llama.cpp/ggml-blas.cpp
2024-06-18 13:18:26 +02:00

632 lines
23 KiB
C++

#include "ggml-blas.h"
#include "ggml-backend-impl.h"
#include <atomic>
#include <cassert>
#include <future>
#include <vector>
#if defined(GGML_USE_ACCELERATE)
# include <Accelerate/Accelerate.h>
#elif defined(GGML_BLAS_USE_MKL)
# include <mkl.h>
#else
# include <cblas.h>
# ifdef BLIS_ENABLE_CBLAS
# include <blis.h>
# endif
#endif
struct ggml_backend_blas_context {
int n_threads = GGML_DEFAULT_N_THREADS;
std::unique_ptr<char[]> work_data;
size_t work_size = 0;
#ifndef GGML_USE_OPENMP
std::vector<std::future<void>> tasks;
#endif
std::atomic<int> current_chunk;
};
// helper function to determine if it is better to use BLAS or not
// for large matrices, BLAS is faster
static bool ggml_backend_blas_use_blas(const struct ggml_tensor * dst) {
const struct ggml_tensor * src0 = dst->src[0];
const struct ggml_tensor * src1 = dst->src[1];
const int64_t ne10 = src1->ne[0];
const int64_t ne0 = dst->ne[0];
const int64_t ne1 = dst->ne[1];
// TODO: find the optimal values for these
if (ggml_is_contiguous(src0) &&
ggml_is_contiguous(src1) &&
src1->type == GGML_TYPE_F32 &&
(ne0 >= 32 && ne1 >= 32 && ne10 >= 32)) {
/*printf("BLAS: %d %d %d %d %d\n", ne0, ne1, ne10, ne00, ne01);*/
return true;
}
return false;
}
static void ggml_compute_forward_mul_mat_one_chunk(
ggml_backend_blas_context * ctx,
struct ggml_tensor * dst,
const int64_t num_rows_per_vec_dot,
const int64_t ir0_start,
const int64_t ir0_end,
const int64_t ir1_start,
const int64_t ir1_end) {
const struct ggml_tensor * src0 = dst->src[0];
const struct ggml_tensor * src1 = dst->src[1];
GGML_TENSOR_BINARY_OP_LOCALS
const enum ggml_type type = src0->type;
const bool src1_cont = ggml_is_contiguous(src1);
const ggml_type_traits_t * type_traits = ggml_internal_get_type_traits_ptr(type);
ggml_vec_dot_t const vec_dot = type_traits->vec_dot;
enum ggml_type const vec_dot_type = type_traits->vec_dot_type;
// broadcast factors
const int64_t r2 = ne12 / ne02;
const int64_t r3 = ne13 / ne03;
//printf("ir0_start = %6lld, ir0_end = %6lld, ir1_start = %6lld, ir1_end = %6lld\n", ir0_start, ir0_end, ir1_start, ir1_end);
// threads with no work simply yield (not sure if it helps)
if (ir0_start >= ir0_end || ir1_start >= ir1_end) {
return;
}
const void * wdata = (src1->type == vec_dot_type) ? src1->data : ctx->work_data.get();
const size_t row_size = ggml_row_size(vec_dot_type, ne10);
assert(ne12 % ne02 == 0);
assert(ne13 % ne03 == 0);
// block-tiling attempt
const int64_t blck_0 = 16;
const int64_t blck_1 = 16;
const size_t src1_col_stride = src1_cont || src1->type != vec_dot_type ? row_size : nb11;
// attempt to reduce false-sharing (does not seem to make a difference)
// 16 * 2, accounting for mmla kernels
float tmp[32];
for (int64_t iir1 = ir1_start; iir1 < ir1_end; iir1 += blck_1) {
for (int64_t iir0 = ir0_start; iir0 < ir0_end; iir0 += blck_0) {
for (int64_t ir1 = iir1; ir1 < iir1 + blck_1 && ir1 < ir1_end; ir1 += num_rows_per_vec_dot) {
const int64_t i13 = (ir1 / (ne12 * ne1));
const int64_t i12 = (ir1 - i13 * ne12 * ne1) / ne1;
const int64_t i11 = (ir1 - i13 * ne12 * ne1 - i12 * ne1);
// broadcast src0 into src1
const int64_t i03 = i13 / r3;
const int64_t i02 = i12 / r2;
const int64_t i1 = i11;
const int64_t i2 = i12;
const int64_t i3 = i13;
const char * src0_row = (const char*)src0->data + (0 + i02 * nb02 + i03 * nb03);
// desc: when src1 is not a contiguous memory block we have to calculate the offset using the strides
// if it is, then we have either copied the data to params->wdata and made it contiguous or we are using
// the original src1 data pointer, so we should index using the indices directly
// TODO: this is a bit of a hack, we should probably have a better way to handle this
const char * src1_col = (const char*)wdata +
(src1_cont || src1->type != vec_dot_type
? (i11 + i12 * ne11 + i13 * ne12 * ne11) * row_size
: (i11 * nb11 + i12 * nb12 + i13 * nb13));
float * dst_col = (float*)((char*)dst->data + (i1 * nb1 + i2 * nb2 + i3 * nb3));
//for (int64_t ir0 = iir0; ir0 < iir0 + blck_0 && ir0 < ir0_end; ++ir0) {
// vec_dot(ne00, &dst_col[ir0], src0_row + ir0*nb01, src1_col);
//}
for (int64_t ir0 = iir0; ir0 < iir0 + blck_0 && ir0 < ir0_end; ir0 += num_rows_per_vec_dot) {
vec_dot(ne00, &tmp[ir0 - iir0], (num_rows_per_vec_dot > 1 ? 16 : 0), src0_row + ir0 * nb01, (num_rows_per_vec_dot > 1 ? nb01 : 0), src1_col, (num_rows_per_vec_dot > 1 ? src1_col_stride : 0), num_rows_per_vec_dot);
}
for (int cn = 0; cn < num_rows_per_vec_dot; ++cn) {
memcpy(&dst_col[iir0 + cn * nb1 / nb0], tmp + (cn * 16), (std::min(iir0 + blck_0, ir0_end) - iir0) * sizeof(float));
}
}
}
}
}
static void ggml_compute_forward_mul_mat(
ggml_backend_blas_context * ctx,
struct ggml_tensor * dst) {
const struct ggml_tensor * src0 = dst->src[0];
const struct ggml_tensor * src1 = dst->src[1];
GGML_TENSOR_BINARY_OP_LOCALS
const enum ggml_type type = src0->type;
const ggml_type_traits_t * type_traits = ggml_internal_get_type_traits_ptr(type);
const ggml_type_traits_t * type_traits_vec_dot = ggml_internal_get_type_traits_ptr(type_traits->vec_dot_type);
enum ggml_type const vec_dot_type = type_traits->vec_dot_type;
ggml_from_float_t const from_float_to_vec_dot = type_traits_vec_dot->from_float;
int64_t const vec_dot_num_rows = type_traits->nrows;
GGML_ASSERT(ne0 == ne01);
GGML_ASSERT(ne1 == ne11);
GGML_ASSERT(ne2 == ne12);
GGML_ASSERT(ne3 == ne13);
// we don't support permuted src0 or src1
GGML_ASSERT(nb00 == ggml_type_size(type));
GGML_ASSERT(nb10 == ggml_type_size(src1->type));
// dst cannot be transposed or permuted
GGML_ASSERT(nb0 == sizeof(float));
GGML_ASSERT(nb0 <= nb1);
GGML_ASSERT(nb1 <= nb2);
GGML_ASSERT(nb2 <= nb3);
// broadcast factors
const int64_t r2 = ne12 / ne02;
const int64_t r3 = ne13 / ne03;
GGML_UNUSED(r2);
GGML_UNUSED(r3);
// nb01 >= nb00 - src0 is not transposed
// compute by src0 rows
if (src1->type != vec_dot_type) {
const size_t row_size = ggml_row_size(vec_dot_type, ne10);
if (ctx->work_size < ne13*ne12*ne11*row_size) {
ctx->work_data.reset(new char[ne13*ne12*ne11*row_size]);
ctx->work_size = ne13*ne12*ne11*row_size;
}
char * wdata = ctx->work_data.get();
GGML_ASSERT(src1->type == GGML_TYPE_F32);
int block_size = ggml_blck_size(vec_dot_type);
int type_size = ggml_type_size(vec_dot_type);
for (int64_t i13 = 0; i13 < ne13; ++i13) {
for (int64_t i12 = 0; i12 < ne12; ++i12) {
for (int64_t i11 = 0; i11 < ne11; ++i11) {
//from_float_to_vec_dot((float *)((char *) src1->data + i13*nb13 + i12*nb12 + i11*nb11), (void *) wdata, ne10);
//#pragma omp parallel num_threads(ctx->n_threads)
{
int nth = omp_get_num_threads();
int ith = omp_get_thread_num();
int blocks_per_thread = (ne10 + block_size - 1) / block_size / nth;
int i10_start = ith * blocks_per_thread * block_size;
int i10_end = std::min(i10_start + blocks_per_thread * block_size, (int)ne10);
//printf("thread %d/%d: i10_start = %d, i10_end = %d\n", ith, nth, i10_start, i10_end);
from_float_to_vec_dot((float *)((char *) src1->data + i13*nb13 + i12*nb12 + i11*nb11 + i10_start*nb10),
(void *) ((char *) wdata + (type_size*i10_start/block_size)),
i10_end - i10_start);
}
wdata += row_size;
}
}
}
}
// This is the size of the first dimension of the result, so we can iterate that way. (see the ASSERT above, these are the same numbers)
const int64_t nr0 = ne0;
// This is the size of the rest of the dimensions of the result
const int64_t nr1 = ne1 * ne2 * ne3;
// dot kernels can handle 1 row and col at a time, but mmla kernels can process 2 rows and cols
int64_t num_rows_per_vec_dot = vec_dot_num_rows;
// TODO: currently the mmla kernels support only even numbered rows/cols.
// this check can be removed once they are extended to support odd numbered rows/cols too
if ((nr0 % 2 != 0) || (ne11 % 2 != 0)) {
num_rows_per_vec_dot = 1;
}
// Now select a reasonable chunk size.
int chunk_size = 16;
// We need to step up the size if it's small
if (nr0 == 1 || nr1 == 1) {
chunk_size = 64;
}
// distribute the work across the inner or outer loop based on which one is larger
// The number of chunks in the 0/1 dim.
// CEIL(nr0/chunk_size)
int64_t nchunk0 = (nr0 + chunk_size - 1) / chunk_size;
int64_t nchunk1 = (nr1 + chunk_size - 1) / chunk_size;
// If the chunking is poor for the number of threads on this setup, scrap the whole plan. Re-chunk it by thread.
// Also, chunking by thread was measured to have perform better on NUMA systems. See https://github.com/ggerganov/llama.cpp/pull/6915
// In theory, chunking should be just as useful on NUMA and non NUMA systems, but testing disagreed with that.
//const int ith = 0; // params->ith;
const int nth = ctx->n_threads;
// Every thread starts at ith, so the first unprocessed chunk is nth. This save a bit of coordination right at the start.
ctx->current_chunk.store(nth);
if (nchunk0 * nchunk1 < nth * 4 || ggml_is_numa()) {
// distribute the thread work across the inner or outer loop based on which one is larger
nchunk0 = nr0 > nr1 ? nth : 1; // parallelize by src0 rows
nchunk1 = nr0 > nr1 ? 1 : nth; // parallelize by src1 rows
}
// The number of elements in each chunk
const int64_t dr0 = (nr0 + nchunk0 - 1) / nchunk0;
const int64_t dr1 = (nr1 + nchunk1 - 1) / nchunk1;
//if (ith == 0)
// printf("MUL_MAT = [%d, %d, %d, %d] x [%d, %d, %d, %d] = %d x %d = %d. Fp Ops/Ch %d\n", ne00, ne01, ne02, ne03, ne10, ne11, ne12, ne13, nchunk0, nchunk1, nchunk0 * nchunk1, ne00 * nr0 * nr1 / nchunk0 / nchunk1);
// The first chunk comes from our thread_id, the rest will get auto-assigned.
if (nth > 1) {
#pragma omp parallel num_threads(nth)
{
int current_chunk = omp_get_thread_num();
while (current_chunk < nchunk0 * nchunk1) {
const int64_t ith0 = current_chunk % nchunk0;
const int64_t ith1 = current_chunk / nchunk0;
const int64_t ir0_start = dr0 * ith0;
const int64_t ir0_end = std::min(ir0_start + dr0, nr0);
const int64_t ir1_start = dr1 * ith1;
const int64_t ir1_end = std::min(ir1_start + dr1, nr1);
ggml_compute_forward_mul_mat_one_chunk(ctx, dst, num_rows_per_vec_dot, ir0_start, ir0_end, ir1_start, ir1_end);
if (nth >= nchunk0 * nchunk1) {
break;
}
current_chunk = ctx->current_chunk.fetch_add(1);
}
}
} else {
ggml_compute_forward_mul_mat_one_chunk(ctx, dst, num_rows_per_vec_dot, 0, nr0, 0, nr1);
}
#ifdef GGML_PERF
// These numbers are useful when trying to measure how well the threading scheduling works.
