bolt/deps/llvm-18.1.8/mlir/lib/Target/LLVM/NVVM/Target.cpp
2025-02-14 19:21:04 +01:00

603 lines
22 KiB
C++

//===- Target.cpp - MLIR LLVM NVVM target compilation -----------*- C++ -*-===//
//
// 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 files defines NVVM target related functions including registration
// calls for the `#nvvm.target` compilation attribute.
//
//===----------------------------------------------------------------------===//
#include "mlir/Target/LLVM/NVVM/Target.h"
#include "mlir/Dialect/GPU/IR/GPUDialect.h"
#include "mlir/Dialect/LLVMIR/NVVMDialect.h"
#include "mlir/Target/LLVM/NVVM/Utils.h"
#include "mlir/Target/LLVMIR/Dialect/GPU/GPUToLLVMIRTranslation.h"
#include "mlir/Target/LLVMIR/Dialect/LLVMIR/LLVMToLLVMIRTranslation.h"
#include "mlir/Target/LLVMIR/Dialect/NVVM/NVVMToLLVMIRTranslation.h"
#include "mlir/Target/LLVMIR/Export.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/FileUtilities.h"
#include "llvm/Support/FormatVariadic.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/Process.h"
#include "llvm/Support/Program.h"
#include "llvm/Support/TargetSelect.h"
#include <cstdlib>
using namespace mlir;
using namespace mlir::NVVM;
#ifndef __DEFAULT_CUDATOOLKIT_PATH__
#define __DEFAULT_CUDATOOLKIT_PATH__ ""
#endif
namespace {
// Implementation of the `TargetAttrInterface` model.
class NVVMTargetAttrImpl
: public gpu::TargetAttrInterface::FallbackModel<NVVMTargetAttrImpl> {
public:
std::optional<SmallVector<char, 0>>
serializeToObject(Attribute attribute, Operation *module,
const gpu::TargetOptions &options) const;
Attribute createObject(Attribute attribute,
const SmallVector<char, 0> &object,
const gpu::TargetOptions &options) const;
};
} // namespace
// Register the NVVM dialect, the NVVM translation & the target interface.
void mlir::NVVM::registerNVVMTargetInterfaceExternalModels(
DialectRegistry &registry) {
registry.addExtension(+[](MLIRContext *ctx, NVVM::NVVMDialect *dialect) {
NVVMTargetAttr::attachInterface<NVVMTargetAttrImpl>(*ctx);
});
}
void mlir::NVVM::registerNVVMTargetInterfaceExternalModels(
MLIRContext &context) {
DialectRegistry registry;
registerNVVMTargetInterfaceExternalModels(registry);
context.appendDialectRegistry(registry);
}
// Search for the CUDA toolkit path.
StringRef mlir::NVVM::getCUDAToolkitPath() {
if (const char *var = std::getenv("CUDA_ROOT"))
return var;
if (const char *var = std::getenv("CUDA_HOME"))
return var;
if (const char *var = std::getenv("CUDA_PATH"))
return var;
return __DEFAULT_CUDATOOLKIT_PATH__;
}
SerializeGPUModuleBase::SerializeGPUModuleBase(
Operation &module, NVVMTargetAttr target,
const gpu::TargetOptions &targetOptions)
: ModuleToObject(module, target.getTriple(), target.getChip(),
target.getFeatures(), target.getO()),
target(target), toolkitPath(targetOptions.getToolkitPath()),
fileList(targetOptions.getLinkFiles()) {
// If `targetOptions` have an empty toolkitPath use `getCUDAToolkitPath`
if (toolkitPath.empty())
toolkitPath = getCUDAToolkitPath();
// Append the files in the target attribute.
if (ArrayAttr files = target.getLink())
for (Attribute attr : files.getValue())
if (auto file = dyn_cast<StringAttr>(attr))
fileList.push_back(file.str());
// Append libdevice to the files to be loaded.
