From de542b3046a9b2adf6b331ddcc09539940036446 Mon Sep 17 00:00:00 2001 From: pubby Date: Mon, 17 Apr 2023 10:38:45 -0500 Subject: [PATCH] Faster q3_0 implementation, using two planes (#1) --- ggml.c | 214 +++++++++++++++++++++++++++------------------------------ 1 file changed, 102 insertions(+), 112 deletions(-) diff --git a/ggml.c b/ggml.c index 6a15d8b900613f..374078149760b5 100644 --- a/ggml.c +++ b/ggml.c @@ -606,12 +606,12 @@ typedef struct { static_assert(sizeof(block_q2_0) == sizeof(ggml_fp16_t) + QK2_0 / 4, "wrong q2_0 size/padding"); #define QK3_0 16 -typedef union { - struct { - uint16_t pad[3]; - ggml_fp16_t d; - }; - uint64_t qs; +typedef struct { + ggml_fp16_t d; + // Instead of representing q3_0 as a packed format "...210210210210", + // represent it as two planes: "...10101010" and "...2222" + uint16_t qhi; // The highest bit of each 3-bit number, packed together + uint32_t qlo; // The low 2-bits of each 3-bit number, packed together } block_q3_0; static_assert(sizeof(block_q3_0) == sizeof(ggml_fp16_t) + QK3_0 * 3 / 8, "wrong q3_0 size/padding"); @@ -691,17 +691,20 @@ static void quantize_row_q3_0(const float * restrict x, block_q3_0 * restrict y, const float d = max / -4; const float id = d ? 1.0f/d : 0.0f; - uint64_t qs = 0; + uint32_t lo = 0; + uint16_t hi = 0; for (int l = 0; l < QK3_0; l++) { const float v = x[i*QK3_0 + l]*id; const uint8_t vi = MIN(7, (int8_t)roundf(v) + 4); assert(vi < 8); - qs |= (uint64_t)vi << (l*3); + lo |= (vi & 3) << (l * 2); + hi |= ((vi >> 2) & 1) << l; } - y[i].qs = qs; - y[i].d = GGML_FP32_TO_FP16(d); // overwrite unused part of uint64_t qs + y[i].d = GGML_FP32_TO_FP16(d); + y[i].qlo = lo; + y[i].qhi = hi; } } @@ -1335,13 +1338,15 @@ static void dequantize_row_q3_0(const void * restrict vx, float * restrict y, in for (int i = 0; i < nb; i++) { const float d = GGML_FP16_TO_FP32(x[i].d); - uint64_t qs = x[i].qs; + uint_fast32_t lo = x[i].qlo; + uint_fast32_t hi = x[i].qhi << 2; for (int l = 0; l < QK3_0; l++) { - const int8_t vi = qs & 7; + const int8_t vi = (lo & 3) | (hi & 4); const float v = (vi - 4)*d; y[i*QK3_0 + l] = v; assert(!isnan(y[i*QK3_0 + l])); - qs >>= 3; + lo >>= 2; + hi >>= 1; } } } @@ -2193,6 +2198,39 @@ inline static void ggml_vec_dot_f16(const int n, float * restrict s, ggml_fp16_t *s = sumf; } +#if __AVX2__ || __AVX512F__ +// Computes the dot product of signed 8-bit integers packed into 256-bit vectors, +// converting the result to 32-bit floats packed into a 256-bit vector. +static inline __m256 dotMul(__m256i bx, __m256i by) { +# if __AVXVNNIINT8__ + // Perform multiplication and sum to 32-bit values + const __m256i i32 = _mm256_dpbssd_epi32(bx, by, _mm256_setzero_si256()); +# else + // Get absolute values of x vectors + const __m256i ax = _mm256_sign_epi8(bx, bx); + // Sign the values of the y vectors + const __m256i sy = _mm256_sign_epi8(by, bx); + // Perform multiplication and create 16-bit values + const __m256i dot = _mm256_maddubs_epi16(ax, sy); + + // Convert int16_t to int32_t by adding pairwise + const __m256i ones = _mm256_set1_epi16(1); + const __m256i i32 = _mm256_madd_epi16(ones, dot); +# endif + // Convert int32_t to float + return _mm256_cvtepi32_ps(i32); +} + +// Return horizontal sum of 32-bit floats packed into a 256-bit vector. +static inline float horizontalSum(__m256 acc) { + __m128 res = _mm256_extractf128_ps(acc, 1); + res = _mm_add_ps(res, _mm256_castps256_ps128(acc)); + res = _mm_add_ps(res, _mm_movehl_ps(res, res)); + res = _mm_add_ss(res, _mm_movehdup_ps(res)); + return _mm_cvtss_f32(res); +} +#endif + static void ggml_vec_dot_q2_0_q8_0(const int n, float * restrict s, const void * restrict vx, const void * restrict vy) { assert(n % QK2_0 == 0); const int nb = n / QK2_0; @@ -2222,30 +2260,15 @@ static void ggml_vec_dot_q2_0_q8_0(const int n, float * restrict s, const void * // Load y vector const __m256i by = _mm256_loadu_si256((const __m256i *)y[i].qs); - // Get absolute values of x vectors - const __m256i ax = _mm256_sign_epi8(bx, bx); - // Sign the values of the y vectors - const __m256i sy = _mm256_sign_epi8(by, bx); - // Perform multiplication and create 16-bit values - const __m256i dot = _mm256_maddubs_epi16(ax, sy); - - // Convert int16_t to int32_t by adding pairwise - const __m256i ones = _mm256_set1_epi16(1); - __m256i i32 = _mm256_madd_epi16(ones, dot); - - // Convert int32_t to float - __m256 p = _mm256_cvtepi32_ps(i32); + // Do the product: + __m256 p = dotMul(bx, by); // Apply the scale, and accumulate acc = _mm256_fmadd_ps(scale, p, acc); } // Return horizontal sum of the acc vector - __m128 res = _mm256_extractf128_ps(acc, 1); - res = _mm_add_ps(res, _mm256_castps256_ps128(acc)); - res = _mm_add_ps(res, _mm_movehl_ps(res, res)); - res = _mm_add_ss(res, _mm_movehdup_ps(res)); - sumf = _mm_cvtss_f32(res); + sumf = horizontalSum(acc); #else for (int i = 0; i < nb; i++) { const float d0 = GGML_FP16_TO_FP32(x[i].d); @@ -2270,6 +2293,20 @@ static void ggml_vec_dot_q2_0_q8_0(const int n, float * restrict s, const void * *s = sumf; } +// Lookup table used to convert q3_0 to SIMD vectors. +// Expands the bits of an 8-bit value into a 64 bit result, turning each bit into a byte. +// A zero bit turns into 0xFC, while a one bit turns into 0x00. +#define B0(n) 0x ## n +#define B1(n) B0(n ## FC), B0(n ## 00) +#define B2(n) B1(n ## FC), B1(n ## 00) +#define B3(n) B2(n ## FC), B2(n ## 00) +#define B4(n) B3(n ## FC), B3(n ## 00) +#define B5(n) B4(n ## FC), B4(n ## 00) +#define B6(n) B5(n ## FC), B5(n ## 00) +#define B7(n) B6(n ## FC), B6(n ## 00) +#define B8( ) B7( FC), B7( 00) +static const uint64_t ggml_q3_table[256] = { B8() }; + static void ggml_vec_dot_q3_0_q8_0(const int n, float * restrict s, const void * restrict vx, const void * restrict vy) { assert(n % QK3_0 == 0); const int nb = n / QK3_0; @@ -2282,103 +2319,54 @@ static void ggml_vec_dot_q3_0_q8_0(const int n, float * restrict s, const void * #if defined(__AVX2__) // Initialize accumulator with zeros - __m128 acc = _mm_setzero_ps(); + __m256 acc = _mm256_setzero_ps(); + for (int i = 0; i < nb/2; i++) { - const __m128 scale_y = _mm_set1_ps(y[i].d); - for (int u = 0; u < 2; u++) { // let the compiler unroll this - // Compute combined scale for the block - const __m128 scale_x = _mm_set1_ps(GGML_FP16_TO_FP32(x[i*2+u].d)); - const __m128 scale = _mm_mul_ps(scale_x, scale_y); - - __m256i bxx = _mm256_set1_epi64x(x[i*2+u].qs); - - // legend: _=zero +=one .=don't care 0-f=3bit quantized values s=fp16 scale - - // shift the copies to be able to reach all values - // 255 192 128 64 0 - // | | | | - // sssssfedcba9876543210sssssfedcba9876543210sssssfedcba9876543210sssssfedcba9876543210 in - // sssfedcba9876543210_______________________sfedcba9876543210____sssssfedcba9876543210 shift left - // _______________________sssssfedcba98765432__________________________________________ shift right - // sssfedcba9876543210____sssssfedcba98765432sfedcba9876543210____sssssfedcba9876543210 out - // ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ - // e b 6 3 _ . f a 7 2 c 9 4 1 _ . d 8 5 0 - const __m256i shift_l = _mm256_set_epi64x(2*3, 64, 4*3, 0); - const __m256i shift_r = _mm256_set_epi64x( 64, 2*3, 64, 64); - bxx = _mm256_or_si256(_mm256_sllv_epi64(bxx, shift_l), _mm256_srlv_epi64(bxx, shift_r)); - - // add to itself in masked places to shift some values left one bit - // 127 64 0 - // | | | | | | | | | | | | | | | | - // ssssfffeeedddcccbbbaaa999888777666555444333222111000____________ssssssssssssssssfffeeedddcccbbbaaa999888777666555444333222111000 in - // _____________________++++____________________++++____________________________________++++____________________++++_______________ mask - // _____________________.999____________________.111____________________________________.ddd____________________.555_______________ masked - // .............ccc.....999.............444.....111....