diff --git a/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp b/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp index fbf5551b812a..d22b3f409585 100644 --- a/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp +++ b/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp @@ -56,7 +56,6 @@ #include "llvm/IR/DataLayout.h" #include "llvm/IR/Dominators.h" #include "llvm/IR/Function.h" -#include "llvm/IR/IRBuilder.h" #include "llvm/IR/InstIterator.h" #include "llvm/IR/InstrTypes.h" #include "llvm/IR/Instruction.h" @@ -79,7 +78,6 @@ #include "llvm/Support/raw_ostream.h" #include "llvm/Transforms/Scalar.h" #include "llvm/Transforms/Utils/AssumeBundleBuilder.h" -#include "llvm/Transforms/Utils/BuildLibCalls.h" #include "llvm/Transforms/Utils/Local.h" #include #include @@ -507,12 +505,7 @@ memoryIsNotModifiedBetween(Instruction *FirstI, Instruction *SecondI, BasicBlock::iterator SecondBBI(SecondI); BasicBlock *FirstBB = FirstI->getParent(); BasicBlock *SecondBB = SecondI->getParent(); - MemoryLocation MemLoc; - if (auto *MemSet = dyn_cast(SecondI)) - MemLoc = MemoryLocation::getForDest(MemSet); - else - MemLoc = MemoryLocation::get(SecondI); - + MemoryLocation MemLoc = MemoryLocation::get(SecondI); auto *MemLocPtr = const_cast(MemLoc.Ptr); // Start checking the SecondBB. @@ -826,17 +819,14 @@ bool isNoopIntrinsic(Instruction *I) { } // Check if we can ignore \p D for DSE. -bool canSkipDef(MemoryDef *D, bool DefVisibleToCaller, - const TargetLibraryInfo &TLI) { +bool canSkipDef(MemoryDef *D, bool DefVisibleToCaller) { Instruction *DI = D->getMemoryInst(); // Calls that only access inaccessible memory cannot read or write any memory // locations we consider for elimination. if (auto *CB = dyn_cast(DI)) - if (CB->onlyAccessesInaccessibleMemory()) { - if (isAllocLikeFn(DI, &TLI)) - return false; + if (CB->onlyAccessesInaccessibleMemory()) return true; - } + // We can eliminate stores to locations not visible to the caller across // throwing instructions. if (DI->mayThrow() && !DefVisibleToCaller) @@ -851,7 +841,7 @@ bool canSkipDef(MemoryDef *D, bool DefVisibleToCaller, return true; // Skip intrinsics that do not really read or modify memory. - if (isNoopIntrinsic(DI)) + if (isNoopIntrinsic(D->getMemoryInst())) return true; return false; @@ -1399,7 +1389,7 @@ struct DSEState { MemoryDef *CurrentDef = cast(Current); Instruction *CurrentI = CurrentDef->getMemoryInst(); - if (canSkipDef(CurrentDef, !isInvisibleToCallerBeforeRet(DefUO), TLI)) + if (canSkipDef(CurrentDef, !isInvisibleToCallerBeforeRet(DefUO))) continue; // Before we try to remove anything, check for any extra throwing @@ -1826,53 +1816,13 @@ struct DSEState { if (StoredConstant && StoredConstant->isNullValue()) { auto *DefUOInst = dyn_cast(DefUO); - if (DefUOInst) { - if (isCallocLikeFn(DefUOInst, &TLI)) { - auto *UnderlyingDef = - cast(MSSA.getMemoryAccess(DefUOInst)); - // If UnderlyingDef is the clobbering access of Def, no instructions - // between them can modify the memory location. - auto *ClobberDef = - MSSA.getSkipSelfWalker()->getClobberingMemoryAccess(Def); - return UnderlyingDef == ClobberDef; - } - - if (MemSet) { - auto *Malloc = const_cast(dyn_cast(DefUOInst)); - if (!Malloc) - return false; - auto *InnerCallee = Malloc->getCalledFunction(); - if (!InnerCallee) - return false; - LibFunc Func; - if (!TLI.getLibFunc(*InnerCallee, Func) || !TLI.has(Func) || - Func != LibFunc_malloc) - return false; - if (Malloc->getOperand(0) == MemSet->getLength()) { - if (DT.dominates(Malloc, MemSet) && - memoryIsNotModifiedBetween(Malloc, MemSet, BatchAA, DL, &DT)) { - IRBuilder<> IRB(Malloc); - const auto &DL = Malloc->getModule()->getDataLayout(); - AttributeList EmptyList; - if (auto *Calloc = emitCalloc( - ConstantInt::get(IRB.getIntPtrTy(DL), 1), - Malloc->getArgOperand(0), EmptyList, IRB, TLI)) { - MemorySSAUpdater Updater(&MSSA); - auto *LastDef = cast( - Updater.getMemorySSA()->getMemoryAccess(Malloc)); - auto *NewAccess = Updater.createMemoryAccessAfter( - cast(Calloc), LastDef, LastDef); - auto *NewAccessMD = cast(NewAccess); - Updater.insertDef(NewAccessMD, /*RenameUses=*/true); - Updater.removeMemoryAccess(Malloc); - Malloc->replaceAllUsesWith(Calloc); - Malloc->eraseFromParent(); - return true; - } - return false; - } - } - } + if (DefUOInst && isCallocLikeFn(DefUOInst, &TLI)) { + auto *UnderlyingDef = cast(MSSA.getMemoryAccess(DefUOInst)); + // If UnderlyingDef is the clobbering access of Def, no instructions + // between them can modify the memory location. + auto *ClobberDef = + MSSA.getSkipSelfWalker()->getClobberingMemoryAccess(Def); + return UnderlyingDef == ClobberDef; } } diff --git a/llvm/test/Transforms/DeadStoreElimination/noop-stores.ll b/llvm/test/Transforms/DeadStoreElimination/noop-stores.ll index 083ecc2b4a1a..184653982a6a 100644 --- a/llvm/test/Transforms/DeadStoreElimination/noop-stores.ll +++ b/llvm/test/Transforms/DeadStoreElimination/noop-stores.ll @@ -1,6 +1,6 @@ ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt < %s -basic-aa -dse -S | FileCheck %s -; RUN: opt < %s -aa-pipeline=basic-aa -passes='dse,verify' -S | FileCheck %s +; RUN: opt < %s -aa-pipeline=basic-aa -passes=dse -S | FileCheck %s target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128" declare i8* @calloc(i64, i64) @@ -309,128 +309,6 @@ entry: ret void } -declare noalias i8* @malloc(i64) -declare noalias i8* @_Znwm(i64) -declare void @clobber_memory(float*) - -; based on pr25892_lite -define i8* @zero_memset_after_malloc(i64 %size) { -; CHECK-LABEL: @zero_memset_after_malloc( -; CHECK-NEXT: [[CALL:%.*]] = call i8* @calloc(i64 1, i64 [[SIZE:%.*]]) -; CHECK-NEXT: ret i8* [[CALL]] -; - %call = call i8* @malloc(i64 %size) inaccessiblememonly - call void @llvm.memset.p0i8.i64(i8* %call, i8 0, i64 %size, i1 false) - ret i8* %call -} - -; based on pr25892_lite -define i8* @zero_memset_after_malloc_with_intermediate_clobbering(i64 %size) { -; CHECK-LABEL: @zero_memset_after_malloc_with_intermediate_clobbering( -; CHECK-NEXT: [[CALL:%.*]] = call i8* @malloc(i64 [[SIZE:%.*]]) -; CHECK-NEXT: [[BC:%.*]] = bitcast i8* [[CALL]] to float* -; CHECK-NEXT: call void @clobber_memory(float* [[BC]]) -; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* [[CALL]], i8 0, i64 [[SIZE]], i1 false) -; CHECK-NEXT: ret i8* [[CALL]] -; - %call = call i8* @malloc(i64 %size) inaccessiblememonly - %bc = bitcast i8* %call to float* - call void @clobber_memory(float* %bc) - call void @llvm.memset.p0i8.i64(i8* %call, i8 0, i64 %size, i1 false) - ret i8* %call -} - -; based on pr25892_lite -define i8* @zero_memset_after_malloc_with_different_sizes(i64 %size) { -; CHECK-LABEL: @zero_memset_after_malloc_with_different_sizes( -; CHECK-NEXT: [[CALL:%.*]] = call i8* @malloc(i64 [[SIZE:%.*]]) -; CHECK-NEXT: [[SIZE2:%.