kleidiai: add optimized per-channel kernels for Q8_0 (#16993)

This commit is contained in:
Charles Xu
2025-11-11 13:20:31 +02:00
committed by GitHub
parent 4a5b8aff40
commit 8c583242ad
4 changed files with 538 additions and 41 deletions
+239 -38
View File
@@ -5,10 +5,13 @@
#include <assert.h>
#include <atomic>
#include <cfloat>
#include <cmath>
#include <algorithm>
#include <stdexcept>
#include <stdint.h>
#include <string.h>
#include <string>
#include <vector>
#if defined(__linux__)
#include <asm/hwcap.h>
#include <sys/auxv.h>
@@ -38,8 +41,9 @@
struct ggml_kleidiai_context {
cpu_feature features;
ggml_kleidiai_kernels * kernels;
} static ctx = { CPU_FEATURE_NONE, NULL };
ggml_kleidiai_kernels * kernels_q4;
ggml_kleidiai_kernels * kernels_q8;
} static ctx = { CPU_FEATURE_NONE, NULL, NULL };
static const char* cpu_feature_to_string(cpu_feature f) {
switch (f) {
@@ -73,10 +77,14 @@ static void init_kleidiai_context(void) {
if (sme_enabled != 0) {
ctx.features |= ggml_cpu_has_sme() ? CPU_FEATURE_SME : CPU_FEATURE_NONE;
}
ctx.kernels = ggml_kleidiai_select_kernels_q4_0(ctx.features);
ctx.kernels_q4 = ggml_kleidiai_select_kernels_q4_0(ctx.features);
ctx.kernels_q8 = ggml_kleidiai_select_kernels_q8_0(ctx.features);
#ifndef NDEBUG
if (ctx.kernels) {
GGML_LOG_DEBUG("kleidiai: using kernel with CPU feature %s\n", cpu_feature_to_string(ctx.kernels->required_cpu));
if (ctx.kernels_q4) {
GGML_LOG_DEBUG("kleidiai: using q4 kernel with CPU feature %s\n", cpu_feature_to_string(ctx.kernels_q4->required_cpu));
}
if (ctx.kernels_q8) {
GGML_LOG_DEBUG("kleidiai: using q8 kernel with CPU feature %s\n", cpu_feature_to_string(ctx.kernels_q8->required_cpu));
}
#endif
}
@@ -130,6 +138,9 @@ class tensor_traits : public ggml::cpu::tensor_traits {
if (kernels->rhs_type == GGML_TYPE_Q4_0) {
if (!lhs_info->packed_size_ex) return false;
size = lhs_info->packed_size_ex(m, k, QK4_0, mr, kr, sr);
} else if (kernels->rhs_type == GGML_TYPE_Q8_0) {
if (!lhs_info->packed_size_ex) return false;
size = lhs_info->packed_size_ex(m, k, QK8_0, mr, kr, sr);
} else if (kernels->rhs_type == GGML_TYPE_F16) {
if (!lhs_info->packed_size_ex || !kernels->rhs_info.packed_size_ex) return false;
const int64_t lhs_batch_size0 = op->src[1]->ne[2];
@@ -149,11 +160,13 @@ class tensor_traits : public ggml::cpu::tensor_traits {
if (dst->op == GGML_OP_MUL_MAT) {
if (dst->src[0]->type == GGML_TYPE_Q4_0) {
return compute_forward_q4_0(params, dst);
} else if (dst->src[0]->type == GGML_TYPE_Q8_0) {
return compute_forward_q8_0(params, dst);
} else if (dst->src[0]->type == GGML_TYPE_F16) {
return compute_forward_fp16(params, dst);
}
} else if (dst->op == GGML_OP_GET_ROWS) {
if (dst->src[0]->type == GGML_TYPE_Q4_0) {
if (dst->src[0]->type == GGML_TYPE_Q4_0 || dst->src[0]->type == GGML_TYPE_Q8_0) {
return compute_forward_get_rows(params, dst);
}
}
@@ -400,19 +413,120 @@ class tensor_traits : public ggml::cpu::tensor_traits {
return true;
}
bool compute_forward_get_rows(struct ggml_compute_params * params, struct ggml_tensor * dst) {
GGML_ASSERT(dst->src[0]->type == GGML_TYPE_Q4_0);
if (!ctx.kernels) {
return false;
}
bool compute_forward_q8_0(struct ggml_compute_params * params, struct ggml_tensor * dst) {
