mlx/mlx/backend/metal/binary.cpp
2024-11-24 09:17:10 -08:00

249 lines
7.6 KiB
C++

// Copyright © 2024 Apple Inc.
#include "mlx/backend/common/binary.h"
#include "mlx/backend/metal/device.h"
#include "mlx/backend/metal/kernels.h"
#include "mlx/backend/metal/utils.h"
#include "mlx/primitives.h"
#define BINARY_GPU(func) \
void func::eval_gpu(const std::vector<array>& inputs, array& out) { \
binary_op_gpu(inputs, out, get_primitive_string(this)); \
}
#define BINARY_GPU_MULTI(func) \
void func::eval_gpu( \
const std::vector<array>& inputs, std::vector<array>& outputs) { \
binary_op_gpu(inputs, outputs, get_primitive_string(this)); \
}
namespace mlx::core {
std::string get_kernel_name(
BinaryOpType bopt,
const std::string& op,
const array& a,
bool large,
int ndim,
int work_per_thread) {
std::string kname;
switch (bopt) {
case BinaryOpType::ScalarScalar:
kname = "ss";
break;
case BinaryOpType::ScalarVector:
kname = (large ? "sv2" : "sv");
break;
case BinaryOpType::VectorScalar:
kname = (large ? "vs2" : "vs");
break;
case BinaryOpType::VectorVector:
kname = (large ? "vv2" : "vv");
break;
case BinaryOpType::General:
kname = "g";
if (ndim <= 3) {
kname += std::to_string(ndim);
} else {
concatenate(kname, "n", std::to_string(work_per_thread));
}
if (large) {
kname += "large";
}
break;
}
concatenate(kname, "_", op, type_to_name(a));
return kname;
}
void binary_op_gpu_inplace(
const std::vector<array>& inputs,
std::vector<array>& outputs,
const std::string& op,
const Stream& s) {
auto& a = inputs[0];
auto& b = inputs[1];
auto bopt = get_binary_op_type(a, b);
auto& out = outputs[0];
if (out.size() == 0) {
return;
}
// Try to collapse contiguous dims
auto maybe_collapse = [bopt, &a, &b, &out]() {
if (bopt == BinaryOpType::General) {
auto [shape, strides] = collapse_contiguous_dims(a, b, out);
return std::make_tuple(shape, strides[0], strides[1], strides[2]);
} else {
std::vector<size_t> e;
return std::make_tuple(std::vector<int>{}, e, e, e);
}
};
auto [shape, strides_a, strides_b, strides_out] = maybe_collapse();
bool large = out.data_size() > UINT32_MAX;
auto ndim = shape.size();
int work_per_thread;
if (bopt == BinaryOpType::General) {
large |= (a.data_size() > UINT32_MAX || b.data_size() > UINT32_MAX);
work_per_thread = large ? 4 : 2;
} else {
work_per_thread = 1;
}
std::string kernel_name =
get_kernel_name(bopt, op, a, large, shape.size(), work_per_thread);
auto& d = metal::device(s.device);
auto kernel = outputs.size() == 2
? get_binary_two_kernel(d, kernel_name, a.dtype(), out.dtype(), op)
: get_binary_kernel(d, kernel_name, a.dtype(), out.dtype(), op);
auto& compute_encoder = d.get_command_encoder(s.index);
compute_encoder.set_compute_pipeline_state(kernel);
// - If a is donated it goes to the first output
// - If b is donated it goes to the first output if a was not donated
// otherwise it goes to the second output.
// - If there is only one output only one of a and b will be donated.
bool donate_a = a.data_shared_ptr() == nullptr;
bool donate_b = b.data_shared_ptr() == nullptr;
int arg_idx = 0;
compute_encoder.set_input_array(donate_a ? outputs[0] : a, arg_idx++);
compute_encoder.set_input_array(
donate_b ? (donate_a ? outputs[1] : outputs[0]) : b, arg_idx++);
compute_encoder.set_output_array(outputs[0], arg_idx++);
if (outputs.size() == 2) {
compute_encoder.set_output_array(outputs[1], arg_idx++);
}
auto thread_group_size = kernel->maxTotalThreadsPerThreadgroup();
if (bopt == BinaryOpType::General) {
// Launch up to 3D grid of threads
size_t dim0 = ndim > 0 ? shape[ndim - 1] : 1;
size_t dim1 = ndim > 1 ? shape[ndim - 2] : 1;
size_t rest = out.size() / (dim0 * dim1);
if (ndim > 3) {
compute_encoder.set_vector_bytes(shape, arg_idx++);
compute_encoder.set_vector_bytes(strides_a, arg_idx++);
compute_encoder.set_vector_bytes(strides_b, arg_idx++);
compute_encoder.set_bytes<int>(ndim, arg_idx++);
dim0 = (dim0 + work_per_thread - 1) / work_per_thread;
} else {
// The shape is implicit in the grid for <= 3D
compute_encoder.set_vector_bytes(strides_a, arg_idx++);
compute_encoder.set_vector_bytes(strides_b, arg_idx++);
}
if (thread_group_size != 1024) {
throw std::runtime_error("[Metal::binary] Must use 1024 sized block");
}
auto group_dims = get_block_dims(dim0, dim1, rest);
MTL::Size grid_dims = MTL::Size(dim0, dim1, rest);
compute_encoder.dispatch_threads(grid_dims, group_dims);
} else {
// Launch a 1D or 2D grid of threads
size_t nthreads = out.data_size();
if (thread_group_size > nthreads) {
thread_group_size = nthreads;
}
MTL::Size group_dims = MTL::Size(thread_group_size, 1, 1);
MTL::Size grid_dims = large ? get_2d_grid_dims(out.shape(), out.strides())
: MTL::Size(nthreads, 1, 1);
compute_encoder.dispatch_threads(grid_dims, group_dims);
}
}
void binary_op_gpu(
const std::vector<array>& inputs,
std::vector<array>& outputs,
const std::string& op,
const Stream& s) {
assert(inputs.size() == 2);
auto& a = inputs[0];
auto& b = inputs[1];
auto bopt = get_binary_op_type(a, b);
set_binary_op_output_data(a, b, outputs[0], bopt, true);
set_binary_op_output_data(a, b, outputs[1], bopt, true);
binary_op_gpu_inplace(inputs, outputs, op, s);
}
void binary_op_gpu(
const std::vector<array>& inputs,
std::vector<array>& outputs,
const std::string& op) {
auto& s = outputs[0].primitive().stream();
binary_op_gpu(inputs, outputs, op, s);
}
void binary_op_gpu_inplace(
const std::vector<array>& inputs,
array& out,
const std::string& op,
const Stream& s) {
std::vector<array> outputs = {out};
binary_op_gpu_inplace(inputs, outputs, op, s);
}
void binary_op_gpu(
const std::vector<array>& inputs,
array& out,
const std::string& op,
const Stream& s) {
assert(inputs.size() == 2);
auto& a = inputs[0];
auto& b = inputs[1];
auto bopt = get_binary_op_type(a, b);
set_binary_op_output_data(a, b, out, bopt, true);
binary_op_gpu_inplace(inputs, out, op, s);
}
void binary_op_gpu(
const std::vector<array>& inputs,
array& out,
const std::string& op) {
auto& s = out.primitive().stream();
binary_op_gpu(inputs, out, op, s);
}
BINARY_GPU(Add)
BINARY_GPU(ArcTan2)
BINARY_GPU(Divide)
BINARY_GPU_MULTI(DivMod)
BINARY_GPU(Remainder)
BINARY_GPU(Equal)
BINARY_GPU(Greater)
BINARY_GPU(GreaterEqual)
BINARY_GPU(Less)
BINARY_GPU(LessEqual)
BINARY_GPU(LogicalAnd)
BINARY_GPU(LogicalOr)
BINARY_GPU(LogAddExp)
BINARY_GPU(Maximum)
BINARY_GPU(Minimum)
BINARY_GPU(Multiply)
BINARY_GPU(NotEqual)
BINARY_GPU(Power)
BINARY_GPU(Subtract)
void BitwiseBinary::eval_gpu(const std::vector<array>& inputs, array& out) {
switch (op_) {
case BitwiseBinary::And:
binary_op_gpu(inputs, out, get_primitive_string(this));
break;
case BitwiseBinary::Or:
binary_op_gpu(inputs, out, get_primitive_string(this));
break;
case BitwiseBinary::Xor:
binary_op_gpu(inputs, out, get_primitive_string(this));
break;
case BitwiseBinary::LeftShift:
binary_op_gpu(inputs, out, get_primitive_string(this));
break;
case BitwiseBinary::RightShift:
binary_op_gpu(inputs, out, get_primitive_string(this));
break;
}
}
} // namespace mlx::core