[PATCH] D28213: [Frontend] Correct values of ATOMIC_*_LOCK_FREE to match builtin

Ryan Prichard via Phabricator via cfe-commits cfe-commits at lists.llvm.org
Thu Jul 21 17:24:57 PDT 2022


This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rG02a25279aedc: [Frontend] Correct values of ATOMIC_*_LOCK_FREE to match builtin (authored by rprichard).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D28213/new/

https://reviews.llvm.org/D28213

Files:
  clang/lib/Frontend/InitPreprocessor.cpp
  clang/test/Preprocessor/init-x86.c
  clang/test/Sema/atomic-ops.c


Index: clang/test/Sema/atomic-ops.c
===================================================================
--- clang/test/Sema/atomic-ops.c
+++ clang/test/Sema/atomic-ops.c
@@ -33,11 +33,7 @@
 _Static_assert(__GCC_ATOMIC_INT_LOCK_FREE == __CLANG_ATOMIC_INT_LOCK_FREE, "");
 _Static_assert(__GCC_ATOMIC_LONG_LOCK_FREE == 2, "");
 _Static_assert(__GCC_ATOMIC_LONG_LOCK_FREE == __CLANG_ATOMIC_LONG_LOCK_FREE, "");
-#ifdef __i386__
-_Static_assert(__GCC_ATOMIC_LLONG_LOCK_FREE == 1, "");
-#else
 _Static_assert(__GCC_ATOMIC_LLONG_LOCK_FREE == 2, "");
-#endif
 _Static_assert(__GCC_ATOMIC_LLONG_LOCK_FREE == __CLANG_ATOMIC_LLONG_LOCK_FREE, "");
 _Static_assert(__GCC_ATOMIC_POINTER_LOCK_FREE == 2, "");
 _Static_assert(__GCC_ATOMIC_POINTER_LOCK_FREE == __CLANG_ATOMIC_POINTER_LOCK_FREE, "");
Index: clang/test/Preprocessor/init-x86.c
===================================================================
--- clang/test/Preprocessor/init-x86.c
+++ clang/test/Preprocessor/init-x86.c
@@ -185,9 +185,9 @@
 // I386:#define __i386__ 1
 // I386:#define i386 1
 
-// RUN: %clang_cc1 -E -dM -ffreestanding -fgnuc-version=4.2.1 -triple=i386-pc-linux-gnu -target-cpu pentium4 < /dev/null | FileCheck -match-full-lines -check-prefix I386-LINUX -check-prefix I386-LINUX-ALIGN32 %s
-// RUN: %clang_cc1 -x c++ -E -dM -ffreestanding -fgnuc-version=4.2.1 -triple=i386-pc-linux-gnu -target-cpu pentium4 < /dev/null | FileCheck -match-full-lines -check-prefix I386-LINUX -check-prefix I386-LINUX-CXX -check-prefix I386-LINUX-ALIGN32 %s
-// RUN: %clang_cc1 -E -dM -ffreestanding -fgnuc-version=4.2.1 -triple=i386-pc-linux-gnu -target-cpu pentium4 -malign-double < /dev/null | FileCheck -match-full-lines -check-prefix I386-LINUX -check-prefix I386-LINUX-ALIGN64 %s
+// RUN: %clang_cc1 -E -dM -ffreestanding -fgnuc-version=4.2.1 -triple=i386-pc-linux-gnu -target-cpu i486 < /dev/null | FileCheck -match-full-lines -check-prefix I386-LINUX -check-prefix I386-LINUX-ALIGN32 %s
+// RUN: %clang_cc1 -E -dM -ffreestanding -fgnuc-version=4.2.1 -triple=i386-pc-linux-gnu -target-cpu pentium4 < /dev/null | FileCheck -match-full-lines -check-prefix I386-LINUX -check-prefix I386-LINUX-ALIGN64 %s
+// RUN: %clang_cc1 -x c++ -E -dM -ffreestanding -fgnuc-version=4.2.1 -triple=i386-pc-linux-gnu -target-cpu pentium4 < /dev/null | FileCheck -match-full-lines -check-prefix I386-LINUX -check-prefix I386-LINUX-ALIGN64 -check-prefix I386-LINUX-CXX %s
 //
 // I386-LINUX-NOT:#define _LP64
 // I386-LINUX:#define __BIGGEST_ALIGNMENT__ 16
Index: clang/lib/Frontend/InitPreprocessor.cpp
===================================================================
--- clang/lib/Frontend/InitPreprocessor.cpp
+++ clang/lib/Frontend/InitPreprocessor.cpp
@@ -298,12 +298,12 @@
 
 /// Get the value the ATOMIC_*_LOCK_FREE macro should have for a type with
 /// the specified properties.
-static const char *getLockFreeValue(unsigned TypeWidth, unsigned TypeAlign,
-                                    unsigned InlineWidth) {
+static const char *getLockFreeValue(unsigned TypeWidth, unsigned InlineWidth) {
   // Fully-aligned, power-of-2 sizes no larger than the inline
   // width will be inlined as lock-free operations.
-  if (TypeWidth == TypeAlign && (TypeWidth & (TypeWidth - 1)) == 0 &&
-      TypeWidth <= InlineWidth)
+  // Note: we do not need to check alignment since _Atomic(T) is always
+  // appropriately-aligned in clang.
+  if ((TypeWidth & (TypeWidth - 1)) == 0 && TypeWidth <= InlineWidth)
     return "2"; // "always lock free"
   // We cannot be certain what operations the lib calls might be
   // able to implement as lock-free on future processors.
@@ -1142,7 +1142,6 @@
 #define DEFINE_LOCK_FREE_MACRO(TYPE, Type)                                     \
   Builder.defineMacro(Prefix + #TYPE "_LOCK_FREE",                             \
                       getLockFreeValue(TI.get##Type##Width(),                  \
-                                       TI.get##Type##Align(),                  \
                                        InlineWidthBits));
     DEFINE_LOCK_FREE_MACRO(BOOL, Bool);
     DEFINE_LOCK_FREE_MACRO(CHAR, Char);
@@ -1157,7 +1156,6 @@
     DEFINE_LOCK_FREE_MACRO(LLONG, LongLong);
     Builder.defineMacro(Prefix + "POINTER_LOCK_FREE",
                         getLockFreeValue(TI.getPointerWidth(0),
-                                         TI.getPointerAlign(0),
                                          InlineWidthBits));
 #undef DEFINE_LOCK_FREE_MACRO
   };


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D28213.446663.patch
Type: text/x-patch
Size: 4454 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20220722/e8aa2039/attachment-0001.bin>


More information about the cfe-commits mailing list