Lazy deopt without code patching.

runtime/vm/stub_code_mips.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_MIPS)
 
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
 #include "vm/compiler.h"
@@ skipping 529 matching lines @@
     __ Pop(V1);  // Restore stacktrace.
     __ Pop(V0);  // Restore exception.
   }
   __ LeaveStubFrame();
   // Remove materialization arguments.
   __ SmiUntag(T1);
   __ addu(SP, SP, T1);
   __ Ret();
 }
 
-// RA: return address + call-instruction-size
 // V0: result, must be preserved
 void StubCode::GenerateDeoptimizeLazyFromReturnStub(Assembler* assembler) {
-  // Correct return address to point just after the call that is being
-  // deoptimized.
-  __ AddImmediate(RA, -CallPattern::kDeoptCallLengthInBytes);
   // Push zap value instead of CODE_REG for lazy deopt.
   __ LoadImmediate(TMP, 0xf1f1f1f1);
   __ Push(TMP);
+  // Return address for "call" to deopt stub.
+  __ LoadImmediate(RA, 0xe1e1e1e1);
+  __ lw(CODE_REG, Address(THR, Thread::lazy_deopt_from_return_stub_offset()));
   GenerateDeoptimizationSequence(assembler, kLazyDeoptFromReturn);
 }
 
 
-// RA: return address + call-instruction-size
 // V0: exception, must be preserved
 // V1: stacktrace, must be preserved
 void StubCode::GenerateDeoptimizeLazyFromThrowStub(Assembler* assembler) {
-  // Correct return address to point just after the call that is being
-  // deoptimized.
-  __ AddImmediate(RA, -CallPattern::kDeoptCallLengthInBytes);
   // Push zap value instead of CODE_REG for lazy deopt.
   __ LoadImmediate(TMP, 0xf1f1f1f1);
   __ Push(TMP);
+  // Return address for "call" to deopt stub.
+  __ LoadImmediate(RA, 0xe1e1e1e1);
+  __ lw(CODE_REG, Address(THR, Thread::lazy_deopt_from_throw_stub_offset()));
   GenerateDeoptimizationSequence(assembler, kLazyDeoptFromThrow);
 }
 
 
 void StubCode::GenerateDeoptimizeStub(Assembler* assembler) {
   GenerateDeoptimizationSequence(assembler, kEagerDeopt);
 }
 
 
 static void GenerateDispatcherCode(Assembler* assembler,
@@ skipping 1808 matching lines @@
 }
 
 
 void StubCode::GenerateFrameAwaitingMaterializationStub(Assembler* assembler) {
   __ break_(0);
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS