Hello!
This patch avoids unnecessary clearing of 4th argument for futex_wake
syscall for 32bit targets.
2015-05-28 Uros Bizjak <ubiz...@gmail.com>
* config/linux/x86/futex.h (sys_futex0) [!__x86_64__]: Remove function.
(futex_wait) [!__x86_64__]: Use __asm operand instead of sys_futex0.
(futex_wake) [!__x86_64__]: Ditto.
Tested on x86_64-linux-gnu {,-m32} and committed to mainline SVN.
Uros.
Index: config/linux/x86/futex.h
===================================================================
--- config/linux/x86/futex.h (revision 223796)
+++ config/linux/x86/futex.h (working copy)
@@ -81,43 +81,49 @@
# define SYS_futex 240
# endif
-static inline long
-sys_futex0 (int *addr, int op, int val)
+static inline void
+futex_wait (int *addr, int val)
{
long res;
__asm volatile ("int $0x80"
: "=a" (res)
- : "0"(SYS_futex), "b" (addr), "c"(op),
- "d"(val), "S"(0)
+ : "0" (SYS_futex), "b" (addr), "c" (gomp_futex_wait),
+ "d" (val), "S" (0)
: "memory");
- return res;
-}
-
-static inline void
-futex_wait (int *addr, int val)
-{
- long res = sys_futex0 (addr, gomp_futex_wait, val);
if (__builtin_expect (res == -ENOSYS, 0))
{
gomp_futex_wait &= ~FUTEX_PRIVATE_FLAG;
gomp_futex_wake &= ~FUTEX_PRIVATE_FLAG;
- sys_futex0 (addr, gomp_futex_wait, val);
+ __asm volatile ("int $0x80"
+ : "=a" (res)
+ : "0" (SYS_futex), "b" (addr), "c" (gomp_futex_wait),
+ "d" (val), "S" (0)
+ : "memory");
}
}
static inline void
futex_wake (int *addr, int count)
{
- long res = sys_futex0 (addr, gomp_futex_wake, count);
+ long res;
+
+ __asm volatile ("int $0x80"
+ : "=a" (res)
+ : "0" (SYS_futex), "b" (addr), "c" (gomp_futex_wake),
+ "d" (count)
+ : "memory");
if (__builtin_expect (res == -ENOSYS, 0))
{
gomp_futex_wait &= ~FUTEX_PRIVATE_FLAG;
gomp_futex_wake &= ~FUTEX_PRIVATE_FLAG;
- sys_futex0 (addr, gomp_futex_wake, count);
+ __asm volatile ("int $0x80"
+ : "=a" (res)
+ : "0" (SYS_futex), "b" (addr), "c" (gomp_futex_wake),
+ "d" (count)
+ : "memory");
}
}
-
#endif /* __x86_64__ */
static inline void
