[llvm] r277393 - [PM] Port SpeculativeExecution to the new PM
Sean Silva via llvm-commits
llvm-commits at lists.llvm.org
Mon Aug 1 16:42:48 PDT 2016
Thanks for doing this one. The name changing thing made this one a bit
strange to port.
This is also the last non-loop-related pass needed for the per-TU O3
pipeline!
(ignoring CGSCC stuff which you can grab from http://reviews.llvm.org/D21921
)
Only LoopLoadElimination and LoopUnswitch are left I think. (LoopUnswitch
requires an API (addLoop) which the new PM LoopPassManager doesn't have).
-- Sean Silva
On Mon, Aug 1, 2016 at 2:48 PM, Michael Kuperstein via llvm-commits <
llvm-commits at lists.llvm.org> wrote:
> Author: mkuper
> Date: Mon Aug 1 16:48:33 2016
> New Revision: 277393
>
> URL: http://llvm.org/viewvc/llvm-project?rev=277393&view=rev
> Log:
> [PM] Port SpeculativeExecution to the new PM
>
> Differential Revision: https://reviews.llvm.org/D23033
>
> Added:
> llvm/trunk/include/llvm/Transforms/Scalar/SpeculativeExecution.h
> Modified:
> llvm/trunk/include/llvm/InitializePasses.h
> llvm/trunk/lib/Passes/PassBuilder.cpp
> llvm/trunk/lib/Passes/PassRegistry.def
> llvm/trunk/lib/Transforms/Scalar/Scalar.cpp
> llvm/trunk/lib/Transforms/Scalar/SpeculativeExecution.cpp
> llvm/trunk/test/Transforms/SpeculativeExecution/spec.ll
>
> Modified: llvm/trunk/include/llvm/InitializePasses.h
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/InitializePasses.h?rev=277393&r1=277392&r2=277393&view=diff
>
> ==============================================================================
> --- llvm/trunk/include/llvm/InitializePasses.h (original)
> +++ llvm/trunk/include/llvm/InitializePasses.h Mon Aug 1 16:48:33 2016
> @@ -313,7 +313,7 @@ void initializeSingleLoopExtractorPass(P
> void initializeSinkingLegacyPassPass(PassRegistry&);
> void initializeSjLjEHPreparePass(PassRegistry&);
> void initializeSlotIndexesPass(PassRegistry&);
> -void initializeSpeculativeExecutionPass(PassRegistry&);
> +void initializeSpeculativeExecutionLegacyPassPass(PassRegistry&);
> void initializeSpillPlacementPass(PassRegistry&);
> void initializeStackColoringPass(PassRegistry&);
> void initializeStackMapLivenessPass(PassRegistry&);
>
> Added: llvm/trunk/include/llvm/Transforms/Scalar/SpeculativeExecution.h
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Scalar/SpeculativeExecution.h?rev=277393&view=auto
>
> ==============================================================================
> --- llvm/trunk/include/llvm/Transforms/Scalar/SpeculativeExecution.h
> (added)
> +++ llvm/trunk/include/llvm/Transforms/Scalar/SpeculativeExecution.h Mon
> Aug 1 16:48:33 2016
> @@ -0,0 +1,92 @@
> +//===- SpeculativeExecution.h -----------------------------------*- C++
> -*-===//
> +//
> +// The LLVM Compiler Infrastructure
> +//
> +// This file is distributed under the University of Illinois Open Source
> +// License. See LICENSE.TXT for details.
> +//
>
> +//===----------------------------------------------------------------------===//
> +//
> +// This pass hoists instructions to enable speculative execution on
> +// targets where branches are expensive. This is aimed at GPUs. It
> +// currently works on simple if-then and if-then-else
> +// patterns.
> +//
> +// Removing branches is not the only motivation for this
> +// pass. E.g. consider this code and assume that there is no
> +// addressing mode for multiplying by sizeof(*a):
> +//
> +// if (b > 0)
> +// c = a[i + 1]
> +// if (d > 0)
> +// e = a[i + 2]
> +//
> +// turns into
> +//
> +// p = &a[i + 1];
> +// if (b > 0)
> +// c = *p;
> +// q = &a[i + 2];
> +// if (d > 0)
> +// e = *q;
> +//
> +// which could later be optimized to
> +//
> +// r = &a[i];
> +// if (b > 0)
> +// c = r[1];
> +// if (d > 0)
> +// e = r[2];
> +//
> +// Later passes sink back much of the speculated code that did not enable
> +// further optimization.
