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[aot] [CUDA-AOT PR #0] Refactored compile_module_to_executable() to C…
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…UDAModuleToFunctionConverter
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jim19930609 committed May 31, 2022
1 parent 69a53fe commit e55caa0
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252 changes: 137 additions & 115 deletions taichi/backends/cuda/codegen_cuda.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,7 @@
#include "taichi/backends/cuda/cuda_context.h"
#include "taichi/codegen/codegen_llvm.h"
#include "taichi/llvm/llvm_program.h"
#include "taichi/util/action_recorder.h"

TLANG_NAMESPACE_BEGIN

Expand All @@ -37,123 +38,12 @@ class CodeGenLLVMCUDA : public CodeGenLLVM {

FunctionType gen() override {
auto compiled_res = run_compilation();
return compile_module_to_executable(this->kernel, std::move(compiled_res));
}

static FunctionType compile_module_to_executable(
Kernel *kernel,
CompiledData &&compiled_data) {
#ifdef TI_WITH_CUDA
auto *tlctx =
kernel->program->get_llvm_program_impl()->get_llvm_context(Arch::cuda);
for (auto &task : compiled_data.offloaded_tasks) {
llvm::Function *func = compiled_data.llvm_module->getFunction(task.name);
TI_ASSERT(func);
tlctx->mark_function_as_cuda_kernel(func, task.block_dim);
}

auto jit = tlctx->jit.get();
auto cuda_module = jit->add_module(std::move(compiled_data.llvm_module),
kernel->program->config.gpu_max_reg);

return [cuda_module, kernel,
offloaded_tasks =
compiled_data.offloaded_tasks](RuntimeContext &context) {
CUDAContext::get_instance().make_current();
auto args = kernel->args;
std::vector<void *> arg_buffers(args.size(), nullptr);
std::vector<void *> device_buffers(args.size(), nullptr);

// We could also use kernel->make_launch_context() to create
// |ctx_builder|, but that implies the usage of Program's context. For the
// sake of decoupling, let's not do that and explicitly set the context we
// want to modify.
Kernel::LaunchContextBuilder ctx_builder(kernel, &context);
bool transferred = false;
for (int i = 0; i < (int)args.size(); i++) {
if (args[i].is_array) {
const auto arr_sz = context.array_runtime_sizes[i];
if (arr_sz == 0) {
continue;
}
arg_buffers[i] = context.get_arg<void *>(i);
if (!context.is_device_allocations[i]) {
// Note: both numpy and PyTorch support arrays/tensors with zeros
// in shapes, e.g., shape=(0) or shape=(100, 0, 200). This makes
// `arr_sz` zero.
unsigned int attr_val = 0;
uint32_t ret_code =
CUDADriver::get_instance().mem_get_attribute.call(
&attr_val, CU_POINTER_ATTRIBUTE_MEMORY_TYPE,
(void *)arg_buffers[i]);
if (ret_code != CUDA_SUCCESS || attr_val != CU_MEMORYTYPE_DEVICE) {
// Copy to device buffer if arg is on host
// - ret_code != CUDA_SUCCESS:
// arg_buffers[i] is not on device
// - attr_val != CU_MEMORYTYPE_DEVICE:
// Cuda driver is aware of arg_buffers[i] but it might be on
// host.
// See CUDA driver API `cuPointerGetAttribute` for more details.
transferred = true;
CUDADriver::get_instance().malloc(&device_buffers[i], arr_sz);
CUDADriver::get_instance().memcpy_host_to_device(
(void *)device_buffers[i], arg_buffers[i], arr_sz);
} else {
device_buffers[i] = arg_buffers[i];
}
// device_buffers[i] saves a raw ptr on CUDA device.
ctx_builder.set_arg_external_array(i, (uint64)device_buffers[i],
arr_sz,
/*is_device_allocation=*/false);

} else if (arr_sz > 0) {
// arg_buffers[i] is a DeviceAllocation*
// TODO: Unwraps DeviceAllocation* can be done at CodeGenLLVM since
// it's shared by cpu and cuda.
DeviceAllocation *ptr =
static_cast<DeviceAllocation *>(arg_buffers[i]);
device_buffers[i] = kernel->program->get_llvm_program_impl()
->get_ndarray_alloc_info_ptr(*ptr);
// We compare arg_buffers[i] and device_buffers[i] later to check
// if transfer happened.
// TODO: this logic can be improved but I'll leave it to a followup
// PR.
arg_buffers[i] = device_buffers[i];

