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vulkan: Block-load Q3_K/Q6_K block data and subtract on 32b ints #23056

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Merged
0cc4m merged 1 commit into from
Jun 1, 2026
Merged

vulkan: Block-load Q3_K/Q6_K block data and subtract on 32b ints #23056

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19 changes: 14 additions & 5 deletions ggml/src/ggml-vulkan/ggml-vulkan.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -7844,8 +7844,10 @@ static bool ggml_vk_should_use_mmvq(const vk_device& device, uint32_t m, uint32_
return false;
}

// General performance issue with q3_k and q6_k due to 2-byte alignment
if (src0_type == GGML_TYPE_Q3_K || src0_type == GGML_TYPE_Q6_K) {
// q6_k only has 2-byte alignment which makes it somewhat problematic,
// using MMVQ is only a win on Intel.
bool mmvq_q6 = device->vendor_id == VK_VENDOR_ID_INTEL;
if (src0_type == GGML_TYPE_Q6_K && !mmvq_q6) {
return false;
}

Expand All @@ -7857,7 +7859,7 @@ static bool ggml_vk_should_use_mmvq(const vk_device& device, uint32_t m, uint32_
// Quantization overhead is not worth it for small k
switch (device->vendor_id) {
case VK_VENDOR_ID_NVIDIA:
if (src0_type == GGML_TYPE_Q2_K || src0_type == GGML_TYPE_IQ1_S || src0_type == GGML_TYPE_IQ1_M) {
if (src0_type == GGML_TYPE_Q2_K || src0_type == GGML_TYPE_Q3_K || src0_type == GGML_TYPE_IQ1_S || src0_type == GGML_TYPE_IQ1_M) {
return true;
}

Expand All @@ -7884,9 +7886,16 @@ static bool ggml_vk_should_use_mmvq(const vk_device& device, uint32_t m, uint32_
return true;
}
case VK_VENDOR_ID_INTEL:
if (device->architecture == vk_device_architecture::INTEL_XE2) {
if (src0_type == GGML_TYPE_Q2_K || src0_type == GGML_TYPE_Q3_K || src0_type == GGML_TYPE_Q6_K) {
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return true;
}
}

if (device->driver_id == vk::DriverId::eIntelProprietaryWindows) {
// Intel Windows proprietary driver MMVQ performance is worse than fp16, see
// https://github.com/ggml-org/llama.cpp/issues/17628
// Intel Windows proprietary driver MMVQ performance for !Q2/Q3/Q6 is worse than fp16,
// see https://github.com/ggml-org/llama.cpp/issues/17628 and
// https://github.com/ggml-org/llama.cpp/pull/23056
return false;
}

Expand Down
108 changes: 66 additions & 42 deletions ggml/src/ggml-vulkan/vulkan-shaders/mul_mat_vecq_funcs.glsl
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Original file line number Diff line number Diff line change
Expand Up @@ -212,28 +212,40 @@ i32vec4 repack4(uint ib, uint iqs) {
const uint qs_shift = ((iqs_k % 32) / 8) * 2;
const uint hm_shift = iqs_k / 8;

const uvec4 qs = uvec4( uint32_t(data_a_packed16[ib_k].qs[qs_idx * 2 ]) |
(uint32_t(data_a_packed16[ib_k].qs[qs_idx * 2 + 1]) << 16),
uint32_t(data_a_packed16[ib_k].qs[qs_idx * 2 + 2]) |
(uint32_t(data_a_packed16[ib_k].qs[qs_idx * 2 + 3]) << 16),
uint32_t(data_a_packed16[ib_k].qs[qs_idx * 2 + 4]) |
(uint32_t(data_a_packed16[ib_k].qs[qs_idx * 2 + 5]) << 16),
uint32_t(data_a_packed16[ib_k].qs[qs_idx * 2 + 6]) |
(uint32_t(data_a_packed16[ib_k].qs[qs_idx * 2 + 7]) << 16));

