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llvm/SOURCES/0001-SelectionDAG-Avoid-aliasing-analysis-if-the-object-s.patch
CentOS Sources 2ae2453e20 import llvm-11.0.1-2.module+el8.4.0+12666+0fb5828f
2021-11-02 17:02:24 +00:00

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From 153232761304a2746ea9a11d9da3aa5e5a7c26d0 Mon Sep 17 00:00:00 2001
From: Hsiangkai Wang <kai.wang@sifive.com>
Date: Fri, 20 Nov 2020 08:52:03 +0800
Subject: [PATCH] [SelectionDAG] Avoid aliasing analysis if the object size is
unknown.
If the size of memory access is unknown, do not use it to analysis. One
example of unknown size memory access is to load/store scalable vector
objects on the stack.
Differential Revision: https://reviews.llvm.org/D91833
---
.../SelectionDAGAddressAnalysis.cpp | 31 +-
llvm/unittests/CodeGen/CMakeLists.txt | 1 +
.../SelectionDAGAddressAnalysisTest.cpp | 337 ++++++++++++++++++
3 files changed, 359 insertions(+), 10 deletions(-)
create mode 100644 llvm/unittests/CodeGen/SelectionDAGAddressAnalysisTest.cpp
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp
index 3a53ab9717a4..20c7d771bfb6 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp
@@ -7,6 +7,7 @@
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/SelectionDAGAddressAnalysis.h"
+#include "llvm/Analysis/MemoryLocation.h"
#include "llvm/CodeGen/ISDOpcodes.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
@@ -96,18 +97,28 @@ bool BaseIndexOffset::computeAliasing(const SDNode *Op0,
int64_t PtrDiff;
if (NumBytes0.hasValue() && NumBytes1.hasValue() &&
BasePtr0.equalBaseIndex(BasePtr1, DAG, PtrDiff)) {
+ // If the size of memory access is unknown, do not use it to analysis.
+ // One example of unknown size memory access is to load/store scalable
+ // vector objects on the stack.
// BasePtr1 is PtrDiff away from BasePtr0. They alias if none of the
// following situations arise:
- IsAlias = !(
- // [----BasePtr0----]
- // [---BasePtr1--]
- // ========PtrDiff========>
- (*NumBytes0 <= PtrDiff) ||
- // [----BasePtr0----]
- // [---BasePtr1--]
- // =====(-PtrDiff)====>
- (PtrDiff + *NumBytes1 <= 0)); // i.e. *NumBytes1 < -PtrDiff.
- return true;
+ if (PtrDiff >= 0 &&
+ *NumBytes0 != static_cast<int64_t>(MemoryLocation::UnknownSize)) {
+ // [----BasePtr0----]
+ // [---BasePtr1--]
+ // ========PtrDiff========>
+ IsAlias = !(*NumBytes0 <= PtrDiff);
+ return true;
+ }
+ if (PtrDiff < 0 &&
+ *NumBytes1 != static_cast<int64_t>(MemoryLocation::UnknownSize)) {
+ // [----BasePtr0----]
+ // [---BasePtr1--]
+ // =====(-PtrDiff)====>
+ IsAlias = !((PtrDiff + *NumBytes1) <= 0);
+ return true;
+ }
+ return false;
}
// If both BasePtr0 and BasePtr1 are FrameIndexes, we will not be
// able to calculate their relative offset if at least one arises
