MIPS: Avoid Unnecessary Smi Checks.

Port r15344 (9fd1942)

BUG=

Review URL: https://codereview.chromium.org/17887007
Patch from Balazs Kilvady <kilvadyb@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15345 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/lithium-codegen-mips.cc

@@ -1709,9 +1709,11 @@ void LCodeGen::DoValueOf(LValueOf* instr) {
   Register map = ToRegister(instr->temp());
   Label done;
 
-  // If the object is a smi return the object.
-  __ Move(result, input);
-  __ JumpIfSmi(input, &done);
+  if (!instr->hydrogen()->value()->IsHeapObject()) {
+    // If the object is a smi return the object.
+    __ Move(result, input);
+    __ JumpIfSmi(input, &done);
+  }
 
   // If the object is not a value type, return the object.
   __ GetObjectType(input, map, map);
@@ -2305,8 +2307,11 @@ void LCodeGen::DoIsObjectAndBranch(LIsObjectAndBranch* instr) {
 
 Condition LCodeGen::EmitIsString(Register input,
                                  Register temp1,
-                                 Label* is_not_string) {
-  __ JumpIfSmi(input, is_not_string);
+                                 Label* is_not_string,
+                                 SmiCheck check_needed = INLINE_SMI_CHECK) {
+  if (check_needed == INLINE_SMI_CHECK) {
+    __ JumpIfSmi(input, is_not_string);
+  }
   __ GetObjectType(input, temp1, temp1);
 
   return lt;
@@ -2317,8 +2322,11 @@ void LCodeGen::DoIsStringAndBranch(LIsStringAndBranch* instr) {
   Register reg = ToRegister(instr->value());
   Register temp1 = ToRegister(instr->temp());
 
+  SmiCheck check_needed =
+      instr->hydrogen()->value()->IsHeapObject()
+          ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
   Condition true_cond =
-      EmitIsString(reg, temp1, instr->FalseLabel(chunk_));
+      EmitIsString(reg, temp1, instr->FalseLabel(chunk_), check_needed);
 
   EmitBranch(instr, true_cond, temp1,
              Operand(FIRST_NONSTRING_TYPE));
@@ -2336,7 +2344,9 @@ void LCodeGen::DoIsUndetectableAndBranch(LIsUndetectableAndBranch* instr) {
   Register input = ToRegister(instr->value());
   Register temp = ToRegister(instr->temp());
 
-  __ JumpIfSmi(input, instr->FalseLabel(chunk_));
+  if (!instr->hydrogen()->value()->IsHeapObject()) {
+    __ JumpIfSmi(input, instr->FalseLabel(chunk_));
+  }
   __ lw(temp, FieldMemOperand(input, HeapObject::kMapOffset));
   __ lbu(temp, FieldMemOperand(temp, Map::kBitFieldOffset));
   __ And(at, temp, Operand(1 << Map::kIsUndetectable));
@@ -2400,7 +2410,9 @@ void LCodeGen::DoHasInstanceTypeAndBranch(LHasInstanceTypeAndBranch* instr) {
   Register scratch = scratch0();
   Register input = ToRegister(instr->value());
 
-  __ JumpIfSmi(input, instr->FalseLabel(chunk_));
+  if (!instr->hydrogen()->value()->IsHeapObject()) {
+    __ JumpIfSmi(input, instr->FalseLabel(chunk_));
+  }
 
   __ GetObjectType(input, scratch, scratch);
   EmitBranch(instr,
@@ -2837,9 +2849,9 @@ void LCodeGen::DoStoreContextSlot(LStoreContextSlot* instr) {
 
   __ sw(value, target);
   if (instr->hydrogen()->NeedsWriteBarrier()) {
-    HType type = instr->hydrogen()->value()->type();
     SmiCheck check_needed =
-        type.IsHeapObject() ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
+        instr->hydrogen()->value()->IsHeapObject()
+            ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
     __ RecordWriteContextSlot(context,
                               target.offset(),
                               value,
@@ -4127,9 +4139,9 @@ void LCodeGen::DoStoreNamedField(LStoreNamedField* instr) {
   // Do the store.
   Register value = ToRegister(instr->value());
   ASSERT(!object.is(value));
-  HType type = instr->hydrogen()->value()->type();
   SmiCheck check_needed =
-      type.IsHeapObject() ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
+      instr->hydrogen()->value()->IsHeapObject()
+          ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
   if (access.IsInobject()) {
     __ sw(value, FieldMemOperand(object, offset));
     if (instr->hydrogen()->NeedsWriteBarrier()) {
@@ -4354,9 +4366,9 @@ void LCodeGen::DoStoreKeyedFixedArray(LStoreKeyed* instr) {
   __ sw(value, FieldMemOperand(store_base, offset));
 
   if (instr->hydrogen()->NeedsWriteBarrier()) {
-    HType type = instr->hydrogen()->value()->type();
     SmiCheck check_needed =
-       type.IsHeapObject() ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
+        instr->hydrogen()->value()->IsHeapObject()
+            ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
     // Compute address of modified element and store it into key register.
     __ Addu(key, store_base, Operand(offset - kHeapObjectTag));
     __ RecordWrite(elements,
@@ -5107,9 +5119,11 @@ void LCodeGen::DoCheckSmi(LCheckSmi* instr) {
 
 
 void LCodeGen::DoCheckNonSmi(LCheckNonSmi* instr) {
-  LOperand* input = instr->value();
-  __ And(at, ToRegister(input), Operand(kSmiTagMask));
-  DeoptimizeIf(eq, instr->environment(), at, Operand(zero_reg));
+  if (!instr->hydrogen()->value()->IsHeapObject()) {
+    LOperand* input = instr->value();
+    __ And(at, ToRegister(input), Operand(kSmiTagMask));
+    DeoptimizeIf(eq, instr->environment(), at, Operand(zero_reg));
+  }
 }
 
 

src/mips/lithium-codegen-mips.h

@@ -365,7 +365,8 @@ class LCodeGen BASE_EMBEDDED {
   // true and false label should be made, to optimize fallthrough.
   Condition EmitIsString(Register input,
                          Register temp1,
-                         Label* is_not_string);
+                         Label* is_not_string,
+                         SmiCheck check_needed);
 
   // Emits optimized code for %_IsConstructCall().
   // Caller should branch on equal condition.

src/mips/lithium-mips.cc

@@ -1920,7 +1920,7 @@ LInstruction* LChunkBuilder::DoChange(HChange* instr) {
 }
 
 
-LInstruction* LChunkBuilder::DoCheckNonSmi(HCheckNonSmi* instr) {
+LInstruction* LChunkBuilder::DoCheckHeapObject(HCheckHeapObject* instr) {
   LOperand* value = UseRegisterAtStart(instr->value());
   return AssignEnvironment(new(zone()) LCheckNonSmi(value));
 }

src/mips/lithium-mips.h

@@ -2394,6 +2394,7 @@ class LCheckNonSmi: public LTemplateInstruction<0, 1, 0> {
   LOperand* value() { return inputs_[0]; }
 
   DECLARE_CONCRETE_INSTRUCTION(CheckNonSmi, "check-non-smi")
+  DECLARE_HYDROGEN_ACCESSOR(CheckHeapObject)
 };