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Merge "Replace __atomic_XXX with GCC __sync_XXX intrinsics."

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David Turner 2011-02-06 15:01:39 -08:00 committed by Android Code Review
commit 8db7bcb14f
2 changed files with 65 additions and 97 deletions
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97
libc/arch-x86/bionic/atomics_x86.S
View file

@ -73,100 +73,3 @@ __futex_syscall4:
popl %esi
popl %ebx
ret
/* int __atomic_cmpxchg(int old, int new, volatile int* addr) */
.text
.globl __atomic_cmpxchg
.type __atomic_cmpxchg, @function
.align 4
__atomic_cmpxchg:
mov 4(%esp), %eax /* old */
mov 8(%esp), %ecx /* new */
mov 12(%esp), %edx /* addr */
lock cmpxchg %ecx, (%edx)
jnz 1f
xor %eax, %eax
jmp 2f
1:
movl $1, %eax
2:
ret /* 0 == success, 1 == failure */
/* int __atomic_swap(int new, volatile int* addr) */
.text
.globl __atomic_swap
.type __atomic_swap, @function
.align 4
__atomic_swap:
mov 4(%esp), %ecx /* new */
mov 8(%esp), %edx /* addr */
lock xchg %ecx, (%edx)
mov %ecx, %eax
ret
/*
* int __atomic_dec(volatile int* addr)
*
* My x86 asm is really rusty.. this is probably suboptimal
*/
.text
.globl __atomic_dec
.type __atomic_dec, @function
.align 4
__atomic_dec:
pushl %ebx
pushl %esi
movl 12(%esp), %ebx /* addr */
1:
movl (%ebx), %esi /* old = *addr */
movl %esi, %edx
subl $1, %edx /* new = old - 1 */
pushl %ebx
pushl %edx
pushl %esi
call __atomic_cmpxchg
addl $12, %esp
test %eax, %eax
jnz 1b
movl %esi, %eax /* return old */
popl %esi
popl %ebx
ret
.text
/* int __atomic_inc(volatile int* addr) */
.globl __atomic_inc
.type __atomic_inc, @function
.align 4
__atomic_inc:
pushl %ebx
pushl %esi
movl 12(%esp), %ebx /* addr */
1:
movl (%ebx), %esi /* old = *addr */
movl %esi, %edx
addl $1, %edx /* new = old + 1 */
pushl %ebx
pushl %edx
pushl %esi
call __atomic_cmpxchg
addl $12, %esp
test %eax, %eax
jnz 1b
movl %esi, %eax /* return old */
popl %esi
popl %ebx
ret

65
libc/arch-x86/include/sys/atomics.h Normal file
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@ -0,0 +1,65 @@
/*
* Copyright (C) 2011 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef _SYS_ATOMICS_H
#define _SYS_ATOMICS_H
#include <sys/cdefs.h>
#include <sys/time.h>
__BEGIN_DECLS
static inline __attribute__((always_inline)) int
__atomic_cmpxchg(int old, int _new, volatile int *ptr)
{
return !__sync_bool_compare_and_swap (ptr, old, _new);
}
static inline __attribute__((always_inline)) int
__atomic_swap(int _new, volatile int *ptr)
{
return __sync_lock_test_and_set(ptr, _new);
}
static inline __attribute__((always_inline)) int
__atomic_dec(volatile int *ptr)
{
return __sync_fetch_and_sub (ptr, 1);
}
static inline __attribute__((always_inline)) int
__atomic_inc(volatile int *ptr)
{
return __sync_fetch_and_add (ptr, 1);
}
int __futex_wait(volatile void *ftx, int val, const struct timespec *timeout);
int __futex_wake(volatile void *ftx, int count);
__END_DECLS
#endif /* _SYS_ATOMICS_H */