diff --git a/Makefile b/Makefile
index ed40a47e..69e1dfd5 100644
--- a/Makefile
+++ b/Makefile
@@ -469,11 +469,17 @@ else ifeq ($(platform), qnx)
 # emscripten
 else ifeq ($(platform), emscripten)
    TARGET := $(TARGET_NAME)_libretro_$(platform).bc
-   GLES := 1
-   WITH_DYNAREC :=
+   HAVE_OPENGL = 1
+   GLES = 1
 
+   HAVE_GLIDE64 = 1
+   HAVE_GLN64 = 1
+   HAVE_RICE = 0
    HAVE_PARALLEL = 0
-   CPUFLAGS += -DNOSSE -DEMSCRIPTEN -DNO_ASM -DNO_LIBCO -s USE_ZLIB=1 -s PRECISE_F32=1
+   HAVE_THR_AL = 0
+
+   CPUFLAGS += -DNOSSE -DEMSCRIPTEN -DNO_ASM -s USE_ZLIB=1
+   CPUFLAGS += -msimd128 -ftree-vectorize
 
    WITH_DYNAREC =
    CC = emcc
@@ -898,7 +904,9 @@ ifeq ($(DEBUG), 1)
       CPUOPTS += -O0 -g
    endif
 else
-ifneq (,$(findstring msvc,$(platform)))
+ifeq ($(platform), emscripten)
+   CPUOPTS += -O3
+else ifneq (,$(findstring msvc,$(platform)))
    CPUOPTS += -O2
 else
 	CPUOPTS += -Ofast
@@ -995,9 +1003,11 @@ CXXFLAGS += -DINLINE="inline"
 endif
 
 # Fix for GCC 10, make sure its added to all stages of the compiler
+ifneq ($(platform), emscripten)
 ifeq "$(shell expr `gcc -dumpversion` \>= 10)" "1"
   CPUFLAGS += -fcommon
 endif
+endif
 
 # LTO
 ifeq ($(HAVE_LTCG),1)
diff --git a/Makefile.common b/Makefile.common
index 117d232c..28fca2c9 100644
--- a/Makefile.common
+++ b/Makefile.common
@@ -24,10 +24,10 @@ ifeq ($(GLIDEN64),1)
 	HAVE_GLIDEN64 =1
 	HAVE_GLN64    =0
 else
-	HAVE_GLN64    =1
+	HAVE_GLN64    ?=1
 	HAVE_GLIDEN64 =0
 endif
-	HAVE_RICE     = 1
+	HAVE_RICE     ?= 1
 else
 	HAVE_GLIDE64 = 0
 	HAVE_GLN64    = 0
@@ -47,9 +47,7 @@ INCFLAGS += \
 	-I$(LIBRETRO_DIR)
 
 # libco
-ifneq ($(platform), emscripten)
 SOURCES_C += $(LIBRETRO_COMM_DIR)/libco/libco.c
-endif
 
 SOURCES_C += $(RSPDIR)/src/alist.c \
     $(RSPDIR)/src/alist_audio.c \
diff --git a/libretro-common/glsm/glsm.c b/libretro-common/glsm/glsm.c
index dba77f16..354fe635 100644
--- a/libretro-common/glsm/glsm.c
+++ b/libretro-common/glsm/glsm.c
@@ -638,18 +638,18 @@ void rglBlendFunc(GLenum sfactor, GLenum dfactor)
  * Core in:
  * OpenGL    : 1.4
  */
-void rglBlendFuncSeparate(GLenum sfactor, GLenum dfactor)
+void rglBlendFuncSeparate(GLenum srcRGB, GLenum dstRGB, GLenum srcAlpha, GLenum dstAlpha)
 {
 #ifdef GLSM_DEBUG
    log_cb(RETRO_LOG_INFO, "glBlendFuncSeparate.\n");
 #endif
    glsm_ctl(GLSM_CTL_IMM_VBO_DRAW, NULL);
    gl_state.blendfunc_separate.used     = true;
-   gl_state.blendfunc_separate.srcRGB   = sfactor;
-   gl_state.blendfunc_separate.dstRGB   = dfactor;
-   gl_state.blendfunc_separate.srcAlpha = sfactor;
-   gl_state.blendfunc_separate.dstAlpha = dfactor;
-   glBlendFunc(sfactor, dfactor);
+   gl_state.blendfunc_separate.srcRGB   = srcRGB;
+   gl_state.blendfunc_separate.dstRGB   = dstRGB;
+   gl_state.blendfunc_separate.srcAlpha = srcAlpha;
+   gl_state.blendfunc_separate.dstAlpha = dstAlpha;
+   glBlendFuncSeparate(srcRGB, dstRGB, srcAlpha, dstAlpha);
 }
 
