From 15ceee3a7c72d174305fff9b4fe9886cb3f7204d Mon Sep 17 00:00:00 2001 From: Sebastiano Tronto Date: Sun, 19 Nov 2023 10:45:37 +0100 Subject: Removed inverse_fast, probably not going to use it in tight loops --- old/inverse_fast.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 old/inverse_fast.c (limited to 'old') diff --git a/old/inverse_fast.c b/old/inverse_fast.c new file mode 100644 index 0000000..13ace58 --- /dev/null +++ b/old/inverse_fast.c @@ -0,0 +1,51 @@ +_static_inline cube_fast_t +cleanaftershuffle(cube_fast_t c) +{ + __m256i b; + + b = _mm256_set_epi8( + ~0, ~0, ~0, ~0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + ~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0, 0, 0, 0, 0, 0, 0, 0, 0 + ); + + return _mm256_andnot_si256(b, c); +} + +_static_inline cube_fast_t +inverse_fast(cube_fast_t c) +{ + /* Method taken from Andrew Skalski's vcube[1]. The addition sequence + * was generated using [2]. + * [1] https://github.com/Voltara/vcube + * [2] http://wwwhomes.uni-bielefeld.de/achim/addition_chain.html + */ + cube_fast_t v3, vi, vo, vp, ret; + + v3 = _mm256_shuffle_epi8(c, c); + v3 = _mm256_shuffle_epi8(v3, c); + vi = _mm256_shuffle_epi8(v3, v3); + vi = _mm256_shuffle_epi8(vi, vi); + vi = _mm256_shuffle_epi8(vi, vi); + vi = _mm256_shuffle_epi8(vi, v3); + vi = _mm256_shuffle_epi8(vi, vi); + vi = _mm256_shuffle_epi8(vi, vi); + vi = _mm256_shuffle_epi8(vi, vi); + vi = _mm256_shuffle_epi8(vi, vi); + vi = _mm256_shuffle_epi8(vi, c); + vi = _mm256_shuffle_epi8(vi, vi); + vi = _mm256_shuffle_epi8(vi, vi); + vi = _mm256_shuffle_epi8(vi, vi); + vi = _mm256_shuffle_epi8(vi, vi); + vi = _mm256_shuffle_epi8(vi, vi); + vi = _mm256_shuffle_epi8(vi, v3); + vi = _mm256_shuffle_epi8(vi, vi); + vi = _mm256_shuffle_epi8(vi, c); + + vo = _mm256_and_si256(c, _mm256_or_si256(_eo_avx2, _co2_avx2)); + vo = _mm256_shuffle_epi8(vo, vi); + vp = _mm256_andnot_si256(_mm256_or_si256(_eo_avx2, _co2_avx2), vi); + ret = _mm256_or_si256(vp, vo); + ret = cleanaftershuffle(ret); + + return invertco_fast(ret); +} -- cgit v1.3