q4_0c: disable prefetching on M1

Author: unbounded

ggml.c

@@ -1154,13 +1154,17 @@ static void quantize_row_q4_0c_reference(const float * restrict x, uint8_t * res
         float id[2];
         for (int j = 0; j < 2; j++) {
             float amax = 0.0f; // absolute max
+            float max = 0.0f;
 
             for (int l = 0; l < QK4_0; l++) {
                 const float v = xb[j][l];
-                amax = MAX(amax, fabsf(v));
+                if (amax < fabsf(v)) {
+                    amax = fabsf(v);
+                    max = v;
+                }
             }
 
-            d[j] = amax / ((1 << 3) - 1);
+            d[j] = max / -8;
             id[j] = d[j] ? 1.0f/d[j] : 0.0f;
         }
 
@@ -1169,10 +1173,10 @@ static void quantize_row_q4_0c_reference(const float * restrict x, uint8_t * res
 
         for (int l = 0; l < QK4_0; l++) {
             const float v0 = xb[0][l]*id[0];
-            const uint8_t vi0 = (int8_t)roundf(v0) + 8;
+            const uint8_t vi0 = MIN(15, (int8_t)roundf(v0) + 8);
 
             const float v1 = xb[1][l]*id[1];
-            const uint8_t vi1 = (int8_t)roundf(v1) + 8;
+            const uint8_t vi1 = MIN(15, (int8_t)roundf(v1) + 8);
 
             assert(vi0 < 16);
             assert(vi1 < 16);
@@ -3126,16 +3130,19 @@ static void ggml_vec_dot_q4_0c_q8_0c(const int n, float * restrict s, const void
     float sumf = 0.0;
 
 #if defined(__ARM_NEON)
-    const int ahead=80;
     float32x4_t sumv0 = vdupq_n_f32(0.0f);
     float32x4_t sumv1 = vdupq_n_f32(0.0f);
 
     for (int i = 0; i < nb/2; i++) {
+        // Disable prefetching on M1 for now.
+#ifndef __APPLE__
+        const int ahead=80;
         __builtin_prefetch(&xqs[i*QK4_0 + 64*ahead]);
         __builtin_prefetch(&yqs[2*i*QK8_0C + 64*ahead]);
         __builtin_prefetch(&yqs[2*i*QK8_0C + 64*ahead + 64]);
         __builtin_prefetch(&xds[2*i + 64/4*ahead]);
         __builtin_prefetch(&yds[2*i + 64/4*ahead]);
+#endif
 
         const int dst0 = i + i/2*2;      // 0, 1, 4, 5, 8, 9, ...
         const int dst1 = i + i/2*2 + 2;  // 2, 3, 6, 7, 10, 11 ...
@@ -9738,11 +9745,13 @@ static void ggml_compute_forward_alibi(
                 ggml_compute_forward_alibi_f32(params, src0, src1, dst);
             } break;
         case GGML_TYPE_Q4_0:
+        case GGML_TYPE_Q4_0C:
         case GGML_TYPE_Q4_1:
         case GGML_TYPE_Q4_2:
         case GGML_TYPE_Q5_0:
         case GGML_TYPE_Q5_1:
         case GGML_TYPE_Q8_0:
+        case GGML_TYPE_Q8_0C:
         case GGML_TYPE_Q8_1:
         case GGML_TYPE_I8:
         case GGML_TYPE_I16: