--- spack-src/configure.org	2021-01-18 10:12:04.000000000 +0900
+++ spack-src/configure	2021-01-20 20:26:16.000000000 +0900
@@ -17412,7 +17412,7 @@
       case "${enable_optim}" in
         aggressive)
           enable_optim_opt="aggressive"
-          CFLAGS_OPTIM="-O3 -mtune=native -march=native"
+          CFLAGS_OPTIM="-O3 -mtune=native "
           ;;
         safe)
           enable_optim_opt="safe"
@@ -17420,7 +17420,7 @@
           ;;
         standard)
           enable_optim_opt="standard"
-          CFLAGS_OPTIM="-O2 -mtune=native -march=native"
+          CFLAGS_OPTIM="-O2 -mtune=native "
           ;;
       esac   # [case: enable_optim, indent: 2, item: True]
       ;;
@@ -17641,7 +17641,7 @@
       case "${enable_optim}" in
         aggressive)
           enable_optim_opt="aggressive"
-          CXXFLAGS_OPTIM="-O3 -mtune=native -march=native"
+          CXXFLAGS_OPTIM="-O3 -mtune=native "
           ;;
         safe)
           enable_optim_opt="safe"
@@ -17649,7 +17649,7 @@
           ;;
         standard)
           enable_optim_opt="standard"
-          CXXFLAGS_OPTIM="-O2 -mtune=native -march=native"
+          CXXFLAGS_OPTIM="-O2 -mtune=native "
           ;;
       esac   # [case: enable_optim, indent: 2, item: True]
       ;;
@@ -17815,7 +17815,7 @@
           case "${enable_optim}" in
             aggressive)
               enable_optim_opt="aggressive"
-              FCFLAGS_OPTIM="-O3 -mtune=native -march=native -faggressive-function-elimination -fstack-arrays"
+              FCFLAGS_OPTIM="-O3 -mtune=native  -faggressive-function-elimination -fstack-arrays"
               ;;
             safe)
               enable_optim_opt="safe"
@@ -17823,7 +17823,7 @@
               ;;
             standard)
               enable_optim_opt="standard"
-              FCFLAGS_OPTIM="-O2 -mtune=native -march=native"
+              FCFLAGS_OPTIM="-O2 -mtune=native "
               ;;
           esac   # [case: enable_optim, indent: 4, item: True]
           ;;
@@ -17833,7 +17833,7 @@
           case "${enable_optim}" in
             aggressive)
               enable_optim_opt="aggressive"
-              FCFLAGS_OPTIM="-O3 -mtune=native -march=native -funroll-loops -faggressive-function-elimination"
+              FCFLAGS_OPTIM="-O3 -mtune=native  -funroll-loops -faggressive-function-elimination"
               ;;
             safe)
               enable_optim_opt="safe"
@@ -17841,7 +17841,7 @@
               ;;
             standard)
               enable_optim_opt="standard"
-              FCFLAGS_OPTIM="-O2 -mtune=native -march=native"
+              FCFLAGS_OPTIM="-O2 -mtune=native "
               ;;
           esac   # [case: enable_optim, indent: 4, item: True]
           ;;