> +//
> +// This pass is more aggressive than the function SpeculativeyExecuteBB in
> +// SimplifyCFG. SimplifyCFG will not speculate if no selects are
> introduced and
> +// it will speculate at most one instruction. It also will not speculate
> if
> +// there is a value defined in the if-block that is only used in the
> then-block.
> +// These restrictions make sense since the speculation in SimplifyCFG
> seems
> +// aimed at introducing cheap selects, while this pass is intended to do
> more
> +// aggressive speculation while counting on later passes to either
> capitalize on
> +// that or clean it up.
> +//
> +// If the pass was created by calling
> +// createSpeculativeExecutionIfHasBranchDivergencePass or the
> +// -spec-exec-only-if-divergent-target option is present, this pass only
> has an
> +// effect on targets where TargetTransformInfo::hasBranchDivergence() is
> true;
> +// on other targets, it is a nop.
> +//
> +// This lets you include this pass unconditionally in the IR pass
> pipeline, but
> +// only enable it for relevant targets.
> +//
>
> +//===----------------------------------------------------------------------===//
> +#ifndef LLVM_TRANSFORMS_SCALAR_SPECULATIVEEXECUTION_H
> +#define LLVM_TRANSFORMS_SCALAR_SPECULATIVEEXECUTION_H
> +
> +#include "llvm/Analysis/TargetTransformInfo.h"
> +#include "llvm/IR/PassManager.h"
> +
> +namespace llvm {
> +class SpeculativeExecutionPass
> + : public PassInfoMixin<SpeculativeExecutionPass> {
> +public:
> + SpeculativeExecutionPass(bool OnlyIfDivergentTarget = false);
> +
> + PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
> +
> + // Glue for old PM
> + bool runImpl(Function &F, TargetTransformInfo *TTI);
> +
> +private:
> + bool runOnBasicBlock(BasicBlock &B);
> + bool considerHoistingFromTo(BasicBlock &FromBlock, BasicBlock &ToBlock);
> +
> + // If true, this pass is a nop unless the target architecture has branch
> + // divergence.
> + const bool OnlyIfDivergentTarget = false;
> +
> + TargetTransformInfo *TTI = nullptr;
> +};
> +}
> +
> +#endif //LLVM_TRANSFORMS_SCALAR_SPECULATIVEEXECUTION_H
>
> Modified: llvm/trunk/lib/Passes/PassBuilder.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Passes/PassBuilder.cpp?rev=277393&r1=277392&r2=277393&view=diff
>
> ==============================================================================
> --- llvm/trunk/lib/Passes/PassBuilder.cpp (original)
> +++ llvm/trunk/lib/Passes/PassBuilder.cpp Mon Aug 1 16:48:33 2016
> @@ -112,6 +112,7 @@
> #include "llvm/Transforms/Scalar/SROA.h"
> #include "llvm/Transforms/Scalar/SimplifyCFG.h"
> #include "llvm/Transforms/Scalar/Sink.h"
> +#include "llvm/Transforms/Scalar/SpeculativeExecution.h"
> #include "llvm/Transforms/Scalar/TailRecursionElimination.h"
> #include "llvm/Transforms/Utils/AddDiscriminators.h"
> #include "llvm/Transforms/Utils/BreakCriticalEdges.h"
>
> Modified: llvm/trunk/lib/Passes/PassRegistry.def
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Passes/PassRegistry.def?rev=277393&r1=277392&r2=277393&view=diff
>
> ==============================================================================
> --- llvm/trunk/lib/Passes/PassRegistry.def (original)
> +++ llvm/trunk/lib/Passes/PassRegistry.def Mon Aug 1 16:48:33 2016
> @@ -175,6 +175,7 @@ FUNCTION_PASS("sccp", SCCPPass())
> FUNCTION_PASS("simplify-cfg", SimplifyCFGPass())
> FUNCTION_PASS("sink", SinkingPass())
> FUNCTION_PASS("slp-vectorizer", SLPVectorizerPass())
> +FUNCTION_PASS("speculative-execution", SpeculativeExecutionPass())
