https://github.com/JonPsson1 updated
https://github.com/llvm/llvm-project/pull/73511
>From de673830f94a519c94874516f4da24705b736b2e Mon Sep 17 00:00:00 2001
From: Jonas Paulsson <pauls...@linux.ibm.com>
Date: Thu, 23 Nov 2023 17:22:32 +0100
Subject: [PATCH 1/2] IP
---
clang/include/clang/AST/ASTContext.h | 4 +-
clang/include/clang/Basic/TargetInfo.h | 7 +-
clang/include/clang/Driver/Options.td | 4 +
clang/lib/AST/ASTContext.cpp | 15 ++-
clang/lib/Basic/Targets/AArch64.cpp | 5 +-
clang/lib/Basic/Targets/AArch64.h | 2 +-
clang/lib/Basic/Targets/CSKY.cpp | 2 +-
clang/lib/Basic/Targets/CSKY.h | 2 +-
clang/lib/Basic/Targets/NVPTX.cpp | 3 +-
clang/lib/Basic/Targets/SPIR.h | 3 +-
clang/lib/Basic/Targets/SystemZ.cpp | 10 ++
clang/lib/Basic/Targets/SystemZ.h | 9 +-
clang/lib/CodeGen/CodeGenModule.cpp | 7 +-
clang/lib/Driver/ToolChains/Arch/SystemZ.cpp | 8 ++
clang/lib/Sema/SemaOpenMP.cpp | 3 +-
.../test/CodeGen/SystemZ/unaligned-symbols.c | 104 ++++++++++++++++++
llvm/lib/Target/SystemZ/SystemZFeatures.td | 5 +
17 files changed, 171 insertions(+), 22 deletions(-)
create mode 100644 clang/test/CodeGen/SystemZ/unaligned-symbols.c
diff --git a/clang/include/clang/AST/ASTContext.h
b/clang/include/clang/AST/ASTContext.h
index 3e46a5da3fc043f..9e60ca8fb2ea8c6 100644
--- a/clang/include/clang/AST/ASTContext.h
+++ b/clang/include/clang/AST/ASTContext.h
@@ -2406,11 +2406,11 @@ class ASTContext : public RefCountedBase<ASTContext> {
/// Return the alignment in bits that should be given to a
/// global variable with type \p T.
- unsigned getAlignOfGlobalVar(QualType T) const;
+ unsigned getAlignOfGlobalVar(QualType T, bool HasDef) const;
/// Return the alignment in characters that should be given to a
/// global variable with type \p T.
- CharUnits getAlignOfGlobalVarInChars(QualType T) const;
+ CharUnits getAlignOfGlobalVarInChars(QualType T, bool HasDef) const;
/// Return a conservative estimate of the alignment of the specified
/// decl \p D.
diff --git a/clang/include/clang/Basic/TargetInfo.h
b/clang/include/clang/Basic/TargetInfo.h
index aa0f5023104a1a9..ace9e89eda5869b 100644
--- a/clang/include/clang/Basic/TargetInfo.h
+++ b/clang/include/clang/Basic/TargetInfo.h
@@ -704,8 +704,11 @@ class TargetInfo : public TransferrableTargetInfo,
}
/// getMinGlobalAlign - Return the minimum alignment of a global variable,
- /// unless its alignment is explicitly reduced via attributes.
- virtual unsigned getMinGlobalAlign (uint64_t) const {
+ /// unless its alignment is explicitly reduced via attributes. It may be
+ /// that an external symbol needs to be considered unaligned (like
+ /// artificial symbols created from a linker script). If \param HasDef is
+ /// false, this symbol does not have a definition and is external.
+ virtual unsigned getMinGlobalAlign(uint64_t Size, bool HasDef) const {
return MinGlobalAlign;
}
diff --git a/clang/include/clang/Driver/Options.td
b/clang/include/clang/Driver/Options.td
index 1b02087425b7515..dbfb7580db75355 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -4587,6 +4587,10 @@ def munaligned_access : Flag<["-"],
"munaligned-access">, Group<m_Group>,
HelpText<"Allow memory accesses to be unaligned
(AArch32/AArch64/LoongArch/RISC-V only)">;
def mno_unaligned_access : Flag<["-"], "mno-unaligned-access">, Group<m_Group>,
HelpText<"Force all memory accesses to be aligned
(AArch32/AArch64/LoongArch/RISC-V only)">;
+def munaligned_symbols : Flag<["-"], "munaligned-symbols">, Group<m_Group>,
+ HelpText<"Expect external char-aligned symbols to be without ABI alignment
(SystemZ only)">;
+def mno_unaligned_symbols : Flag<["-"], "mno-unaligned-symbols">,
Group<m_Group>,
+ HelpText<"Expect external char-aligned symbols to be without ABI alignment
(SystemZ only)">;
} // let Flags = [TargetSpecific]
def mstrict_align : Flag<["-"], "mstrict-align">, Alias<mno_unaligned_access>,
Flags<[HelpHidden]>, Visibility<[ClangOption, CC1Option]>,
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 0395b3e47ab6f8f..ff15206cbe88621 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -1681,7 +1681,8 @@ CharUnits ASTContext::getDeclAlign(const Decl *D, bool
ForAlignof) const {
if (VD->hasGlobalStorage() && !ForAlignof) {
uint64_t TypeSize =
!BaseT->isIncompleteType() ? getTypeSize(T.getTypePtr()) : 0;
- Align = std::max(Align, getTargetInfo().getMinGlobalAlign(TypeSize));
+ Align = std::max(Align, getTargetInfo().getMinGlobalAlign(
+ TypeSize, VD->hasDefinition()));
}
// Fields can be subject to extra alignment constraints, like if
@@ -2502,17 +2503,19 @@ unsigned
ASTContext::getTargetDefaultAlignForAttributeAligned() const {
}
/// getAlignOfGlobalVar - Return the alignment in bits that should be given
-/// to a global variable of the specified type.
-unsigned ASTContext::getAlignOfGlobalVar(QualType T) const {
+/// to a global variable of the specified type (see comment for
+/// getMinGlobalAlign about HasDef).
+unsigned ASTContext::getAlignOfGlobalVar(QualType T, bool HasDef) const {
uint64_t TypeSize = getTypeSize(T.getTypePtr());
return std::max(getPreferredTypeAlign(T),
- getTargetInfo().getMinGlobalAlign(TypeSize));
+ getTargetInfo().getMinGlobalAlign(TypeSize, HasDef));
}
/// getAlignOfGlobalVarInChars - Return the alignment in characters that
/// should be given to a global variable of the specified type.
-CharUnits ASTContext::getAlignOfGlobalVarInChars(QualType T) const {
- return toCharUnitsFromBits(getAlignOfGlobalVar(T));
+CharUnits ASTContext::getAlignOfGlobalVarInChars(QualType T,
+ bool HasDef) const {
+ return toCharUnitsFromBits(getAlignOfGlobalVar(T, HasDef));
}
CharUnits ASTContext::getOffsetOfBaseWithVBPtr(const CXXRecordDecl *RD) const {
diff --git a/clang/lib/Basic/Targets/AArch64.cpp
b/clang/lib/Basic/Targets/AArch64.cpp
index def16c032c869e5..7690f36c2544990 100644
--- a/clang/lib/Basic/Targets/AArch64.cpp
+++ b/clang/lib/Basic/Targets/AArch64.cpp
@@ -1517,8 +1517,9 @@ MicrosoftARM64TargetInfo::getCallingConvKind(bool
ClangABICompat4) const {
return CCK_MicrosoftWin64;
}
-unsigned MicrosoftARM64TargetInfo::getMinGlobalAlign(uint64_t TypeSize) const {
- unsigned Align = WindowsARM64TargetInfo::getMinGlobalAlign(TypeSize);
+unsigned MicrosoftARM64TargetInfo::getMinGlobalAlign(uint64_t TypeSize,
+ bool HasDef) const {
+ unsigned Align = WindowsARM64TargetInfo::getMinGlobalAlign(TypeSize, HasDef);
// MSVC does size based alignment for arm64 based on alignment section in
// below document, replicate that to keep alignment consistent with object
diff --git a/clang/lib/Basic/Targets/AArch64.h
b/clang/lib/Basic/Targets/AArch64.h
index f0e0782e7abe973..8cfc4281c44456e 100644
--- a/clang/lib/Basic/Targets/AArch64.h
+++ b/clang/lib/Basic/Targets/AArch64.h
@@ -236,7 +236,7 @@ class LLVM_LIBRARY_VISIBILITY MicrosoftARM64TargetInfo
TargetInfo::CallingConvKind
getCallingConvKind(bool ClangABICompat4) const override;
- unsigned getMinGlobalAlign(uint64_t TypeSize) const override;
+ unsigned getMinGlobalAlign(uint64_t TypeSize, bool HasDef) const override;
};
// ARM64 MinGW target
diff --git a/clang/lib/Basic/Targets/CSKY.cpp b/clang/lib/Basic/Targets/CSKY.cpp
index 851f27dbb1e5eed..e173fa1490cd724 100644
--- a/clang/lib/Basic/Targets/CSKY.cpp
+++ b/clang/lib/Basic/Targets/CSKY.cpp
@@ -308,7 +308,7 @@ bool CSKYTargetInfo::validateAsmConstraint(
}
}
-unsigned CSKYTargetInfo::getMinGlobalAlign(uint64_t Size) const {
+unsigned CSKYTargetInfo::getMinGlobalAlign(uint64_t Size, bool HasDef) const {
if (Size >= 32)
return 32;
return 0;
diff --git a/clang/lib/Basic/Targets/CSKY.h b/clang/lib/Basic/Targets/CSKY.h
index 11404e37db368a6..33a7b7ac2b4c345 100644
--- a/clang/lib/Basic/Targets/CSKY.h
+++ b/clang/lib/Basic/Targets/CSKY.h
@@ -71,7 +71,7 @@ class LLVM_LIBRARY_VISIBILITY CSKYTargetInfo : public
TargetInfo {
bool isValidCPUName(StringRef Name) const override;
- unsigned getMinGlobalAlign(uint64_t) const override;
+ unsigned getMinGlobalAlign(uint64_t, bool) const override;
ArrayRef<Builtin::Info> getTargetBuiltins() const override;
diff --git a/clang/lib/Basic/Targets/NVPTX.cpp
b/clang/lib/Basic/Targets/NVPTX.cpp
index c0b5db795e2708a..adf35bc00868d18 100644
--- a/clang/lib/Basic/Targets/NVPTX.cpp
+++ b/clang/lib/Basic/Targets/NVPTX.cpp
@@ -115,7 +115,8 @@ NVPTXTargetInfo::NVPTXTargetInfo(const llvm::Triple &Triple,
LongAlign = HostTarget->getLongAlign();
