[llvm] r355537 - Revert "[IR][ARM] Add function pointer alignment to datalayout"
Mitch Phillips via llvm-commits
llvm-commits at lists.llvm.org
Wed Mar 6 11:17:18 PST 2019
Author: hctim
Date: Wed Mar 6 11:17:18 2019
New Revision: 355537
URL: http://llvm.org/viewvc/llvm-project?rev=355537&view=rev
Log:
Revert "[IR][ARM] Add function pointer alignment to datalayout"
This reverts commit 2391bfca97290181ae65796ea6da135d1b6d037b.
This reverts rL355522 (https://reviews.llvm.org/D57335).
Kills buildbots that use '-Werror' with the following error:
/var/lib/buildbot/sanitizer-buildbot6/sanitizer-x86_64-linux-android/build/llvm/lib/IR/Value.cpp:657:7: error: default label in switch which covers all enumeration values [-Werror,-Wcovered-switch-default]
See buildbots http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/30200/steps/check-llvm%20asan/logs/stdio for more information.
Removed:
llvm/trunk/unittests/IR/DataLayoutTest.cpp
Modified:
llvm/trunk/docs/LangRef.rst
llvm/trunk/include/llvm/IR/DataLayout.h
llvm/trunk/lib/IR/ConstantFold.cpp
llvm/trunk/lib/IR/DataLayout.cpp
llvm/trunk/lib/IR/Value.cpp
llvm/trunk/lib/Target/ARM/ARMTargetMachine.cpp
llvm/trunk/unittests/IR/CMakeLists.txt
llvm/trunk/unittests/IR/ConstantsTest.cpp
llvm/trunk/unittests/IR/FunctionTest.cpp
Modified: llvm/trunk/docs/LangRef.rst
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/LangRef.rst?rev=355537&r1=355536&r2=355537&view=diff
==============================================================================
--- llvm/trunk/docs/LangRef.rst (original)
+++ llvm/trunk/docs/LangRef.rst Wed Mar 6 11:17:18 2019
@@ -2004,14 +2004,6 @@ as follows:
targets.
``a:<abi>:<pref>``
This specifies the alignment for an object of aggregate type.
-``F<type><abi>``
- This specifies the alignment for function pointers.
- The options for ``<type>`` are:
-
- * ``i``: The alignment of function pointers is independent of the alignment
- of functions, and is a multiple of ``<abi>``.
- * ``n``: The alignment of function pointers is a multiple of the explicit
- alignment specified on the function, and is a multiple of ``<abi>``.
``m:<mangling>``
If present, specifies that llvm names are mangled in the output. Symbols
prefixed with the mangling escape character ``\01`` are passed through
Modified: llvm/trunk/include/llvm/IR/DataLayout.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/DataLayout.h?rev=355537&r1=355536&r2=355537&view=diff
==============================================================================
--- llvm/trunk/include/llvm/IR/DataLayout.h (original)
+++ llvm/trunk/include/llvm/IR/DataLayout.h Wed Mar 6 11:17:18 2019
@@ -108,13 +108,6 @@ struct PointerAlignElem {
/// generating LLVM IR is required to generate the right target data for the
/// target being codegen'd to.
class DataLayout {
-public:
- enum class FunctionPtrAlignType {
- /// The function pointer alignment is independent of the function alignment.
- Independent,
- /// The function pointer alignment is a multiple of the function alignment.
- MultipleOfFunctionAlign,
- };
private:
/// Defaults to false.
bool BigEndian;
@@ -123,9 +116,6 @@ private:
unsigned StackNaturalAlign;
unsigned ProgramAddrSpace;
- unsigned FunctionPtrAlign;
- FunctionPtrAlignType TheFunctionPtrAlignType;
-
enum ManglingModeT {
MM_None,
MM_ELF,
@@ -209,8 +199,6 @@ public:
BigEndian = DL.isBigEndian();
AllocaAddrSpace = DL.AllocaAddrSpace;
StackNaturalAlign = DL.StackNaturalAlign;
- FunctionPtrAlign = DL.FunctionPtrAlign;
- TheFunctionPtrAlignType = DL.TheFunctionPtrAlignType;
ProgramAddrSpace = DL.ProgramAddrSpace;
ManglingMode = DL.ManglingMode;
LegalIntWidths = DL.LegalIntWidths;
@@ -268,17 +256,6 @@ public:
unsigned getStackAlignment() const { return StackNaturalAlign; }
unsigned getAllocaAddrSpace() const { return AllocaAddrSpace; }
- /// Returns the alignment of function pointers, which may or may not be
- /// related to the alignment of functions.
- /// \see getFunctionPtrAlignType
- unsigned getFunctionPtrAlign() const { return FunctionPtrAlign; }
-
- /// Return the type of function pointer alignment.
- /// \see getFunctionPtrAlign
- FunctionPtrAlignType getFunctionPtrAlignType() const {
- return TheFunctionPtrAlignType;
- }
-
unsigned getProgramAddressSpace() const { return ProgramAddrSpace; }
bool hasMicrosoftFastStdCallMangling() const {
Modified: llvm/trunk/lib/IR/ConstantFold.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/ConstantFold.cpp?rev=355537&r1=355536&r2=355537&view=diff
==============================================================================
--- llvm/trunk/lib/IR/ConstantFold.cpp (original)
+++ llvm/trunk/lib/IR/ConstantFold.cpp Wed Mar 6 11:17:18 2019
@@ -26,7 +26,6 @@
#include "llvm/IR/GlobalAlias.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/Instructions.h"
-#include "llvm/IR/Module.h"
#include "llvm/IR/Operator.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/Support/ErrorHandling.h"
@@ -1077,29 +1076,10 @@ Constant *llvm::ConstantFoldBinaryInstru
isa<GlobalValue>(CE1->getOperand(0))) {
GlobalValue *GV = cast<GlobalValue>(CE1->getOperand(0));
- unsigned GVAlign;
-
- if (Module *TheModule = GV->getParent()) {
- GVAlign = GV->getPointerAlignment(TheModule->getDataLayout());
-
- // If the function alignment is not specified then assume that it
- // is 4.
- // This is dangerous; on x86, the alignment of the pointer
- // corresponds to the alignment of the function, but might be less
- // than 4 if it isn't explicitly specified.
- // However, a fix for this behaviour was reverted because it
- // increased code size (see https://reviews.llvm.org/D55115)
- // FIXME: This code should be deleted once existing targets have
- // appropriate defaults
- if (GVAlign == 0U && isa<Function>(GV))
- GVAlign = 4U;
- } else if (isa<Function>(GV)) {
- // Without a datalayout we have to assume the worst case: that the
- // function pointer isn't aligned at all.
- GVAlign = 0U;
- } else {
- GVAlign = GV->getAlignment();
- }
+ // Functions are at least 4-byte aligned.
+ unsigned GVAlign = GV->getAlignment();
+ if (isa<Function>(GV))
+ GVAlign = std::max(GVAlign, 4U);
if (GVAlign > 1) {
unsigned DstWidth = CI2->getType()->getBitWidth();
Modified: llvm/trunk/lib/IR/DataLayout.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/DataLayout.cpp?rev=355537&r1=355536&r2=355537&view=diff
==============================================================================
--- llvm/trunk/lib/IR/DataLayout.cpp (original)
+++ llvm/trunk/lib/IR/DataLayout.cpp Wed Mar 6 11:17:18 2019
@@ -184,8 +184,6 @@ void DataLayout::reset(StringRef Desc) {
AllocaAddrSpace = 0;
StackNaturalAlign = 0;
ProgramAddrSpace = 0;
- FunctionPtrAlign = 0;
- TheFunctionPtrAlignType = FunctionPtrAlignType::Independent;
ManglingMode = MM_None;
NonIntegralAddressSpaces.clear();
@@ -381,22 +379,6 @@ void DataLayout::parseSpecifier(StringRe
StackNaturalAlign = inBytes(getInt(Tok));
break;
}
- case 'F': {
- switch (Tok.front()) {
- case 'i':
- TheFunctionPtrAlignType = FunctionPtrAlignType::Independent;
- break;
- case 'n':
- TheFunctionPtrAlignType = FunctionPtrAlignType::MultipleOfFunctionAlign;
- break;
- default:
- report_fatal_error("Unknown function pointer alignment type in "
- "datalayout string");
- }
- Tok = Tok.substr(1);
- FunctionPtrAlign = inBytes(getInt(Tok));
- break;
- }
case 'P': { // Function address space.
ProgramAddrSpace = getAddrSpace(Tok);
break;
@@ -450,8 +432,6 @@ bool DataLayout::operator==(const DataLa
AllocaAddrSpace == Other.AllocaAddrSpace &&
StackNaturalAlign == Other.StackNaturalAlign &&
ProgramAddrSpace == Other.ProgramAddrSpace &&
- FunctionPtrAlign == Other.FunctionPtrAlign &&
- TheFunctionPtrAlignType == Other.TheFunctionPtrAlignType &&
ManglingMode == Other.ManglingMode &&
LegalIntWidths == Other.LegalIntWidths &&
Alignments == Other.Alignments && Pointers == Other.Pointers;
Modified: llvm/trunk/lib/IR/Value.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/Value.cpp?rev=355537&r1=355536&r2=355537&view=diff
==============================================================================
--- llvm/trunk/lib/IR/Value.cpp (original)
+++ llvm/trunk/lib/IR/Value.cpp Wed Mar 6 11:17:18 2019
@@ -648,16 +648,10 @@ unsigned Value::getPointerAlignment(cons
unsigned Align = 0;
if (auto *GO = dyn_cast<GlobalObject>(this)) {
- if (isa<Function>(GO)) {
- switch (DL.getFunctionPtrAlignType()) {
- case DataLayout::FunctionPtrAlignType::Independent:
- return DL.getFunctionPtrAlign();
- case DataLayout::FunctionPtrAlignType::MultipleOfFunctionAlign:
- return std::max(DL.getFunctionPtrAlign(), GO->getAlignment());
- default:
- llvm_unreachable("unknown function pointer align type");
- }
- }
+ // Don't make any assumptions about function pointer alignment. Some
+ // targets use the LSBs to store additional information.
+ if (isa<Function>(GO))
+ return 0;
Align = GO->getAlignment();
if (Align == 0) {
if (auto *GVar = dyn_cast<GlobalVariable>(GO)) {
Modified: llvm/trunk/lib/Target/ARM/ARMTargetMachine.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMTargetMachine.cpp?rev=355537&r1=355536&r2=355537&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMTargetMachine.cpp (original)
+++ llvm/trunk/lib/Target/ARM/ARMTargetMachine.cpp Wed Mar 6 11:17:18 2019
@@ -141,10 +141,6 @@ static std::string computeDataLayout(con
// Pointers are 32 bits and aligned to 32 bits.
Ret += "-p:32:32";
- // Function pointers are aligned to 8 bits (because the LSB stores the
- // ARM/Thumb state).
- Ret += "-Fi8";
-
// ABIs other than APCS have 64 bit integers with natural alignment.
if (ABI != ARMBaseTargetMachine::ARM_ABI_APCS)
Ret += "-i64:64";
Modified: llvm/trunk/unittests/IR/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/IR/CMakeLists.txt?rev=355537&r1=355536&r2=355537&view=diff
==============================================================================
--- llvm/trunk/unittests/IR/CMakeLists.txt (original)
+++ llvm/trunk/unittests/IR/CMakeLists.txt Wed Mar 6 11:17:18 2019
@@ -13,7 +13,6 @@ add_llvm_unittest(IRTests
CFGBuilder.cpp
ConstantRangeTest.cpp
ConstantsTest.cpp
- DataLayoutTest.cpp
DebugInfoTest.cpp
DebugTypeODRUniquingTest.cpp
DominatorTreeTest.cpp
Modified: llvm/trunk/unittests/IR/ConstantsTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/IR/ConstantsTest.cpp?rev=355537&r1=355536&r2=355537&view=diff
==============================================================================
--- llvm/trunk/unittests/IR/ConstantsTest.cpp (original)
+++ llvm/trunk/unittests/IR/ConstantsTest.cpp Wed Mar 6 11:17:18 2019
@@ -475,105 +475,5 @@ TEST(ConstantsTest, BitcastToGEP) {
ASSERT_EQ(cast<ConstantExpr>(C)->getOpcode(), Instruction::BitCast);
}
-bool foldFuncPtrAndConstToNull(LLVMContext &Context, Module *TheModule,
- uint64_t AndValue, unsigned FunctionAlign = 0) {
- Type *VoidType(Type::getVoidTy(Context));
- FunctionType *FuncType(FunctionType::get(VoidType, false));
- Function *Func(Function::Create(
- FuncType, GlobalValue::ExternalLinkage, "", TheModule));
-
- if (FunctionAlign) Func->setAlignment(FunctionAlign);
-
- IntegerType *ConstantIntType(Type::getInt32Ty(Context));
- ConstantInt *TheConstant(ConstantInt::get(ConstantIntType, AndValue));
-
- Constant *TheConstantExpr(
- ConstantExpr::getPtrToInt(Func, ConstantIntType));
-
- return ConstantExpr::get(Instruction::And, TheConstantExpr,
- TheConstant)->isNullValue();
-}
-
-TEST(ConstantsTest, FoldFunctionPtrAlignUnknownAnd2) {
- LLVMContext Context;
- Module TheModule("TestModule", Context);
- // When the DataLayout doesn't specify a function pointer alignment we
- // assume in this case that it is 4 byte aligned. This is a bug but we can't
- // fix it directly because it causes a code size regression on X86.
