ARM: Implement DoIsObject and DoIsObjectAndBranch in the lithium code generator..

src/arm/lithium-codegen-arm.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1711 matching lines @@
     EmitBranch(true_block, false_block, ne);
   }
 }
 
 
 Condition LCodeGen::EmitIsObject(Register input,
                                  Register temp1,
                                  Register temp2,
                                  Label* is_not_object,
                                  Label* is_object) {
-  Abort("EmitIsObject unimplemented.");
-  return ne;
+  __ BranchOnSmi(input, is_not_object);
+
+  __ LoadRoot(temp1, Heap::kNullValueRootIndex);
+  __ cmp(input, temp1);
+  __ b(eq, is_object);
+
+  __ ldr(temp1, FieldMemOperand(input, HeapObject::kMapOffset));
+  __ ldrb(temp2, FieldMemOperand(temp1, Map::kBitFieldOffset));
+  __ tst(temp2, Operand(1 << Map::kIsUndetectable));
+  __ b(ne, is_not_object);
+
+  __ ldrb(temp2, FieldMemOperand(temp1, Map::kInstanceTypeOffset));
+  __ cmp(temp2, Operand(FIRST_JS_OBJECT_TYPE));
+  __ b(lt, is_not_object);
+  __ cmp(temp2, Operand(LAST_JS_OBJECT_TYPE));
+  return gt;

[Rodolph Perfetta, 2011/01/21 09:26:21]

Shouldn't it return le (lower or equal)?

[Karl Klose, 2011/01/21 18:04:09]

Done.

 }
 
 
 void LCodeGen::DoIsObject(LIsObject* instr) {
-  Abort("DoIsObject unimplemented.");
+  Register reg = ToRegister(instr->input());
+  Register result = ToRegister(instr->result());
+  Register temp = scratch0();
+  Label is_false, is_true, done;
+
+  Condition true_cond = EmitIsObject(reg, result, temp, &is_false, &is_true);
+  __ b(true_cond, &is_true);
+
+  __ bind(&is_false);
+  __ LoadRoot(result, Heap::kFalseValueRootIndex);
+  __ b(al, &done);
+
+  __ bind(&is_true);
+  __ LoadRoot(result, Heap::kTrueValueRootIndex, true_cond);

[Rodolph Perfetta, 2011/01/21 09:26:21]

The condition is unnecessary, you only jump here if it is true.

Alternatively you can write:
LoadRoot(result, Heap::kFalseValueRootIndex, NegateCondition(true_cond));
LoadRoot(result, Heap::kFalseValueRootIndex, true_cond);
Then you don't need the branches.

[Karl Klose, 2011/01/21 18:04:09]

I removed the condition.

It was a leftover from writing the code in the form you propose. The problem is
that EmitIsObject may directly jump to the labels provided, so I decided to keep
the labels.
On 2011/01/21 09:26:21, Rodolph Perfetta wrote:

+
+  __ bind(&done);
 }
 
 
 void LCodeGen::DoIsObjectAndBranch(LIsObjectAndBranch* instr) {
-  Abort("DoIsObjectAndBranch unimplemented.");
+  Register reg = ToRegister(instr->input());
+  Register temp1 = ToRegister(instr->temp());
+  Register temp2 = scratch0();
+
+  int true_block = chunk_->LookupDestination(instr->true_block_id());
+  int false_block = chunk_->LookupDestination(instr->false_block_id());
+  Label* true_label = chunk_->GetAssemblyLabel(true_block);
+  Label* false_label = chunk_->GetAssemblyLabel(false_block);
+
+  Condition true_cond = EmitIsObject(reg, temp1, temp2, false_label, true_label);

[Søren Thygesen Gjesse, 2011/01/21 07:38:13]

Long line.

[Karl Klose, 2011/01/21 18:04:09]

Done.

+
+  EmitBranch(true_block, false_block, true_cond);
 }
 
 
 void LCodeGen::DoIsSmi(LIsSmi* instr) {
   ASSERT(instr->hydrogen()->value()->representation().IsTagged());
   Register result = ToRegister(instr->result());
   Register input_reg = EmitLoadRegister(instr->input(), ip);
   __ tst(input_reg, Operand(kSmiTagMask));
   __ LoadRoot(result, Heap::kTrueValueRootIndex);
   Label done;
@@ skipping 1878 matching lines @@
 
 
 void LCodeGen::DoOsrEntry(LOsrEntry* instr) {
   Abort("DoOsrEntry unimplemented.");
 }
 
 
 #undef __
 
 } }  // namespace v8::internal