bolt/deps/llvm-18.1.8/mlir/lib/Target/LLVMIR/Dialect/GPU/SelectObjectAttr.cpp
2025-02-14 19:21:04 +01:00

464 lines
17 KiB
C++

//===- ObjectHandler.cpp - Implements base ObjectManager attributes -------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements the `OffloadingLLVMTranslationAttrInterface` for the
// `SelectObject` attribute.
//
//===----------------------------------------------------------------------===//
#include "mlir/Dialect/GPU/IR/GPUDialect.h"
#include "mlir/Target/LLVMIR/Dialect/GPU/GPUToLLVMIRTranslation.h"
#include "mlir/Target/LLVMIR/Export.h"
#include "mlir/Target/LLVMIR/ModuleTranslation.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/FormatVariadic.h"
using namespace mlir;
namespace {
// Implementation of the `OffloadingLLVMTranslationAttrInterface` model.
class SelectObjectAttrImpl
: public gpu::OffloadingLLVMTranslationAttrInterface::FallbackModel<
SelectObjectAttrImpl> {
public:
// Translates a `gpu.binary`, embedding the binary into a host LLVM module as
// global binary string.
LogicalResult embedBinary(Attribute attribute, Operation *operation,
llvm::IRBuilderBase &builder,
LLVM::ModuleTranslation &moduleTranslation) const;
// Translates a `gpu.launch_func` to a sequence of LLVM instructions resulting
// in a kernel launch call.
LogicalResult launchKernel(Attribute attribute,
Operation *launchFuncOperation,
Operation *binaryOperation,
llvm::IRBuilderBase &builder,
LLVM::ModuleTranslation &moduleTranslation) const;
// Returns the selected object for embedding.
gpu::ObjectAttr getSelectedObject(gpu::BinaryOp op) const;
};
// Returns an identifier for the global string holding the binary.
std::string getBinaryIdentifier(StringRef binaryName) {
return binaryName.str() + "_bin_cst";
}
} // namespace
void mlir::gpu::registerOffloadingLLVMTranslationInterfaceExternalModels(
DialectRegistry &registry) {
registry.addExtension(+[](MLIRContext *ctx, gpu::GPUDialect *dialect) {
SelectObjectAttr::attachInterface<SelectObjectAttrImpl>(*ctx);
});
}
gpu::ObjectAttr
SelectObjectAttrImpl::getSelectedObject(gpu::BinaryOp op) const {
ArrayRef<Attribute> objects = op.getObjectsAttr().getValue();
// Obtain the index of the object to select.
int64_t index = -1;
if (Attribute target =
cast<gpu::SelectObjectAttr>(op.getOffloadingHandlerAttr())
.getTarget()) {
// If the target attribute is a number it is the index. Otherwise compare
// the attribute to every target inside the object array to find the index.
if (auto indexAttr = mlir::dyn_cast<IntegerAttr>(target)) {
index = indexAttr.getInt();
} else {
for (auto [i, attr] : llvm::enumerate(objects)) {
auto obj = mlir::dyn_cast<gpu::ObjectAttr>(attr);
if (obj.getTarget() == target) {
index = i;
}
}
}
} else {
// If the target attribute is null then it's selecting the first object in
// the object array.
index = 0;
}
if (index < 0 || index >= static_cast<int64_t>(objects.size())) {
op->emitError("the requested target object couldn't be found");
return nullptr;
}
return mlir::dyn_cast<gpu::ObjectAttr>(objects[index]);
}
LogicalResult SelectObjectAttrImpl::embedBinary(
Attribute attribute, Operation *operation, llvm::IRBuilderBase &builder,
LLVM::ModuleTranslation &moduleTranslation) const {
assert(operation && "The binary operation must be non null.");
if (!operation)
return failure();
auto op = mlir::dyn_cast<gpu::BinaryOp>(operation);
if (!op) {
operation->emitError("operation must be a GPU binary");
return failure();
}
gpu::ObjectAttr object = getSelectedObject(op);
if (!object)
return failure();
llvm::Module *module = moduleTranslation.getLLVMModule();
// Embed the object as a global string.
llvm::Constant *binary = llvm::ConstantDataArray::getString(
builder.getContext(), object.getObject().getValue(), false);
llvm::GlobalVariable *serializedObj =
new llvm::GlobalVariable(*module, binary->getType(), true,
llvm::GlobalValue::LinkageTypes::InternalLinkage,
binary, getBinaryIdentifier(op.getName()));
serializedObj->setLinkage(llvm::GlobalValue::LinkageTypes::InternalLinkage);
serializedObj->setAlignment(llvm::MaybeAlign(8));
serializedObj->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::None);
return success();
}
namespace llvm {
namespace {
class LaunchKernel {
public:
LaunchKernel(Module &module, IRBuilderBase &builder,
mlir::LLVM::ModuleTranslation &moduleTranslation);
// Get the kernel launch callee.
