[hydrogen] optimize switch with string clauses

src/mips/lithium-codegen-mips.cc

Index: src/mips/lithium-codegen-mips.cc
diff --git a/src/mips/lithium-codegen-mips.cc b/src/mips/lithium-codegen-mips.cc
index ca1d2b5bb524b0e8d01fca52e55c88703578a9fb..08843b48e1aa88d1253e6294c44e5c07942319e5 100644
--- a/src/mips/lithium-codegen-mips.cc
+++ b/src/mips/lithium-codegen-mips.cc
@@ -1728,6 +1728,34 @@ void LCodeGen::DoIsObjectAndBranch(LIsObjectAndBranch* instr) {
 }
 
 
+Condition LCodeGen::EmitIsString(Register input,
+                                 Register temp1,
+                                 Label* is_not_string) {
+  __ JumpIfSmi(input, is_not_string);
+  __ GetObjectType(input, temp1, temp1);
+  __ Branch(is_not_string, ge, temp1, Operand(FIRST_NONSTRING_TYPE));
+
+  return lt;
+}
+
+
+void LCodeGen::DoIsStringAndBranch(LIsStringAndBranch* instr) {
+  Register reg = ToRegister(instr->InputAt(0));
+  Register temp1 = ToRegister(instr->TempAt(0));
+  Register temp2 = scratch0();
+
+  int true_block = chunk_->LookupDestination(instr->true_block_id());
+  int false_block = chunk_->LookupDestination(instr->false_block_id());
+  Label* false_label = chunk_->GetAssemblyLabel(false_block);
+
+  Condition true_cond =
+      EmitIsString(reg, temp1, false_label);
+
+  EmitBranch(true_block, false_block, true_cond, temp2,
+             Operand(LAST_NONCALLABLE_SPEC_OBJECT_TYPE));
+}
+
+
 void LCodeGen::DoIsSmiAndBranch(LIsSmiAndBranch* instr) {
   int true_block = chunk_->LookupDestination(instr->true_block_id());
   int false_block = chunk_->LookupDestination(instr->false_block_id());
@@ -1753,6 +1781,42 @@ void LCodeGen::DoIsUndetectableAndBranch(LIsUndetectableAndBranch* instr) {
 }
 
 
+static Condition ComputeCompareCondition(Token::Value op) {
+  switch (op) {
+    case Token::EQ_STRICT:
+    case Token::EQ:
+      return eq;
+    case Token::LT:
+      return lt;
+    case Token::GT:
+      return gt;
+    case Token::LTE:
+      return le;
+    case Token::GTE:
+      return ge;
+    default:
+      UNREACHABLE();
+      return kNoCondition;
+  }
+}
+
+
+void LCodeGen::DoStringCompareAndBranch(LStringCompareAndBranch* instr) {
+  Token::Value op = instr->op();
+  int true_block = chunk_->LookupDestination(instr->true_block_id());
+  int false_block = chunk_->LookupDestination(instr->false_block_id());
+
+  Handle<Code> ic = CompareIC::GetUninitialized(op);
+  CallCode(ic, RelocInfo::CODE_TARGET, instr);
+  // On MIPS there is no need for a "no inlined smi code" marker (nop).
+
+  Condition condition = ComputeCompareCondition(op);
+
+  EmitBranch(true_block, false_block, condition, at,
+             Operand(LAST_NONCALLABLE_SPEC_OBJECT_TYPE));
+}
+
+
 static InstanceType TestType(HHasInstanceTypeAndBranch* instr) {
   InstanceType from = instr->from();
   InstanceType to = instr->to();
@@ -2050,26 +2114,6 @@ void LCodeGen::DoDeferredLInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr,
 }
 
 
-static Condition ComputeCompareCondition(Token::Value op) {
-  switch (op) {
-    case Token::EQ_STRICT:
-    case Token::EQ:
-      return eq;
-    case Token::LT:
-      return lt;
-    case Token::GT:
-      return gt;
-    case Token::LTE:
-      return le;
-    case Token::GTE:
-      return ge;
-    default:
-      UNREACHABLE();
-      return kNoCondition;
-  }
-}
-
-
 void LCodeGen::DoCmpT(LCmpT* instr) {
   Token::Value op = instr->op();