Hydrogen binop improvements

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index 7d3b879fb90bf79d46f47d07ca3b543aff71fc13..ca1e21e0cf3a2a7c210f40cb4e4d2b4ad2ec3f14 100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -3881,16 +3881,21 @@ class HBitwiseBinaryOperation : public HBinaryOperation {
     SetFlag(kTruncatingToInt32);
     SetFlag(kAllowUndefinedAsNaN);
     SetAllSideEffects();
+    if (left->IsForceRepresentation()) {

[Sven Panne, 2013/09/16 13:38:09]

Why do we propagate back only to HForceRepresentation? This looks weird...

[oliv, 2013/09/16 15:44:43]

It is actually even wrong in the general case, sorry

+      left->SetFlag(kTruncatingToInt32);
+    }
+    if (right->IsForceRepresentation()) {
+      right->SetFlag(kTruncatingToInt32);
+    }
   }
 
   virtual void RepresentationChanged(Representation to) V8_OVERRIDE {
-    if (!to.IsTagged()) {
-      ASSERT(to.IsSmiOrInteger32());
-      ClearAllSideEffects();
-      SetFlag(kUseGVN);
-    } else {
+    if (to.IsTagged()) {
       SetAllSideEffects();
       ClearFlag(kUseGVN);
+    } else {
+      ClearAllSideEffects();
+      SetFlag(kUseGVN);
     }
   }
 
@@ -4524,10 +4529,12 @@ class HMul V8_FINAL : public HArithmeticBinaryOperation {
                            HValue* right);
 
   static HInstruction* NewImul(Zone* zone,
-                               HValue* context,
-                               HValue* left,
-                               HValue* right) {
-    HMul* mul = new(zone) HMul(context, left, right);
+                         HValue* context,
+                         HValue* left,
+                         HValue* right) {
+    HInstruction* instr = HMul::New(zone, context, left, right);
+    if (!instr->IsMul()) return instr;
+    HMul* mul = HMul::cast(instr);
     // TODO(mstarzinger): Prevent bailout on minus zero for imul.
     mul->AssumeRepresentation(Representation::Integer32());
     mul->ClearFlag(HValue::kCanOverflow);
@@ -6494,14 +6501,20 @@ class HStringAdd V8_FINAL : public HBinaryOperation {
   HStringAdd(HValue* context, HValue* left, HValue* right, StringAddFlags flags)
       : HBinaryOperation(context, left, right, HType::String()), flags_(flags) {
     set_representation(Representation::Tagged());
-    SetFlag(kUseGVN);
-    SetGVNFlag(kDependsOnMaps);
-    SetGVNFlag(kChangesNewSpacePromotion);
+    if (flags_ == STRING_ADD_CHECK_NONE) {
+      SetFlag(kUseGVN);
+      SetGVNFlag(kDependsOnMaps);
+      SetGVNFlag(kChangesNewSpacePromotion);
+    } else {
+      SetAllSideEffects();
+    }
   }
 
   // No side-effects except possible allocation.
   // NOTE: this instruction _does not_ call ToString() on its inputs.
-  virtual bool IsDeletable() const V8_OVERRIDE { return true; }
+  virtual bool IsDeletable() const V8_OVERRIDE {
+    return flags_ == STRING_ADD_CHECK_NONE;
+  }
 
   const StringAddFlags flags_;
 };