1 files changed, 57 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/i386/bits/atomicity.h b/libc/sysdeps/linux/i386/bits/atomicity.h
new file mode 100644
index 000000000..df2fb8184
--- /dev/null
+++ b/libc/sysdeps/linux/i386/bits/atomicity.h
@@ -0,0 +1,57 @@
+/* Low-level functions for atomic operations.  ix86 version, x >= 4.
+   Copyright (C) 1997, 2000, 2001 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#ifndef _ATOMICITY_H
+#define _ATOMICITY_H	1
+
+#include <inttypes.h>
+
+
+static inline uint32_t
+__attribute__ ((unused))
+exchange_and_add (volatile uint32_t *mem, uint32_t val)
+{
+  register uint32_t result;
+  __asm__ __volatile__ ("lock; xaddl %0,%1"
+			: "=r" (result), "=m" (*mem) : "0" (val), "1" (*mem));
+  return result;
+}
+
+static inline void
+__attribute__ ((unused))
+atomic_add (volatile uint32_t *mem, int val)
+{
+  __asm__ __volatile__ ("lock; addl %1,%0"
+			: "=m" (*mem) : "ir" (val), "0" (*mem));
+}
+
+static inline char
+__attribute__ ((unused))
+compare_and_swap (volatile long int *p, long int oldval, long int newval)
+{
+  char ret;
+  long int readval;
+
+  __asm__ __volatile__ ("lock; cmpxchgl %3, %1; sete %0"
+                        : "=q" (ret), "=m" (*p), "=a" (readval)
+                        : "r" (newval), "1" (*p), "a" (oldval));
+  return ret;
+}
+
+#endif /* atomicity.h */