MLIR  16.0.0git
LoopInvariantCodeMotion.cpp
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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 
18 
19 namespace mlir {
20 #define GEN_PASS_DEF_LOOPINVARIANTCODEMOTION
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 LoopInvariantCodeMotion
29  : public impl::LoopInvariantCodeMotionBase<LoopInvariantCodeMotion> {
30  void runOnOperation() override;
31 };
32 } // namespace
33 
34 void LoopInvariantCodeMotion::runOnOperation() {
35  // Walk through all loops in a function in innermost-loop-first order. This
36  // way, we first LICM from the inner loop, and place the ops in
37  // the outer loop, which in turn can be further LICM'ed.
38  getOperation()->walk(
39  [&](LoopLikeOpInterface loopLike) { moveLoopInvariantCode(loopLike); });
40 }
41 
42 std::unique_ptr<Pass> mlir::createLoopInvariantCodeMotionPass() {
43  return std::make_unique<LoopInvariantCodeMotion>();
44 }
Include the generated interface declarations.
std::unique_ptr< Pass > createLoopInvariantCodeMotionPass()
Creates a loop invariant code motion pass that hoists loop invariant instructions out of the loop.
size_t moveLoopInvariantCode(RegionRange regions, function_ref< bool(Value, Region *)> isDefinedOutsideRegion, function_ref< bool(Operation *, Region *)> shouldMoveOutOfRegion, function_ref< void(Operation *, Region *)> moveOutOfRegion)
Given a list of regions, perform loop-invariant code motion.