- // FIXME: This test should be changed once existing targets have
- // appropriate defaults. See associated FIXME in ConstantFoldBinaryInstruction
- ASSERT_TRUE(foldFuncPtrAndConstToNull(Context, &TheModule, 2));
-}
-
-TEST(ConstantsTest, DontFoldFunctionPtrAlignUnknownAnd4) {
- LLVMContext Context;
- Module TheModule("TestModule", Context);
- ASSERT_FALSE(foldFuncPtrAndConstToNull(Context, &TheModule, 4));
-}
-
-TEST(ConstantsTest, FoldFunctionPtrAlign4) {
- LLVMContext Context;
- Module TheModule("TestModule", Context);
- const char* AlignmentStrings[] = { "Fi32", "Fn32" };
-
- for (unsigned AndValue = 1; AndValue <= 2; ++AndValue) {
- for (const char *AlignmentString : AlignmentStrings) {
- TheModule.setDataLayout(AlignmentString);
- ASSERT_TRUE(foldFuncPtrAndConstToNull(Context, &TheModule, AndValue));
- }
- }
-}
-
-TEST(ConstantsTest, DontFoldFunctionPtrAlign1) {
- LLVMContext Context;
- Module TheModule("TestModule", Context);
- const char* AlignmentStrings[] = { "Fi8", "Fn8" };
-
- for (const char* AlignmentString : AlignmentStrings) {
- TheModule.setDataLayout(AlignmentString);
- ASSERT_FALSE(foldFuncPtrAndConstToNull(Context, &TheModule, 2));
- }
-}
-
-TEST(ConstantsTest, FoldFunctionAlign4PtrAlignMultiple) {
- LLVMContext Context;
- Module TheModule("TestModule", Context);
- TheModule.setDataLayout("Fn8");
- ASSERT_TRUE(foldFuncPtrAndConstToNull(Context, &TheModule, 2, 4));
-}
-
-TEST(ConstantsTest, DontFoldFunctionAlign4PtrAlignIndependent) {
- LLVMContext Context;
- Module TheModule("TestModule", Context);
- TheModule.setDataLayout("Fi8");
- ASSERT_FALSE(foldFuncPtrAndConstToNull(Context, &TheModule, 2, 4));
-}
-
-TEST(ConstantsTest, DontFoldFunctionPtrIfNoModule) {
- LLVMContext Context;
- // Even though the function is explicitly 4 byte aligned, in the absence of a
- // DataLayout we can't assume that the function pointer is aligned.