FunctionCallee getKernelLaunchFn();
// Get the kernel launch callee.
FunctionCallee getClusterKernelLaunchFn();
// Get the module function callee.
FunctionCallee getModuleFunctionFn();
// Get the module load callee.
FunctionCallee getModuleLoadFn();
// Get the module load JIT callee.
FunctionCallee getModuleLoadJITFn();
// Get the module unload callee.
FunctionCallee getModuleUnloadFn();
// Get the stream create callee.
FunctionCallee getStreamCreateFn();
// Get the stream destroy callee.
FunctionCallee getStreamDestroyFn();
// Get the stream sync callee.
FunctionCallee getStreamSyncFn();
// Ger or create the function name global string.
Value *getOrCreateFunctionName(StringRef moduleName, StringRef kernelName);
// Create the void* kernel array for passing the arguments.
Value *createKernelArgArray(mlir::gpu::LaunchFuncOp op);
// Create the full kernel launch.
mlir::LogicalResult createKernelLaunch(mlir::gpu::LaunchFuncOp op,
mlir::gpu::ObjectAttr object);
private:
Module &module;
IRBuilderBase &builder;
mlir::LLVM::ModuleTranslation &moduleTranslation;
Type *i32Ty{};
Type *i64Ty{};
Type *voidTy{};
Type *intPtrTy{};
PointerType *ptrTy{};
};
} // namespace
} // namespace llvm
LogicalResult SelectObjectAttrImpl::launchKernel(
Attribute attribute, Operation *launchFuncOperation,
Operation *binaryOperation, llvm::IRBuilderBase &builder,
LLVM::ModuleTranslation &moduleTranslation) const {
assert(launchFuncOperation && "The launch func operation must be non null.");
if (!launchFuncOperation)
return failure();
auto launchFuncOp = mlir::dyn_cast<gpu::LaunchFuncOp>(launchFuncOperation);
if (!launchFuncOp) {
launchFuncOperation->emitError("operation must be a GPU launch func Op.");
return failure();
}
auto binOp = mlir::dyn_cast<gpu::BinaryOp>(binaryOperation);
if (!binOp) {
binaryOperation->emitError("operation must be a GPU binary.");
return failure();
}
gpu::ObjectAttr object = getSelectedObject(binOp);
if (!object)
return failure();
return llvm::LaunchKernel(*moduleTranslation.getLLVMModule(), builder,
moduleTranslation)
.createKernelLaunch(launchFuncOp, object);
}
llvm::LaunchKernel::LaunchKernel(
Module &module, IRBuilderBase &builder,
mlir::LLVM::ModuleTranslation &moduleTranslation)
: module(module), builder(builder), moduleTranslation(moduleTranslation) {
i32Ty = builder.getInt32Ty();
i64Ty = builder.getInt64Ty();
ptrTy = builder.getPtrTy(0);
voidTy = builder.getVoidTy();
intPtrTy = builder.getIntPtrTy(module.getDataLayout());
}
llvm::FunctionCallee llvm::LaunchKernel::getKernelLaunchFn() {
return module.getOrInsertFunction(
"mgpuLaunchKernel",
FunctionType::get(voidTy,
ArrayRef<Type *>({ptrTy, intPtrTy, intPtrTy, intPtrTy,
intPtrTy, intPtrTy, intPtrTy, i32Ty,
ptrTy, ptrTy, ptrTy, i64Ty}),
false));
}
llvm::FunctionCallee llvm::LaunchKernel::getClusterKernelLaunchFn() {
return module.getOrInsertFunction(
"mgpuLaunchClusterKernel",
FunctionType::get(
voidTy,
ArrayRef<Type *>({ptrTy, intPtrTy, intPtrTy, intPtrTy, intPtrTy,
intPtrTy, intPtrTy, intPtrTy, intPtrTy, intPtrTy,
i32Ty, ptrTy, ptrTy, ptrTy}),
false));
}
llvm::FunctionCallee llvm::LaunchKernel::getModuleFunctionFn() {
return module.getOrInsertFunction(
"mgpuModuleGetFunction",
FunctionType::get(ptrTy, ArrayRef<Type *>({ptrTy, ptrTy}), false));
}
llvm::FunctionCallee llvm::LaunchKernel::getModuleLoadFn() {
return module.getOrInsertFunction(
"mgpuModuleLoad",
FunctionType::get(ptrTy, ArrayRef<Type *>({ptrTy, i64Ty}), false));
}
llvm::FunctionCallee llvm::LaunchKernel::getModuleLoadJITFn() {
return module.getOrInsertFunction(
"mgpuModuleLoadJIT",
FunctionType::get(ptrTy, ArrayRef<Type *>({ptrTy, i32Ty}), false));
}
llvm::FunctionCallee llvm::LaunchKernel::getModuleUnloadFn() {
return module.getOrInsertFunction(
"mgpuModuleUnload",
FunctionType::get(voidTy, ArrayRef<Type *>({ptrTy}), false));
}
llvm::FunctionCallee llvm::LaunchKernel::getStreamCreateFn() {
return module.getOrInsertFunction("mgpuStreamCreate",
FunctionType::get(ptrTy, false));
}
llvm::FunctionCallee llvm::LaunchKernel::getStreamDestroyFn() {
return module.getOrInsertFunction(
"mgpuStreamDestroy",
FunctionType::get(voidTy, ArrayRef<Type *>({ptrTy}), false));
}
llvm::FunctionCallee llvm::LaunchKernel::getStreamSyncFn() {
return module.getOrInsertFunction(
"mgpuStreamSynchronize",
FunctionType::get(voidTy, ArrayRef<Type *>({ptrTy}), false));
}
// Generates an LLVM IR dialect global that contains the name of the given
// kernel function as a C string, and returns a pointer to its beginning.
llvm::Value *llvm::LaunchKernel::getOrCreateFunctionName(StringRef moduleName,
StringRef kernelName) {
std::string globalName =
std::string(formatv("{0}_{1}_kernel_name", moduleName, kernelName));
if (GlobalVariable *gv = module.getGlobalVariable(globalName))
return gv;
return builder.CreateGlobalString(kernelName, globalName);
}
// Creates a struct containing all kernel parameters on the stack and returns
// an array of type-erased pointers to the fields of the struct. The array can
// then be passed to the CUDA / ROCm (HIP) kernel launch calls.
// The generated code is essentially as follows:
//
// %struct = alloca(sizeof(struct { Parameters... }))
// %array = alloca(NumParameters * sizeof(void *))
// for (i : [0, NumParameters))
// %fieldPtr = llvm.getelementptr %struct[0, i]
// llvm.store parameters[i], %fieldPtr
// %elementPtr = llvm.getelementptr %array[i]
// llvm.store %fieldPtr, %elementPtr
// return %array
llvm::Value *
llvm::LaunchKernel::createKernelArgArray(mlir::gpu::LaunchFuncOp op) {
SmallVector<Value *> args =
moduleTranslation.lookupValues(op.getKernelOperands());
SmallVector<Type *> structTypes(args.size(), nullptr);
for (auto [i, arg] : llvm::enumerate(args))
structTypes[i] = arg->getType();
Type *structTy = StructType::create(module.getContext(), structTypes);
Value *argStruct = builder.CreateAlloca(structTy, 0u);
Value *argArray = builder.CreateAlloca(
ptrTy, ConstantInt::get(intPtrTy, structTypes.size()));
for (auto [i, arg] : enumerate(args)) {
Value *structMember = builder.CreateStructGEP(structTy, argStruct, i);
builder.CreateStore(arg, structMember);
Value *arrayMember = builder.CreateConstGEP1_32(ptrTy, argArray, i);
builder.CreateStore(structMember, arrayMember);
}
return argArray;
}
// Emits LLVM IR to launch a kernel function:
// %0 = call %binarygetter
// %1 = call %moduleLoad(%0)
// %2 = <see generateKernelNameConstant>
// %3 = call %moduleGetFunction(%1, %2)
// %4 = call %streamCreate()
// %5 = <see generateParamsArray>
// call %launchKernel(%3, <launchOp operands 0..5>, 0, %4, %5, nullptr)
// call %streamSynchronize(%4)
// call %streamDestroy(%4)
// call %moduleUnload(%1)
mlir::LogicalResult
llvm::LaunchKernel::createKernelLaunch(mlir::gpu::LaunchFuncOp op,
mlir::gpu::ObjectAttr object) {
auto llvmValue = [&](mlir::Value value) -> Value * {
Value *v = moduleTranslation.lookupValue(value);
assert(v && "Value has not been translated.");
return v;
};
// Get grid dimensions.
mlir::gpu::KernelDim3 grid = op.getGridSizeOperandValues();
Value *gx = llvmValue(grid.x), *gy = llvmValue(grid.y),
*gz = llvmValue(grid.z);
// Get block dimensions.
mlir::gpu::KernelDim3 block = op.getBlockSizeOperandValues();
Value *bx = llvmValue(block.x), *by = llvmValue(block.y),
*bz = llvmValue(block.z);
// Get dynamic shared memory size.
