly Implemented Features
--------------------------
- added support for multi-realm features to support heterogeneous computation
- extended replication of global constants to include record types
Platform-specific notes
-----------------------
- made XT GASNet compiles use "cc" without the full path discovered by GASNet
Documentation
-------------
- updated .emacs excerpts in etc/emacs/README to use more modern idioms
Example Codes
-------------
- added an example demonstrating multirealm computation features
- cleaned up RA to refer to TableDist in on-clauses rather than T.domain.dist
Standard Distributions
----------------------
- made the default distributions throttle parallelism based on #tasks running
- improved the Cyclic distribution to support strides and slicing
- added initial support for a "Private" distribution with one index per locale
Bug Fixes/New Semantic Checks (for old semantics)
-------------------------------------------------
- fixed a bug in which distributions deadlocked when numLocales > maxThreads
- fixed a bug with parallel iteration when problem size ~= #cores
- fixed some bugs with slicing and querying the length of degenerate ranges
- fixed some bugs in distributions when iterating over degenerate ranges
Compiler Analysis and Optimizations/Performance of Generated Code
-----------------------------------------------------------------
- reduced the number of communications required to set up distributions
- reduced the time required to set up Block distributions
- reduced the time required to create privatized data structures
- optimized iterators for Block- and Default-distributed Arithmetic arrays
- optimized the expression .locale.uid to avoid communication
- optimized .dist methods on default domains to return the private distribution
Testing system
--------------
- softened the signal used by our timeout script from -9 to -15
Internal
--------
- fixed some const char* issues in strstr, strchr, strrchr calls
- added verification that gotos are in same functions as their labels
===========
version 1.0
===========
Third public release of Chapel compiler, October 15, 2009
High-Level Themes
-----------------
- multi-locale task parallelism
- improved support for single- and multi-locale data parallelism
- improved stability and portability
- improved memory utilization of compiler-generated code
- target audience: general public
Environment Changes
-------------------
- added emacs/vim modes to release -- see $CHPL_HOME/etc/README
Changes to Chapel Language
--------------------------
- removed implicit coercions from primitive types to strings to avoid confusion
- a default array variable can now be made to alias another via the => operator
- accesses to variable x in module M using 'M.x' must now follow a 'use M'
Newly Implemented Features
--------------------------
- forall loops over ranges & arithmetic domains/arrays are now parallelized
- improved support for and correctness of record and class destructors
- array declaration+initialization syntax now results in parallel evaluation
e.g., var A: [i in D] real = foo(i); will be evaluated in parallel
- added == and != for imag and complex types; added >, >=, <, <= for imag types
Portability of code base
------------------------
- improved support for the Cray compiler on XT systems (cray-xt-cray)
- reduced warnings for gcc > 4.3
- improved portability with respect to Intel icc/icpc v11.x
- removed outdated assumptions about Sun compiler environments
- removed the makechpl script for Mac users because of portability issues
Platform-specific notes
-----------------------
- added a PBS launcher for the Cray CX1 named pbs-gasnetrun_ibv
Launcher-specific notes
-----------------------
- several improvements to the pbs launcher (see README.launcher/README.xt-cle)
- environment variables are now propagated to the application
- a queue can be specified via the CHPL_LAUNCHER_QUEUE environment variable
- a wallclock limit can be specified via CHPL_LAUNCHER_WALLTIME
- the NCCS pbs launcher no longer uses the debug queue by default
- added support for CHPL_LAUNCHER_SUFFIX to launch a file other than ..._real
Semantic Changes
----------------
- changed distributions from having class/reference semantics to value semantics
- made module initialization occur at program startup rather than use statements
- only modules specified on the command-line are candidates for the main module
- added support for returning locally scoped arrays from variable functions
- changed interpretation of method definitions on scalar types
e.g., 'def int.foo()' now defines foo() for default-sized ints, not all ints
Syntactic/Naming Changes
------------------------
- renamed MultiBlockDist.chpl to BlockDist.chpl
- removed the Block1D distribution since Block subsumed it
- added placeholder notation for creating new distribution values
e.g., new Block(...) => distributionValue(new Block(...))
- renamed the pbs launcher for Cray XT to pbs-aprun since it wraps both packages
Compiler Changes
----------------
- improved support for slicing [strided] domains/arrays with [strided] slices
- improved flushing of writeln() statements to the file being written to
- removed support for goto from the compiler's front-end
Runtime Library Changes
-----------------------
- improved pthread setup, termination, and cleanup for non-erroneous exits
- refactored threading runtime to support code reuse for pthread-like threads
- added support for memory tracking for multi-locale executions
Documentation
-------------
- improved the Types, Modules, and Ranges chapters of the language specification
- added mention of 'delete' to language specification
- improved the Label, Break, and Continue subsection of the language spec
- minor changes to other chapters of the language specification
- updated README.xt-cle and README.launcher to reflect new pbs features
- updated the various READMEs to reflect minor changes and wording
Example Codes
-------------
- changed fft to use a Block distribution
- changed reference to MultiBlockDist module in block2D.chpl to BlockDist
- changed distributions to use the placeholder value type notation
- changed default value of tasksPerLocale in HPCC benchmarks to avoid reductions
- changed RA's constant array m2 into a constant scalar for performance reasons
- changed follower iterator in ra-randstream.chpl to accept tuple of ranges
- deleted classes in example programs to reclaim memory
- increased problem size for reductions.chpl to avoid bug w/ 5+ cores per locale
Standard Modules
----------------
- added printMemStat() to the standard Memory module; improved printMemTable()
- added start/stopVerboseMem[Here]() to the Memory module for tracing memory use
- improved reference counting of domains and arrays
- removed the (undocumented) Schedules module
Standard Distributions
----------------------
- merged Block1D and Block since the latter subsumed the former
- removed the default rank of 1 for the Block distribution
- added support for a multidimensional target array of locales to Block
- improved support for strided domains/arrays in the Block distribution
- added support for slicing to the Block distribution
- added support for member(), order(), and position() to the Block distribution
- added initial support for a Cyclic distribution
- added very preliminary support for a Block-Cyclic distribution
- improved the support for the CSR distribution to match the default sparse case
- unified leader/follower iterators to always work on tuples of ranges
- removed subBlocks() from the standard distribution interface
Compiler Flags
--------------
- added support for a module path flag (-M) to search for modules via filenames
- added a flag to print the module search path (--print-search-dirs)
- added a flag to print module files being parsed (--print-module-files)
- added support for a -I flag to specify a search directory for C headers
Generated Code Flags
--------------------
- added support for specifying configuration variables/constants without =
e.g., you can now use './a.out --n 4' in addition to ./a.out --n=4'