//int64_t workSize = (ne01 * ne11 * ne12 * ne13 * ne00) / nchunk0 / nchunk1;
//float time = (ggml_perf_time_us() - t0);
//printf("MUL_MAT = %f ms, [%d, %d, %d, %d] x [%d, %d, %d, %d] = %I64u, %f ops/usec in %d chunks.\n", time / 1000.0, ne00, ne01, ne02, ne03, ne10, ne11, ne12, ne13, workSize, (float)workSize/time, chunks_executed);
#endif
}
static void ggml_backend_blas_mul_mat(ggml_backend_blas_context * ctx, struct ggml_tensor * dst) {
const struct ggml_tensor * src0 = dst->src[0];
const struct ggml_tensor * src1 = dst->src[1];
GGML_TENSOR_BINARY_OP_LOCALS
const enum ggml_type type = src0->type;
GGML_ASSERT(ne0 == ne01);
GGML_ASSERT(ne1 == ne11);
GGML_ASSERT(ne2 == ne12);
GGML_ASSERT(ne3 == ne13);
// we don't support permuted src0 or src1
GGML_ASSERT(nb00 == ggml_type_size(type));
GGML_ASSERT(nb10 == ggml_type_size(src1->type));
// dst cannot be transposed or permuted
GGML_ASSERT(nb0 == sizeof(float));
GGML_ASSERT(nb0 <= nb1);
GGML_ASSERT(nb1 <= nb2);
GGML_ASSERT(nb2 <= nb3);
// broadcast factors
const int64_t r2 = ne12/ne02;
const int64_t r3 = ne13/ne03;
const int64_t ne_plane = ne01*ne00;
const size_t desired_wsize = type == GGML_TYPE_F32 ? 0 : ne03*ne02*ne_plane*sizeof(float);
if (ctx->work_size < desired_wsize) {
ctx->work_data.reset(new char[desired_wsize]);
ctx->work_size = desired_wsize;
}
void * wdata = ctx->work_data.get();
// convert src0 to float
if (type != GGML_TYPE_F32) {
ggml_type_traits_t type_traits = ggml_internal_get_type_traits(type);
ggml_to_float_t const to_float = type_traits.to_float;
for (int64_t i03 = 0; i03 < ne03; i03++) {
for (int64_t i02 = 0; i02 < ne02; i02++) {
const void * x = (char *) src0->data + i02*nb02 + i03*nb03;
float * const wplane = (float *) wdata + i02*ne_plane + i03*ne02*ne_plane;
const int min_cols_per_thread = 4096;
const int min_rows_per_thread = std::max((int)(min_cols_per_thread/ne00), 1);
const int n_threads = std::max(std::min(ctx->n_threads, (int)(ne01/min_rows_per_thread)), 1);
#ifdef GGML_USE_OPENMP
#pragma omp parallel for num_threads(n_threads)
for (int64_t i01 = 0; i01 < ne01; i01++) {
to_float((const char *) x + i01*nb01, wplane + i01*ne00, ne00);
}
#else
for (int i = 1; i < n_threads; i++) {
const int64_t start = i*ne01/n_threads;
const int64_t end = (i + 1)*ne01/n_threads;
if (start < end) {
ctx->tasks.push_back(std::async(std::launch::async, [=]() {
for (int64_t i01 = start; i01 < end; i01++) {
to_float((const char *) x + i01*nb01, wplane + i01*ne00, ne00);
}
}));
}
}
{
// reuse the current thread for the first task
const int64_t start = 0;
const int64_t end = ne01/n_threads;
for (int64_t i01 = start; i01 < end; i01++) {
to_float((const char *) x + i01*nb01, wplane + i01*ne00, ne00);
}
}
#endif
}
}
#ifndef GGML_USE_OPENMP
// wait for all tasks to finish
for (auto & task : ctx->tasks) {
task.get();
}
ctx->tasks.clear();
#endif
}
#if defined(OPENBLAS_VERSION)
openblas_set_num_threads(ctx->n_threads);
#endif
#if defined(BLIS_ENABLE_CBLAS)
bli_thread_set_num_threads(ctx->n_threads);
#endif
for (int64_t i13 = 0; i13 < ne13; i13++) {
for (int64_t i12 = 0; i12 < ne12; i12++) {
const int64_t i03 = i13/r3;
const int64_t i02 = i12/r2;
const float * x = (float *) ((char *) src0->data + i02*nb02 + i03*nb03);
const float * y = (float *) ((char *) src1->data + i12*nb12 + i13*nb13);
float * d = (float *) ((char *) dst->data + i12*nb2 + i13*nb3);
if (type != GGML_TYPE_F32) {
x = (float *) wdata + i02*ne_plane + i03*ne02*ne_plane;
}
cblas_sgemm(CblasRowMajor, CblasNoTrans, CblasTrans,
ne1, ne01, ne10,
1.0f, y, ne10,
x, ne00,
0.0f, d, ne01);
}
}
}
static void ggml_backend_blas_out_prod(ggml_backend_blas_context * ctx, struct ggml_tensor * dst) {
const struct ggml_tensor * src0 = dst->src[0];
const struct ggml_tensor * src1 = dst->src[1];
GGML_TENSOR_BINARY_OP_LOCALS
GGML_ASSERT(ne0 == ne00);
GGML_ASSERT(ne1 == ne10);
GGML_ASSERT(ne2 == ne02);
GGML_ASSERT(ne02 == ne12);
GGML_ASSERT(ne3 == ne13);
GGML_ASSERT(ne03 == ne13);
// we don't support permuted src0 or src1
GGML_ASSERT(nb00 == sizeof(float));
// dst cannot be transposed or permuted
GGML_ASSERT(nb0 == sizeof(float));
// GGML_ASSERT(nb0 <= nb1);
// GGML_ASSERT(nb1 <= nb2);
// GGML_ASSERT(nb2 <= nb3);
// Arguments to ggml_compute_forward_out_prod (expressed as major,minor)
// src0: (k,n)
// src1: (k,m)
// dst: (m,n)
//
// Arguments to sgemm (see https://github.com/Reference-LAPACK/lapack/blob/master/BLAS/SRC/sgemm.f)
// Also expressed as (major,minor)
// a: (m,k): so src1 transposed
// b: (k,n): so src0
// c: (m,n)
//
// However, if ggml_is_transposed(src1) is true, then
// src1->data already contains a transposed version, so sgemm mustn't
// transpose it further.
int n = src0->ne[0];
int k = src0->ne[1];
int m = src1->ne[0];
CBLAS_TRANSPOSE transposeA;
int lda;
if (!ggml_is_transposed(src1)) {
transposeA = CblasTrans;
lda = m;
} else {
transposeA = CblasNoTrans;
lda = k;
}
float * a = (float *) ((char *) src1->data);
float * b = (float *) ((char *) src0->data);
float * c = (float *) ((char *) dst->data);
cblas_sgemm(CblasRowMajor, transposeA, CblasNoTrans, m, n, k, 1.0, a, lda, b, n, 0.0, c, n);
GGML_UNUSED(ctx);
}
// backend interface
GGML_CALL static const char * ggml_backend_blas_name(ggml_backend_t backend) {
return "BLAS";
GGML_UNUSED(backend);
}
GGML_CALL static void ggml_backend_blas_free(ggml_backend_t backend) {
ggml_backend_blas_context * ctx = (ggml_backend_blas_context *)backend->context;
delete ctx;
delete backend;
}
GGML_CALL static ggml_backend_buffer_type_t ggml_backend_blas_get_default_buffer_type(ggml_backend_t backend) {
return ggml_backend_cpu_buffer_type();
GGML_UNUSED(backend);
}
GGML_CALL static enum ggml_status ggml_backend_blas_graph_compute(ggml_backend_t backend, struct ggml_cgraph * cgraph) {
ggml_backend_blas_context * ctx = (ggml_backend_blas_context *)backend->context;
for (int i = 0; i < cgraph->n_nodes; i++) {
struct ggml_tensor * node = cgraph->nodes[i];
switch (node->op) {
case GGML_OP_MUL_MAT:
//ggml_backend_blas_mul_mat(ctx, node);
ggml_compute_forward_mul_mat(ctx, node);
break;
case GGML_OP_OUT_PROD:
ggml_backend_blas_out_prod(ctx, node);
break;
case GGML_OP_NONE:
case GGML_OP_RESHAPE:
case GGML_OP_VIEW:
case GGML_OP_PERMUTE:
case GGML_OP_TRANSPOSE:
break;
default:
fprintf(stderr, "%s: unsupported op %s\n", __func__, ggml_op_desc(node));
GGML_ASSERT(false);
}
}
return GGML_STATUS_SUCCESS;
GGML_UNUSED(backend);
}
GGML_CALL static bool ggml_backend_blas_supports_op(ggml_backend_t backend, const struct ggml_tensor * op) {
return op->op == GGML_OP_MUL_MAT || op->op == GGML_OP_OUT_PROD;
/*
const struct ggml_tensor * src0 = op->src[0];
const struct ggml_tensor * src1 = op->src[1];
return (op->op == GGML_OP_MUL_MAT && ggml_backend_blas_use_blas(op)) ||
(op->op == GGML_OP_OUT_PROD && op->src[0]->type == GGML_TYPE_F32 &&
op->src[1]->type == GGML_TYPE_F32 &&
ggml_is_matrix(src0) &&
ggml_is_matrix(src1) &&
ggml_is_contiguous(src0) &&
(ggml_is_contiguous(src1) || ggml_is_transposed(src1)));
*/
GGML_UNUSED(backend);
}
GGML_CALL static bool ggml_backend_blas_supports_buft(ggml_backend_t backend, ggml_backend_buffer_type_t buft) {
return ggml_backend_buft_is_host(buft);
GGML_UNUSED(backend);
}
static struct ggml_backend_i blas_backend_i = {
/* .get_name = */ ggml_backend_blas_name,
/* .free = */ ggml_backend_blas_free,
/* .get_default_buffer_type = */ ggml_backend_blas_get_default_buffer_type,
/* .set_tensor_async = */ NULL,
/* .get_tensor_async = */ NULL,
/* .cpy_tensor_async = */ NULL,
/* .synchronize = */ NULL,
/* .graph_plan_create = */ NULL,
/* .graph_plan_free = */ NULL,
/* .graph_plan_update = */ NULL,
/* .graph_plan_compute = */ NULL,
/* .graph_compute = */ ggml_backend_blas_graph_compute,
/* .supports_op = */ ggml_backend_blas_supports_op,
/* .supports_buft = */ ggml_backend_blas_supports_buft,
/* .offload_op = */ NULL,
/* .event_new = */ NULL,
/* .event_free = */ NULL,
/* .event_record = */ NULL,
/* .event_wait = */ NULL,
/* .event_synchronize = */ NULL,
};
static ggml_guid_t ggml_backend_blas_guid(void) {
static ggml_guid guid = { 0x12, 0xa8, 0xae, 0xf4, 0xc0, 0x1e, 0x61, 0x97, 0x8f, 0xeb, 0x33, 0x04, 0xa1, 0x33, 0x51, 0x2d };
return &guid;
}
ggml_backend_t ggml_backend_blas_init(void) {
ggml_backend_blas_context * ctx = new ggml_backend_blas_context;
ggml_backend_t backend = new ggml_backend {
/* .guid = */ ggml_backend_blas_guid(),
/* .interface = */ blas_backend_i,
/* .context = */ ctx,
};
#if !defined(NDEBUG) && defined(OPENBLAS_VERSION) && defined(GGML_USE_OPENMP)
if (openblas_get_parallel() != OPENBLAS_OPENMP) {
fprintf(stderr, "%s: warning: ggml is using OpenMP, but OpenBLAS was compiled without OpenMP support\n", __func__);
}
#endif
#if !defined(NDEBUG) && defined(BLIS_ENABLE_CBLAS) && defined(GGML_USE_OPENMP) && !defined(BLIS_ENABLE_OPENMP)
fprintf(stderr, "%s: warning: ggml is using OpenMP, but BLIS was compiled without OpenMP support\n", __func__);
#endif
return backend;
}
GGML_CALL bool ggml_backend_is_blas(ggml_backend_t backend) {
return backend != NULL && ggml_guid_matches(backend->guid, ggml_backend_blas_guid());
}
void ggml_backend_blas_set_n_threads(ggml_backend_t backend_blas, int n_threads) {
GGML_ASSERT(ggml_backend_is_blas(backend_blas));
ggml_backend_blas_context * ctx = (ggml_backend_blas_context *)backend_blas->context;
ctx->n_threads = n_threads;
}