From c68b560be381e831fd72c6b8b8909427e4e2ff36 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?D=C3=A1vid=20Bolvansk=C3=BD?= Date: Wed, 10 Mar 2021 17:51:39 +0100 Subject: [PATCH] [DSE] Handle memmove with equal non-const sizes Follow up for fhahn's D98284. Also fixes a case from PR47644. Reviewed By: fhahn Differential Revision: https://reviews.llvm.org/D98346 --- .../Scalar/DeadStoreElimination.cpp | 24 +-- .../memory-intrinsics-sizes.ll | 150 ++++++++++++++++++ 2 files changed, 158 insertions(+), 16 deletions(-) diff --git a/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp b/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp index 61cc4e3b06a3..9cf9760c074e 100644 --- a/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp +++ b/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp @@ -373,22 +373,14 @@ isOverwrite(const Instruction *LaterI, const Instruction *EarlierI, if (!Later.Size.isPrecise() || !Earlier.Size.isPrecise()) { // In case no constant size is known, try to an IR values for the number // of bytes written and check if they match. - auto GetSizeFromInstr = [](const Instruction *I) -> Value * { - if (const IntrinsicInst *II = dyn_cast(I)) { - switch (II->getIntrinsicID()) { - default: - return nullptr; - case Intrinsic::memcpy: - case Intrinsic::memset: - return II->getArgOperand(2); - } - } - return nullptr; - }; - Value *LaterV = GetSizeFromInstr(LaterI); - Value *EarlierV = GetSizeFromInstr(EarlierI); - if (LaterV && LaterV == EarlierV && AA.isMustAlias(Earlier, Later)) - return OW_Complete; + const auto *LaterMemI = dyn_cast(LaterI); + const auto *EarlierMemI = dyn_cast(EarlierI); + if (LaterMemI && EarlierMemI) { + const Value *LaterV = LaterMemI->getLength(); + const Value *EarlierV = EarlierMemI->getLength(); + if (LaterV == EarlierV && AA.isMustAlias(Earlier, Later)) + return OW_Complete; + } // Masked stores have imprecise locations, but we can reason about them // to some extent. diff --git a/llvm/test/Transforms/DeadStoreElimination/memory-intrinsics-sizes.ll b/llvm/test/Transforms/DeadStoreElimination/memory-intrinsics-sizes.ll index 412ae6569154..944a08d56ae3 100644 --- a/llvm/test/Transforms/DeadStoreElimination/memory-intrinsics-sizes.ll +++ b/llvm/test/Transforms/DeadStoreElimination/memory-intrinsics-sizes.ll @@ -199,5 +199,155 @@ define void @memcpy_and_memset_different_size_values_3(i8* noalias %src, i8* noa ret void } +define void @memmove_equal_size_values(i8* noalias %src, i8* noalias %dst, i64 %len) { +; CHECK-LABEL: @memmove_equal_size_values( +; CHECK-NEXT: call void @llvm.memmove.p0i8.p0i8.i64(i8* [[DST:%.*]], i8* [[SRC:%.*]], i64 [[LEN:%.*]], i1 false) +; CHECK-NEXT: ret void +; + call void @llvm.memmove.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 %len, i1 false) + call void @llvm.memmove.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 %len, i1 false) + ret void +} + +define void @memmove_different_size_values_1(i8* noalias %src, i8* noalias %dst, i64 %len.1, i64 %len.2) { +; CHECK-LABEL: @memmove_different_size_values_1( +; CHECK-NEXT: call void @llvm.memmove.p0i8.p0i8.i64(i8* [[DST:%.*]], i8* [[SRC:%.*]], i64 [[LEN_1:%.*]], i1 false) +; CHECK-NEXT: call void @llvm.memmove.p0i8.p0i8.i64(i8* [[DST]], i8* [[SRC]], i64 [[LEN_2:%.*]], i1 false) +; CHECK-NEXT: ret void +; + call void @llvm.memmove.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 %len.1, i1 false) + call void @llvm.memmove.