From 9c1b82599dac63816cbed80270aaec85a6fa153b Mon Sep 17 00:00:00 2001 From: Sameer Sahasrabuddhe Date: Sun, 18 Dec 2022 10:51:20 +0530 Subject: [PATCH] [AAPointerInfo] handle multiple offsets in PHI Previously reverted in 8b446ea2ba39e406bcf940ea35d6efb4bb9afe95 Reapplying because this commit is NOT DEPENDENT on the reverted commit fc21f2d7bae2e0be630470cc7ca9323ed5859892, which broke the ASAN buildbot. See https://reviews.llvm.org/rGfc21f2d7bae2e0be630470cc7ca9323ed5859892 for more information. The arguments to a PHI may represent a recurrence by eventually using the output of the PHI itself. This is now handled by checking for cycles in the control flow. If a PHI is not in a recurrence, it is now able to report multiple offsets instead of conservatively reporting unknown. Reviewed By: jdoerfert Differential Revision: https://reviews.llvm.org/D138991 --- llvm/include/llvm/Analysis/CycleAnalysis.h | 44 +++--- llvm/include/llvm/Transforms/IPO/Attributor.h | 33 +++- llvm/lib/Target/AMDGPU/AMDGPUAttributor.cpp | 17 ++- llvm/lib/Transforms/IPO/AttributorAttributes.cpp | 49 ++++-- llvm/test/CodeGen/AMDGPU/implicitarg-attributes.ll | 30 ++++ llvm/test/CodeGen/AMDGPU/llc-pipeline.ll | 10 ++ .../Attributor/multiple-offsets-pointer-info.ll | 169 +++++++++++++++++++++ 7 files changed, 315 insertions(+), 37 deletions(-) diff --git a/llvm/include/llvm/Analysis/CycleAnalysis.h b/llvm/include/llvm/Analysis/CycleAnalysis.h index 539d29e..30bf685 100644 --- a/llvm/include/llvm/Analysis/CycleAnalysis.h +++ b/llvm/include/llvm/Analysis/CycleAnalysis.h @@ -27,6 +27,27 @@ extern template class GenericCycle; using CycleInfo = GenericCycleInfo; using Cycle = CycleInfo::CycleT; +/// Legacy analysis pass which computes a \ref CycleInfo. +class CycleInfoWrapperPass : public FunctionPass { + Function *F = nullptr; + CycleInfo CI; + +public: + static char ID; + + CycleInfoWrapperPass(); + + CycleInfo &getResult() { return CI; } + const CycleInfo &getResult() const { return CI; } + + bool runOnFunction(Function &F) override; + void getAnalysisUsage(AnalysisUsage &AU) const override; + void releaseMemory() override; + void print(raw_ostream &OS, const Module *M = nullptr) const override; + + // TODO: verify analysis? +}; + /// Analysis pass which computes a \ref CycleInfo. class CycleAnalysis : public AnalysisInfoMixin { friend AnalysisInfoMixin; @@ -36,6 +57,8 @@ public: /// Provide the result typedef for this analysis pass. using Result = CycleInfo; + using LegacyWrapper = CycleInfoWrapperPass; + /// Run the analysis pass over a function and produce a dominator tree. CycleInfo run(Function &F, FunctionAnalysisManager &); @@ -52,27 +75,6 @@ public: PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM); }; -/// Legacy analysis pass which computes a \ref CycleInfo. -class CycleInfoWrapperPass : public FunctionPass { - Function *F = nullptr; - CycleInfo CI; - -public: - static char ID; - - CycleInfoWrapperPass(); - - CycleInfo &getCycleInfo() { return