LongLongWidth = HostTarget->getLongLongWidth();
LongLongAlign = HostTarget->getLongLongAlign();
- MinGlobalAlign = HostTarget->getMinGlobalAlign(/* TypeSize = */ 0);
+ MinGlobalAlign = HostTarget->getMinGlobalAlign(/* TypeSize = */ 0,
+ /* HasDef = */ true);
NewAlign = HostTarget->getNewAlign();
DefaultAlignForAttributeAligned =
HostTarget->getDefaultAlignForAttributeAligned();
diff --git a/clang/lib/Basic/Targets/SPIR.h b/clang/lib/Basic/Targets/SPIR.h
index 9ab2b7c60936392..ff5563d8ecf4495 100644
--- a/clang/lib/Basic/Targets/SPIR.h
+++ b/clang/lib/Basic/Targets/SPIR.h
@@ -124,7 +124,8 @@ class LLVM_LIBRARY_VISIBILITY BaseSPIRTargetInfo : public
TargetInfo {
LongAlign = HostTarget->getLongAlign();
LongLongWidth = HostTarget->getLongLongWidth();
LongLongAlign = HostTarget->getLongLongAlign();
- MinGlobalAlign = HostTarget->getMinGlobalAlign(/* TypeSize = */ 0);
+ MinGlobalAlign = HostTarget->getMinGlobalAlign(/* TypeSize = */ 0,
+ /* HasDef = */ true);
NewAlign = HostTarget->getNewAlign();
DefaultAlignForAttributeAligned =
HostTarget->getDefaultAlignForAttributeAligned();
diff --git a/clang/lib/Basic/Targets/SystemZ.cpp
b/clang/lib/Basic/Targets/SystemZ.cpp
index a9b5ca483861332..76825c6d6a5429b 100644
--- a/clang/lib/Basic/Targets/SystemZ.cpp
+++ b/clang/lib/Basic/Targets/SystemZ.cpp
@@ -138,6 +138,16 @@ bool SystemZTargetInfo::hasFeature(StringRef Feature)
const {
.Default(false);
}
+unsigned SystemZTargetInfo::getMinGlobalAlign(uint64_t Size,
+ bool HasDef) const {
+ // Don't enforce the minimum alignment on an external symbol if
+ // -munaligned-symbols is passed.
+ if (UnalignedSymbols && !HasDef)
+ return 0;
+
+ return MinGlobalAlign;
+}
+
void SystemZTargetInfo::getTargetDefines(const LangOptions &Opts,
MacroBuilder &Builder) const {
Builder.defineMacro("__s390__");
diff --git a/clang/lib/Basic/Targets/SystemZ.h
b/clang/lib/Basic/Targets/SystemZ.h
index e4ec338880f2109..b25360cfbc1c96d 100644
--- a/clang/lib/Basic/Targets/SystemZ.h
+++ b/clang/lib/Basic/Targets/SystemZ.h
@@ -29,11 +29,13 @@ class LLVM_LIBRARY_VISIBILITY SystemZTargetInfo : public
TargetInfo {
bool HasTransactionalExecution;
bool HasVector;
bool SoftFloat;
+ bool UnalignedSymbols;
public:
SystemZTargetInfo(const llvm::Triple &Triple, const TargetOptions &)
: TargetInfo(Triple), CPU("z10"), ISARevision(8),
- HasTransactionalExecution(false), HasVector(false), SoftFloat(false) {
+ HasTransactionalExecution(false), HasVector(false), SoftFloat(false),
+ UnalignedSymbols(false) {
IntMaxType = SignedLong;
Int64Type = SignedLong;
IntWidth = IntAlign = 32;
@@ -64,6 +66,8 @@ class LLVM_LIBRARY_VISIBILITY SystemZTargetInfo : public
TargetInfo {
HasStrictFP = true;
}
+ unsigned getMinGlobalAlign(uint64_t Size, bool HasDef) const override;
+
void getTargetDefines(const LangOptions &Opts,
MacroBuilder &Builder) const override;
@@ -163,6 +167,7 @@ class LLVM_LIBRARY_VISIBILITY SystemZTargetInfo : public
TargetInfo {
HasTransactionalExecution = false;
HasVector = false;
SoftFloat = false;
+ UnalignedSymbols = false;
for (const auto &Feature : Features) {
if (Feature == "+transactional-execution")
HasTransactionalExecution = true;
@@ -170,6 +175,8 @@ class LLVM_LIBRARY_VISIBILITY SystemZTargetInfo : public
TargetInfo {
HasVector = true;
else if (Feature == "+soft-float")
SoftFloat = true;
+ else if (Feature == "+unaligned-symbols")
+ UnalignedSymbols = true;
}
HasVector &= !SoftFloat;
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp
b/clang/lib/CodeGen/CodeGenModule.cpp
index 7ad26ace328ab2e..74bd6a563f4c88b 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -6302,7 +6302,8 @@ GenerateStringLiteral(llvm::Constant *C,
