Index: llvm/include/llvm/Transforms/Utils/MoveAutoInit.h =================================================================== --- /dev/null +++ llvm/include/llvm/Transforms/Utils/MoveAutoInit.h @@ -0,0 +1,29 @@ +//===- MoveAutoInit.h - Move insts marked as auto-init Pass --*- C++ -*-======// +// +// 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 pass moves instructions marked as auto-init closer to their use if +// profitable, generally because it moves them under a guard, potentially +// skipping the overhead of the auto-init under some execution paths. +// +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_TRANSFORMS_UTILS_MOVEAUTOINIT_H +#define LLVM_TRANSFORMS_UTILS_MOVEAUTOINIT_H + +#include "llvm/IR/PassManager.h" + +namespace llvm { + +class MoveAutoInitPass : public PassInfoMixin { +public: + PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM); +}; +} // end namespace llvm + +#endif // LLVM_TRANSFORMS_UTILS_MOVEAUTOINIT_H Index: llvm/lib/Passes/PassBuilder.cpp =================================================================== --- llvm/lib/Passes/PassBuilder.cpp +++ llvm/lib/Passes/PassBuilder.cpp @@ -247,6 +247,7 @@ #include "llvm/Transforms/Utils/LowerSwitch.h" #include "llvm/Transforms/Utils/Mem2Reg.h" #include "llvm/Transforms/Utils/MetaRenamer.h" +#include "llvm/Transforms/Utils/MoveAutoInit.h" #include "llvm/Transforms/Utils/NameAnonGlobals.h" #include "llvm/Transforms/Utils/PredicateInfo.h" #include "llvm/Transforms/Utils/RelLookupTableConverter.h" Index: llvm/lib/Passes/PassBuilderPipelines.cpp =================================================================== --- llvm/lib/Passes/PassBuilderPipelines.cpp +++ llvm/lib/Passes/PassBuilderPipelines.cpp @@ -125,6 +125,7 @@ #include "llvm/Transforms/Utils/InjectTLIMappings.h" #include "llvm/Transforms/Utils/LibCallsShrinkWrap.h" #include "llvm/Transforms/Utils/Mem2Reg.h" +#include "llvm/Transforms/Utils/MoveAutoInit.h" #include "llvm/Transforms/Utils/NameAnonGlobals.h" #include "llvm/Transforms/Utils/RelLookupTableConverter.h" #include "llvm/Transforms/Utils/SimplifyCFGOptions.h" @@ -656,6 +657,8 @@ FPM.addPass(MemCpyOptPass()); FPM.addPass(DSEPass()); + FPM.addPass(MoveAutoInitPass()); + FPM.addPass(createFunctionToLoopPassAdaptor( LICMPass(PTO.LicmMssaOptCap, PTO.LicmMssaNoAccForPromotionCap, /*AllowSpeculation=*/true), @@ -1796,6 +1799,7 @@ // Nuke dead stores. MainFPM.addPass(DSEPass()); + MainFPM.addPass(MoveAutoInitPass()); MainFPM.addPass(MergedLoadStoreMotionPass()); LoopPassManager LPM; Index: llvm/lib/Passes/PassRegistry.def =================================================================== --- llvm/lib/Passes/PassRegistry.def +++ llvm/lib/Passes/PassRegistry.def @@ -333,6 +333,7 @@ FUNCTION_PASS("memcpyopt", MemCpyOptPass()) FUNCTION_PASS("mergeicmps", MergeICmpsPass()) FUNCTION_PASS("mergereturn", UnifyFunctionExitNodesPass()) +FUNCTION_PASS("move-auto-init", MoveAutoInitPass()) FUNCTION_PASS("nary-reassociate", NaryReassociatePass()) FUNCTION_PASS("newgvn", NewGVNPass()) FUNCTION_PASS("jump-threading", JumpThreadingPass()) Index: llvm/lib/Transforms/Utils/CMakeLists.txt =================================================================== --- llvm/lib/Transforms/Utils/CMakeLists.txt +++ llvm/lib/Transforms/Utils/CMakeLists.txt @@ -58,6 +58,7 @@ MetaRenamer.cpp MisExpect.cpp ModuleUtils.cpp + MoveAutoInit.cpp NameAnonGlobals.cpp PredicateInfo.cpp PromoteMemoryToRegister.cpp Index: llvm/lib/Transforms/Utils/MoveAutoInit.cpp =================================================================== --- /dev/null +++ llvm/lib/Transforms/Utils/MoveAutoInit.cpp @@ -0,0 +1,224 @@ +//===-- MoveAutoInit.cpp - move auto-init inst closer to their use site----===// +// +// 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 pass moves instruction maked as auto-init closer to the basic block that +// use it, eventually removing it from some control path of the function. +// +//===----------------------------------------------------------------------===// + +#include "llvm/Transforms/Utils/MoveAutoInit.