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authorEric Andersen <andersen@codepoet.org>2003-03-03 20:58:42 +0000
committerEric Andersen <andersen@codepoet.org>2003-03-03 20:58:42 +0000
commit67eff66438688fddebe41f77fd252a3b2b135271 (patch)
tree18dbee3e9afe50d27095140198e2aa34df1de061 /libpthread/linuxthreads/sysdeps/i386/pt-machine.h
parent2229d0fa131387b9b8ad16ac88347350a080aeb5 (diff)
Initial effort at adding profiling support.
Diffstat (limited to 'libpthread/linuxthreads/sysdeps/i386/pt-machine.h')
-rw-r--r--libpthread/linuxthreads/sysdeps/i386/pt-machine.h48
1 files changed, 48 insertions, 0 deletions
diff --git a/libpthread/linuxthreads/sysdeps/i386/pt-machine.h b/libpthread/linuxthreads/sysdeps/i386/pt-machine.h
index 79c69b549..e8a9b4e67 100644
--- a/libpthread/linuxthreads/sysdeps/i386/pt-machine.h
+++ b/libpthread/linuxthreads/sysdeps/i386/pt-machine.h
@@ -35,6 +35,52 @@ 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__
+
+/* 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)
@@ -103,6 +149,8 @@ compare_and_swap_is_available (void)
Otherwise, it's a 486 or above and it has cmpxchg. */
return changed != 0;
}
+#endif /* Generic i386 implementation */
+
#endif /* __ASSEMBLER__ */
#endif /* pt-machine.h */