- improved flags for tracking memory utilization (see README.executing)
- improved error messages to indicate the argument number
- made compiler-generated generic type names deterministic
- improved robustness of --numLocales flag
Bug Fixes/New Semantic Checks (for old semantics)
-------------------------------------------------
- added an error for using => on non-array types
- added an error for using (...x) on non-tuple types
- added a semantic check against tuples sized by 0 or a negative value
- made labels on statements other than serial loops be errors
- made break and continue only applicable within serial loops
- improved error checking when assigning between ranges of different boundedness
- fixed a bug in which breaks in serial loops gave errors in parallel contexts
- fixed a bug in which tuple copies sometimes aliased the original tuple
- fixed a bug in which generic fields were incorrectly aliased in constructors
- fixed a bug in which we were accidentally supporting illegal parameter casts
- fixed a bug in which string parameter members broke the compile
- fixed a bug in which indices were inadvertantly shared/non-local in promotions
- fixed a bug in which pbs launchers did not work with shell prompts ending in $
- fixed a bug in which the compiler attempted to clone external functions
- for Cray XT, fixed default setting of GASNET_MAX_SEGSIZE to specify size in KB
- fixed a race in the creation of private, replicated distribution classes
- fixed a bug in which tensor iteration resulted in internal errors
- removed a subtle race condition in program startup
- fixed a bug in which we called default constructrs by name
- fixed deletion of list elements in List module
- added support for generating the implicit Program module in --html view
Error Message Improvements
--------------------------
- fixed line numbers in errors involving dynamic dispatch and [con/de]structors
Compiler Analysis and Optimizations/Performance of Generated Code
-----------------------------------------------------------------
- vastly reduced amount of memory leaked due to compiler-allocated data
- improved performance of loops using Block distributions
- improved performance and reduced memory requirements for memory tracking
Cleanup of Generated Code
-------------------------
- embedded information about compilation options to the generated code
Testing system
--------------
- improved precedence of execution options specified via .execopts or EXECOPTS
- made parallel testint place -nl x flags at the end of the command line
- added support for PVM-based testing to the test script
Internal
--------
- replaced uses of "[unsigned] long long" with [u]int64_t for sane portability
- some unification of reserved names, though more remains
- improved Chapel's launcher runtime interface to be more general
- added a mechanism for intercepting printf/fprintf calls if required
- Makefile refactorings working toward supporting parallel make
- refactored runtime/mem- directories to decrease duplicated code
- renamed runtime files to improve standardization, though more remains
- removed linked list pointers from memory tracking table
- reduced amount of runtime code linked into the launcher binary
- made the use of chpl_globals_registry more consistent across locales
- relaxed compiler assumptions about classes with the "data class" pragma
- added support for generating type and offset information for communications
- some initial work toward supporting execution on heterogeneous architectures
- some initial work toward supporting CPU<->GPU computations in Chapel
- some initial work toward supporting profiling tools with Chapel
- removed "valid var" pragma
- made wrapper functions use blank intent rather than inheriting from wrappee
- changed strategy for determining when value types should be copied/destroyed
- made domain and array classes always have reindexed set to true by default
- added a developer flag for disabling compiler-introduced memory frees
- removed support for _init functions from the compiler
- removed assumptions that replicated global constants are stored symmetrically
- added thread cancel and join functions to the threading runtime interface
- added a type, chpl_threadID_t to pass thread IDs between C and Chapel
- changed point at which variables are put on the heap
- made all built-in modules be filename based
- refactored directory structure of $CHPL_HOME/modules into standard/internal...
- added optimizations to remove unnecessary autocopy/autodestroy calls
- improved robustness of internal modules that use standard ones
- changed the scan implementation to generate an array rather than a list
- changed array assignments to use array iteration rather than random access
- made --no-cpp-lines the default for -g for developers
- improved handling, robustness of built-in configuration variables
- split chpl_comm_md.h into two files to permit platform- and comm- overrides
===========
version 0.9
===========
Second public release of Chapel compiler, April 16, 2009
High-Level Themes
-----------------
- multi-locale task parallelism
- very initial/limited support for data parallelism, distributed arrays
- improved stability, portability, and performance
- target audience: general public
Environment Changes
-------------------
- added a script to print out set and inferred CHPL env vars
(see util/printchplenv.pl)
- added support for the IBM xlc/xlC compilers by setting CHPL_*_COMPILER to ibm
- added an environment variable for naming a queue for the PBS launcher
(see doc/platforms/README.xt-cle)
- added an environment variable for specifying #cores/locale to pbs/aprun
(see doc/platforms/README.xt-cle)
- improved the logic for inferring host and target compilers for xt-cle
Changes to Chapel Language
--------------------------
- added a typeToString() function for converting a static type into a string
Newly Implemented Features
--------------------------
- added queries for task/thread counts per locale for CHPL_THREADS=pthreads
(see doc/README.threads)
- added a printMemTable() routine to the Memory module for use in Chapel
(see doc/README.executing)
- added a prototype multidimensional Block distribution: MultiBlockDist.chpl
(see examples/tutorials/block2D.chpl)
Portability of code base
------------------------
- improved our general method of building and using GASNet for portability
- improved portability of GASNet configure + build steps for xt-cle
- improved the heuristic for setting GASNET_MAX_SEGSIZE for xt-cle
(see doc/platforms/README.xt-cle)
- added initial support for IBM Power5 and Power6 systems
(see doc/platforms/README.ibm)
- made flex and bison generate .cpp files rather than .c files for portability
- added capabilities to build Chapel on Macs using xcodebuild
(see doc/platforms/README.macosx)
- added a -d option to our use of aprun in the aprun and pbs launchers
- removed the assumption that function pointers are identical between nodes
Syntactic/Naming Changes
------------------------
- disallowed identifiers that start with $
- removed compilerError and compilerWarning as keywords
- permitted binary and hex literals to be written using uppercase B/X
- renamed classes used for defining distributions
Runtime Library Changes
-----------------------
- added support for communication diagnostics and debugging
(see doc/technotes/README.comm-diagnostics)
Documentation
-------------
- added a new ACKNOWLEDGEMENTS file for financial and machine time support
- refactored the doc directory, pushing platform & technical notes into subdirs
- minor changes and improvements to the language specification
- minor edits to many of the README files
- updated the man page
Example Codes
-------------
- pushed most top-level examples into tutorials/ and programs/ subdirectories
- added new tutorial examples for variables, ranges, classes, generic classes
- added new tutorial examples for timers and the prototype Block distribution
- changed quicksort to ensure levels beyond thresh do not re-enable parallelism
Compiler Flags
--------------
