From 5068d34c08f951a7ea6257d305a1627b09a95817 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 4 May 2024 19:44:55 +0200 Subject: Adding upstream version 0.11.1. Signed-off-by: Daniel Baumann --- src/third-party/base64/lib/arch/neon32/dec_loop.c | 106 ++++++++++++++++++++++ 1 file changed, 106 insertions(+) create mode 100644 src/third-party/base64/lib/arch/neon32/dec_loop.c (limited to 'src/third-party/base64/lib/arch/neon32/dec_loop.c') diff --git a/src/third-party/base64/lib/arch/neon32/dec_loop.c b/src/third-party/base64/lib/arch/neon32/dec_loop.c new file mode 100644 index 0000000..2216b39 --- /dev/null +++ b/src/third-party/base64/lib/arch/neon32/dec_loop.c @@ -0,0 +1,106 @@ +static inline int +is_nonzero (const uint8x16_t v) +{ + uint64_t u64; + const uint64x2_t v64 = vreinterpretq_u64_u8(v); + const uint32x2_t v32 = vqmovn_u64(v64); + + vst1_u64(&u64, vreinterpret_u64_u32(v32)); + return u64 != 0; +} + +static inline uint8x16_t +delta_lookup (const uint8x16_t v) +{ + const uint8x8_t lut = { + 0, 16, 19, 4, (uint8_t) -65, (uint8_t) -65, (uint8_t) -71, (uint8_t) -71, + }; + + return vcombine_u8( + vtbl1_u8(lut, vget_low_u8(v)), + vtbl1_u8(lut, vget_high_u8(v))); +} + +static inline uint8x16_t +dec_loop_neon32_lane (uint8x16_t *lane) +{ + // See the SSSE3 decoder for an explanation of the algorithm. + const uint8x16_t lut_lo = { + 0x15, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, + 0x11, 0x11, 0x13, 0x1A, 0x1B, 0x1B, 0x1B, 0x1A + }; + + const uint8x16_t lut_hi = { + 0x10, 0x10, 0x01, 0x02, 0x04, 0x08, 0x04, 0x08, + 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10 + }; + + const uint8x16_t mask_0F = vdupq_n_u8(0x0F); + const uint8x16_t mask_2F = vdupq_n_u8(0x2F); + + const uint8x16_t hi_nibbles = vshrq_n_u8(*lane, 4); + const uint8x16_t lo_nibbles = vandq_u8(*lane, mask_0F); + const uint8x16_t eq_2F = vceqq_u8(*lane, mask_2F); + + const uint8x16_t hi = vqtbl1q_u8(lut_hi, hi_nibbles); + const uint8x16_t lo = vqtbl1q_u8(lut_lo, lo_nibbles); + + // Now simply add the delta values to the input: + *lane = vaddq_u8(*lane, delta_lookup(vaddq_u8(eq_2F, hi_nibbles))); + + // Return the validity mask: + return vandq_u8(lo, hi); +} + +static inline void +dec_loop_neon32 (const uint8_t **s, size_t *slen, uint8_t **o, size_t *olen) +{ + if (*slen < 64) { + return; + } + + // Process blocks of 64 bytes per round. Unlike the SSE codecs, no + // extra trailing zero bytes are written, so it is not necessary to + // reserve extra input bytes: + size_t rounds = *slen / 64; + + *slen -= rounds * 64; // 64 bytes consumed per round + *olen += rounds * 48; // 48 bytes produced per round + + do { + uint8x16x3_t dec; + + // Load 64 bytes and deinterleave: + uint8x16x4_t str = vld4q_u8(*s); + + // Decode each lane, collect a mask of invalid inputs: + const uint8x16_t classified + = dec_loop_neon32_lane(&str.val[0]) + | dec_loop_neon32_lane(&str.val[1]) + | dec_loop_neon32_lane(&str.val[2]) + | dec_loop_neon32_lane(&str.val[3]); + + // Check for invalid input: if any of the delta values are + // zero, fall back on bytewise code to do error checking and + // reporting: + if (is_nonzero(classified)) { + break; + } + + // Compress four bytes into three: + dec.val[0] = vorrq_u8(vshlq_n_u8(str.val[0], 2), vshrq_n_u8(str.val[1], 4)); + dec.val[1] = vorrq_u8(vshlq_n_u8(str.val[1], 4), vshrq_n_u8(str.val[2], 2)); + dec.val[2] = vorrq_u8(vshlq_n_u8(str.val[2], 6), str.val[3]); + + // Interleave and store decoded result: + vst3q_u8(*o, dec); + + *s += 64; + *o += 48; + + } while (--rounds > 0); + + // Adjust for any rounds that were skipped: + *slen += rounds * 64; + *olen -= rounds * 48; +} -- cgit v1.2.3