[clang] [C++17] Support __GCC_[CON|DE]STRUCTIVE_SIZE (PR #89446)
Aaron Ballman via cfe-commits
cfe-commits at lists.llvm.org
Fri Apr 19 12:59:26 PDT 2024
https://github.com/AaronBallman created https://github.com/llvm/llvm-project/pull/89446
These macros are used by STL implementations to support implementation of std::hardware_destructive_interference_size and std::hardware_constructive_interference_size
Fixes #60174
>From 9d394964d3d04c9d7ffd753751f2aaa3a96c9480 Mon Sep 17 00:00:00 2001
From: Aaron Ballman <aaron at aaronballman.com>
Date: Fri, 19 Apr 2024 15:56:54 -0400
Subject: [PATCH] [C++17] Support __GCC_[CON|DE]STRUCTIVE_SIZE
These macros are used by STL implementations to support implementation
of std::hardware_destructive_interference_size and
std::hardware_constructive_interference_size
Fixes #60174
---
clang/docs/ReleaseNotes.rst | 13 +++++
clang/include/clang/Basic/TargetInfo.h | 5 ++
clang/lib/Frontend/InitPreprocessor.cpp | 7 +++
clang/test/Preprocessor/init-aarch64.c | 12 +++--
clang/test/Preprocessor/init.c | 49 +++++++++++--------
.../test/Preprocessor/predefined-win-macros.c | 6 ++-
6 files changed, 65 insertions(+), 27 deletions(-)
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index aea8fda35bb29c..7414856fd6a03e 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -89,6 +89,19 @@ sections with improvements to Clang's support for those languages.
C++ Language Changes
--------------------
+C++17 Feature Support
+^^^^^^^^^^^^^^^^^^^^^
+- Clang now exposes ``__GCC_DESTRUCTIVE_SIZE`` and ``__GCC_CONSTRUCTIVE_SIZE``
+ predefined macros to support standard library implementations of
+ ``std::hardware_destructive_interference_size`` and
+ ``std::hardware_constructive_interference_size``, respectively. These macros
+ are predefined in all C and C++ language modes. These macros can be
+ overridden on the command line with ``-D``, if desired. The values the macros
+ expand to are not stable between releases of Clang and do not need to match
+ the values produced by GCC, so these macros should not be used from header
+ files because they may not be stable across multiple TUs (the values may vary
+ based on compiler version as well as CPU tuning). #GH60174
+
C++20 Feature Support
^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/include/clang/Basic/TargetInfo.h b/clang/include/clang/Basic/TargetInfo.h
index e1ef7454f01669..a7b112a41f1b99 100644
--- a/clang/include/clang/Basic/TargetInfo.h
+++ b/clang/include/clang/Basic/TargetInfo.h
@@ -1792,6 +1792,11 @@ class TargetInfo : public TransferrableTargetInfo,
/// Whether to support HIP image/texture API's.
virtual bool hasHIPImageSupport() const { return true; }
+ /// The minimum offset between two objects to avoid false sharing.
+ virtual unsigned hardwareDestructiveInterferenceSize() const { return 64; }
+ // The maximum size of contiguous memory to promote true sharing.
+ virtual unsigned hardwareConstructiveInterferenceSize() const { return 64; }
+
protected:
/// Copy type and layout related info.
void copyAuxTarget(const TargetInfo *Aux);
diff --git a/clang/lib/Frontend/InitPreprocessor.cpp b/clang/lib/Frontend/InitPreprocessor.cpp
index 4f44c3b7b89d4d..b88cd86e09fa1e 100644
--- a/clang/lib/Frontend/InitPreprocessor.cpp
+++ b/clang/lib/Frontend/InitPreprocessor.cpp
@@ -1309,6 +1309,13 @@ static void InitializePredefinedMacros(const TargetInfo &TI,
Builder.defineMacro("__GCC_ATOMIC_TEST_AND_SET_TRUEVAL", "1");
}
+ // GCC defines these macros in both C and C++ modes despite them being needed
+ // mostly for STL implementations in C++.
+ Builder.defineMacro("__GCC_DESTRUCTIVE_SIZE",
+ Twine(TI.hardwareDestructiveInterferenceSize()));
+ Builder.defineMacro("__GCC_CONSTRUCTIVE_SIZE",
+ Twine(TI.hardwareConstructiveInterferenceSize()));
+
auto addLockFreeMacros = [&](const llvm::Twine &Prefix) {
// Used by libc++ and libstdc++ to implement ATOMIC_<foo>_LOCK_FREE.
#define DEFINE_LOCK_FREE_MACRO(TYPE, Type) \
diff --git a/clang/test/Preprocessor/init-aarch64.c b/clang/test/Preprocessor/init-aarch64.c
index cf96870b27acb3..f0845985c9efc3 100644
--- a/clang/test/Preprocessor/init-aarch64.c
+++ b/clang/test/Preprocessor/init-aarch64.c
@@ -119,6 +119,8 @@
// AARCH64-NEXT: #define __FP_FAST_FMA 1
// AARCH64-NEXT: #define __FP_FAST_FMAF 1
// AARCH64-NEXT: #define __GCC_ASM_FLAG_OUTPUTS__ 1
+// AARCH64-NEXT: #define __GCC_CONSTRUCTIVE_SIZE {{.+}}
+// AARCH64-NEXT: #define __GCC_DESTRUCTIVE_SIZE {{.+}}
// AARCH64-NEXT: #define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_1 1
// AARCH64-NEXT: #define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16 1
// AARCH64-NEXT: #define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_2 1
@@ -220,11 +222,11 @@
// AARCH64-NEXT: #define __LONG_MAX__ 9223372036854775807L
// AARCH64-NEXT: #define __LONG_WIDTH__ 64
// AARCH64-NEXT: #define __LP64__ 1
-// AARCH64-NEXT: #define __MEMORY_SCOPE_DEVICE 1
-// AARCH64-NEXT: #define __MEMORY_SCOPE_SINGLE 4
-// AARCH64-NEXT: #define __MEMORY_SCOPE_SYSTEM 0
-// AARCH64-NEXT: #define __MEMORY_SCOPE_WRKGRP 2
-// AARCH64-NEXT: #define __MEMORY_SCOPE_WVFRNT 3
+// AARCH64-NEXT: #define __MEMORY_SCOPE_DEVICE 1
+// AARCH64-NEXT: #define __MEMORY_SCOPE_SINGLE 4
+// AARCH64-NEXT: #define __MEMORY_SCOPE_SYSTEM 0
+// AARCH64-NEXT: #define __MEMORY_SCOPE_WRKGRP 2
+// AARCH64-NEXT: #define __MEMORY_SCOPE_WVFRNT 3
// AARCH64-NEXT: #define __NO_INLINE__ 1
// AARCH64-NEXT: #define __NO_MATH_ERRNO__ 1
// AARCH64-NEXT: #define __OBJC_BOOL_IS_BOOL 0
diff --git a/clang/test/Preprocessor/init.c b/clang/test/Preprocessor/init.c
index c4a55efca6f712..2641fee940231f 100644
--- a/clang/test/Preprocessor/init.c
+++ b/clang/test/Preprocessor/init.c
@@ -1,3 +1,10 @@
+// RUN: %clang_cc1 -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix INTERFERENCE %s
+//
+// We purposefully do not test the values produced, only that the macros are
+// predefined to some value.
+// INTERFERENCE:#define __GCC_CONSTRUCTIVE_SIZE {{.+}}
+// INTERFERENCE:#define __GCC_DESTRUCTIVE_SIZE {{.+}}
+
// RUN: %clang_cc1 -E -dM -x assembler-with-cpp < /dev/null | FileCheck -match-full-lines -check-prefix ASM %s
//
// ASM:#define __ASSEMBLER__ 1
@@ -1697,6 +1704,8 @@
// WEBASSEMBLY-NEXT:#define __GCC_ATOMIC_SHORT_LOCK_FREE 2
// WEBASSEMBLY-NEXT:#define __GCC_ATOMIC_TEST_AND_SET_TRUEVAL 1
// WEBASSEMBLY-NEXT:#define __GCC_ATOMIC_WCHAR_T_LOCK_FREE 2
+// WEBASSEMBLY-NEXT:#define __GCC_CONSTRUCTIVE_SIZE {{.+}}
+// WEBASSEMBLY-NEXT:#define __GCC_DESTRUCTIVE_SIZE {{.+}}
// WEBASSEMBLY-NEXT:#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_1 1
// WEBASSEMBLY-NEXT:#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_2 1
// WEBASSEMBLY-NEXT:#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 1
@@ -1806,11 +1815,11 @@
// WEBASSEMBLY64-NEXT:#define __LONG_MAX__ 9223372036854775807L
// WEBASSEMBLY64-NEXT:#define __LONG_WIDTH__ 64
// WEBASSEMBLY64-NEXT:#define __LP64__ 1
-// WEBASSEMBLY-NEXT:#define __MEMORY_SCOPE_DEVICE 1
-// WEBASSEMBLY-NEXT:#define __MEMORY_SCOPE_SINGLE 4
-// WEBASSEMBLY-NEXT:#define __MEMORY_SCOPE_SYSTEM 0
-// WEBASSEMBLY-NEXT:#define __MEMORY_SCOPE_WRKGRP 2
-// WEBASSEMBLY-NEXT:#define __MEMORY_SCOPE_WVFRNT 3
+// WEBASSEMBLY-NEXT:#define __MEMORY_SCOPE_DEVICE 1
+// WEBASSEMBLY-NEXT:#define __MEMORY_SCOPE_SINGLE 4
+// WEBASSEMBLY-NEXT:#define __MEMORY_SCOPE_SYSTEM 0
+// WEBASSEMBLY-NEXT:#define __MEMORY_SCOPE_WRKGRP 2
+// WEBASSEMBLY-NEXT:#define __MEMORY_SCOPE_WVFRNT 3
// WEBASSEMBLY-NEXT:#define __NO_INLINE__ 1
// WEBASSEMBLY-NEXT:#define __NO_MATH_ERRNO__ 1
// WEBASSEMBLY-NEXT:#define __OBJC_BOOL_IS_BOOL 0
@@ -2126,11 +2135,11 @@
// AVR:#define __LDBL_MIN__ 1.17549435e-38L
// AVR:#define __LONG_LONG_MAX__ 9223372036854775807LL
// AVR:#define __LONG_MAX__ 2147483647L
-// AVR:#define __MEMORY_SCOPE_DEVICE 1
-// AVR:#define __MEMORY_SCOPE_SINGLE 4
-// AVR:#define __MEMORY_SCOPE_SYSTEM 0
-// AVR:#define __MEMORY_SCOPE_WRKGRP 2
-// AVR:#define __MEMORY_SCOPE_WVFRNT 3
+// AVR:#define __MEMORY_SCOPE_DEVICE 1
+// AVR:#define __MEMORY_SCOPE_SINGLE 4
+// AVR:#define __MEMORY_SCOPE_SYSTEM 0
+// AVR:#define __MEMORY_SCOPE_WRKGRP 2
+// AVR:#define __MEMORY_SCOPE_WVFRNT 3
// AVR:#define __NO_INLINE__ 1
// AVR:#define __ORDER_BIG_ENDIAN__ 4321
// AVR:#define __ORDER_LITTLE_ENDIAN__ 1234
@@ -2422,11 +2431,11 @@
// RISCV32: #define __LITTLE_ENDIAN__ 1
// RISCV32: #define __LONG_LONG_MAX__ 9223372036854775807LL
// RISCV32: #define __LONG_MAX__ 2147483647L
-// RISCV32: #define __MEMORY_SCOPE_DEVICE 1
-// RISCV32: #define __MEMORY_SCOPE_SINGLE 4
-// RISCV32: #define __MEMORY_SCOPE_SYSTEM 0
-// RISCV32: #define __MEMORY_SCOPE_WRKGRP 2
-// RISCV32: #define __MEMORY_SCOPE_WVFRNT 3
+// RISCV32: #define __MEMORY_SCOPE_DEVICE 1
+// RISCV32: #define __MEMORY_SCOPE_SINGLE 4
+// RISCV32: #define __MEMORY_SCOPE_SYSTEM 0
+// RISCV32: #define __MEMORY_SCOPE_WRKGRP 2
+// RISCV32: #define __MEMORY_SCOPE_WVFRNT 3
// RISCV32: #define __NO_INLINE__ 1
// RISCV32: #define __POINTER_WIDTH__ 32
// RISCV32: #define __PRAGMA_REDEFINE_EXTNAME 1
@@ -2634,11 +2643,11 @@
// RISCV64: #define __LONG_LONG_MAX__ 9223372036854775807LL
// RISCV64: #define __LONG_MAX__ 9223372036854775807L
// RISCV64: #define __LP64__ 1
-// RISCV64: #define __MEMORY_SCOPE_DEVICE 1
-// RISCV64: #define __MEMORY_SCOPE_SINGLE 4
-// RISCV64: #define __MEMORY_SCOPE_SYSTEM 0
-// RISCV64: #define __MEMORY_SCOPE_WRKGRP 2
-// RISCV64: #define __MEMORY_SCOPE_WVFRNT 3
+// RISCV64: #define __MEMORY_SCOPE_DEVICE 1
+// RISCV64: #define __MEMORY_SCOPE_SINGLE 4
+// RISCV64: #define __MEMORY_SCOPE_SYSTEM 0
+// RISCV64: #define __MEMORY_SCOPE_WRKGRP 2
+// RISCV64: #define __MEMORY_SCOPE_WVFRNT 3
// RISCV64: #define __NO_INLINE__ 1
// RISCV64: #define __POINTER_WIDTH__ 64
// RISCV64: #define __PRAGMA_REDEFINE_EXTNAME 1
diff --git a/clang/test/Preprocessor/predefined-win-macros.c b/clang/test/Preprocessor/predefined-win-macros.c
index b830dc39d477dd..14e2f584bd0938 100644
--- a/clang/test/Preprocessor/predefined-win-macros.c
+++ b/clang/test/Preprocessor/predefined-win-macros.c
@@ -3,7 +3,7 @@
// RUN: %clang_cc1 %s -x c++ -E -dM -triple x86_64-pc-win32 -fms-extensions -fms-compatibility \
// RUN: -fms-compatibility-version=19.00 -std=c++14 -o - | FileCheck -match-full-lines %s --check-prefix=CHECK-MS64
// RUN: %clang_cc1 %s -x c++ -E -dM -triple x86_64-pc-win32 -fms-extensions -fms-compatibility \
-// RUN: -fms-compatibility-version=19.00 -std=c++14 -o - | grep GCC | count 5
+// RUN: -fms-compatibility-version=19.00 -std=c++14 -o - | grep GCC | count 7
// CHECK-MS64: #define _INTEGRAL_MAX_BITS 64
// CHECK-MS64: #define _ISO_VOLATILE 1
// CHECK-MS64: #define _MSC_EXTENSIONS 1
@@ -26,7 +26,7 @@
// RUN: %clang_cc1 %s -x c++ -E -dM -triple i686-pc-win32 -fms-extensions -fms-compatibility \
// RUN: -fms-compatibility-version=19.00 -std=c++17 -o - | FileCheck -match-full-lines %s --check-prefix=CHECK-MS
// RUN: %clang_cc1 %s -x c++ -E -dM -triple i686-pc-win32 -fms-extensions -fms-compatibility \
-// RUN: -fms-compatibility-version=19.00 -std=c++17 -o - | grep GCC | count 5
+// RUN: -fms-compatibility-version=19.00 -std=c++17 -o - | grep GCC | count 7
// CHECK-MS: #define _INTEGRAL_MAX_BITS 64
// CHECK-MS: #define _ISO_VOLATILE 1
// CHECK-MS: #define _MSC_EXTENSIONS 1
@@ -39,6 +39,8 @@
// CHECK-MS-NOT: GNU
// CHECK-MS-NOT: GXX
// CHECK-MS: #define __GCC_ASM_FLAG_OUTPUTS__ 1
+// CHECK-MS: #define __GCC_CONSTRUCTIVE_SIZE {{.+}}
+// CHECK-MS: #define __GCC_DESTRUCTIVE_SIZE {{.+}}
// CHECK-MS: #define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_1 1
// CHECK-MS: #define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_2 1
// CHECK-MS: #define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 1
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