- added a flag to disable/enable the remote value forwarding optimization
Bug Fixes/New Semantic Checks (for old semantics)
-------------------------------------------------
- fixed a number of spurious errors caused by how we were using GASNet
- fixed problems in how we terminated multithreaded GASNet programs
- added the ability for _chpl_comm_fork[_nb] to handle large arguments
- applied a GASNet patch that fixes an x86 alignment error
- fixed a bug which had previously limited execution to 1024 locales
- fixed a bug in which arrays could only store 2**31 elements
- eliminated a race condition when two tasks initialize the same module
- fixed a bug in which integer exponentiation was being computed using pow()
- fixed a bug in which slicing via .. could only be done for int(32) indices
- fixed a bug with Block1D domains that exceed the bounding box argument
- added a check to ensure that return statements are not used at module scope
- improved verification of formal/actual argument types
- fixed a bug in which long program names broke the PBS launcher
- fixed a bug with incorrectly spacing operators in generated code
- fixed Chapel error messages that referred to C's errno variable
- fixed a bug with accidentally shared state during parallel iterations
- fixed a bug related to reductions involving forall expressions
Error Message Improvements
--------------------------
- added a runtime error message if the launcher binary can't find the _real one
Compiler Analysis and Optimizations/Performance of Generated Code
-----------------------------------------------------------------
- improved the correctness and effectiveness of remote value forwarding
- optimized performance of local communications
- optimized parallel iteration for Block1D to minimize remote references
- parallelized declarations of Block1D distributions, domains, and arrays
- optimized implementation of broadcasts used to initialize private data
- optimized away a thread per locale used for progress+termination
- improved reclamation of compiler-allocated memory
- improved the correctness and effectiveness of re-privatization optimizations
- privatized the default distribution object
- removed array/domain wrapper records
Compiler Performance and Cleanup
--------------------------------
- removed hand-baked and occasionally incorrect integer types int32, int64
- fixed an infinite loop when inlining recursive iterators
- fixed cases in which compiler temps were used outside the variable's scope
Cleanup of Generated Code
-------------------------
- removed redundant reference types from the generated code
Internal
--------
- switched iterator implementation to use records rather than classes
- improved the naming of identifiers in the runtime and generated code
- removed compiler support for (undocumented) anonymous record types
===========
version 0.8
===========
First public release of Chapel compiler, November 14, 2008
High-Level Themes
-----------------
- multi-locale task parallelism
- improved task parallel correctness, features, thread management
- improved stability of core features
- very initial/limited support for data parallelism, distributed arrays
- target audience: general public
License Changes
---------------
- switched from MIT to BSD license (see LICENSE)
- updated user agreement text (see AGREEMENT)
Environment Changes
-------------------
- changed the identifier for the Cray XT platform from xt-cnl to xt-cle
- added a CHPL_MEM setting to select memory allocators (see README.chplenv)
Changes to Chapel Language
--------------------------
- changed operator precedence for : vs. **, bitwise ops, reduce, !, unary +/-
- added destructors and a 'delete' keyword for destroying class instances
- removed open interval syntax in which [0..n) == 0..n-1
- added range operator # that counts a number of elements
e.g., 0..#n == 0..n-1; 0.. by 2 #5 == 0, 2, 4, 6, 8
- added support for locale.name to query a locale's node name
- added support for overriding iterators within a class hierarchy
- added the capability to declare generic formals for gen. classes with defaults
e.g., "x: range" expects a default range; "x: range(?)" expects a generic one
- added the ability to query argument types without naming the queried type
e.g., "x: ?" rather than "x:?t"
- added support for +/- on (arith. domain, index) and + on (index, arith. domain)
- removed support for * and / on (range, integer) and - on (integer, range)
- added support for .clear() on arithmetic domain vars to reset to degenerate
- added .order() and .position() methods to ranges and domains
e.g., (1..3).order(3) == 2; ([1..3, 1..3]).position((2,1)) = (1,0)
- added support for variable-width boolean types
- added support for ~ on bool types
- initial support for a local block that asserts code requiring no communications
e.g., on Locale(1) { const x: int; local { x = x + 1 } }
- added initial support for leader/follower iterators supporting zippered foralls
- added initial support for distributed domains and arrays using a Block1d class
- added initial support for parallel reductions and forall expressions
Newly Implemented Features
--------------------------
- added support for tuples of lvalues
e.g., "for (a,b) in (A,B)" where A and B are arrays
- array initializer expressions can now be used for array class members
- added support for user-defined constructors for generic classes
- added support for overriding methods using subtype return types
- added support for querying the eltType of an array
e.g., def foo(A: [D] ?t) { ... }
- added support for .remove() on opaque domains
- added support for explicitly naming a function's module at the callsite
- added support for freeing compiler-introduced heap-allocated variables
- added initial support for freeing value type memory (records, arrays, domains)
Portability of code base
------------------------
- added support for the Cray CX1 platform running Linux (see README.cx1-linux)
- improved level of support for the Cray XT platform (see README.xt-cle)
Semantic Changes
----------------
- disallowed calling a method on a nil reference as previously permitted
- changed the instantiation point for dynamically-dispatched methods
- permitted partially-bounded out-of-bounds degenerate ranges to be legal, empty
e.g., var A: [1..10] real; A[11..] == A[11..10] == a legal, empty slice of A
- on clauses are now evaluated for side effects when using the --local flag
- made single-statement sync statements create a new scope
- added support for param string comparisons, concatenation, and other ops
- added support for casting an integer to a string at compile time
- made the implicit 'setter' argument in var functions constant and foldable
Syntactic/Naming Changes
------------------------
- all non-compound single-statement conditionals/loops now require then/do
- functions now require a block statement unless they only contain a return stmt
- added support for a single-statement serial statement
e.g., "serial test { foo(); }" => "serial test do foo();"
- removed "opaque" from the list of reserved words--it is now a type like "int"
- 'distributed' clauses no longer require parenthesis
Compiler Changes
----------------
- the compiler now requires CHPL_HOME to be set
- added support for opaque types for use when interfacing with extern functions
Third Party Changes
-------------------
- updated GASNet version to GASNet 1.12.0
- added support for using dlmalloc as a memory allocator
Runtime Library Changes
-----------------------
- all tasks in a cobegin are now set up before any start executing for pthreads
- made the task that starts a cobegin/coforall help execute the component tasks
- made the task that enters a sync statement help execute the component tasks
- added "launcher" capability to wrap job launch mechanism (see README.launcher)
- improved the thread-safety of declaring arrays over a domain
Documentation
-------------
- improved the --help descriptions of --[no-] flags
- updated and improved the language specification
- improved the specification of instantiated fns: visibility & point-of-inst.