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/Statistic.h" +#include "llvm/ADT/StringSet.h" +#include "llvm/Analysis/MemorySSA.h" +#include "llvm/Analysis/MemorySSAUpdater.h" +#include "llvm/IR/DebugInfo.h" +#include "llvm/IR/Dominators.h" +#include "llvm/IR/IRBuilder.h" +#include "llvm/IR/Instructions.h" +#include "llvm/IR/IntrinsicInst.h" +#include "llvm/Support/CommandLine.h" +#include "llvm/Transforms/Utils.h" +#include "llvm/Transforms/Utils/LoopUtils.h" + +using namespace llvm; + +#define DEBUG_TYPE "move-auto-init" + +STATISTIC(NumMoved, "Number of instructions moved"); + +static cl::opt MoveAutoInitThreshold( + "move-auto-init-threshold", + cl::Hidden, cl::init(128), + cl::desc("Maximum instructions to analyze per moved initialization")); + + +static bool hasAutoInitMetadata(const Instruction &I) { + return I.hasMetadata(LLVMContext::MD_annotation) && + any_of(I.getMetadata(LLVMContext::MD_annotation)->operands(), + [](const MDOperand &Op) { + return cast(Op.get())->getString() == "auto-init"; + }); +} + +constexpr unsigned MaxVisitedInstructionCount = 128; + +/// Finds a BasicBlock in the CFG where instruction `I` can be moved to while +/// not changing the Memory SSA ordering and being guarded by at least one +/// condition. +static BasicBlock *usersDominator(Instruction *I, DominatorTree &DT, + MemorySSA &MSSA) { + BasicBlock *CurrentDominator = nullptr; + MemoryLocation ML; + if (auto *MI = dyn_cast(I)) + ML = MemoryLocation::getForDest(MI); + else if (auto *SI = dyn_cast(I)) + ML = MemoryLocation::get(SI); + else + assert(false && "memory location set"); + + MemoryUseOrDef &IMA = *MSSA.getMemoryAccess(I); + BatchAAResults AA(MSSA.getAA()); + + SmallPtrSet Visited; + + auto AsMemoryAccess = [](User *U) { return cast(U); }; + SmallVector WorkList(map_range(IMA.users(), AsMemoryAccess)); + + while (!WorkList.empty()) { + MemoryAccess *MA = WorkList.pop_back_val(); + if (!Visited.insert(MA).second) + continue; + + if (Visited.size() > MoveAutoInitThreshold) + return nullptr; + + bool FoundClobberingUser = false; + if (auto *M = dyn_cast(MA)) { + Instruction *MI = M->getMemoryInst(); + + // If this memory instruction may not clobber `I`, we can skip it. + // LifetimeEnd is a valid user, but we do not want it in the user + // dominator. + if (AA.getModRefInfo(MI, ML) != ModRefInfo::NoModRef && + !MI->isLifetimeStartOrEnd() && MI != I) { + FoundClobberingUser = true; + CurrentDominator = CurrentDominator + ? DT.findNearestCommonDominator(CurrentDominator, + MI->getParent()) + : MI->getParent(); + } + } + if (!FoundClobberingUser) { + auto UsersAsMemoryAccesses = map_range(MA->users(), AsMemoryAccess); + append_range(WorkList, UsersAsMemoryAccesses); + } + } + return CurrentDominator; +} + +static bool runMoveAutoInit(Function &F, DominatorTree &DT, MemorySSA &MSSA) { + BasicBlock &EntryBB = F.getEntryBlock(); + SmallVector> JobList; + + // + // Compute movable instructions. + // + for (Instruction &I : EntryBB) { + if (!hasAutoInitMetadata(I)) + continue; + + assert(!I.isVolatile() && "auto init instructions cannot be volatile."); + + BasicBlock *UsersDominator = usersDominator(&I, DT, MSSA); + if (!UsersDominator) + continue; + + if (UsersDominator == &EntryBB) + continue; + + // Traverse the CFG to detect cycles `UsersDominator` would be part of. + SmallPtrSet TransitiveSuccessors; + SmallVector WorkList(successors(UsersDominator)); + bool HasCycle = false; + while (!WorkList.empty()) { + BasicBlock *CurrBB = WorkList.pop_back_val(); + if (CurrBB == UsersDominator) + // No early exit because we want to compute the full set of transitive + // successors. + HasCycle = true; + for (BasicBlock *Successor : successors(CurrBB)) { + if (!TransitiveSuccessors.insert(Successor).second) + continue; + WorkList.push_back(Successor); + } + } + + // Don't insert if that could create multiple execution of I, + // but we can insert it in the non back-edge predecessors, if it exists. + if (HasCycle) { + BasicBlock *UsersDominatorHead = UsersDominator; + while (BasicBlock *UniquePredecessor = + UsersDominatorHead->getUniquePredecessor()) + UsersDominatorHead = UniquePredecessor; + + if (UsersDominatorHead == &EntryBB) + continue; + + BasicBlock *DominatingPredecessor = nullptr; + for (BasicBlock *Pred : predecessors(UsersDominatorHead)) { + // If one of the predecessor of the dominator also transitively is a + // successor, moving to the dominator would do the inverse of loop + // hoisting, and we don't want that. + if (TransitiveSuccessors.count(Pred)) + continue; + + DominatingPredecessor = + DominatingPredecessor + ? DT.findNearestCommonDominator(DominatingPredecessor, Pred) + : Pred; + } + + if (!DominatingPredecessor || DominatingPredecessor == &EntryBB) + continue; + + UsersDominator = DominatingPredecessor; + } + + // We finally found a place where I can be moved while not introducing extra + // execution, and guarded by at least one condition. + Instruction *UsersDominatorInsertionPt = + &*UsersDominator->getFirstInsertionPt(); + + // CatchSwitchInst blocks can only have one instruction, so they are not + // good candidates for insertion. + while (isa(UsersDominatorInsertionPt)) { + for (BasicBlock *Pred : predecessors(UsersDominator)) + UsersDominator = DT.findNearestCommonDominator(UsersDominator, Pred); + UsersDominatorInsertionPt = &*UsersDominator->getFirstInsertionPt(); + } + + JobList.emplace_back(&I, UsersDominatorInsertionPt); + } + + // + // Perform the actual substitution. + // + if (JobList.empty()) + return false; + + MemorySSAUpdater MSSAU(&MSSA); + + for (auto &Job : JobList) { + Job.first->moveBefore(Job.second); + MSSAU.moveToPlace(MSSA.getMemoryAccess(Job.first), Job.second->getParent(), + MemorySSA::InsertionPlace::Beginning); + } + + if (VerifyMemorySSA) + MSSA.verifyMemorySSA(); + + NumMoved += JobList.size(); + + return true; +} + +PreservedAnalyses MoveAutoInitPass::run(Function &F, + FunctionAnalysisManager &AM) { + + auto &DT = AM.getResult(F); + auto &MSSA = AM.getResult(F).getMSSA(); + if (!runMoveAutoInit(F, DT, MSSA)) + return PreservedAnalyses::all(); + + PreservedAnalyses PA; + PA.preserve(); + PA.preserve(); + PA.preserveSet(); + return PA; +} Index: llvm/test/Other/new-pm-defaults.ll =================================================================== --- llvm/test/Other/new-pm-defaults.ll +++ llvm/test/Other/new-pm-defaults.ll @@ -206,6 +206,7 @@ ; CHECK-O-NEXT: Running analysis: PostDominatorTreeAnalysis ; CHECK-O23SZ-NEXT: Running pass: MemCpyOptPass ; CHECK-O23SZ-NEXT: Running pass: DSEPass +; CHECK-O23SZ-NEXT: Running pass: MoveAutoInitPass on foo ; CHECK-O23SZ-NEXT: Running pass: LoopSimplifyPass ; CHECK-O23SZ-NEXT: Running pass: LCSSAPass ; CHECK-O23SZ-NEXT: Running pass: LICMPass Index: llvm/test/Other/new-pm-lto-defaults.ll =================================================================== --- llvm/test/Other/new-pm-lto-defaults.ll +++ llvm/test/Other/new-pm-lto-defaults.ll @@ -108,6 +108,7 @@ ; CHECK-O23SZ-NEXT: Running pass: MemCpyOptPass on foo ; CHECK-O23SZ-NEXT: Running pass: DSEPass on foo ; CHECK-O23SZ-NEXT: Running analysis: PostDominatorTreeAnalysis on foo +; CHECK-O23SZ-NEXT: Running pass: MoveAutoInitPass on foo ; CHECK-O23SZ-NEXT: Running pass: MergedLoadStoreMotionPass on foo ; CHECK-O23SZ-NEXT: Running pass: LoopSimplifyPass on foo ; CHECK-O23SZ-NEXT: Running pass: LCSSAPass on foo Index: llvm/test/Other/new-pm-thinlto-postlink-defaults.ll =================================================================== --- llvm/test/Other/new-pm-thinlto-postlink-defaults.ll +++ llvm/test/Other/new-pm-thinlto-postlink-defaults.ll @@ -149,6 +149,7 @@ ; CHECK-O-NEXT: Running analysis: PostDominatorTreeAnalysis ; CHECK-O23SZ-NEXT: Running pass: MemCpyOptPass ; CHECK-O23SZ-NEXT: Running pass: DSEPass +; CHECK-O23SZ-NEXT: Running pass: MoveAutoInitPass on foo ; CHECK-O23SZ-NEXT: Running pass: LoopSimplifyPass ; CHECK-O23SZ-NEXT: Running pass: LCSSAPass ; CHECK-O23SZ-NEXT: Running pass: LICMPass on loop Index: llvm/test/Other/new-pm-thinlto-postlink-pgo-defaults.ll =================================================================== --- llvm/test/Other/new-pm-thinlto-postlink-pgo-defaults.ll +++ llvm/test/Other/new-pm-thinlto-postlink-pgo-defaults.ll @@ -136,6 +136,7 @@ ; CHECK-O-NEXT: Running pass: ADCEPass ; CHECK-O23SZ-NEXT: Running pass: MemCpyOptPass ; CHECK-O23SZ-NEXT: Running pass: DSEPass +; CHECK-O23SZ-NEXT: Running pass: MoveAutoInitPass on foo ; CHECK-O23SZ-NEXT: Running pass: LoopSimplifyPass ; CHECK-O23SZ-NEXT: Running pass: LCSSAPass ; CHECK-O23SZ-NEXT: Running pass: LICMPass Index: llvm/test/Other/new-pm-thinlto-postlink-samplepgo-defaults.ll =================================================================== --- llvm/test/Other/new-pm-thinlto-postlink-samplepgo-defaults.ll +++ llvm/test/Other/new-pm-thinlto-postlink-samplepgo-defaults.ll @@ -143,6 +143,7 @@ ; CHECK-O-NEXT: Running pass: ADCEPass ; CHECK-O23SZ-NEXT: Running pass: MemCpyOptPass ; CHECK-O23SZ-NEXT: Running pass: DSEPass +; CHECK-O23SZ-NEXT: Running pass: MoveAutoInitPass ; CHECK-O23SZ-NEXT: Running pass: LoopSimplifyPass ; CHECK-O23SZ-NEXT: Running pass: LCSSAPass ; CHECK-O23SZ-NEXT: Running pass: LICMPass Index: llvm/test/Other/new-pm-thinlto-prelink-defaults.ll =================================================================== --- llvm/test/Other/new-pm-thinlto-prelink-defaults.ll +++ llvm/test/Other/new-pm-thinlto-prelink-defaults.ll @@ -147,6 +147,7 @@ ; CHECK-O-NEXT: Running analysis: PostDominatorTreeAnalysis ; CHECK-O23SZ-NEXT: Running pass: MemCpyOptPass ; CHECK-O23SZ-NEXT: Running pass: DSEPass +; CHECK-O23SZ-NEXT: Running pass: MoveAutoInitPass ; CHECK-O23SZ-NEXT: Running pass: LoopSimplifyPass ; CHECK-O23SZ-NEXT: Running pass: LCSSAPass ; CHECK-O23SZ-NEXT: Running pass: LICMPass on loop Index: llvm/test/Other/new-pm-thinlto-prelink-pgo-defaults.ll =================================================================== --- llvm/test/Other/new-pm-thinlto-prelink-pgo-defaults.ll +++ llvm/test/Other/new-pm-thinlto-prelink-pgo-defaults.ll @@ -172,6 +172,7 @@ ; CHECK-O-NEXT: Running pass: ADCEPass ; CHECK-O23SZ-NEXT: Running pass: MemCpyOptPass ; CHECK-O23SZ-NEXT: Running pass: DSEPass +; CHECK-O23SZ-NEXT: Running pass: MoveAutoInitPass on foo ; CHECK-O23SZ-NEXT: Running pass: LoopSimplifyPass ; CHECK-O23SZ-NEXT: Running pass: LCSSAPass ; CHECK-O23SZ-NEXT: Running