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/*
* Copyright (C) 2005, 2007, 2008 Internet Systems Consortium, Inc. ("ISC")
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
/* $Id: atomic.h,v 1.6 2008/01/24 23:47:00 tbox Exp $ */
#ifndef ISC_ATOMIC_H
#define ISC_ATOMIC_H 1
#include <isc/platform.h>
#include <isc/types.h>
#ifdef ISC_PLATFORM_USEGCCASM
/* We share the gcc-version with x86_32 */
#error "impossible case. check build configuration"
#elif defined(ISC_PLATFORM_USESTDASM)
/*
* The followings are "generic" assembly code which implements the same
* functionality in case the gcc extension cannot be used. It should be
* better to avoid inlining below, since we directly refer to specific
* registers for arguments, which would not actually correspond to the
* intended address or value in the embedded mnemonic.
*/
#include <isc/util.h> /* for 'UNUSED' macro */
static isc_int32_t
isc_atomic_xadd(isc_int32_t *p, isc_int32_t val) {
UNUSED(p);
UNUSED(val);
__asm (
"movq %rdi, %rdx\n"
"movl %esi, %eax\n"
#ifdef ISC_PLATFORM_USETHREADS
"lock;"
#endif
"xadd %eax, (%rdx)\n"
/*
* XXX: assume %eax will be used as the return value.
*/
);
}
#ifdef ISC_PLATFORM_HAVEXADDQ
static isc_int64_t
isc_atomic_xaddq(isc_int64_t *p, isc_int64_t val) {
UNUSED(p);
UNUSED(val);
__asm (
"movq %rdi, %rdx\n"
"movq %rsi, %rax\n"
#ifdef ISC_PLATFORM_USETHREADS
"lock;"
#endif
"xaddq %rax, (%rdx)\n"
/*
* XXX: assume %rax will be used as the return value.
*/
);
}
#endif
static void
isc_atomic_store(isc_int32_t *p, isc_int32_t val) {
UNUSED(p);
UNUSED(val);
__asm (
"movq %rdi, %rax\n"
"movl %esi, %edx\n"
#ifdef ISC_PLATFORM_USETHREADS
"lock;"
#endif
"xchgl (%rax), %edx\n"
/*
* XXX: assume %rax will be used as the return value.
*/
);
}
static isc_int32_t
isc_atomic_cmpxchg(isc_int32_t *p, isc_int32_t cmpval, isc_int32_t val) {
UNUSED(p);
UNUSED(cmpval);
UNUSED(val);
__asm (
"movl %edx, %ecx\n"
"movl %esi, %eax\n"
"movq %rdi, %rdx\n"
#ifdef ISC_PLATFORM_USETHREADS
"lock;"
#endif
/*
* If (%rdi) == %eax then (%rdi) := %edx.
* %eax is set to old (%ecx), which will be the return value.
*/
"cmpxchgl %ecx, (%rdx)"
);
}
#else /* !ISC_PLATFORM_USEGCCASM && !ISC_PLATFORM_USESTDASM */
#error "unsupported compiler. disable atomic ops by --disable-atomic"
#endif
#endif /* ISC_ATOMIC_H */
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