Bug 983709 part 1 - Don't mark shift instructions as commutative. r=h4writer

js/src/jit/MIR.cpp

@@ -1258,20 +1258,20 @@ MBinaryBitwiseInstruction::foldUnnecessaryBitop()
 void
 MBinaryBitwiseInstruction::infer(BaselineInspector *, jsbytecode *)
 {
-    if (getOperand(0)->mightBeType(MIRType_Object) || getOperand(1)->mightBeType(MIRType_Object)) {
+    if (getOperand(0)->mightBeType(MIRType_Object) || getOperand(1)->mightBeType(MIRType_Object))
         specialization_ = MIRType_None;
-    } else {
-        specialization_ = MIRType_Int32;
-        setCommutative();
-    }
+    else
+        specializeAsInt32();
 }
 
 void
-MBinaryBitwiseInstruction::specializeForAsmJS()
+MBinaryBitwiseInstruction::specializeAsInt32()
 {
     specialization_ = MIRType_Int32;
     JS_ASSERT(type() == MIRType_Int32);
-    setCommutative();
+
+    if (isBitOr() || isBitAnd() || isBitXor())
+        setCommutative();
 }
 
 void
@@ -2155,7 +2155,7 @@ MBitAnd *
 MBitAnd::NewAsmJS(TempAllocator &alloc, MDefinition *left, MDefinition *right)
 {
     MBitAnd *ins = new(alloc) MBitAnd(left, right);
-    ins->specializeForAsmJS();
+    ins->specializeAsInt32();
     return ins;
 }
 
@@ -2169,7 +2169,7 @@ MBitOr *
 MBitOr::NewAsmJS(TempAllocator &alloc, MDefinition *left, MDefinition *right)
 {
     MBitOr *ins = new(alloc) MBitOr(left, right);
-    ins->specializeForAsmJS();
+    ins->specializeAsInt32();
     return ins;
 }
 
@@ -2183,7 +2183,7 @@ MBitXor *
 MBitXor::NewAsmJS(TempAllocator &alloc, MDefinition *left, MDefinition *right)
 {
     MBitXor *ins = new(alloc) MBitXor(left, right);
-    ins->specializeForAsmJS();
+    ins->specializeAsInt32();
     return ins;
 }
 
@@ -2197,7 +2197,7 @@ MLsh *
 MLsh::NewAsmJS(TempAllocator &alloc, MDefinition *left, MDefinition *right)
 {
     MLsh *ins = new(alloc) MLsh(left, right);
-    ins->specializeForAsmJS();
+    ins->specializeAsInt32();
     return ins;
 }
 
@@ -2211,7 +2211,7 @@ MRsh *
 MRsh::NewAsmJS(TempAllocator &alloc, MDefinition *left, MDefinition *right)
 {
     MRsh *ins = new(alloc) MRsh(left, right);
-    ins->specializeForAsmJS();
+    ins->specializeAsInt32();
     return ins;
 }
 
@@ -2225,7 +2225,7 @@ MUrsh *
 MUrsh::NewAsmJS(TempAllocator &alloc, MDefinition *left, MDefinition *right)
 {
     MUrsh *ins = new(alloc) MUrsh(left, right);
-    ins->specializeForAsmJS();
+    ins->specializeAsInt32();
 
     // Since Ion has no UInt32 type, we use Int32 and we have a special
     // exception to the type rules: we can return values in

js/src/jit/MIR.h

@@ -3271,7 +3271,7 @@ class MBinaryBitwiseInstruction
         setMovable();
     }
 
-    void specializeForAsmJS();
+    void specializeAsInt32();
 
   public:
     TypePolicy *typePolicy() {