Files
archived-llvm/include/llvm/Transforms/Scalar/LoopStrengthReduce.h
Chandler Carruth c68d25fb58 [PM] Separate the LoopAnalysisManager from the LoopPassManager and move
the latter to the Transforms library.

While the loop PM uses an analysis to form the IR units, the current
plan is to have the PM itself establish and enforce both loop simplified
form and LCSSA. This would be a layering violation in the analysis
library.

Fundamentally, the idea behind the loop PM is to *transform* loops in
addition to running passes over them, so it really seemed like the most
natural place to sink this was into the transforms library.

We can't just move *everything* because we also have loop analyses that
rely on a subset of the invariants. So this patch splits the the loop
infrastructure into the analysis management that has to be part of the
analysis library, and the transform-aware pass manager.

This also required splitting the loop analyses' printer passes out to
the transforms library, which makes sense to me as running these will
transform the code into LCSSA in theory.

I haven't split the unittest though because testing one component
without the other seems nearly intractable.

Differential Revision: https://reviews.llvm.org/D28452

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291662 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-11 09:43:56 +00:00

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//===- LoopStrengthReduce.h - Loop Strength Reduce Pass -------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This transformation analyzes and transforms the induction variables (and
// computations derived from them) into forms suitable for efficient execution
// on the target.
//
// This pass performs a strength reduction on array references inside loops that
// have as one or more of their components the loop induction variable, it
// rewrites expressions to take advantage of scaled-index addressing modes
// available on the target, and it performs a variety of other optimizations
// related to loop induction variables.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_TRANSFORMS_SCALAR_LOOPSTRENGTHREDUCE_H
#define LLVM_TRANSFORMS_SCALAR_LOOPSTRENGTHREDUCE_H
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/IR/PassManager.h"
#include "llvm/Transforms/Scalar/LoopPassManager.h"
namespace llvm {
/// Performs Loop Strength Reduce Pass.
class LoopStrengthReducePass : public PassInfoMixin<LoopStrengthReducePass> {
public:
PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM,
LoopStandardAnalysisResults &AR, LPMUpdater &U);
};
} // end namespace llvm
#endif // LLVM_TRANSFORMS_SCALAR_LOOPSTRENGTHREDUCE_H