3d42d54955
This patch is a first draft of a new pass that adds a more flexible way
to eliminate compares based on more complex constraints collected from
dominating conditions.
In particular, it aims at simplifying conditions of the forms below
using a forward propagation approach, rather than instcomine-style
ad-hoc backwards walking of def-use chains.
if (x < y)
if (y < z)
if (x < z) <- simplify
or
if (x + 2 < y)
if (x + 1 < y) <- simplify assuming no wraps
The general approach is to collect conditions and blocks, sort them by
dominance and then iterate over the sorted list. Conditions are turned
into a linear inequality and add it to a system containing the linear
inequalities that hold on entry to the block. For blocks, we check each
compare against the system and see if it is implied by the constraints
in the system.
We also keep a stack of processed conditions and remove conditions from
the stack and the constraint system once they go out-of-scope (= do not
dominate the current block any longer).
Currently there still are the least the following areas for improvements
* Currently large unsigned constants cannot be added to the system
(coefficients must be represented as integers)
* The way constraints are managed currently is not very optimized.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D84547
302 lines
10 KiB
C++
302 lines
10 KiB
C++
//===-- Scalar.cpp --------------------------------------------------------===//
|
|
//
|
|
// 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
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file implements common infrastructure for libLLVMScalarOpts.a, which
|
|
// implements several scalar transformations over the LLVM intermediate
|
|
// representation, including the C bindings for that library.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/Transforms/Scalar.h"
|
|
#include "llvm-c/Initialization.h"
|
|
#include "llvm-c/Transforms/Scalar.h"
|
|
#include "llvm/Analysis/BasicAliasAnalysis.h"
|
|
#include "llvm/Analysis/Passes.h"
|
|
#include "llvm/Analysis/ScopedNoAliasAA.h"
|
|
#include "llvm/Analysis/TypeBasedAliasAnalysis.h"
|
|
#include "llvm/IR/DataLayout.h"
|
|
#include "llvm/IR/LegacyPassManager.h"
|
|
#include "llvm/IR/Verifier.h"
|
|
#include "llvm/InitializePasses.h"
|
|
#include "llvm/Transforms/Scalar/GVN.h"
|
|
#include "llvm/Transforms/Scalar/Scalarizer.h"
|
|
#include "llvm/Transforms/Scalar/SimpleLoopUnswitch.h"
|
|
#include "llvm/Transforms/Utils/UnifyFunctionExitNodes.h"
|
|
|
|
using namespace llvm;
|
|
|
|
/// initializeScalarOptsPasses - Initialize all passes linked into the
|
|
/// ScalarOpts library.
|
|
void llvm::initializeScalarOpts(PassRegistry &Registry) {
|
|
initializeADCELegacyPassPass(Registry);
|
|
initializeBDCELegacyPassPass(Registry);
|
|
initializeAlignmentFromAssumptionsPass(Registry);
|
|
initializeCallSiteSplittingLegacyPassPass(Registry);
|
|
initializeConstantHoistingLegacyPassPass(Registry);
|
|
initializeConstraintEliminationPass(Registry);
|
|
initializeCorrelatedValuePropagationPass(Registry);
|
|
initializeDCELegacyPassPass(Registry);
|
|
initializeDeadInstEliminationPass(Registry);
|
|
initializeDivRemPairsLegacyPassPass(Registry);
|
|
initializeScalarizerLegacyPassPass(Registry);
|
|
initializeDSELegacyPassPass(Registry);
|
|
initializeGuardWideningLegacyPassPass(Registry);
|
|
initializeLoopGuardWideningLegacyPassPass(Registry);
|
|
initializeGVNLegacyPassPass(Registry);
|
|
initializeNewGVNLegacyPassPass(Registry);
|
|
initializeEarlyCSELegacyPassPass(Registry);
|
|
initializeEarlyCSEMemSSALegacyPassPass(Registry);
|
|
initializeMakeGuardsExplicitLegacyPassPass(Registry);
|
|
initializeGVNHoistLegacyPassPass(Registry);
|
|
initializeGVNSinkLegacyPassPass(Registry);
|
|
initializeFlattenCFGPassPass(Registry);
|
|
initializeIRCELegacyPassPass(Registry);
|
|
initializeIndVarSimplifyLegacyPassPass(Registry);
|
|
initializeInferAddressSpacesPass(Registry);
|
|
initializeInstSimplifyLegacyPassPass(Registry);
|
|
initializeJumpThreadingPass(Registry);
|
|
initializeLegacyLICMPassPass(Registry);
|
|
initializeLegacyLoopSinkPassPass(Registry);
|
|
initializeLoopFuseLegacyPass(Registry);
