ggml: fixed Arm SVE usage bug in vec.h, vec.cpp (#22841)

* Updated vec.h/vec.cpp code to accumulate to F32 rather than F16



Change-Id: I0cb789347f2bf60ffaf9047319f727e788c825f8

Signed-off-by: Martin Klacer <martin.klacer@arm.com>
Co-authored-by: Milos Puzovic <Milos.Puzovic@arm.com>
This commit is contained in:
Martin Klacer
2026-05-28 10:04:21 +03:00
committed by GitHub
co-authored by Milos Puzovic
parent 491c4d7d2e
commit e31cdaa0eb
2 changed files with 105 additions and 139 deletions
+35 -51
View File
@@ -273,67 +273,51 @@ void ggml_vec_dot_f16(int n, float * GGML_RESTRICT s, size_t bs, ggml_fp16_t * G
#if defined(GGML_SIMD)
#if defined(__ARM_FEATURE_SVE)
const int sve_register_length = svcntb() * 8; //get vector length
const int ggml_f16_epr = sve_register_length / 16; // running when 16
const int ggml_f16_step = 8 * ggml_f16_epr; // choose 8 SVE registers
const int ggml_f16_epr = svcnth();
const int ggml_f16_step = 8 * ggml_f16_epr;
const int np = n - (n % ggml_f16_step);
const int np2 = n - (n % ggml_f16_epr);
const int np= (n & ~(ggml_f16_step - 1));
svfloat16_t sum1 = svdup_n_f16(0.0f);
svfloat16_t sum2 = svdup_n_f16(0.0f);
svfloat16_t sum3 = svdup_n_f16(0.0f);
svfloat16_t sum4 = svdup_n_f16(0.0f);
svfloat32_t sum1_lo = svdup_n_f32(0.0f);
svfloat32_t sum1_hi = svdup_n_f32(0.0f);
svfloat32_t sum2_lo = svdup_n_f32(0.0f);
svfloat32_t sum2_hi = svdup_n_f32(0.0f);
svfloat32_t sum3_lo = svdup_n_f32(0.0f);
svfloat32_t sum3_hi = svdup_n_f32(0.0f);
svfloat32_t sum4_lo = svdup_n_f32(0.0f);
svfloat32_t sum4_hi = svdup_n_f32(0.0f);
svfloat16_t ax1, ax2, ax3, ax4, ax5, ax6, ax7, ax8;
svfloat16_t ay1, ay2, ay3, ay4, ay5, ay6, ay7, ay8;
for (int i = 0; i < np; i += ggml_f16_step) {
ax1 = GGML_F16x_VEC_LOAD(x + i + 0 * ggml_f16_epr, 0);
ay1 = GGML_F16x_VEC_LOAD(y + i + 0 * ggml_f16_epr, 0);
sum1 = GGML_F16x_VEC_FMA(sum1, ax1, ay1);
ax2 = GGML_F16x_VEC_LOAD(x + i + 1 * ggml_f16_epr, 1);
ay2 = GGML_F16x_VEC_LOAD(y + i + 1 * ggml_f16_epr, 1);
sum2 = GGML_F16x_VEC_FMA(sum2, ax2, ay2);
ax3 = GGML_F16x_VEC_LOAD(x + i + 2 * ggml_f16_epr, 2);
ay3 = GGML_F16x_VEC_LOAD(y + i + 2 * ggml_f16_epr, 2);
sum3 = GGML_F16x_VEC_FMA(sum3, ax3, ay3);
ax4 = GGML_F16x_VEC_LOAD(x + i + 3 * ggml_f16_epr, 3);
ay4 = GGML_F16x_VEC_LOAD(y + i + 3 * ggml_f16_epr, 3);
sum4 = GGML_F16x_VEC_FMA(sum4, ax4, ay4);
ax5 = GGML_F16x_VEC_LOAD(x + i + 4 * ggml_f16_epr, 4);
ay5 = GGML_F16x_VEC_LOAD(y + i + 4 * ggml_f16_epr, 4);
sum1 = GGML_F16x_VEC_FMA(sum1, ax5, ay5);
ax6 = GGML_F16x_VEC_LOAD(x + i + 5 * ggml_f16_epr, 5);
ay6 = GGML_F16x_VEC_LOAD(y + i + 5 * ggml_f16_epr, 5);
sum2 = GGML_F16x_VEC_FMA(sum2, ax6, ay6);
ax7 = GGML_F16x_VEC_LOAD(x + i + 6 * ggml_f16_epr, 6);
ay7 = GGML_F16x_VEC_LOAD(y + i + 6 * ggml_f16_epr, 6);
sum3 = GGML_F16x_VEC_FMA(sum3, ax7, ay7);
ax8 = GGML_F16x_VEC_LOAD(x + i + 7 * ggml_f16_epr, 7);
ay8 = GGML_F16x_VEC_LOAD(y + i + 7 * ggml_f16_epr, 7);
sum4 = GGML_F16x_VEC_FMA(sum4, ax8, ay8);
ggml_sve_f16_fma_widened(&sum1_lo, &sum1_hi, GGML_F16x_VEC_LOAD(x + i + 0 * ggml_f16_epr, 0), GGML_F16x_VEC_LOAD(y + i + 0 * ggml_f16_epr, 0));
ggml_sve_f16_fma_widened(&sum2_lo, &sum2_hi, GGML_F16x_VEC_LOAD(x + i + 1 * ggml_f16_epr, 1), GGML_F16x_VEC_LOAD(y + i + 1 * ggml_f16_epr, 1));
ggml_sve_f16_fma_widened(&sum3_lo, &sum3_hi, GGML_F16x_VEC_LOAD(x + i + 2 * ggml_f16_epr, 2), GGML_F16x_VEC_LOAD(y + i + 2 * ggml_f16_epr, 2));
ggml_sve_f16_fma_widened(&sum4_lo, &sum4_hi, GGML_F16x_VEC_LOAD(x + i + 3 * ggml_f16_epr, 3), GGML_F16x_VEC_LOAD(y + i + 3 * ggml_f16_epr, 3));
ggml_sve_f16_fma_widened(&sum1_lo, &sum1_hi, GGML_F16x_VEC_LOAD(x + i + 4 * ggml_f16_epr, 4), GGML_F16x_VEC_LOAD(y + i + 4 * ggml_f16_epr, 4));
ggml_sve_f16_fma_widened(&sum2_lo, &sum2_hi, GGML_F16x_VEC_LOAD(x + i + 5 * ggml_f16_epr, 5), GGML_F16x_VEC_LOAD(y + i + 5 * ggml_f16_epr, 5));
ggml_sve_f16_fma_widened(&sum3_lo, &sum3_hi, GGML_F16x_VEC_LOAD(x + i + 6 * ggml_f16_epr, 6), GGML_F16x_VEC_LOAD(y + i + 6 * ggml_f16_epr, 6));
ggml_sve_f16_fma_widened(&sum4_lo, &sum4_hi, GGML_F16x_VEC_LOAD(x + i + 7 * ggml_f16_epr, 7), GGML_F16x_VEC_LOAD(y + i + 7 * ggml_f16_epr, 7));
}
const int np2 = (n & ~(ggml_f16_epr - 1)); // round down to multiple of 8
for (int k = np; k < np2; k += ggml_f16_epr) {
svfloat16_t rx = GGML_F16x_VEC_LOAD(x + k, 0);
svfloat16_t ry = GGML_F16x_VEC_LOAD(y + k, 0);
sum1 = GGML_F16x_VEC_FMA(sum1, rx, ry);
for (int i = np; i < np2; i += ggml_f16_epr) {
ggml_sve_f16_fma_widened(&sum1_lo, &sum1_hi, GGML_F16x_VEC_LOAD(x + i, 0), GGML_F16x_VEC_LOAD(y + i, 0));
}
if (np2 < n) {
svbool_t pg = svwhilelt_b16(np2, n);
svfloat16_t hx = svld1_f16(pg, (const __fp16 *)(x + np2));
svfloat16_t hy = svld1_f16(pg, (const __fp16 *)(y + np2));
const svbool_t pg = svwhilelt_b16(np2, n);
const svfloat16_t rx = svld1_f16(pg, (const __fp16 *)(x + np2));
const svfloat16_t ry = svld1_f16(pg, (const __fp16 *)(y + np2));
sum1 = svmad_f16_x(pg, hx, hy, sum1);
ggml_sve_f16_fma_widened(&sum1_lo, &sum1_hi, rx, ry);
}
GGML_F16x_VEC_REDUCE(sumf, sum1, sum2, sum3, sum4);
sum1_lo = svadd_f32_m(DEFAULT_PG32, sum1_lo, sum2_lo);
sum1_hi = svadd_f32_m(DEFAULT_PG32, sum1_hi, sum2_hi);
sum3_lo = svadd_f32_m(DEFAULT_PG32, sum3_lo, sum4_lo);
sum3_hi = svadd_f32_m(DEFAULT_PG32, sum3_hi, sum4_hi);
sum1_lo = svadd_f32_m(DEFAULT_PG32, sum1_lo, sum3_lo);
sum1_hi = svadd_f32_m(DEFAULT_PG32, sum1_hi, sum3_hi);
sumf = ggml_sve_sum_f32x2(sum1_lo, sum1_hi);
#elif defined(__riscv_v_intrinsic)
#if defined(__riscv_zvfh)
int vl = __riscv_vsetvlmax_e32m2();