66 lines · cpp
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-exception6//7//===----------------------------------------------------------------------===//8//9// This file implements loop invariant code motion.10//11//===----------------------------------------------------------------------===//12 13#include "mlir/Transforms/Passes.h"14 15#include "mlir/IR/PatternMatch.h"16#include "mlir/Interfaces/LoopLikeInterface.h"17#include "mlir/Transforms/LoopInvariantCodeMotionUtils.h"18 19namespace mlir {20#define GEN_PASS_DEF_LOOPINVARIANTCODEMOTION21#define GEN_PASS_DEF_LOOPINVARIANTSUBSETHOISTING22#include "mlir/Transforms/Passes.h.inc"23} // namespace mlir24 25using namespace mlir;26 27namespace {28/// Loop invariant code motion (LICM) pass.29struct LoopInvariantCodeMotion30 : public impl::LoopInvariantCodeMotionBase<LoopInvariantCodeMotion> {31 void runOnOperation() override;32};33 34struct LoopInvariantSubsetHoisting35 : public impl::LoopInvariantSubsetHoistingBase<36 LoopInvariantSubsetHoisting> {37 void runOnOperation() override;38};39} // namespace40 41void LoopInvariantCodeMotion::runOnOperation() {42 // Walk through all loops in a function in innermost-loop-first order. This43 // way, we first LICM from the inner loop, and place the ops in44 // the outer loop, which in turn can be further LICM'ed.45 getOperation()->walk(46 [&](LoopLikeOpInterface loopLike) { moveLoopInvariantCode(loopLike); });47}48 49void LoopInvariantSubsetHoisting::runOnOperation() {50 IRRewriter rewriter(getOperation()->getContext());51 // Walk through all loops in a function in innermost-loop-first order. This52 // way, we first hoist from the inner loop, and place the ops in the outer53 // loop, which in turn can be further hoisted from.54 getOperation()->walk([&](LoopLikeOpInterface loopLike) {55 (void)hoistLoopInvariantSubsets(rewriter, loopLike);56 });57}58 59std::unique_ptr<Pass> mlir::createLoopInvariantCodeMotionPass() {60 return std::make_unique<LoopInvariantCodeMotion>();61}62 63std::unique_ptr<Pass> mlir::createLoopInvariantSubsetHoistingPass() {64 return std::make_unique<LoopInvariantSubsetHoisting>();65}66