Crankshaft support for polymorphic array handling

src/ia32/lithium-codegen-ia32.cc

Index: src/ia32/lithium-codegen-ia32.cc
diff --git a/src/ia32/lithium-codegen-ia32.cc b/src/ia32/lithium-codegen-ia32.cc
index 984d4eb0a8f007041417c31004b15af4565afd5a..229f56a37263e10edcd0f4db9a67194d70729a81 100644
--- a/src/ia32/lithium-codegen-ia32.cc
+++ b/src/ia32/lithium-codegen-ia32.cc
@@ -1213,6 +1213,21 @@ void LCodeGen::DoExternalArrayLength(LExternalArrayLength* instr) {
 }
 
 
+void LCodeGen::DoElementsKind(LElementsKind* instr) {
+  Register result = ToRegister(instr->result());
+  Register input = ToRegister(instr->InputAt(0));
+
+  // Load map into |result|.
+  __ mov(result, FieldOperand(input, HeapObject::kMapOffset));
+  // Load map's "bit field 2" into |result|. We only need the first byte,
+  // but the following masking takes care of that anyway.
+  __ mov(result, FieldOperand(result, Map::kBitField2Offset));
+  // Retrieve elements_kind from bit field 2.
+  __ and_(result, Map::kElementsKindMask);
+  __ shr(result, Map::kElementsKindShift);
+}
+
+
 void LCodeGen::DoValueOf(LValueOf* instr) {
   Register input = ToRegister(instr->InputAt(0));
   Register result = ToRegister(instr->result());
@@ -1583,6 +1598,29 @@ void LCodeGen::DoCmpSymbolEqAndBranch(LCmpSymbolEqAndBranch* instr) {
 }
 
 
+void LCodeGen::DoCmpWithConstant(LCmpWithConstant* instr) {
+  Register left = ToRegister(instr->InputAt(0));
+  Register result = ToRegister(instr->result());
+
+  Label done;
+  __ cmp(left, instr->hydrogen()->right());
+  __ mov(result, factory()->true_value());
+  __ j(equal, &done, Label::kNear);
+  __ mov(result, factory()->false_value());
+  __ bind(&done);
+}
+
+
+void LCodeGen::DoCmpWithConstantAndBranch(LCmpWithConstantAndBranch* instr) {
+  Register left = ToRegister(instr->InputAt(0));
+  int true_block = chunk_->LookupDestination(instr->true_block_id());
+  int false_block = chunk_->LookupDestination(instr->false_block_id());
+
+  __ cmp(left, instr->hydrogen()->right());
+  EmitBranch(true_block, false_block, equal);
+}
+
+
 void LCodeGen::DoIsNull(LIsNull* instr) {
   Register reg = ToRegister(instr->InputAt(0));
   Register result = ToRegister(instr->result());
@@ -2376,7 +2414,7 @@ void LCodeGen::DoLoadElements(LLoadElements* instr) {
   Register input = ToRegister(instr->InputAt(0));
   __ mov(result, FieldOperand(input, JSObject::kElementsOffset));
   if (FLAG_debug_code) {
-    Label done;
+    Label done, ok, fail;
     __ cmp(FieldOperand(result, HeapObject::kMapOffset),
            Immediate(factory()->fixed_array_map()));
     __ j(equal, &done, Label::kNear);
@@ -2386,11 +2424,19 @@ void LCodeGen::DoLoadElements(LLoadElements* instr) {
     Register temp((result.is(eax)) ? ebx : eax);
     __ push(temp);
     __ mov(temp, FieldOperand(result, HeapObject::kMapOffset));
-    __ movzx_b(temp, FieldOperand(temp, Map::kInstanceTypeOffset));
-    __ sub(Operand(temp), Immediate(FIRST_EXTERNAL_ARRAY_TYPE));
-    __ cmp(Operand(temp), Immediate(kExternalArrayTypeCount));
+    __ movzx_b(temp, FieldOperand(temp, Map::kBitField2Offset));
+    __ and_(temp, Map::kElementsKindMask);
+    __ shr(temp, Map::kElementsKindShift);
+    __ cmp(temp, JSObject::FAST_ELEMENTS);
+    __ j(equal, &ok, Label::kNear);
+    __ cmp(temp, JSObject::FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND);
+    __ j(less, &fail, Label::kNear);
+    __ cmp(temp, JSObject::LAST_EXTERNAL_ARRAY_ELEMENTS_KIND);
+    __ j(less_equal, &ok, Label::kNear);
+    __ bind(&fail);
+    __ Abort("Check for fast elements or pixel array failed.");
+    __ bind(&ok);
     __ pop(temp);
-    __ Check(below, "Check for fast elements or pixel array failed.");
     __ bind(&done);
   }
 }