diff --git a/llvm/lib/Transforms/Utils/PromoteMemoryToRegister.cpp b/llvm/lib/Transforms/Utils/PromoteMemoryToRegister.cpp index 40d0f6b75d69b..a1210ac0f88ac 100644 --- a/llvm/lib/Transforms/Utils/PromoteMemoryToRegister.cpp +++ b/llvm/lib/Transforms/Utils/PromoteMemoryToRegister.cpp @@ -453,6 +453,15 @@ static void addAssumeNonNull(AssumptionCache *AC, LoadInst *LI) { static void convertMetadataToAssumes(LoadInst *LI, Value *Val, const DataLayout &DL, AssumptionCache *AC, const DominatorTree *DT) { + if (isa(Val) && LI->hasMetadata(LLVMContext::MD_noundef)) { + // Insert non-terminator unreachable. + LLVMContext &Ctx = LI->getContext(); + new StoreInst(ConstantInt::getTrue(Ctx), + PoisonValue::get(PointerType::getUnqual(Ctx)), + /*isVolatile=*/false, Align(1), LI); + return; + } + // If the load was marked as nonnull we don't want to lose that information // when we erase this Load. So we preserve it with an assume. As !nonnull // returns poison while assume violations are immediate undefined behavior, diff --git a/llvm/test/Transforms/Mem2Reg/preserve-nonnull-load-metadata.ll b/llvm/test/Transforms/Mem2Reg/preserve-nonnull-load-metadata.ll index e3c14cc662e2a..edc07864795e8 100644 --- a/llvm/test/Transforms/Mem2Reg/preserve-nonnull-load-metadata.ll +++ b/llvm/test/Transforms/Mem2Reg/preserve-nonnull-load-metadata.ll @@ -143,6 +143,7 @@ fin: define ptr @no_store_single_load_noundef() { ; CHECK-LABEL: @no_store_single_load_noundef( ; CHECK-NEXT: entry: +; CHECK-NEXT: store i1 true, ptr poison, align 1 ; CHECK-NEXT: ret ptr undef ; entry: @@ -156,8 +157,10 @@ define ptr @no_store_multiple_loads_noundef(i1 %c) { ; CHECK-NEXT: entry: ; CHECK-NEXT: br i1 [[C:%.*]], label [[IF:%.*]], label [[ELSE:%.*]] ; CHECK: if: +; CHECK-NEXT: store i1 true, ptr poison, align 1 ; CHECK-NEXT: ret ptr undef ; CHECK: else: +; CHECK-NEXT: store i1 true, ptr poison, align 1 ; CHECK-NEXT: ret ptr undef ; entry: @@ -176,8 +179,7 @@ if: define ptr @no_store_single_load_nonnull_noundef() { ; CHECK-LABEL: @no_store_single_load_nonnull_noundef( ; CHECK-NEXT: entry: -; CHECK-NEXT: [[TMP0:%.*]] = icmp ne ptr undef, null -; CHECK-NEXT: call void @llvm.assume(i1 [[TMP0]]) +; CHECK-NEXT: store i1 true, ptr poison, align 1 ; CHECK-NEXT: ret ptr undef ; entry: @@ -191,12 +193,10 @@ define ptr @no_store_multiple_loads_nonnull_noundef(i1 %c) { ; CHECK-NEXT: entry: ; CHECK-NEXT: br i1 [[C:%.*]], label [[IF:%.*]], label [[ELSE:%.*]] ; CHECK: if: -; CHECK-NEXT: [[TMP0:%.*]] = icmp ne ptr undef, null -; CHECK-NEXT: call void @llvm.assume(i1 [[TMP0]]) +; CHECK-NEXT: store i1 true, ptr poison, align 1 ; CHECK-NEXT: ret ptr undef ; CHECK: else: -; CHECK-NEXT: [[TMP1:%.*]] = icmp ne ptr undef, null -; CHECK-NEXT: call void @llvm.assume(i1 [[TMP1]]) +; CHECK-NEXT: store i1 true, ptr poison, align 1 ; CHECK-NEXT: ret ptr undef ; entry: