On Sun, Dec 20, 2015 at 01:30:57PM +0300, lvqcl wrote: > Erik de Castro Lopo wrote: > > > The think in and ideal world we would a: > > > > * Make it work correctly FLAC__BYTES_PER_WORD == 8 and compare the > > performance > > with FLAC__BYTES_PER_WORD == 4. > > * If there is an statistically measurable performance, keep it, otherwise > > remove the FLAC__BYTES_PER_WORD == 8 code all together. > > I'll try to do it, but I don't have a deep understanding of bit(read|write) > routines such as FLAC__bitreader_read_rice_signed_block() and other. > Maybe Miroslav Lichvar can say something?
Using larger registers in the bitreader/bitwriter should reduce the number of instructions needed when reading/writing the encoded stream as fewer words need to be read/written and encoded values are less likely to be split across two words. In the measurements comparing 32-bit and 64-bit words you posted later, I'm wondering why there is a slow down in decoding of 24-bit files. Does profiling show it comes from the read_rice_signed_block() function or something else? Could it be slower SWAP_BE_WORD_TO_HOST or COUNT_ZERO_MSBS2? -- Miroslav Lichvar _______________________________________________ flac-dev mailing list flac-dev@xiph.org http://lists.xiph.org/mailman/listinfo/flac-dev