(void)appendStandardLibs();
}
void SerializeGPUModuleBase::init() {
static llvm::once_flag initializeBackendOnce;
llvm::call_once(initializeBackendOnce, []() {
// If the `NVPTX` LLVM target was built, initialize it.
#if LLVM_HAS_NVPTX_TARGET
LLVMInitializeNVPTXTarget();
LLVMInitializeNVPTXTargetInfo();
LLVMInitializeNVPTXTargetMC();
LLVMInitializeNVPTXAsmPrinter();
#endif
});
}
NVVMTargetAttr SerializeGPUModuleBase::getTarget() const { return target; }
StringRef SerializeGPUModuleBase::getToolkitPath() const { return toolkitPath; }
ArrayRef<std::string> SerializeGPUModuleBase::getFileList() const {
return fileList;
}
// Try to append `libdevice` from a CUDA toolkit installation.
LogicalResult SerializeGPUModuleBase::appendStandardLibs() {
StringRef pathRef = getToolkitPath();
if (!pathRef.empty()) {
SmallVector<char, 256> path;
path.insert(path.begin(), pathRef.begin(), pathRef.end());
pathRef = StringRef(path.data(), path.size());
if (!llvm::sys::fs::is_directory(pathRef)) {
getOperation().emitError() << "CUDA path: " << pathRef
<< " does not exist or is not a directory.\n";
return failure();
}
llvm::sys::path::append(path, "nvvm", "libdevice", "libdevice.10.bc");
pathRef = StringRef(path.data(), path.size());
if (!llvm::sys::fs::is_regular_file(pathRef)) {
getOperation().emitError() << "LibDevice path: " << pathRef
<< " does not exist or is not a file.\n";
return failure();
}
fileList.push_back(pathRef.str());
}
return success();
}
std::optional<SmallVector<std::unique_ptr<llvm::Module>>>
SerializeGPUModuleBase::loadBitcodeFiles(llvm::Module &module) {
SmallVector<std::unique_ptr<llvm::Module>> bcFiles;
if (failed(loadBitcodeFilesFromList(module.getContext(), fileList, bcFiles,
true)))
return std::nullopt;
return std::move(bcFiles);
}
#if MLIR_CUDA_CONVERSIONS_ENABLED == 1
namespace {
class NVPTXSerializer : public SerializeGPUModuleBase {
public:
NVPTXSerializer(Operation &module, NVVMTargetAttr target,
const gpu::TargetOptions &targetOptions);
gpu::GPUModuleOp getOperation();
// Compile PTX to cubin using `ptxas`.
std::optional<SmallVector<char, 0>>
compileToBinary(const std::string &ptxCode);
// Compile PTX to cubin using the `nvptxcompiler` library.
std::optional<SmallVector<char, 0>>
compileToBinaryNVPTX(const std::string &ptxCode);
std::optional<SmallVector<char, 0>>
moduleToObject(llvm::Module &llvmModule) override;
private:
using TmpFile = std::pair<llvm::SmallString<128>, llvm::FileRemover>;
// Create a temp file.
std::optional<TmpFile> createTemp(StringRef name, StringRef suffix);
// Find the `tool` path, where `tool` is the name of the binary to search,
// i.e. `ptxas` or `fatbinary`. The search order is:
// 1. The toolkit path in `targetOptions`.
// 2. In the system PATH.
// 3. The path from `getCUDAToolkitPath()`.
std::optional<std::string> findTool(StringRef tool);
// Target options.
gpu::TargetOptions targetOptions;
};
} // namespace
NVPTXSerializer::NVPTXSerializer(Operation &module, NVVMTargetAttr target,
const gpu::TargetOptions &targetOptions)
: SerializeGPUModuleBase(module, target, targetOptions),
targetOptions(targetOptions) {}
std::optional<NVPTXSerializer::TmpFile>
NVPTXSerializer::createTemp(StringRef name, StringRef suffix) {
llvm::SmallString<128> filename;
std::error_code ec =
llvm::sys::fs::createTemporaryFile(name, suffix, filename);
if (ec) {
getOperation().emitError() << "Couldn't create the temp file: `" << filename
<< "`, error message: " << ec.message();
return std::nullopt;
}
return TmpFile(filename, llvm::FileRemover(filename.c_str()));
}
gpu::GPUModuleOp NVPTXSerializer::getOperation() {
return dyn_cast<gpu::GPUModuleOp>(&SerializeGPUModuleBase::getOperation());
}
std::optional<std::string> NVPTXSerializer::findTool(StringRef tool) {
// Find the `tool` path.