|
|
initializeLoopDataPrefetchLegacyPassPass(Registry);
|
|
initializeLoopDeletionLegacyPassPass(Registry);
|
|
initializeLoopAccessLegacyAnalysisPass(Registry);
|
|
initializeLoopInstSimplifyLegacyPassPass(Registry);
|
|
initializeLoopInterchangePass(Registry);
|
|
initializeLoopPredicationLegacyPassPass(Registry);
|
|
initializeLoopRotateLegacyPassPass(Registry);
|
|
initializeLoopStrengthReducePass(Registry);
|
|
initializeLoopRerollPass(Registry);
|
|
initializeLoopUnrollPass(Registry);
|
|
initializeLoopUnrollAndJamPass(Registry);
|
|
initializeLoopUnswitchPass(Registry);
|
|
initializeWarnMissedTransformationsLegacyPass(Registry);
|
|
initializeLoopVersioningLICMPass(Registry);
|
|
initializeLoopIdiomRecognizeLegacyPassPass(Registry);
|
|
initializeLowerAtomicLegacyPassPass(Registry);
|
|
initializeLowerConstantIntrinsicsPass(Registry);
|
|
initializeLowerExpectIntrinsicPass(Registry);
|
|
initializeLowerGuardIntrinsicLegacyPassPass(Registry);
|
|
initializeLowerMatrixIntrinsicsLegacyPassPass(Registry);
|
|
initializeLowerMatrixIntrinsicsMinimalLegacyPassPass(Registry);
|
|
initializeLowerWidenableConditionLegacyPassPass(Registry);
|
|
initializeMemCpyOptLegacyPassPass(Registry);
|
|
initializeMergeICmpsLegacyPassPass(Registry);
|
|
initializeMergedLoadStoreMotionLegacyPassPass(Registry);
|
|
initializeNaryReassociateLegacyPassPass(Registry);
|
|
initializePartiallyInlineLibCallsLegacyPassPass(Registry);
|
|
initializeReassociateLegacyPassPass(Registry);
|
|
initializeRedundantDbgInstEliminationPass(Registry);
|
|
initializeRegToMemPass(Registry);
|
|
initializeRewriteStatepointsForGCLegacyPassPass(Registry);
|
|
initializeSCCPLegacyPassPass(Registry);
|
|
initializeSROALegacyPassPass(Registry);
|
|
initializeCFGSimplifyPassPass(Registry);
|
|
initializeStructurizeCFGPass(Registry);
|
|
initializeSimpleLoopUnswitchLegacyPassPass(Registry);
|
|
initializeSinkingLegacyPassPass(Registry);
|
|
initializeTailCallElimPass(Registry);
|
|
initializeSeparateConstOffsetFromGEPPass(Registry);
|
|
initializeSpeculativeExecutionLegacyPassPass(Registry);
|
|
initializeStraightLineStrengthReducePass(Registry);
|
|
initializePlaceBackedgeSafepointsImplPass(Registry);
|
|
initializePlaceSafepointsPass(Registry);
|
|
initializeFloat2IntLegacyPassPass(Registry);
|
|
initializeLoopDistributeLegacyPass(Registry);
|
|
initializeLoopLoadEliminationPass(Registry);
|
|
initializeLoopSimplifyCFGLegacyPassPass(Registry);
|
|
initializeLoopVersioningLegacyPassPass(Registry);
|
|
initializeEntryExitInstrumenterPass(Registry);
|
|
initializePostInlineEntryExitInstrumenterPass(Registry);
|
|
}
|
|
|
|
void LLVMAddLoopSimplifyCFGPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createLoopSimplifyCFGPass());
|
|
}
|
|
|
|
void LLVMInitializeScalarOpts(LLVMPassRegistryRef R) {
|
|
initializeScalarOpts(*unwrap(R));
|
|
}
|
|
|
|
void LLVMAddAggressiveDCEPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createAggressiveDCEPass());
|
|
}
|
|
|
|
void LLVMAddDCEPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createDeadCodeEliminationPass());
|
|
}
|
|
|
|
void LLVMAddBitTrackingDCEPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createBitTrackingDCEPass());
|
|
}
|
|
|
|
void LLVMAddAlignmentFromAssumptionsPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createAlignmentFromAssumptionsPass());
|
|
}
|
|
|
|
void LLVMAddCFGSimplificationPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createCFGSimplificationPass());
|
|
}
|
|
|
|
void LLVMAddDeadStoreEliminationPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createDeadStoreEliminationPass());
|
|
}
|
|
|
|
void LLVMAddScalarizerPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createScalarizerPass());
|
|
}
|
|
|
|
void LLVMAddGVNPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createGVNPass());
|
|
}
|
|
|
|
void LLVMAddNewGVNPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createNewGVNPass());
|
|
}
|
|
|
|
void LLVMAddMergedLoadStoreMotionPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createMergedLoadStoreMotionPass());
|
|
}
|
|
|
|
void LLVMAddIndVarSimplifyPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createIndVarSimplifyPass());
|
|
}
|
|
|
|
void LLVMAddInstructionSimplifyPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createInstSimplifyLegacyPass());
|
|
}
|
|
|
|
void LLVMAddJumpThreadingPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createJumpThreadingPass());
|
|
}
|
|
|
|
void LLVMAddLoopSinkPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createLoopSinkPass());
|
|
}
|
|
|
|
void LLVMAddLICMPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createLICMPass());
|
|
}
|
|
|
|
void LLVMAddLoopDeletionPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createLoopDeletionPass());
|
|
}
|
|
|
|
void LLVMAddLoopIdiomPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createLoopIdiomPass());
|
|
}
|
|
|
|
void LLVMAddLoopRotatePass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createLoopRotatePass());
|
|
}
|
|
|
|
void LLVMAddLoopRerollPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createLoopRerollPass());
|
|
}
|
|
|
|
void LLVMAddLoopUnrollPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createLoopUnrollPass());
|
|
}
|
|
|
|
void LLVMAddLoopUnrollAndJamPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createLoopUnrollAndJamPass());
|
|
}
|
|
|
|
void LLVMAddLoopUnswitchPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createLoopUnswitchPass());
|
|
}
|
|
|
|
void LLVMAddLowerAtomicPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createLowerAtomicPass());
|
|
}
|
|
|
|
void LLVMAddMemCpyOptPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createMemCpyOptPass());
|
|
}
|
|
|
|
void LLVMAddPartiallyInlineLibCallsPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createPartiallyInlineLibCallsPass());
|
|
}
|
|
|
|
void LLVMAddReassociatePass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createReassociatePass());
|
|
}
|
|
|
|
void LLVMAddSCCPPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createSCCPPass());
|
|
}
|
|
|
|
void LLVMAddScalarReplAggregatesPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createSROAPass());
|
|
}
|
|
|
|
void LLVMAddScalarReplAggregatesPassSSA(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createSROAPass());
|
|
}
|
|
|
|
void LLVMAddScalarReplAggregatesPassWithThreshold(LLVMPassManagerRef PM,
|
|
int Threshold) {
|
|
unwrap(PM)->add(createSROAPass());
|
|
}
|
|
|
|
void LLVMAddSimplifyLibCallsPass(LLVMPassManagerRef PM) {
|
|
// NOTE: The simplify-libcalls pass has been removed.
|
|
}
|
|
|
|
void LLVMAddTailCallEliminationPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createTailCallEliminationPass());
|
|
}
|
|
|
|
void LLVMAddDemoteMemoryToRegisterPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createDemoteRegisterToMemoryPass());
|
|
}
|
|
|
|
void LLVMAddVerifierPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createVerifierPass());
|
|
}
|
|
|
|
void LLVMAddCorrelatedValuePropagationPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createCorrelatedValuePropagationPass());
|
|
}
|
|
|
|
void LLVMAddEarlyCSEPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createEarlyCSEPass(false/*=UseMemorySSA*/));
|
|
}
|
|
|
|
void LLVMAddEarlyCSEMemSSAPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createEarlyCSEPass(true/*=UseMemorySSA*/));
|
|
}
|
|
|
|
void LLVMAddGVNHoistLegacyPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createGVNHoistPass());
|
|
}
|
|
|
|
void LLVMAddTypeBasedAliasAnalysisPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createTypeBasedAAWrapperPass());
|
|
}
|
|
|
|
void LLVMAddScopedNoAliasAAPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createScopedNoAliasAAWrapperPass());
|
|
}
|
|
|
|
void LLVMAddBasicAliasAnalysisPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createBasicAAWrapperPass());
|
|
}
|
|
|
|
void LLVMAddLowerConstantIntrinsicsPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createLowerConstantIntrinsicsPass());
|
|
}
|
|
|
|
void LLVMAddLowerExpectIntrinsicPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createLowerExpectIntrinsicPass());
|
|
}
|
|
|
|
void LLVMAddUnifyFunctionExitNodesPass(LLVMPassManagerRef PM) {
|
|
unwrap(PM)->add(createUnifyFunctionExitNodesPass());
|
|
}
|