Re: [PATCH] cpu.h: add defines for clang
lvqcl <[email protected]>
| Newsgroups | gmane.comp.audio.compression.flac.devel |
|---|---|
| Message-ID | <op.yvjosfr9cba0by@userme-pc> |
Erik de Castro Lopo wrote: > How reliable a test is that? I do 99.9% of my dev work on a laptop > and whenever I need to benchmark something I need to do so on a > desketop machine because the laptop doesn't give consistent results. About 1.5 years ago I tested AVX2 speed increase on Haswell (i7-4770) using -8 encoding preset. The biggest difference between AVX2 enabled and disabled was 35% (64-bit flac.exe, 24-bit WAV input file). The smallest difference was 10% (32-bit flac.exe, 16-bit WAV input file). > Disassembly of the object files (before and after) is here: > > http://mega-nerd.com/tmp/stream_encoder_intrin_avx2-before.txt > http://mega-nerd.com/tmp/stream_encoder_intrin_avx2-after.txt > > This is with clang version 3.8.1 from Debian testing. I forgot that all avx2 functions are inside "#ifdef FLAC__AVX2_SUPPORTED" conditional, so they simply don't exist if FLAC__AVX2_SUPPORTED is not set. Anyway, stream_encoder_intrin_avx2-after.txt shows that the code contains AVX2 instructions such as vpabsd/vpaddd/vphaddd, so this function was compiled properly. _______________________________________________ flac-dev mailing list [email protected] http://lists.xiph.org/mailman/listinfo/flac-dev