vllm/csrc/cpu/quant.cpp

298 lines
11 KiB
C++

#include "cpu_types.hpp"
#include "dnnl_helper.hpp"
namespace {
template <typename scalar_t>
struct KernelVecType {
using load_vec_type = void;
using cvt_vec_type = void;
};
template <>
struct KernelVecType<float> {
using load_vec_type = vec_op::FP32Vec16;
using cvt_vec_type = vec_op::FP32Vec16;
};
template <>
struct KernelVecType<c10::BFloat16> {
using load_vec_type = vec_op::BF16Vec16;
using cvt_vec_type = vec_op::FP32Vec16;
};
#ifdef __AVX512F__
template <typename scalar_t>
void static_scaled_int8_quant_impl(const scalar_t* input, int8_t* output,
const float* scale, const int num_tokens,
const int hidden_size) {
using load_vec_t = typename KernelVecType<scalar_t>::load_vec_type;
using cvt_vec_t = typename KernelVecType<scalar_t>::cvt_vec_type;
constexpr int vec_elem_num = load_vec_t::VEC_ELEM_NUM;
constexpr float i8_min =
static_cast<float>(std::numeric_limits<int8_t>::min());
constexpr float i8_max =
static_cast<float>(std::numeric_limits<int8_t>::max());
const cvt_vec_t inv_scale(1.0 / *scale);
const cvt_vec_t i8_min_vec(i8_min);
const cvt_vec_t i8_max_vec(i8_max);
#pragma omp parallel for
for (int i = 0; i < num_tokens; ++i) {
int j = 0;
for (; j < hidden_size - vec_elem_num; j += vec_elem_num) {
load_vec_t elems(input + i * hidden_size + j);
cvt_vec_t elems_fp32(elems);
elems_fp32 = (elems_fp32 * inv_scale).clamp(i8_min_vec, i8_max_vec);
vec_op::INT8Vec16 elems_int8(elems_fp32);
elems_int8.save(output + i * hidden_size + j);
}
load_vec_t elems(input + i * hidden_size + j);
cvt_vec_t elems_fp32(elems);
elems_fp32 = (elems_fp32 * inv_scale).clamp(i8_min_vec, i8_max_vec);
vec_op::INT8Vec16 elems_int8(elems_fp32);
if (j + vec_elem_num == hidden_size) {
elems_int8.save(output + i * hidden_size + j);
} else {
elems_int8.save(output + i * hidden_size + j, hidden_size - j);
}
}
}
template <typename scalar_t>
void dynamic_scaled_int8_quant_impl(const scalar_t* input, int8_t* output,
float* scale, const int num_tokens,
const int hidden_size) {
using load_vec_t = typename KernelVecType<scalar_t>::load_vec_type;
using cvt_vec_t = typename KernelVecType<scalar_t>::cvt_vec_type;
constexpr int vec_elem_num = load_vec_t::VEC_ELEM_NUM;
#pragma omp parallel for
for (int i = 0; i < num_tokens; ++i) {
cvt_vec_t max_abs(0.0);
{
int j = 0;
for (; j < hidden_size - vec_elem_num; j += vec_elem_num) {
load_vec_t elems(input + i * hidden_size + j);
cvt_vec_t elems_fp32(elems);
max_abs = max_abs.max(elems_fp32.abs());
}
load_vec_t elems(input + i * hidden_size + j);
cvt_vec_t elems_fp32(elems);
if (j + vec_elem_num == hidden_size) {
max_abs = max_abs.max(elems_fp32.abs());
} else {
max_abs = max_abs.max(elems_fp32.abs(), hidden_size - j);
}
}
float scale_val = max_abs.reduce_max() / 127.0f;
scale[i] = scale_val;
const cvt_vec_t inv_scale(1.0 / scale_val);
{
int j = 0;
for (; j < hidden_size - vec_elem_num; j += vec_elem_num) {
load_vec_t elems(input + i * hidden_size + j);