 /*
diff --git a/libretro-common/libco/emscripten_fiber.c b/libretro-common/libco/emscripten_fiber.c
new file mode 100644
index 00000000..9cf98228
--- /dev/null
+++ b/libretro-common/libco/emscripten_fiber.c
@@ -0,0 +1,64 @@
+/*
+  libco.emscripten (2020-02-27)
+  authors: Toad King
+  license: public domain
+*/
+
+#define LIBCO_C
+#include <libco.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <malloc.h>
+#include <emscripten/fiber.h>
+
+#define ASYNCIFY_STACK_SIZE (131072)
+
+static thread_local emscripten_fiber_t *co_active_;
+
+static void co_thunk(void *coentry)
+{
+   ((void (*)(void))coentry)();
+}
+
+static void co_init(void)
+{
+   if (!co_active_)
+   {
+      emscripten_fiber_t *co_primary = calloc(1, sizeof(emscripten_fiber_t));
+      void *asyncify_stack = malloc(ASYNCIFY_STACK_SIZE);
+
+      emscripten_fiber_init_from_current_context(co_primary, asyncify_stack, ASYNCIFY_STACK_SIZE);
+      co_active_ = co_primary;
+   }
+}
+
+cothread_t co_active(void)
+{
+   co_init();
+   return co_active_;
+}
+
+cothread_t co_create(unsigned int stacksize, void (*coentry)(void))
+{
+   co_init();
+
+   emscripten_fiber_t *fiber = calloc(1, sizeof(emscripten_fiber_t));
+   void *asyncify_stack = malloc(ASYNCIFY_STACK_SIZE);
+   void *c_stack = memalign(16, stacksize);
+   emscripten_fiber_init(fiber, co_thunk, coentry, c_stack, stacksize, asyncify_stack, ASYNCIFY_STACK_SIZE);
+
+   return (cothread_t)fiber;
+}
+
+void co_delete(cothread_t cothread)
+{
+   free(cothread);
+}
+
+void co_switch(cothread_t cothread)
+{
+   emscripten_fiber_t *old_fiber = co_active_;
+   co_active_ = (emscripten_fiber_t *)cothread;
+
+   emscripten_fiber_swap(old_fiber, co_active_);
+}
diff --git a/libretro-common/libco/libco.c b/libretro-common/libco/libco.c
index 44a65d52..9cc996f7 100644
--- a/libretro-common/libco/libco.c
+++ b/libretro-common/libco/libco.c
@@ -9,7 +9,9 @@ void *genode_alloc_secondary_stack(unsigned long stack_size);
 void genode_free_secondary_stack(void *stack);
 #endif
 
-#if defined _MSC_VER
+#ifdef EMSCRIPTEN
+  #include "emscripten_fiber.c"
+#elif defined _MSC_VER
   #include <Windows.h>
   #if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP)
     #include "fiber.c"
diff --git a/mupen64plus-core/src/plugin/plugin.c b/mupen64plus-core/src/plugin/plugin.c
index 02d4b68d..6defa298 100644
--- a/mupen64plus-core/src/plugin/plugin.c
+++ b/mupen64plus-core/src/plugin/plugin.c
@@ -283,17 +283,23 @@ void plugin_connect_all(enum gfx_plugin_type gfx_plugin, enum rsp_plugin_type rs
          break;
       case GFX_RICE:
 #if defined(HAVE_OPENGL) || defined(HAVE_OPENGLES)
+#ifdef HAVE_RICE
          gfx = gfx_rice;
          break;
+#endif
 #endif
       case GFX_GLN64:
 #if defined(HAVE_OPENGL) || defined(HAVE_OPENGLES)
+#ifdef HAVE_GLN64
          gfx = gfx_gln64;
          break;
+#endif
 #endif
       default:
 #if defined(HAVE_OPENGL) || defined(HAVE_OPENGLES)
+#ifdef HAVE_GLIDE64
          gfx = gfx_glide64;
+#endif
 #elif defined(HAVE_THR_AL)
          gfx = gfx_angrylion;
 #endif