diff --git a/llvm/unittests/CodeGen/CMakeLists.txt b/llvm/unittests/CodeGen/CMakeLists.txt
index fa3cb1fa7669..2fe525f1b413 100644
--- a/llvm/unittests/CodeGen/CMakeLists.txt
+++ b/llvm/unittests/CodeGen/CMakeLists.txt
@@ -21,6 +21,7 @@ add_llvm_unittest(CodeGenTests
MachineInstrTest.cpp
MachineOperandTest.cpp
ScalableVectorMVTsTest.cpp
+ SelectionDAGAddressAnalysisTest.cpp
TypeTraitsTest.cpp
TargetOptionsTest.cpp
)
diff --git a/llvm/unittests/CodeGen/SelectionDAGAddressAnalysisTest.cpp b/llvm/unittests/CodeGen/SelectionDAGAddressAnalysisTest.cpp
new file mode 100644
index 000000000000..c00b6c518e70
--- /dev/null
+++ b/llvm/unittests/CodeGen/SelectionDAGAddressAnalysisTest.cpp
@@ -0,0 +1,337 @@
+//===- llvm/unittest/CodeGen/SelectionDAGAddressAnalysisTest.cpp ---------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/SelectionDAGAddressAnalysis.h"
+#include "llvm/Analysis/MemoryLocation.h"
+#include "llvm/Analysis/OptimizationRemarkEmitter.h"
+#include "llvm/AsmParser/Parser.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/CodeGen/SelectionDAG.h"
+#include "llvm/CodeGen/TargetLowering.h"
+#include "llvm/Support/SourceMgr.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Support/TargetSelect.h"
+#include "llvm/Target/TargetMachine.h"
+#include "gtest/gtest.h"
+
+namespace llvm {
+
+class SelectionDAGAddressAnalysisTest : public testing::Test {
+protected:
+ static void SetUpTestCase() {
+ InitializeAllTargets();
+ InitializeAllTargetMCs();
+ }
+
+ void SetUp() override {
+ StringRef Assembly = "@g = global i32 0\n"
+ "define i32 @f() {\n"
+ " %1 = load i32, i32* @g\n"
+ " ret i32 %1\n"
+ "}";
+
+ Triple TargetTriple("aarch64--");
+ std::string Error;
+ const Target *T = TargetRegistry::lookupTarget("", TargetTriple, Error);
+ // FIXME: These tests do not depend on AArch64 specifically, but we have to
+ // initialize a target. A skeleton Target for unittests would allow us to
+ // always run these tests.
+ if (!T)
+ return;
+
+ TargetOptions Options;
+ TM = std::unique_ptr<LLVMTargetMachine>(static_cast<LLVMTargetMachine *>(
+ T->createTargetMachine("AArch64", "", "+sve", Options, None, None,
+ CodeGenOpt::Aggressive)));
+ if (!TM)
+ return;
+
+ SMDiagnostic SMError;
+ M = parseAssemblyString(Assembly, SMError, Context);
+ if (!M)
+ report_fatal_error(SMError.getMessage());
+ M->setDataLayout(TM->createDataLayout());
+
+ F = M->getFunction("f");
+ if (!F)
+ report_fatal_error("F?");
+ G = M->getGlobalVariable("g");
+ if (!G)
+ report_fatal_error("G?");
+
+ MachineModuleInfo MMI(TM.get());
+
+ MF = std::make_unique<MachineFunction>(*F, *TM, *TM->getSubtargetImpl(*F),
+ 0, MMI);
+
+ DAG = std::make_unique<SelectionDAG>(*TM, CodeGenOpt::None);
+ if (!DAG)
+ report_fatal_error("DAG?");