CI; } - const CycleInfo &getCycleInfo() const { return CI; } - - bool runOnFunction(Function &F) override; - void getAnalysisUsage(AnalysisUsage &AU) const override; - void releaseMemory() override; - void print(raw_ostream &OS, const Module *M = nullptr) const override; - - // TODO: verify analysis? -}; - } // end namespace llvm #endif // LLVM_ANALYSIS_CYCLEANALYSIS_H diff --git a/llvm/include/llvm/Transforms/IPO/Attributor.h b/llvm/include/llvm/Transforms/IPO/Attributor.h index d311c39..52cfb40 100644 --- a/llvm/include/llvm/Transforms/IPO/Attributor.h +++ b/llvm/include/llvm/Transforms/IPO/Attributor.h @@ -1050,22 +1050,47 @@ public: iterator end() { return IRPositions.end(); } }; -/// Wrapper for FunctoinAnalysisManager. +/// Wrapper for FunctionAnalysisManager. struct AnalysisGetter { + // The client may be running the old pass manager, in which case, we need to + // map the requested Analysis to its equivalent wrapper in the old pass + // manager. The scheme implemented here does not require every Analysis to be + // updated. Only those new analyses that the client cares about in the old + // pass manager need to expose a LegacyWrapper type, and that wrapper should + // support a getResult() method that matches the new Analysis. + // + // We need SFINAE to check for the LegacyWrapper, but function templates don't + // allow partial specialization, which is needed in this case. So instead, we + // use a constexpr bool to perform the SFINAE, and then use this information + // inside the function template. + template static constexpr bool HasLegacyWrapper = false; + template typename Analysis::Result *getAnalysis(const Function &F) { - if (!FAM || !F.getParent()) - return nullptr; - return &FAM->getResult(const_cast(F)); + if (FAM) + return &FAM->getResult(const_cast(F)); + if constexpr (HasLegacyWrapper) + if (LegacyPass) + return &LegacyPass + ->getAnalysis( + const_cast(F)) + .getResult(); + return nullptr; } AnalysisGetter(FunctionAnalysisManager &FAM) : FAM(&FAM) {} + AnalysisGetter(Pass *P) : LegacyPass(P) {} AnalysisGetter() = default; private: FunctionAnalysisManager *FAM = nullptr; + Pass *LegacyPass = nullptr; }; +template +constexpr bool AnalysisGetter::HasLegacyWrapper< + Analysis, std::void_t> = true; + /// Data structure to hold cached (LLVM-IR) information. /// /// All attributes are given an InformationCache object at creation time to diff --git a/llvm/lib/Target/AMDGPU/AMDGPUAttributor.cpp b/llvm/lib/Target/AMDGPU/AMDGPUAttributor.cpp index b332054..6feceb0 100644 --- a/llvm/lib/Target/AMDGPU/AMDGPUAttributor.cpp +++ b/llvm/lib/Target/AMDGPU/AMDGPUAttributor.cpp @@ -13,6 +13,7 @@ #include "AMDGPU.h" #include "GCNSubtarget.h" #include "Utils/AMDGPUBaseInfo.h" +#include "llvm/Analysis/CycleAnalysis.h" #include "llvm/CodeGen/TargetPassConfig.h" #include "llvm/IR/IntrinsicsAMDGPU.h" #include "llvm/IR/IntrinsicsR600.h" @@ -21,6 +22,10 @@ #define DEBUG_TYPE "amdgpu-attributor" +namespace llvm { +void initializeCycleInfoWrapperPassPass(PassRegistry &); +} + using namespace llvm; #define AMDGPU_ATTRIBUTE(Name, Str) Name##_POS, @@ -747,7 +752,7 @@ public: bool runOnModule(Module &M) override { SetVector Functions; - AnalysisGetter AG; + AnalysisGetter AG(this); for (Function &F : M) { if (!F.isIntrinsic()) Functions.insert(&F); @@ -782,6 +787,10 @@ public: return Change == ChangeStatus::CHANGED; } + void getAnalysisUsage(AnalysisUsage &AU) const override { + AU.addRequired(); + } + StringRef getPassName() const override { return "AMDGPU Attributor"; } TargetMachine *TM; static char ID; @@ -791,4 +800,8 @@ public: char AMDGPUAttributor::ID = 0; Pass *llvm::createAMDGPUAttributorPass() { return new AMDGPUAttributor(); } -INITIALIZE_PASS(AMDGPUAttributor, DEBUG_TYPE, "AMDGPU Attributor", false, false) +INITIALIZE_PASS_BEGIN(AMDGPUAttributor, DEBUG_TYPE, "AMDGPU Attributor", false, + false) +INITIALIZE_PASS_DEPENDENCY(CycleInfoWrapperPass); +INITIALIZE_PASS_END(AMDGPUAttributor, DEBUG_TYPE, "AMDGPU Attributor", false, + false) diff --git a/llvm/lib/Transforms/IPO/AttributorAttributes.cpp b/llvm/lib/Transforms/IPO/AttributorAttributes.cpp index f5c462e..937f257 100644 --- a/llvm/lib/Transforms/IPO/AttributorAttributes.cpp +++ b/llvm/lib/Transforms/IPO/AttributorAttributes.cpp @@ -28,6 +28,7 @@ #include "llvm/Analysis/AssumeBundleQueries.h" #include "llvm/Analysis/AssumptionCache.h" #include "llvm/Analysis/CaptureTracking.h" +#include "llvm/Analysis/CycleAnalysis.h" #include "llvm/Analysis/InstructionSimplify.h" #include "llvm/Analysis/LazyValueInfo.h" #include "llvm/Analysis/MemoryBuiltins.h" @@ -1430,10 +1431,13 @@ ChangeStatus AAPointerInfoFloating::updateImpl(Attributor &A) { return true; }; + const auto *F = getAnchorScope(); + const auto *CI = + F ? A.getInfoCache().getAnalysisResultForFunction(*F) + : nullptr; const auto *TLI = - getAnchorScope() - ? A.getInfoCache().getTargetLibraryInfoForFunction(*getAnchorScope()) - : nullptr; + F ? A.getInfoCache().getTargetLibraryInfoForFunction(*F) : nullptr; + auto UsePred = [&](const Use &U, bool &Follow) -> bool { Value *CurPtr = U.get(); User *Usr = U.getUser(); @@ -1505,14 +1509,39 @@ ChangeStatus AAPointerInfoFloating::updateImpl(Attributor &A) { return true; } - // Check if the PHI operand is not dependent on the PHI itself. + // Check if the PHI operand can be traced back to AssociatedValue. APInt Offset( DL.getIndexSizeInBits(CurPtr->getType()->getPointerAddressSpace()), 0); Value *CurPtrBase = CurPtr->stripAndAccumulateConstantOffsets( DL, Offset, /* AllowNonInbounds */ true); auto It = OffsetInfoMap.find(CurPtrBase); - if (It != OffsetInfoMap.end()) { + if (It == OffsetInfoMap.end()) { + LLVM_DEBUG(dbgs() << "[AAPointerInfo] PHI operand is too complex " + << *CurPtr << " in " << *Usr << "\n"); + UsrOI.setUnknown(); + Follow = true; + return true; + } + + auto mayBeInCycleHeader = [](const CycleInfo *CI, const Instruction *I) { + if (!CI) + return true; + auto *BB = I->getParent(); + auto *C = CI->getCycle(BB); + if (!C) + return false; + return BB == C->getHeader(); + }; + + // Check if the PHI operand is not dependent on the PHI itself. Every + // recurrence is a cyclic net of PHIs in the data flow, and has an + // equivalent Cycle in the control flow. One of those PHIs must be in the + // header of that control flow Cycle. This is independent of the choice of + // Cycles reported by CycleInfo. It is sufficient to check the PHIs in + // every Cycle header; if such a node is marked unknown, this will + // eventually propagate through the whole net of PHIs in the recurrence. + if (mayBeInCycleHeader(CI, cast(Usr))) { auto BaseOI = It->getSecond(); BaseOI.addToAll(Offset.getZExtValue()); if (IsFirstPHIUser || BaseOI == UsrOI) { @@ -1520,16 +1549,16 @@ ChangeStatus AAPointerInfoFloating::updateImpl(Attributor &A) { << " in " << *Usr << "\n"); return HandlePassthroughUser(Usr, PtrOI, Follow); } + LLVM_DEBUG( dbgs() << "[AAPointerInfo] PHI operand pointer offset mismatch " << *CurPtr << " in " << *Usr << "\n"); - } else { - LLVM_DEBUG(dbgs() << "[AAPointerInfo] PHI operand is too complex " - << *CurPtr << " in " << *Usr << "\n"); + UsrOI.setUnknown(); + Follow = true; + return true; } - // TODO: Approximate in case we know the direction of the recurrence. - UsrOI.setUnknown(); + UsrOI.merge(PtrOI); Follow = true; return true; } diff --git a/llvm/test/CodeGen/AMDGPU/implicitarg-attributes.ll b/llvm/test/CodeGen/AMDGPU/implicitarg-attributes.ll index 0fba6ab..f4da140 100644 --- a/llvm/test/CodeGen/AMDGPU/implicitarg-attributes.ll +++ b/llvm/test/CodeGen/AMDGPU/implicitarg-attributes.ll @@ -63,6 +63,36 @@ entry: ret void } +; CHECK-NOT: hidden_hostcall_buffer +; CHECK-NOT: hidden_multigrid_sync_arg +; CHECK-LABEL: .name: kernel_3 + +define amdgpu_kernel void @kernel_3(i32 addrspace(1)* %a, i1 %cond) { +entry: + %tmp7 = tail call i8 addrspace(4)* @llvm.amdgcn.implicitarg.ptr() + br i1 %cond, label %old, label %new + +old: ; preds = %entry + %tmp4 = getelementptr i8, i8 addrspace(4)* %tmp7, i64 12 + br label %join + +new: ; preds = %entry + %tmp12 = getelementptr inbounds i8, i8 addrspace(4)* %tmp7, i64 18 + br label %join + +join: ; preds = %new, %old + %.in.in.in = phi i8 addrspace(4)* [ %tmp12, %new ], [ %tmp4, %old ] + %.in.in = bitcast i8 addrspace(4)* %.in.in.in to i16 addrspace(4)* + + ;;; THIS USE of implicitarg_ptr should not produce hostcall metadata + %.in = load i16, i16 addrspace(4)* %.in.in, align 2 + + %idx.ext = sext i16 %.in to i64 + %add.ptr3 = getelementptr inbounds i32, i32 addrspace(1)* %a, i64 %idx.ext + %tmp16 = atomicrmw add i32 addrspace(1)* %add.ptr3, i32 15 syncscope("agent-one-as") monotonic, align 4 + ret void +} + declare i32 @llvm.amdgcn.workitem.id.x() declare align 4 i8 addrspace(4)* @llvm.amdgcn.implicitarg.ptr() diff --git a/llvm/test/CodeGen/AMDGPU/llc-pipeline.ll b/llvm/test/CodeGen/AMDGPU/llc-pipeline.ll index bd2040a..6710668 100644 --- a/llvm/test/CodeGen/AMDGPU/llc-pipeline.ll +++ b/llvm/test/CodeGen/AMDGPU/llc-pipeline.ll @@ -51,6 +51,8 @@ ; GCN-O0-NEXT: Scalarize Masked Memory Intrinsics ; GCN-O0-NEXT: Expand reduction intrinsics ; GCN-O0-NEXT: AMDGPU Attributor +; GCN-O0-NEXT: FunctionPass Manager +; GCN-O0-NEXT: Cycle Info Analysis ; GCN-O0-NEXT: CallGraph Construction ; GCN-O0-NEXT: Call Graph SCC Pass Manager ; GCN-O0-NEXT: AMDGPU Annotate Kernel Features @@ -225,6 +227,8 @@ ; GCN-O1-NEXT: Natural Loop Information ; GCN-O1-NEXT: TLS Variable Hoist ; GCN-O1-NEXT: AMDGPU Attributor +; GCN-O1-NEXT: FunctionPass Manager +; GCN-O1-NEXT: Cycle Info Analysis ; GCN-O1-NEXT: CallGraph Construction ; GCN-O1-NEXT: Call Graph SCC Pass Manager ; GCN-O1-NEXT: AMDGPU Annotate Kernel Features @@ -509,6 +513,8 @@ ; GCN-O1-OPTS-NEXT: TLS Variable Hoist ; GCN-O1-OPTS-NEXT: Early CSE ; GCN-O1-OPTS-NEXT: AMDGPU Attributor +; GCN-O1-OPTS-NEXT: FunctionPass Manager +; GCN-O1-OPTS-NEXT: Cycle Info Analysis ; GCN-O1-OPTS-NEXT: CallGraph Construction ; GCN-O1-OPTS-NEXT: Call Graph SCC Pass Manager ; GCN-O1-OPTS-NEXT: AMDGPU Annotate Kernel Features @@ -807,6 +813,8 @@ ; GCN-O2-NEXT: TLS Variable Hoist ; GCN-O2-NEXT: Early CSE ; GCN-O2-NEXT: AMDGPU Attributor +; GCN-O2-NEXT: FunctionPass Manager +; GCN-O2-NEXT: Cycle Info Analysis ; GCN-O2-NEXT: CallGraph Construction ; GCN-O2-NEXT: Call Graph SCC Pass Manager ; GCN-O2-NEXT: AMDGPU Annotate Kernel Features @@ -1118,6 +1126,8 @@ ; GCN-O3-NEXT: Optimization Remark Emitter ; GCN-O3-NEXT: Global Value Numbering ; GCN-O3-NEXT: AMDGPU Attributor +; GCN-O3-NEXT: FunctionPass Manager +; GCN-O3-NEXT: Cycle Info Analysis ; GCN-O3-NEXT: CallGraph Construction ; GCN-O3-NEXT: Call Graph SCC Pass Manager ; GCN-O3-NEXT: AMDGPU Annotate Kernel Features diff --git a/llvm/test/Transforms/Attributor/multiple-offsets-pointer-info.ll b/llvm/test/Transforms/Attributor/multiple-offsets-pointer-info.ll index 6669f34..a2915d0 100644 --- a/llvm/test/Transforms/Attributor/multiple-offsets-pointer-info.ll +++ b/llvm/test/Transforms/Attributor/multiple-offsets-pointer-info.ll @@ -291,6 +291,172 @@ entry: ret i8 %i } +; FIXME: The whole function is just "ret i8 21". + +define i8 @phi_gep_simplifiable_1(i1 %cnd1, i1 %cnd2) { +; CHECK: Function Attrs: nofree norecurse nosync nounwind willreturn +; CHECK-LABEL: define {{[^@]+}}@phi_gep_simplifiable_1 +; CHECK-SAME: (i1 [[CND1:%.*]], i1 [[CND2:%.*]]) #[[ATTR2]] { +; CHECK-NEXT: entry: +; CHECK-NEXT: [[BYTES:%.*]] = alloca [1024 x i8], align 16 +; CHECK-NEXT: br i1 [[CND1]], label [[THEN:%.*]], label [[ELSE:%.*]] +; CHECK: then: +; CHECK-NEXT: [[GEP23:%.*]] = getelementptr inbounds [1024 x i8], [1024 x i8]* [[BYTES]], i64 0, i64 23 +; CHECK-NEXT: store i8 21, i8* [[GEP23]], align 4 +; CHECK-NEXT: br label [[JOIN:%.*]] +; CHECK: else: +; CHECK-NEXT: [[GEP31:%.*]] = getelementptr inbounds [1024 x i8], [1024 x i8]* [[BYTES]], i64 0, i64 31 +; CHECK-NEXT: store i8 21, i8* [[GEP31]], align 4 +; CHECK-NEXT: br label [[JOIN]] +; CHECK: join: +; CHECK-NEXT: [[PHI_PTR:%.