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Diffstat (limited to 'libpthread/linuxthreads/sysdeps/i386/pt-machine.h')
-rw-r--r--libpthread/linuxthreads/sysdeps/i386/pt-machine.h93
1 files changed, 32 insertions, 61 deletions
diff --git a/libpthread/linuxthreads/sysdeps/i386/pt-machine.h b/libpthread/linuxthreads/sysdeps/i386/pt-machine.h
index 24c5e6c7c..82a5cf077 100644
--- a/libpthread/linuxthreads/sysdeps/i386/pt-machine.h
+++ b/libpthread/linuxthreads/sysdeps/i386/pt-machine.h
@@ -18,14 +18,17 @@
License along with the GNU C Library; see the file COPYING.LIB. If
not, see <http://www.gnu.org/licenses/>. */
+#if defined __pentiumpro__ || defined __pentium4__ || defined __athlon__ || \
+ defined __k8__
+# include "i686/pt-machine.h"
+#else
+
#ifndef _PT_MACHINE_H
#define _PT_MACHINE_H 1
-#include <features.h>
-
#ifndef __ASSEMBLER__
#ifndef PT_EI
-# define PT_EI __extern_always_inline __attribute__((visibility("hidden")))
+# define PT_EI __extern_always_inline
#endif
extern long int testandset (int *spinlock);
@@ -36,54 +39,6 @@ extern int __compare_and_swap (long int *p, long int oldval, long int newval);
#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 defined(__ASSUME_LDT_WORKS) && __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 */
-
-extern int compare_and_swap_is_available (void);
-
/* Spinlock implementation; required. */
PT_EI long int
testandset (int *spinlock)
@@ -120,27 +75,43 @@ __compare_and_swap (long int *p, long int oldval, long int newval)
return ret;
}
+
+PT_EI int get_eflags (void);
+PT_EI int
+get_eflags (void)
+{
+ int res;
+ __asm__ __volatile__ ("pushfl; popl %0" : "=r" (res) : );
+ return res;
+}
+
+
+PT_EI void set_eflags (int newflags);
+PT_EI void
+set_eflags (int newflags)
+{
+ __asm__ __volatile__ ("pushl %0; popfl" : : "r" (newflags) : "cc");
+}
+
+
+PT_EI int compare_and_swap_is_available (void);
PT_EI int
compare_and_swap_is_available (void)
{
+ int oldflags = get_eflags ();
int changed;
- int oldflags;
- /* get EFLAGS */
- __asm__ __volatile__ ("pushfl; popl %0" : "=r" (oldflags) : );
/* Flip AC bit in EFLAGS. */
- __asm__ __volatile__ ("pushl %0; popfl" : : "r" (oldflags ^ 0x40000) : "cc");
- /* reread EFLAGS */
- __asm__ __volatile__ ("pushfl; popl %0" : "=r" (changed) : );
+ set_eflags (oldflags ^ 0x40000);
/* See if bit changed. */
- changed = (changed ^ oldflags) & 0x40000;
+ changed = (get_eflags () ^ oldflags) & 0x40000;
/* Restore EFLAGS. */
- __asm__ __volatile__ ("pushl %0; popfl" : : "r" (oldflags) : "cc");
+ 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 */
+
+#endif