diff options
Diffstat (limited to 'migration/xbzrle.c')
| -rw-r--r-- | migration/xbzrle.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/migration/xbzrle.c b/migration/xbzrle.c index 1ba482d..05366e8 100644 --- a/migration/xbzrle.c +++ b/migration/xbzrle.c @@ -174,3 +174,127 @@ int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t *dst, int dlen) return d; } + +#if defined(CONFIG_AVX512BW_OPT) +#pragma GCC push_options +#pragma GCC target("avx512bw") +#include <immintrin.h> +int xbzrle_encode_buffer_avx512(uint8_t *old_buf, uint8_t *new_buf, int slen, + uint8_t *dst, int dlen) +{ + uint32_t zrun_len = 0, nzrun_len = 0; + int d = 0, i = 0, num = 0; + uint8_t *nzrun_start = NULL; + /* add 1 to include residual part in main loop */ + uint32_t count512s = (slen >> 6) + 1; + /* countResidual is tail of data, i.e., countResidual = slen % 64 */ + uint32_t count_residual = slen & 0b111111; + bool never_same = true; + uint64_t mask_residual = 1; + mask_residual <<= count_residual; + mask_residual -= 1; + __m512i r = _mm512_set1_epi32(0); + + while (count512s) { + if (d + 2 > dlen) { + return -1; + } + + int bytes_to_check = 64; + uint64_t mask = 0xffffffffffffffff; + if (count512s == 1) { + bytes_to_check = count_residual; + mask = mask_residual; + } + __m512i old_data = _mm512_mask_loadu_epi8(r, + mask, old_buf + i); + __m512i new_data = _mm512_mask_loadu_epi8(r, + mask, new_buf + i); + uint64_t comp = _mm512_cmpeq_epi8_mask(old_data, new_data); + count512s--; + + bool is_same = (comp & 0x1); + while (bytes_to_check) { + if (is_same) { + if (nzrun_len) { + d += uleb128_encode_small(dst + d, nzrun_len); + if (d + nzrun_len > dlen) { + return -1; + } + nzrun_start = new_buf + i - nzrun_len; + memcpy(dst + d, nzrun_start, nzrun_len); + d += nzrun_len; + nzrun_len = 0; + } + /* 64 data at a time for speed */ + if (count512s && (comp == 0xffffffffffffffff)) { + i += 64; + zrun_len += 64; + break; + } + never_same = false; + num = __builtin_ctzll(~comp); + num = (num < bytes_to_check) ? num : bytes_to_check; + zrun_len += num; + bytes_to_check -= num; + comp >>= num; + i += num; + if (bytes_to_check) { + /* still has different data after same data */ + d += uleb128_encode_small(dst + d, zrun_len); + zrun_len = 0; + } else { + break; + } + } + if (never_same || zrun_len) { + /* + * never_same only acts if + * data begins with diff in first count512s + */ + d += uleb128_encode_small(dst + d, zrun_len); + zrun_len = 0; + never_same = false; + } + /* has diff, 64 data at a time for speed */ + if ((bytes_to_check == 64) && (comp == 0x0)) { + i += 64; + nzrun_len += 64; + break; + } + num = __builtin_ctzll(comp); + num = (num < bytes_to_check) ? num : bytes_to_check; + nzrun_len += num; + bytes_to_check -= num; + comp >>= num; + i += num; + if (bytes_to_check) { + /* mask like 111000 */ + d += uleb128_encode_small(dst + d, nzrun_len); + /* overflow */ + if (d + nzrun_len > dlen) { + return -1; + } + nzrun_start = new_buf + i - nzrun_len; + memcpy(dst + d, nzrun_start, nzrun_len); + d += nzrun_len; + nzrun_len = 0; + is_same = true; + } + } + } + + if (nzrun_len != 0) { + d += uleb128_encode_small(dst + d, nzrun_len); + /* overflow */ + if (d + nzrun_len > dlen) { + return -1; + } + nzrun_start = new_buf + i - nzrun_len; + memcpy(dst + d, nzrun_start, nzrun_len); + d += nzrun_len; + } + return d; +} +#pragma GCC pop_options +#endif |