cvt_vec_t elems_fp32(elems);
elems_fp32 = (elems_fp32 * inv_scale);
vec_op::INT8Vec16 elems_int8(elems_fp32);
elems_int8.save(output + i * hidden_size + j);
}
load_vec_t elems(input + i * hidden_size + j);
cvt_vec_t elems_fp32(elems);
elems_fp32 = (elems_fp32 * inv_scale);
vec_op::INT8Vec16 elems_int8(elems_fp32);
if (j + vec_elem_num == hidden_size) {
elems_int8.save(output + i * hidden_size + j);
} else {
elems_int8.save(output + i * hidden_size + j, hidden_size - j);
}
}
}
}
template <bool Bias, typename scalar_t>
void dynamic_output_scale_impl(const float* input, scalar_t* output,
const float* scale, const scalar_t* bias,
const int num_tokens, const int hidden_size) {
CPU_KERNEL_GUARD_IN(dynamic_output_scale_impl)
using load_vec_t = typename KernelVecType<scalar_t>::load_vec_type;
using cvt_vec_t = typename KernelVecType<scalar_t>::cvt_vec_type;
constexpr int vec_elem_num = load_vec_t::VEC_ELEM_NUM;
#pragma omp parallel for
for (int i = 0; i < num_tokens; ++i) {
int j = 0;
cvt_vec_t token_scale_vec(scale[i]);
for (; j < hidden_size - vec_elem_num; j += vec_elem_num) {
cvt_vec_t elems_fp32(input + i * hidden_size + j);
elems_fp32 = elems_fp32 * token_scale_vec;
if constexpr (Bias) {
load_vec_t bias_vec(bias + j);
cvt_vec_t bias_vec_fp32(bias_vec);
elems_fp32 = elems_fp32 + bias_vec_fp32;
}
load_vec_t elems_out(elems_fp32);
elems_out.save(output + i * hidden_size + j);
}
cvt_vec_t elems_fp32(input + i * hidden_size + j);
elems_fp32 = elems_fp32 * token_scale_vec;
if constexpr (Bias) {
load_vec_t bias_vec(bias + j);
cvt_vec_t bias_vec_fp32(bias_vec);
elems_fp32 = elems_fp32 + bias_vec_fp32;
}
load_vec_t elems_out(elems_fp32);
if (j + vec_elem_num == hidden_size) {
elems_out.save(output + i * hidden_size + j);
} else {
elems_out.save(output + i * hidden_size + j, hidden_size - j);
}
}
}
#else
template <typename scalar_t>
void static_scaled_int8_quant_impl(const scalar_t* input, int8_t* output,
const float* scale, const int num_tokens,
const int hidden_size) {
TORCH_CHECK(false, "static_scaled_int8_quant_impl requires AVX512 support.")
}
template <typename scalar_t>
void dynamic_scaled_int8_quant_impl(const scalar_t* input, int8_t* output,
float* scale, const int num_tokens,
const int hidden_size) {
TORCH_CHECK(false, "dynamic_scaled_int8_quant_impl requires AVX512 support.")
}
template <typename scalar_t>
void dynamic_output_scale_impl() {
TORCH_CHECK(false, "dynamic_output_scale_impl requires AVX512 support.")
}
#endif
} // namespace
void int8_scaled_mm(torch::Tensor& c, // [M, OC], row-major
const torch::Tensor& a, // [M, IC], row-major
const torch::Tensor& b, // [IC, OC], column-major
const torch::Tensor& a_scales, // [1] or [M]
const torch::Tensor& b_scales, // [1] or [OC]
const c10::optional<torch::Tensor>& bias // [OC]
) {
CPU_KERNEL_GUARD_IN(cutlass_scaled_mm)
// Checks for conformality
TORCH_CHECK(a.dtype() == torch::kInt8 && b.dtype() == torch::kInt8,
"int8_scaled_mm only supports INT8 inputs.")
