MIPS: Landing: [hydrogen] optimize switch with string clauses.

Port r10019 (9bbb78bf)

Original commit message:
Patch by Fedor Indutny <fedor.indutny@gmail.com>.

BUG=
TEST=
Review URL: http://codereview.chromium.org/8574073

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10043 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/lithium-codegen-mips.cc

@@ -1677,6 +1677,32 @@ 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);
+
+  return lt;
+}
+
+
+void LCodeGen::DoIsStringAndBranch(LIsStringAndBranch* instr) {
+  Register reg = ToRegister(instr->InputAt(0));
+  Register temp1 = ToRegister(instr->TempAt(0));
+
+  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, temp1,
+             Operand(FIRST_NONSTRING_TYPE));
+}
+
+
 void LCodeGen::DoIsSmiAndBranch(LIsSmiAndBranch* instr) {
   int true_block = chunk_->LookupDestination(instr->true_block_id());
   int false_block = chunk_->LookupDestination(instr->false_block_id());
@@ -1702,6 +1728,40 @@ 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);
+
+  Condition condition = ComputeCompareCondition(op);
+
+  EmitBranch(true_block, false_block, condition, v0, Operand(zero_reg));
+}
+
+
 static InstanceType TestType(HHasInstanceTypeAndBranch* instr) {
   InstanceType from = instr->from();
   InstanceType to = instr->to();
@@ -2002,26 +2062,6 @@ void LCodeGen::DoDeferredInstanceOfKnownGlobal(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();
 

src/mips/lithium-codegen-mips.h

@@ -299,6 +299,13 @@ class LCodeGen BASE_EMBEDDED {
                          Label* is_not_object,
                          Label* is_object);
 
+  // Emits optimized code for %_IsString(x).  Preserves input register.
+  // Returns the condition on which a final split to
+  // true and false label should be made, to optimize fallthrough.
+  Condition EmitIsString(Register input,
+                         Register temp1,
+                         Label* is_not_string);
+
   // Emits optimized code for %_IsConstructCall().
   // Caller should branch on equal condition.
   void EmitIsConstructCall(Register temp1, Register temp2);

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 string_compare(");
+  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);
@@ -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 +1488,17 @@ LInstruction* LChunkBuilder::DoIsUndetectableAndBranch(
 }
 
 
+LInstruction* LChunkBuilder::DoStringCompareAndBranch(
+    HStringCompareAndBranch* instr) {
+  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());

src/mips/lithium-mips.h

@@ -109,8 +109,10 @@ class LCodeGen;
   V(IsConstructCallAndBranch)                   \
   V(IsNilAndBranch)                             \
   V(IsObjectAndBranch)                          \
+  V(IsStringAndBranch)                          \
   V(IsSmiAndBranch)                             \
   V(IsUndetectableAndBranch)                    \
+  V(StringCompareAndBranch)                     \
   V(JSArrayLength)                              \
   V(Label)                                      \
   V(LazyBailout)                                \
@@ -658,6 +660,20 @@ class LIsObjectAndBranch: public LControlInstruction<1, 1> {
 };
 
 
+class LIsStringAndBranch: public LControlInstruction<1, 1> {
+ public:
+  LIsStringAndBranch(LOperand* value, LOperand* temp) {
+    inputs_[0] = value;
+    temps_[0] = temp;
+  }
+
+  DECLARE_CONCRETE_INSTRUCTION(IsStringAndBranch, "is-string-and-branch")
+  DECLARE_HYDROGEN_ACCESSOR(IsStringAndBranch)
+
+  virtual void PrintDataTo(StringStream* stream);
+};
+
+
 class LIsSmiAndBranch: public LControlInstruction<1, 0> {
  public:
   explicit LIsSmiAndBranch(LOperand* value) {
@@ -686,6 +702,23 @@ class LIsUndetectableAndBranch: public LControlInstruction<1, 1> {
 };
 
 
+class LStringCompareAndBranch: public LControlInstruction<2, 0> {
+ public:
+  LStringCompareAndBranch(LOperand* left, LOperand* right) {
+    inputs_[0] = left;
+    inputs_[1] = right;
+  }
+
+  DECLARE_CONCRETE_INSTRUCTION(StringCompareAndBranch,
+                               "string-compare-and-branch")
+  DECLARE_HYDROGEN_ACCESSOR(StringCompareAndBranch)
+
+  Token::Value op() const { return hydrogen()->token(); }
+
+  virtual void PrintDataTo(StringStream* stream);
+};
+
+
 class LHasInstanceTypeAndBranch: public LControlInstruction<1, 0> {
  public:
   explicit LHasInstanceTypeAndBranch(LOperand* value) {