Collect type feedback on result of Math.[round|ceil|floor]

src/hydrogen.cc

Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index 937f5b086b41029a1e4c70130ae3953cca3d1fe8..5f6e86bb28c0933b618153a726b70562ff0daf2c 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -8330,8 +8330,13 @@ bool HOptimizedGraphBuilder::TryInlineBuiltinFunctionCall(Call* expr) {
       if (!FLAG_fast_math) break;
       // Fall through if FLAG_fast_math.
     case kMathRound:
-    case kMathFround:
     case kMathFloor:
+      // If round has seen minus zero, don't inline, since that assumes
+      // returned value is an integer, which -0 definitely is not.
+      if (expr->ShouldHandleMinusZeroResult()) {
+        break;
+      }
+    case kMathFround:
     case kMathAbs:
     case kMathSqrt:
     case kMathLog:
@@ -8344,6 +8349,28 @@ bool HOptimizedGraphBuilder::TryInlineBuiltinFunctionCall(Call* expr) {
         return true;
       }
       break;
+    case kMathCeil:
+      // If round/floor has seen minus zero, don't inline, since that assumes
+      // returned value is an integer, which -0 definitely is not.
+      if (expr->ShouldHandleMinusZeroResult()) {
+        break;
+      }
+      if (expr->arguments()->length() == 1) {
+        HValue* argument = Pop();
+        Drop(2);  // Receiver and function.
+        HValue* op = NULL;
+        {
+          NoObservableSideEffectsScope s(this);
+          HValue* neg_arg =
+              AddUncasted<HMul>(graph()->GetConstantMinus1(), argument);
+          op = AddUncasted<HUnaryMathOperation>(neg_arg, kMathFloor);
+        }
+        HInstruction* neg_op =
+            NewUncasted<HMul>(graph()->GetConstantMinus1(), op);
+        ast_context()->ReturnInstruction(neg_op, expr->id());
+        return true;
+      }
+      break;
     case kMathImul:
       if (expr->arguments()->length() == 2) {
         HValue* right = Pop();
@@ -8437,8 +8464,13 @@ bool HOptimizedGraphBuilder::TryInlineBuiltinMethodCall(
       if (!FLAG_fast_math) break;
       // Fall through if FLAG_fast_math.
     case kMathRound:
-    case kMathFround:
     case kMathFloor:
+      // If round/floor has seen minus zero, don't inline, since that assumes
+      // returned value is an integer, which -0 definitely is not.
+      if (expr->ShouldHandleMinusZeroResult()) {
+        break;
+      }
+    case kMathFround:
     case kMathAbs:
     case kMathSqrt:
     case kMathLog:
@@ -8451,6 +8483,28 @@ bool HOptimizedGraphBuilder::TryInlineBuiltinMethodCall(
         return true;
       }
       break;
+    case kMathCeil:
+      // If round/floor has seen minus zero, don't inline, since that assumes
+      // returned value is an integer, which -0 definitely is not.
+      if (expr->ShouldHandleMinusZeroResult()) {
+        break;
+      }
+      if (argument_count == 2) {
+        HValue* argument = Pop();
+        Drop(2);  // Receiver and function.
+        HValue* op = NULL;
+        {
+          NoObservableSideEffectsScope s(this);

[mvstanton, 2015/05/04 09:41:22]

Why does this have to be in a NoObservableSideEffectsScope?

[danno, 2015/05/04 14:31:56]

Otherwise there are missing simulates after the following instructions. The
simulate only needs to happen after the final HMul.

+          HValue* neg_arg =
+              AddUncasted<HMul>(graph()->GetConstantMinus1(), argument);
+          op = AddUncasted<HUnaryMathOperation>(neg_arg, kMathFloor);
+        }
+        HInstruction* neg_op =
+            NewUncasted<HMul>(graph()->GetConstantMinus1(), op);
+        ast_context()->ReturnInstruction(neg_op, expr->id());
+        return true;
+      }
+      break;
     case kMathPow:
       if (argument_count == 3) {
         HValue* right = Pop();
@@ -12186,15 +12240,6 @@ void HOptimizedGraphBuilder::GenerateMathClz32(CallRuntime* call) {
 }
 
 
-void HOptimizedGraphBuilder::GenerateMathFloor(CallRuntime* call) {
-  DCHECK(call->arguments()->length() == 1);
-  CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));
-  HValue* value = Pop();
-  HInstruction* result = NewUncasted<HUnaryMathOperation>(value, kMathFloor);
-  return ast_context()->ReturnInstruction(result, call->id());
-}
-
-
 void HOptimizedGraphBuilder::GenerateMathLogRT(CallRuntime* call) {
   DCHECK(call->arguments()->length() == 1);
   CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));