+ OptimizationRemarkEmitter ORE(F);
+ DAG->init(*MF, ORE, nullptr, nullptr, nullptr, nullptr, nullptr);
+ }
+
+ TargetLoweringBase::LegalizeTypeAction getTypeAction(EVT VT) {
+ return DAG->getTargetLoweringInfo().getTypeAction(Context, VT);
+ }
+
+ EVT getTypeToTransformTo(EVT VT) {
+ return DAG->getTargetLoweringInfo().getTypeToTransformTo(Context, VT);
+ }
+
+ LLVMContext Context;
+ std::unique_ptr<LLVMTargetMachine> TM;
+ std::unique_ptr<Module> M;
+ Function *F;
+ GlobalVariable *G;
+ std::unique_ptr<MachineFunction> MF;
+ std::unique_ptr<SelectionDAG> DAG;
+};
+
+TEST_F(SelectionDAGAddressAnalysisTest, sameFrameObject) {
+ if (!TM)
+ return;
+ SDLoc Loc;
+ auto Int8VT = EVT::getIntegerVT(Context, 8);
+ auto VecVT = EVT::getVectorVT(Context, Int8VT, 4);
+ SDValue FIPtr = DAG->CreateStackTemporary(VecVT);
+ int FI = cast<FrameIndexSDNode>(FIPtr.getNode())->getIndex();
+ MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(*MF, FI);
+ TypeSize Offset = TypeSize::Fixed(0);
+ SDValue Value = DAG->getConstant(0, Loc, VecVT);
+ SDValue Index = DAG->getMemBasePlusOffset(FIPtr, Offset, Loc);
+ SDValue Store = DAG->getStore(DAG->getEntryNode(), Loc, Value, Index,
+ PtrInfo.getWithOffset(Offset));
+ Optional<int64_t> NumBytes = MemoryLocation::getSizeOrUnknown(
+ cast<StoreSDNode>(Store)->getMemoryVT().getStoreSize());
+
+ bool IsAlias;
+ bool IsValid = BaseIndexOffset::computeAliasing(
+ Store.getNode(), NumBytes, Store.getNode(), NumBytes, *DAG, IsAlias);
+
+ EXPECT_TRUE(IsValid);
+ EXPECT_TRUE(IsAlias);
+}
+
+TEST_F(SelectionDAGAddressAnalysisTest, noAliasingFrameObjects) {
+ if (!TM)
+ return;
+ SDLoc Loc;
+ auto Int8VT = EVT::getIntegerVT(Context, 8);
+ // <4 x i8>
+ auto VecVT = EVT::getVectorVT(Context, Int8VT, 4);
+ // <2 x i8>
+ auto SubVecVT = EVT::getVectorVT(Context, Int8VT, 2);
+ SDValue FIPtr = DAG->CreateStackTemporary(VecVT);
+ int FI = cast<FrameIndexSDNode>(FIPtr.getNode())->getIndex();
+ MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(*MF, FI);
+ SDValue Value = DAG->getConstant(0, Loc, SubVecVT);
+ TypeSize Offset0 = TypeSize::Fixed(0);
+ TypeSize Offset1 = SubVecVT.getStoreSize();
+ SDValue Index0 = DAG->getMemBasePlusOffset(FIPtr, Offset0, Loc);
+ SDValue Index1 = DAG->getMemBasePlusOffset(FIPtr, Offset1, Loc);
+ SDValue Store0 = DAG->getStore(DAG->getEntryNode(), Loc, Value, Index0,
+ PtrInfo.getWithOffset(Offset0));
+ SDValue Store1 = DAG->getStore(DAG->getEntryNode(), Loc, Value, Index1,
+ PtrInfo.getWithOffset(Offset1));
+ Optional<int64_t> NumBytes0 = MemoryLocation::getSizeOrUnknown(
+ cast<StoreSDNode>(Store0)->getMemoryVT().getStoreSize());
+ Optional<int64_t> NumBytes1 = MemoryLocation::getSizeOrUnknown(
+ cast<StoreSDNode>(Store1)->getMemoryVT().getStoreSize());
+
+ bool IsAlias;
+ bool IsValid = BaseIndexOffset::computeAliasing(
+ Store0.getNode(), NumBytes0, Store1.getNode(), NumBytes1, *DAG, IsAlias);
+
+ EXPECT_TRUE(IsValid);
+ EXPECT_FALSE(IsAlias);
+}
+
+TEST_F(SelectionDAGAddressAnalysisTest, unknownSizeFrameObjects) {
+ if (!TM)
+ return;
+ SDLoc Loc;
+ auto Int8VT = EVT::getIntegerVT(Context, 8);
+ // <vscale x 4 x i8>
+ auto VecVT = EVT::getVectorVT(Context, Int8VT, 4, true);
+ // <vscale x 2 x i8>
+ auto SubVecVT = EVT::getVectorVT(Context, Int8VT, 2, true);
+ SDValue FIPtr = DAG->CreateStackTemporary(VecVT);
+ int FI = cast<FrameIndexSDNode>(FIPtr.getNode())->getIndex();
+ MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(*MF, FI);
+ SDValue Value = DAG->getConstant(0, Loc, SubVecVT);
+ TypeSize Offset0 = TypeSize::Fixed(0);
+ TypeSize Offset1 = SubVecVT.getStoreSize();
+ SDValue Index0 = DAG->getMemBasePlusOffset(FIPtr, Offset0, Loc);
+ SDValue Index1 = DAG->getMemBasePlusOffset(FIPtr, Offset1, Loc);
+ SDValue Store0 = DAG->getStore(DAG->getEntryNode(), Loc, Value, Index0,
+ PtrInfo.getWithOffset(Offset0));
+ SDValue Store1 = DAG->getStore(DAG->getEntryNode(), Loc, Value, Index1,
+ PtrInfo.getWithOffset(Offset1));
+ Optional<int64_t> NumBytes0 = MemoryLocation::getSizeOrUnknown(
+ cast<StoreSDNode>(Store0)->getMemoryVT().getStoreSize());
+ Optional<int64_t> NumBytes1 = MemoryLocation::getSizeOrUnknown(
+ cast<StoreSDNode>(Store1)->getMemoryVT().getStoreSize());
+
+ bool IsAlias;
+ bool IsValid = BaseIndexOffset::computeAliasing(
+ Store0.getNode(), NumBytes0, Store1.getNode(), NumBytes1, *DAG, IsAlias);
+
+ EXPECT_FALSE(IsValid);
+}
+
+TEST_F(SelectionDAGAddressAnalysisTest, globalWithFrameObject) {
+ if (!TM)
+ return;
+ SDLoc Loc;
+ auto Int8VT = EVT::getIntegerVT(Context, 8);
+ // <vscale x 4 x i8>
+ auto VecVT = EVT::getVectorVT(Context, Int8VT, 4, true);
+ SDValue FIPtr = DAG->CreateStackTemporary(VecVT);
+ int FI = cast<FrameIndexSDNode>(FIPtr.getNode())->getIndex();
+ MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(*MF, FI);
+ SDValue Value = DAG->getConstant(0, Loc, VecVT);
+ TypeSize Offset = TypeSize::Fixed(0);
+ SDValue Index = DAG->getMemBasePlusOffset(FIPtr, Offset, Loc);
+ SDValue Store = DAG->getStore(DAG->getEntryNode(), Loc, Value, Index,
+ PtrInfo.getWithOffset(Offset));
+ Optional<int64_t> NumBytes = MemoryLocation::getSizeOrUnknown(
+ cast<StoreSDNode>(Store)->getMemoryVT().getStoreSize());
+ EVT GTy = DAG->getTargetLoweringInfo().getValueType(DAG->getDataLayout(),
+ G->getType());
+ SDValue GValue = DAG->getConstant(0, Loc, GTy);
+ SDValue GAddr = DAG->getGlobalAddress(G, Loc, GTy);
+ SDValue GStore = DAG->getStore(DAG->getEntryNode(), Loc, GValue, GAddr,
+ MachinePointerInfo(G, 0));
+ Optional<int64_t> GNumBytes = MemoryLocation::getSizeOrUnknown(