GGML_ASSERT(dst->src[0]->type == GGML_TYPE_Q8_0);
const ggml_tensor * src0 = dst->src[0];
const ggml_tensor * src1 = dst->src[1];
GGML_TENSOR_BINARY_OP_LOCALS
rhs_packing_info * rhs_info = &ctx.kernels->rhs_info;
kernel_info * kernel = &ctx.kernels->gemm;
ggml_kleidiai_kernels *kernels = ggml_kleidiai_select_kernels(ctx.features, dst);
if (!kernels) {
return false;
}
bool is_gemv = src1->ne[1] == 1;
kernel_info * kernel = is_gemv ? &kernels->gemv : &kernels->gemm;
lhs_packing_info * lhs_info = is_gemv ? &kernels->gemv_lhs_info : &kernels->gemm_lhs_info;
if (!kernel || !lhs_info->get_packed_offset_ex || !lhs_info->pack_func_ex ||
!kernel->get_rhs_packed_offset_ex || !kernel->run_kernel_ex || !kernel->get_dst_offset) {
return false;
}
const int ith = params->ith;
const int nth_raw = params->nth;
const int nth = nth_raw > 0 ? nth_raw : 1;
const size_t k = ne00;
const size_t m = ne11;
const size_t n = ne01;
size_t mr = kernel->get_mr();
size_t kr = kernel->get_kr();
size_t sr = kernel->get_sr();
const uint8_t * lhs = static_cast<const uint8_t *>(src1->data);
uint8_t * lhs_packed = static_cast<uint8_t *>(params->wdata);
const uint8_t * rhs_packed = static_cast<const uint8_t *>(src0->data);
const size_t n_step = kernel->get_n_step();
const size_t num_n_per_thread = kai_roundup(kai_roundup(n, nth) / nth, n_step);
const size_t n_start = ith * num_n_per_thread;
size_t n_to_process = 0;
if (n_start < n) {
n_to_process = num_n_per_thread;
if ((n_start + n_to_process) > n) {
n_to_process = n - n_start;
}
}
const size_t num_m_per_thread = kai_roundup(m, mr * nth) / nth;
const size_t m_start = ith * num_m_per_thread;
size_t m_to_process = num_m_per_thread;
if ((m_start + m_to_process) > m) {
m_to_process = m - m_start;
}
if (m_start < m) {
const size_t src_stride = src1->nb[1];
const float * src_ptr = reinterpret_cast<const float *>(lhs + lhs_info->get_offset(m_start, dst->src[1]->nb[1]));
const size_t lhs_packed_offset = lhs_info->get_packed_offset_ex(m_start, k, 0, mr, kr, sr);
void * lhs_packed_ptr = static_cast<void *>(lhs_packed + lhs_packed_offset);
lhs_info->pack_func_ex(m_to_process, k, 0, mr, kr, sr, 0, src_ptr, src_stride, lhs_packed_ptr);
}
ggml_barrier(params->threadpool);
const size_t dst_stride = dst->nb[1];
const size_t lhs_packed_offset = lhs_info->get_packed_offset_ex(0, k, 0, mr, kr, sr);
const size_t rhs_packed_offset = kernel->get_rhs_packed_offset_ex(n_start, k, 0);
const size_t dst_offset = kernel->get_dst_offset(0, n_start, dst_stride);
const void * rhs_ptr = static_cast<const void *>(rhs_packed + rhs_packed_offset);
const void * lhs_ptr = static_cast<const void *>(lhs_packed + lhs_packed_offset);
float * dst_ptr = reinterpret_cast<float *>(static_cast<uint8_t *>(dst->data) + dst_offset);
if (n_to_process > 0) {
kernel->run_kernel_ex(m, n_to_process, k, 0, lhs_ptr, rhs_ptr, dst_ptr, dst_stride,
sizeof(float), -FLT_MAX, FLT_MAX);
}
return true;
}
bool compute_forward_get_rows(struct ggml_compute_params * params, struct ggml_tensor * dst) {
const ggml_tensor * src0 = dst->src[0];
const ggml_tensor * src1 = dst->src[1];
GGML_TENSOR_BINARY_OP_LOCALS
ggml_kleidiai_kernels * kernels = nullptr;
