[hydrogen] optimize switch with string clauses

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 1f01df62f7c6fe4b3335e72ea40d8b5dd5bd32a6..b618c3798e775a878f21980bd36e152415251c39 100644
--- a/src/ia32/lithium-ia32.cc
+++ b/src/ia32/lithium-ia32.cc
@@ -225,6 +225,13 @@ void LIsObjectAndBranch::PrintDataTo(StringStream* stream) {
 }
 
 
+void LIsStringAndBranch::PrintDataTo(StringStream* stream) {
+  stream->Add("if is_string(");
+  InputAt(0)->PrintTo(stream);
+  stream->Add(") then B%d else B%d", true_block_id(), false_block_id());
+}
+
+
 void LIsSmiAndBranch::PrintDataTo(StringStream* stream) {
   stream->Add("if is_smi(");
   InputAt(0)->PrintTo(stream);
@@ -239,6 +246,14 @@ void LIsUndetectableAndBranch::PrintDataTo(StringStream* stream) {
 }
 
 
+void LStringCompareAndBranch::PrintDataTo(StringStream* stream) {
+  stream->Add("if compare_generic(");
+  InputAt(1)->PrintTo(stream);
+  InputAt(2)->PrintTo(stream);
+  stream->Add(") then B%d else B%d", true_block_id(), false_block_id());
+}
+
+
 void LHasInstanceTypeAndBranch::PrintDataTo(StringStream* stream) {
   stream->Add("if has_instance_type(");
   InputAt(0)->PrintTo(stream);
@@ -1499,6 +1514,13 @@ LInstruction* LChunkBuilder::DoIsObjectAndBranch(HIsObjectAndBranch* instr) {
 }
 
 
+LInstruction* LChunkBuilder::DoIsStringAndBranch(HIsStringAndBranch* instr) {
+  ASSERT(instr->value()->representation().IsTagged());
+  LOperand* temp = TempRegister();
+  return new LIsStringAndBranch(UseRegister(instr->value()), temp);
+}
+
+
 LInstruction* LChunkBuilder::DoIsSmiAndBranch(HIsSmiAndBranch* instr) {
   ASSERT(instr->value()->representation().IsTagged());
   return new(zone()) LIsSmiAndBranch(Use(instr->value()));
@@ -1513,6 +1535,21 @@ LInstruction* LChunkBuilder::DoIsUndetectableAndBranch(
 }
 
 
+LInstruction* LChunkBuilder::DoStringCompareAndBranch(
+    HStringCompareAndBranch* instr) {
+  ASSERT(instr->left()->representation().IsTagged());
+  ASSERT(instr->right()->representation().IsTagged());
+  LOperand* context = UseFixed(instr->context(), esi);
+  LOperand* left = UseFixed(instr->left(), edx);
+  LOperand* right = UseFixed(instr->right(), eax);
+
+  LStringCompareAndBranch* result = new
+      LStringCompareAndBranch(context, left, right);
+
+  return MarkAsCall(result, instr);
+}
+
+
 LInstruction* LChunkBuilder::DoHasInstanceTypeAndBranch(
     HHasInstanceTypeAndBranch* instr) {
   ASSERT(instr->value()->representation().IsTagged());