1 files changed, 83 insertions, 0 deletions
diff --git a/src/third-party/base64/lib/arch/avx2/enc_reshuffle.c b/src/third-party/base64/lib/arch/avx2/enc_reshuffle.c
new file mode 100644
index 0000000..ba16690
--- /dev/null
+++ b/src/third-party/base64/lib/arch/avx2/enc_reshuffle.c
@@ -0,0 +1,83 @@
+static inline __m256i
+enc_reshuffle (const __m256i input)
+{
+	// Translation of the SSSE3 reshuffling algorithm to AVX2. This one
+	// works with shifted (4 bytes) input in order to be able to work
+	// efficiently in the two 128-bit lanes.
+
+	// Input, bytes MSB to LSB:
+	// 0 0 0 0 x w v u t s r q p o n m
+	// l k j i h g f e d c b a 0 0 0 0
+
+	const __m256i in = _mm256_shuffle_epi8(input, _mm256_set_epi8(
+		10, 11,  9, 10,
+		 7,  8,  6,  7,
+		 4,  5,  3,  4,
+		 1,  2,  0,  1,
+
+		14, 15, 13, 14,
+		11, 12, 10, 11,
+		 8,  9,  7,  8,
+		 5,  6,  4,  5));
+	// in, bytes MSB to LSB:
+	// w x v w
+	// t u s t
+	// q r p q
+	// n o m n
+	// k l j k
+	// h i g h
+	// e f d e
+	// b c a b
+
+	const __m256i t0 = _mm256_and_si256(in, _mm256_set1_epi32(0x0FC0FC00));
+	// bits, upper case are most significant bits, lower case are least
+	// significant bits.
+	// 0000wwww XX000000 VVVVVV00 00000000
+	// 0000tttt UU000000 SSSSSS00 00000000
+	// 0000qqqq RR000000 PPPPPP00 00000000
+	// 0000nnnn OO000000 MMMMMM00 00000000
+	// 0000kkkk LL000000 JJJJJJ00 00000000
+	// 0000hhhh II000000 GGGGGG00 00000000
+	// 0000eeee FF000000 DDDDDD00 00000000
+	// 0000bbbb CC000000 AAAAAA00 00000000
+
+	const __m256i t1 = _mm256_mulhi_epu16(t0, _mm256_set1_epi32(0x04000040));
+	// 00000000 00wwwwXX 00000000 00VVVVVV
+	// 00000000 00ttttUU 00000000 00SSSSSS
+	// 00000000 00qqqqRR 00000000 00PPPPPP
+	// 00000000 00nnnnOO 00000000 00MMMMMM
+	// 00000000 00kkkkLL 00000000 00JJJJJJ
+	// 00000000 00hhhhII 00000000 00GGGGGG
+	// 00000000 00eeeeFF 00000000 00DDDDDD
+	// 00000000 00bbbbCC 00000000 00AAAAAA
+
+	const __m256i t2 = _mm256_and_si256(in, _mm256_set1_epi32(0x003F03F0));
+	// 00000000 00xxxxxx 000000vv WWWW0000
+	// 00000000 00uuuuuu 000000ss TTTT0000
+	// 00000000 00rrrrrr 000000pp QQQQ0000
+	// 00000000 00oooooo 000000mm NNNN0000
+	// 00000000 00llllll 000000jj KKKK0000
+	// 00000000 00iiiiii 000000gg HHHH0000
+	// 00000000 00ffffff 000000dd EEEE0000
+	// 00000000 00cccccc 000000aa BBBB0000
+
+	const __m256i t3 = _mm256_mullo_epi16(t2, _mm256_set1_epi32(0x01000010));
+	// 00xxxxxx 00000000 00vvWWWW 00000000
+	// 00uuuuuu 00000000 00ssTTTT 00000000
+	// 00rrrrrr 00000000 00ppQQQQ 00000000
+	// 00oooooo 00000000 00mmNNNN 00000000
+	// 00llllll 00000000 00jjKKKK 00000000
+	// 00iiiiii 00000000 00ggHHHH 00000000
+	// 00ffffff 00000000 00ddEEEE 00000000
+	// 00cccccc 00000000 00aaBBBB 00000000
+
+	return _mm256_or_si256(t1, t3);
+	// 00xxxxxx 00wwwwXX 00vvWWWW 00VVVVVV
+	// 00uuuuuu 00ttttUU 00ssTTTT 00SSSSSS
+	// 00rrrrrr 00qqqqRR 00ppQQQQ 00PPPPPP
+	// 00oooooo 00nnnnOO 00mmNNNN 00MMMMMM
+	// 00llllll 00kkkkLL 00jjKKKK 00JJJJJJ
+	// 00iiiiii 00hhhhII 00ggHHHH 00GGGGGG
+	// 00ffffff 00eeeeFF 00ddEEEE 00DDDDDD
+	// 00cccccc 00bbbbCC 00aaBBBB 00AAAAAA
+}