ggml : use q4_0_q8_0 and q4_2_q8_0

Author: ggerganov

ggml.c

@@ -1825,9 +1825,9 @@ static void dequantize_row_q8_0(const void * restrict vx, float * restrict y, in
     }
 }
 
-static void ggml_vec_dot_q4_0_q8_1(const int n, float * restrict s, const void * restrict vx, const void * restrict vy);
+static void ggml_vec_dot_q4_0_q8_0(const int n, float * restrict s, const void * restrict vx, const void * restrict vy);
 static void ggml_vec_dot_q4_1_q8_1(const int n, float * restrict s, const void * restrict vx, const void * restrict vy);
-static void ggml_vec_dot_q4_2_q8_1(const int n, float * restrict s, const void * restrict vx, const void * restrict vy);
+static void ggml_vec_dot_q4_2_q8_0(const int n, float * restrict s, const void * restrict vx, const void * restrict vy);
 static void ggml_vec_dot_q4_3_q8_1(const int n, float * restrict s, const void * restrict vx, const void * restrict vy);
 static void ggml_vec_dot_q8_0_q8_0(const int n, float * restrict s, const void * restrict vx, const void * restrict vy);
 
@@ -1837,7 +1837,7 @@ static const quantize_fns_t quantize_fns[GGML_TYPE_COUNT] = {
         .quantize_row_q           = quantize_row_q4_0,
         .quantize_row_q_reference = (quantize_row_q_t) quantize_row_q4_0_reference,
         .quantize_row_q_dot       = quantize_row_q8_1,
-        .vec_dot_q                = ggml_vec_dot_q4_0_q8_1,
+        .vec_dot_q                = ggml_vec_dot_q4_0_q8_0,
     },
     [GGML_TYPE_Q4_1] = {
         .dequantize_row_q         = dequantize_row_q4_1,
@@ -1851,7 +1851,7 @@ static const quantize_fns_t quantize_fns[GGML_TYPE_COUNT] = {
         .quantize_row_q           = quantize_row_q4_2,
         .quantize_row_q_reference = (quantize_row_q_t) quantize_row_q4_2_reference,
         .quantize_row_q_dot       = quantize_row_q8_1,
-        .vec_dot_q                = ggml_vec_dot_q4_2_q8_1,
+        .vec_dot_q                = ggml_vec_dot_q4_2_q8_0,
     },
     [GGML_TYPE_Q4_3] = {
         .dequantize_row_q         = dequantize_row_q4_3,
@@ -2475,7 +2475,7 @@ inline static void ggml_vec_dot_f16(const int n, float * restrict s, ggml_fp16_t
     *s = sumf;
 }
 
-static void ggml_vec_dot_q4_0_q8_1(const int n, float * restrict s, const void * restrict vx, const void * restrict vy) {
+static void ggml_vec_dot_q4_0_q8_0(const int n, float * restrict s, const void * restrict vx, const void * restrict vy) {
     const int nb = n / QK8_1;
 
     assert(n % QK8_1 == 0);
@@ -2488,17 +2488,14 @@ static void ggml_vec_dot_q4_0_q8_1(const int n, float * restrict s, const void *
     float32x4_t sumv0 = vdupq_n_f32(0.0f);
     float32x4_t sumv1 = vdupq_n_f32(0.0f);
 
-    float sum8 = 0;
-
     for (int i = 0; i < nb; i += 2) {
         const block_q4_0 * restrict x0 = &x[i + 0];
         const block_q4_0 * restrict x1 = &x[i + 1];
         const block_q8_1 * restrict y0 = &y[i + 0];
         const block_q8_1 * restrict y1 = &y[i + 1];
 
-        sum8 += x0->d * (y0->s0 + y0->s1) + x1->d * (y1->s0 + y1->s1);
-
         const uint8x16_t m4b   = vdupq_n_u8(0xf);
+        const int8x16_t  s8b   = vdupq_n_s8(0x8);
 
         const uint8x16_t v0_0 = vld1q_u8(x0->qs);
         const uint8x16_t v0_1 = vld1q_u8(x1->qs);
@@ -2509,6 +2506,12 @@ static void ggml_vec_dot_q4_0_q8_1(const int n, float * restrict s, const void *
         const int8x16_t v0_1l = vreinterpretq_s8_u8(vandq_u8  (v0_1, m4b));
         const int8x16_t v0_1h = vreinterpretq_s8_u8(vshrq_n_u8(v0_1, 4));
 
+        // sub 8
+        const int8x16_t v0_0ls = vsubq_s8(v0_0l, s8b);
+        const int8x16_t v0_0hs = vsubq_s8(v0_0h, s8b);
+        const int8x16_t v0_1ls = vsubq_s8(v0_1l, s8b);
+        const int8x16_t v0_1hs = vsubq_s8(v0_1h, s8b);
+
         // load y
         const int8x16_t v1_0l = vld1q_s8(y0->qs);
         const int8x16_t v1_0h = vld1q_s8(y0->qs + 16);
@@ -2523,21 +2526,21 @@ static void ggml_vec_dot_q4_0_q8_1(const int n, float * restrict s, const void *
 
