|  | // Copyright 2014 the V8 project authors. All rights reserved. | 
|  | // Use of this source code is governed by a BSD-style license that can be | 
|  | // found in the LICENSE file. | 
|  |  | 
|  | #ifndef V8_COMPILER_JUMP_THREADING_H_ | 
|  | #define V8_COMPILER_JUMP_THREADING_H_ | 
|  |  | 
|  | #include "src/compiler/instruction.h" | 
|  |  | 
|  | namespace v8 { | 
|  | namespace internal { | 
|  | namespace compiler { | 
|  |  | 
|  | // Forwards jumps to empty basic blocks that end with a second jump to the | 
|  | // destination of the second jump, transitively. | 
|  | class JumpThreading { | 
|  | public: | 
|  | // Compute the forwarding map of basic blocks to their ultimate destination. | 
|  | // Returns {true} if there is at least one block that is forwarded. | 
|  | static bool ComputeForwarding(Zone* local_zone, ZoneVector<RpoNumber>& result, | 
|  | InstructionSequence* code, bool frame_at_start); | 
|  |  | 
|  | // Rewrite the instructions to forward jumps and branches. | 
|  | // May also negate some branches. | 
|  | static void ApplyForwarding(ZoneVector<RpoNumber>& forwarding, | 
|  | InstructionSequence* code); | 
|  | }; | 
|  |  | 
|  | }  // namespace compiler | 
|  | }  // namespace internal | 
|  | }  // namespace v8 | 
|  |  | 
|  | #endif  // V8_COMPILER_JUMP_THREADING_H |