aarch64: bswap inline assembly

Signed-off-by: Janne Grunau <janne-libav@jannau.net>

libavutil/aarch64/bswap.h

+/*
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVUTIL_AARCH64_BSWAP_H
+#define AVUTIL_AARCH64_BSWAP_H
+
+#include <stdint.h>
+#include "config.h"
+#include "libavutil/attributes.h"
+
+#if HAVE_INLINE_ASM
+
+#define av_bswap16 av_bswap16
+static av_always_inline av_const unsigned av_bswap16(unsigned x)
+{
+    __asm__("rev16 %w0, %w0" : "+r"(x));
+    return x;
+}
+
+#define av_bswap32 av_bswap32
+static av_always_inline av_const uint32_t av_bswap32(uint32_t x)
+{
+    __asm__("rev %w0, %w0" : "+r"(x));
+    return x;
+}
+
+#define av_bswap64 av_bswap64
+static av_always_inline av_const uint64_t av_bswap64(uint64_t x)
+{
+    __asm__("rev %0, %0" : "+r"(x));
+    return x;
+}
+
+#endif /* HAVE_INLINE_ASM */
+#endif /* AVUTIL_AARCH64_BSWAP_H */

libavutil/bswap.h

@@ -34,7 +34,9 @@
 
 #include "config.h"
 
-#if   ARCH_ARM
+#if   ARCH_AARCH64
+#   include "aarch64/bswap.h"
+#elif ARCH_ARM
 #   include "arm/bswap.h"
 #elif ARCH_AVR32
 #   include "avr32/bswap.h"