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// Low-level functions for atomic operations: ARM version -*- C++ -*-
// Copyright (C) 2000, 2001 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library 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 2, or (at your option)
// any later version.
// This library 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.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING. If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.
// As a special exception, you may use this file as part of a free software
// library without restriction. Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License. This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.
#ifndef _BITS_ATOMICITY_H
#define _BITS_ATOMICITY_H 1
typedef int _Atomic_word;
static inline _Atomic_word
__attribute__ ((__unused__))
__exchange_and_add (volatile _Atomic_word* __mem, int __val)
{
_Atomic_word __tmp, __tmp2, __result;
#ifdef __thumb__
/* Since this function is inlined, we can't be sure of the alignment. */
__asm__ __volatile__ (
"ldr %0, 4f \n\t"
"bx %0 \n\t"
".align 0 \n"
"4:\t"
".word 0f \n\t"
".code 32 \n"
"0:\t"
"ldr %0, [%3] \n\t"
"add %1, %0, %4 \n\t"
"swp %2, %1, [%3] \n\t"
"cmp %0, %2 \n\t"
"swpne %1, %2, [%3] \n\t"
"bne 0b \n\t"
"ldr %1, 1f \n\t"
"bx %1 \n"
"1:\t"
".word 2f \n\t"
".code 16 \n"
"2:\n"
: "=&l"(__result), "=&r"(__tmp), "=&r"(__tmp2)
: "r" (__mem), "r"(__val)
: "cc", "memory");
#else
__asm__ __volatile__ (
"\n"
"0:\t"
"ldr %0, [%3] \n\t"
"add %1, %0, %4 \n\t"
"swp %2, %1, [%3] \n\t"
"cmp %0, %2 \n\t"
"swpne %1, %2, [%3] \n\t"
"bne 0b \n\t"
""
: "=&r"(__result), "=&r"(__tmp), "=&r"(__tmp2)
: "r" (__mem), "r"(__val)
: "cc", "memory");
#endif
return __result;
}
static inline void
__attribute__ ((__unused__))
__atomic_add (volatile _Atomic_word *__mem, int __val)
{
_Atomic_word __tmp, __tmp2, __tmp3;
#ifdef __thumb__
/* Since this function is inlined, we can't be sure of the alignment. */
__asm__ __volatile__ (
"ldr %0, 4f \n\t"
"bx %0 \n\t"
".align 0\n"
"4:\t"
".word 0f \n\t"
".code 32 \n"
"0:\t"
"ldr %0, [%3] \n\t"
"add %1, %0, %4 \n\t"
"swp %2, %1, [%3] \n\t"
"cmp %0, %2 \n\t"
"swpne %1, %2,[%3] \n\t"
"bne 0b \n\t"
"ldr %1, 1f \n\t"
"bx %1 \n"
"1:\t"
".word 2f \n\t"
".code 16 \n"
"2:\n"
: "=&l"(__tmp), "=&r"(__tmp2), "=&r"(__tmp3)
: "r" (__mem), "r"(__val)
: "cc", "memory");
#else
__asm__ __volatile__ (
"\n"
"0:\t"
"ldr %0, [%3] \n\t"
"add %1, %0, %4 \n\t"
"swp %2, %1, [%3] \n\t"
"cmp %0, %2 \n\t"
"swpne %1, %2, [%3] \n\t"
"bne 0b \n\t"
""
: "=&r"(__tmp), "=&r"(__tmp2), "=&r"(__tmp3)
: "r" (__mem), "r"(__val)
: "cc", "memory");
#endif
}
static inline long
__attribute__ ((__unused__))
__always_swap (volatile long *__p, long __newval)
{
long __result;
#ifdef __thumb__
long __tmp;
/* Since this function is inlined, we can't be sure of the alignment. */
__asm__ __volatile__ (
"ldr %0, 4f \n\t"
"bx %0 \n\t"
".align 0 \n"
"4:\t"
".word 0f \n\t"
".code 32\n"
"0:\t"
"swp %0, %3, [%2] \n\t"
"ldr %1, 1f \n\t"
"bx %1 \n"
"1:\t"
".word 2f \n\t"
".code 16 \n"
"2:\n"
: "=&l"(__result), "=&r"(__tmp)
: "r"(__p), "r"(__newval)
: "memory");
#else
__asm__ __volatile__ (
"\n\t"
"swp %0, %2, [%1] \n\t"
""
: "=&r"(__result)
: "r"(__p), "r"(__newval)
: "memory");
#endif
return __result;
}
static inline int
__attribute__ ((__unused__))
__test_and_set (volatile long *__p, long __newval)
{
int __result;
long __tmp;
#ifdef __thumb__
/* Since this function is inlined, we can't be sure of the alignment. */
__asm__ __volatile__ (
"ldr %0, 4f \n\t"
"bx %0 \n\t"
".align 0 \n"
"4:\t"
".word 0f \n\t"
".code 32 \n"
"0:\t"
"ldr %0, [%2] \n\t"
"cmp %0, #0 \n\t"
"bne 1f \n\t"
"swp %1, %3, [%2] \n\t"
"cmp %0, %1 \n\t"
"swpne %0, %1, [%2]\n\t"
"bne 0b \n"
"1:\t"
"ldr %1, 2f \n\t"
"bx %1 \n"
"2:\t"
".word 3f \n\t"
".code 16 \n"
"3:"
: "=&l"(__result), "=r" (__tmp)
: "r"(__p), "r"(__newval)
: "cc", "memory");
#else
__asm__ __volatile__ (
"\n"
"0:\t"
"ldr %0, [%2] \n\t"
"cmp %0, #0 \n\t"
"bne 1f \n\t"
"swp %1, %3, [%2] \n\t"
"cmp %0, %1 \n\t"
"swpne %0, %1, [%2] \n\t"
"bne 0b \n"
"1:\n\t"
""
: "=&r"(__result), "=r" (__tmp)
: "r"(__p), "r"(__newval)
: "cc", "memory");
#endif
return __result;
}
#endif /* atomicity.h */
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