/* Machine-dependent pthreads configuration and inline functions. powerpc version. Copyright (C) 1996, 1997, 1998 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 modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with the GNU C Library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /* These routines are from Appendix G of the 'PowerPC 601 RISC Microprocessor User's Manual', by IBM and Motorola. */ /* For multiprocessor systems, we want to ensure all memory accesses are completed before we reset a lock. */ #if 0 /* on non multiprocessor systems, you can just: */ #define sync() /* nothing */ #else #define sync() __asm__ __volatile__ ("sync") #endif /* Get some notion of the current stack. Need not be exactly the top of the stack, just something somewhere in the current frame. */ #define CURRENT_STACK_FRAME stack_pointer 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 #if BROKEN_PPC_ASM_CR0 static #else extern inline #endif int __compare_and_swap (long *p, long oldval, long newval) { int ret; sync(); __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"); sync(); return ret == 0; }