Support for quantized matmul with w and w^T (#349)

* Add the metal qvm implementation
* Add qmm_n
* Add gradient wrt to input for quantized_matmul
This commit is contained in:
Angelos Katharopoulos
2024-01-03 14:22:36 -08:00
committed by GitHub
parent d7ac050f4b
commit e7f5059fe4
12 changed files with 718 additions and 193 deletions

View File

@@ -1,7 +1,6 @@
// Copyright © 2023 Apple Inc.
#include <cassert>
#include <iostream>
#include "mlx/backend/metal/copy.h"
#include "mlx/backend/metal/device.h"
@@ -23,97 +22,147 @@ void QuantizedMatmul::eval_gpu(const std::vector<array>& inputs, array& out) {
auto& biases_pre = inputs[3];
std::vector<array> copies;
auto check_transpose = [&copies, &s](const array& arr) {
auto stx = arr.strides()[arr.ndim() - 2];
auto sty = arr.strides()[arr.ndim() - 1];
if (stx == arr.shape(-1) && sty == 1) {
return std::make_tuple(false, stx, arr);
} else if (stx == 1 && sty == arr.shape(-2)) {
return std::make_tuple(true, sty, arr);
auto ensure_row_contiguous = [&copies, &s](const array& arr) {
if (arr.flags().row_contiguous) {
return arr;
} else {
array arr_copy(arr.shape(), arr.dtype(), nullptr, {});
copy_gpu(arr, arr_copy, CopyType::General, s);
copies.push_back(arr_copy);
size_t stx = arr.shape(-1);
return std::make_tuple(false, stx, arr_copy);
return arr_copy;
}
};
auto [x_transposed, x_cols, x] = check_transpose(x_pre);
auto [w_transposed, w_cols, w] = check_transpose(w_pre);
auto [scales_transposed, scales_cols, scales] = check_transpose(scales_pre);
auto [biases_transposed, biases_cols, biases] = check_transpose(biases_pre);
if (!w_transposed) {
throw std::runtime_error("The quantized weight should be transposed.");
}
if (x_transposed || scales_transposed || biases_transposed) {
throw std::runtime_error("x, scales and biases should be row contiguous.");
}
auto x = ensure_row_contiguous(x_pre);
auto w = ensure_row_contiguous(w_pre);
auto scales = ensure_row_contiguous(scales_pre);
auto biases = ensure_row_contiguous(biases_pre);
int D = x.shape(-1);
int B = x.size() / D;
int O = out.shape(-1);
if (transpose_) {
// Route to the qmv kernel
if (B < 6) {
std::ostringstream kname;
kname << "qmv_" << type_to_name(out) << "_gs_" << group_size_ << "_b_"
<< bits_;
// Route to the qmv kernel
if (B == 1) {
std::ostringstream kname;
kname << "qmv_" << (w_transposed ? "n_" : "t_") << type_to_name(out)
<< "_gs_" << group_size_ << "_b_" << bits_;
// Encode and dispatch kernel
auto compute_encoder = d.get_command_encoder(s.index);
auto kernel = d.get_kernel(kname.str());
compute_encoder->setComputePipelineState(kernel);
// Encode and dispatch kernel
auto compute_encoder = d.get_command_encoder(s.index);
auto kernel = d.get_kernel(kname.str());
compute_encoder->setComputePipelineState(kernel);
int bo = 32;
int bd = 32;
MTL::Size group_dims = MTL::Size(bd, bo, 1);
MTL::Size grid_dims = MTL::Size(1, O / bo, B);
int O = w.size() / w_cols;
set_array_buffer(compute_encoder, w, 0);
set_array_buffer(compute_encoder, scales, 1);
set_array_buffer(compute_encoder, biases, 2);
set_array_buffer(compute_encoder, x, 3);
set_array_buffer(compute_encoder, out, 4);
compute_encoder->setBytes(&D, sizeof(int), 5);
compute_encoder->setBytes(&O, sizeof(int), 6);
int bo = 32;
int bd = 32;
MTL::Size group_dims = MTL::Size(bd, bo, 1);
MTL::Size grid_dims = MTL::Size(1, O / bo, B);
compute_encoder->dispatchThreadgroups(grid_dims, group_dims);
}
set_array_buffer(compute_encoder, w, 0);
set_array_buffer(compute_encoder, scales, 1);
set_array_buffer(compute_encoder, biases, 2);
set_array_buffer(compute_encoder, x, 3);
set_array_buffer(compute_encoder, out, 4);
compute_encoder->setBytes(&D, sizeof(int), 5);
compute_encoder->setBytes(&O, sizeof(int), 6);
// Route to the qmm_t kernel
else {
std::ostringstream kname;
kname << "qmm_t_" << type_to_name(out) << "_gs_" << group_size_ << "_b_"
<< bits_;
compute_encoder->dispatchThreadgroups(grid_dims, group_dims);
}
// Encode and dispatch kernel
auto compute_encoder = d.get_command_encoder(s.index);
auto kernel = d.get_kernel(kname.str());
compute_encoder->setComputePipelineState(kernel);
// Route to the qmm kernel
else {
std::ostringstream kname;
kname << "qmm_" << (w_transposed ? "t_" : "n_") << type_to_name(out)
<< "_gs_" << group_size_ << "_b_" << bits_;
int wn = 2;
int wm = 2;
int bm = 32;
int bn = 32;
int bk = 64;
MTL::Size group_dims = MTL::Size(32, wn, wm);
MTL::Size grid_dims = MTL::Size(O / bn, (B + bm - 1) / bm, 1);
// Encode and dispatch kernel
auto compute_encoder = d.get_command_encoder(s.index);
auto kernel = d.get_kernel(kname.str());
compute_encoder->setComputePipelineState(kernel);
set_array_buffer(compute_encoder, x, 0);
set_array_buffer(compute_encoder, w, 1);
set_array_buffer(compute_encoder, scales, 2);
set_array_buffer(compute_encoder, biases, 3);
set_array_buffer(compute_encoder, out, 4);
compute_encoder->setBytes(&B, sizeof(int), 5);
compute_encoder->setBytes(&O, sizeof(int), 6);
compute_encoder->setBytes(&D, sizeof(int), 7);
int O = w.size() / w_cols;
compute_encoder->dispatchThreadgroups(grid_dims, group_dims);
}
} else {
// Route to the qvm kernel
if (B < 4) {
std::ostringstream kname;
kname << "qvm_" << type_to_name(out) << "_gs_" << group_size_ << "_b_"
<< bits_;
int wn = 2;
int wm = 2;
int bm = 32;
int bn = 32;
int bk = 64;
MTL::Size group_dims = MTL::Size(32, wn, wm);
MTL::Size grid_dims = MTL::Size(O / bn, (B + bm - 1) / bm, 1);
// Encode and dispatch kernel
auto compute_encoder = d.get_command_encoder(s.index);
auto kernel = d.get_kernel(kname.str());
compute_encoder->setComputePipelineState(kernel);
set_array_buffer(compute_encoder, x, 0);
set_array_buffer(compute_encoder, w, 1);
set_array_buffer(compute_encoder, scales, 2);
set_array_buffer(compute_encoder, biases, 3);
set_array_buffer(compute_encoder, out, 4);
compute_encoder->setBytes(&B, sizeof(int), 5);
compute_encoder->setBytes(&O, sizeof(int), 6);
compute_encoder->setBytes(&D, sizeof(int), 7);
int bo = 32;
int bd = 32;
MTL::Size group_dims = MTL::Size(bd, bo, 1);
MTL::Size grid_dims = MTL::Size(1, (w.shape(1) + bo - 1) / bo, B);
compute_encoder->dispatchThreadgroups(grid_dims, group_dims);
set_array_buffer(compute_encoder, x, 0);
set_array_buffer(compute_encoder, w, 1);
set_array_buffer(compute_encoder, scales, 2);
set_array_buffer(compute_encoder, biases, 3);
set_array_buffer(compute_encoder, out, 4);
compute_encoder->setBytes(&D, sizeof(int), 5);
compute_encoder->setBytes(&O, sizeof(int), 6);
compute_encoder->dispatchThreadgroups(grid_dims, group_dims);
}
// Route to the qmm_n kernel
else {
std::ostringstream kname;
kname << "qmm_n_" << type_to_name(out) << "_gs_" << group_size_ << "_b_"
<< bits_;
// Encode and dispatch kernel
auto compute_encoder = d.get_command_encoder(s.index);
auto kernel = d.get_kernel(kname.str());
compute_encoder->setComputePipelineState(kernel);
int wn = 2;
int wm = 2;
int bm = 32;
int bn = 64;
int bk = 32;
MTL::Size group_dims = MTL::Size(32, wn, wm);
MTL::Size grid_dims = MTL::Size(O / bn, (B + bm - 1) / bm, 1);
if ((O % bn) != 0) {
std::ostringstream msg;
msg << "[quantized_matmul] The output size should be divisible by "
<< bn << " but received " << O << ".";
throw std::runtime_error(msg.str());
}
set_array_buffer(compute_encoder, x, 0);
set_array_buffer(compute_encoder, w, 1);
set_array_buffer(compute_encoder, scales, 2);
set_array_buffer(compute_encoder, biases, 3);
set_array_buffer(compute_encoder, out, 4);
compute_encoder->setBytes(&B, sizeof(int), 5);
compute_encoder->setBytes(&O, sizeof(int), 6);
compute_encoder->setBytes(&D, sizeof(int), 7);
compute_encoder->dispatchThreadgroups(grid_dims, group_dims);
}
}
d.get_command_buffer(s.index)->addCompletedHandler(