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/* Machine-dependent pthreads configuration and inline functions.
*
* Copyright (C) 2005-2007 Atmel Corporation
*
* This file is subject to the terms and conditions of the GNU Lesser General
* Public License. See the file "COPYING.LIB" in the main directory of this
* archive for more details.
*/
#ifndef _PT_MACHINE_H
#define _PT_MACHINE_H 1
#include <features.h>
static inline int
_test_and_set (int *p, int v)
{
int result;
__asm__ __volatile__(
"/* Inline test and set */\n"
" xchg %[old], %[mem], %[new]"
: [old] "=&r"(result)
: [mem] "r"(p), [new] "r"(v)
: "memory");
return result;
}
#ifndef PT_EI
# define PT_EI extern inline
#endif
extern long int testandset (int *spinlock);
extern int __compare_and_swap (long int *p, long int oldval, long int newval);
/* Spinlock implementation; required. */
PT_EI long int
testandset (int *spinlock)
{
return _test_and_set(spinlock, 1);
}
/* Get some notion of the current stack. Need not be exactly the top
of the stack, just something somewhere in the current frame. */
#define CURRENT_STACK_FRAME stack_pointer
register char * stack_pointer __asm__ ("sp");
/* Compare-and-swap for semaphores. */
#define HAS_COMPARE_AND_SWAP
PT_EI int
__compare_and_swap(long int *p, long int oldval, long int newval)
{
long int result;
__asm__ __volatile__(
"/* Inline compare and swap */\n"
"1: ssrf 5\n"
" ld.w %[result], %[mem]\n"
" eor %[result], %[old]\n"
" brne 2f\n"
" stcond %[mem], %[new]\n"
" brne 1b\n"
"2:"
: [result] "=&r"(result), [mem] "=m"(*p)
: "m"(*p), [new] "r"(newval), [old] "r"(oldval)
: "cc", "memory");
return result == 0;
}
#endif /* pt-machine.h */
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