--- /dev/null
+/* Linux-specific atomic operations for m68k Linux.
+ Copyright (C) 2011 Free Software Foundation, Inc.
+ Based on code contributed by CodeSourcery for ARM EABI Linux.
+
+This file is part of GCC.
+
+GCC 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.
+
+GCC 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/>. */
+
+/* Coldfire dropped the CAS instruction from the base M68K ISA.
+
+ GCC automatically issues a asm memory barrier when it encounters
+ a __sync_synchronize builtin. Thus, we do not need to define this
+ builtin.
+
+ We implement byte, short and int versions of each atomic operation
+ using the kernel helper defined below. There is no support for
+ 64-bit operations yet. */
+
+#include <asm/unistd.h>
+#include <stdbool.h>
+
+#ifndef __NR_atomic_cmpxchg_32
+#define __NR_atomic_cmpxchg_32 335
+#endif
+
+/* Kernel helper for compare-and-exchange a 32-bit value. */
+static inline unsigned
+__kernel_cmpxchg (unsigned *mem, unsigned oldval, unsigned newval)
+{
+ register unsigned *a0 asm("a0") = mem;
+ register unsigned d2 asm("d2") = oldval;
+ register unsigned d1 asm("d1") = newval;
+ register unsigned d0 asm("d0") = __NR_atomic_cmpxchg_32;
+
+ asm volatile ("trap #0"
+ : "=r"(d0), "=r"(d1), "=r"(a0)
+ : "r"(d0), "r"(d1), "r"(d2), "r"(a0)
+ : "memory", "a1");
+
+ return d0;
+}
+
+#define HIDDEN __attribute__ ((visibility ("hidden")))
+
+/* Big endian masks */
+#define INVERT_MASK_1 24
+#define INVERT_MASK_2 16
+
+#define MASK_1 0xffu
+#define MASK_2 0xffffu
+
+#define NAME_oldval(OP, WIDTH) __sync_fetch_and_##OP##_##WIDTH
+#define NAME_newval(OP, WIDTH) __sync_##OP##_and_fetch_##WIDTH
+
+#define WORD_SYNC_OP(OP, PFX_OP, INF_OP, RETURN) \
+ unsigned HIDDEN \
+ NAME##_##RETURN (OP, 4) (unsigned *ptr, unsigned val) \
+ { \
+ unsigned oldval, newval, cmpval = *ptr; \
+ \
+ do { \
+ oldval = cmpval; \
+ newval = PFX_OP (oldval INF_OP val); \
+ cmpval = __kernel_cmpxchg (ptr, oldval, newval); \
+ } while (__builtin_expect (oldval != cmpval, 0)); \
+ \
+ return RETURN; \
+ }
+
+#define SUBWORD_SYNC_OP(OP, PFX_OP, INF_OP, TYPE, WIDTH, RETURN) \
+ TYPE HIDDEN \
+ NAME##_##RETURN (OP, WIDTH) (TYPE *ptr, TYPE sval) \
+ { \
+ unsigned *wordptr = (unsigned *) ((unsigned long) ptr & ~3); \
+ unsigned int mask, shift, oldval, newval, cmpval, wval; \
+ \
+ shift = (((unsigned long) ptr & 3) << 3) ^ INVERT_MASK_##WIDTH; \
+ mask = MASK_##WIDTH << shift; \
+ wval = (sval & MASK_##WIDTH) << shift; \
+ \
+ cmpval = *wordptr; \
+ do { \
+ oldval = cmpval; \
+ newval = PFX_OP (oldval INF_OP wval); \
+ newval = (newval & mask) | (oldval & ~mask); \
+ cmpval = __kernel_cmpxchg (wordptr, oldval, newval); \
+ } while (__builtin_expect (oldval != cmpval, 0)); \
+ \
+ return (RETURN >> shift) & MASK_##WIDTH; \
+ }
+
+WORD_SYNC_OP (add, , +, oldval)
+WORD_SYNC_OP (sub, , -, oldval)
+WORD_SYNC_OP (or, , |, oldval)
+WORD_SYNC_OP (and, , &, oldval)
+WORD_SYNC_OP (xor, , ^, oldval)
+WORD_SYNC_OP (nand, ~, &, oldval)
+
+SUBWORD_SYNC_OP (add, , +, unsigned short, 2, oldval)
+SUBWORD_SYNC_OP (sub, , -, unsigned short, 2, oldval)
+SUBWORD_SYNC_OP (or, , |, unsigned short, 2, oldval)
+SUBWORD_SYNC_OP (and, , &, unsigned short, 2, oldval)