- updated the various README files
- updated the man page
Example Codes
-------------
- added a hello-multiloc example to run a "Hello, world!" on multiple locales
- improved hpcc codes from our 2008 HPC Challenge entry and added HPL (hpl.chpl)
- made the stream.chpl and ra.chpl benchmarks use Block1D-distributed domains
- added support for the stream and ra benchmarks to use multiple tasks per locale
- improved the verification step of stream.chpl to make it stronger
- improved the taskParallel example to reduce the likelihood of races
Standard Modules
----------------
- added a Norm module for computing vector and matrix norms
- added a Containers module for standard container classes
- added a day of week enumeration and getCurrentDayOfWeek() to the Time module
- fillRandom() calls in the Random module now fill Block1D arrays in parallel
Compiler Flags
--------------
- improved the parsing of single-dash compiler flags to avoid common errors
e.g., -abcd != -a -b -c -d; -hepl != -h -e -p -l
- renamed --no-expand-iterators-inline-opt to --[no-]inline-iterators
- renamed --no-single-loop-iterator-opt to --[no-]optimize-loop-iterators
- removed the --chplhome flag
- removed the --flow-analysis flag
- made all optimization control flags into --[no-] flags
- added --[no-]dead-code-elimination to turn dead-code elimination off/on
- added --[no-]live-analysis to turn live variable analysis off/on
Generated Code Flags
--------------------
- added a -b/--blockreport flag to help debug deadlocked 1-locale programs
- added a -t/--taskreport flag to print a list of tasks for 1-locale programs
- made the -v flag print node names for locales on which code is executing
- made the -v flag print the commands used by the launcher
Bug Fixes/New Semantic Checks (for old semantics)
-------------------------------------------------
- fixed some subtle race conditions in the pthreads version of the runtime
- fixed a bug in which write statements would not print atomically as intended
- fixed a bug in which multidimensional tuple-to-array assignment was failing
- fixed support for readXX() on single variables
- added some runtime checks to try and avoid integer wraparound in malloc sizes
- improved support for range slicing at extreme integer values
- made 1-tuple-style declarations illegal: var (x) = ...;
- fixed a number of bugs related to generic function instantiation points
- fixed a bug in which casts on return expressions were ignored
- fixed a bug related to iterating over a single iterator class multiple times
- fixed a bug in which param functions with multiple returns corrupted constants
Error Message Improvements
--------------------------
- improved an error message related to illegal assignments of domains to arrays
- added an error check to prevent iteration over a type
- improved error messages related to bad tuple index types
- improved error messages related to iterators and promoted expressions
- added a warning about cobegin statements with fewer than two statements
Compiler Analysis and Optimizations/Performance of Generated Code
-----------------------------------------------------------------
- made "here" into a per-locale variable, reducing communication
- optimized read-only non-local accesses to value types
- added initial support for privatizing global domain/array descriptors
- added initial support for optimizing zippered iteration over aligned arrays
- optimized coforall...on and begin...on idioms to reduce thread requirements
- added reference counting to domain classes to aid in freeing them
Compiler Performance and Cleanup
--------------------------------
- rewrote the compiler's symboltable
- added support for a BitVec class to save space and time
- tightened up memory leaks in the compiler
- specialized parameter tuple indexing for performance and fewer special cases
- reimplemented the IR traversal mechanism
- removed def/use information from the Symbol class to save space
- removed filename references from IR nodes to save space
- removed unused fields from internal classes
- reimplemented the caching data structures used in function resolution
- streamlined function instantiation when a function is not a viable candidate
- refactored and cleaned up the wrapper/generic function caching code
- applied reference propagation to functions just prior to inlining
- moved the prune pass prior to optimizations to save time
- optimized the verification pass by hoisting out back pointer checks
- optimized reference propagation to build smaller use/def sets
- optimized the scalar replacement pass to localize the iterative aspects
- improved the set of live references added/omitted from iterator classes
- eliminated lots of dead code
Testing System
--------------
- made the test system execute .numlocales tests on 1 locale for CHPL_COMM=none
- made the testing system set the CHPL_* environment variables if they aren't
- made the test system generate its output using relative paths
- fixed a bug in the testing system's "skipif" capability
Internal
--------
- added support for dynamically turning on/off communication and memory tracing
- improved debug output for the gasnet communication layer
- reorganized abstract distribution, domain, array classes
- generalized creation of runtime types
- renamed SingleLocale* classes for domains/arrays to Default* classes
- removed need for buildEmptyDomain methods within domain classes
- removed redundant type/param fields from array wrapper records
- simplified the AList class
- revamped implementation of pragmas and unified with various boolean flags
- added a --runtime flag to compile Chapel code into the runtime and used it
- removed --nostdincs developer compiler flag
- improved the format of the --print-statistics flag and added summary info
- made the --baseline flag into an aggregate flag
- fixed a bug with the --gdb flag in which quit and run would fail after errors
- improved the cleanup of temporary files when using the --gdb flag for gdb >6.6
- added support for developers to print references in 0x0000abcd form
- added a rootModule that contains the program module but is not codegen'd
- decoupled the visible functions data structure from the symbol table
- removed the need for the symboltable after scope resolution
- changed module representation of CHPL_* variables from enums to strings
- added support for compiler CHPL_* variables of type const char*
- added an internal traceback capability to unravel inlined functions
- changed the mechanism for specifying reserved symbol names needing mangling
- refactored reference propagation to share code with scalar replacement
- added debugging functionality to the scalar replacement pass
- replaced compute_sym_uses() with buildDefUseMaps() and for_defs/uses macros
- simplified and optimized the normalize pass
- removed the def/use map in function resolution
- added a promotion wrappers cache to avoid creating duplicate wrappers
- general cleanup of coercion wrapper code
- refactored instantiation code
- changed handling of on, begin, cobegin, coforall to use blocks, not nested fns
- reimplemented heap allocated variables
- changed arithmetic array of primes into function returning primes
- made all exits from the compiler use our clean exit routine
===========
version 0.7
===========
Fourth preliminary release of Chapel Compiler, March 31, 2008
High-Level Themes
-----------------
- multi-locale task parallelism
- improved task parallel correctness, features, thread management
- improved stability of core features
- target audience: HPCS mission partners, select HPC/academic/industry users
Changes to Chapel Language
--------------------------
- added "new" keyword to invoke class/record constructors
e.g., "class C { ... } var myC = C(...);" => "... var myC = new C(...);"
- enumerated types now require the type to be named before a component symbol
e.g., "enum myEnum {A, B, C}; var x = B;" => "... var x = myEnum.B;"
- changed a file's mode from a string to an enumeration
e.g., file(..., "r") => file(..., FileAccessMode.read)
- added "sync" statement to join dynamic parallelism
e.g., sync { /* create parallelism */ } // waits here for parallelism to end
- added "here" constant to refer to the locale on which a task is executing
- added support for readXX and isFull on single variables
- added support for functions with type varargs
e.g., def foo(type t ...?numTypes) { ... }
- added support for vararg read()/readln() functions that return a tuple value
e.g., "read(int, float, string);" returns an (int, float, string) value
- added a sorted() iterator to associative domains/arrays and opaque arrays
e.g., var table: domain(string); ... for entry in table.sorted() do ...
