From a9f5aa1cc96fc2c71f19a9c3e9dcbee0e78f83ca Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Tue, 15 Nov 2005 03:13:04 +0000 Subject: rename current stable linuxthreads to linuxthreads.old to prepare for import of latest glibc version --- .../linuxthreads.old/sysdeps/i386/pt-machine.h | 158 +++++++++++++++++++++ 1 file changed, 158 insertions(+) create mode 100644 libpthread/linuxthreads.old/sysdeps/i386/pt-machine.h (limited to 'libpthread/linuxthreads.old/sysdeps/i386/pt-machine.h') diff --git a/libpthread/linuxthreads.old/sysdeps/i386/pt-machine.h b/libpthread/linuxthreads.old/sysdeps/i386/pt-machine.h new file mode 100644 index 000000000..af1818d7b --- /dev/null +++ b/libpthread/linuxthreads.old/sysdeps/i386/pt-machine.h @@ -0,0 +1,158 @@ +/* Machine-dependent pthreads configuration and inline functions. + i386 version. + Copyright (C) 1996-2001, 2002, 2003 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Richard Henderson . + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 2.1 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser 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. */ + +#ifndef _PT_MACHINE_H +#define _PT_MACHINE_H 1 + +#ifndef __ASSEMBLER__ +#ifndef PT_EI +# define PT_EI extern inline __attribute__ ((always_inline)) +#endif + +extern long int testandset (int *spinlock); +extern int __compare_and_swap (long int *p, long int oldval, long int newval); + +/* 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 __builtin_frame_address (0) + + +/* See if we can optimize for newer cpus... */ +#if defined __GNUC__ && __GNUC__ >= 2 && \ + (defined __i486__ || defined __pentium__ || defined __pentiumpro__ || defined __pentium4__ || \ + defined __athlon__ || defined __k8__) + +/* Spinlock implementation; required. */ +PT_EI long int +testandset (int *spinlock) +{ + long int ret; + + __asm__ __volatile__ ( + "xchgl %0, %1" + : "=r" (ret), "=m" (*spinlock) + : "0" (1), "m" (*spinlock) + : "memory"); + + return ret; +} + +/* Compare-and-swap for semaphores. It's always available on i686. */ +#define HAS_COMPARE_AND_SWAP + +PT_EI int +__compare_and_swap (long int *p, long int oldval, long int newval) +{ + char ret; + long int readval; + + __asm__ __volatile__ ("lock; cmpxchgl %3, %1; sete %0" + : "=q" (ret), "=m" (*p), "=a" (readval) + : "r" (newval), "m" (*p), "a" (oldval) + : "memory"); + return ret; +} + +#if __ASSUME_LDT_WORKS > 0 +#include "../useldt.h" +#endif + +/* The P4 and above really want some help to prevent overheating. */ +#define BUSY_WAIT_NOP __asm__ ("rep; nop") + + +#else /* Generic i386 implementation */ + + + +/* Spinlock implementation; required. */ +PT_EI long int +testandset (int *spinlock) +{ + long int ret; + + __asm__ __volatile__( + "xchgl %0, %1" + : "=r"(ret), "=m"(*spinlock) + : "0"(1), "m"(*spinlock) + : "memory"); + + return ret; +} + + +/* Compare-and-swap for semaphores. + Available on the 486 and above, but not on the 386. + We test dynamically whether it's available or not. */ + +#define HAS_COMPARE_AND_SWAP +#define TEST_FOR_COMPARE_AND_SWAP + +PT_EI int +__compare_and_swap (long int *p, long int oldval, long int newval) +{ + char ret; + long int readval; + + __asm__ __volatile__ ("lock; cmpxchgl %3, %1; sete %0" + : "=q" (ret), "=m" (*p), "=a" (readval) + : "r" (newval), "m" (*p), "a" (oldval) + : "memory"); + return ret; +} + + +PT_EI int +get_eflags (void) +{ + int res; + __asm__ __volatile__ ("pushfl; popl %0" : "=r" (res) : ); + return res; +} + + +PT_EI void +set_eflags (int newflags) +{ + __asm__ __volatile__ ("pushl %0; popfl" : : "r" (newflags) : "cc"); +} + + +PT_EI int +compare_and_swap_is_available (void) +{ + int oldflags = get_eflags (); + int changed; + /* Flip AC bit in EFLAGS. */ + set_eflags (oldflags ^ 0x40000); + /* See if bit changed. */ + changed = (get_eflags () ^ oldflags) & 0x40000; + /* Restore EFLAGS. */ + set_eflags (oldflags); + /* If the AC flag did not change, it's a 386 and it lacks cmpxchg. + Otherwise, it's a 486 or above and it has cmpxchg. */ + return changed != 0; +} +#endif /* Generic i386 implementation */ + +#endif /* __ASSEMBLER__ */ + +#endif /* pt-machine.h */ -- cgit v1.2.3