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@mansr.com>
This commit is contained in:
Mans Rullgard 2011-12-12 01:33:17 +00:00
parent f64c2e710f
commit 5b0d35eaed
2 changed files with 0 additions and 10 deletions

3
configure vendored
View File

@ -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"

View File

@ -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;
}