+ cast<StoreSDNode>(GStore)->getMemoryVT().getStoreSize());
+
+ bool IsAlias;
+ bool IsValid = BaseIndexOffset::computeAliasing(
+ Store.getNode(), NumBytes, GStore.getNode(), GNumBytes, *DAG, IsAlias);
+
+ EXPECT_TRUE(IsValid);
+ EXPECT_FALSE(IsAlias);
+}
+
+TEST_F(SelectionDAGAddressAnalysisTest, fixedSizeFrameObjectsWithinDiff) {
+ if (!TM)
+ return;
+ SDLoc Loc;
+ auto Int8VT = EVT::getIntegerVT(Context, 8);
+ // <vscale x 4 x i8>
+ auto VecVT = EVT::getVectorVT(Context, Int8VT, 4, true);
+ // <vscale x 2 x i8>
+ auto SubVecVT = EVT::getVectorVT(Context, Int8VT, 2, true);
+ // <2 x i8>
+ auto SubFixedVecVT2xi8 = EVT::getVectorVT(Context, Int8VT, 2);
+ SDValue FIPtr = DAG->CreateStackTemporary(VecVT);
+ int FI = cast<FrameIndexSDNode>(FIPtr.getNode())->getIndex();
+ MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(*MF, FI);
+ SDValue Value0 = DAG->getConstant(0, Loc, SubFixedVecVT2xi8);
+ SDValue Value1 = DAG->getConstant(0, Loc, SubVecVT);
+ TypeSize Offset0 = TypeSize::Fixed(0);
+ TypeSize Offset1 = SubFixedVecVT2xi8.getStoreSize();
+ SDValue Index0 = DAG->getMemBasePlusOffset(FIPtr, Offset0, Loc);
+ SDValue Index1 = DAG->getMemBasePlusOffset(FIPtr, Offset1, Loc);
+ SDValue Store0 = DAG->getStore(DAG->getEntryNode(), Loc, Value0, Index0,
+ PtrInfo.getWithOffset(Offset0));
+ SDValue Store1 = DAG->getStore(DAG->getEntryNode(), Loc, Value1, Index1,
+ PtrInfo.getWithOffset(Offset1));
+ Optional<int64_t> NumBytes0 = MemoryLocation::getSizeOrUnknown(
+ cast<StoreSDNode>(Store0)->getMemoryVT().getStoreSize());
+ Optional<int64_t> NumBytes1 = MemoryLocation::getSizeOrUnknown(
+ cast<StoreSDNode>(Store1)->getMemoryVT().getStoreSize());
+
+ bool IsAlias;
+ bool IsValid = BaseIndexOffset::computeAliasing(
+ Store0.getNode(), NumBytes0, Store1.getNode(), NumBytes1, *DAG, IsAlias);
+ EXPECT_TRUE(IsValid);
+ EXPECT_FALSE(IsAlias);
+
+ IsValid = BaseIndexOffset::computeAliasing(
+ Store1.getNode(), NumBytes1, Store0.getNode(), NumBytes0, *DAG, IsAlias);
+ EXPECT_TRUE(IsValid);
+ EXPECT_FALSE(IsAlias);
+}
+
+TEST_F(SelectionDAGAddressAnalysisTest, fixedSizeFrameObjectsOutOfDiff) {
+ if (!TM)
+ return;
+ SDLoc Loc;
+ auto Int8VT = EVT::getIntegerVT(Context, 8);
+ // <vscale x 4 x i8>
+ auto VecVT = EVT::getVectorVT(Context, Int8VT, 4, true);
+ // <vscale x 2 x i8>
+ auto SubVecVT = EVT::getVectorVT(Context, Int8VT, 2, true);
+ // <2 x i8>
+ auto SubFixedVecVT2xi8 = EVT::getVectorVT(Context, Int8VT, 2);
+ // <4 x i8>
+ auto SubFixedVecVT4xi8 = EVT::getVectorVT(Context, Int8VT, 4);
+ SDValue FIPtr = DAG->CreateStackTemporary(VecVT);
+ int FI = cast<FrameIndexSDNode>(FIPtr.getNode())->getIndex();
+ MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(*MF, FI);
