use llvm internalive and globaldce to remove unneeded code before compiling to js

1 files changed, 6 insertions, 0 deletions

diff --git a/emcc b/emcc
index d2b5004c..6461dbb7 100755
--- a/emcc
+++ b/emcc
@@ -512,6 +512,11 @@ try:
   if llvm_opt_level > 0 and not LEAVE_INPUTS_RAW:
     if DEBUG: print >> sys.stderr, 'emcc: LLVM opts'
     shared.Building.llvm_opt(in_temp(target_basename + '.bc'), LLVM_INTERNAL_OPT_LEVEL, safe=llvm_opt_level < 2)
+  else:
+    # If possible, remove dead functions etc., this potentially saves a lot in the size of the generated code (and the time to compile it)
+    if not shared.Settings.BUILD_AS_SHARED_LIB:
+      if DEBUG: print >> sys.stderr, 'emcc: LLVM dead globals elimination'
+      shared.Building.llvm_opt(in_temp(target_basename + '.bc'), ['-internalize', '-globaldce'])
 
   # Emscripten
   try:
@@ -531,6 +536,7 @@ try:
 
   if not LEAVE_INPUTS_RAW:
     final = in_temp(target_basename + '.bc')
+    if DEBUG: save_intermediate('bc', 'bc')
     final = shared.Building.llvm_dis(final, final + '.ll')
     if DEBUG: save_intermediate('ll', 'll')
   else: