ARM: Implement HasInstanceType in lithium backend.

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index 6d360e0799225846209cbfdcb5a3efe89dc51209..8e783d91fa53fdfc7726fd91c62cbaea40069c0c 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -1756,8 +1756,38 @@ Condition LHasInstanceType::BranchCondition() {
 }
 
 
+static InstanceType TestType(HHasInstanceType* instr) {
+  InstanceType from = instr->from();
+  InstanceType to = instr->to();
+  if (from == FIRST_TYPE) return to;
+  ASSERT(from == to || to == LAST_TYPE);
+  return from;
+}
+
+
+static Condition BranchCondition(HHasInstanceType* instr) {
+  InstanceType from = instr->from();
+  InstanceType to = instr->to();
+  if (from == to) return eq;
+  if (to == LAST_TYPE) return hs;
+  if (from == FIRST_TYPE) return ls;
+  UNREACHABLE();
+  return eq;
+}
+
+
 void LCodeGen::DoHasInstanceType(LHasInstanceType* instr) {
-  Abort("DoHasInstanceType unimplemented.");
+  Register input = ToRegister(instr->input());
+  Register result = ToRegister(instr->result());
+
+  ASSERT(instr->hydrogen()->value()->representation().IsTagged());
+  __ tst(input, Operand(kSmiTagMask));
+  Label done, is_false;

[Søren Thygesen Gjesse, 2011/01/19 12:55:00]

done currently not used.

+  __ b(eq, &is_false);

[Søren Thygesen Gjesse, 2011/01/19 12:55:00]

There is a JumpIfSmi in ARM macro assembler.

But, is_false is not bound, how about

__ LoadRoot(result, Heap::kFalseValueRootIndex, eq);
__ b(eq, &done);

(then JumpIfSmi cannot be used).

+  __ CompareObjectType(input, result, result, TestType(instr->hydrogen()));
+  Condition cond = BranchCondition(instr->hydrogen());
+  __ LoadRoot(result, Heap::kTrueValueRootIndex, cond);
+  __ LoadRoot(result, Heap::kFalseValueRootIndex, NegateCondition(cond));
 }