[FFmpeg-cvslog] bswap: use native types for av_bwap16().

[Jason Garrett-Glaser]

ffmpeg | branch: master | Jason Garrett-Glaser <jason at x264.com> | Fri Apr 22 17:59:55 2011 -0400| [15919ee48f507a4ca17147e7247f5cb68f752c2c] | committer: Ronald S. Bultje

bswap: use native types for av_bwap16().

This prevents a call to bytestream_get_be16() using a movzwl both before
and after the ror instruction, which is obviously inefficient. Arm uses
the same trick also.

Sintel decoding goes from (avg+SD) 9.856 +/- 0.003 to 9.797 +/- 0.003 sec.

Signed-off-by: Ronald S. Bultje <rsbultje at gmail.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=15919ee48f507a4ca17147e7247f5cb68f752c2c
---

 libavutil/x86/bswap.h |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavutil/x86/bswap.h b/libavutil/x86/bswap.h
index 28e3fec..b60d9cc 100644
--- a/libavutil/x86/bswap.h
+++ b/libavutil/x86/bswap.h
@@ -29,9 +29,9 @@
 #include "libavutil/attributes.h"
 
 #define av_bswap16 av_bswap16
-static av_always_inline av_const uint16_t av_bswap16(uint16_t x)
+static av_always_inline av_const unsigned av_bswap16(unsigned x)
 {
-    __asm__("rorw $8, %0" : "+r"(x));
+    __asm__("rorw $8, %w0" : "+r"(x));
     return x;
 }