llvm::GlobalValue::LinkageTypes LT,
ConstantAddress
CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S,
StringRef Name) {
- CharUnits Alignment = getContext().getAlignOfGlobalVarInChars(S->getType());
+ CharUnits Alignment =
+ getContext().getAlignOfGlobalVarInChars(S->getType(), /*HasDef=*/true);
llvm::Constant *C = GetConstantArrayFromStringLiteral(S);
llvm::GlobalVariable **Entry = nullptr;
@@ -6365,8 +6366,8 @@
CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) {
ConstantAddress CodeGenModule::GetAddrOfConstantCString(
const std::string &Str, const char *GlobalName) {
StringRef StrWithNull(Str.c_str(), Str.size() + 1);
- CharUnits Alignment =
- getContext().getAlignOfGlobalVarInChars(getContext().CharTy);
+ CharUnits Alignment = getContext().getAlignOfGlobalVarInChars(
+ getContext().CharTy, /*HasDef=*/true);
llvm::Constant *C =
llvm::ConstantDataArray::getString(getLLVMContext(), StrWithNull, false);
diff --git a/clang/lib/Driver/ToolChains/Arch/SystemZ.cpp
b/clang/lib/Driver/ToolChains/Arch/SystemZ.cpp
index 588bc3176d73e38..2213f431eb81145 100644
--- a/clang/lib/Driver/ToolChains/Arch/SystemZ.cpp
+++ b/clang/lib/Driver/ToolChains/Arch/SystemZ.cpp
@@ -71,4 +71,12 @@ void systemz::getSystemZTargetFeatures(const Driver &D,
const ArgList &Args,
systemz::FloatABI FloatABI = systemz::getSystemZFloatABI(D, Args);
if (FloatABI == systemz::FloatABI::Soft)
Features.push_back("+soft-float");
+
+ if (const Arg *A = Args.getLastArg(options::OPT_munaligned_symbols,
+ options::OPT_mno_unaligned_symbols)) {
+ if (A->getOption().matches(options::OPT_munaligned_symbols))
+ Features.push_back("+unaligned-symbols");
+ else
+ Features.push_back("-unaligned-symbols");
+ }
}
diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index 3826994ef2126ce..b167762561019f0 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -2293,9 +2293,10 @@ bool Sema::isOpenMPCapturedByRef(const ValueDecl *D,
unsigned Level,
// and alignment, because the runtime library only deals with uintptr types.
// If it does not fit the uintptr size, we need to pass the data by reference
// instead.
+ bool IsExtern = isa<VarDecl>(D) && !cast<VarDecl>(D)->hasDefinition();
if (!IsByRef && (Ctx.getTypeSizeInChars(Ty) >
Ctx.getTypeSizeInChars(Ctx.getUIntPtrType()) ||
- Ctx.getAlignOfGlobalVarInChars(Ty) >
+ Ctx.getAlignOfGlobalVarInChars(Ty, /*HasDef=*/!IsExtern) >
Ctx.getTypeAlignInChars(Ctx.getUIntPtrType()))) {
IsByRef = true;
}
diff --git a/clang/test/CodeGen/SystemZ/unaligned-symbols.c
b/clang/test/CodeGen/SystemZ/unaligned-symbols.c
new file mode 100644
index 000000000000000..0906d1b67dae999
--- /dev/null
+++ b/clang/test/CodeGen/SystemZ/unaligned-symbols.c
@@ -0,0 +1,104 @@
+// RUN: %clang -target s390x-linux-gnu %s -o - -emit-llvm -S \
+// RUN: | FileCheck %s -check-prefixes=CHECK,ALIGNED
+
+// RUN: %clang -target s390x-linux-gnu %s -o - -emit-llvm -S \
+// RUN: -mno-unaligned-symbols | FileCheck %s -check-prefixes=CHECK,ALIGNED
+
+// RUN: %clang -target s390x-linux-gnu %s -o - -emit-llvm -S \
+// RUN: -munaligned-symbols | FileCheck %s -check-prefixes=CHECK,UNALIGN
+
+// RUN: %clang -cc1 -triple s390x-linux-gnu %s -o - -emit-llvm \
+// RUN: -target-feature +unaligned-symbols | FileCheck %s
-check-prefixes=CHECK,UNALIGN
+
+
+// With -munaligned-symbols, the external and unaligned ("ExtUnal...")
+// variable of each test should be treated as unaligned. For the explicitly
+// aligned ("ExtExplAlign...") variables and those defined in the translation
+// unit ("Aligned..."), the normal ABI alignment of 2 should still be
+// in effect.
+
+// ALIGNED: @ExtUnal = external global i8, align 2
+// UNALIGN: @ExtUnal = external global i8, align 1
+// CHECK: @ExtExplAlign = external global i8, align 2
+// CHECK: @Aligned = {{(dso_local )?}}global i8 0, align 2
+extern unsigned char ExtUnal;
+extern unsigned char ExtExplAlign __attribute__((aligned(2)));
+unsigned char Aligned;
+unsigned char foo0 () {
+ return ExtUnal + ExtExplAlign + Aligned;
+}
+
+// ALIGNED: @ExtUnal_c2Arr = external global [2 x i8], align 2
+// UNALIGN: @ExtUnal_c2Arr = external global [2 x i8], align 1
+// CHECK: @ExtExplAlign_c2Arr = external global [2 x i8], align 2
+// CHECK: @Aligned_c2Arr = {{(dso_local )?}}global [2 x i8] zeroinitializer,
align 2
+extern unsigned char ExtUnal_c2Arr[2];
+extern unsigned char ExtExplAlign_c2Arr[2] __attribute__((aligned(2)));
+unsigned char Aligned_c2Arr[2];
+unsigned char foo1 () {
+ return ExtUnal_c2Arr[0] + ExtExplAlign_c2Arr[0] + Aligned_c2Arr[0];
+}
+
+// ALIGNED: @ExtUnal_s1c = external global %struct.s1c, align 2
+// UNALIGN: @ExtUnal_s1c = external global %struct.s1c, align 1
+// CHECK: @ExtExplAlign_s1c = external global %struct.s1c, align 2
+// CHECK: @Aligned_s1c = {{(dso_local )?}}global %struct.s1c
zeroinitializer, align 2
+struct s1c { char c; };
+extern struct s1c ExtUnal_s1c;
+extern struct s1c ExtExplAlign_s1c __attribute__((aligned(2)));
+struct s1c Aligned_s1c;
+unsigned char foo2 () {
+ return ExtUnal_s1c.c + ExtExplAlign_s1c.c + Aligned_s1c.c;
+}
+
+// ALIGNED: @ExtUnal_s2c = external global %struct.s2c, align 2
+// UNALIGN: @ExtUnal_s2c = external global %struct.s2c, align 1
+// CHECK: @ExtExplAlign_s2c = external global %struct.s2c, align 2
+// CHECK: @Aligned_s2c = {{(dso_local )?}}global %struct.s2c
zeroinitializer, align 2
+struct s2c { char c; char c1;};
+extern struct s2c ExtUnal_s2c;
+extern struct s2c ExtExplAlign_s2c __attribute__((aligned(2)));
+struct s2c Aligned_s2c;
+unsigned char foo3 () {
+ return ExtUnal_s2c.c + ExtExplAlign_s2c.c + Aligned_s2c.c;
+}
+
+// ALIGNED: @ExtUnal_s_c2Arr = external global %struct.s_c2Arr, align 2
+// UNALIGN: @ExtUnal_s_c2Arr = external global %struct.s_c2Arr, align 1
+// CHECK: @ExtExplAlign_s_c2Arr = external global %struct.s_c2Arr, align 2
+// CHECK: @Aligned_s_c2Arr = {{(dso_local )?}}global %struct.s_c2Arr
zeroinitializer, align 2
+struct s_c2Arr { char c[2]; };
+extern struct s_c2Arr ExtUnal_s_c2Arr;
+extern struct s_c2Arr ExtExplAlign_s_c2Arr __attribute__((aligned(2)));
+struct s_c2Arr Aligned_s_c2Arr;
+unsigned char foo4 () {
+ return ExtUnal_s_c2Arr.c[0] + ExtExplAlign_s_c2Arr.c[0] +
Aligned_s_c2Arr.c[0];
+}
+
+// ALIGNED: @ExtUnal_s_packed = external global %struct.s_packed, align 2
+// UNALIGN: @ExtUnal_s_packed = external global %struct.s_packed, align 1
+// CHECK: @ExtExplAlign_s_packed = external global %struct.s_packed, align 2
+// CHECK: @Aligned_s_packed = {{(dso_local )?}}global %struct.s_packed
zeroinitializer, align 2
+struct s_packed {
+ int __attribute__((__packed__)) i;
+ char c;
+};
+extern struct s_packed ExtUnal_s_packed;
+extern struct s_packed ExtExplAlign_s_packed __attribute__((aligned(2)));
+struct s_packed Aligned_s_packed;
+unsigned char foo5 () {
+ return ExtUnal_s_packed.c + ExtExplAlign_s_packed.c + Aligned_s_packed.c;
+}
+
+// ALIGNED: @ExtUnAl_s_nested = external global [2 x %struct.s_nested], align 2
+// UNALIGN: @ExtUnAl_s_nested = external global [2 x %struct.s_nested], align 1
+// CHECK: @ExtExplAlign_s_nested = external global [2 x %struct.s_nested],
align 2
+// CHECK: @Aligned_s_nested = {{(dso_local )?}}global [2 x %struct.s_nested]
zeroinitializer, align 2
+struct s_nested { struct s_c2Arr a[2]; };
+extern struct s_nested ExtUnAl_s_nested[2];
+extern struct s_nested ExtExplAlign_s_nested[2] __attribute__((aligned(2)));
+struct s_nested Aligned_s_nested[2];
+unsigned char foo6 () {
+ return ExtUnAl_s_nested[0].a[0].c[0] + ExtExplAlign_s_nested[0].a[0].c[0] +
+ Aligned_s_nested[0].a[0].c[0];
+}
diff --git a/llvm/lib/Target/SystemZ/SystemZFeatures.td
b/llvm/lib/Target/SystemZ/SystemZFeatures.td
index fdd94206421a418..a1e2a92b40ac232 100644
--- a/llvm/lib/Target/SystemZ/SystemZFeatures.td
+++ b/llvm/lib/Target/SystemZ/SystemZFeatures.td
@@ -37,6 +37,11 @@ def FeatureBackChain : SystemZFeature<
"Store the address of the caller's frame into the callee's stack frame"
>;
+def FeatureUnalignedSymbols : SystemZFeature<
+ "unaligned-symbols", "UnalignedSymbols", (all_of FeatureUnalignedSymbols),
+ "Don't apply the ABI minimum alignment to external symbols."
