1. Only for fixed point on x86 platform (32bit and 64bit, uses SIMD
intrinsics up to SSE4.2)
2. Use "configure --enable-fixed-point --enable-intrinsics" to enable
optimization, default is disabled.
3. Official test cases are verified and passed.
Signed-off-by: Timothy B. Terriberry <tterribe@xiph.org>
This reduces the peak decoding error by removing small (inaudible) spikes in
the error at the frame boundaries. These were due to the frequency-domain bias
ending up as a small pulse in the middle of the IMDCT overlap. None of this
was ever audible, but fixing it is still cleaner.
We had previously advised people to -Drestrict on
non-C99 compilers, but this creates problems for
some of the MSVC headers. Instead this just
uses a macro and defines it sanely.