pass: LICMPass Index: llvm/test/Other/new-pm-thinlto-prelink-samplepgo-defaults.ll =================================================================== --- llvm/test/Other/new-pm-thinlto-prelink-samplepgo-defaults.ll +++ llvm/test/Other/new-pm-thinlto-prelink-samplepgo-defaults.ll @@ -137,6 +137,7 @@ ; CHECK-O-NEXT: Running pass: ADCEPass ; CHECK-O23SZ-NEXT: Running pass: MemCpyOptPass ; CHECK-O23SZ-NEXT: Running pass: DSEPass +; CHECK-O23SZ-NEXT: Running pass: MoveAutoInitPass on foo ; CHECK-O23SZ-NEXT: Running pass: LoopSimplifyPass ; CHECK-O23SZ-NEXT: Running pass: LCSSAPass ; CHECK-O23SZ-NEXT: Running pass: LICMPass Index: llvm/test/Transforms/MoveAutoInit/branch.ll =================================================================== --- /dev/null +++ llvm/test/Transforms/MoveAutoInit/branch.ll @@ -0,0 +1,41 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt < %s -S -passes='move-auto-init' -verify-memoryssa | FileCheck %s + +@__const.foo.buffer = private unnamed_addr constant [8 x i32] [i32 -1431655766, i32 -1431655766, i32 -1431655766, i32 -1431655766, i32 -1431655766, i32 -1431655766, i32 -1431655766, i32 -1431655766], align 16 + +define void @foo(i32 %x) { +; CHECK-LABEL: @foo( +; CHECK-NEXT: entry: +; CHECK-NEXT: [[BUFFER:%.*]] = alloca [8 x i32], align 16 +; CHECK-NEXT: [[TOBOOL:%.*]] = icmp ne i32 [[X:%.*]], 0 +; CHECK-NEXT: br i1 [[TOBOOL]], label [[IF_THEN:%.*]], label [[IF_END:%.*]] +; CHECK: if.then: +; CHECK-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr align 16 [[BUFFER]], ptr align 16 @__const.foo.buffer, i64 32, i1 false), !annotation !0 +; CHECK-NEXT: call void @dump(ptr [[BUFFER]]) +; CHECK-NEXT: br label [[IF_END]] +; CHECK: if.end: +; CHECK-NEXT: ret void +; + +entry: + %buffer = alloca [8 x i32], align 16 + call void @llvm.memcpy.p0.p0.i64(ptr align 16 %buffer, ptr align 16 @__const.foo.buffer, i64 32, i1 false), !annotation !0 + %tobool = icmp ne i32 %x, 0 + br i1 %tobool, label %if.then, label %if.end + +if.then: ; preds = %entry + call void @dump(ptr %buffer) + br label %if.end + +if.end: ; preds = %if.then, %entry + ret void +} + + + +declare void @llvm.memcpy.p0.p0.i64(ptr noalias nocapture writeonly, ptr noalias nocapture readonly, i64, i1 immarg) + +declare void @dump(ptr) + +!0 = !{!"auto-init"} + Index: llvm/test/Transforms/MoveAutoInit/clobber.ll =================================================================== --- /dev/null +++ llvm/test/Transforms/MoveAutoInit/clobber.ll @@ -0,0 +1,100 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; Checks that move-auto-init can move instruction passed unclobbering memory +; instructions. +; RUN: opt < %s -S -passes='move-auto-init' -verify-memoryssa | FileCheck %s + +target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128" + +define i32 @foo(i32 noundef %0, i32 noundef %1, i32 noundef %2) #0 { +; CHECK-LABEL: @foo( +; CHECK-NEXT: [[TMP4:%.*]] = alloca [100 x i8], align 16 +; CHECK-NEXT: [[TMP5:%.*]] = alloca [2 x i8], align 1 +; CHECK-NEXT: [[TMP6:%.*]] = getelementptr inbounds [100 x i8], ptr [[TMP4]], i64 0, i64 0 +; CHECK-NEXT: call void @llvm.lifetime.start.p0(i64 100, ptr nonnull [[TMP6]]) #[[ATTR3:[0-9]+]] +; CHECK-NEXT: [[TMP7:%.*]] = getelementptr inbounds [2 x i8], ptr [[TMP5]], i64 0, i64 0 +; CHECK-NEXT: call void @llvm.lifetime.start.p0(i64 2, ptr nonnull [[TMP7]]) #[[ATTR3]] +; CHECK-NEXT: [[TMP8:%.*]] = getelementptr inbounds [2 x i8], ptr [[TMP5]], i64 0, i64 1 +; CHECK-NEXT: [[TMP9:%.*]] = icmp eq i32 [[TMP1:%.*]], 0 +; CHECK-NEXT: br i1 [[TMP9]], label [[TMP15:%.*]], label [[TMP10:%.