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/* AMD GCN atomic operations
Copyright (C) 2020-2022 Free Software Foundation, Inc.
Contributed by Mentor Graphics.
This file is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 3, or (at your option) any
later version.
This file is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
#include <stdbool.h>
#define __SYNC_SUBWORD_COMPARE_AND_SWAP(TYPE, SIZE) \
\
TYPE \
__sync_val_compare_and_swap_##SIZE (TYPE *ptr, TYPE oldval, TYPE newval) \
{ \
unsigned int valmask = (1 << (SIZE * 8)) - 1; \
unsigned int *wordptr = (unsigned int *)((__UINTPTR_TYPE__ ) ptr & ~3UL); \
int shift = ((__UINTPTR_TYPE__ ) ptr & 3UL) * 8; \
unsigned int wordmask = ~(valmask << shift); \
unsigned int oldword = *wordptr; \
for (;;) \
{ \
TYPE prevval = (oldword >> shift) & valmask; \
if (__builtin_expect (prevval != oldval, 0)) \
return prevval; \
unsigned int newword = oldword & wordmask; \
newword |= ((unsigned int) newval) << shift; \
unsigned int prevword \
= __sync_val_compare_and_swap_4 (wordptr, oldword, newword); \
if (__builtin_expect (prevword == oldword, 1)) \
return oldval; \
oldword = prevword; \
} \
} \
\
bool \
__sync_bool_compare_and_swap_##SIZE (TYPE *ptr, TYPE oldval, TYPE newval) \
{ \
return __sync_val_compare_and_swap_##SIZE (ptr, oldval, newval) == oldval; \
}
__SYNC_SUBWORD_COMPARE_AND_SWAP (unsigned char, 1)
__SYNC_SUBWORD_COMPARE_AND_SWAP (unsigned short, 2)
#define __ATOMIC_COMPARE_EXCHANGE(TYPE,SIZE) \
bool \
__atomic_compare_exchange_##SIZE (TYPE *ptr, TYPE *expected, \
TYPE desired, bool weak, \
int success_memorder, int failure_memorder) \
{ \
unsigned int valmask = (1 << (SIZE * 8)) - 1; \
\
unsigned int *wordptr = (unsigned int *)((__UINTPTR_TYPE__ ) ptr & ~3UL); \
int ptrshift = ((__UINTPTR_TYPE__ ) ptr & 3UL) * 8; \
unsigned int wordmask = ~(valmask << ptrshift); \
\
unsigned int ptrword = *wordptr; \
unsigned int exptword = ptrword & wordmask; \
unsigned int newword = ptrword & wordmask; \
exptword |= ((unsigned int) *expected) << ptrshift; \
newword |= ((unsigned int) desired) << ptrshift; \
if (__atomic_compare_exchange_4 (wordptr, &exptword, newword, weak, \
success_memorder, failure_memorder)) \
return true; \
*expected = (TYPE) ((exptword >> ptrshift) & valmask); \
return false; \
}
__ATOMIC_COMPARE_EXCHANGE (unsigned char, 1)
__ATOMIC_COMPARE_EXCHANGE (unsigned short, 2)
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