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| author | Anton Blanchard <anton@samba.org> | 2005-09-06 13:05:58 +1000 |
|---|---|---|
| committer | Paul Mackerras <paulus@samba.org> | 2005-09-06 16:07:53 +1000 |
| commit | b2c0ab17ba751abe13a28508b1ac7e9ca074cd87 (patch) | |
| tree | 08abcde7f48b3393afcae069e3668923ee3e4492 | |
| parent | 4721e2214b5fd6eca48caea76afb1bad3148930f (diff) | |
| download | linux-stable-b2c0ab17ba751abe13a28508b1ac7e9ca074cd87.tar.gz linux-stable-b2c0ab17ba751abe13a28508b1ac7e9ca074cd87.tar.bz2 linux-stable-b2c0ab17ba751abe13a28508b1ac7e9ca074cd87.zip | |
[PATCH] ppc64: speedup cmpxchg
cmpxchg has the following code:
__typeof__(*(ptr)) _o_ = (o);
__typeof__(*(ptr)) _n_ = (n);
Unfortunately it makes gcc 4.0 store and load the variables to the stack.
Eg in atomic_dec_and_test we get:
stw r10,112(r1)
stw r9,116(r1)
lwz r9,112(r1)
lwz r0,116(r1)
x86 is just casting the values so do that instead. Also change __xchg*
and __cmpxchg* to take unsigned values, removing a few sign extensions.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
| -rw-r--r-- | include/asm-ppc64/system.h | 19 |
1 files changed, 8 insertions, 11 deletions
diff --git a/include/asm-ppc64/system.h b/include/asm-ppc64/system.h index b9e1835351e9..c0396428cc3c 100644 --- a/include/asm-ppc64/system.h +++ b/include/asm-ppc64/system.h @@ -158,7 +158,7 @@ static inline int __is_processor(unsigned long pv) * is more like most of the other architectures. */ static __inline__ unsigned long -__xchg_u32(volatile int *m, unsigned long val) +__xchg_u32(volatile unsigned int *m, unsigned long val) { unsigned long dummy; @@ -200,7 +200,7 @@ __xchg_u64(volatile long *m, unsigned long val) extern void __xchg_called_with_bad_pointer(void); static __inline__ unsigned long -__xchg(volatile void *ptr, unsigned long x, int size) +__xchg(volatile void *ptr, unsigned long x, unsigned int size) { switch (size) { case 4: @@ -223,7 +223,7 @@ __xchg(volatile void *ptr, unsigned long x, int size) #define __HAVE_ARCH_CMPXCHG 1 static __inline__ unsigned long -__cmpxchg_u32(volatile int *p, int old, int new) +__cmpxchg_u32(volatile unsigned int *p, unsigned long old, unsigned long new) { unsigned int prev; @@ -271,7 +271,8 @@ __cmpxchg_u64(volatile long *p, unsigned long old, unsigned long new) extern void __cmpxchg_called_with_bad_pointer(void); static __inline__ unsigned long -__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size) +__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, + unsigned int size) { switch (size) { case 4: @@ -283,13 +284,9 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size) return old; } -#define cmpxchg(ptr,o,n) \ - ({ \ - __typeof__(*(ptr)) _o_ = (o); \ - __typeof__(*(ptr)) _n_ = (n); \ - (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \ - (unsigned long)_n_, sizeof(*(ptr))); \ - }) +#define cmpxchg(ptr,o,n)\ + ((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\ + (unsigned long)(n),sizeof(*(ptr)))) /* * We handle most unaligned accesses in hardware. On the other hand |