- added support for a compilerWarning() call similar to compilerError()
e.g., compilerWarning("I didn't expect this function to be called");
- added string relational operators
e.g., ..."hi" >= "bye"...
- removed the "of" keyword
- removed the "ordered" keyword and concept
Newly Implemented Features
--------------------------
- execution using multiple locales (see: doc/README.multilocale)
- use of on clauses taking locale/lvalue expressions to generate remote tasks
e.g., "on Locales(i) do ...", "var x = ...; ... on x do ..."
- use of <expression>.locale to query the locale on which an lvalue lives
e.g., "var x = ...; ... x.locale ..."
- task pool to support the creation of more tasks than executing threads
(see doc/README.threads for more details)
- added support for calling methods within class constructors
- improved support for member initializer expressions within classes
- strengthened distinction between type specifiers and constructor calls
- temporarily removed support for real(128), imag(128), complex(256)
- enumerated and opaque arrays now support iteration
- added support for tuples of sync variables
- added support for declaring enumerations within classes
Portability of code base
------------------------
- removed a number of warnings specific to particular compilers/platforms
Semantic Changes
----------------
- in a type context, (int) is no longer a 1-tuple of type int; use 1*int instead
- Chapel now parses types in the same way that it parses general expressions
Syntactic/Naming Changes
------------------------
- renamed opaque domain's .new() method to .create()
- renamed the (undocumented) Locales domain from LocalesDomain to LocaleSpace
Documentation
-------------
- new README files in the doc/ directory
- README.multilocale file explains how to execute using multiple locales
- README.threads explains how tasks are implemented using threads
- language specification revisions
- greatly improved the "Parallelism and Synchronization" chapter
- greatly improved the "Locality and Distribution" chapter
- made other updates to reflect other changes mentioned in this file
- removed most of the language overview section, believing it needs updating
- updated the quick reference document to include locality concepts
- updated HPCC documents to reflect "new" keyword and enumerated type qualifiers
- generally refreshed the README, CHANGES, STATUS files
Example Codes
-------------
- added new example codes
- multilocale.chpl to serve as a multi-locale execution tutorial
- taskParallel.chpl to serve as an introduction to task-parallel concepts
- varargs.chpl to demonstrate the user of variable argument functions
- updated existing examples to reflect language changes
- added "new" keyword to tests that create class instances
- for tests that use files, changed access mode from string to enum
- added enumeration type qualifiers to uses of enumerated types
- changed opaque.chpl test to rename the opaque domain .create() method
- changed blockLU's input data to improve stability across compilers
- made automated testing of opaque.chpl deterministic
Standard Modules
----------------
- added a skipToNth() method to the RandomStream class
Compiler Flags
--------------
- changed flags to have a --no-... variation (see chpl man page for details)
--local => --[no-]local where the default is based on CHPL_COMM
--serial => --[no-]serial where the default is based on CHPL_THREADS
- added new flags (see chpl man page for details)
--[no-]ieee-float controls the strictness of IEEE floating point operations
--fast flag turns on optimizations & disables runtime checks and IEEE floats
--explain-instantiation describes the instantations of functions/types
Generated Code Flags
--------------------
- added a config const "maxThreads" to limit the number of threads per locale
(see doc/README.threads for more information)
- made --help flag list built-in config consts/vars (numLocales, maxThreads)
- added a --quiet/-q flag to suppress runtime warnings
Bug Fixes/New Semantic Checks (for old semantics)
-------------------------------------------------
- fixed support for arrays of arrays and arrays of syncs within classes
- fixed several bugs in the implementation of associative/opaque domains/arrays
- improved composability of forall expressions and coforall statements
- improved checks preventing the use of types in value contexts and vice-versa
- added checks for illegal control flow within parallel/sync/on statements
- added warning if locale is applied to an expression known to be local
- added a runtime warning when using distributions on more than 1 locale
- removed incorrect copies that were inserted for certain default argument types
- fixed ability to specify C source files with paths
- fixed a bug in which standalone reads of sync vars did not consume full/empty
e.g., "myflag$;" is now equivalent to "myflag$.readFE();"
- fixed a bug in the implementation of .length for degenerate ranges
- ensured user cannot create new locales
- prevented user from being able to modify a locale's id
- removed instantiation limit error messages generated by tuples
- fixed a bug with the --cpp-line flag for long generated C lines
Error Message Improvements
--------------------------
- improved error messages for generic type specifiers
Compiler Analysis and Optimizations/Performance of Generated Code
-----------------------------------------------------------------
(no significant ones in this release)
Compiler Performance and Cleanup
--------------------------------
- reduced memory footprint of certain compiler IR classes
Generated Code
--------------
- changed implementation of subclasses
- added support for remote references and remote classes
- improved line number reporting for certain functions
- renamed some identifiers to avoid initial underscores -- more remain
- improved name mangling policy
- changed integer type aliases to use stdint.h types
- turned up C compilation warning levels for developers
Testing System
--------------
- added support for listing any number of tests and directories on command-line
- removed -onetest and -startdir flags due to above support
- allowed start_test to be run from any directory
- removed support for Makefile-driven testing
- removed start_clean script
- added "skipif" support for skipping a test or directory based on env vars
Internal
--------
- unified implementation of cobegin/coforall to use begins
- use endCounts to implement cobegins/coforalls rather than syncStacks
- improved runtime TAGS file and added TAGS file for generated code
- improved unification/normalization of AST classes and primitives
- removed unnecessary primitives, types, symbols
- changed places in code where pragmas can occur
- converted from CVS to SVN
- made --ccwarnings into --[no-]ccwarnings where the default is based on --devel
===========
version 0.6
===========
Third preliminary release of Chapel Compiler, December 21, 2007
High-Level Themes
-----------------
- single-locale, multiple threads
- improved stability of core features
- support for additional serial features
- improved single-threaded performance and memory utilization of generated code
- improved multi-threaded correctness, features
- improved compiler performance and memory utilization
- improved portability of compiler/runtime code and generated code
- support for cross-compilation environments
- target audience: HPCS mission partners, select HPC users and centers
Changes to Chapel Language
--------------------------
- added support for defining type functions
e.g., def myint(param x: bool) type { return if x then int(32) else int(64);}
