Fix delta computation in DoDeferredInstanceOfKnownGlobal() for ARM.

src/arm/lithium-codegen-arm.cc

 // Copyright 2012 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 2454 matching lines @@
   InstanceofStub stub(flags);
 
   PushSafepointRegistersScope scope(this, Safepoint::kWithRegisters);
 
   // Get the temp register reserved by the instruction. This needs to be r4 as
   // its slot of the pushing of safepoint registers is used to communicate the
   // offset to the location of the map check.
   Register temp = ToRegister(instr->TempAt(0));
   ASSERT(temp.is(r4));
   __ LoadHeapObject(InstanceofStub::right(), instr->function());
-  static const int kAdditionalDelta = 4;
+  static const int kAdditionalDelta = 5;
   int delta = masm_->InstructionsGeneratedSince(map_check) + kAdditionalDelta;
   Label before_push_delta;
   __ bind(&before_push_delta);
   __ BlockConstPoolFor(kAdditionalDelta);
   __ mov(temp, Operand(delta * kPointerSize));
+  // The mov above can generate one or two instructions. The delta was computed
+  // for two instructions, so we need to pad here in case of one instruction.
+  if (masm_->InstructionsGeneratedSince(&before_push_delta) != 2) {

[Yang, 2012/09/11 10:54:50]

Maybe add an assert that InstructionsGeneratedSince(&before_push_delta) == 1 in
this case.

+    __ nop();
+  }
   __ StoreToSafepointRegisterSlot(temp, temp);
   CallCodeGeneric(stub.GetCode(),
                   RelocInfo::CODE_TARGET,
                   instr,
                   RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS);
   LEnvironment* env = instr->GetDeferredLazyDeoptimizationEnvironment();
   safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());
   // Put the result value into the result register slot and
   // restore all registers.
   __ StoreToSafepointRegisterSlot(result, result);
@@ skipping 3127 matching lines @@
   __ sub(scratch, result, Operand(index, LSL, kPointerSizeLog2 - kSmiTagSize));
   __ ldr(result, FieldMemOperand(scratch,
                                  FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal