diff options
Diffstat (limited to 'linuxthreads')
| -rw-r--r-- | linuxthreads/ChangeLog | 7 | ||||
| -rw-r--r-- | linuxthreads/sysdeps/powerpc/pt-machine.h | 36 |
2 files changed, 34 insertions, 9 deletions
diff --git a/linuxthreads/ChangeLog b/linuxthreads/ChangeLog index 371bd4b8f5..d746ee31dd 100644 --- a/linuxthreads/ChangeLog +++ b/linuxthreads/ChangeLog @@ -1,3 +1,10 @@ +2001-05-09 Geoff Keating <geoffk@redhat.com> + + * sysdeps/powerpc/pt-machine.h + (HAS_COMPARE_AND_SWAP_WITH_RELEASE_SEMANTICS): Define. + (__compare_and_swap): Remove memory barriers. + (__compare_and_swap_with_release_semantics): New function. + 2001-04-24 Andreas Jaeger <aj@suse.de> * wrapsyscall.c: send* and recv* return ssize_t. diff --git a/linuxthreads/sysdeps/powerpc/pt-machine.h b/linuxthreads/sysdeps/powerpc/pt-machine.h index 39defcd00f..5a684e9b13 100644 --- a/linuxthreads/sysdeps/powerpc/pt-machine.h +++ b/linuxthreads/sysdeps/powerpc/pt-machine.h @@ -1,6 +1,6 @@ /* Machine-dependent pthreads configuration and inline functions. powerpc version. - Copyright (C) 1996, 1997, 1998, 2000 Free Software Foundation, Inc. + Copyright (C) 1996, 1997, 1998, 2000, 2001 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or @@ -38,20 +38,14 @@ register char * stack_pointer __asm__ ("r1"); /* Compare-and-swap for semaphores. */ /* note that test-and-set(x) is the same as !compare-and-swap(x, 0, 1) */ -#define HAS_COMPARE_AND_SWAP +#define HAS_COMPARE_AND_SWAP_WITH_RELEASE_SEMANTICS #define IMPLEMENT_TAS_WITH_CAS -#if BROKEN_PPC_ASM_CR0 -static -#else -PT_EI -#endif -int +PT_EI int __compare_and_swap (long int *p, long int oldval, long int newval) { int ret; - MEMORY_BARRIER (); __asm__ __volatile__ ( "0: lwarx %0,0,%1 ;" " xor. %0,%3,%0;" @@ -62,6 +56,30 @@ __compare_and_swap (long int *p, long int oldval, long int newval) : "=&r"(ret) : "r"(p), "r"(newval), "r"(oldval) : "cr0", "memory"); + /* This version of __compare_and_swap is to be used when acquiring + a lock, so we don't need to worry about whether other memory + operations have completed, but we do need to be sure that any loads + after this point really occur after we have acquired the lock. */ + __asm__ __volatile__ ("isync" : : : "memory"); + return ret == 0; +} + +PT_EI int +__compare_and_swap_with_release_semantics (long int *p, + long int oldval, long int newval) +{ + int ret; + MEMORY_BARRIER (); + __asm__ __volatile__ ( + "0: lwarx %0,0,%1 ;" + " xor. %0,%3,%0;" + " bne 1f;" + " stwcx. %2,0,%1;" + " bne- 0b;" + "1: " + : "=&r"(ret) + : "r"(p), "r"(newval), "r"(oldval) + : "cr0", "memory"); return ret == 0; } |