#include "cross_entropy_loss.hpp"
#include <cstdint>
#include <cmath>
template <bool has_shared>
static __dpct_inline__ void cross_entropy_loss_f32_kernel(
const float * __restrict__ logits,
const float * __restrict__ labels,
float * __restrict__ row_loss,
const int nclasses,
const int nrows,
float * __restrict__ smem,
const sycl::nd_item<3> & item) {
const int row = item.get_group(2);
const int tid = item.get_local_id(2);
logits += (int64_t) row * nclasses;
labels += (int64_t) row * nclasses;
float max_logit = -INFINITY;
for (int i = tid; i < nclasses; i += WARP_SIZE) {
const float v = logits[i];
max_logit = sycl::fmax(max_logit, v);
if (has_shared) {
smem[i] = v;
}
}
max_logit = warp_reduce_max<WARP_SIZE>(max_logit);
float sum_exp = 0.0f;
for (int i = tid; i < nclasses; i += WARP_SIZE) {
const float v = has_shared ? smem[i] : logits[i];
sum_exp += sycl::exp(v - max_logit);
}
sum_exp = warp_reduce_sum<WARP_SIZE>(sum_exp);
const float log_sum = sycl::log(sum_exp);
float loss = 0.0f;
for (int i = tid; i < nclasses; i += WARP_SIZE) {
const float v = has_shared ? smem[i] : logits[i];
loss += (v - max_logit - log_sum) * labels[i];
}
loss = -warp_reduce_sum<WARP_SIZE>(loss) / (float) nrows;
if (tid == 0) {
row_loss[row] = loss;
}
}
template <bool has_shared>
static __dpct_inline__ void cross_entropy_loss_back_f32_kernel(
const float * __restrict__ grad,
const float * __restrict__ logits,
const float * __restrict__ labels,
float * __restrict__ dst,
const int nclasses,
const int nrows,
float * __restrict__ smem,
const sycl::nd_item<3> & item) {
const int row = item.get_group(2);
const int tid = item.get_local_id(2);
logits += (int64_t) row * nclasses;
labels += (int64_t) row * nclasses;
dst += (int64_t) row * nclasses;
float max_logit = -INFINITY;
for (int i = tid; i < nclasses; i += WARP_SIZE) {
const float v = logits[i];
max_logit = sycl::fmax(max_logit, v);
if (has_shared) {
smem[i] = v;
}
}
max_logit = warp_reduce_max<WARP_SIZE>(max_logit);
float sum_exp = 0.0f;
for (int i = tid; i < nclasses; i += WARP_SIZE) {
const float v = sycl::exp((has_shared ? smem[i] : logits[i]) - max_logit);
sum_exp += v;
if (has_shared) {
smem[i] = v;
} else {
dst[i] = v;
}
}
sum_exp = warp_reduce_sum<WARP_SIZE>(sum_exp);
const float inv_sum = 1.0f / sum_exp;
const float d_by_nrows = grad[0] / (float) nrows;
for (int i = tid; i < nclasses; i += WARP_SIZE) {
const float sm_num = has_shared ? smem[i] : dst[i];
dst[i] = (sm_num * inv_sum - labels[i]) * d_by_nrows;
}
}
static void cross_entropy_reduce_rows(
ggml_backend_sycl_context & ctx,
const float * row_loss,
float * dst,
const int64_t nrows) {
if (nrows == 1) {
SYCL_CHECK(CHECK_TRY_ERROR(
ctx.stream()->memcpy(dst, row_loss, sizeof(float))));
return;
}
ggml_sycl_pool_alloc<float> tmp_alloc(ctx.pool(), nrows);
float * tmp = tmp_alloc.get();
SYCL_CHECK(CHECK_TRY_ERROR(
ctx.stream()->memcpy(tmp, row_loss, nrows * sizeof(float))));
int64_t cur = nrows;
while (cur > 1) {
const int64_t out = (cur + WARP_SIZE - 1) / WARP_SIZE;
const sycl::range<3> block(1, 1, WARP_SIZE);
const sycl::range<3> grid(1, 1, out);
ctx.stream()->parallel_for(
sycl::nd_range<3>(grid * block, block),
[=](sycl::nd_item<3> item) [[sycl::reqd_sub_group_size(WARP_SIZE)]] {
const int row = item.get_group(2);
const int tid = item.get_local_id(2);
const int64_t i = (int64_t) row * WARP_SIZE + tid;
float v = i < cur ? tmp[i] : 0.0f;
v = warp_reduce_sum<WARP_SIZE>(v);
if (tid == 0) {
tmp[row] = v;
}
});
cur = out;
}
SYCL_CHECK(CHECK_TRY_ERROR(
ctx.stream()->memcpy(dst, tmp, sizeof(float))));
}
void ggml_sycl_cross_entropy_loss(ggml_backend_sycl_context & ctx, ggml_tensor * dst) {
scope_op_debug_print scope_dbg_print(__func__, dst, 2);
const ggml_tensor * src0 = dst->src[0];
const ggml_tensor * src1 = dst->src[1];
GGML_ASSERT(src0->type == GGML_TYPE_F32);
GGML_ASSERT(src1->type == GGML_TYPE_F32);
GGML_ASSERT(dst->type == GGML_TYPE_F32);
GGML_ASSERT(ggml_is_contiguous(src0));
GGML_ASSERT(ggml_is_contiguous(src1));
GGML_ASSERT(ggml_is_contiguous(dst));
GGML_ASSERT(ggml_are_same_shape(src0, src1));
GGML_ASSERT(ggml_is_scalar(dst));
SYCL_CHECK(ggml_sycl_set_device(ctx.device));
const int64_t nclasses = src0->ne[0];
const int64_t nrows = ggml_nrows(src0);
const float * logits_d = (const float *) src0->data;
const float * labels_d = (const float *) src1->data;
float * dst_d = (float *) dst->data;
ggml_sycl_pool_alloc<float> row_loss_alloc(ctx.pool(), nrows);
float * row_loss = row_loss_alloc.get();
const sycl::range<3> block(1, 1, WARP_SIZE);
const sycl::range<3> grid(1, 1, nrows);
const size_t nbytes_shared = (size_t) nclasses * sizeof(float);
const size_t smpbo = ggml_sycl_info().devices[ctx.device].smpbo;
if (nbytes_shared <= smpbo) {
ctx.stream()->submit([&](sycl::handler & cgh) {
sycl::local_accessor<float, 1> smem(sycl::range<1>(nclasses), cgh);
cgh.parallel_for(
sycl::nd_range<3>(grid * block, block),
[=](sycl::nd_item<3> item) [[sycl::reqd_sub_group_size(WARP_SIZE)]] {
cross_entropy_loss_f32_kernel<true>(
logits_d, labels_d, row_loss,
(int) nclasses, (int) nrows,
get_pointer(smem), item);
});
});
} else {
ctx.stream()->parallel_for(
sycl::nd_range<3>(grid * block, block),
[=](sycl::nd_item<3> item) [[sycl::reqd_sub_group_size(WARP_SIZE)]] {
cross_entropy_loss_f32_kernel<false>(
logits_d, labels_d, row_loss,
(int) nclasses, (int) nrows,
nullptr, item);
});
}
cross_entropy_reduce_rows(ctx, row_loss, dst_d, nrows);
}
void ggml_sycl_cross_entropy_loss_back(ggml_backend_sycl_context & ctx, ggml_tensor * dst) {
scope_op_debug_print scope_dbg_print(__func__, dst, 3);
const ggml_tensor * grad = dst->src[0];
const ggml_tensor * src0f = dst->src[1];
const ggml_tensor * src1f = dst->src[2];
GGML_ASSERT(grad->type == GGML_TYPE_F32);
GGML_ASSERT(src0f->type == GGML_TYPE_F32);
GGML_ASSERT(src1f->type == GGML_TYPE_F32);
GGML_ASSERT(dst->type == GGML_TYPE_F32);
GGML_ASSERT(ggml_is_scalar(grad));
GGML_ASSERT(ggml_is_contiguous(grad));
GGML_ASSERT(ggml_is_contiguous(src0f));
GGML_ASSERT(ggml_is_contiguous(src1f));
GGML_ASSERT(ggml_is_contiguous(dst));
GGML_ASSERT(ggml_are_same_shape(src0f, src1f));
GGML_ASSERT(ggml_are_same_shape(src0f, dst));
SYCL_CHECK(ggml_sycl_set_device(ctx.device));
const int64_t nclasses = src0f->ne[0];
const int64_t nrows = ggml_nrows(src0f);
const float * grad_d = (const float *) grad->data;
const float * logits_d = (const float *) src0f->data;
const float * labels_d = (const float *) src1f->data;
float * dst_d = (float *) dst->data;
const sycl::range<3> block(1, 1, WARP_SIZE);
const sycl::range<3> grid(1, 1, nrows);
const size_t nbytes_shared = (size_t) nclasses * sizeof(float);
const size_t smpbo = ggml_sycl_info().devices[ctx.device].smpbo;
if (nbytes_shared <= smpbo) {
ctx.stream()->submit([&](sycl::handler & cgh) {
sycl::local_accessor<float, 1> smem(sycl::range<1>(nclasses), cgh);
cgh.parallel_for(
sycl::nd_range<3>(grid * block, block),
[=](sycl::nd_item<3> item) [[sycl::reqd_sub_group_size(WARP_SIZE)]] {
cross_entropy_loss_back_f32_kernel<true>(
grad_d, logits_d, labels_d, dst_d,
(int) nclasses, (int) nrows,
get_pointer(smem), item);
});
});
} else {
ctx.stream()->parallel_for(
sycl::nd_range<3>(grid * block, block),
[=](sycl::nd_item<3> item) [[sycl::reqd_sub_group_size(WARP_SIZE)]] {
cross_entropy_loss_back_f32_kernel<false>(
grad_d, logits_d, labels_d, dst_d,
(int) nclasses, (int) nrows,
nullptr, item);
});
}
}