Value *dynamicMemorySize = nullptr;
if (mlir::Value dynSz = op.getDynamicSharedMemorySize())
dynamicMemorySize = llvmValue(dynSz);
else
dynamicMemorySize = ConstantInt::get(i32Ty, 0);
// Create the argument array.
Value *argArray = createKernelArgArray(op);
// Default JIT optimization level.
llvm::Constant *optV = llvm::ConstantInt::get(i32Ty, 0);
// Check if there's an optimization level embedded in the object.
DictionaryAttr objectProps = object.getProperties();
mlir::Attribute optAttr;
if (objectProps && (optAttr = objectProps.get("O"))) {
auto optLevel = dyn_cast<IntegerAttr>(optAttr);
if (!optLevel)
return op.emitError("the optimization level must be an integer");
optV = llvm::ConstantInt::get(i32Ty, optLevel.getValue());
}
// Load the kernel module.
StringRef moduleName = op.getKernelModuleName().getValue();
std::string binaryIdentifier = getBinaryIdentifier(moduleName);
Value *binary = module.getGlobalVariable(binaryIdentifier, true);
if (!binary)
return op.emitError() << "Couldn't find the binary: " << binaryIdentifier;
auto binaryVar = dyn_cast<llvm::GlobalVariable>(binary);
if (!binaryVar)
return op.emitError() << "Binary is not a global variable: "
<< binaryIdentifier;
llvm::Constant *binaryInit = binaryVar->getInitializer();
auto binaryDataSeq =
dyn_cast_if_present<llvm::ConstantDataSequential>(binaryInit);
if (!binaryDataSeq)
return op.emitError() << "Couldn't find binary data array: "
<< binaryIdentifier;
llvm::Constant *binarySize =
llvm::ConstantInt::get(i64Ty, binaryDataSeq->getNumElements() *
binaryDataSeq->getElementByteSize());
Value *moduleObject =
object.getFormat() == gpu::CompilationTarget::Assembly
? builder.CreateCall(getModuleLoadJITFn(), {binary, optV})
: builder.CreateCall(getModuleLoadFn(), {binary, binarySize});
// Load the kernel function.
Value *moduleFunction = builder.CreateCall(
getModuleFunctionFn(),
{moduleObject,
getOrCreateFunctionName(moduleName, op.getKernelName().getValue())});
// Get the stream to use for execution. If there's no async object then create
// a stream to make a synchronous kernel launch.
Value *stream = nullptr;
bool handleStream = false;
if (mlir::Value asyncObject = op.getAsyncObject()) {
stream = llvmValue(asyncObject);
} else {
handleStream = true;
stream = builder.CreateCall(getStreamCreateFn(), {});
}
llvm::Constant *paramsCount =
llvm::ConstantInt::get(i64Ty, op.getNumKernelOperands());
// Create the launch call.
Value *nullPtr = ConstantPointerNull::get(ptrTy);
// Launch kernel with clusters if cluster size is specified.
if (op.hasClusterSize()) {
mlir::gpu::KernelDim3 cluster = op.getClusterSizeOperandValues();
Value *cx = llvmValue(cluster.x), *cy = llvmValue(cluster.y),
*cz = llvmValue(cluster.z);
builder.CreateCall(
getClusterKernelLaunchFn(),
ArrayRef<Value *>({moduleFunction, cx, cy, cz, gx, gy, gz, bx, by, bz,
dynamicMemorySize, stream, argArray, nullPtr}));
} else {
builder.CreateCall(getKernelLaunchFn(),
ArrayRef<Value *>({moduleFunction, gx, gy, gz, bx, by,
bz, dynamicMemorySize, stream,
argArray, nullPtr, paramsCount}));
}
// Sync & destroy the stream, for synchronous launches.
if (handleStream) {
builder.CreateCall(getStreamSyncFn(), {stream});
builder.CreateCall(getStreamDestroyFn(), {stream});
}
// Unload the kernel module.
builder.CreateCall(getModuleUnloadFn(), {moduleObject});
return success();
}