Lazy deopt without code patching.

runtime/vm/stub_code_ia32.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_IA32)
 
 #include "vm/assembler.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
@@ skipping 443 matching lines @@
   }
   __ LeaveFrame();
 
   __ popl(ECX);  // Pop return address.
   __ addl(ESP, EBX);  // Remove materialization arguments.
   __ pushl(ECX);  // Push return address.
   __ ret();
 }
 
 
-// TOS: return address + call-instruction-size (5 bytes).
 // EAX: result, must be preserved
 void StubCode::GenerateDeoptimizeLazyFromReturnStub(Assembler* assembler) {
-  // Correct return address to point just after the call that is being
-  // deoptimized.
-  __ popl(EBX);
-  __ subl(EBX, Immediate(CallPattern::pattern_length_in_bytes()));
-  __ pushl(EBX);
+  // Return address for "call" to deopt stub.
+  __ pushl(Immediate(0xe1e1e1e1));
   GenerateDeoptimizationSequence(assembler, kLazyDeoptFromReturn);
 }
 
 
-// TOS: return address + call-instruction-size (5 bytes).
 // EAX: exception, must be preserved
 // EDX: stacktrace, must be preserved
 void StubCode::GenerateDeoptimizeLazyFromThrowStub(Assembler* assembler) {
-  // Correct return address to point just after the call that is being
-  // deoptimized.
-  __ popl(EBX);
-  __ subl(EBX, Immediate(CallPattern::pattern_length_in_bytes()));
-  __ pushl(EBX);
+  // Return address for "call" to deopt stub.
+  __ pushl(Immediate(0xe1e1e1e1));
   GenerateDeoptimizationSequence(assembler, kLazyDeoptFromThrow);
 }
 
 
 void StubCode::GenerateDeoptimizeStub(Assembler* assembler) {
   GenerateDeoptimizationSequence(assembler, kEagerDeopt);
 }
 
 
 static void GenerateDispatcherCode(Assembler* assembler,
@@ skipping 1577 matching lines @@
 }
 
 
 void StubCode::GenerateFrameAwaitingMaterializationStub(Assembler* assembler) {
   __ int3();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32