[flac-dev] PATCH for lpc_intrin_sse41.c: faster shifts
lvqcl.mail at gmail.com
Fri Jan 24 10:57:46 PST 2014
It turns out that int64 shift is quite slow...
This patch changes the code from:
(FLAC__int32)(xmm.m128i_i64 >> lp_quantization)
Encoding of 24-bit .wav files with 32-bit FLAC became noticeably faster.
The new code works only if quantization <= 32, but its max value is 15 so the code always work.
(max_shiftlimit == (1 << (FLAC__SUBFRAME_LPC_QLP_SHIFT_LEN-1)) - 1 == 15)
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