AVX BF16 and single scale quant optimizations (#10212)

* use 128 bit loads (i've tried 256->128 to death and its slower)

* double accumulator

* avx bf16 vec dot

* +3% q4_0 inference

* +7% tg +5% pp compared to master

* slower f16c version, kep for reference

* 256b version, also slow. i tried :)

* revert f16

* faster with madd

* split to functions

* Q8_0 and IQ4_NL, 5-7% faster

* fix potential overflow (performance reduced)

* 16 bit add for q4_0 only

* merge

Author: netrunnereve

ggml/src/ggml-cpu/ggml-cpu-quants.c

@@ -150,6 +150,28 @@ static inline __m128i packNibbles( __m256i bytes )
 #endif
 }
 #elif defined(__AVX__)
+static inline __m128i packNibbles( __m128i bytes1, __m128i bytes2 )
+{
+    // Move bits within 16-bit lanes from 0000_abcd_0000_efgh into 0000_0000_abcd_efgh
+    const __m128i lowByte = _mm_set1_epi16( 0xFF );
+    __m128i high = _mm_andnot_si128( lowByte, bytes1 );
+    __m128i low = _mm_and_si128( lowByte, bytes1 );
+    high = _mm_srli_epi16( high, 4 );
+    bytes1 = _mm_or_si128( low, high );
+    high = _mm_andnot_si128( lowByte, bytes2 );
+    low = _mm_and_si128( lowByte, bytes2 );
+    high = _mm_srli_epi16( high, 4 );
+    bytes2 = _mm_or_si128( low, high );
+
+    return _mm_packus_epi16( bytes1, bytes2);
+}
+
+static inline __m128i mul_add_epi8_sse(const __m128i x, const __m128i y) {
+    const __m128i ax = _mm_sign_epi8(x, x);
+    const __m128i sy = _mm_sign_epi8(y, x);
+    return _mm_maddubs_epi16(ax, sy);
+}
+
 // spread 32 bits to 32 bytes { 0x00, 0xFF }
 static inline __m256i bytes_from_bits_32(const uint8_t * x) {
     uint32_t x32;
@@ -217,26 +239,29 @@ static inline __m256 mul_sum_i8_pairs_float(const __m256i x, const __m256i y) {
     return sum_i16_pairs_float(doth, dotl);
 }
 
-static inline __m128i packNibbles( __m128i bytes1, __m128i bytes2 )
-{
-    // Move bits within 16-bit lanes from 0000_abcd_0000_efgh into 0000_0000_abcd_efgh
-    const __m128i lowByte = _mm_set1_epi16( 0xFF );
-    __m128i high = _mm_andnot_si128( lowByte, bytes1 );
-    __m128i low = _mm_and_si128( lowByte, bytes1 );
-    high = _mm_srli_epi16( high, 4 );
-    bytes1 = _mm_or_si128( low, high );
-    high = _mm_andnot_si128( lowByte, bytes2 );
-    low = _mm_and_si128( lowByte, bytes2 );
-    high = _mm_srli_epi16( high, 4 );
-    bytes2 = _mm_or_si128( low, high );
+// larger version of mul_sum_i8_pairs_float where x and y are each represented by four 128-bit vectors
+static inline __m256 mul_sum_i8_quad_float(const __m128i x_1_0, const __m128i x_1_1, const __m128i x_2_0, const __m128i x_2_1,
+                                           const __m128i y_1_0, const __m128i y_1_1, const __m128i y_2_0, const __m128i y_2_1) {
+    const __m128i mone = _mm_set1_epi16(1);
 
-    return _mm_packus_epi16( bytes1, bytes2);
+    const __m128i p16_1_0 = mul_add_epi8_sse(x_1_0, y_1_0);
+    const __m128i p16_1_1 = mul_add_epi8_sse(x_1_1, y_1_1);
+    const __m128i p16_2_0 = mul_add_epi8_sse(x_2_0, y_2_0);
+    const __m128i p16_2_1 = mul_add_epi8_sse(x_2_1, y_2_1);
+    const __m128i p_1_0 = _mm_madd_epi16(p16_1_0, mone);
+    const __m128i p_1_1 = _mm_madd_epi16(p16_1_1, mone);
+    const __m128i p_2_0 = _mm_madd_epi16(p16_2_0, mone);
+    const __m128i p_2_1 = _mm_madd_epi16(p16_2_1, mone);
+    const __m128i p_1 = _mm_add_epi32(p_1_0, p_1_1);
+    const __m128i p_2 = _mm_add_epi32(p_2_0, p_2_1);
+    return _mm256_cvtepi32_ps(MM256_SET_M128I(p_2, p_1));
 }
 
-static inline __m128i mul_add_epi8_sse(const __m128i x, const __m128i y) {
-    const __m128i ax = _mm_sign_epi8(x, x);
-    const __m128i sy = _mm_sign_epi8(y, x);
-    return _mm_maddubs_epi16(ax, sy);
+// quad fp16 delta calculation
+static inline __m256 quad_fp16_delta_float(const float x0, const float y0, const float x1, const float y1) {
+    // GGML_FP16_TO_FP32 is faster than Intel F16C
+    return _mm256_set_m128(_mm_set1_ps(GGML_FP16_TO_FP32(x1) * GGML_FP16_TO_FP32(y1)),
+                           _mm_set1_ps(GGML_FP16_TO_FP32(x0) * GGML_FP16_TO_FP32(y0)));
 }
 #endif
 #elif defined(__SSSE3__)
@@ -2004,10 +2029,7 @@ void ggml_vec_dot_q4_0_q8_0(int n, float * restrict s, size_t bs, const void * r
 
     sumf = hsum_float_8(acc);
 #elif defined(__AVX__)
-    const __m128i mone = _mm_set1_epi16(1);
-
-    __m256 accum1 = _mm256_setzero_ps();
-    __m256 accum2 = _mm256_setzero_ps();
+    __m256 accum = _mm256_setzero_ps();
     for (; ib + 1 < nb; ib += 2) {
         const __m128i q4bits_1 = _mm_loadu_si128((const __m128i *)x[ib + 0].qs);
         const __m128i q4bits_2 = _mm_loadu_si128((const __m128i *)x[ib + 1].qs);
@@ -2020,21 +2042,20 @@ void ggml_vec_dot_q4_0_q8_0(int n, float * restrict s, size_t bs, const void * r
         const __m128i q4b_1_1 = _mm_sub_epi8(_mm_and_si128(_mm_set1_epi8(15), _mm_srli_epi16(q4bits_1, 4)), _mm_set1_epi8(8));
         const __m128i q4b_2_0 = _mm_sub_epi8(_mm_and_si128(_mm_set1_epi8(15), q4bits_2), _mm_set1_epi8(8));
         const __m128i q4b_2_1 = _mm_sub_epi8(_mm_and_si128(_mm_set1_epi8(15), _mm_srli_epi16(q4bits_2, 4)), _mm_set1_epi8(8));
+
         const __m128i p16_1_0 = mul_add_epi8_sse(q4b_1_0, q8b_1_0);
         const __m128i p16_1_1 = mul_add_epi8_sse(q4b_1_1, q8b_1_1);
         const __m128i p16_2_0 = mul_add_epi8_sse(q4b_2_0, q8b_2_0);
         const __m128i p16_2_1 = mul_add_epi8_sse(q4b_2_1, q8b_2_1);
-        const __m128i p_1_0 = _mm_madd_epi16(p16_1_0, mone);
-        const __m128i p_1_1 = _mm_madd_epi16(p16_1_1, mone);
-        const __m128i p_2_0 = _mm_madd_epi16(p16_2_0, mone);
-        const __m128i p_2_1 = _mm_madd_epi16(p16_2_1, mone);
-        accum1 = _mm256_add_ps(_mm256_mul_ps(_mm256_set1_ps(GGML_FP16_TO_FP32(y[ib + 0].d)*GGML_FP16_TO_FP32(x[ib + 0].d)),
-                _mm256_cvtepi32_ps(MM256_SET_M128I(p_1_1, p_1_0))), accum1);
-        accum2 = _mm256_add_ps(_mm256_mul_ps(_mm256_set1_ps(GGML_FP16_TO_FP32(y[ib + 1].d)*GGML_FP16_TO_FP32(x[ib + 1].d)),
-                _mm256_cvtepi32_ps(MM256_SET_M128I(p_2_1, p_2_0))), accum2);
+        const __m128i p_1 = _mm_add_epi16(p16_1_0, p16_1_1);
+        const __m128i p_2 = _mm_add_epi16(p16_2_0, p16_2_1);
+        const __m256 p =  sum_i16_pairs_float(p_2, p_1);
+
+        const __m256 deltas = quad_fp16_delta_float(x[ib].d, y[ib].d, x[ib + 1].d, y[ib + 1].d);
+        accum = _mm256_add_ps(_mm256_mul_ps(deltas, p), accum);
     }
 
-    sumf = hsum_float_8(_mm256_add_ps(accum1, accum2));
+    sumf = hsum_float_8(accum);
 #elif defined(__SSSE3__)
     // set constants
     const __m128i lowMask = _mm_set1_epi8(0xF);
@@ -3535,7 +3556,7 @@ void ggml_vec_dot_q8_0_q8_0(int n, float * restrict s, size_t bs, const void * r
     }
 
     sumf = vaddvq_f32(sumv0) + vaddvq_f32(sumv1);
-#elif defined(__AVX2__) || defined(__AVX__)
+#elif defined(__AVX2__)
     // Initialize accumulator with zeros
     __m256 acc = _mm256_setzero_ps();
 
@@ -3549,14 +3570,29 @@ void ggml_vec_dot_q8_0_q8_0(int n, float * restrict s, size_t bs, const void * r
         const __m256 q = mul_sum_i8_pairs_float(qx, qy);
 
         // Multiply q with scale and accumulate
-#if defined(__AVX2__)
         acc = _mm256_fmadd_ps( d, q, acc );
-#else
-        acc = _mm256_add_ps( _mm256_mul_ps( d, q ), acc );
-#endif
     }
 
     sumf = hsum_float_8(acc);
+#elif defined(__AVX__)
+    __m256 accum = _mm256_setzero_ps();
+
+    for (; ib + 1 < nb; ib += 2) {
+        const __m128i qx_1_0 = _mm_loadu_si128((const __m128i *)x[ib].qs);
+        const __m128i qx_1_1 = _mm_loadu_si128((const __m128i *)x[ib].qs + 1);
+        const __m128i qx_2_0 = _mm_loadu_si128((const __m128i *)x[ib + 1].qs);
+        const __m128i qx_2_1 = _mm_loadu_si128((const __m128i *)x[ib + 1].qs + 1);
+        const __m128i qy_1_0 = _mm_loadu_si128((const __m128i *)y[ib].qs);
+        const __m128i qy_1_1 = _mm_loadu_si128((const __m128i *)y[ib].qs + 1);
+        const __m128i qy_2_0 = _mm_loadu_si128((const __m128i *)y[ib + 1].qs);
+        const __m128i qy_2_1 = _mm_loadu_si128((const __m128i *)y[ib + 1].qs + 1);
+
+        const __m256 p = mul_sum_i8_quad_float(qx_1_0, qx_1_1, qx_2_0, qx_2_1, qy_1_0, qy_1_1, qy_2_0, qy_2_1);
+        const __m256 deltas = quad_fp16_delta_float(x[ib].d, y[ib].d, x[ib + 1].d, y[ib + 1].d);
+        accum = _mm256_add_ps(_mm256_mul_ps(deltas, p), accum);
+    }
+
+    sumf = hsum_float_8(accum);
 #elif defined(__riscv_v_intrinsic)
     size_t vl = __riscv_vsetvl_e8m1(qk);
 
@@ -10322,10 +10358,8 @@ void ggml_vec_dot_iq4_nl_q8_0(int n, float * restrict s, size_t bs, const void *
 #elif defined __AVX__
     const __m128i values128 = _mm_loadu_si128((const __m128i*)kvalues_iq4nl);
     const __m128i m4b  = _mm_set1_epi8(0x0f);
-    const __m128i mone = _mm_set1_epi16(1);
 
-    __m256 accum1 = _mm256_setzero_ps();
-    __m256 accum2 = _mm256_setzero_ps();
+    __m256 accum = _mm256_setzero_ps();
     for (; ib + 1 < nb; ib += 2) {
         const __m128i q4bits_1 = _mm_loadu_si128((const __m128i *)x[ib + 0].qs);
         const __m128i q4bits_2 = _mm_loadu_si128((const __m128i *)x[ib + 1].qs);
@@ -10338,21 +10372,13 @@ void ggml_vec_dot_iq4_nl_q8_0(int n, float * restrict s, size_t bs, const void *
         const __m128i q4b_1_1 = _mm_shuffle_epi8(values128, _mm_and_si128(_mm_srli_epi16(q4bits_1, 4), m4b));
         const __m128i q4b_2_0 = _mm_shuffle_epi8(values128, _mm_and_si128(q4bits_2, m4b));
         const __m128i q4b_2_1 = _mm_shuffle_epi8(values128, _mm_and_si128(_mm_srli_epi16(q4bits_2, 4), m4b));
-        const __m128i p16_1_0 = mul_add_epi8_sse(q4b_1_0, q8b_1_0);
-        const __m128i p16_1_1 = mul_add_epi8_sse(q4b_1_1, q8b_1_1);
-        const __m128i p16_2_0 = mul_add_epi8_sse(q4b_2_0, q8b_2_0);
-        const __m128i p16_2_1 = mul_add_epi8_sse(q4b_2_1, q8b_2_1);
-        const __m128i p_1_0 = _mm_madd_epi16(p16_1_0, mone);
-        const __m128i p_1_1 = _mm_madd_epi16(p16_1_1, mone);
-        const __m128i p_2_0 = _mm_madd_epi16(p16_2_0, mone);
-        const __m128i p_2_1 = _mm_madd_epi16(p16_2_1, mone);
-        accum1 = _mm256_add_ps(_mm256_mul_ps(_mm256_set1_ps(GGML_FP16_TO_FP32(y[ib + 0].d)*GGML_FP16_TO_FP32(x[ib + 0].d)),
-                _mm256_cvtepi32_ps(MM256_SET_M128I(p_1_1, p_1_0))), accum1);
-        accum2 = _mm256_add_ps(_mm256_mul_ps(_mm256_set1_ps(GGML_FP16_TO_FP32(y[ib + 1].d)*GGML_FP16_TO_FP32(x[ib + 1].d)),
-                _mm256_cvtepi32_ps(MM256_SET_M128I(p_2_1, p_2_0))), accum2);
+
+        const __m256 p = mul_sum_i8_quad_float(q4b_1_0, q4b_1_1, q4b_2_0, q4b_2_1, q8b_1_0, q8b_1_1, q8b_2_0, q8b_2_1);
+        const __m256 deltas = quad_fp16_delta_float(x[ib].d, y[ib].d, x[ib + 1].d, y[ib + 1].d);
+        accum = _mm256_add_ps(_mm256_mul_ps(deltas, p), accum);
     }
 
-    sumf = hsum_float_8(_mm256_add_ps(accum1, accum2));
+    sumf = hsum_float_8(accum);
 
 #elif defined(__POWER9_VECTOR__)
     const vector signed char lowMask = vec_splats((signed char)0xF);

ggml/src/ggml-cpu/ggml-cpu.c

@@ -1469,8 +1469,12 @@ static void ggml_vec_dot_bf16(int n, float * restrict s, size_t bs, ggml_bf16_t
     sumf += (ggml_float)_mm512_reduce_add_ps(c2);
 
 #undef LOAD
-#elif defined(__AVX2__)
+#elif defined(__AVX2__) || defined(__AVX__)
+#if defined(__AVX2__)
 #define LOAD(p) _mm256_castsi256_ps(_mm256_slli_epi32(_mm256_cvtepu16_epi32(_mm_loadu_si128((const __m128i *)(p))), 16))
+#else
+#define LOAD(p) _mm256_castsi256_ps(_mm256_insertf128_si256(_mm256_castsi128_si256(_mm_slli_epi32(_mm_cvtepu16_epi32(_mm_loadu_si128((const __m128i *)(p))), 16)), (_mm_slli_epi32(_mm_cvtepu16_epi32(_mm_bsrli_si128(_mm_loadu_si128((const __m128i *)(p)), 8)), 16)), 1))
+#endif
     __m256 c1 = _mm256_setzero_ps();
     __m256 c2 = _mm256_setzero_ps();
     __m256 c3 = _mm256_setzero_ps();