Merge r8237 to V8 3.2 branch. Fix bug v8:1434, optimized compare of undefined can fail.

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 3542 matching lines @@
   if (instr->needs_check()) {
     __ tst(ToRegister(input), Operand(kSmiTagMask));
     DeoptimizeIf(ne, instr->environment());
   }
   __ SmiUntag(ToRegister(input));
 }
 
 
 void LCodeGen::EmitNumberUntagD(Register input_reg,
                                 DoubleRegister result_reg,
+                                bool deoptimize_on_undefined,
                                 LEnvironment* env) {
   Register scratch = scratch0();
   SwVfpRegister flt_scratch = s0;
   ASSERT(!result_reg.is(d0));
 
   Label load_smi, heap_number, done;
 
   // Smi check.
   __ tst(input_reg, Operand(kSmiTagMask));
   __ b(eq, &load_smi);
 
   // Heap number map check.
   __ ldr(scratch, FieldMemOperand(input_reg, HeapObject::kMapOffset));
   __ LoadRoot(ip, Heap::kHeapNumberMapRootIndex);
   __ cmp(scratch, Operand(ip));
-  __ b(eq, &heap_number);
+  if (deoptimize_on_undefined) {
+    DeoptimizeIf(ne, env);
+  } else {
+    Label heap_number;
+    __ b(eq, &heap_number);
 
-  __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
-  __ cmp(input_reg, Operand(ip));
-  DeoptimizeIf(ne, env);
+    __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
+    __ cmp(input_reg, Operand(ip));
+    DeoptimizeIf(ne, env);
 
-  // Convert undefined to NaN.
-  __ LoadRoot(ip, Heap::kNanValueRootIndex);
-  __ sub(ip, ip, Operand(kHeapObjectTag));
-  __ vldr(result_reg, ip, HeapNumber::kValueOffset);
-  __ jmp(&done);
+    // Convert undefined to NaN.
+    __ LoadRoot(ip, Heap::kNanValueRootIndex);
+    __ sub(ip, ip, Operand(kHeapObjectTag));
+    __ vldr(result_reg, ip, HeapNumber::kValueOffset);
+    __ jmp(&done);
 
+    __ bind(&heap_number);
+  }
   // Heap number to double register conversion.
-  __ bind(&heap_number);
   __ sub(ip, input_reg, Operand(kHeapObjectTag));
   __ vldr(result_reg, ip, HeapNumber::kValueOffset);
   __ jmp(&done);
 
   // Smi to double register conversion
   __ bind(&load_smi);
   __ SmiUntag(input_reg);  // Untag smi before converting to float.
   __ vmov(flt_scratch, input_reg);
   __ vcvt_f64_s32(result_reg, flt_scratch);
   __ SmiTag(input_reg);  // Retag smi.
@@ skipping 108 matching lines @@
 
 void LCodeGen::DoNumberUntagD(LNumberUntagD* instr) {
   LOperand* input = instr->InputAt(0);
   ASSERT(input->IsRegister());
   LOperand* result = instr->result();
   ASSERT(result->IsDoubleRegister());
 
   Register input_reg = ToRegister(input);
   DoubleRegister result_reg = ToDoubleRegister(result);
 
-  EmitNumberUntagD(input_reg, result_reg, instr->environment());
+  EmitNumberUntagD(input_reg, result_reg,
+                   instr->hydrogen()->deoptimize_on_undefined(),
+                   instr->environment());
 }
 
 
 void LCodeGen::DoDoubleToI(LDoubleToI* instr) {
   Register result_reg = ToRegister(instr->result());
   Register scratch1 = scratch0();
   Register scratch2 = ToRegister(instr->TempAt(0));
   DwVfpRegister double_input = ToDoubleRegister(instr->InputAt(0));
   DwVfpRegister double_scratch = double_scratch0();
   SwVfpRegister single_scratch = double_scratch0().low();
@@ skipping 467 matching lines @@
   ASSERT(!environment->HasBeenRegistered());
   RegisterEnvironmentForDeoptimization(environment);
   ASSERT(osr_pc_offset_ == -1);
   osr_pc_offset_ = masm()->pc_offset();
 }
 
 
 #undef __
 
 } }  // namespace v8::internal