+ SDValue Value0 = DAG->getConstant(0, Loc, SubFixedVecVT4xi8);
+ SDValue Value1 = DAG->getConstant(0, Loc, SubVecVT);
+ TypeSize Offset0 = TypeSize::Fixed(0);
+ TypeSize Offset1 = SubFixedVecVT2xi8.getStoreSize();
+ SDValue Index0 = DAG->getMemBasePlusOffset(FIPtr, Offset0, Loc);
+ SDValue Index1 = DAG->getMemBasePlusOffset(FIPtr, Offset1, Loc);
+ SDValue Store0 = DAG->getStore(DAG->getEntryNode(), Loc, Value0, Index0,
+ PtrInfo.getWithOffset(Offset0));
+ SDValue Store1 = DAG->getStore(DAG->getEntryNode(), Loc, Value1, Index1,
+ PtrInfo.getWithOffset(Offset1));
+ Optional<int64_t> NumBytes0 = MemoryLocation::getSizeOrUnknown(
+ cast<StoreSDNode>(Store0)->getMemoryVT().getStoreSize());
+ Optional<int64_t> NumBytes1 = MemoryLocation::getSizeOrUnknown(
+ cast<StoreSDNode>(Store1)->getMemoryVT().getStoreSize());
+
+ bool IsAlias;
+ bool IsValid = BaseIndexOffset::computeAliasing(
+ Store0.getNode(), NumBytes0, Store1.getNode(), NumBytes1, *DAG, IsAlias);
+ EXPECT_TRUE(IsValid);
+ EXPECT_TRUE(IsAlias);
+}
+
+TEST_F(SelectionDAGAddressAnalysisTest, twoFixedStackObjects) {
+ if (!TM)
+ return;
+ SDLoc Loc;
+ auto Int8VT = EVT::getIntegerVT(Context, 8);
+ // <vscale x 2 x i8>
+ auto VecVT = EVT::getVectorVT(Context, Int8VT, 2, true);
+ // <2 x i8>
+ auto FixedVecVT = EVT::getVectorVT(Context, Int8VT, 2);
+ SDValue FIPtr0 = DAG->CreateStackTemporary(FixedVecVT);
+ SDValue FIPtr1 = DAG->CreateStackTemporary(VecVT);
+ int FI0 = cast<FrameIndexSDNode>(FIPtr0.getNode())->getIndex();
+ int FI1 = cast<FrameIndexSDNode>(FIPtr1.getNode())->getIndex();
+ MachinePointerInfo PtrInfo0 = MachinePointerInfo::getFixedStack(*MF, FI0);
+ MachinePointerInfo PtrInfo1 = MachinePointerInfo::getFixedStack(*MF, FI1);
+ SDValue Value0 = DAG->getConstant(0, Loc, FixedVecVT);
+ SDValue Value1 = DAG->getConstant(0, Loc, VecVT);
+ TypeSize Offset0 = TypeSize::Fixed(0);
+ SDValue Index0 = DAG->getMemBasePlusOffset(FIPtr0, Offset0, Loc);
+ SDValue Index1 = DAG->getMemBasePlusOffset(FIPtr1, Offset0, Loc);
+ SDValue Store0 = DAG->getStore(DAG->getEntryNode(), Loc, Value0, Index0,
+ PtrInfo0.getWithOffset(Offset0));
+ SDValue Store1 = DAG->getStore(DAG->getEntryNode(), Loc, Value1, Index1,
+ PtrInfo1.getWithOffset(Offset0));
+ Optional<int64_t> NumBytes0 = MemoryLocation::getSizeOrUnknown(
+ cast<StoreSDNode>(Store0)->getMemoryVT().getStoreSize());
+ Optional<int64_t> NumBytes1 = MemoryLocation::getSizeOrUnknown(
+ cast<StoreSDNode>(Store1)->getMemoryVT().getStoreSize());
+
+ bool IsAlias;
+ bool IsValid = BaseIndexOffset::computeAliasing(
+ Store0.getNode(), NumBytes0, Store1.getNode(), NumBytes1, *DAG, IsAlias);
+ EXPECT_TRUE(IsValid);
+ EXPECT_FALSE(IsAlias);
+}
+
+} // end namespace llvm
--
2.26.2
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