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 %len.2, i1 false) + ret void +} + +define void @memmove_different_size_values_2(i8* noalias %src, i8* noalias %dst, i64 %len) { +; CHECK-LABEL: @memmove_different_size_values_2( +; CHECK-NEXT: call void @llvm.memmove.p0i8.p0i8.i64(i8* [[DST:%.*]], i8* [[SRC:%.*]], i64 [[LEN:%.*]], i1 false) +; CHECK-NEXT: call void @llvm.memmove.p0i8.p0i8.i64(i8* [[DST]], i8* [[SRC]], i64 100, i1 false) +; CHECK-NEXT: ret void +; + call void @llvm.memmove.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 %len, i1 false) + call void @llvm.memmove.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 100, i1 false) + ret void +} + +define void @memmove_different_size_values_3(i8* noalias %src, i8* noalias %dst, i64 %len) { +; CHECK-LABEL: @memmove_different_size_values_3( +; CHECK-NEXT: call void @llvm.memmove.p0i8.p0i8.i64(i8* [[DST:%.*]], i8* [[SRC:%.*]], i64 100, i1 false) +; CHECK-NEXT: call void @llvm.memmove.p0i8.p0i8.i64(i8* [[DST]], i8* [[SRC]], i64 [[LEN:%.*]], i1 false) +; CHECK-NEXT: ret void +; + call void @llvm.memmove.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 100, i1 false) + call void @llvm.memmove.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 %len, i1 false) + ret void +} + +define void @memset_and_memmove_equal_size_values(i8* noalias %src, i8* noalias %dst, i64 %len) { +; CHECK-LABEL: @memset_and_memmove_equal_size_values( +; CHECK-NEXT: call void @llvm.memmove.p0i8.p0i8.i64(i8* [[DST:%.*]], i8* [[SRC:%.*]], i64 [[LEN:%.*]], i1 false) +; CHECK-NEXT: ret void +; + call void @llvm.memset.p0i8.i64(i8* align 1 %dst, i8 0, i64 %len, i1 false) + call void @llvm.memmove.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 %len, i1 false) + ret void +} + +define void @memset_and_memmove_different_size_values_1(i8* noalias %src, i8* noalias %dst, i64 %len.1, i64 %len.2) { +; CHECK-LABEL: @memset_and_memmove_different_size_values_1( +; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* align 1 [[DST:%.*]], i8 0, i64 [[LEN_1:%.*]], i1 false) +; CHECK-NEXT: call void @llvm.memmove.p0i8.p0i8.i64(i8* [[DST]], i8* [[SRC:%.*]], i64 [[LEN_2:%.*]], i1 false) +; CHECK-NEXT: ret void +; + call void @llvm.memset.p0i8.i64(i8* align 1 %dst, i8 0, i64 %len.1, i1 false) + call void @llvm.memmove.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 %len.2, i1 false) + ret void +} + +define void @memset_and_memmove_different_size_values_2(i8* noalias %src, i8* noalias %dst, i64 %len.1) { +; CHECK-LABEL: @memset_and_memmove_different_size_values_2( +; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* align 1 [[DST:%.*]], i8 0, i64 [[LEN_1:%.*]], i1 false) +; CHECK-NEXT: call void @llvm.memmove.p0i8.p0i8.i64(i8* [[DST]], i8* [[SRC:%.*]], i64 100, i1 false) +; CHECK-NEXT: ret void +; + call void @llvm.memset.p0i8.i64(i8* align 1 %dst, i8 0, i64 %len.1, i1 false) + call void @llvm.memmove.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 100, i1 false) + ret void +} + +define void @memset_and_memmove_different_size_values_3(i8* noalias %src, i8* noalias %dst, i64 %len.1) { +; CHECK-LABEL: @memset_and_memmove_different_size_values_3( +; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* align 1 [[DST:%.*]], i8 0, i64 100, i1 false) +; CHECK-NEXT: call void @llvm.memmove.p0i8.p0i8.i64(i8* [[DST]], i8* [[SRC:%.*]], i64 [[LEN_1:%.*]], i1 false) +; CHECK-NEXT: ret void +; + call void @llvm.memset.p0i8.i64(i8* align 1 %dst, i8 0, i64 100, i1 false) + call void @llvm.memmove.