Use the information from the last recorded safepoint for the padding after the deferrred code.

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 239 matching lines @@
   if (current_instruction_ < instructions_->length() - 1) {
     return instructions_->at(current_instruction_ + 1);
   } else {
     return NULL;
   }
 }
 
 
 bool LCodeGen::GenerateDeferredCode() {
   ASSERT(is_generating());
-  Label last_jump;
   if (deferred_.length() > 0) {
     for (int i = 0; !is_aborted() && i < deferred_.length(); i++) {
       LDeferredCode* code = deferred_[i];
       __ bind(code->entry());
       code->Generate();
-#ifdef DEBUG
-      if (i == deferred_.length() - 1) {
-        __ bind(&last_jump);
-      }
-#endif
       __ jmp(code->exit());
     }
 
-    // Reserve some space to ensure that the last piece of deferred code
-    // have room for lazy bailout.
-    __ nop();
-    __ nop();
-
-    int code_generated =
-        masm_->InstructionsGeneratedSince(&last_jump) * Assembler::kInstrSize;
-    ASSERT(Deoptimizer::patch_size() <= code_generated);
-    USE(code_generated);
+    // Pad code to ensure that the last piece of deferred code have
+    // room for lazy bailout.
+    while ((masm()->pc_offset() - LastSafepointEnd())
+           < Deoptimizer::patch_size()) {
+      __ nop();
+    }
   }
 
   // Force constant pool emission at the end of the deferred code to make
   // sure that no constant pools are emitted after.
   masm()->CheckConstPool(true, false);
 
   return !is_aborted();
 }
 
 
@@ skipping 4108 matching lines @@
   ASSERT(osr_pc_offset_ == -1);
   osr_pc_offset_ = masm()->pc_offset();
 }
 
 
 
 
 #undef __
 
 } }  // namespace v8::internal