1 //===- LoopInvariantCodeMotion.cpp - Code to perform loop fusion-----------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file implements loop invariant code motion. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "mlir/Transforms/Passes.h" 14 15 #include "mlir/Interfaces/LoopLikeInterface.h" 16 #include "mlir/Transforms/LoopInvariantCodeMotionUtils.h" 17 #include "mlir/Transforms/SideEffectUtils.h" 18 19 namespace mlir { 20 #define GEN_PASS_DEF_LOOPINVARIANTCODEMOTIONPASS 21 #include "mlir/Transforms/Passes.h.inc" 22 } // namespace mlir 23 24 using namespace mlir; 25 26 namespace { 27 /// Loop invariant code motion (LICM) pass. 28 struct LoopInvariantCodeMotionPass 29 : public impl::LoopInvariantCodeMotionPassBase< 30 LoopInvariantCodeMotionPass> { 31 using LoopInvariantCodeMotionPassBase::LoopInvariantCodeMotionPassBase; 32 33 void runOnOperation() override; 34 }; 35 } // namespace 36 37 void LoopInvariantCodeMotionPass::runOnOperation() { 38 // Walk through all loops in a function in innermost-loop-first order. This 39 // way, we first LICM from the inner loop, and place the ops in 40 // the outer loop, which in turn can be further LICM'ed. 41 getOperation()->walk( 42 [&](LoopLikeOpInterface loopLike) { moveLoopInvariantCode(loopLike); }); 43 } 44