// 1. Check the toolkit path given in the command line.
StringRef pathRef = targetOptions.getToolkitPath();
SmallVector<char, 256> path;
if (pathRef.size()) {
path.insert(path.begin(), pathRef.begin(), pathRef.end());
llvm::sys::path::append(path, "bin", tool);
if (llvm::sys::fs::can_execute(path))
return StringRef(path.data(), path.size()).str();
}
// 2. Check PATH.
if (std::optional<std::string> toolPath =
llvm::sys::Process::FindInEnvPath("PATH", tool))
return *toolPath;
// 3. Check `getCUDAToolkitPath()`.
pathRef = getCUDAToolkitPath();
path.clear();
if (pathRef.size()) {
path.insert(path.begin(), pathRef.begin(), pathRef.end());
llvm::sys::path::append(path, "bin", tool);
if (llvm::sys::fs::can_execute(path))
return StringRef(path.data(), path.size()).str();
}
getOperation().emitError()
<< "Couldn't find the `" << tool
<< "` binary. Please specify the toolkit "
"path, add the compiler to $PATH, or set one of the environment "
"variables in `NVVM::getCUDAToolkitPath()`.";
return std::nullopt;
}
// TODO: clean this method & have a generic tool driver or never emit binaries
// with this mechanism and let another stage take care of it.
std::optional<SmallVector<char, 0>>
NVPTXSerializer::compileToBinary(const std::string &ptxCode) {
// Determine if the serializer should create a fatbinary with the PTX embeded
// or a simple CUBIN binary.
const bool createFatbin =
targetOptions.getCompilationTarget() == gpu::CompilationTarget::Fatbin;
// Find the `ptxas` & `fatbinary` tools.
std::optional<std::string> ptxasCompiler = findTool("ptxas");
if (!ptxasCompiler)
return std::nullopt;
std::optional<std::string> fatbinaryTool = findTool("fatbinary");
if (createFatbin && !fatbinaryTool)
return std::nullopt;
Location loc = getOperation().getLoc();
// Base name for all temp files: mlir-<module name>-<target triple>-<chip>.
std::string basename =
llvm::formatv("mlir-{0}-{1}-{2}", getOperation().getNameAttr().getValue(),
getTarget().getTriple(), getTarget().getChip());
// Create temp files:
std::optional<TmpFile> ptxFile = createTemp(basename, "ptx");
if (!ptxFile)
return std::nullopt;
std::optional<TmpFile> logFile = createTemp(basename, "log");
if (!logFile)
return std::nullopt;
std::optional<TmpFile> binaryFile = createTemp(basename, "bin");
if (!binaryFile)
return std::nullopt;
TmpFile cubinFile;
if (createFatbin) {
Twine cubinFilename = ptxFile->first + ".cubin";
cubinFile = TmpFile(cubinFilename.str(), llvm::FileRemover(cubinFilename));
} else {
cubinFile.first = binaryFile->first;
}
std::error_code ec;
// Dump the PTX to a temp file.
