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diff --git a/libc/sysdeps/linux/kvx/bits/atomic.h b/libc/sysdeps/linux/kvx/bits/atomic.h
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+/* Copyright (C) 2010-2012 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Maxim Kuvyrkov <maxim@codesourcery.com>, 2010.
+
+ 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, see
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef _KVX_BITS_ATOMIC_H
+#define _KVX_BITS_ATOMIC_H
+
+#include <stdint.h>
+
+typedef int8_t atomic8_t;
+typedef uint8_t uatomic8_t;
+typedef int_fast8_t atomic_fast8_t;
+typedef uint_fast8_t uatomic_fast8_t;
+
+typedef int16_t atomic16_t;
+typedef uint16_t uatomic16_t;
+typedef int_fast16_t atomic_fast16_t;
+typedef uint_fast16_t uatomic_fast16_t;
+
+typedef int32_t atomic32_t;
+typedef uint32_t uatomic32_t;
+typedef int_fast32_t atomic_fast32_t;
+typedef uint_fast32_t uatomic_fast32_t;
+
+typedef int64_t atomic64_t;
+typedef uint64_t uatomic64_t;
+typedef int_fast64_t atomic_fast64_t;
+typedef uint_fast64_t uatomic_fast64_t;
+
+typedef intptr_t atomicptr_t;
+typedef uintptr_t uatomicptr_t;
+typedef intmax_t atomic_max_t;
+typedef uintmax_t uatomic_max_t;
+
+
+#ifndef atomic_full_barrier
+# define atomic_full_barrier() do { atomic_read_barrier(); \
+ atomic_write_barrier(); } while(0)
+#endif
+
+#ifndef atomic_read_barrier
+# define atomic_read_barrier() __builtin_kvx_dinval()
+#endif
+
+#ifndef atomic_write_barrier
+# define atomic_write_barrier() __builtin_kvx_fence()
+#endif
+
+/*
+ * On kvx, we have a boolean compare and swap which means that the operation
+ * returns only the success of operation.
+ * If operation succeeds, this is simple, we just need to return the provided
+ * old value. However, if it fails, we need to load the value to return it for
+ * the caller. If the loaded value is different from the "old" provided by the
+ * caller, we can return it since it will mean it failed.
+ * However, if for some reason the value we read is equal to the old value
+ * provided by the caller, we can't simply return it or the caller will think it
+ * succeeded. So if the value we read is the same as the "old" provided by
+ * the caller, we try again until either we succeed or we fail with a different
+ * value than the provided one.
+ */
+#define __cmpxchg(ptr, old, new, op_suffix, load_suffix) \
+({ \
+ register unsigned long __rn __asm__("r62"); \
+ register unsigned long __ro __asm__("r63"); \
+ __asm__ __volatile__ ( \
+ /* Fence to guarantee previous store to be committed */ \
+ "fence\n" \
+ /* Init "expect" with previous value */ \
+ "copyd $r63 = %[rOld]\n" \
+ ";;\n" \
+ "1:\n" \
+ /* Init "update" value with new */ \
+ "copyd $r62 = %[rNew]\n" \
+ ";;\n" \
+ "acswap" #op_suffix " 0[%[rPtr]], $r62r63\n" \
+ ";;\n" \
+ /* if acswap succeeds, simply return */ \
+ "cb.dnez $r62? 2f\n" \
+ ";;\n" \
+ /* We failed, load old value */ \
+ "l" #op_suffix #load_suffix" $r63 = 0[%[rPtr]]\n" \
+ ";;\n" \
+ /* Check if equal to "old" one */ \
+ "compd.ne $r62 = $r63, %[rOld]\n" \
+ ";;\n" \
+ /* If different from "old", return it to caller */ \
+ "cb.deqz $r62? 1b\n" \
+ ";;\n" \
+ "2:\n" \
+ : "+r" (__rn), "+r" (__ro) \
+ : [rPtr] "r" (ptr), [rOld] "r" (old), [rNew] "r" (new) \
+ : "memory"); \
+ (__ro); \
+})
+
+#define cmpxchg(ptr, o, n) \
+({ \
+ unsigned long __cmpxchg__ret; \
+ switch (sizeof(*(ptr))) { \
+ case 4: \
+ __cmpxchg__ret = __cmpxchg((ptr), (o), (n), w, s); \
+ break; \
+ case 8: \
+ __cmpxchg__ret = __cmpxchg((ptr), (o), (n), d, ); \
+ break; \
+ } \
+ (__typeof(*(ptr))) (__cmpxchg__ret); \
+})
+
+#define atomic_compare_and_exchange_val_acq(mem, newval, oldval) \
+ cmpxchg((mem), (oldval), (newval))
+
+
+#define atomic_exchange_acq(mem, newval) \
+({ \
+ unsigned long __aea__ret, __aea__old; \
+ volatile __typeof((mem)) __aea__m = (mem); \
+ do { \
+ __aea__old = *__aea__m; \
+ __aea__ret = atomic_compare_and_exchange_val_acq((mem), \
+ (newval), (__aea__old));\
+ } while (__aea__old != __aea__ret); \
+ (__aea__old); \
+})
+
+#endif