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Define atomic_exchange and atomic_decrement_if_positive if not already defined. Add some __builtin_expect.

This commit is contained in:
Ulrich Drepper 2003-03-20 10:11:43 +00:00
parent 100a7100a7
commit 5132931e18
1 changed files with 47 additions and 5 deletions
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52
include/atomic.h
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@ -49,6 +49,24 @@
#endif
/* Store NEWVALUE in *MEM and return the old value. */
#ifndef atomic_exchange
# define atomic_exchange(mem, newvalue) \
({ __typeof (*mem) __oldval; \
__typeof (mem) __memp = (mem); \
__typeof (*mem) __value = (newvalue); \
\
do \
__oldval = (*__memp); \
while (__builtin_expect (atomic_compare_and_exchange_acq (__memp, \
__value, \
__oldval), 0));\
\
__oldval; })
#endif
/* Add VALUE to *MEM and return the old value of *MEM. */
#ifndef atomic_exchange_and_add
# define atomic_exchange_and_add(mem, value) \
({ __typeof (*mem) __oldval; \
@ -57,10 +75,12 @@
\
do \
__oldval = (*__memp); \
while (atomic_compare_and_exchange_acq (__memp, __oldval + __value, \
__oldval)); \
while (__builtin_expect (atomic_compare_and_exchange_acq (__memp, \
__oldval \
+ __value, \
__oldval), 0));\
\
__oldval + __value; })
__oldval; })
#endif
@ -91,6 +111,26 @@
#endif
/* Decrement *MEM if it is > 0, and return the old value. */
#ifndef atomic_decrement_if_positive(mem) \
({ __typeof (*mem) __val; \
__typeof (*mem) __oldval; \
__typeof (mem) __memp; \
\
__val = *__memp; \
do \
{ \
if (__builtin_expect (__val <= 0, 0)) \
break; \
__oldval = __val; \
__val = atomic_compare_and_exchange_acq (__memp, __oldval - 1, \
__oldval); \
} \
while (__builtin_expect (__val != __oldval, 0)); \
__val; })
#endif
#ifndef atomic_add_negative
# define atomic_add_negative(mem, value) \
(atomic_exchange_and_add (mem, value) < 0)
@ -117,8 +157,10 @@
\
do \
__oldval = (*__memp); \
while (atomic_compare_and_exchange_acq (__memp, \
__oldval | __mask, __oldval)); \
while (__builtin_expect (atomic_compare_and_exchange_acq (__memp, \
__oldval \
| __mask, \
__oldval), 0));\
\
__oldval & __mask; })
#endif