1 // Copyright 2014 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef V8_COMPILER_JUMP_THREADING_H_
6 #define V8_COMPILER_JUMP_THREADING_H_
7 
8 #include "src/compiler/instruction.h"
9 
10 namespace v8 {
11 namespace internal {
12 namespace compiler {
13 
14 // Forwards jumps to empty basic blocks that end with a second jump to the
15 // destination of the second jump, transitively.
16 class JumpThreading {
17  public:
18   // Compute the forwarding map of basic blocks to their ultimate destination.
19   // Returns {true} if there is at least one block that is forwarded.
20   static bool ComputeForwarding(Zone* local_zone, ZoneVector<RpoNumber>& result,
21                                 InstructionSequence* code);
22 
23   // Rewrite the instructions to forward jumps and branches.
24   // May also negate some branches.
25   static void ApplyForwarding(ZoneVector<RpoNumber>& forwarding,
26                               InstructionSequence* code);
27 };
28 
29 }  // namespace compiler
30 }  // namespace internal
31 }  // namespace v8
32 
33 #endif  // V8_COMPILER_JUMP_THREADING_H
34