+>;
+
//===----------------------------------------------------------------------===//
//
// New features added in the Ninth Edition of the z/Architecture
>From c0001b5b3fdcf3fdab76defc21ead8aad1e80746 Mon Sep 17 00:00:00 2001
From: Jonas Paulsson <pauls...@linux.ibm.com>
Date: Tue, 19 Dec 2023 12:56:24 -0600
Subject: [PATCH 2/2] Also handle weak symbols
---
clang/include/clang/AST/ASTContext.h | 4 ++--
clang/include/clang/Basic/TargetInfo.h | 9 ++++-----
clang/lib/AST/ASTContext.cpp | 14 ++++++--------
clang/lib/Basic/Targets/AArch64.cpp | 4 ++--
clang/lib/Basic/Targets/AArch64.h | 3 ++-
clang/lib/Basic/Targets/CSKY.cpp | 3 ++-
clang/lib/Basic/Targets/CSKY.h | 2 +-
clang/lib/Basic/Targets/NVPTX.cpp | 2 +-
clang/lib/Basic/Targets/SPIR.h | 2 +-
clang/lib/Basic/Targets/SystemZ.cpp | 7 ++++---
clang/lib/Basic/Targets/SystemZ.h | 2 +-
clang/lib/CodeGen/CodeGenModule.cpp | 4 ++--
clang/lib/Sema/SemaOpenMP.cpp | 3 +--
clang/test/CodeGen/SystemZ/unaligned-symbols.c | 8 ++++++++
14 files changed, 37 insertions(+), 30 deletions(-)
diff --git a/clang/include/clang/AST/ASTContext.h
b/clang/include/clang/AST/ASTContext.h
index 9e60ca8fb2ea8c6..2c42602bef5a6f3 100644
--- a/clang/include/clang/AST/ASTContext.h
+++ b/clang/include/clang/AST/ASTContext.h
@@ -2406,11 +2406,11 @@ class ASTContext : public RefCountedBase<ASTContext> {
/// Return the alignment in bits that should be given to a
/// global variable with type \p T.
- unsigned getAlignOfGlobalVar(QualType T, bool HasDef) const;
+ unsigned getAlignOfGlobalVar(QualType T, const VarDecl *VD) const;
/// Return the alignment in characters that should be given to a
/// global variable with type \p T.
- CharUnits getAlignOfGlobalVarInChars(QualType T, bool HasDef) const;
+ CharUnits getAlignOfGlobalVarInChars(QualType T, const VarDecl *VD) const;
/// Return a conservative estimate of the alignment of the specified
/// decl \p D.
diff --git a/clang/include/clang/Basic/TargetInfo.h
b/clang/include/clang/Basic/TargetInfo.h
index ace9e89eda5869b..5263c369c1c77bc 100644
--- a/clang/include/clang/Basic/TargetInfo.h
+++ b/clang/include/clang/Basic/TargetInfo.h
@@ -50,6 +50,7 @@ class DiagnosticsEngine;
class LangOptions;
class CodeGenOptions;
class MacroBuilder;
+class VarDecl;
/// Contains information gathered from parsing the contents of TargetAttr.
struct ParsedTargetAttr {
@@ -704,11 +705,9 @@ class TargetInfo : public TransferrableTargetInfo,
}
/// getMinGlobalAlign - Return the minimum alignment of a global variable,
- /// unless its alignment is explicitly reduced via attributes. It may be
- /// that an external symbol needs to be considered unaligned (like
- /// artificial symbols created from a linker script). If \param HasDef is
- /// false, this symbol does not have a definition and is external.
- virtual unsigned getMinGlobalAlign(uint64_t Size, bool HasDef) const {
+ /// unless its alignment is explicitly reduced via attributes. If \param VD
+ /// is non-null, it may be used to examine the specific variable's
attributes.
+ virtual unsigned getMinGlobalAlign(uint64_t Size, const VarDecl *VD) const {
return MinGlobalAlign;
}
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index ff15206cbe88621..c7adbcdc302af40 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -1681,8 +1681,7 @@ CharUnits ASTContext::getDeclAlign(const Decl *D, bool
ForAlignof) const {
if (VD->hasGlobalStorage() && !ForAlignof) {
uint64_t TypeSize =
!BaseT->isIncompleteType() ? getTypeSize(T.getTypePtr()) : 0;
- Align = std::max(Align, getTargetInfo().getMinGlobalAlign(
- TypeSize, VD->hasDefinition()));
+ Align = std::max(Align, getTargetInfo().getMinGlobalAlign(TypeSize,
VD));
}
// Fields can be subject to extra alignment constraints, like if
@@ -2503,19 +2502,18 @@ unsigned
ASTContext::getTargetDefaultAlignForAttributeAligned() const {
}
/// getAlignOfGlobalVar - Return the alignment in bits that should be given
-/// to a global variable of the specified type (see comment for
-/// getMinGlobalAlign about HasDef).
-unsigned ASTContext::getAlignOfGlobalVar(QualType T, bool HasDef) const {
+/// to a global variable of the specified type.
+unsigned ASTContext::getAlignOfGlobalVar(QualType T, const VarDecl *VD) const {
uint64_t TypeSize = getTypeSize(T.getTypePtr());
return std::max(getPreferredTypeAlign(T),
- getTargetInfo().getMinGlobalAlign(TypeSize, HasDef));
+ getTargetInfo().getMinGlobalAlign(TypeSize, VD));
}
/// getAlignOfGlobalVarInChars - Return the alignment in characters that
/// should be given to a global variable of the specified type.
