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[clang][X86] Support __attribute__((model("small"/"large"))) #124834

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Merged
merged 13 commits into from
Feb 15, 2025
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Merged

[clang][X86] Support __attribute__((model("small"/"large"))) #124834

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7c40169
[clang][X86] Support __attribute__((model("small"/"large")))
aeubanks Jan 28, 2025
8aa6b3f
address comments
aeubanks Jan 29, 2025
2fdf2ee
add nvptx RUN line to test, refactor test
aeubanks Jan 29, 2025
1a32c31
add more flags to RUN line
aeubanks Jan 29, 2025
7ce06bd
allow and ignore attribute on nvptx compiles
aeubanks Feb 3, 2025
526e8c3
Merge remote-tracking branch 'upstream/main' into model
aeubanks Feb 3, 2025
6779705
ignore amdgpu/spirv
aeubanks Feb 4, 2025
2263db1
update AttrDocs.td
aeubanks Feb 5, 2025
bf8f7d4
more descriptive docs (at least for x86-64)
aeubanks Feb 5, 2025
d314c8e
warn if host triple doesn't support attribute
aeubanks Feb 12, 2025
1729029
llvm::Triple&
aeubanks Feb 12, 2025
c664880
one more &
aeubanks Feb 12, 2025
f3ecb7b
Merge remote-tracking branch 'upstream/main' into model
aeubanks Feb 14, 2025
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5 changes: 5 additions & 0 deletions clang/docs/ReleaseNotes.rst
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Original file line number Diff line number Diff line change
Expand Up @@ -657,6 +657,11 @@ Attribute Changes in Clang

- Clang now disallows the use of attributes after the namespace name. (#GH121407)

- Clang now allows ``__attribute__((model("small")))`` and
``__attribute__((model("large")))`` on non-TLS globals in x86-64 compilations.
This forces the global to be considered small or large in regards to the
x86-64 code model, regardless of the code model specified for the compilation.

Improvements to Clang's diagnostics
-----------------------------------

Expand Down
13 changes: 9 additions & 4 deletions clang/include/clang/Basic/Attr.td
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Expand Up @@ -462,6 +462,7 @@ def TargetMSP430 : TargetArch<["msp430"]>;
def TargetM68k : TargetArch<["m68k"]>;
def TargetRISCV : TargetArch<["riscv32", "riscv64"]>;
def TargetX86 : TargetArch<["x86"]>;
def TargetX86_64 : TargetArch<["x86_64"]>;
def TargetAnyX86 : TargetArch<["x86", "x86_64"]>;
def TargetWebAssembly : TargetArch<["wasm32", "wasm64"]>;
def TargetNVPTX : TargetArch<["nvptx", "nvptx64"]>;
Expand Down Expand Up @@ -3117,11 +3118,15 @@ def PragmaClangTextSection : InheritableAttr {
let Documentation = [InternalOnly];
}

def CodeModel : InheritableAttr, TargetSpecificAttr<TargetLoongArch> {
def CodeModel : InheritableAttr,
TargetSpecificAttr<TargetArch<!listconcat(
TargetLoongArch.Arches, TargetX86_64.Arches)>> {
let Spellings = [GCC<"model">];
let Args = [EnumArgument<"Model", "llvm::CodeModel::Model", /*is_string=*/1,
["normal", "medium", "extreme"], ["Small", "Medium", "Large"],
/*opt=*/0, /*fake=*/0, /*isExternalType=*/1, /*isCovered=*/0>];
let Args = [EnumArgument<
"Model", "llvm::CodeModel::Model",
/*is_string=*/1, ["small", "normal", "medium", "large", "extreme"],
["Small", "Small", "Medium", "Large", "Large"],
/*opt=*/0, /*fake=*/0, /*isExternalType=*/1, /*isCovered=*/0>];
let Subjects = SubjectList<[NonTLSGlobalVar], ErrorDiag>;
let Documentation = [CodeModelDocs];
}
Expand Down
11 changes: 10 additions & 1 deletion clang/lib/Sema/SemaDeclAttr.cpp
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Expand Up @@ -64,6 +64,7 @@
#include "llvm/IR/DerivedTypes.h"
#include "llvm/MC/MCSectionMachO.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/TargetParser/Triple.h"
Expand Down Expand Up @@ -2949,6 +2950,13 @@ static void handleSectionAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
}
}

static bool isValidCodeModelAttr(Sema &S, StringRef Str) {
bool IsX8664Target =
S.Context.getTargetInfo().getTriple().getArch() == llvm::Triple::x86_64;
bool IsX8664Spelling = Str == "small" || Str == "large";
return IsX8664Target == IsX8664Spelling;
}

static void handleCodeModelAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
StringRef Str;
SourceLocation LiteralLoc;
Expand All @@ -2957,7 +2965,8 @@ static void handleCodeModelAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
return;

llvm::CodeModel::Model CM;
if (!CodeModelAttr::ConvertStrToModel(Str, CM)) {
if (!CodeModelAttr::ConvertStrToModel(Str, CM) ||
!isValidCodeModelAttr(S, Str)) {
S.Diag(LiteralLoc, diag::err_attr_codemodel_arg) << Str;
return;
}
Expand Down
27 changes: 27 additions & 0 deletions clang/test/CodeGen/X86/codemodel.cpp
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@@ -0,0 +1,27 @@
// RUN: %clang_cc1 -emit-llvm -triple x86_64-unknown-unknown %s -o - | FileCheck %s

// CHECK: @_ZL2v1 ={{.*}} global i32 0, code_model "small"
static int v1 __attribute__((model("small")));

void use1() {
v1 = 1;
}

// CHECK: @v2 ={{.*}} global float 0.000000e+00, code_model "large"
float v2 __attribute__((model("large")));

// CHECK: @_ZL2v3IiE ={{.*}} global i32 0, code_model "small"
template <typename T>
static T v3 __attribute__((model("small")));

void use2() {
v3<int> = 1;
}
struct S {
double d;
};

typedef void (*F)();

// CHECK: @v4 ={{.*}} global ptr null, code_model "large"
F v4 __attribute__((model("large")));
22 changes: 10 additions & 12 deletions clang/test/Sema/attr-model.cpp
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Expand Up @@ -5,7 +5,7 @@
// RUN: %clang_cc1 -triple riscv64 -verify=expected,riscv64 -fsyntax-only %s
// RUN: %clang_cc1 -triple x86_64 -verify=expected,x86_64 -fsyntax-only %s

#if defined(__loongarch__) && !__has_attribute(model)
#if (defined(__loongarch__) || defined(__x86_64__)) && !__has_attribute(model)
#error "Should support model attribute"
#endif

Expand All @@ -14,51 +14,49 @@ int a __attribute((model("tiny"))); // aarch64-warning {{unknown attribute 'm
// mips64-warning {{unknown attribute 'model' ignored}} \
// powerpc64-warning {{unknown attribute 'model' ignored}} \
// riscv64-warning {{unknown attribute 'model' ignored}} \
// x86_64-warning {{unknown attribute 'model' ignored}}
// x86_64-error {{code model 'tiny' is not supported on this target}}
int b __attribute((model("small"))); // aarch64-warning {{unknown attribute 'model' ignored}} \
// loongarch64-error {{code model 'small' is not supported on this target}} \
// mips64-warning {{unknown attribute 'model' ignored}} \
// powerpc64-warning {{unknown attribute 'model' ignored}} \
// riscv64-warning {{unknown attribute 'model' ignored}} \
// x86_64-warning {{unknown attribute 'model' ignored}}
// riscv64-warning {{unknown attribute 'model' ignored}}
int c __attribute((model("normal"))); // aarch64-warning {{unknown attribute 'model' ignored}} \
// mips64-warning {{unknown attribute 'model' ignored}} \
// powerpc64-warning {{unknown attribute 'model' ignored}} \
// riscv64-warning {{unknown attribute 'model' ignored}} \
// x86_64-warning {{unknown attribute 'model' ignored}}
// x86_64-error {{code model 'normal' is not supported on this target}}
int d __attribute((model("kernel"))); // aarch64-warning {{unknown attribute 'model' ignored}} \
// loongarch64-error {{code model 'kernel' is not supported on this target}} \
// mips64-warning {{unknown attribute 'model' ignored}} \
// powerpc64-warning {{unknown attribute 'model' ignored}} \
// riscv64-warning {{unknown attribute 'model' ignored}} \
// x86_64-warning {{unknown attribute 'model' ignored}}
// x86_64-error {{code model 'kernel' is not supported on this target}}
int e __attribute((model("medium"))); // aarch64-warning {{unknown attribute 'model' ignored}} \
// mips64-warning {{unknown attribute 'model' ignored}} \
// powerpc64-warning {{unknown attribute 'model' ignored}} \
// riscv64-warning {{unknown attribute 'model' ignored}} \
// x86_64-warning {{unknown attribute 'model' ignored}}
// x86_64-error {{code model 'medium' is not supported on this target}}
int f __attribute((model("large"))); // aarch64-warning {{unknown attribute 'model' ignored}} \
// loongarch64-error {{code model 'large' is not supported on this target}} \
// mips64-warning {{unknown attribute 'model' ignored}} \
// powerpc64-warning {{unknown attribute 'model' ignored}} \
// riscv64-warning {{unknown attribute 'model' ignored}} \
// x86_64-warning {{unknown attribute 'model' ignored}}
// riscv64-warning {{unknown attribute 'model' ignored}}
int g __attribute((model("extreme"))); // aarch64-warning {{unknown attribute 'model' ignored}} \
// mips64-warning {{unknown attribute 'model' ignored}} \
// powerpc64-warning {{unknown attribute 'model' ignored}} \
// riscv64-warning {{unknown attribute 'model' ignored}} \
// x86_64-warning {{unknown attribute 'model' ignored}}
// x86_64-error {{code model 'extreme' is not supported on this target}}

void __attribute((model("extreme"))) h() {} // aarch64-warning {{unknown attribute 'model' ignored}} \
// loongarch64-error {{'model' attribute only applies to non-TLS global variables}} \
// mips64-warning {{unknown attribute 'model' ignored}} \
// powerpc64-warning {{unknown attribute 'model' ignored}} \
// riscv64-warning {{unknown attribute 'model' ignored}} \
// x86_64-warning {{unknown attribute 'model' ignored}}
// x86_64-error {{'model' attribute only applies to non-TLS global variables}}

thread_local int i __attribute((model("extreme"))); // aarch64-warning {{unknown attribute 'model' ignored}} \
// loongarch64-error {{'model' attribute only applies to non-TLS global variables}} \
// mips64-warning {{unknown attribute 'model' ignored}} \
// powerpc64-warning {{unknown attribute 'model' ignored}} \
// riscv64-warning {{unknown attribute 'model' ignored}} \
// x86_64-warning {{unknown attribute 'model' ignored}}
// x86_64-error {{'model' attribute only applies to non-TLS global variables}}