const uvec4 hmask = uvec4( uint32_t(data_a_packed16[ib_k].hmask[iqs * 2 ]) |
(uint32_t(data_a_packed16[ib_k].hmask[iqs * 2 + 1]) << 16),
uint32_t(data_a_packed16[ib_k].hmask[iqs * 2 + 2]) |
(uint32_t(data_a_packed16[ib_k].hmask[iqs * 2 + 3]) << 16),
uint32_t(data_a_packed16[ib_k].hmask[iqs * 2 + 4]) |
(uint32_t(data_a_packed16[ib_k].hmask[iqs * 2 + 5]) << 16),
uint32_t(data_a_packed16[ib_k].hmask[iqs * 2 + 6]) |
(uint32_t(data_a_packed16[ib_k].hmask[iqs * 2 + 7]) << 16));

// bitwise OR to add 4 if hmask is set, subtract later
const i8vec2 vals00 = unpack8(int16_t((data_a_packed16[ib_k].qs[qs_idx * 2 ] >> qs_shift) & uint16_t(0x0303))) |
unpack8(int16_t(((data_a_packed16[ib_k].hmask[iqs * 2 ] >> hm_shift) & uint16_t(0x0101)) << 2));
const i8vec2 vals01 = unpack8(int16_t((data_a_packed16[ib_k].qs[qs_idx * 2 + 1] >> qs_shift) & uint16_t(0x0303))) |
unpack8(int16_t(((data_a_packed16[ib_k].hmask[iqs * 2 + 1] >> hm_shift) & uint16_t(0x0101)) << 2));
const i8vec2 vals10 = unpack8(int16_t((data_a_packed16[ib_k].qs[qs_idx * 2 + 2] >> qs_shift) & uint16_t(0x0303))) |
unpack8(int16_t(((data_a_packed16[ib_k].hmask[iqs * 2 + 2] >> hm_shift) & uint16_t(0x0101)) << 2));
const i8vec2 vals11 = unpack8(int16_t((data_a_packed16[ib_k].qs[qs_idx * 2 + 3] >> qs_shift) & uint16_t(0x0303))) |
unpack8(int16_t(((data_a_packed16[ib_k].hmask[iqs * 2 + 3] >> hm_shift) & uint16_t(0x0101)) << 2));
const i8vec2 vals20 = unpack8(int16_t((data_a_packed16[ib_k].qs[qs_idx * 2 + 4] >> qs_shift) & uint16_t(0x0303))) |
unpack8(int16_t(((data_a_packed16[ib_k].hmask[iqs * 2 + 4] >> hm_shift) & uint16_t(0x0101)) << 2));
const i8vec2 vals21 = unpack8(int16_t((data_a_packed16[ib_k].qs[qs_idx * 2 + 5] >> qs_shift) & uint16_t(0x0303))) |
unpack8(int16_t(((data_a_packed16[ib_k].hmask[iqs * 2 + 5] >> hm_shift) & uint16_t(0x0101)) << 2));
const i8vec2 vals30 = unpack8(int16_t((data_a_packed16[ib_k].qs[qs_idx * 2 + 6] >> qs_shift) & uint16_t(0x0303))) |
unpack8(int16_t(((data_a_packed16[ib_k].hmask[iqs * 2 + 6] >> hm_shift) & uint16_t(0x0101)) << 2));
const i8vec2 vals31 = unpack8(int16_t((data_a_packed16[ib_k].qs[qs_idx * 2 + 7] >> qs_shift) & uint16_t(0x0303))) |
unpack8(int16_t(((data_a_packed16[ib_k].hmask[iqs * 2 + 7] >> hm_shift) & uint16_t(0x0101)) << 2));