- ASSERT_FALSE(foldFuncPtrAndConstToNull(Context, nullptr, 2, 4));
-}
-
-TEST(ConstantsTest, FoldGlobalVariablePtr) {
- LLVMContext Context;
-
-
- IntegerType *IntType(Type::getInt32Ty(Context));
-
- GlobalVariable Global(IntType, true, GlobalValue::ExternalLinkage);
-
- Global.setAlignment(4);
-
- ConstantInt *TheConstant(ConstantInt::get(IntType, 2));
-
- Constant *TheConstantExpr(
- ConstantExpr::getPtrToInt(&Global, IntType));
-
- ASSERT_TRUE(ConstantExpr::get( \
- Instruction::And, TheConstantExpr, TheConstant)->isNullValue());
-}
-
} // end anonymous namespace
} // end namespace llvm
Removed: llvm/trunk/unittests/IR/DataLayoutTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/IR/DataLayoutTest.cpp?rev=355536&view=auto
==============================================================================
--- llvm/trunk/unittests/IR/DataLayoutTest.cpp (original)
+++ llvm/trunk/unittests/IR/DataLayoutTest.cpp (removed)
@@ -1,47 +0,0 @@
-//===- ConstantRangeTest.cpp - ConstantRange tests ------------------------===//
-//
-// 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/IR/DataLayout.h"
-#include "gtest/gtest.h"
-
-using namespace llvm;
-
-namespace {
-
-TEST(DataLayoutTest, FunctionPtrAlign) {
- EXPECT_EQ(0U, DataLayout("").getFunctionPtrAlign());
- EXPECT_EQ(1U, DataLayout("Fi8").getFunctionPtrAlign());
- EXPECT_EQ(2U, DataLayout("Fi16").getFunctionPtrAlign());
- EXPECT_EQ(4U, DataLayout("Fi32").getFunctionPtrAlign());
- EXPECT_EQ(8U, DataLayout("Fi64").getFunctionPtrAlign());
- EXPECT_EQ(1U, DataLayout("Fn8").getFunctionPtrAlign());
- EXPECT_EQ(2U, DataLayout("Fn16").getFunctionPtrAlign());
- EXPECT_EQ(4U, DataLayout("Fn32").getFunctionPtrAlign());
- EXPECT_EQ(8U, DataLayout("Fn64").getFunctionPtrAlign());
- EXPECT_EQ(DataLayout::FunctionPtrAlignType::Independent, \
- DataLayout("").getFunctionPtrAlignType());
- EXPECT_EQ(DataLayout::FunctionPtrAlignType::Independent, \
- DataLayout("Fi8").getFunctionPtrAlignType());
- EXPECT_EQ(DataLayout::FunctionPtrAlignType::MultipleOfFunctionAlign, \
- DataLayout("Fn8").getFunctionPtrAlignType());
- EXPECT_EQ(DataLayout("Fi8"), DataLayout("Fi8"));
- EXPECT_NE(DataLayout("Fi8"), DataLayout("Fi16"));
- EXPECT_NE(DataLayout("Fi8"), DataLayout("Fn8"));
-
- DataLayout a(""), b("Fi8"), c("Fn8");
- EXPECT_NE(a, b);
- EXPECT_NE(a, c);
- EXPECT_NE(b, c);
-
- a = b;
- EXPECT_EQ(a, b);
- a = c;
- EXPECT_EQ(a, c);
-}
-
-} // anonymous namespace
Modified: llvm/trunk/unittests/IR/FunctionTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/IR/FunctionTest.cpp?rev=355537&r1=355536&r2=355537&view=diff
==============================================================================
--- llvm/trunk/unittests/IR/FunctionTest.cpp (original)
+++ llvm/trunk/unittests/IR/FunctionTest.cpp Wed Mar 6 11:17:18 2019
@@ -129,29 +129,4 @@ TEST(FunctionTest, setSection) {
EXPECT_TRUE(F->hasSection());
}
-TEST(FunctionTest, GetPointerAlignment) {
- LLVMContext Context;
- Type *VoidType(Type::getVoidTy(Context));
- FunctionType *FuncType(FunctionType::get(VoidType, false));
- Function *Func = Function::Create(
- FuncType, GlobalValue::ExternalLinkage);
- EXPECT_EQ(0U, Func->getPointerAlignment(DataLayout("")));
- EXPECT_EQ(1U, Func->getPointerAlignment(DataLayout("Fi8")));
- EXPECT_EQ(1U, Func->getPointerAlignment(DataLayout("Fn8")));
- EXPECT_EQ(2U, Func->getPointerAlignment(DataLayout("Fi16")));
- EXPECT_EQ(2U, Func->getPointerAlignment(DataLayout("Fn16")));
- EXPECT_EQ(4U, Func->getPointerAlignment(DataLayout("Fi32")));
- EXPECT_EQ(4U, Func->getPointerAlignment(DataLayout("Fn32")));
-
- Func->setAlignment(4U);
-
- EXPECT_EQ(0U, Func->getPointerAlignment(DataLayout("")));
- EXPECT_EQ(1U, Func->getPointerAlignment(DataLayout("Fi8")));
- EXPECT_EQ(4U, Func->getPointerAlignment(DataLayout("Fn8")));
- EXPECT_EQ(2U, Func->getPointerAlignment(DataLayout("Fi16")));
- EXPECT_EQ(4U, Func->getPointerAlignment(DataLayout("Fn16")));
- EXPECT_EQ(4U, Func->getPointerAlignment(DataLayout("Fi32")));
- EXPECT_EQ(4U, Func->getPointerAlignment(DataLayout("Fn32")));
-}
-
} // end namespace
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