*]] +; CHECK: 10: +; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr noundef nonnull align 16 dereferenceable(100) [[TMP6]], i8 -86, i64 100, i1 false), !annotation !0 +; CHECK-NEXT: [[TMP11:%.*]] = sext i32 [[TMP0:%.*]] to i64 +; CHECK-NEXT: [[TMP12:%.*]] = getelementptr inbounds [100 x i8], ptr [[TMP4]], i64 0, i64 [[TMP11]] +; CHECK-NEXT: store i8 12, ptr [[TMP12]], align 1 +; CHECK-NEXT: [[TMP13:%.*]] = load i8, ptr [[TMP6]], align 16 +; CHECK-NEXT: [[TMP14:%.*]] = sext i8 [[TMP13]] to i32 +; CHECK-NEXT: br label [[TMP22:%.*]] +; CHECK: 15: +; CHECK-NEXT: [[TMP16:%.*]] = icmp eq i32 [[TMP2:%.*]], 0 +; CHECK-NEXT: br i1 [[TMP16]], label [[TMP22]], label [[TMP17:%.*]] +; CHECK: 17: +; CHECK-NEXT: store i8 -86, ptr [[TMP7]], align 1, !annotation !0 +; CHECK-NEXT: store i8 -86, ptr [[TMP8]], align 1, !annotation !0 +; CHECK-NEXT: [[TMP18:%.*]] = sext i32 [[TMP0]] to i64 +; CHECK-NEXT: [[TMP19:%.*]] = getelementptr inbounds [2 x i8], ptr [[TMP5]], i64 0, i64 [[TMP18]] +; CHECK-NEXT: store i8 12, ptr [[TMP19]], align 1 +; CHECK-NEXT: [[TMP20:%.*]] = load i8, ptr [[TMP7]], align 1 +; CHECK-NEXT: [[TMP21:%.*]] = sext i8 [[TMP20]] to i32 +; CHECK-NEXT: br label [[TMP22]] +; CHECK: 22: +; CHECK-NEXT: [[TMP23:%.*]] = phi i32 [ [[TMP14]], [[TMP10]] ], [ [[TMP21]], [[TMP17]] ], [ 0, [[TMP15]] ] +; CHECK-NEXT: call void @llvm.lifetime.end.p0(i64 2, ptr nonnull [[TMP7]]) #[[ATTR3]] +; CHECK-NEXT: call void @llvm.lifetime.end.p0(i64 100, ptr nonnull [[TMP6]]) #[[ATTR3]] +; CHECK-NEXT: ret i32 [[TMP23]] +; + + %4 = alloca [100 x i8], align 16 + %5 = alloca [2 x i8], align 1 + %6 = getelementptr inbounds [100 x i8], [100 x i8]* %4, i64 0, i64 0 + call void @llvm.lifetime.start.p0i8(i64 100, i8* nonnull %6) #3 + ; This memset must move. + call void @llvm.memset.p0i8.i64(i8* noundef nonnull align 16 dereferenceable(100) %6, i8 -86, i64 100, i1 false), !annotation !0 + %7 = getelementptr inbounds [2 x i8], [2 x i8]* %5, i64 0, i64 0 + call void @llvm.lifetime.start.p0i8(i64 2, i8* nonnull %7) #3 + ; This store must move. + store i8 -86, i8* %7, align 1, !annotation !0 + %8 = getelementptr inbounds [2 x i8], [2 x i8]* %5, i64 0, i64 1 + ; This store must move. + store i8 -86, i8* %8, align 1, !annotation !0 + %9 = icmp eq i32 %1, 0 + br i1 %9, label %15, label %10 + +10: + %11 = sext i32 %0 to i64 + %12 = getelementptr inbounds [100 x i8], [100 x i8]* %4, i64 0, i64 %11 + store i8 12, i8* %12, align 1 + %13 = load i8, i8* %6, align 16 + %14 = sext i8 %13 to i32 + br label %22 + +15: + %16 = icmp eq i32 %2, 0 + br i1 %16, label %22, label %17 + +17: + %18 = sext i32 %0 to i64 + %19 = getelementptr inbounds [2 x i8], [2 x i8]* %5, i64 0, i64 %18 + store i8 12, i8* %19, align 1 + %20 = load i8, i8* %7, align 1 + %21 = sext i8 %20 to i32 + br label %22 + +22: + %23 = phi i32 [ %14, %10 ], [ %21, %17 ], [ 0, %15 ] + call void @llvm.lifetime.end.p0i8(i64 2, i8* nonnull %7) #3 + call void @llvm.lifetime.end.p0i8(i64 100, i8* nonnull %6) #3 + ret i32 %23 +} + +declare void @llvm.lifetime.start.p0i8(i64 immarg, i8* nocapture) #1 + +declare void @llvm.memset.p0i8.i64(i8* nocapture writeonly, i8, i64, i1 immarg) #2 + +declare void @llvm.lifetime.end.p0i8(i64 immarg, i8* nocapture) #1 + +attributes #0 = { mustprogress nofree nosync nounwind readnone uwtable willreturn } +attributes #1 = { argmemonly mustprogress nofree nosync nounwind willreturn } +attributes #2 = { argmemonly mustprogress nofree nounwind willreturn writeonly } +attributes #3 = { nounwind } + +!0 = !