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x86/tx_float: mark AVX2 functions as AVXSLOW 

Makes Bulldozer prefer AVX functions rather than AVX2,
which are 64% slower:

AVX:  117653 decicycles in av_tx (fft), 1048535 runs,     41 skips
AVX2: 193385 decicycles in av_tx (fft), 1048561 runs,     15 skips

The only difference between both is that vgatherdpd is used in
the former. We don't want to mark them with the new SLOW_GATHER
flag however, since gathers are still faster on Haswell/Zen 2/3
than plain loads.
This commit is contained in:
Lynne 2022-01-29 03:08:16 +01:00
parent 7e35e0224c
commit 35080149ef
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GPG Key ID: A2FEA5F03F034464
1 changed files with 2 additions and 2 deletions
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4
libavutil/x86/tx_float_init.c
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@ -100,11 +100,11 @@ DECL_CD_DEF(fft_sr_ns_float_avx, FFT, 64, 131072, 2, 0, fft_sr_codelet_init_b8_i
#if HAVE_AVX2_EXTERNAL
DECL_CD_DEF(fft_sr_float_avx2, FFT, 64, 131072, 2, 0, fft_sr_codelet_init_b8_i2,
288, AV_CPU_FLAG_AVX2,
288, AV_CPU_FLAG_AVX2 | AV_CPU_FLAG_AVXSLOW,
FF_TX_OUT_OF_PLACE)
DECL_CD_DEF(fft_sr_ns_float_avx2, FFT, 64, 131072, 2, 0, fft_sr_codelet_init_b8_i2,
352, AV_CPU_FLAG_AVX2,
352, AV_CPU_FLAG_AVX2 | AV_CPU_FLAG_AVXSLOW,
FF_TX_OUT_OF_PLACE | AV_TX_INPLACE | FF_TX_PRESHUFFLE)
#endif
#endif