PredictableCodeSizeScope checks the expected size now.

src/arm/full-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 272 matching lines @@
       }
       VisitDeclarations(scope()->declarations());
     }
 
     { Comment cmnt(masm_, "[ Stack check");
       PrepareForBailoutForId(BailoutId::Declarations(), NO_REGISTERS);
       Label ok;
       __ LoadRoot(ip, Heap::kStackLimitRootIndex);
       __ cmp(sp, Operand(ip));
       __ b(hs, &ok);
-      PredictableCodeSizeScope predictable(masm_);
+      PredictableCodeSizeScope predictable(masm_, 2 * Assembler::kInstrSize);
       StackCheckStub stub;
       __ CallStub(&stub);
       __ bind(&ok);
     }
 
     { Comment cmnt(masm_, "[ Body");
       ASSERT(loop_depth() == 0);
       VisitStatements(function()->body());
       ASSERT(loop_depth() == 0);
     }
@@ skipping 57 matching lines @@
                    Max(1, distance / kBackEdgeDistanceUnit));
     }
     EmitProfilingCounterDecrement(weight);
     __ b(pl, &ok);
     InterruptStub stub;
     __ CallStub(&stub);
   } else {
     __ LoadRoot(ip, Heap::kStackLimitRootIndex);
     __ cmp(sp, Operand(ip));
     __ b(hs, &ok);
-    PredictableCodeSizeScope predictable(masm_);
+    PredictableCodeSizeScope predictable(masm_, 2 * Assembler::kInstrSize);
     StackCheckStub stub;
     __ CallStub(&stub);
   }
 
   // Record a mapping of this PC offset to the OSR id.  This is used to find
   // the AST id from the unoptimized code in order to use it as a key into
   // the deoptimization input data found in the optimized code.
   RecordStackCheck(stmt->OsrEntryId());
 
   if (FLAG_count_based_interrupts) {
@@ skipping 53 matching lines @@
     Label check_exit_codesize;
     masm_->bind(&check_exit_codesize);
 #endif
     // Make sure that the constant pool is not emitted inside of the return
     // sequence.
     { Assembler::BlockConstPoolScope block_const_pool(masm_);
       // Here we use masm_-> instead of the __ macro to avoid the code coverage
       // tool from instrumenting as we rely on the code size here.
       int32_t sp_delta = (info_->scope()->num_parameters() + 1) * kPointerSize;
       CodeGenerator::RecordPositions(masm_, function()->end_position() - 1);
-      PredictableCodeSizeScope predictable(masm_);
+      // TODO(svenpanne) The code below is sometimes 4 words, sometimes 5!
+      PredictableCodeSizeScope predictable(masm_, -1);
       __ RecordJSReturn();
       masm_->mov(sp, fp);
       masm_->ldm(ia_w, sp, fp.bit() | lr.bit());
       masm_->add(sp, sp, Operand(sp_delta));
       masm_->Jump(lr);
     }
 
 #ifdef DEBUG
     // Check that the size of the code used for returning is large enough
     // for the debugger's requirements.
@@ skipping 4072 matching lines @@
   *context_length = 0;
   return previous_;
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM