diff options
| author | Uros Bizjak <ubizjak@gmail.com> | 2025-09-08 14:38:22 +0200 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2025-09-09 07:51:41 -0700 |
| commit | 935ee691bce7aa8c957714deea4868e5aefb52c9 (patch) | |
| tree | 5717ee513c5606c1f00d4c1ceb4edd8fa8c3ec30 | |
| parent | e6b5ad1b1d9f8dcb80b711747f3abffec29408e3 (diff) | |
x86: Define atomic_exchange_acq using __atomic_exchange_n
The resulting libc.so is identical on both x86_64 and
i386 targets compared to unpatched builds:
$ sha1sum libc-x86_64-old.so libc-x86_64-new.so
74eca1b87f2ecc9757a984c089a582b7615d93e7 libc-x86_64-old.so
74eca1b87f2ecc9757a984c089a582b7615d93e7 libc-x86_64-new.so
$ sha1sum libc-i386-old.so libc-i386-new.so
882bbab8324f79f4fbc85224c4c914fc6822ece7 libc-i386-old.so
882bbab8324f79f4fbc85224c4c914fc6822ece7 libc-i386-new.so
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>
Cc: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
Cc: Collin Funk <collin.funk1@gmail.com>
Cc: H.J.Lu <hjl.tools@gmail.com>
Cc: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
| -rw-r--r-- | sysdeps/x86/atomic-machine.h | 29 |
1 files changed, 1 insertions, 28 deletions
diff --git a/sysdeps/x86/atomic-machine.h b/sysdeps/x86/atomic-machine.h index c0c2c3437a..ebe8e978e5 100644 --- a/sysdeps/x86/atomic-machine.h +++ b/sysdeps/x86/atomic-machine.h @@ -19,9 +19,6 @@ #ifndef _X86_ATOMIC_MACHINE_H #define _X86_ATOMIC_MACHINE_H 1 -#include <stdint.h> -#include <libc-pointer-arith.h> /* For cast_to_integer. */ - #define USE_ATOMIC_COMPILER_BUILTINS 1 #ifdef __x86_64__ @@ -41,32 +38,8 @@ #define atomic_compare_and_exchange_bool_acq(mem, newval, oldval) \ (! __sync_bool_compare_and_swap (mem, oldval, newval)) -/* Note that we need no lock prefix. */ #define atomic_exchange_acq(mem, newvalue) \ - ({ __typeof (*mem) result; \ - if (sizeof (*mem) == 1) \ - __asm __volatile ("xchgb %b0, %1" \ - : "=q" (result), "=m" (*mem) \ - : "0" (newvalue), "m" (*mem)); \ - else if (sizeof (*mem) == 2) \ - __asm __volatile ("xchgw %w0, %1" \ - : "=r" (result), "=m" (*mem) \ - : "0" (newvalue), "m" (*mem)); \ - else if (sizeof (*mem) == 4) \ - __asm __volatile ("xchgl %0, %1" \ - : "=r" (result), "=m" (*mem) \ - : "0" (newvalue), "m" (*mem)); \ - else if (__HAVE_64B_ATOMICS) \ - __asm __volatile ("xchgq %q0, %1" \ - : "=r" (result), "=m" (*mem) \ - : "0" ((int64_t) cast_to_integer (newvalue)), \ - "m" (*mem)); \ - else \ - { \ - result = 0; \ - __atomic_link_error (); \ - } \ - result; }) + __atomic_exchange_n (mem, newvalue, __ATOMIC_ACQUIRE) /* ??? Remove when catomic_exchange_and_add fallback uses __atomic_fetch_add. */ |