run multiple js optimizer passes in batches

1 files changed, 32 insertions, 19 deletions

diff --git a/emcc b/emcc
index 090288b5..2a575559 100755
--- a/emcc
+++ b/emcc
@@ -524,34 +524,47 @@ try:
     Popen(js_transform.split(' ') + [os.path.abspath(final)]).communicate()
     if DEBUG: save_intermediate('transformed')
 
+  # It is useful to run several js optimizer passes together, to save on unneeded unparsing/reparsing
+  js_optimizer_queue = []
+  def flush_js_optimizer_queue():
+    global final, js_optimizer_queue
+    if len(js_optimizer_queue) > 0:
+      if not DEBUG:
+        final = shared.Building.js_optimizer(final, js_optimizer_queue)
+      else:
+        for name in js_optimizer_queue:
+          print >> sys.stderr, 'emcc: applying js optimization pass:', name
+          final = shared.Building.js_optimizer(final, [name])
+          save_intermediate(name)
+      js_optimizer_queue = []
+
   if opt_level >= 1:
     if DEBUG: print >> sys.stderr, 'emcc: running pre-closure post-opts'
 
-    final = shared.Building.js_optimizer(final, []) # Clean up the syntax a bit
-    if DEBUG: save_intermediate('pretty')
+    if DEBUG:
+      # Clean up the syntax a bit
+      final = shared.Building.js_optimizer(final, [])
+      if DEBUG: save_intermediate('pretty')
 
     if shared.Settings.RELOOP:
-      # js optimizer
-      final = shared.Building.js_optimizer(final, ['hoistMultiples'])
-      if DEBUG: save_intermediate('hoistMultiples')
-      final = shared.Building.js_optimizer(final, ['loopOptimizer'])
-      if DEBUG: save_intermediate('loopOptimizer')
+      js_optimizer_queue += ['hoistMultiples', 'loopOptimizer']
+
+    flush_js_optimizer_queue()
 
     # eliminator
+    if DEBUG: print >> sys.stderr, 'emcc: running variable eliminator'
     final = shared.Building.eliminator(final)
     if DEBUG: save_intermediate('eliminator')
 
     # js optimizer pre-pass
-    final = shared.Building.js_optimizer(final, 'simplifyExpressionsPre')
-    if DEBUG: save_intermediate('simplifyExpressionsPre')
-    final = shared.Building.js_optimizer(final, 'optimizeShiftsConservative')
-    if DEBUG: save_intermediate('optimizeShiftsConservative')
-    #final = shared.Building.js_optimizer(final, 'optimizeShiftsAggressive')
-    #if DEBUG: save_intermediate('optimizeShiftsAggressive')
-    #final = shared.Building.eliminator(final) # aggressive shifts optimization introduces some new variables, remove ones that we can
-    #if DEBUG: save_intermediate('eliminator')
+    js_optimizer_queue += ['simplifyExpressionsPre', 'optimizeShiftsConservative']
+    ###js_optimizer_queue += ['optimizeShiftsAggressive']
+    ###final = shared.Building.eliminator(final) # aggressive shifts optimization introduces some new variables, remove ones that we can
+    ###if DEBUG: save_intermediate('eliminator')
 
   if closure:
+    flush_js_optimizer_queue()
+
     if DEBUG: print >> sys.stderr, 'emcc: running closure'
     final = shared.Building.closure_compiler(final)
     if DEBUG: save_intermediate('closure')
@@ -559,12 +572,12 @@ try:
   if opt_level >= 1:
     # js optimizer post-pass
     if DEBUG: print >> sys.stderr, 'emcc: running post-closure post-opts'
-    final = shared.Building.js_optimizer(final, 'simplifyExpressionsPost')
-    if DEBUG: save_intermediate('simplifyExpressionsPost')
+    js_optimizer_queue += ['simplifyExpressionsPost']
 
   if compress_whitespace:
-    final = shared.Building.js_optimizer(final, 'compress')
-    if DEBUG: save_intermediate('compress')
+    js_optimizer_queue += ['compress']
+
+  flush_js_optimizer_queue()
 
   # If we were asked to also generate HTML, do that
   if final_suffix == 'html':