CharUnits ASTContext::getAlignOfGlobalVarInChars(QualType T,
- bool HasDef) const {
- return toCharUnitsFromBits(getAlignOfGlobalVar(T, HasDef));
+ const VarDecl *VD) const {
+ return toCharUnitsFromBits(getAlignOfGlobalVar(T, VD));
}
CharUnits ASTContext::getOffsetOfBaseWithVBPtr(const CXXRecordDecl *RD) const {
diff --git a/clang/lib/Basic/Targets/AArch64.cpp
b/clang/lib/Basic/Targets/AArch64.cpp
index 7690f36c2544990..465c22535350521 100644
--- a/clang/lib/Basic/Targets/AArch64.cpp
+++ b/clang/lib/Basic/Targets/AArch64.cpp
@@ -1518,8 +1518,8 @@ MicrosoftARM64TargetInfo::getCallingConvKind(bool
ClangABICompat4) const {
}
unsigned MicrosoftARM64TargetInfo::getMinGlobalAlign(uint64_t TypeSize,
- bool HasDef) const {
- unsigned Align = WindowsARM64TargetInfo::getMinGlobalAlign(TypeSize, HasDef);
+ const VarDecl *VD) const {
+ unsigned Align = WindowsARM64TargetInfo::getMinGlobalAlign(TypeSize, VD);
// MSVC does size based alignment for arm64 based on alignment section in
// below document, replicate that to keep alignment consistent with object
diff --git a/clang/lib/Basic/Targets/AArch64.h
b/clang/lib/Basic/Targets/AArch64.h
index 8cfc4281c44456e..7ef01fd44a311a0 100644
--- a/clang/lib/Basic/Targets/AArch64.h
+++ b/clang/lib/Basic/Targets/AArch64.h
@@ -236,7 +236,8 @@ class LLVM_LIBRARY_VISIBILITY MicrosoftARM64TargetInfo
TargetInfo::CallingConvKind
getCallingConvKind(bool ClangABICompat4) const override;
- unsigned getMinGlobalAlign(uint64_t TypeSize, bool HasDef) const override;
+ unsigned getMinGlobalAlign(uint64_t TypeSize,
+ const VarDecl *VD) const override;
};
// ARM64 MinGW target
diff --git a/clang/lib/Basic/Targets/CSKY.cpp b/clang/lib/Basic/Targets/CSKY.cpp
index e173fa1490cd724..e0c6d72a3644334 100644
--- a/clang/lib/Basic/Targets/CSKY.cpp
+++ b/clang/lib/Basic/Targets/CSKY.cpp
@@ -308,7 +308,8 @@ bool CSKYTargetInfo::validateAsmConstraint(
}
}
-unsigned CSKYTargetInfo::getMinGlobalAlign(uint64_t Size, bool HasDef) const {
+unsigned CSKYTargetInfo::getMinGlobalAlign(uint64_t Size,
+ const VarDecl *VD) const {
if (Size >= 32)
return 32;
return 0;
diff --git a/clang/lib/Basic/Targets/CSKY.h b/clang/lib/Basic/Targets/CSKY.h
index 33a7b7ac2b4c345..ad46eae6fc9de20 100644
--- a/clang/lib/Basic/Targets/CSKY.h
+++ b/clang/lib/Basic/Targets/CSKY.h
@@ -71,7 +71,7 @@ class LLVM_LIBRARY_VISIBILITY CSKYTargetInfo : public
TargetInfo {
bool isValidCPUName(StringRef Name) const override;
- unsigned getMinGlobalAlign(uint64_t, bool) const override;
+ unsigned getMinGlobalAlign(uint64_t, const VarDecl *) const override;
ArrayRef<Builtin::Info> getTargetBuiltins() const override;
diff --git a/clang/lib/Basic/Targets/NVPTX.cpp
b/clang/lib/Basic/Targets/NVPTX.cpp
index adf35bc00868d18..0806719ef3722e4 100644
--- a/clang/lib/Basic/Targets/NVPTX.cpp
+++ b/clang/lib/Basic/Targets/NVPTX.cpp
@@ -116,7 +116,7 @@ NVPTXTargetInfo::NVPTXTargetInfo(const llvm::Triple &Triple,
LongLongWidth = HostTarget->getLongLongWidth();
LongLongAlign = HostTarget->getLongLongAlign();
MinGlobalAlign = HostTarget->getMinGlobalAlign(/* TypeSize = */ 0,
- /* HasDef = */ true);
+ /* VD = */ nullptr);
NewAlign = HostTarget->getNewAlign();
DefaultAlignForAttributeAligned =
HostTarget->getDefaultAlignForAttributeAligned();
diff --git a/clang/lib/Basic/Targets/SPIR.h b/clang/lib/Basic/Targets/SPIR.h
index ff5563d8ecf4495..5745ec860e5e7e1 100644
--- a/clang/lib/Basic/Targets/SPIR.h
+++ b/clang/lib/Basic/Targets/SPIR.h
@@ -125,7 +125,7 @@ class LLVM_LIBRARY_VISIBILITY BaseSPIRTargetInfo : public
TargetInfo {
LongLongWidth = HostTarget->getLongLongWidth();
LongLongAlign = HostTarget->getLongLongAlign();
MinGlobalAlign = HostTarget->getMinGlobalAlign(/* TypeSize = */ 0,
- /* HasDef = */ true);
+ /* VD = */ nullptr);
NewAlign = HostTarget->getNewAlign();
DefaultAlignForAttributeAligned =
HostTarget->getDefaultAlignForAttributeAligned();
diff --git a/clang/lib/Basic/Targets/SystemZ.cpp
b/clang/lib/Basic/Targets/SystemZ.cpp
index 76825c6d6a5429b..578e026661c5417 100644
--- a/clang/lib/Basic/Targets/SystemZ.cpp
+++ b/clang/lib/Basic/Targets/SystemZ.cpp
@@ -11,6 +11,7 @@
//===----------------------------------------------------------------------===//
#include "SystemZ.h"
+#include "clang/AST/Decl.h"
#include "clang/Basic/Builtins.h"
#include "clang/Basic/LangOptions.h"
#include "clang/Basic/MacroBuilder.h"
@@ -139,10 +140,10 @@ bool SystemZTargetInfo::hasFeature(StringRef Feature)
const {
}
unsigned SystemZTargetInfo::getMinGlobalAlign(uint64_t Size,
- bool HasDef) const {
- // Don't enforce the minimum alignment on an external symbol if
+ const VarDecl *VD) const {
+ // Don't enforce the minimum alignment on an external or weak symbol if
// -munaligned-symbols is passed.