 #if defined(__ARM_FEATURE_DOTPROD)
         // dot product into int32x4_t
-        const int32x4_t p_0 = vdotq_s32(vdotq_s32(vdupq_n_s32(0), v0_0l, v1_0ls), v0_0h, v1_0hs);
-        const int32x4_t p_1 = vdotq_s32(vdotq_s32(vdupq_n_s32(0), v0_1l, v1_1ls), v0_1h, v1_1hs);
+        const int32x4_t p_0 = vdotq_s32(vdotq_s32(vdupq_n_s32(0), v0_0ls, v1_0ls), v0_0hs, v1_0hs);
+        const int32x4_t p_1 = vdotq_s32(vdotq_s32(vdupq_n_s32(0), v0_1ls, v1_1ls), v0_1hs, v1_1hs);
 
         sumv0 = vmlaq_n_f32(sumv0, vcvtq_f32_s32(p_0), x0->d*y0->d);
         sumv1 = vmlaq_n_f32(sumv1, vcvtq_f32_s32(p_1), x1->d*y1->d);
 #else
-        const int16x8_t pl0l = vmull_s8(vget_low_s8 (v0_0l), vget_low_s8 (v1_0ls));
-        const int16x8_t pl0h = vmull_s8(vget_high_s8(v0_0l), vget_high_s8(v1_0ls));
-        const int16x8_t ph0l = vmull_s8(vget_low_s8 (v0_0h), vget_low_s8 (v1_0hs));
-        const int16x8_t ph0h = vmull_s8(vget_high_s8(v0_0h), vget_high_s8(v1_0hs));
+        const int16x8_t pl0l = vmull_s8(vget_low_s8 (v0_0ls), vget_low_s8 (v1_0ls));
+        const int16x8_t pl0h = vmull_s8(vget_high_s8(v0_0ls), vget_high_s8(v1_0ls));
+        const int16x8_t ph0l = vmull_s8(vget_low_s8 (v0_0hs), vget_low_s8 (v1_0hs));
+        const int16x8_t ph0h = vmull_s8(vget_high_s8(v0_0hs), vget_high_s8(v1_0hs));
 
-        const int16x8_t pl1l = vmull_s8(vget_low_s8 (v0_1l), vget_low_s8 (v1_1ls));
-        const int16x8_t pl1h = vmull_s8(vget_high_s8(v0_1l), vget_high_s8(v1_1ls));
-        const int16x8_t ph1l = vmull_s8(vget_low_s8 (v0_1h), vget_low_s8 (v1_1hs));
-        const int16x8_t ph1h = vmull_s8(vget_high_s8(v0_1h), vget_high_s8(v1_1hs));
+        const int16x8_t pl1l = vmull_s8(vget_low_s8 (v0_1ls), vget_low_s8 (v1_1ls));
+        const int16x8_t pl1h = vmull_s8(vget_high_s8(v0_1ls), vget_high_s8(v1_1ls));
+        const int16x8_t ph1l = vmull_s8(vget_low_s8 (v0_1hs), vget_low_s8 (v1_1hs));
+        const int16x8_t ph1h = vmull_s8(vget_high_s8(v0_1hs), vget_high_s8(v1_1hs));
 
         const int32x4_t pl0 = vaddq_s32(vpaddlq_s16(pl0l), vpaddlq_s16(pl0h));
         const int32x4_t ph0 = vaddq_s32(vpaddlq_s16(ph0l), vpaddlq_s16(ph0h));
@@ -2549,7 +2552,7 @@ static void ggml_vec_dot_q4_0_q8_1(const int n, float * restrict s, const void *
 #endif
     }
 
-    *s = vaddvq_f32(sumv0) + vaddvq_f32(sumv1) - 8 * sum8;
+    *s = vaddvq_f32(sumv0) + vaddvq_f32(sumv1);
 #elif defined(__AVX2__)
     // Initialize accumulator with zeros
     __m256 acc = _mm256_setzero_ps();
@@ -2775,7 +2778,7 @@ static void ggml_vec_dot_q4_1_q8_1(const int n, float * restrict s, const void *
 #endif
 }
 
-static void ggml_vec_dot_q4_2_q8_1(const int n, float * restrict s, const void * restrict vx, const void * restrict vy) {
+static void ggml_vec_dot_q4_2_q8_0(const int n, float * restrict s, const void * restrict vx, const void * restrict vy) {
     const int nb = n / QK8_1;
 
     assert(n % QK8_1 == 0);