- changed routines supported on sync/single variables and made them methods
e.g., var x: sync int; x.writeXF(2); if (x.isFull) { ... }
- added support for expression-level for and forall loops using keyword syntax
e.g., var A: [D] int = for i in D do foo(i);
- added support for readln() function which skips to EOL after reading its args
- added support for a main() function per module, resolvable via --main-module
- added support for translate, interior, exterior, and expand methods on ranges
- added support for membership test on ranges
e.g., var r: range = ...; if (r.member(3)) { ... }
- added support for range/scalar arithmetic using +, -, *, /
e.g., (1..10) + 1 == 2..11; (1..10) * 2 == 2..20 by 2
- removed support for operations between scalars and tuples
e.g., (1, 2) + 3 is no longer supported; (1, 2) + (3, 4) still is
- added support for bitwise operators on int/uint pairs of the same size
e.g., int(32) & uint(32) => uint(32)
Newly Implemented Features
--------------------------
- added support for arrays of arrays whose inner arrays are of uniform size
- added support for arrays of domains
- added support for instantiating types/functions using array types
e.g., class C { type t; ... } type vect = [1..n] int; var myC: C(vect);
- implemented a reshape function for arrays
- initial implementation of opaque domains and arrays
- added support for slicing using unbounded and degenerate ranges
e.g., for A: [1..n, 1..n] real, A[2.., ..] is equivalent to A[2..n, 1..n]
- added support for rank change slicing of domains and arrays
e.g., var V: [1..n] int; V = A[n/2 + 1, 1..n];
- relaxed requirements that slicer and slicee objects use the same integer type
- added support for | and & reductions over boolean aggregates
- added support for a clear() method on associative domains
- preliminary support for "on" statements with restricted functionality
- improved support for user-defined class constructors
- added support for runtime checks against nil class references
e.g., class C { ... } var myC: C; C.foo(); generates a nice error
- improved support for nested modules
- improved symbol resolution for external modules
- implicit enum-to-string coercions and explicit string-to-enum conversions
- initial support for controlling type-to-string formatting (doc/README.format)
- initial support for prototyping and calling extern C functions from Chapel
(see doc/README.extern for more details)
- added support for generic function arguments of sync types
e.g., def foo(x: sync) { ... }
- improved support for garbage collection in single-threaded codes (see STATUS)
- improved tuple type orthogonality; they can now be used in most type contexts
- added support for strided param for loops
Portability of code base
------------------------
- added support for compiling with Intel, PGI, Pathscale, and Cray compilers
- added initial support for compiling for Cray MTA/XMT, X1s, and XTs
- improved portability of source and generated codes across compilers/platforms
- refactored Makefiles to better separate compiler settings from platforms
- added support for cross-compilation environments -- see doc/README.chplenv
- added mechanisms for selecting threading/communication libraries -- see "
- added native support for task parallelism on Cray MTA/XMT platforms
Semantic Changes
----------------
- removed implicit coercions from integer types to real(32)
- made queries of an array's domain via A.domain or A:[?D] constant
- removed dynamic dispatch on method calls with no parenthesis
- user-defined constructors now squelch the creation of a default constructor
- redefined range and domain slicing to use intersection semantics
- changed location of instantiated generics to be their definition point
- defined semantics of default functions as being "return a const"
- function resolution now favors non-promoted functions as a tie-breaker
- better defined casts between complex, imaginary, real, and integral types
Syntactic/Naming Changes
------------------------
- added support for $ in identifier names; used by convention to identify syncs
- allow floating point literals with an exponent to use an integral base
e.g., can now write 1e4 rather than 1.0e4
- changed locale array name from Locale to Locales (as described in spec)
- added ability to tag a function as returning a const value for documentation
Documentation
-------------
- updates to the language specification
- updated CHANGES and STATUS files
- refreshed READMEs
- updated compiler man page and --help message
- added AGREEMENT file listing user agreement
- refreshed and refactored CONTRIBUTORS file
Example Codes
-------------
- added tutorial example for using arithmetic arrays (arrays.chpl)
- added tutorial example for using opaque arrays (opaque.chpl)
- converted all HPCC example codes to use 64-bit indices for their domains
- fixed a bug in the HPCC FFT calculation of GFlop/s
- renamed sync vars to use $ naming convention
Standard Modules
----------------
- added support for 32-bit math routines
Compiler Flags
--------------
- added new flags:
--help-env : prints environment variables for each compiler flag
--help-settings : prints current setting of each compiler flag
--no-nil-checks : disables runtime checks for nil class references
--no-checks : disables all runtime checks (currently nil & bounds checks)
--main-module : selects between multiple possible program entry points
--ldflags : supplies flags for the C link step
--serial : disables all parallelism in a program
--local : optimizes compilation for single-locale execution
--no-scalar-replacement : disables the scalar replacement optimization
--short-names : generates the C code using short variable names (T<#>)
--make : specifies the GNU-compatible make utility used by the back-end
- removed flags:
--parallel : became the default and was redundant with --serial
- added ability to specify .c, .o, and .h files for interfacing to C routines
- improved error-reporting for incorrect compiler flags
- compiler now parses all flags before any significant ones are acted upon
- better error checking for parsing config param values
Generated Code Flags
--------------------
- added new flags:
-nl #/--numLocales=# flags for specifying the number of locales to use
-v/--verbose flags for increasing the verbosity of the generated code
- improved error-reporting for incorrect flags
- improved parsing of config const/var values
Bug Fixes/New Semantic Checks (for old semantics)
-------------------------------------------------
- whole-array assignment of arrays of sync variables now works correctly
- += and -= are now supported on sync variables
- fixed bugs in sync variable read/write functions
- added checks for blocking sync var reads/writes when $CHPL_THREADS == none
- fixed associative domain/array bugs caused by removing indices
- added bounds checking for associative domain/array operations
- improved bounds checking for array slicing
- bounds checking for string.substring() arguments
- improved legality checks for string-to-value conversions
- added legal-value checking for casts from integers to enumerated types
- improved robustness of tensor function promotion
e.g., exp[A, B] where A and B are arrays
- improved checks preventing against assignment to const variables
- added check that actual arguments to inout or out formals are valid lvalues
- added check against returning constants from var functions
- added checks against assigning to consts and params
- fixed use of inout and out intents with variable-length argument lists
- default argument values specified using a function call now work properly
e.g., def foo(x = bar()) ...
