Florian Hahn 89718815c6
[VPlan] Adjust mergeReplicateRegions to be in line with mergeBlock (NFC)
Adjust mergeReplicateRegions to be in line with
mergeBlocksIntoPredecessors added in 36d70a6aea6b by collecting only the
valid candidates first.

Also rename to mergeReplicateRegionsIntoSuccessors and add missing
doc-comment.

This addresses post-commit suggestions by @Ayal.
2023-01-01 19:48:49 +00:00

84 lines
3.3 KiB
C++

//===- VPlanTransforms.h - Utility VPlan to VPlan transforms --------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
///
/// \file
/// This file provides utility VPlan to VPlan transformations.
//===----------------------------------------------------------------------===//
#ifndef LLVM_TRANSFORMS_VECTORIZE_VPLANTRANSFORMS_H
#define LLVM_TRANSFORMS_VECTORIZE_VPLANTRANSFORMS_H
#include "VPlan.h"
#include "llvm/ADT/STLFunctionalExtras.h"
namespace llvm {
class InductionDescriptor;
class Instruction;
class PHINode;
class ScalarEvolution;
class Loop;
class PredicatedScalarEvolution;
class TargetLibraryInfo;
struct VPlanTransforms {
/// Replaces the VPInstructions in \p Plan with corresponding
/// widen recipes.
static void
VPInstructionsToVPRecipes(Loop *OrigLoop, VPlanPtr &Plan,
function_ref<const InductionDescriptor *(PHINode *)>
GetIntOrFpInductionDescriptor,
SmallPtrSetImpl<Instruction *> &DeadInstructions,
ScalarEvolution &SE, const TargetLibraryInfo &TLI);
static bool sinkScalarOperands(VPlan &Plan);
/// Merge replicate regions in their successor region, if a replicate region
/// is connected to a successor replicate region with the same predicate by a
/// single, empty VPBasicBlock.
static bool mergeReplicateRegionsIntoSuccessors(VPlan &Plan);
/// Remove redundant VPBasicBlocks by merging them into their predecessor if
/// the predecessor has a single successor.
static bool mergeBlocksIntoPredecessors(VPlan &Plan);
/// Remove redundant casts of inductions.
///
/// Such redundant casts are casts of induction variables that can be ignored,
/// because we already proved that the casted phi is equal to the uncasted phi
/// in the vectorized loop. There is no need to vectorize the cast - the same
/// value can be used for both the phi and casts in the vector loop.
static void removeRedundantInductionCasts(VPlan &Plan);
/// Try to replace VPWidenCanonicalIVRecipes with a widened canonical IV
/// recipe, if it exists.
static void removeRedundantCanonicalIVs(VPlan &Plan);
static void removeDeadRecipes(VPlan &Plan);
/// If any user of a VPWidenIntOrFpInductionRecipe needs scalar values,
/// provide them by building scalar steps off of the canonical scalar IV and
/// update the original IV's users. This is an optional optimization to reduce
/// the needs of vector extracts.
static void optimizeInductions(VPlan &Plan, ScalarEvolution &SE);
/// Remove redundant EpxandSCEVRecipes in \p Plan's entry block by replacing
/// them with already existing recipes expanding the same SCEV expression.
static void removeRedundantExpandSCEVRecipes(VPlan &Plan);
/// Optimize \p Plan based on \p BestVF and \p BestUF. This may restrict the
/// resulting plan to \p BestVF and \p BestUF.
static void optimizeForVFAndUF(VPlan &Plan, ElementCount BestVF,
unsigned BestUF,
PredicatedScalarEvolution &PSE);
};
} // namespace llvm
#endif // LLVM_TRANSFORMS_VECTORIZE_VPLANTRANSFORMS_H