13% faster on penryn, 16% on sandybridge, 15% on bulldozer
Not simd; a compiler should have generated this, but gcc didn't.

GCC 4.3 and later do the right thing with the plain C code.  Earlier
versions in 32-bit mode generate one extra instruction, needlessly
zeroing what would be the high half of the shifted value.  At least
two gcc configurations miscompile the inline asm in some situations.

In 64-bit mode, all gcc versions generate imul r64, r64 followed by
shr.  On Intel i7 and later, this imul is faster 32-bit mul.  On
older Intel and all AMD, it is slightly slower.  On Atom it is much
slower.

Considering where the FASTDIV macro is used, any overall negative
performance impact of this change should be negligible.  If anyone
cares, they should file a bug against gcc and get the instruction
selection fixed.
Signed-off-by: Mans Rullgard <mans@mansr.com>

Signed-off-by: Martin Storsjö <martin@martin.st>

Signed-off-by: Martin Storsjö <martin@martin.st>

These x86-specific macros do not belong in generic code.
Signed-off-by: Mans Rullgard <mans@mansr.com>

This puts x86-specific things in the x86/ subdirectory where they
belong.
Signed-off-by: Mans Rullgard <mans@mansr.com>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

It appears that something goes wrong in old nasm versions when the
%+ operator is used in the last argument of a macro invocation and
this argument is tested with %ifdef within the macro.  This patch
rearranges the macro arguments such that the %+ operator is never
used in the last argument.

nasm does not support 'CPU foonop' directives.  This adds a configure
test for the directive and uses it only if supported.
Signed-off-by: Mans Rullgard <mans@mansr.com>

For some reason, nasm requires this.  No harm done to yasm.
Signed-off-by: Mans Rullgard <mans@mansr.com>

nasm prints a warning if the colon is missing.
Signed-off-by: Mans Rullgard <mans@mansr.com>

Refactoring mmx2/mmxext YASM code with cpuflags will force renames.
So switching to a consistent naming scheme beforehand is sensible.
The name "mmxext" is more official and widespread and also the name
of the CPU flag, as reported e.g. by the Linux kernel.

Currently there is a wild mix of 3dn2/3dnow2/3dnowext.  Switching to
"3dnowext", which is a more common name of the CPU flag, as reported
e.g. by the Linux kernel, unifies this.

This allows us to unconditionally set the cglobal num_args
parameter to a bigger value, thus making writing yasm code
even easier than before.
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

Simplifies pshufb masks that operate on words.

This adds macros for accessing the EFLAGS register and uses
these instead of coding the entire check in inline asm.
Signed-off-by: Mans Rullgard <mans@mansr.com>

Signed-off-by: Diego Biurrun <diego@biurrun.de>
Signed-off-by: Martin Storsjö <martin@martin.st>

Signed-off-by: Martin Storsjö <martin@martin.st>

Signed-off-by: Martin Storsjö <martin@martin.st>

This should fix the NASM box.
Reviewed-by: Michael Niedermayer <michaelni@gmx.at>

based on similar amdnop usage in ffmpeg
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Diego Biurrun <diego@biurrun.de>

Signed-off-by: Diego Biurrun <diego@biurrun.de>

This adds macros for accessing the EFLAGS register and uses
these instead of coding the entire check in inline asm.
Signed-off-by: Mans Rullgard <mans@mansr.com>

Fixes Ticket1466
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

This adds whitespace around operators, aligns line continuation
backslashes, and breaks long lines.  Also fixes an ifdef halfway
through a statement.  The one line of duplication this saved is
not worth the ugliness.
Signed-off-by: Mans Rullgard <mans@mansr.com>

Signed-off-by: Mans Rullgard <mans@mansr.com>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

The attribution was removed by libav while moving the code to libavutil

The original code is from
commit eb4825b5
Author: Loren Merritt <lorenm@u.washington.edu>
Date:   Thu Aug 10 19:06:25 2006 +0000

    sse and 3dnow implementations of float->int conversion and mdct windowing.
    15% faster vorbis.

and

commit 06972056
Author: Loren Merritt <lorenm@u.washington.edu>
Date:   Fri Aug 11 18:19:37 2006 +0000

    vorbis simd tweaks
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>