1//===- VPlanTransforms.h - Utility VPlan to VPlan transforms --------------===//
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/// \file
10/// This file provides utility VPlan to VPlan transformations.
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_TRANSFORMS_VECTORIZE_VPLANTRANSFORMS_H
14#define LLVM_TRANSFORMS_VECTORIZE_VPLANTRANSFORMS_H
15
16#include "VPlan.h"
17#include "llvm/ADT/STLFunctionalExtras.h"
18
19namespace llvm {
20
21class InductionDescriptor;
22class Instruction;
23class PHINode;
24class ScalarEvolution;
25class Loop;
26class PredicatedScalarEvolution;
27class TargetLibraryInfo;
28
29struct VPlanTransforms {
30  /// Replaces the VPInstructions in \p Plan with corresponding
31  /// widen recipes.
32  static void
33  VPInstructionsToVPRecipes(Loop *OrigLoop, VPlanPtr &Plan,
34                            function_ref<const InductionDescriptor *(PHINode *)>
35                                GetIntOrFpInductionDescriptor,
36                            SmallPtrSetImpl<Instruction *> &DeadInstructions,
37                            ScalarEvolution &SE, const TargetLibraryInfo &TLI);
38
39  static bool sinkScalarOperands(VPlan &Plan);
40
41  /// Merge replicate regions in their successor region, if a replicate region
42  /// is connected to a successor replicate region with the same predicate by a
43  /// single, empty VPBasicBlock.
44  static bool mergeReplicateRegionsIntoSuccessors(VPlan &Plan);
45
46  /// Remove redundant VPBasicBlocks by merging them into their predecessor if
47  /// the predecessor has a single successor.
48  static bool mergeBlocksIntoPredecessors(VPlan &Plan);
49
50  /// Remove redundant casts of inductions.
51  ///
52  /// Such redundant casts are casts of induction variables that can be ignored,
53  /// because we already proved that the casted phi is equal to the uncasted phi
54  /// in the vectorized loop. There is no need to vectorize the cast - the same
55  /// value can be used for both the phi and casts in the vector loop.
56  static void removeRedundantInductionCasts(VPlan &Plan);
57
58  /// Try to replace VPWidenCanonicalIVRecipes with a widened canonical IV
59  /// recipe, if it exists.
60  static void removeRedundantCanonicalIVs(VPlan &Plan);
61
62  static void removeDeadRecipes(VPlan &Plan);
63
64  /// If any user of a VPWidenIntOrFpInductionRecipe needs scalar values,
65  /// provide them by building scalar steps off of the canonical scalar IV and
66  /// update the original IV's users. This is an optional optimization to reduce
67  /// the needs of vector extracts.
68  static void optimizeInductions(VPlan &Plan, ScalarEvolution &SE);
69
70  /// Remove redundant EpxandSCEVRecipes in \p Plan's entry block by replacing
71  /// them with already existing recipes expanding the same SCEV expression.
72  static void removeRedundantExpandSCEVRecipes(VPlan &Plan);
73
74  /// Optimize \p Plan based on \p BestVF and \p BestUF. This may restrict the
75  /// resulting plan to \p BestVF and \p BestUF.
76  static void optimizeForVFAndUF(VPlan &Plan, ElementCount BestVF,
77                                 unsigned BestUF,
78                                 PredicatedScalarEvolution &PSE);
79};
80
81} // namespace llvm
82
83#endif // LLVM_TRANSFORMS_VECTORIZE_VPLANTRANSFORMS_H
84