*]] = phi i8* [ [[GEP23]], [[THEN]] ], [ [[GEP31]], [[ELSE]] ] +; CHECK-NEXT: [[GEP29:%.*]] = getelementptr inbounds [1024 x i8], [1024 x i8]* [[BYTES]], i64 0, i64 29 +; CHECK-NEXT: [[I:%.*]] = load i8, i8* [[PHI_PTR]], align 4 +; CHECK-NEXT: ret i8 [[I]] +; +entry: + %Bytes = alloca [1024 x i8], align 16 + br i1 %cnd1, label %then, label %else + +then: + %gep23 = getelementptr inbounds [1024 x i8], [1024 x i8]* %Bytes, i64 0, i64 23 + store i8 21, i8* %gep23, align 4 + br label %join + +else: + %gep31 = getelementptr inbounds [1024 x i8], [1024 x i8]* %Bytes, i64 0, i64 31 + store i8 21, i8* %gep31, align 4 + br label %join + +join: + %phi.ptr = phi i8* [%gep23, %then], [%gep31, %else] + ;; This store is eliminated + %gep29 = getelementptr inbounds [1024 x i8], [1024 x i8]* %Bytes, i64 0, i64 29 + store i8 42, i8* %gep29, align 4 + %i = load i8, i8* %phi.ptr, align 4 + ret i8 %i +} + +; FIXME: The whole function is just "ret i8 42". + +define i8 @phi_gep_simplifiable_2(i1 %cnd1, i1 %cnd2) { +; CHECK: Function Attrs: nofree norecurse nosync nounwind willreturn memory(write) +; CHECK-LABEL: define {{[^@]+}}@phi_gep_simplifiable_2 +; CHECK-SAME: (i1 [[CND1:%.*]], i1 [[CND2:%.*]]) #[[ATTR1]] { +; CHECK-NEXT: entry: +; CHECK-NEXT: [[BYTES:%.*]] = alloca [1024 x i8], align 16 +; CHECK-NEXT: br i1 [[CND1]], label [[THEN:%.*]], label [[ELSE:%.*]] +; CHECK: then: +; CHECK-NEXT: [[GEP23:%.*]] = getelementptr inbounds [1024 x i8], [1024 x i8]* [[BYTES]], i64 0, i64 23 +; CHECK-NEXT: br label [[JOIN:%.*]] +; CHECK: else: +; CHECK-NEXT: [[GEP31:%.*]] = getelementptr inbounds [1024 x i8], [1024 x i8]* [[BYTES]], i64 0, i64 31 +; CHECK-NEXT: br label [[JOIN]] +; CHECK: join: +; CHECK-NEXT: [[PHI_PTR:%.*]] = phi i8* [ [[GEP23]], [[THEN]] ], [ [[GEP31]], [[ELSE]] ] +; CHECK-NEXT: store i8 21, i8* [[PHI_PTR]], align 4 +; CHECK-NEXT: ret i8 42 +; +entry: + %Bytes = alloca [1024 x i8], align 16 + %gep29 = getelementptr inbounds [1024 x i8], [1024 x i8]* %Bytes, i64 0, i64 29 + ;; This store is propagated to the load. + store i8 42, i8* %gep29, align 4 + br i1 %cnd1, label %then, label %else + +then: + %gep23 = getelementptr inbounds [1024 x i8], [1024 x i8]* %Bytes, i64 0, i64 23 + br label %join + +else: + %gep31 = getelementptr inbounds [1024 x i8], [1024 x i8]* %Bytes, i64 0, i64 31 + br label %join + +join: + %phi.ptr = phi i8* [%gep23, %then], [%gep31, %else] + store i8 21, i8* %phi.ptr, align 4 + ;; Replaced with the constant, and both store/load are eliminated. + %i = load i8, i8* %gep29, align 4 + ret i8 %i +} + +define i8 @phi_gep_not_simplifiable_1(i1 %cnd1, i1 %cnd2) { +; CHECK: Function Attrs: nofree norecurse nosync nounwind willreturn +; CHECK-LABEL: define {{[^@]+}}@phi_gep_not_simplifiable_1 +; CHECK-SAME: (i1 [[CND1:%.*]], i1 [[CND2:%.*]]) #[[ATTR2]] { +; CHECK-NEXT: entry: +; CHECK-NEXT: [[BYTES:%.*]] = alloca [1024 x i8], align 16 +; CHECK-NEXT: [[GEP23:%.