Eliminator: prevent inlining into loops & fix for circular dependencies.

3 files changed, 50 insertions, 15 deletions

diff --git a/tools/eliminator/eliminator-test-output.js b/tools/eliminator/eliminator-test-output.js
index 1480f5e5..19faa80d 100644
--- a/tools/eliminator/eliminator-test-output.js
+++ b/tools/eliminator/eliminator-test-output.js
@@ -10,7 +10,7 @@ var g = function(a1, a2) {
   
   var c = a * 2 - 1;
   
-  a++;
+  a = c;
   foo(c);
   
   foo(2);
@@ -62,6 +62,16 @@ function h() {
     x = y ? x + 1 : 7;
     var x = -5;
   }
+  
+  if (1) {
+    otherGlob = glob;
+    breakMe();
+  }
+  var oneUse2 = glob2;
+  while (1) {
+    otherGlob2 = oneUse2;
+    breakMe();
+  }
   return out;
 }
 function strtok_part(b, j, f) {
@@ -77,7 +87,7 @@ function strtok_part(b, j, f) {
 function py() {
   
   
-  
-  
-  HEAP[HEAP[__PyThreadState_Current] + 12] = HEAP[HEAP[__PyThreadState_Current] + 12] + 1;
+  var $7 = HEAP[HEAP[__PyThreadState_Current] + 12] + 1;
+  var $8 = HEAP[__PyThreadState_Current] + 12;
+  HEAP[$8] = $7;
 }
diff --git a/tools/eliminator/eliminator-test.js b/tools/eliminator/eliminator-test.js
index 88ea409c..8a364c0a 100644
--- a/tools/eliminator/eliminator-test.js
+++ b/tools/eliminator/eliminator-test.js
@@ -10,7 +10,7 @@ var g = function (a1, a2) {
   var b = a * 2;
   var c = b - 1;
   var qqq = "qwe";
-  a++;
+  a = c;
   foo(c);
   var ww = 1, www, zzz = 2;
   foo(zzz);
@@ -62,6 +62,16 @@ function h() {
     x = y ? x + 1 : 7;
     var x = -5;
   }
+  var oneUse = glob;
+  if (1) {
+    otherGlob = oneUse;
+    breakMe();
+  }
+  var oneUse2 = glob2;
+  while (1) {
+    otherGlob2 = oneUse2;
+    breakMe();
+  }
   return out;
 }
 function strtok_part(b, j, f) {
diff --git a/tools/eliminator/eliminator.coffee b/tools/eliminator/eliminator.coffee
index 08670096..c07e5974 100644
--- a/tools/eliminator/eliminator.coffee
+++ b/tools/eliminator/eliminator.coffee
@@ -204,10 +204,8 @@ class Eliminator
   #   depsMutatedInLiveRange
   analyzeLiveRanges: ->
     isLive = {}
-    isDead = {}
 
-    # Checks if a given note may mutate any of the currently live variables, and
-    # if so, adds them to isDead.
+    # Checks if a given node may mutate any of the currently live variables.
     checkForMutations = (node, type) =>
       usedInThisStatement = {}
       if type in ['assign', 'call']
@@ -223,34 +221,51 @@ class Eliminator
           reference = reference[1]
           if @dependsOn[reference]?
             for varName of @dependsOn[reference]
-              if isLive[varName] and not usedInThisStatement[varName]
-                isDead[varName] = true
+              if isLive[varName]
+                isLive[varName] = false
 
       if type of CONTROL_FLOW_NODES
         for varName of isLive
           if @dependsOnAGlobal[varName] or not usedInThisStatement[varName]
-            isDead[varName] = true
+            isLive[varName] = false
       else if type is 'assign'
         for varName of isLive
           if @dependsOnAGlobal[varName] and not usedInThisStatement[varName]
-            isDead[varName] = true
+            isLive[varName] = false
       else if type is 'name'
         reference = node[1]
         if @isSingleDef[reference]
-          if isDead[reference] or not isLive[reference]
+          if not isLive[reference]
             @depsMutatedInLiveRange[reference] = true
       return undefined
 
     # Analyzes a block and all its children for variable ranges. Makes sure to
     # account for the worst case of possible mutations.
     analyzeBlock = (node, type) =>
-      if type in ['if', 'do', 'while', 'for', 'for-in', 'try']
-        for child in node
+      if type in ['switch', 'if', 'try', 'do', 'while', 'for', 'for-in']
+        traverseChild = (child) ->
           if typeof child == 'object' and child?.length
             savedLive = {}
             for name of isLive then savedLive[name] = true
             traverse child, analyzeBlock
+            for name of isLive
+              if not isLive[name] then savedLive[name] = false
             isLive = savedLive
+        if type is 'switch'
+          traverseChild node[1]
+          for child in node[2]
+            traverseChild child
+        else if type in ['if', 'try']
+          for child in node
+            traverseChild child
+        else
+          # Don't put anything from outside into the body of a loop.
+          savedLive = isLive
+          isLive = {}
+          for child in node then traverseChild child
+          for name of isLive
+            if not isLive[name] then savedLive[name] = false
+          isLive = savedLive
         return node
       else if type is 'var'
         for [varName, varValue] in node[1]