____________.....................ddd.............888.....555.............000 sum - // - // 255 192 128 - // | | | | | | | | | | | | | | | | - // ssssssssssfffeeedddcccbbbaaa999888777666555444333222111000____________ssssssssssssssssfffeeedddcccbbbaaa999888777666555444333222 in - // _____________________++++____________________++++____________________________________++++____________________++++_______________ mask - // _____________________.bbb____________________.333____________________________________.fff____________________.777_______________ masked - // .............eee.....bbb.............666.....333..........____________...............fff.............aaa.....777.............222 sum - const __m256i doublemask = _mm256_set1_epi64x(0x078000078000); - bxx = _mm256_add_epi64(bxx, _mm256_and_si256(doublemask, bxx)); - - // collect 16 bytes from 256 into 128 bits - const __m256i shufmask = _mm256_set_epi8( - 5,14,-1,-1,13, 3,-1,-1, 2,11,-1,-1,10, 0,-1,-1, - -1,-1, 5,14,-1,-1,13, 3,-1,-1, 2,11,-1,-1,10, 0); - bxx = _mm256_shuffle_epi8(bxx, shufmask); - - __m128i bx = _mm_or_si128(_mm256_castsi256_si128(bxx), _mm256_extracti128_si256(bxx, 1)); - - const __m128i mask = _mm_set1_epi8(7); - bx = _mm_and_si128(mask, bx); - - const __m128i off = _mm_set1_epi8(4); - bx = _mm_sub_epi8(bx, off); - - const __m128i by = _mm_loadu_si128((const __m128i *)(y[i].qs + u*QK3_0)); + __m256i bx = bytesFromCrumbs(x[i*2+1].qlo, x[i*2].qlo); - // Get absolute values of x vectors - const __m128i ax = _mm_sign_epi8(bx, bx); - // Sign the values of the y vectors - const __m128i sy = _mm_sign_epi8(by, bx); - // Perform multiplication and create 16-bit values - const __m128i dot = _mm_maddubs_epi16(ax, sy); + __m256i const bxhi = _mm256_set_epi64x( + ggml_q3_table[x[i*2+1].qhi >> 8], ggml_q3_table[x[i*2+1].qhi & 0xFF], + ggml_q3_table[x[i*2+0].qhi >> 8], ggml_q3_table[x[i*2+0].qhi & 0xFF]); - // Convert int16_t to int32_t by adding pairwise - const __m128i ones = _mm_set1_epi16(1); - __m128i i32 = _mm_madd_epi16(dot, ones); + // OR the high bits (which also handles the sign): + bx = _mm256_or_si256(bx, bxhi); - // Convert int32_t to float - const __m128 p = _mm_cvtepi32_ps(i32); + // Compute combined scale for the block + const __m128 scale_lo = _mm_set1_ps(GGML_FP16_TO_FP32(x[i*2+0].d)); + const __m128 scale_hi = _mm_set1_ps(GGML_FP16_TO_FP32(x[i*2+1].d)); + __m256 scale = _mm256_set_m128(scale_hi, scale_lo); + scale = _mm256_mul_ps(scale, _mm256_broadcast_ss(&y[i].d)); - // Apply the scale, and accumulate - acc = _mm_fmadd_ps(scale, p, acc); - } + // Load y vector + const __m256i by = _mm256_loadu_si256((const __m256i *)y[i].qs); + + // Do the product, + __m256 p = dotMul(bx, by); + + // Apply the scale, and accumulate + acc = _mm256_fmadd_ps(scale, p, acc); } // Return horizontal sum of the acc vector - __m128 res = _mm_add_ps(acc, _mm_movehl_ps(acc, acc)); - res = _mm_add_ss(res, _mm_movehdup_ps(res)); - sumf = _mm_cvtss_f32(res); + sumf = horizontalSum(acc); #else for (int i = 0; i < nb; i++) { const float d0 = GGML_FP16_TO_FP32(x[i].d); const float d1 = y[i/2].d; - uint64_t qs0 = x[i].qs; + uint_fast32_t lo0 = x[i].qlo; + uint_fast32_t hi0 = x[i].qhi << 2; const int8_t * restrict p1 = y[i/2].qs + (i%2)*QK3_0; int sumi = 0; - for (int j = 0; j < QK3_0; j++) { - const int8_t i0 = (int8_t)(qs0 & 7) - 4; - const int_fast16_t i1 = p1[j]; + for (int l = 0; l < QK3_0; l++) { + const int8_t i0 = (int8_t)((lo0 & 3) | ((hi0 & 4) - 4)); + const int_fast16_t i1 = p1[l]; sumi += i0 * i1; - qs0 >>= 3; + lo0 >>= 2; + hi0 >>= 1; } sumf += d0 * d1 * sumi; } @@ -11630,11 +11618,13 @@ size_t ggml_quantize_q3_0(const float * src, void * dst, int n, int k, int64_t h quantize_row_q3_0(src + j, y, k); for (int i = 0; i < nb; i++) { - uint64_t qs = y[i].qs; + uint_fast32_t lo = y[i].qlo; + uint_fast32_t hi = y[i].qhi << 2; for (int l = 0; l < QK3_0; l++) { - const int8_t vi = qs & 7; + int8_t vi = (lo & 3) | (hi & 4); hist[vi]++; - qs >>= 3; + lo >>= 2; + hi >>= 1; } } }