- improved handling of unifying multiple returns from a single function
- improved checking that a function returns a value along all control paths
- return statements are now supported in type select statements
- type checking of LHS and RHS on op= assignments
- added ability for user to overload operators for uint(64)/int combinations
- improved error checks for the use of values in a type context and vice-versa
- support for overriding this() method in subclasses
- improved error checks for legal expressions to iterate over
- added semantic check for degenerate rank-change slicing
Error Message Improvements
--------------------------
- added filename/line# information to many error messages
- improved notation for types in error messages from ": t" to "type t"
- added warning when C-style ++ or -- are used; these are duplicated unary ops
- improved clarity of function prototypes in function resolution errors
- improved clarity of error for creating a domain with mixed integral types
Compiler Analysis and Optimizations/Performance of Generated Code
-----------------------------------------------------------------
- improved performance for codes using type "complex"
- removed extraneous threads created by uses of the begin statement
- improved the performance of the bitMatMultOr routine in the BitOps module
- added strength reduction for ** with an exponent of 0-6 or 8
- added strength reduction for certain comparisons between uints and 0
Compiler Performance and Cleanup
--------------------------------
- improved performance of scalar replacement, copy propagation passes
- improved performance of compiling codes using type "complex"
- reduced memory requirements of compiler
Generated Code
--------------
- added support for generating code using short variable names (--short-names)
Testing System
--------------
- added support for Makefile-driven testing within a subdirectory
- added support for testing on multiple locales
- added support for "compilation only" testing to avoid running executables
- added support for the ability to specify a launch command to begin execution
- added the ability to suppress tests that are expected to fail
- added support for communication-layer-specific .good files
Internal
--------
- support for array type descriptor at runtime
- many refactorings and improvements to the compiler and runtime sources
===========
version 0.5
===========
Second preliminary release of Chapel Compiler, June 29, 2007
High-Level Themes
-----------------
- single-locale, multiple threads
- support for additional serial features
- improved single-threaded performance, memory utilization
- improved multi-threaded correctness, features
- target audience: HPLS evaluation team, HPCS mission partners,
select HPC users and centers
Changes to Chapel Language
--------------------------
- eliminated Chapel's sequence type
- in the future, a standard List library will provide similar functionality
- removed # and #= operators, since they were designed for sequences
- removed support for sequence literals; use tuple syntax instead
e.g., var A: [1..3] real = (0.1, 2.3, 4.5);
- removed support for casting sequences to tuples and tuples to sequences
- iterators in an expression context now result in a 1D, 1-based array
e.g., "iterator foo() {...} var A = foo();" creates a 1D array over [1..]
- added "range" type to language to replace old "arithmetic sequence" concept
e.g., "lo..hi" or "lo..hi by str" are ranges
- open interval syntax supported for ranges
e.g., "[lo..hi)" is equivalent to lo..hi-1
- +, -, *, / operators supported for range/scalar combinations
- added coforall loop construct for expressing explicit task parallelism
e.g., "coforall 1..4 do ..." will create four explicit tasks
- removed "iterator" keyowrd -- iterators are now functions that contain yields
- added support for defining a default ("these") iterator for classes/records
- added support for creating array aliases
e.g., "var Amid => A[2..n-1, 2..n-1];" creates an alias, Amid, to the slice
- support for standard math, bitwise, and comparison operators for tuples
e.g., "(i,j) + (1,-1)" yields "(i+1, j-1)"
- added a swap operator: <=>
e.g., "a <=> b" is semantically equivalent to "const t = b; b = a; a = t;"
- better support for writing output
- enabled support for writing to strings using a write() method
e.g., var s: string; s.write("x is: ", x);
- added a Writer class that enables user classes to be written to
- added writeThis() method to specify how a type should be output to a Writer
- added minloc and maxloc reductions that return min/max value and index
e.g., var (minVal, minInd) = minloc reduce (A, A.domain);
- changed arithmetic domain range access from D(<dim#>) to D.dim(<dim#>)
e.g., var rows = D.dim(1);
- arithmetic domains and arrays support low and high methods that return bounds
e.g., var loInd = A.low;
- support for range, domain, and array slicing via bounded or unbounded ranges
e.g., "A[2.., ..n]" is equivalent to "A[2..A.dim(1).high, A.dim(2).low..n]"
- support for promoting casts across array elements
e.g., var x: [1..4] real, y: [1..4] int; y = x:int;
- added support for param functions that support compile-time evaluation
e.g., "def square(param x) param { return x**2; } param n2 = square(14);"
- support for default values for param members of classes
e.g., class C { param bitWidth = 32; ... }
- support for top-level 0-argument functions without parentheses
e.g., def f { writeln("In function f"); }
- allow "main" function to be declared with or without parentheses
e.g., def main { writeln("Program will start here"); ... }
- allow "<index> in" to be elided in for/forall loops/expressions
e.g., "for 1..n { ... }", "var A = [1..n] 0.0;"
- support for multiple modules to be listed within a single "use" statement
- added support for reading a value of a specified type from a file
e.g., "var myint = infile.read(int);"
Newly Implemented Features
--------------------------
- support for sparse domains/arrays
- assignment of aggregate index expressions to sparse domains
- accumulation of indices into sparse domains using +=
- re-assignment of a sparse array's "zero" value using the .IRV field
- clear() method for emptying a sparse domain's index set
- arrays of sync variables are now supported
- added support for partially and fully unbounded ranges ("lo..", "..hi", "..")
- enumerated domains and arrays
- support for a numCores() function on the locale type to query # of cores
- subBlocks iterator on domains now generates a sub-block per processor core
- support for nested classes, records, and iterators
- serial statement
- added support for using "_" to ignore elements during tuple destructuring
e.g., var t: (int, real) = ...; (t1, _) = t;
- added support for nested tuple destructuring in variable decls/formal args
- support for config params of primitive and enumerated types
- initial support for accessing a module's members via modname.membername
- implemented dynamic casts between class types
- added initial support for copy collection-based garbage collection
- subdomain keyword is now supported, though subset relationship is not checked
- initial support for specifying a distribution class; interface still in flux
Syntactic/Naming Changes
------------------------
- removed support for using "?" in identifier names
- changed standard method member? to member
- changed standard method true? to isTrue
- removed support for "--" as a single-line comment style; use "//"
- an array's domain should now be accessed via A.domain rather than A.dom
- array element type identifier changed from elt_type to eltType
- made file open/close methods take parenthesis
- renamed "indefinite domains/arrays" to "associative domains/arrays"
Semantic Changes
----------------
- changed relative precedence of casts and unary +/- (unary +/- is now tighter)
e.g., -2:uint(32) is equivalent to (-2):uint(32) rather than -(2:uint(32))
- for/forall loops over arrays now result in references to elements, not copies
e.g., "for e in A do e = 0;" could be used to zero out an array
- enumerated types now start counting at "1" rather than "0" by default
- conditional expressions are no longer valid l-values
- improved semantics of module use transitivity, nested modules
- removed support for structural iterator interface (getHeadCursor, etc.)