*]] = add nsw i64 [[SIZE]], -1 -; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* [[CALL]], i8 0, i64 [[SIZE2]], i1 false) -; CHECK-NEXT: ret i8* [[CALL]] -; - %call = call i8* @malloc(i64 %size) inaccessiblememonly - %size2 = add nsw i64 %size, -1 - call void @llvm.memset.p0i8.i64(i8* %call, i8 0, i64 %size2, i1 false) - ret i8* %call -} - -; based on pr25892_lite -define i8* @zero_memset_after_new(i64 %size) { -; CHECK-LABEL: @zero_memset_after_new( -; CHECK-NEXT: [[CALL:%.*]] = call i8* @_Znwm(i64 [[SIZE:%.*]]) -; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* [[CALL]], i8 0, i64 [[SIZE]], i1 false) -; CHECK-NEXT: ret i8* [[CALL]] -; - %call = call i8* @_Znwm(i64 %size) - call void @llvm.memset.p0i8.i64(i8* %call, i8 0, i64 %size, i1 false) - ret i8* %call -} - -; This should not create a calloc and should not crash the compiler. -define i8* @notmalloc_memset(i64 %size, i8*(i64)* %notmalloc) { -; CHECK-LABEL: @notmalloc_memset( -; CHECK-NEXT: [[CALL1:%.*]] = call i8* [[NOTMALLOC:%.*]](i64 [[SIZE:%.*]]) -; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* [[CALL1]], i8 0, i64 [[SIZE]], i1 false) -; CHECK-NEXT: ret i8* [[CALL1]] -; - %call1 = call i8* %notmalloc(i64 %size) - call void @llvm.memset.p0i8.i64(i8* %call1, i8 0, i64 %size, i1 false) - ret i8* %call1 -} - -define float* @pr25892(i64 %size) { -; CHECK-LABEL: @pr25892( -; CHECK: entry: -; CHECK-NEXT: [[CALL:%.*]] = call i8* @calloc(i64 1, i64 [[SIZE:%.*]]) -; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8* [[CALL]], null -; CHECK-NEXT: br i1 [[CMP]], label [[CLEANUP:%.*]], label [[IF_END:%.*]] -; CHECK: if.end: -; CHECK-NEXT: [[BC:%.*]] = bitcast i8* [[CALL]] to float* -; CHECK-NEXT: br label [[CLEANUP]] -; CHECK: cleanup: -; CHECK-NEXT: [[RETVAL_0:%.*]] = phi float* [ [[BC]], [[IF_END]] ], [ null, [[ENTRY:%.*]] ] -; CHECK-NEXT: ret float* [[RETVAL_0]] -; -entry: - %call = call i8* @malloc(i64 %size) inaccessiblememonly - %cmp = icmp eq i8* %call, null - br i1 %cmp, label %cleanup, label %if.end -if.end: - %bc = bitcast i8* %call to float* - call void @llvm.memset.p0i8.i64(i8* %call, i8 0, i64 %size, i1 false) - br label %cleanup -cleanup: - %retval.0 = phi float* [ %bc, %if.end ], [ null, %entry ] - ret float* %retval.0 -} - -; CHECK-LABEL: @pr25892_with_extra_store( -; CHECK: entry: -; CHECK-NEXT: [[CALL:%.*]] = call i8* @calloc(i64 1, i64 [[SIZE:%.*]]) -; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8* [[CALL]], null -; CHECK-NEXT: br i1 [[CMP]], label [[CLEANUP:%.*]], label [[IF_END:%.*]] -; CHECK: if.end: -; CHECK-NEXT: [[BC:%.*]] = bitcast i8* [[CALL]] to float* -; CHECK-NEXT: br label [[CLEANUP]] -; CHECK: cleanup: -; CHECK-NEXT: [[RETVAL_0:%.*]] = phi float* [ [[BC]], [[IF_END]] ], [ null, [[ENTRY:%.*]] ] -; CHECK-NEXT: ret float* [[RETVAL_0]] -; -define float* @pr25892_with_extra_store(i64 %size) { -entry: - %call = call i8* @malloc(i64 %size) inaccessiblememonly - %cmp = icmp eq i8* %call, null - br i1 %cmp, label %cleanup, label %if.end -if.end: - %bc = bitcast i8* %call to float* - call void @llvm.memset.p0i8.i64(i8* %call, i8 0, i64 %size, i1 false) - store i8 0, i8* %call, align 1 - br label %cleanup -cleanup: - %retval.0 = phi float* [ %bc, %if.end ], [ null, %entry ] - ret float* %retval.0 -} - ; PR50143 define i8* @store_zero_after_calloc_inaccessiblememonly() { ; CHECK-LABEL: @store_zero_after_calloc_inaccessiblememonly(