[FFmpeg-cvslog] x86: bswap: remove test for bswap instruction
Mans Rullgard
git at videolan.org
Tue Dec 13 00:59:44 CET 2011
ffmpeg | branch: master | Mans Rullgard <mans at mansr.com> | Mon Dec 12 01:33:17 2011 +0000| [5b0d35eaedbb08d0c11fa4f2b47a24d91aaa294d] | committer: Mans Rullgard
x86: bswap: remove test for bswap instruction
Firstly, this test never worked as intended, always reporting
success. Secondly, bswap is available from 486 onward and can
thus be assumed present.
Signed-off-by: Mans Rullgard <mans at mansr.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=5b0d35eaedbb08d0c11fa4f2b47a24d91aaa294d
---
configure | 3 ---
libavutil/x86/bswap.h | 7 -------
2 files changed, 0 insertions(+), 10 deletions(-)
diff --git a/configure b/configure
index a0dc6e0..567fa9d 100755
--- a/configure
+++ b/configure
@@ -1053,7 +1053,6 @@ HAVE_LIST="
asm_mod_y
attribute_may_alias
attribute_packed
- bswap
closesocket
cmov
dcbzl
@@ -2741,8 +2740,6 @@ EOF
enabled ssse3 && check_asm ssse3 '"pabsw %xmm0, %xmm0"'
enabled mmx2 && check_asm mmx2 '"pmaxub %mm0, %mm1"'
- check_asm bswap '"bswap %%eax" ::: "%eax"'
-
if ! disabled_any asm mmx yasm; then
if check_cmd $yasmexe --version; then
enabled x86_64 && yasm_extra="-m amd64"
diff --git a/libavutil/x86/bswap.h b/libavutil/x86/bswap.h
index 6840b63..c6cf007 100644
--- a/libavutil/x86/bswap.h
+++ b/libavutil/x86/bswap.h
@@ -41,14 +41,7 @@ static av_always_inline av_const unsigned av_bswap16(unsigned x)
#define av_bswap32 av_bswap32
static av_always_inline av_const uint32_t av_bswap32(uint32_t x)
{
-#if HAVE_BSWAP
__asm__("bswap %0" : "+r" (x));
-#else
- __asm__("rorw $8, %w0 \n\t"
- "rorl $16, %0 \n\t"
- "rorw $8, %w0"
- : "+r"(x));
-#endif
return x;
}
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