TORCH_CHECK(a.dim() == 2 && b.dim() == 2 && c.dim() == 2);
TORCH_CHECK(c.size(0) == a.size(0) && a.size(1) == b.size(0) &&
b.size(1) == c.size(1));
TORCH_CHECK(a_scales.numel() == 1 || a_scales.numel() == a.size(0));
TORCH_CHECK(b_scales.numel() == 1 || b_scales.numel() == b.size(1));
// Check for strides and alignment
TORCH_CHECK(a.stride(1) == 1 && c.stride(1) == 1); // Row-major
TORCH_CHECK(b.stride(0) == 1); // Column-major
TORCH_CHECK(c.stride(0) % 16 == 0 &&
b.stride(1) % 16 == 0); // 16 Byte Alignment
TORCH_CHECK(a_scales.is_contiguous() && b_scales.is_contiguous());
if (bias) {
TORCH_CHECK(bias->numel() == b.size(1) && bias->is_contiguous() &&
bias->dim() == 1);
}
VLLM_DISPATCH_FLOATING_TYPES(c.scalar_type(), "cutlass_scaled_mm", [&] {
if (a_scales.numel() != 1) {
// per-token
// Note: oneDNN doesn't support per-token activation quantization
torch::Tensor tmp_fp32_out =
torch::empty_like(c, ::at::ScalarType::Float);
DNNLPrimitiveHelper<true>::gemm_s8s8_jit(
a.data_ptr<int8_t>(), b.data_ptr<int8_t>(),
tmp_fp32_out.data_ptr<float>(), (void*)(0), a.size(0), b.size(1),
a.size(1), (float*)(0), b_scales.data_ptr<float>(), 0,
b_scales.numel());
if (bias.has_value()) {
dynamic_output_scale_impl<true>(
tmp_fp32_out.data_ptr<float>(), c.data_ptr<scalar_t>(),
a_scales.data_ptr<float>(), bias->data_ptr<scalar_t>(), c.size(0),
c.size(1));
} else {
dynamic_output_scale_impl<false>(
tmp_fp32_out.data_ptr<float>(), c.data_ptr<scalar_t>(),
a_scales.data_ptr<float>(), (scalar_t*)(0), c.size(0), c.size(1));
}
} else {
// per-tensor
if (bias.has_value()) {
DNNLPrimitiveHelper<false>::gemm_s8s8_jit(
a.data_ptr<int8_t>(), b.data_ptr<int8_t>(), c.data_ptr<scalar_t>(),
bias->data_ptr<scalar_t>(), a.size(0), b.size(1), a.size(1),
a_scales.data_ptr<float>(), b_scales.data_ptr<float>(),
a_scales.numel(), b_scales.numel());
} else {
DNNLPrimitiveHelper<false>::gemm_s8s8_jit(
a.data_ptr<int8_t>(), b.data_ptr<int8_t>(), c.data_ptr<scalar_t>(),
(void*)(0), a.size(0), b.size(1), a.size(1),
a_scales.data_ptr<float>(), b_scales.data_ptr<float>(),
a_scales.numel(), b_scales.numel());
}
}
});
}
// static-per-tensor quantization.
void static_scaled_int8_quant(torch::Tensor& out, // [..., hidden_size]
const torch::Tensor& input, // [..., hidden_size]
const torch::Tensor& scale,
c10::optional<torch::Tensor> const& azp) {
CPU_KERNEL_GUARD_IN(static_scaled_int8_quant)
TORCH_CHECK(input.is_contiguous());
TORCH_CHECK(out.is_contiguous());
TORCH_CHECK(scale.numel() == 1);
TORCH_CHECK(!azp.has_value(), "Zero point is not supported on CPU.");
const int hidden_size = input.size(-1);
const int num_tokens = input.numel() / hidden_size;
VLLM_DISPATCH_FLOATING_TYPES(
input.scalar_type(), "static_scaled_int8_quant_impl", [&] {
static_scaled_int8_quant_impl(
input.data_ptr<scalar_t>(), out.data_ptr<int8_t>(),
scale.data_ptr<float>(), num_tokens, hidden_size);
});
}
// dynamic-per-token quantization.
void dynamic_scaled_int8_quant(
torch::Tensor& out, // [..., hidden_size]
const torch::Tensor& input, // [..., hidden_size]
torch::Tensor& scale, // [..., 1]
c10::optional<torch::Tensor> const& azp) {
CPU_KERNEL_GUARD_IN(dynamic_scaled_int8_quant)
TORCH_CHECK(input.is_contiguous());
TORCH_CHECK(out.is_contiguous());
TORCH_CHECK(!azp.has_value(), "Zero point is not supported on CPU.");
int const hidden_size = input.size(-1);
int const num_tokens = input.numel() / hidden_size;
VLLM_DISPATCH_FLOATING_TYPES(
input.scalar_type(), "dynamic_scaled_int8_quant_impl", [&] {
dynamic_scaled_int8_quant_impl(
input.data_ptr<scalar_t>(), out.data_ptr<int8_t>(),
scale.data_ptr<float>(), num_tokens, hidden_size);
});
}