{!"auto-init"} Index: llvm/test/Transforms/MoveAutoInit/fence.ll =================================================================== --- /dev/null +++ llvm/test/Transforms/MoveAutoInit/fence.ll @@ -0,0 +1,70 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt < %s -S -passes='move-auto-init' -verify-memoryssa | FileCheck %s + +target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128" + +; In that case, the store to %val happens before the fence and cannot go past +; it. +define void @foo(i32 %x) { +; CHECK-LABEL: @foo( +; CHECK-NEXT: entry: +; CHECK-NEXT: [[VAL:%.*]] = alloca i32, align 4 +; CHECK-NEXT: store i32 -1431655766, ptr [[VAL]], align 4, !annotation !0 +; CHECK-NEXT: [[TOBOOL:%.*]] = icmp ne i32 [[X:%.*]], 0 +; CHECK-NEXT: fence acquire +; CHECK-NEXT: br i1 [[TOBOOL]], label [[IF_THEN:%.*]], label [[IF_END:%.*]] +; CHECK: if.then: +; CHECK-NEXT: call void @dump(ptr [[VAL]]) +; CHECK-NEXT: br label [[IF_END]] +; CHECK: if.end: +; CHECK-NEXT: ret void +; +entry: + %val = alloca i32, align 4 + store i32 -1431655766, ptr %val, align 4, !annotation !0 + %tobool = icmp ne i32 %x, 0 + fence acquire + br i1 %tobool, label %if.then, label %if.end + +if.then: ; preds = %entry + call void @dump(ptr %val) + br label %if.end + +if.end: ; preds = %if.then, %entry + ret void +} + +; In that case, the store to %val happens after the fence and it is moved within +; the true branch as expected. +define void @bar(i32 %x) { +; CHECK-LABEL: @bar( +; CHECK-NEXT: entry: +; CHECK-NEXT: [[VAL:%.*]] = alloca i32, align 4 +; CHECK-NEXT: [[TOBOOL:%.*]] = icmp ne i32 [[X:%.*]], 0 +; CHECK-NEXT: fence acquire +; CHECK-NEXT: br i1 [[TOBOOL]], label [[IF_THEN:%.*]], label [[IF_END:%.*]] +; CHECK: if.then: +; CHECK-NEXT: store i32 -1431655766, ptr [[VAL]], align 4, !annotation !0 +; CHECK-NEXT: call void @dump(ptr [[VAL]]) +; CHECK-NEXT: br label [[IF_END]] +; CHECK: if.end: +; CHECK-NEXT: ret void +; +entry: + %val = alloca i32, align 4 + %tobool = icmp ne i32 %x, 0 + fence acquire + store i32 -1431655766, ptr %val, align 4, !annotation !0 + br i1 %tobool, label %if.then, label %if.end + +if.then: ; preds = %entry + call void @dump(ptr %val) + br label %if.end + +if.end: ; preds = %if.then, %entry + ret void +} + +declare void @dump(ptr) + +!0 = !{!"auto-init"} Index: llvm/test/Transforms/MoveAutoInit/loop.ll =================================================================== --- /dev/null +++ llvm/test/Transforms/MoveAutoInit/loop.ll @@ -0,0 +1,102 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt < %s -S -passes='move-auto-init' -verify-memoryssa | FileCheck %s + +target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128" + +define void @foo(i32 %x) { +; CHECK-LABEL: @foo( +; CHECK-NEXT: entry: +; CHECK-NEXT: [[BUFFER:%.*]] = alloca [80 x i32], align 16 +; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr align 16 [[BUFFER]], i8 -86, i64 320, i1 false), !annotation !0 +; CHECK-NEXT: br label [[DO_BODY:%.*]] +; CHECK: do.body: +; CHECK-NEXT: [[X_ADDR_0:%.*]] = phi i32 [ [[X:%.*]], [[ENTRY:%.*]] ], [ [[DEC:%.*]], [[DO_COND:%.*]] ] +; CHECK-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [80 x i32], ptr [[BUFFER]], i64 0, i64 0 +; CHECK-NEXT: call void @dump(ptr [[ARRAYIDX]]) +; CHECK-NEXT: br label [[DO_COND]] +; CHECK: do.cond: +; CHECK-NEXT: [[DEC]] = add nsw i32 [[X_ADDR_0]], -1 +; CHECK-NEXT: [[TOBOOL:%.*]] = icmp ne i32 [[X_ADDR_0]], 0 +; CHECK-NEXT: br i1 [[TOBOOL]], label [[DO_BODY]], label [[DO_END:%.