Fix uint32-to-smi conversion in Lithium

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index e7ec59cfa89d39d11270f1664d8342511351b954..fbe8e171fa596967a65aff143823863b4570dca8 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -4650,9 +4650,7 @@ void LCodeGen::DoInteger32ToDouble(LInteger32ToDouble* instr) {
 
 void LCodeGen::DoInteger32ToSmi(LInteger32ToSmi* instr) {
   LOperand* input = instr->value();
-  ASSERT(input->IsRegister());

[Yang, 2013/10/31 09:30:57]

why do you remove these asserts?

[Jakob Kummerow, 2013/10/31 09:35:52]

Because they're useless. The subsequent ToRegister() calls contain the same
check.

   LOperand* output = instr->result();
-  ASSERT(output->IsRegister());
   __ SmiTag(ToRegister(output), ToRegister(input), SetCC);
   if (!instr->hydrogen()->value()->HasRange() ||
       !instr->hydrogen()->value()->range()->IsInSmiRange()) {
@@ -4671,6 +4669,18 @@ void LCodeGen::DoUint32ToDouble(LUint32ToDouble* instr) {
 }
 
 
+void LCodeGen::DoUint32ToSmi(LUint32ToSmi* instr) {
+  LOperand* input = instr->value();
+  LOperand* output = instr->result();
+  if (!instr->hydrogen()->value()->HasRange() ||
+      !instr->hydrogen()->value()->range()->IsInSmiRange()) {
+    __ tst(ToRegister(input), Operand(0xc0000000));
+    DeoptimizeIf(ne, instr->environment());
+  }
+  __ SmiTag(ToRegister(output), ToRegister(input));
+}
+
+
 void LCodeGen::DoNumberTagI(LNumberTagI* instr) {
   class DeferredNumberTagI V8_FINAL : public LDeferredCode {
    public: