TF: Clear upper bits of ConvertFloat64ToUint32 because Win64.

R=bmeurer@chromium.org
BUG=

Review URL: https://codereview.chromium.org/436623002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22765 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/compiler/x64/code-generator-x64.cc

@@ -496,6 +496,9 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
     case kSSEFloat64ToUint32: {
       // TODO(turbofan): X64 SSE cvttsd2siq should support operands.
       __ cvttsd2siq(i.OutputRegister(), i.InputDoubleRegister(0));
+      __ andl(i.OutputRegister(), i.OutputRegister());  // clear upper bits.
+      // TODO(turbofan): generated code should not look at the upper 32 bits
+      // of the result, but those bits could escape to the outside world.
       break;
     }
     case kSSEInt32ToFloat64: {

src/compiler/x64/linkage-x64.cc

@@ -14,6 +14,12 @@ namespace v8 {
 namespace internal {
 namespace compiler {
 
+#ifdef _WIN64
+const bool kWin64 = true;
+#else
+const bool kWin64 = false;
+#endif
+
 struct LinkageHelperTraits {
   static Register ReturnValueReg() { return rax; }
   static Register ReturnValue2Reg() { return rdx; }
@@ -21,26 +27,24 @@ struct LinkageHelperTraits {
   static Register ContextReg() { return rsi; }
   static Register RuntimeCallFunctionReg() { return rbx; }
   static Register RuntimeCallArgCountReg() { return rax; }
-#ifdef _WIN64
   static RegList CCalleeSaveRegisters() {
+    if (kWin64) {
       return rbx.bit() | rdi.bit() | rsi.bit() | r12.bit() | r13.bit() |
              r14.bit() | r15.bit();
+    } else {
+      return rbx.bit() | r12.bit() | r13.bit() | r14.bit() | r15.bit();
+    }
   }
   static Register CRegisterParameter(int i) {
+    if (kWin64) {
       static Register register_parameters[] = {rcx, rdx, r8, r9};
       return register_parameters[i];
-  }
-  static int CRegisterParametersLength() { return 4; }
-#else
-  static RegList CCalleeSaveRegisters() {
-    return rbx.bit() | r12.bit() | r13.bit() | r14.bit() | r15.bit();
-  }
-  static Register CRegisterParameter(int i) {
+    } else {
       static Register register_parameters[] = {rdi, rsi, rdx, rcx, r8, r9};
       return register_parameters[i];
     }
-  static int CRegisterParametersLength() { return 6; }
-#endif
+  }
+  static int CRegisterParametersLength() { return kWin64 ? 4 : 6; }
 };