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Another attempt to improve atomic inc/dec

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git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@33119 72102866-910b-0410-8b05-ffd578937521
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rfm 2011-05-25 22:18:39 +00:00
parent e4e38170f9
commit 957ee2b8ef
2 changed files with 15 additions and 35 deletions
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6
ChangeLog
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@ -1,8 +1,10 @@
2011-05-25 Richard Frith-Macdonald <rfm@gnu.org> 2011-05-25 Richard Frith-Macdonald <rfm@gnu.org>
* Source/NSObject.m: * Source/NSObject.m:
Make last assembler attempt conditional ... I'm far from sure it's Further tweak of atomic assembly code ... don't really know what I'm
correct. doing here ... perhaps theoriginal author (mostly David?) knows more
about this assmebly stuff and implementation of atomic primitives on
different architectures?
2011-05-25 11:15 David Chisnall <theraven@gna.org> 2011-05-25 11:15 David Chisnall <theraven@gna.org>

44
Source/NSObject.m
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@ -214,8 +214,8 @@ typedef int32_t volatile *gsatomic_t;
typedef int32_t volatile *gsatomic_t; typedef int32_t volatile *gsatomic_t;
#define GSATOMICREAD(X) (*(X)) #define GSATOMICREAD(X) (*(X))
#define GSAtomicIncrement(X) __sync_fetch_and_add(X, 1) #define GSAtomicIncrement(X) __sync_add_and_fetch(X, 1)
#define GSAtomicDecrement(X) __sync_fetch_and_sub(X, 1) #define GSAtomicDecrement(X) __sync_sub_and_fetch(X, 1)
#elif defined(__linux__) && (defined(__i386__) || defined(__x86_64__)) #elif defined(__linux__) && (defined(__i386__) || defined(__x86_64__))
@ -228,18 +228,17 @@ typedef int32_t volatile *gsatomic_t;
#define ATOMIC_TESTING 1 #define ATOMIC_TESTING 1
#if defined(ATOMIC_TESTING)
static __inline__ int static __inline__ int
GSAtomicIncrement(gsatomic_t X) GSAtomicIncrement(gsatomic_t X)
{ {
register int tmp; register int tmp;
__asm__ __volatile__ ( __asm__ __volatile__ (
"movl $1, %0\n\t" "movl $1, %0\n"
"lock xaddl %0, %1" "lock xaddl %0, %1"
:"=r" (tmp), "=m" (*X) :"=r" (tmp), "=m" (*X)
:"r" (tmp), "m" (*X) :"r" (tmp), "m" (*X)
:"memory" ); :"memory" );
return tmp; return tmp + 1;
} }
static __inline__ int static __inline__ int
@ -247,35 +246,14 @@ GSAtomicDecrement(gsatomic_t X)
{ {
register int tmp; register int tmp;
__asm__ __volatile__ ( __asm__ __volatile__ (
"movl $1, %0\n\t" "movl $1, %0\n"
"negl %0\n\t" "negl %0\n"
"lock xaddl %0, %1" "lock xaddl %0, %1"
:"=r" (tmp), "=m" (*X) :"=r" (tmp), "=m" (*X)
:"r" (tmp), "m" (*X) :"r" (tmp), "m" (*X)
:"memory" ); :"memory" );
return tmp; return tmp - 1;
} }
#else
static __inline__ int
GSAtomicIncrement(gsatomic_t X)
{
__asm__ __volatile__ (
"lock addl $1, %0"
:"=m" (*X));
return *X;
}
static __inline__ int
GSAtomicDecrement(gsatomic_t X)
{
__asm__ __volatile__ (
"lock subl $1, %0"
:"=m" (*X));
return *X;
}
#endif
#elif defined(__PPC__) || defined(__POWERPC__) #elif defined(__PPC__) || defined(__POWERPC__)
@ -296,7 +274,7 @@ GSAtomicIncrement(gsatomic_t X)
:"=&r" (tmp) :"=&r" (tmp)
:"r" (X) :"r" (X)
:"cc", "memory"); :"cc", "memory");
return *X; return tmp;
} }
static __inline__ int static __inline__ int
@ -312,7 +290,7 @@ GSAtomicDecrement(gsatomic_t X)
:"=&r" (tmp) :"=&r" (tmp)
:"r" (X) :"r" (X)
:"cc", "memory"); :"cc", "memory");
return *X; return tmp;
} }
#elif defined(__m68k__) #elif defined(__m68k__)
@ -359,7 +337,7 @@ GSAtomicIncrement(gsatomic_t X)
" sc %0, %1 \n" " sc %0, %1 \n"
" beqz %0, 0b \n" " beqz %0, 0b \n"
:"=&r" (tmp), "=m" (*X)); :"=&r" (tmp), "=m" (*X));
return *X; return tmp;
} }
static __inline__ int static __inline__ int
@ -376,7 +354,7 @@ GSAtomicDecrement(gsatomic_t X)
" sc %0, %1 \n" " sc %0, %1 \n"
" beqz %0, 0b \n" " beqz %0, 0b \n"
:"=&r" (tmp), "=m" (*X)); :"=&r" (tmp), "=m" (*X));
return *X; return tmp;
} }
#endif #endif