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/*
* File : cas.h
* Author : Jérémy Zurcher <jeremy@asynk.ch>
* Date : 25/01/13
* License :
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
*/
#ifndef _CAS_H_
#define _CAS_H_
# ifdef __cplusplus
extern "C" {
# endif /* __cplusplus */
#include <stdint.h>
#if defined(__i386__) && defined(__GNUC__)
#define _cas_field_t uint32_t
#define _cas_aligned 8
#elif defined(__x86_64__) && defined(__GNUC__)
#define _cas_field_t uint64_t
#define _cas_aligned 16
#else
#error "cas not implemented yet for your arch"
#endif
struct _cas_pointer_t
{
_cas_field_t lo;
_cas_field_t hi;
} __attribute__ (( __aligned__( _cas_aligned ) ));
typedef struct _cas_pointer_t cas_pointer_t;
#define _hi(p,v) ((p).hi=(_cas_field_t)(v))
#define _lo(p,v) ((p).lo=(_cas_field_t)(v))
#define _hi_eq(p,v) ((p).hi==(_cas_field_t)(v))
#define _lo_eq(p,v) ((p).lo==(_cas_field_t)(v))
inline int cas(volatile cas_pointer_t* mem, cas_pointer_t old_val, cas_pointer_t new_val)
{
char success;
#if defined(__i386__) && defined(__GNUC__)
asm volatile("lock cmpxchg8b (%6);"
"setz %7;"
: "=a" ( old_val.lo ),
"=d" ( old_val.hi )
: "0" ( old_val.lo ),
"1" ( old_val.hi ),
"b" ( new_val.lo ),
"c" ( new_val.hi ),
"r" ( mem ),
"m" ( success )
: "cc", "memory"
);
#elif defined(__x86_64__) && defined(__GNUC__)
asm volatile (
"lock cmpxchg16b %1;"
"setz %0;"
: "=q" ( success )
, "+m" ( *mem )
, "+d" ( old_val.hi )
, "+a" ( old_val.lo )
: "c" ( new_val.hi )
, "b" ( new_val.lo )
: "cc", "memory"
);
#endif
return (int)success;
}
# ifdef __cplusplus
}
# endif /* __cplusplus */
# endif /* _CAS_H_ */
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