- nested classes can refer to their outer class using the identifier "outer"
- initial support for querying parameters/types in a formal class argument
- similar support for variable-length argument lists of generics
- where clauses can now compare against formal generic types
- short-circuiting operators only require isTrue rather than true? & false?
- in x op=y, a cast to x.type is used in assigning back to x if it is primitive
- compilerError() can now take multiple arguments like a halt()
- replaced setter/getter functions with richer support for var functions
Documentation
-------------
- added man page for Chapel compiler (chpl)
- added CHANGES file
- added Quick Reference document
- added language overview chapter to the specification
- updated HPCC tutorial document and broke into two docs: overview and tutorial
- updated STATUS file
- cleaned up README files a bit
Example Codes
-------------
- added README.features file to map Chapel features to examples that use them
- several improvements to the HPCC benchmarks due to bug fixes, new features
- added several new examples:
- iterators example to demonstrate use of iterators
- linkedList example for nested, generic, iteratable, printable classes
- parallelQuickSort example to demonstrate serial/cobegin statements
- blockLU example to demonstrate domain slicing, array aliases, swap
- sparse example to demonstrate sparse domains and arrays
- slices example to demonstrate array slicing and reindexing
- reductions example to demonstrate minloc/maxloc reductions
- fileIO example to demonstrate simple use of file I/O
- rewrote the producer-consumer example to use a buffer of sync variables
- added a hello-module example to demonstrate simple Chapel program structure
- improved the comments for several tests
- removed stream-nopromote.chpl example, which had become redundant
- combined the two genericStack examples into a single file
- added performance testing support for stream.chpl and ra.chpl
Standard Modules
----------------
- Search: new standard module
- Sort: new standard module
- Types: numBits() and numBytes() are now param functions
- Random: fillRandom() routines now work for arrays of arbitrary rank
Compiler Flags
--------------
- improved the formatting of the --help message
- added -g flag for debugging generated code; turns on --cpp-lines by default
- added -O flag for optimizing generated code
- added -s/--set for setting config params
- added --explain-call flag that helps describe how a function call is resolved
- added --baseline flag to disable all compiler optimizations
- added --no-flow-analysis flag that disables all flow-based optimizations
- added --no-warnings flag to diable all compiler warnings
- added --no-single-loop-iterator-opt flag to disable 1-loop iterator rewrites
- added --no-expand-iterators-inline-opt flag to disable iterator inlining
- removed --unoptimized flag
- removed --cg-chpl-lineno flag; this capability is now always on
- removed --no-gc used for a stopgap reference counting scheme
Generated Code Flags
--------------------
-- added a --gdb flag to make it easier to debug generated code
Bug Fixes/New Semantic Checks (for old Semantics)
-------------------------------------------------
- test expressions in loops/conditionals restricted to bools, classes, integers
- runtime checks added to ensure that zippered iterations are of equal size
- fixed portability issues in flex lexer file, chapel.lex
- domains are now passed by reference by default
- implemented bytesPerLocale for Macintosh
- classes can now have iterator methods
- recursive iterators now work
- "true + true" now yields "2" rather than "true"
- casts from uints to complexes now supported
- casts from integral types to enumerated types now supported
- initial support for casts from strings to primitive types
- modules can now refer to param values and types from other modules correctly
- disabled parameter folding of floating point values
- parameter folding of relational operators on enum types
- parameter folding of short-circuiting &&, ||, and conditional expressions
- type aliases can now be created for array types
- fixed numerical bugs in array slicing and reindexing
- config variable initializers are no longer evaluated if set on command-line
- const values can no longer be passed to arguments with inout or out intent
- constructor keyword no longer supported -- use def <classname> instead
- fixed "bug" with log2 on integers and made it halt on zero or negatives
- improved thread safety of generated code
- made creation of too many threads result in halt() rather than lost work
- eventually we'll need to queue up tasks; this is a stopgap
- passing unions to out/inout intents now works
- better semantic checking of legal l-values
- fixed an infinite loop bug in associative domains/arrays
Error Message Improvements
--------------------------
- added message to compiler warning that "atomic" is unimplemented when used
- caused compiler to complain about non-module scope configuration variables
- unified runtime and compiler error message formats
- runtime errors identify source file/line#
- improved quality of compilerError() error message output
- cleaned up syntax error messages
- improved error message for tuples of non-param size
- improved error reporting when attempting to assign to constants
- better error checking of legal vs. illegal casts
- generally improved quality of compiler error messages
Compiler Analysis and Optimizations/Performance of Generated Code
-----------------------------------------------------------------
- removed the insertion of all large sequence/array temporaries
- extensive optimizations of iterators and loop generation
- global/local copy propagation
- dead variable elimination
- dead code elimination
- live variable analysis
- reaching definitions analysis
- def-use and use-def chains
Compiler Performance and Cleanup
--------------------------------
- improvements to function resolution, vararg function instantiation
- made compiler build with debugging off/optimizations on for non-developers
- removed unused scalar replacement code
- renamed and refactored internal modules
- removed old reference counting code
- optimized several passes to improve compile time
Generated Code
--------------
- now generating structured loops rather than gotos and labels
- large reduction in lines of generated code
e.g., ~40% reduction in lines of code for jacobi example (13275 -> 7753)
- module functions generated in order, with comments to identify source line #
- _chpl_header.h file is generated in a cleaner manner
- changed munging of variable names to improve gdb support and readability
- using pragmas, generated code has been shown to vectorize on X1/thread on MTA
- initial support for cross-compiling to the XT
Testing System
--------------
- added support for doing performance-tracking experiments
Internal
--------
- new IR traversal mechanisms
- flow analysis optimization framework
- vararg functions handled within function resolution
- parameter folding folded into function resolution
- new compiler gdb commands: lv (list view)
- domain and array wrappers now implemented as records
- improved creation of init functions
- removed ability to cast primitives to strings by casting to "%<format>"
- new mechanism for indicating that a class is promotable
- added AND_EXPAND and PRIMITIVE_TUPLE_AND_EXPAND
- added reference types
===========
version 0.4
===========
Preliminary release of Chapel Compiler, December 15, 2006
High-Level Themes
----------------
- single-locale, multiple threads
- support for base language features
- designed for correctness over performance
- target audience: HPLS language evaluation team and HPCS mission partners