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 %len.1, i1 false) + ret void +} + +define void @memmove_and_memset_equal_size_values(i8* noalias %src, i8* noalias %dst, i64 %len) { +; CHECK-LABEL: @memmove_and_memset_equal_size_values( +; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* align 1 [[DST:%.*]], i8 0, i64 [[LEN:%.*]], i1 false) +; CHECK-NEXT: ret void +; + call void @llvm.memmove.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 %len, i1 false) + call void @llvm.memset.p0i8.i64(i8* align 1 %dst, i8 0, i64 %len, i1 false) + ret void +} + +define void @memmove_and_memset_different_size_values_1(i8* noalias %src, i8* noalias %dst, i64 %len.1, i64 %len.2) { +; CHECK-LABEL: @memmove_and_memset_different_size_values_1( +; CHECK-NEXT: call void @llvm.memmove.p0i8.p0i8.i64(i8* [[DST:%.*]], i8* [[SRC:%.*]], i64 [[LEN_1:%.*]], i1 false) +; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* align 1 [[DST]], i8 0, i64 [[LEN_2:%.*]], i1 false) +; CHECK-NEXT: ret void +; + call void @llvm.memmove.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 %len.1, i1 false) + call void @llvm.memset.p0i8.i64(i8* align 1 %dst, i8 0, i64 %len.2, i1 false) + ret void +} + +define void @memmove_and_memset_different_size_values_2(i8* noalias %src, i8* noalias %dst, i64 %len.1) { +; CHECK-LABEL: @memmove_and_memset_different_size_values_2( +; CHECK-NEXT: call void @llvm.memmove.p0i8.p0i8.i64(i8* [[DST:%.*]], i8* [[SRC:%.*]], i64 [[LEN_1:%.*]], i1 false) +; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* align 1 [[DST]], i8 0, i64 100, i1 false) +; CHECK-NEXT: ret void +; + call void @llvm.memmove.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 %len.1, i1 false) + call void @llvm.memset.p0i8.i64(i8* align 1 %dst, i8 0, i64 100, i1 false) + ret void +} + +define void @memmove_and_memset_different_size_values_3(i8* noalias %src, i8* noalias %dst, i64 %len.1) { +; CHECK-LABEL: @memmove_and_memset_different_size_values_3( +; CHECK-NEXT: call void @llvm.memmove.p0i8.p0i8.i64(i8* [[DST:%.*]], i8* [[SRC:%.*]], i64 100, i1 false) +; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* align 1 [[DST]], i8 0, i64 [[LEN_1:%.*]], i1 false) +; CHECK-NEXT: ret void +; + call void @llvm.memmove.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 100, i1 false) + call void @llvm.memset.p0i8.i64(i8* align 1 %dst, i8 0, i64 %len.1, i1 false) + ret void +} + +define void @memmove_and_memcpy_equal_size_values(i8* noalias %src, i8* noalias %dst, i64 %len) { +; CHECK-LABEL: @memmove_and_memcpy_equal_size_values( +; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* [[DST:%.*]], i8* [[SRC:%.*]], i64 [[LEN:%.*]], i1 false) +; CHECK-NEXT: ret void +; + call void @llvm.memmove.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 %len, i1 false) + call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 %len, i1 false) + ret void +} + +define void @memcpy_and_memmove_equal_size_values(i8* noalias %src, i8* noalias %dst, i64 %len) { +; CHECK-LABEL: @memcpy_and_memmove_equal_size_values( +; CHECK-NEXT: call void @llvm.memmove.p0i8.p0i8.i64(i8* [[DST:%.*]], i8* [[SRC:%.*]], i64 [[LEN:%.*]], i1 false) +; CHECK-NEXT: ret void +; + call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 %len, i1 false) + call void @llvm.memmove.p0i8.p0i8.i64(i8* %dst, i8* %src, i64 %len, i1 false) + ret void +} + declare void @llvm.memset.p0i8.i64(i8* nocapture writeonly, i8, i64, i1 immarg) declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i1) +declare void @llvm.memmove.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i1)