+SUBWORD_SYNC_OP (xor, , ^, unsigned short, 2, oldval)
+SUBWORD_SYNC_OP (nand, ~, &, unsigned short, 2, oldval)
+
+SUBWORD_SYNC_OP (add, , +, unsigned char, 1, oldval)
+SUBWORD_SYNC_OP (sub, , -, unsigned char, 1, oldval)
+SUBWORD_SYNC_OP (or, , |, unsigned char, 1, oldval)
+SUBWORD_SYNC_OP (and, , &, unsigned char, 1, oldval)
+SUBWORD_SYNC_OP (xor, , ^, unsigned char, 1, oldval)
+SUBWORD_SYNC_OP (nand, ~, &, unsigned char, 1, oldval)
+
+WORD_SYNC_OP (add, , +, newval)
+WORD_SYNC_OP (sub, , -, newval)
+WORD_SYNC_OP (or, , |, newval)
+WORD_SYNC_OP (and, , &, newval)
+WORD_SYNC_OP (xor, , ^, newval)
+WORD_SYNC_OP (nand, ~, &, newval)
+
+SUBWORD_SYNC_OP (add, , +, unsigned short, 2, newval)
+SUBWORD_SYNC_OP (sub, , -, unsigned short, 2, newval)
+SUBWORD_SYNC_OP (or, , |, unsigned short, 2, newval)
+SUBWORD_SYNC_OP (and, , &, unsigned short, 2, newval)
+SUBWORD_SYNC_OP (xor, , ^, unsigned short, 2, newval)
+SUBWORD_SYNC_OP (nand, ~, &, unsigned short, 2, newval)
+
+SUBWORD_SYNC_OP (add, , +, unsigned char, 1, newval)
+SUBWORD_SYNC_OP (sub, , -, unsigned char, 1, newval)
+SUBWORD_SYNC_OP (or, , |, unsigned char, 1, newval)
+SUBWORD_SYNC_OP (and, , &, unsigned char, 1, newval)
+SUBWORD_SYNC_OP (xor, , ^, unsigned char, 1, newval)
+SUBWORD_SYNC_OP (nand, ~, &, unsigned char, 1, newval)
+
+unsigned HIDDEN
+__sync_val_compare_and_swap_4 (unsigned *ptr, unsigned oldval, unsigned newval)
+{
+ return __kernel_cmpxchg (ptr, oldval, newval);
+}
+
+bool HIDDEN
+__sync_bool_compare_and_swap_4 (unsigned *ptr, unsigned oldval,
+ unsigned newval)
+{
+ return __kernel_cmpxchg (ptr, oldval, newval) == oldval;
+}
+
+#define SUBWORD_VAL_CAS(TYPE, WIDTH) \
+ TYPE HIDDEN \
+ __sync_val_compare_and_swap_##WIDTH (TYPE *ptr, TYPE soldval, \
+ TYPE snewval) \
+ { \
+ unsigned *wordptr = (unsigned *)((unsigned long) ptr & ~3); \
+ unsigned int mask, shift, woldval, wnewval; \
+ unsigned oldval, newval, cmpval; \
+ \
+ shift = (((unsigned long) ptr & 3) << 3) ^ INVERT_MASK_##WIDTH; \
+ mask = MASK_##WIDTH << shift; \
+ woldval = (soldval & MASK_##WIDTH) << shift; \
+ wnewval = (snewval & MASK_##WIDTH) << shift; \
+ cmpval = *wordptr; \
+ \
+ do { \
+ oldval = cmpval; \
+ if ((oldval & mask) != woldval) \
+ break; \
+ newval = (oldval & ~mask) | wnewval; \
+ cmpval = __kernel_cmpxchg (wordptr, oldval, newval); \
+ } while (__builtin_expect (oldval != cmpval, 0)); \
+ \
+ return (oldval >> shift) & MASK_##WIDTH; \
+ }
+
+SUBWORD_VAL_CAS (unsigned short, 2)
+SUBWORD_VAL_CAS (unsigned char, 1)
+
+#define SUBWORD_BOOL_CAS(TYPE, WIDTH) \
+ bool HIDDEN \
+ __sync_bool_compare_and_swap_##WIDTH (TYPE *ptr, TYPE oldval, \
+ TYPE newval) \
+ { \
+ return (__sync_val_compare_and_swap_##WIDTH (ptr, oldval, newval) \
+ == oldval); \
+ }
+
+SUBWORD_BOOL_CAS (unsigned short, 2)
+SUBWORD_BOOL_CAS (unsigned char, 1)
+
+#undef NAME_oldval
+#define NAME_oldval(OP, WIDTH) __sync_lock_##OP##_##WIDTH
+#define COMMA ,
+
+WORD_SYNC_OP (test_and_set, , COMMA, oldval)
+SUBWORD_SYNC_OP (test_and_set, , COMMA, unsigned short, 1, oldval)
+SUBWORD_SYNC_OP (test_and_set, , COMMA, unsigned short, 2, oldval)
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