*]] +; CHECK: do.end: +; CHECK-NEXT: ret void +; + +entry: + %buffer = alloca [80 x i32], align 16 + call void @llvm.memset.p0.i64(ptr align 16 %buffer, i8 -86, i64 320, i1 false), !annotation !0 + br label %do.body + +do.body: ; preds = %do.cond, %entry + %x.addr.0 = phi i32 [ %x, %entry ], [ %dec, %do.cond ] + %arrayidx = getelementptr inbounds [80 x i32], ptr %buffer, i64 0, i64 0 + call void @dump(ptr %arrayidx) + br label %do.cond + +do.cond: ; preds = %do.body + %dec = add nsw i32 %x.addr.0, -1 + %tobool = icmp ne i32 %x.addr.0, 0 + br i1 %tobool, label %do.body, label %do.end + +do.end: ; preds = %do.cond + ret void +} + +declare void @llvm.memset.p0.i64(ptr nocapture writeonly, i8, i64, i1 immarg) + +declare void @dump(ptr ) + +define void @bar(i32 %x, i32 %y) { +; CHECK-LABEL: @bar( +; CHECK-NEXT: entry: +; CHECK-NEXT: [[BUFFER:%.*]] = alloca [80 x i32], align 16 +; CHECK-NEXT: [[TOBOOL:%.*]] = icmp ne i32 [[Y:%.*]], 0 +; CHECK-NEXT: br i1 [[TOBOOL]], label [[IF_THEN:%.*]], label [[IF_END:%.*]] +; CHECK: if.then: +; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr align 16 [[BUFFER]], i8 -86, i64 320, i1 false), !annotation !0 +; CHECK-NEXT: [[ADD:%.*]] = add nsw i32 [[X:%.*]], [[Y]] +; CHECK-NEXT: br label [[DO_BODY:%.*]] +; CHECK: do.body: +; CHECK-NEXT: [[X_ADDR_0:%.*]] = phi i32 [ [[ADD]], [[IF_THEN]] ], [ [[DEC:%.*]], [[DO_COND:%.*]] ] +; CHECK-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [80 x i32], ptr [[BUFFER]], i64 0, i64 0 +; CHECK-NEXT: call void @dump(ptr [[ARRAYIDX]]) +; CHECK-NEXT: br label [[DO_COND]] +; CHECK: do.cond: +; CHECK-NEXT: [[DEC]] = add nsw i32 [[X_ADDR_0]], -1 +; CHECK-NEXT: [[TOBOOL1:%.*]] = icmp ne i32 [[X_ADDR_0]], 0 +; CHECK-NEXT: br i1 [[TOBOOL1]], label [[DO_BODY]], label [[DO_END:%.*]] +; CHECK: do.end: +; CHECK-NEXT: br label [[IF_END]] +; CHECK: if.end: +; CHECK-NEXT: ret void +; + +entry: + %buffer = alloca [80 x i32], align 16 + call void @llvm.memset.p0.i64(ptr align 16 %buffer, i8 -86, i64 320, i1 false), !annotation !0 + %tobool = icmp ne i32 %y, 0 + br i1 %tobool, label %if.then, label %if.end + +if.then: ; preds = %entry + %add = add nsw i32 %x, %y + br label %do.body + +do.body: ; preds = %do.cond, %if.then + %x.addr.0 = phi i32 [ %add, %if.then ], [ %dec, %do.cond ] + %arrayidx = getelementptr inbounds [80 x i32], ptr %buffer, i64 0, i64 0 + call void @dump(ptr %arrayidx) + br label %do.cond + +do.cond: ; preds = %do.body + %dec = add nsw i32 %x.addr.0, -1 + %tobool1 = icmp ne i32 %x.addr.0, 0 + br i1 %tobool1, label %do.body, label %do.end + +do.end: ; preds = %do.cond + br label %if.end + +if.end: ; preds = %do.end, %entry + ret void +} + +!0 = !{!"auto-init"} Index: llvm/test/Transforms/MoveAutoInit/scalar.ll =================================================================== --- /dev/null +++ llvm/test/Transforms/MoveAutoInit/scalar.ll @@ -0,0 +1,36 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt < %s -S -passes='move-auto-init' -verify-memoryssa | FileCheck %s + +target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128" + +define void @foo(i32 %x) { +; CHECK-LABEL: @foo( +; CHECK-NEXT: entry: +; CHECK-NEXT: [[VAL:%.*]] = alloca i32, align 4 +; CHECK-NEXT: [[TOBOOL:%.*]] = icmp ne i32 [[X:%.*]], 0 +; CHECK-NEXT: br i1 [[TOBOOL]], label [[IF_THEN:%.*]], label [[IF_END:%.*]] +; CHECK: if.then: +; CHECK-NEXT: store i32 -1431655766, ptr [[VAL]], align 4, !annotation !0 +; CHECK-NEXT: call void @dump(ptr [[VAL]]) +; CHECK-NEXT: br label [[IF_END]] +; CHECK: if.end: +; CHECK-NEXT: ret void +; + +entry: + %val = alloca i32, align 4 + store i32 -1431655766, ptr %val, align 4, !annotation !0 + %tobool = icmp ne i32 %x, 0 + br i1 %tobool, label %if.then, label %if.end + +if.then: ; preds = %entry + call void @dump(ptr %val) + br label %if.end + +if.end: ; preds = %if.then, %entry + ret void +} + +declare void @dump(ptr) + +!0 = !{!"auto-init"}