SSE2 truncating double-to-i.

src/ia32/lithium-ia32.cc

Index: src/ia32/lithium-ia32.cc
diff --git a/src/ia32/lithium-ia32.cc b/src/ia32/lithium-ia32.cc
index 9999ee1eddc35585408d83d43b21e6e7ae189956..f69d054a34d629072b7f89b8e842ffe7075b95da 100644
--- a/src/ia32/lithium-ia32.cc
+++ b/src/ia32/lithium-ia32.cc
@@ -1739,8 +1739,12 @@ LInstruction* LChunkBuilder::DoChange(HChange* instr) {
       return AssignPointerMap(Define(result, result_temp));
     } else {
       ASSERT(to.IsInteger32());
-      LOperand* value = UseRegister(instr->value());
-      return AssignEnvironment(DefineAsRegister(new LDoubleToI(value)));
+      bool needs_temp = instr->CanTruncateToInt32() &&
+          !CpuFeatures::IsSupported(SSE3);
+      LOperand* value = needs_temp ?
+          UseTempRegister(instr->value()) : UseRegister(instr->value());
+      LOperand* temp = needs_temp ? TempRegister() : NULL;
+      return AssignEnvironment(DefineAsRegister(new LDoubleToI(value, temp)));
     }
   } else if (from.IsInteger32()) {
     if (to.IsTagged()) {