*]] = getelementptr inbounds [1024 x i8], [1024 x i8]* [[BYTES]], i64 0, i64 23 +; CHECK-NEXT: br i1 [[CND1]], label [[THEN:%.*]], label [[ELSE:%.*]] +; CHECK: then: +; CHECK-NEXT: br label [[JOIN:%.*]] +; CHECK: else: +; CHECK-NEXT: [[GEP31:%.*]] = getelementptr inbounds [1024 x i8], [1024 x i8]* [[BYTES]], i64 0, i64 31 +; CHECK-NEXT: br label [[JOIN]] +; CHECK: join: +; CHECK-NEXT: [[PHI_PTR:%.*]] = phi i8* [ [[GEP23]], [[THEN]] ], [ [[GEP31]], [[ELSE]] ] +; CHECK-NEXT: store i8 42, i8* [[GEP23]], align 4 +; CHECK-NEXT: [[I:%.*]] = load i8, i8* [[PHI_PTR]], align 4 +; CHECK-NEXT: ret i8 [[I]] +; +entry: + %Bytes = alloca [1024 x i8], align 16 + %gep23 = getelementptr inbounds [1024 x i8], [1024 x i8]* %Bytes, i64 0, i64 23 + br i1 %cnd1, label %then, label %else + +then: + br label %join + +else: + %gep31 = getelementptr inbounds [1024 x i8], [1024 x i8]* %Bytes, i64 0, i64 31 + br label %join + +join: + %phi.ptr = phi i8* [%gep23, %then], [%gep31, %else] + ;; This store cannot be eliminated + store i8 42, i8* %gep23, align 4 + %i = load i8, i8* %phi.ptr, align 4 + ret i8 %i +} + +define i8 @phi_gep_not_simplifiable_2(i1 %cnd1, i1 %cnd2) { +; CHECK: Function Attrs: nofree norecurse nosync nounwind willreturn +; CHECK-LABEL: define {{[^@]+}}@phi_gep_not_simplifiable_2 +; CHECK-SAME: (i1 [[CND1:%.*]], i1 [[CND2:%.*]]) #[[ATTR2]] { +; CHECK-NEXT: entry: +; CHECK-NEXT: [[BYTES:%.*]] = alloca [1024 x i8], align 16 +; CHECK-NEXT: [[GEP23:%.*]] = getelementptr inbounds [1024 x i8], [1024 x i8]* [[BYTES]], i64 0, i64 23 +; CHECK-NEXT: br i1 [[CND1]], label [[THEN:%.*]], label [[ELSE:%.*]] +; CHECK: then: +; CHECK-NEXT: br label [[JOIN:%.*]] +; CHECK: else: +; CHECK-NEXT: [[GEP31:%.*]] = getelementptr inbounds [1024 x i8], [1024 x i8]* [[BYTES]], i64 0, i64 31 +; CHECK-NEXT: br label [[JOIN]] +; CHECK: join: +; CHECK-NEXT: [[PHI_PTR:%.*]] = phi i8* [ [[GEP23]], [[THEN]] ], [ [[GEP31]], [[ELSE]] ] +; CHECK-NEXT: store i8 21, i8* [[PHI_PTR]], align 4 +; CHECK-NEXT: [[I:%.*]] = load i8, i8* [[GEP23]], align 4 +; CHECK-NEXT: ret i8 [[I]] +; +entry: + %Bytes = alloca [1024 x i8], align 16 + %gep23 = getelementptr inbounds [1024 x i8], [1024 x i8]* %Bytes, i64 0, i64 23 + br i1 %cnd1, label %then, label %else + +then: + br label %join + +else: + %gep31 = getelementptr inbounds [1024 x i8], [1024 x i8]* %Bytes, i64 0, i64 31 + br label %join + +join: + %phi.ptr = phi i8* [%gep23, %then], [%gep31, %else] + store i8 21, i8* %phi.ptr, align 4 + %i = load i8, i8* %gep23, align 4 + ret i8 %i +} + ; FIXME: This should be simplifiable. See comment inside. define i8 @phi_offsets_fixme(i1 %cnd1, i1 %cnd2) { @@ -340,3 +506,6 @@ join: ; CHECK: attributes #[[ATTR1]] = { nofree norecurse nosync nounwind willreturn memory(write) } ; CHECK: attributes #[[ATTR2]] = { nofree norecurse nosync nounwind willreturn } ;. +;; NOTE: These prefixes are unused and the list is autogenerated. Do not add tests below this line: +; CGSCC: {{.*}} +; TUNIT: {{.*}} -- 2.7.4