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Merged
ermig1979 merged 1 commit into from
Aug 24, 2026
Merged

Improve SVE2 optimizations of SimdFloat32ToBFloat16 #908

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1 change: 1 addition & 0 deletions docs/2026.html
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Original file line number Diff line number Diff line change
Expand Up @@ -113,6 +113,7 @@ <h5>Improving</h5>
<li>SVE2 optimizations of function GetObjectMoments.</li>
<li>SVE2 optimizations of function DescrIntCosineDistance.</li>
<li>SVE2 optimizations of function DescrIntCosineDistancesMxNa.</li>
<li>SVE2 optimizations of function Float32ToBFloat16.</li>
<li>C++ wrapper Simd::FillFrame.</li>
</ul>
<h5>Renaming</h5>
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23 changes: 14 additions & 9 deletions src/Simd/SimdSve2BFloat16.cpp
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Expand Up @@ -29,26 +29,31 @@ namespace Simd
#ifdef SIMD_SVE2_ENABLE
namespace Sve2
{
SIMD_INLINE svuint32_t Float32ToBFloat16(svfloat32_t value, const svbool_t& mask)
SIMD_INLINE svbfloat16_t Float32ToBFloat16(svfloat32_t even, svfloat32_t odd, const svbool_t& mask)
{
svuint32_t bits = svreinterpret_u32_f32(value);
svuint32_t round = svadd_n_u32_x(mask, svand_n_u32_x(mask, svlsr_n_u32_x(mask, bits, Base::Bf16::SHIFT), 1), Base::Bf16::ROUND);
return svlsr_n_u32_x(mask, svadd_u32_x(mask, bits, round), Base::Bf16::SHIFT);
return svcvtnt_bf16_f32_x(svcvt_bf16_f32_x(mask, even), mask, odd);
}

SIMD_INLINE void Float32ToBFloat16(const float* src, const svbool_t& lo, const svbool_t& hi, const svbool_t& store, uint16_t* dst)
{
size_t F = svlen(svfloat32_t());
svuint16_t _lo = svreinterpret_u16_u32(Float32ToBFloat16(svld1_f32(lo, src + 0), lo));
svuint16_t _hi = svreinterpret_u16_u32(Float32ToBFloat16(svld1_f32(hi, src + F), hi));
svst1_u16(store, dst, svuzp1_u16(_lo, _hi));
size_t F = svcntw();
svfloat32_t s0 = svld1_f32(lo, src + 0);
svfloat32_t s1 = svld1_f32(hi, src + F);
svst1_u16(store, dst, svreinterpret_u16_bf16(Float32ToBFloat16(svuzp1_f32(s0, s1), svuzp2_f32(s0, s1), svptrue_b32())));
}

void Float32ToBFloat16(const float* src, size_t size, uint16_t* dst)
{
size_t A = svlen(svuint16_t()), F = svlen(svfloat32_t()), sizeA = AlignLo(size, A), i = 0;
size_t A = svcnth(), F = svcntw(), QA = A * 4, sizeQA = AlignLo(size, QA), sizeA = AlignLo(size, A), i = 0;
const svbool_t body16 = svptrue_b16();
const svbool_t body32 = svptrue_b32();
for (; i < sizeQA; i += QA)
{
Float32ToBFloat16(src + i + 0 * A, body32, body32, body16, dst + i + 0 * A);
Float32ToBFloat16(src + i + 1 * A, body32, body32, body16, dst + i + 1 * A);
Float32ToBFloat16(src + i + 2 * A, body32, body32, body16, dst + i + 2 * A);
Float32ToBFloat16(src + i + 3 * A, body32, body32, body16, dst + i + 3 * A);
}
for (; i < sizeA; i += A)
Float32ToBFloat16(src + i, body32, body32, body16, dst + i);
if (i < size)
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