return i32vec4(pack32(i8vec4(vals00.x, vals00.y, vals01.x, vals01.y) - int8_t(4)),
pack32(i8vec4(vals10.x, vals10.y, vals11.x, vals11.y) - int8_t(4)),
pack32(i8vec4(vals20.x, vals20.y, vals21.x, vals21.y) - int8_t(4)),
pack32(i8vec4(vals30.x, vals30.y, vals31.x, vals31.y) - int8_t(4)));
const uint vals0 = (( qs.x >> qs_shift) & 0x03030303) |
(((hmask.x >> hm_shift) & 0x01010101) << 2);
const uint vals1 = (( qs.y >> qs_shift) & 0x03030303) |
(((hmask.y >> hm_shift) & 0x01010101) << 2);
const uint vals2 = (( qs.z >> qs_shift) & 0x03030303) |
(((hmask.z >> hm_shift) & 0x01010101) << 2);
const uint vals3 = (( qs.w >> qs_shift) & 0x03030303) |
(((hmask.w >> hm_shift) & 0x01010101) << 2);

// Subtract 4 by twiddling bits rather than using re-packing as mesa
// compiles repacking poorly.
return i32vec4(int32_t(((vals0 ^ 0x80808080) - 0x04040404) ^ 0x80808080),
int32_t(((vals1 ^ 0x80808080) - 0x04040404) ^ 0x80808080),
int32_t(((vals2 ^ 0x80808080) - 0x04040404) ^ 0x80808080),
int32_t(((vals3 ^ 0x80808080) - 0x04040404) ^ 0x80808080));
}

float get_d_scale(uint ib, uint iqs) {
Expand Down Expand Up @@ -343,27 +355,39 @@ i32vec4 repack4(uint ib, uint iqs) {
const uint qh_idx = (iqs_k / 32) * 8 + iqs;
const uint qh_shift = ((iqs_k % 32) / 8) * 2;

const i8vec2 vals00 = (unpack8(int16_t((data_a_packed16[ib_k].ql[ql_idx * 2 ] >> ql_shift) & uint16_t(0x0F0F))) |
unpack8(int16_t(((data_a_packed16[ib_k].qh[qh_idx * 2 ] >> qh_shift) & uint16_t(0x0303)) << 4))) - int8_t(32);
const i8vec2 vals01 = (unpack8(int16_t((data_a_packed16[ib_k].ql[ql_idx * 2 + 1] >> ql_shift) & uint16_t(0x0F0F))) |
unpack8(int16_t(((data_a_packed16[ib_k].qh[qh_idx * 2 + 1] >> qh_shift) & uint16_t(0x0303)) << 4))) - int8_t(32);
const i8vec2 vals10 = (unpack8(int16_t((data_a_packed16[ib_k].ql[ql_idx * 2 + 2] >> ql_shift) & uint16_t(0x0F0F))) |
unpack8(int16_t(((data_a_packed16[ib_k].qh[qh_idx * 2 + 2] >> qh_shift) & uint16_t(0x0303)) << 4))) - int8_t(32);
const i8vec2 vals11 = (unpack8(int16_t((data_a_packed16[ib_k].ql[ql_idx * 2 + 3] >> ql_shift) & uint16_t(0x0F0F))) |
unpack8(int16_t(((data_a_packed16[ib_k].qh[qh_idx * 2 + 3] >> qh_shift) & uint16_t(0x0303)) << 4))) - int8_t(32);
const i8vec2 vals20 = (unpack8(int16_t((data_a_packed16[ib_k].ql[ql_idx * 2 + 4] >> ql_shift) & uint16_t(0x0F0F))) |
unpack8(int16_t(((data_a_packed16[ib_k].qh[qh_idx * 2 + 4] >> qh_shift) & uint16_t(0x0303)) << 4))) - int8_t(32);
const i8vec2 vals21 = (unpack8(int16_t((data_a_packed16[ib_k].ql[ql_idx * 2 + 5] >> ql_shift) & uint16_t(0x0F0F))) |
unpack8(int16_t(((data_a_packed16[ib_k].qh[qh_idx * 2 + 5] >> qh_shift) & uint16_t(0x0303)) << 4))) - int8_t(32);
const i8vec2 vals30 = (unpack8(int16_t((data_a_packed16[ib_k].ql[ql_idx * 2 + 6] >> ql_shift) & uint16_t(0x0F0F))) |
unpack8(int16_t(((data_a_packed16[ib_k].qh[qh_idx * 2 + 6] >> qh_shift) & uint16_t(0x0303)) << 4))) - int8_t(32);
const i8vec2 vals31 = (unpack8(int16_t((data_a_packed16[ib_k].ql[ql_idx * 2 + 7] >> ql_shift) & uint16_t(0x0F0F))) |
unpack8(int16_t(((data_a_packed16[ib_k].qh[qh_idx * 2 + 7] >> qh_shift) & uint16_t(0x0303)) << 4))) - int8_t(32);

return i32vec4(pack32(i8vec4(vals00.x, vals00.y, vals01.x, vals01.y)),
pack32(i8vec4(vals10.x, vals10.y, vals11.x, vals11.y)),
pack32(i8vec4(vals20.x, vals20.y, vals21.x, vals21.y)),
pack32(i8vec4(vals30.x, vals30.y, vals31.x, vals31.y)));
const uvec4 ql = uvec4( uint32_t(data_a_packed16[ib_k].ql[ql_idx * 2 ]) |
(uint32_t(data_a_packed16[ib_k].ql[ql_idx * 2 + 1]) << 16),
uint32_t(data_a_packed16[ib_k].ql[ql_idx * 2 + 2]) |
(uint32_t(data_a_packed16[ib_k].ql[ql_idx * 2 + 3]) << 16),
uint32_t(data_a_packed16[ib_k].ql[ql_idx * 2 + 4]) |
(uint32_t(data_a_packed16[ib_k].ql[ql_idx * 2 + 5]) << 16),
uint32_t(data_a_packed16[ib_k].ql[ql_idx * 2 + 6]) |
(uint32_t(data_a_packed16[ib_k].ql[ql_idx * 2 + 7]) << 16));

const uvec4 qh = uvec4( uint32_t(data_a_packed16[ib_k].qh[qh_idx * 2 ]) |
(uint32_t(data_a_packed16[ib_k].qh[qh_idx * 2 + 1]) << 16),
uint32_t(data_a_packed16[ib_k].qh[qh_idx * 2 + 2]) |
(uint32_t(data_a_packed16[ib_k].qh[qh_idx * 2 + 3]) << 16),
uint32_t(data_a_packed16[ib_k].qh[qh_idx * 2 + 4]) |
(uint32_t(data_a_packed16[ib_k].qh[qh_idx * 2 + 5]) << 16),
uint32_t(data_a_packed16[ib_k].qh[qh_idx * 2 + 6]) |
(uint32_t(data_a_packed16[ib_k].qh[qh_idx * 2 + 7]) << 16));

const uint vals0 = (( ql.x >> ql_shift) & 0x0F0F0F0F) |
(((qh.x >> qh_shift) & 0x03030303) << 4);
const uint vals1 = (( ql.y >> ql_shift) & 0x0F0F0F0F) |
(((qh.y >> qh_shift) & 0x03030303) << 4);
const uint vals2 = (( ql.z >> ql_shift) & 0x0F0F0F0F) |
(((qh.z >> qh_shift) & 0x03030303) << 4);
const uint vals3 = (( ql.w >> ql_shift) & 0x0F0F0F0F) |
(((qh.w >> qh_shift) & 0x03030303) << 4);

// Subtract 32 by twiddling bits rather than using re-packing as mesa
// compiles repacking poorly.
return i32vec4(int32_t(((vals0 ^ 0x80808080) - 0x20202020) ^ 0x80808080),
int32_t(((vals1 ^ 0x80808080) - 0x20202020) ^ 0x80808080),
int32_t(((vals2 ^ 0x80808080) - 0x20202020) ^ 0x80808080),
int32_t(((vals3 ^ 0x80808080) - 0x20202020) ^ 0x80808080));
}

float get_d_scale(uint ib, uint iqs) {
Expand Down
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