// device_buffers[i] saves the unwrapped raw ptr from arg_buffers[i]
ctx_builder.set_arg_external_array(i, (uint64)device_buffers[i],
arr_sz,
/*is_device_allocation=*/false);
}
}
}
if (transferred) {
CUDADriver::get_instance().stream_synchronize(nullptr);
}
CUDAModuleToFunctionConverter converter{
tlctx, this->kernel->program->get_llvm_program_impl()};

for (auto task : offloaded_tasks) {
TI_TRACE("Launching kernel {}<<<{}, {}>>>", task.name, task.grid_dim,
task.block_dim);
cuda_module->launch(task.name, task.grid_dim, task.block_dim, 0,
{&context});
}
// copy data back to host
if (transferred) {
CUDADriver::get_instance().stream_synchronize(nullptr);
for (int i = 0; i < (int)args.size(); i++) {
if (device_buffers[i] != arg_buffers[i]) {
CUDADriver::get_instance().memcpy_device_to_host(
arg_buffers[i], (void *)device_buffers[i],
context.array_runtime_sizes[i]);
CUDADriver::get_instance().mem_free((void *)device_buffers[i]);
}
}
}
};
#else
TI_ERROR("No CUDA");
return nullptr;
#endif // TI_WITH_CUDA
return converter.convert(this->kernel, std::move(compiled_res.llvm_module),
std::move(compiled_res.offloaded_tasks));
}

llvm::Value *create_print(std::string tag,
Expand Down Expand Up @@ -934,9 +824,141 @@ class CodeGenLLVMCUDA : public CodeGenLLVM {
}
};

static void set_arg_external_array(RuntimeContext *ctx,
const std::string &kernel_name,
int arg_id,
uintptr_t ptr,
uint64 size,
bool is_device_allocation) {
ActionRecorder::get_instance().record(
"set_kernel_arg_ext_ptr",
{ActionArg("kernel_name", kernel_name), ActionArg("arg_id", arg_id),
ActionArg("address", fmt::format("0x{:x}", ptr)),
ActionArg("array_size_in_bytes", (int64)size)});

ctx->set_arg(arg_id, ptr);
ctx->set_array_runtime_size(arg_id, size);
ctx->set_array_is_device_allocation(arg_id, is_device_allocation);
}

FunctionType CodeGenCUDA::codegen() {
TI_AUTO_PROF
return CodeGenLLVMCUDA(kernel, ir).gen();
}

FunctionType CUDAModuleToFunctionConverter::convert(
const std::string &kernel_name,
const std::vector<LlvmLaunchArgInfo> &args,
std::unique_ptr<llvm::Module> mod,
std::vector<OffloadedTask> &&tasks) const {
#ifdef TI_WITH_CUDA
for (const auto &task : tasks) {
llvm::Function *func = mod->getFunction(task.name);
TI_ASSERT(func);
tlctx_->mark_function_as_cuda_kernel(func, task.block_dim);
}

auto jit = tlctx_->jit.get();
auto cuda_module =
jit->add_module(std::move(mode), program_->config->gpu_max_reg);

return [cuda_module, args, offloaded_tasks = tasks](RuntimeContext &context) {
CUDAContext::get_instance().make_current();
std::vector<void *> arg_buffers(args.size(), nullptr);
std::vector<void *> device_buffers(args.size(), nullptr);

bool transferred = false;
for (int i = 0; i < (int)args.size(); i++) {
if (args[i].is_array) {
const auto arr_sz = context.array_runtime_sizes[i];
if (arr_sz == 0) {
continue;
}
arg_buffers[i] = context.get_arg<void *>(i);
if (!context.is_device_allocations[i]) {
// Note: both numpy and PyTorch support arrays/tensors with zeros
// in shapes, e.g., shape=(0) or shape=(100, 0, 200). This makes
// `arr_sz` zero.
unsigned int attr_val = 0;
uint32_t ret_code = CUDADriver::get_instance().mem_get_attribute.call(
&attr_val, CU_POINTER_ATTRIBUTE_MEMORY_TYPE,
(void *)arg_buffers[i]);

if (ret_code != CUDA_SUCCESS || attr_val != CU_MEMORYTYPE_DEVICE) {
// Copy to device buffer if arg is on host
// - ret_code != CUDA_SUCCESS:
// arg_buffers[i] is not on device
// - attr_val != CU_MEMORYTYPE_DEVICE:
// Cuda driver is aware of arg_buffers[i] but it might be on
// host.
// See CUDA driver API `cuPointerGetAttribute` for more details.
transferred = true;
CUDADriver::get_instance().malloc(&device_buffers[i], arr_sz);
CUDADriver::get_instance().memcpy_host_to_device(
(void *)device_buffers[i], arg_buffers[i], arr_sz);
} else {
device_buffers[i] = arg_buffers[i];
}
// device_buffers[i] saves a raw ptr on CUDA device.
set_arg_external_array(&context, kernel_name, i,
(uint64)device_buffers[i], arr_sz,
/*is_device_allocation=*/false);

} else if (arr_sz > 0) {
// arg_buffers[i] is a DeviceAllocation*
// TODO: Unwraps DeviceAllocation* can be done at CodeGenLLVM since
// it's shared by cpu and cuda.
DeviceAllocation *ptr =
static_cast<DeviceAllocation *>(arg_buffers[i]);
device_buffers[i] = program_->get_ndarray_alloc_info_ptr(*ptr);
// We compare arg_buffers[i] and device_buffers[i] later to check
// if transfer happened.
// TODO: this logic can be improved but I'll leave it to a followup
// PR.
arg_buffers[i] = device_buffers[i];

// device_buffers[i] saves the unwrapped raw ptr from arg_buffers[i]
set_arg_external_array(&context, kernel_name, i,
(uint64)device_buffers[i], arr_sz,
/*is_device_allocation=*/false);
}
}
}
if (transferred) {
CUDADriver::get_instance().stream_synchronize(nullptr);
}

for (auto task : offloaded_tasks) {
TI_TRACE("Launching kernel {}<<<{}, {}>>>", task.name, task.grid_dim,
task.block_dim);
cuda_module->launch(task.name, task.grid_dim, task.block_dim, 0,
{&context});
}
// copy data back to host
if (transferred) {
CUDADriver::get_instance().stream_synchronize(nullptr);
for (int i = 0; i < (int)args.size(); i++) {
if (device_buffers[i] != arg_buffers[i]) {
CUDADriver::get_instance().memcpy_device_to_host(
arg_buffers[i], (void *)device_buffers[i],
context.array_runtime_sizes[i]);
CUDADriver::get_instance().mem_free((void *)device_buffers[i]);
}
}
}
};
#else
TI_ERROR("No CUDA");
return nullptr;
#endif // TI_WITH_CUDA
}

FunctionType CUDAModuleToFunctionConverter::convert(
const Kernel *kernel,
std::unique_ptr<llvm::Module> mod,
std::vector<OffloadedTask> &&tasks) const {
return convert(kernel->name, infer_launch_args(kernel), std::move(mod),
std::move(tasks));
}

TLANG_NAMESPACE_END
18 changes: 18 additions & 0 deletions taichi/backends/cuda/codegen_cuda.h
Original file line number Diff line number Diff line change
Expand Up @@ -3,6 +3,7 @@
#pragma once

#include "taichi/codegen/codegen.h"
#include "taichi/codegen/codegen_llvm.h"

TLANG_NAMESPACE_BEGIN

Expand All @@ -15,4 +16,21 @@ class CodeGenCUDA : public KernelCodeGen {
FunctionType codegen() override;
};

class CUDAModuleToFunctionConverter : public ModuleToFunctionConverter {
public:
explicit ModuleToFunctionConverter(TaichiLLVMContext *tlctx,
LlvmProgramImpl *program)
: ModuleToFunctionConverter(tlctx, program) {
}

FunctionType convert(const std::string &kernel_name,
const std::vector<LlvmLaunchArgInfo> &args,
std::unique_ptr<llvm::Module> mod,
std::vector<OffloadedTask> &&tasks) const override;

FunctionType convert(const Kernel *kernel,
std::unique_ptr<llvm::Module> mod,
std::vector<OffloadedTask> &&tasks) const override;
};

TLANG_NAMESPACE_END
9 changes: 5 additions & 4 deletions taichi/codegen/codegen_llvm.h
Original file line number Diff line number Diff line change
Expand Up @@ -413,7 +413,8 @@ class CodeGenLLVM : public IRVisitor, public LLVMModuleBuilder {

class LlvmProgramImpl;

// This is for CPU, we need one for CUDA (AMDGPU) as well.
// TODO: Make ModuleToFunctionConverter abstract,
// Move CPU implementation to "taichi/backend/cpu/"
class ModuleToFunctionConverter {
public:
explicit ModuleToFunctionConverter(TaichiLLVMContext *tlctx,
Expand All @@ -426,9 +427,9 @@ class ModuleToFunctionConverter {
std::unique_ptr<llvm::Module> mod,
std::vector<OffloadedTask> &&tasks) const;

FunctionType convert(const Kernel *kernel,
std::unique_ptr<llvm::Module> mod,
std::vector<OffloadedTask> &&tasks) const;
virtual FunctionType convert(const Kernel *kernel,
std::unique_ptr<llvm::Module> mod,
std::vector<OffloadedTask> &&tasks) const;

protected:
TaichiLLVMContext *tlctx_{nullptr};
Expand Down

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