From 459e93cce07cab9052c06b5bf360819893442e1e Mon Sep 17 00:00:00 2001
From: slaren <2141330+slaren@users.noreply.github.com>
Date: Sat, 25 Mar 2023 19:31:48 +0100
Subject: [PATCH] Add AVX2 implementation of dequantize_row_q4_1 (#505)
---
ggml.c | 34 +++++++++++++++++++++++++++++++++-
1 file changed, 33 insertions(+), 1 deletion(-)
diff --git a/ggml.c b/ggml.c
index b566b56..c9a4e86 100644
--- a/ggml.c
+++ b/ggml.c
@@ -783,7 +783,7 @@ void dequantize_row_q4_0(const void * restrict x, float * restrict y, int k) {
// Scale and store
for (int j = 0; j < 4; j++) {
- __m256 result = _mm256_mul_ps(vf[j], d_v);
+ const __m256 result = _mm256_mul_ps(vf[j], d_v);
_mm256_storeu_ps(y + i * QK + l + j*8, result);
}
}
@@ -879,6 +879,37 @@ void dequantize_row_q4_1(const void * restrict x, float * restrict y, int k) {
const uint8_t * restrict pm = ((const uint8_t *)x + 0*bs + sizeof(float));
const uint8_t * restrict pb = ((const uint8_t *)x + 0*bs + 2*sizeof(float));
+#if defined(__AVX2__)
+ for (int i = 0; i < nb; i++) {
+ const __m256 d_v = _mm256_broadcast_ss((const float *) (pd + i*bs));
+ const __m256 d_m = _mm256_broadcast_ss((const float *) (pm + i*bs));
+
+ const uint8_t * restrict pp = pb + i*bs;
+
+ for (int l = 0; l < QK; l += 32) {
+ // Load 32x4-bit integers into 32x8-bit integers
+ __m256i vx8 = bytesFromNibbles(pp+l/2);
+
+ // Convert to 16-bit int
+ const __m256i vx16_lo = _mm256_cvtepi8_epi16(_mm256_extracti128_si256(vx8, 0));
+ const __m256i vx16_hi = _mm256_cvtepi8_epi16(_mm256_extracti128_si256(vx8, 1));
+
+ // Convert to 32-bit int -> float 32
+ const __m256 vf[4] = {
+ _mm256_cvtepi32_ps(_mm256_cvtepi16_epi32(_mm256_extracti128_si256(vx16_lo, 0))),
+ _mm256_cvtepi32_ps(_mm256_cvtepi16_epi32(_mm256_extracti128_si256(vx16_lo, 1))),
+ _mm256_cvtepi32_ps(_mm256_cvtepi16_epi32(_mm256_extracti128_si256(vx16_hi, 0))),
+ _mm256_cvtepi32_ps(_mm256_cvtepi16_epi32(_mm256_extracti128_si256(vx16_hi, 1)))
+ };
+
+ // Scale, add m and store
+ for (int j = 0; j < 4; j++) {
+ const __m256 result = _mm256_add_ps(_mm256_mul_ps(vf[j], d_v), d_m);
+ _mm256_storeu_ps(y + i * QK + l + j*8, result);
+ }
+ }
+ }
+#else
for (int i = 0; i < nb; i++) {
const float d = *(const float *) (pd + i*bs);
const float m = *(const float *) (pm + i*bs);
@@ -901,6 +932,7 @@ void dequantize_row_q4_1(const void * restrict x, float * restrict y, int k) {
assert(!isnan(y[i*QK + l + 1]));
}
}
+#endif
}
//