- if (UnalignedSymbols && !HasDef)
+ if (UnalignedSymbols && VD && (!VD->hasDefinition() || VD->isWeak()))
return 0;
return MinGlobalAlign;
diff --git a/clang/lib/Basic/Targets/SystemZ.h
b/clang/lib/Basic/Targets/SystemZ.h
index b25360cfbc1c96d..f701a2370c074e5 100644
--- a/clang/lib/Basic/Targets/SystemZ.h
+++ b/clang/lib/Basic/Targets/SystemZ.h
@@ -66,7 +66,7 @@ class LLVM_LIBRARY_VISIBILITY SystemZTargetInfo : public
TargetInfo {
HasStrictFP = true;
}
- unsigned getMinGlobalAlign(uint64_t Size, bool HasDef) const override;
+ unsigned getMinGlobalAlign(uint64_t Size, const VarDecl *VD) const override;
void getTargetDefines(const LangOptions &Opts,
MacroBuilder &Builder) const override;
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp
b/clang/lib/CodeGen/CodeGenModule.cpp
index 74bd6a563f4c88b..7605bae497bea03 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -6303,7 +6303,7 @@ ConstantAddress
CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S,
StringRef Name) {
CharUnits Alignment =
- getContext().getAlignOfGlobalVarInChars(S->getType(), /*HasDef=*/true);
+ getContext().getAlignOfGlobalVarInChars(S->getType(), /*VD=*/nullptr);
llvm::Constant *C = GetConstantArrayFromStringLiteral(S);
llvm::GlobalVariable **Entry = nullptr;
@@ -6367,7 +6367,7 @@ ConstantAddress CodeGenModule::GetAddrOfConstantCString(
const std::string &Str, const char *GlobalName) {
StringRef StrWithNull(Str.c_str(), Str.size() + 1);
CharUnits Alignment = getContext().getAlignOfGlobalVarInChars(
- getContext().CharTy, /*HasDef=*/true);
+ getContext().CharTy, /*VD=*/nullptr);
llvm::Constant *C =
llvm::ConstantDataArray::getString(getLLVMContext(), StrWithNull, false);
diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index b167762561019f0..40fa7b74a178a2d 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -2293,10 +2293,9 @@ bool Sema::isOpenMPCapturedByRef(const ValueDecl *D,
unsigned Level,
// and alignment, because the runtime library only deals with uintptr types.
// If it does not fit the uintptr size, we need to pass the data by reference
// instead.
- bool IsExtern = isa<VarDecl>(D) && !cast<VarDecl>(D)->hasDefinition();
if (!IsByRef && (Ctx.getTypeSizeInChars(Ty) >
Ctx.getTypeSizeInChars(Ctx.getUIntPtrType()) ||
- Ctx.getAlignOfGlobalVarInChars(Ty, /*HasDef=*/!IsExtern) >
+ Ctx.getAlignOfGlobalVarInChars(Ty, dyn_cast<VarDecl>(D)) >
Ctx.getTypeAlignInChars(Ctx.getUIntPtrType()))) {
IsByRef = true;
}
diff --git a/clang/test/CodeGen/SystemZ/unaligned-symbols.c
b/clang/test/CodeGen/SystemZ/unaligned-symbols.c
index 0906d1b67dae999..4ed2a1b739b223d 100644
--- a/clang/test/CodeGen/SystemZ/unaligned-symbols.c
+++ b/clang/test/CodeGen/SystemZ/unaligned-symbols.c
@@ -102,3 +102,11 @@ unsigned char foo6 () {
return ExtUnAl_s_nested[0].a[0].c[0] + ExtExplAlign_s_nested[0].a[0].c[0] +
Aligned_s_nested[0].a[0].c[0];
}
+
+// A weak symbol could be replaced with an unaligned one at link time.
+// CHECK-LABEL: foo7
+// CHECK-NOT: larl {{.*}}Weaksym
+unsigned char __attribute__((weak)) Weaksym = 0;
+unsigned char foo7 () {
+ return Weaksym;
+}
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