Avoid patching code after the call to binary operation stub in optimized code

src/arm/lithium-codegen-arm.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
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 // modification, are permitted provided that the following conditions are
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 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
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@@ skipping 533 matching lines @@
 
 void LCodeGen::CallCodeGeneric(Handle<Code> code,
                                RelocInfo::Mode mode,
                                LInstruction* instr,
                                SafepointMode safepoint_mode) {
   ASSERT(instr != NULL);
   LPointerMap* pointers = instr->pointer_map();
   RecordPosition(pointers->position());
   __ Call(code, mode);
   RegisterLazyDeoptimization(instr, safepoint_mode);
+
+  // Signal that we don't inline smi code before these stubs in the
+  // optimizing code generator.
+  if (code->kind() == Code::BINARY_OP_IC ||
+      code->kind() == Code::COMPARE_IC) {
+    __ nop();
+  }
 }
 
 
 void LCodeGen::CallRuntime(const Runtime::Function* function,
                            int num_arguments,
                            LInstruction* instr) {
   ASSERT(instr != NULL);
   LPointerMap* pointers = instr->pointer_map();
   ASSERT(pointers != NULL);
   RecordPosition(pointers->position());
@@ skipping 935 matching lines @@
 }
 
 
 void LCodeGen::DoArithmeticT(LArithmeticT* instr) {
   ASSERT(ToRegister(instr->InputAt(0)).is(r1));
   ASSERT(ToRegister(instr->InputAt(1)).is(r0));
   ASSERT(ToRegister(instr->result()).is(r0));
 
   BinaryOpStub stub(instr->op(), NO_OVERWRITE);
   CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
+  __ nop();  // Signals no inlined code.

[danno, 2011/07/13 08:11:10]

Is it at all possible to create something like CallBinaryOpStub to ensure that a
nop or the correct test always gets inserted? Seems like we should try to make
it very difficult to forget to insert the nop.

[Søren Thygesen Gjesse, 2011/07/13 09:26:15]

I am not sure, we already have special handling in CallCodeGeneric. The patch
which had regressions is probably the right way, and if we can find a faster way
to checking whether we are calling from optimized code or not it can all be
handled in the runtime performing the patch.

 }
 
 
 int LCodeGen::GetNextEmittedBlock(int block) {
   for (int i = block + 1; i < graph()->blocks()->length(); ++i) {
     LLabel* label = chunk_->GetLabel(i);
     if (!label->HasReplacement()) return i;
   }
   return -1;
 }
@@ skipping 2873 matching lines @@
   ASSERT(osr_pc_offset_ == -1);
   osr_pc_offset_ = masm()->pc_offset();
 }
 
 
 
 
 #undef __
 
 } }  // namespace v8::internal