size_t block_len = 0;
size_t num_bytes_multiplier = 0;
if (dst->src[0]->type == GGML_TYPE_Q4_0) {
if (!ctx.kernels_q4) {
return false;
}
kernels = ctx.kernels_q4;
block_len = QK4_0;
num_bytes_multiplier = sizeof(uint16_t);
} else if (dst->src[0]->type == GGML_TYPE_Q8_0) {
if (!ctx.kernels_q8) {
return false;
}
kernels = ctx.kernels_q8;
block_len = QK8_0;
num_bytes_multiplier = sizeof(float);
} else {
return false;
}
rhs_packing_info * rhs_info = &kernels->rhs_info;
kernel_info * kernel = &kernels->gemm;
if (!rhs_info->to_float || !kernel->get_nr) {
return false;
}
@@ -423,8 +537,7 @@ class tensor_traits : public ggml::cpu::tensor_traits {
const size_t block_rows = kernel->get_nr();
const size_t kr = kernel->get_kr();
const size_t num_bytes_multiplier = sizeof(uint16_t);
const size_t packed_stride = rhs_info->packed_stride(nc, block_rows, kr, QK4_0);
const size_t packed_stride = rhs_info->packed_stride(nc, block_rows, kr, block_len);
const int ith = params->ith;
const int nth = params->nth;
@@ -439,7 +552,7 @@ class tensor_traits : public ggml::cpu::tensor_traits {
GGML_ASSERT(row_idx >= 0 && row_idx < src0->ne[1]);
float *out = (float *)((char *)dst->data + i * nb1);
rhs_info->to_float(src0->data, row_idx, nc, out, block_rows, packed_stride, kr, QK4_0, num_bytes_multiplier);
rhs_info->to_float(src0->data, row_idx, nc, out, block_rows, packed_stride, kr, block_len, num_bytes_multiplier);
}
return true;
@@ -447,21 +560,91 @@ class tensor_traits : public ggml::cpu::tensor_traits {
public:
int repack(struct ggml_tensor * tensor, const void * data, size_t data_size) {
GGML_ASSERT(tensor->type == GGML_TYPE_Q4_0);
GGML_ASSERT(ctx.kernels);
const size_t n = tensor->ne[1];
const size_t k = tensor->ne[0];
size_t nr = ctx.kernels->gemm.get_nr();
size_t kr = ctx.kernels->gemm.get_kr();
size_t sr = ctx.kernels->gemm.get_sr();
struct kai_rhs_pack_qs4cxs1s0_param params;
params.lhs_zero_point = 1;
params.rhs_zero_point = 8;
ctx.kernels->rhs_info.pack_func_ex(1, n, k, nr, kr, sr, QK4_0, 0, (const uint8_t*)data, nullptr, nullptr, tensor->data, 0, &params);
if (tensor->type == GGML_TYPE_Q4_0) {
if (!ctx.kernels_q4) {
return -1;
}
size_t nr = ctx.kernels_q4->gemm.get_nr();
size_t kr = ctx.kernels_q4->gemm.get_kr();
size_t sr = ctx.kernels_q4->gemm.get_sr();
struct kai_rhs_pack_qs4cxs1s0_param params;
params.lhs_zero_point = 1;
params.rhs_zero_point = 8;
ctx.kernels_q4->rhs_info.pack_func_ex(1, n, k, nr, kr, sr, QK4_0, 0,
static_cast<const uint8_t *>(data),
nullptr, nullptr, tensor->data, 0, &params);
GGML_UNUSED(data_size);
return 0;
} else if (tensor->type == GGML_TYPE_Q8_0) {
if (!ctx.kernels_q8) {
return -1;
}
const size_t row_stride = tensor->nb[1];
const size_t k_blocks = (k + QK8_0 - 1) / QK8_0;
std::vector<int8_t> qdata(n * k, 0);
std::vector<float> scales(n, 0.0f);
for (size_t row = 0; row < n; ++row) {
const auto * row_blocks = reinterpret_cast<const block_q8_0 *>(
static_cast<const uint8_t *>(data) + row * row_stride);
float max_abs = 0.0f;
for (size_t block = 0; block < k_blocks; ++block) {
const block_q8_0 & blk = row_blocks[block];
const float d = GGML_FP16_TO_FP32(blk.d);
for (size_t l = 0; l < QK8_0; ++l) {
const size_t linear_idx = block * QK8_0 + l;
if (linear_idx >= k) {
break;
}
const float value = d * blk.qs[l];
max_abs = std::max(max_abs, std::fabs(value));
}
}
float scale = max_abs > 0.0f ? max_abs / 127.0f : 0.0f;
scales[row] = scale;
const float inv_scale = scale > 0.0f ? 1.0f / scale : 0.0f;
for (size_t block = 0; block < k_blocks; ++block) {
const block_q8_0 & blk = row_blocks[block];
const float d = GGML_FP16_TO_FP32(blk.d);
for (size_t l = 0; l < QK8_0; ++l) {
const size_t linear_idx = block * QK8_0 + l;
if (linear_idx >= k) {
break;
}
const float value = d * blk.qs[l];
int32_t q = scale > 0.0f ? static_cast<int32_t>(std::lround(value * inv_scale)) : 0;
q = std::clamp(q, -127, 127);
qdata[row * k + linear_idx] = static_cast<int8_t>(q);
}
}
}
size_t nr = ctx.kernels_q8->gemm.get_nr();
size_t kr = ctx.kernels_q8->gemm.get_kr();
size_t sr = ctx.kernels_q8->gemm.get_sr();
struct kai_rhs_pack_qsi8cx_params params;
params.lhs_zero_point = 1;
params.scale_multiplier = 1.0f;
ctx.kernels_q8->rhs_info.pack_func_ex(1, n, k, nr, kr, sr, 0, 0,
qdata.data(), nullptr, scales.data(),
tensor->data, 0, &params);
GGML_UNUSED(data_size);
return 0;
}
return 0;
GGML_UNUSED(data_size);
return -1;
}
};
@@ -518,27 +701,45 @@ static size_t ggml_backend_cpu_kleidiai_buffer_type_get_alignment(ggml_backend_b
}
static size_t ggml_backend_cpu_kleidiai_buffer_type_get_alloc_size(ggml_backend_buffer_type_t buft, const struct ggml_tensor * tensor) {
GGML_ASSERT(tensor->type == GGML_TYPE_Q4_0);
GGML_ASSERT(ctx.kernels);
const size_t n = tensor->ne[1];
const size_t k = tensor->ne[0];
const size_t nr = ctx.kernels->gemm.get_nr();
const size_t kr = ctx.kernels->gemm.get_kr();
return ctx.kernels->rhs_info.packed_size_ex(n, k, nr, kr, QK4_0);
GGML_UNUSED(buft);
const size_t n = tensor->ne[1];
const size_t k = tensor->ne[0];
ggml_kleidiai_kernels * kernels = nullptr;
size_t block_len = 0;
if (tensor->type == GGML_TYPE_Q4_0) {
GGML_ASSERT(ctx.kernels_q4);
kernels = ctx.kernels_q4;
block_len = QK4_0;
} else if (tensor->type == GGML_TYPE_Q8_0) {
GGML_ASSERT(ctx.kernels_q8);
kernels = ctx.kernels_q8;
block_len = QK8_0;
} else {
return 0;
}
const size_t nr = kernels->gemm.get_nr();
const size_t kr = kernels->gemm.get_kr();
const size_t packed = kernels->rhs_info.packed_size_ex(n, k, nr, kr, block_len);
const size_t raw = ggml_nbytes(tensor);
return packed > raw ? packed : raw;
}
namespace ggml::cpu::kleidiai {
class extra_buffer_type : ggml::cpu::extra_buffer_type {
bool supports_op(ggml_backend_dev_t, const struct ggml_tensor * op) override {
if ((op->op == GGML_OP_MUL_MAT || op->op == GGML_OP_GET_ROWS) &&
op->src[0]->type == GGML_TYPE_Q4_0 &&
(op->src[0]->type == GGML_TYPE_Q4_0 || op->src[0]->type == GGML_TYPE_Q8_0) &&
op->src[0]->buffer &&
(ggml_n_dims(op->src[0]) == 2) &&
op->src[0]->buffer->buft == ggml_backend_cpu_kleidiai_buffer_type() && ctx.kernels) {
op->src[0]->buffer->buft == ggml_backend_cpu_kleidiai_buffer_type()) {
if (((op->src[0]->type == GGML_TYPE_Q4_0) ? ctx.kernels_q4 : ctx.kernels_q8) == nullptr) {
return false;
}
if (op->src[1]->buffer && !ggml_backend_buft_is_host(op->src[1]->buffer->buft)) {
return false;
}