> FUNCTION_PASS("sroa", SROA())
> FUNCTION_PASS("tailcallelim", TailCallElimPass())
> FUNCTION_PASS("unreachableblockelim", UnreachableBlockElimPass())
>
> Modified: llvm/trunk/lib/Transforms/Scalar/Scalar.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/Scalar.cpp?rev=277393&r1=277392&r2=277393&view=diff
>
> ==============================================================================
> --- llvm/trunk/lib/Transforms/Scalar/Scalar.cpp (original)
> +++ llvm/trunk/lib/Transforms/Scalar/Scalar.cpp Mon Aug 1 16:48:33 2016
> @@ -80,7 +80,7 @@ void llvm::initializeScalarOpts(PassRegi
> initializeSinkingLegacyPassPass(Registry);
> initializeTailCallElimPass(Registry);
> initializeSeparateConstOffsetFromGEPPass(Registry);
> - initializeSpeculativeExecutionPass(Registry);
> + initializeSpeculativeExecutionLegacyPassPass(Registry);
> initializeStraightLineStrengthReducePass(Registry);
> initializeLoadCombinePass(Registry);
> initializePlaceBackedgeSafepointsImplPass(Registry);
>
> Modified: llvm/trunk/lib/Transforms/Scalar/SpeculativeExecution.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/SpeculativeExecution.cpp?rev=277393&r1=277392&r2=277393&view=diff
>
> ==============================================================================
> --- llvm/trunk/lib/Transforms/Scalar/SpeculativeExecution.cpp (original)
> +++ llvm/trunk/lib/Transforms/Scalar/SpeculativeExecution.cpp Mon Aug 1
> 16:48:33 2016
> @@ -61,9 +61,9 @@
> //
>
> //===----------------------------------------------------------------------===//
>
> +#include "llvm/Transforms/Scalar/SpeculativeExecution.h"
> #include "llvm/ADT/SmallSet.h"
> #include "llvm/Analysis/GlobalsModRef.h"
> -#include "llvm/Analysis/TargetTransformInfo.h"
> #include "llvm/Analysis/ValueTracking.h"
> #include "llvm/IR/Instructions.h"
> #include "llvm/IR/Module.h"
> @@ -101,58 +101,62 @@ static cl::opt<bool> SpecExecOnlyIfDiver
>
> namespace {
>
> -class SpeculativeExecution : public FunctionPass {
> - public:
> - static char ID;
> - explicit SpeculativeExecution(bool OnlyIfDivergentTarget = false)
> - : FunctionPass(ID),
> - OnlyIfDivergentTarget(OnlyIfDivergentTarget ||
> - SpecExecOnlyIfDivergentTarget) {}
> -
> - void getAnalysisUsage(AnalysisUsage &AU) const override;
> - bool runOnFunction(Function &F) override;
> -
> - const char *getPassName() const override {
> - if (OnlyIfDivergentTarget)
> - return "Speculatively execute instructions if target has divergent
> "
> - "branches";
> - return "Speculatively execute instructions";
> - }
> -
> - private:
> - bool runOnBasicBlock(BasicBlock &B);
> - bool considerHoistingFromTo(BasicBlock &FromBlock, BasicBlock &ToBlock);
> +class SpeculativeExecutionLegacyPass : public FunctionPass {
> +public:
> + static char ID;
> + explicit SpeculativeExecutionLegacyPass(bool OnlyIfDivergentTarget =
> false)
> + : FunctionPass(ID), OnlyIfDivergentTarget(OnlyIfDivergentTarget ||
> +
> SpecExecOnlyIfDivergentTarget),
> + Impl(OnlyIfDivergentTarget) {}
> +
> + void getAnalysisUsage(AnalysisUsage &AU) const override;
> + bool runOnFunction(Function &F) override;
> +
> + const char *getPassName() const override {
> + if (OnlyIfDivergentTarget)
> + return "Speculatively execute instructions if target has divergent "
> + "branches";
> + return "Speculatively execute instructions";
> + }
>
> - // If true, this pass is a nop unless the target architecture has branch
> - // divergence.
> +private:
> + // Variable preserved purely for correct name printing.
> const bool OnlyIfDivergentTarget;
> - const TargetTransformInfo *TTI = nullptr;
> +
> + SpeculativeExecutionPass Impl;
> };
> } // namespace
>
> -char SpeculativeExecution::ID = 0;
> -INITIALIZE_PASS_BEGIN(SpeculativeExecution, "speculative-execution",
> +char SpeculativeExecutionLegacyPass::ID = 0;
> +INITIALIZE_PASS_BEGIN(SpeculativeExecutionLegacyPass,
> "speculative-execution",
> "Speculatively execute instructions", false, false)
> INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
> -INITIALIZE_PASS_END(SpeculativeExecution, "speculative-execution",
> +INITIALIZE_PASS_END(SpeculativeExecutionLegacyPass,
> "speculative-execution",
> "Speculatively execute instructions", false, false)
>
> -void SpeculativeExecution::getAnalysisUsage(AnalysisUsage &AU) const {
> +void SpeculativeExecutionLegacyPass::getAnalysisUsage(AnalysisUsage &AU)
> const {
> AU.addRequired<TargetTransformInfoWrapperPass>();
> AU.addPreserved<GlobalsAAWrapperPass>();
> }
>
> -bool SpeculativeExecution::runOnFunction(Function &F) {
> +bool SpeculativeExecutionLegacyPass::runOnFunction(Function &F) {
> if (skipFunction(F))
> return false;
>
> - TTI = &getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F);
> + auto *TTI = &getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F);
> + return Impl.runImpl(F, TTI);
> +}
> +
> +namespace llvm {
> +
> +bool SpeculativeExecutionPass::runImpl(Function &F, TargetTransformInfo
> *TTI) {
> if (OnlyIfDivergentTarget && !TTI->hasBranchDivergence()) {
> DEBUG(dbgs() << "Not running SpeculativeExecution because "
> "TTI->hasBranchDivergence() is false.\n");
> return false;
> }
>
> + this->TTI = TTI;
> bool Changed = false;
> for (auto& B : F) {
> Changed |= runOnBasicBlock(B);
> @@ -160,7 +164,7 @@ bool SpeculativeExecution::runOnFunction
> return Changed;
> }
>
> -bool SpeculativeExecution::runOnBasicBlock(BasicBlock &B) {
> +bool SpeculativeExecutionPass::runOnBasicBlock(BasicBlock &B) {
> BranchInst *BI = dyn_cast<BranchInst>(B.getTerminator());
> if (BI == nullptr)
> return false;
> @@ -227,8 +231,8 @@ static unsigned ComputeSpeculationCost(c
> }
> }
>
> -bool SpeculativeExecution::considerHoistingFromTo(BasicBlock &FromBlock,
> - BasicBlock &ToBlock) {
> +bool SpeculativeExecutionPass::considerHoistingFromTo(
> + BasicBlock &FromBlock, BasicBlock &ToBlock) {
> SmallSet<const Instruction *, 8> NotHoisted;
> const auto AllPrecedingUsesFromBlockHoisted = [&NotHoisted](User *U) {
> for (Value* V : U->operand_values()) {
> @@ -270,14 +274,28 @@ bool SpeculativeExecution::considerHoist
> return true;
> }
>
> -namespace llvm {
> -
> FunctionPass *createSpeculativeExecutionPass() {
> - return new SpeculativeExecution();
> + return new SpeculativeExecutionLegacyPass();
> }
>
> FunctionPass *createSpeculativeExecutionIfHasBranchDivergencePass() {
> - return new SpeculativeExecution(/* OnlyIfDivergentTarget = */ true);
> + return new SpeculativeExecutionLegacyPass(/* OnlyIfDivergentTarget = */
> true);
> }
>
> +SpeculativeExecutionPass::SpeculativeExecutionPass(bool
> OnlyIfDivergentTarget)
> + : OnlyIfDivergentTarget(OnlyIfDivergentTarget ||
> + SpecExecOnlyIfDivergentTarget) {}
> +
> +PreservedAnalyses SpeculativeExecutionPass::run(Function &F,
> + FunctionAnalysisManager
> &AM) {
> + auto *TTI = &AM.getResult<TargetIRAnalysis>(F);
> +
> + bool Changed = runImpl(F, TTI);
> +
> + if (!Changed)
> + return PreservedAnalyses::all();
> + PreservedAnalyses PA;
> + PA.preserve<GlobalsAA>();
> + return PA;
> +}
> } // namespace llvm
>
> Modified: llvm/trunk/test/Transforms/SpeculativeExecution/spec.ll
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SpeculativeExecution/spec.ll?rev=277393&r1=277392&r2=277393&view=diff
>
> ==============================================================================
> --- llvm/trunk/test/Transforms/SpeculativeExecution/spec.ll (original)
> +++ llvm/trunk/test/Transforms/SpeculativeExecution/spec.ll Mon Aug 1
> 16:48:33 2016
> @@ -1,6 +1,9 @@
> ; RUN: opt < %s -S -speculative-execution \
> ; RUN: -spec-exec-max-speculation-cost 4 -spec-exec-max-not-hoisted 3 \
> ; RUN: | FileCheck %s
> +; RUN: opt < %s -S -passes='speculative-execution' \
> +; RUN: -spec-exec-max-speculation-cost 4 -spec-exec-max-not-hoisted 3 \
> +; RUN: | FileCheck %s
>
> target datalayout = "e-i64:64-v16:16-v32:32-n16:32:64"
>
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20160801/188d7689/attachment.html>
More information about the llvm-commits
mailing list