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Change atomic_exchange_and_add to return the old value.

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This commit is contained in:
Ulrich Drepper 2003-03-20 09:03:23 +00:00
parent 91958edc84
commit 3dbe0d9517
1 changed files with 12 additions and 21 deletions
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33
sysdeps/i386/i486/bits/atomic.h
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@ -123,33 +123,24 @@ typedef uintmax_t uatomic_max_t;
({ __typeof (*mem) result; \
__typeof (value) addval = (value); \
if (sizeof (*mem) == 1) \
{ \
__asm __volatile (LOCK "xaddb %b0, %1" \
: "=r" (result), "=m" (*mem) \
: "0" (addval), "1" (*mem)); \
result += addval; \
} \
__asm __volatile (LOCK "xaddb %b0, %1" \
: "=r" (result), "=m" (*mem) \
: "0" (addval), "1" (*mem)); \
else if (sizeof (*mem) == 2) \
{ \
__asm __volatile (LOCK "xaddw %w0, %1" \
: "=r" (result), "=m" (*mem) \
: "0" (addval), "1" (*mem)); \
result += addval; \
} \
__asm __volatile (LOCK "xaddw %w0, %1" \
: "=r" (result), "=m" (*mem) \
: "0" (addval), "1" (*mem)); \
else if (sizeof (*mem) == 4) \
{ \
__asm __volatile (LOCK "xaddl %0, %1" \
: "=r" (result), "=m" (*mem) \
: "0" (addval), "1" (*mem)); \
result += addval; \
} \
__asm __volatile (LOCK "xaddl %0, %1" \
: "=r" (result), "=m" (*mem) \
: "0" (addval), "1" (*mem)); \
else \
{ \
__typeof (*mem) oldval; \
__typeof (mem) memp = (mem); \
do \
result = (oldval = *memp) + addval; \
while (__arch_compare_and_exchange_64_acq (memp, result, oldval)); \
result = *memp; \
while (__arch_compare_and_exchange_64_acq (memp, result + addval, \
result)); \
} \
result; })