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, bool frame_at_start); 22 23 // Rewrite the instructions to forward jumps and branches. 24 // May also negate some branches. 25 static void ApplyForwarding(Zone* local_zone, 26 ZoneVector<RpoNumber>& forwarding, 27 InstructionSequence* code); 28 }; 29 30 } // namespace compiler 31 } // namespace internal 32 } // namespace v8 33 34 #endif // V8_COMPILER_JUMP_THREADING_H_ 35