[hydrogen] optimize switch with string clauses

src/mips/lithium-mips.cc

Index: src/mips/lithium-mips.cc
diff --git a/src/mips/lithium-mips.cc b/src/mips/lithium-mips.cc
index 96f06b92f6c99a2e25b3ec8ba5b09133e5f4156a..f4a44342cfad43189fcd6c96c5e4c9f186dc8339 100644
--- a/src/mips/lithium-mips.cc
+++ b/src/mips/lithium-mips.cc
@@ -228,6 +228,13 @@ 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);
@@ -242,6 +249,14 @@ void LIsUndetectableAndBranch::PrintDataTo(StringStream* stream) {
 }
 
 
+void LStringCompareAndBranch::PrintDataTo(StringStream* stream) {
+  stream->Add("if compare_generic(");
+  InputAt(0)->PrintTo(stream);
+  InputAt(1)->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);
@@ -1401,7 +1416,7 @@ LInstruction* LChunkBuilder::DoCompareGeneric(HCompareGeneric* instr) {
   LOperand* left = UseFixed(instr->left(), a1);
   LOperand* right = UseFixed(instr->right(), a0);
   LCmpT* result = new LCmpT(left, right);
-  return MarkAsCall(DefineFixed(result, v0), instr);
+  return AssignEnvironment(MarkAsCall(DefineFixed(result, v0), instr));
 }
 
 
@@ -1452,6 +1467,13 @@ LInstruction* LChunkBuilder::DoIsObjectAndBranch(HIsObjectAndBranch* instr) {
 }
 
 
+LInstruction* LChunkBuilder::DoIsStringAndBranch(HIsStringAndBranch* instr) {
+  ASSERT(instr->value()->representation().IsTagged());
+  LOperand* temp = TempRegister();
+  return new LIsStringAndBranch(UseRegisterAtStart(instr->value()), temp);
+}
+
+
 LInstruction* LChunkBuilder::DoIsSmiAndBranch(HIsSmiAndBranch* instr) {
   ASSERT(instr->value()->representation().IsTagged());
   return new LIsSmiAndBranch(Use(instr->value()));
@@ -1466,6 +1488,18 @@ LInstruction* LChunkBuilder::DoIsUndetectableAndBranch(
 }
 
 
+LInstruction* LChunkBuilder::DoStringCompareAndBranch(
+    HStringCompareAndBranch* instr) {
+  Representation r = instr->GetInputRepresentation();
+  ASSERT(instr->left()->representation().IsTagged());
+  ASSERT(instr->right()->representation().IsTagged());
+  LOperand* left = UseFixed(instr->left(), a1);
+  LOperand* right = UseFixed(instr->right(), a0);
+  LStringCompareAndBranch* result = new LStringCompareAndBranch(left, right);
+  return MarkAsCall(result, instr);
+}
+
+
 LInstruction* LChunkBuilder::DoHasInstanceTypeAndBranch(
     HHasInstanceTypeAndBranch* instr) {
   ASSERT(instr->value()->representation().IsTagged());