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102 lines
3.7 KiB
C
102 lines
3.7 KiB
C
/* Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#include <stdint.h>
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#include <sysdep.h>
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typedef int8_t atomic8_t;
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typedef uint8_t uatomic8_t;
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typedef int_fast8_t atomic_fast8_t;
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typedef uint_fast8_t uatomic_fast8_t;
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typedef int32_t atomic32_t;
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typedef uint32_t uatomic32_t;
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typedef int_fast32_t atomic_fast32_t;
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typedef uint_fast32_t uatomic_fast32_t;
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typedef intptr_t atomicptr_t;
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typedef uintptr_t uatomicptr_t;
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typedef intmax_t atomic_max_t;
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typedef uintmax_t uatomic_max_t;
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void __arm_link_error (void);
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#define atomic_exchange_acq(mem, newvalue) \
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({ __typeof (*mem) result; \
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if (sizeof (*mem) == 1) \
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__asm__ __volatile__ ("swpb %0, %1, [%2]" \
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: "=&r,&r" (result) \
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: "r,0" (newvalue), "r,r" (mem) : "memory"); \
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else if (sizeof (*mem) == 4) \
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__asm__ __volatile__ ("swp %0, %1, [%2]" \
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: "=&r,&r" (result) \
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: "r,0" (newvalue), "r,r" (mem) : "memory"); \
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else \
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{ \
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result = 0; \
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abort (); \
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} \
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result; })
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/* Atomic compare and exchange. These sequences are not actually atomic;
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there is a race if *MEM != OLDVAL and we are preempted between the two
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swaps. However, they are very close to atomic, and are the best that a
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pre-ARMv6 implementation can do without operating system support.
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LinuxThreads has been using these sequences for many years. */
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#define __arch_compare_and_exchange_val_8_acq(mem, newval, oldval) \
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({ __typeof (oldval) result, tmp; \
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__asm__ ("\n" \
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"0:\tldr\t%1,[%2]\n\t" \
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"cmp\t%1,%4\n\t" \
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"movne\t%0,%1\n\t" \
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"bne\t1f\n\t" \
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"swpb\t%0,%3,[%2]\n\t" \
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"cmp\t%1,%0\n\t" \
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"swpbne\t%1,%0,[%2]\n\t" \
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"bne\t0b\n\t" \
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"1:" \
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: "=&r" (result), "=&r" (tmp) \
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: "r" (mem), "r" (newval), "r" (oldval) \
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: "cc", "memory"); \
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result; })
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#define __arch_compare_and_exchange_val_16_acq(mem, newval, oldval) \
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({ __arm_link_error (); oldval; })
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#define __arch_compare_and_exchange_val_32_acq(mem, newval, oldval) \
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({ __typeof (oldval) result, tmp; \
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__asm__ ("\n" \
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"0:\tldr\t%1,[%2]\n\t" \
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"cmp\t%1,%4\n\t" \
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"movne\t%0,%1\n\t" \
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"bne\t1f\n\t" \
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"swp\t%0,%3,[%2]\n\t" \
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"cmp\t%1,%0\n\t" \
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"swpne\t%1,%0,[%2]\n\t" \
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"bne\t0b\n\t" \
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"1:" \
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: "=&r" (result), "=&r" (tmp) \
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: "r" (mem), "r" (newval), "r" (oldval) \
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: "cc", "memory"); \
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result; })
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#define __arch_compare_and_exchange_val_64_acq(mem, newval, oldval) \
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({ __arm_link_error (); oldval; })
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