{
llvm::raw_fd_ostream ptxStream(ptxFile->first, ec);
if (ec) {
emitError(loc) << "Couldn't open the file: `" << ptxFile->first
<< "`, error message: " << ec.message();
return std::nullopt;
}
ptxStream << ptxCode;
if (ptxStream.has_error()) {
emitError(loc) << "An error occurred while writing the PTX to: `"
<< ptxFile->first << "`.";
return std::nullopt;
}
ptxStream.flush();
}
// Command redirects.
std::optional<StringRef> redirects[] = {
std::nullopt,
logFile->first,
logFile->first,
};
// Get any extra args passed in `targetOptions`.
std::pair<llvm::BumpPtrAllocator, SmallVector<const char *>> cmdOpts =
targetOptions.tokenizeCmdOptions();
// Create ptxas args.
std::string optLevel = std::to_string(this->optLevel);
SmallVector<StringRef, 12> ptxasArgs(
{StringRef("ptxas"), StringRef("-arch"), getTarget().getChip(),
StringRef(ptxFile->first), StringRef("-o"), StringRef(cubinFile.first),
"--opt-level", optLevel});
bool useFatbin32 = false;
for (auto cArg : cmdOpts.second) {
// All `cmdOpts` are for `ptxas` except `-32` which passes `-32` to
// `fatbinary`, indicating a 32-bit target. By default a 64-bit target is
// assumed.
if (StringRef arg(cArg); arg != "-32")
ptxasArgs.push_back(arg);
else
useFatbin32 = true;
}
// Create the `fatbinary` args.
StringRef chip = getTarget().getChip();
// Remove the arch prefix to obtain the compute capability.
chip.consume_front("sm_"), chip.consume_front("compute_");
// Embed the cubin object.
std::string cubinArg =
llvm::formatv("--image3=kind=elf,sm={0},file={1}", chip, cubinFile.first)
.str();
// Embed the PTX file so the driver can JIT if needed.
std::string ptxArg =
llvm::formatv("--image3=kind=ptx,sm={0},file={1}", chip, ptxFile->first)
.str();
SmallVector<StringRef, 6> fatbinArgs({StringRef("fatbinary"),
useFatbin32 ? "-32" : "-64", cubinArg,
ptxArg, "--create", binaryFile->first});
// Dump tool invocation commands.
#define DEBUG_TYPE "serialize-to-binary"
LLVM_DEBUG({
llvm::dbgs() << "Tool invocation for module: "
<< getOperation().getNameAttr() << "\n";
llvm::interleave(ptxasArgs, llvm::dbgs(), " ");
llvm::dbgs() << "\n";
if (createFatbin) {
llvm::interleave(fatbinArgs, llvm::dbgs(), " ");
llvm::dbgs() << "\n";
}
});
#undef DEBUG_TYPE
// Helper function for printing tool error logs.
std::string message;
auto emitLogError =
[&](StringRef toolName) -> std::optional<SmallVector<char, 0>> {
if (message.empty()) {
llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> toolStderr =
llvm::MemoryBuffer::getFile(logFile->first);
if (toolStderr)
emitError(loc) << toolName << " invocation failed. Log:\n"
<< toolStderr->get()->getBuffer();
else
emitError(loc) << toolName << " invocation failed.";
return std::nullopt;
}
emitError(loc) << toolName
<< " invocation failed, error message: " << message;
return std::nullopt;
};
// Invoke PTXAS.
if (llvm::sys::ExecuteAndWait(ptxasCompiler.value(), ptxasArgs,
/*Env=*/std::nullopt,
/*Redirects=*/redirects,
/*SecondsToWait=*/0,
/*MemoryLimit=*/0,
/*ErrMsg=*/&message))
return emitLogError("`ptxas`");
// Invoke `fatbin`.
message.clear();
if (createFatbin && llvm::sys::ExecuteAndWait(*fatbinaryTool, fatbinArgs,
/*Env=*/std::nullopt,
/*Redirects=*/redirects,
/*SecondsToWait=*/0,
/*MemoryLimit=*/0,
/*ErrMsg=*/&message))
return emitLogError("`fatbinary`");
// Dump the output of the tools, helpful if the verbose flag was passed.
#define DEBUG_TYPE "serialize-to-binary"
LLVM_DEBUG({
llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> logBuffer =
llvm::MemoryBuffer::getFile(logFile->first);
if (logBuffer && (*logBuffer)->getBuffer().size()) {
llvm::dbgs() << "Output:\n" << (*logBuffer)->getBuffer() << "\n";
llvm::dbgs().flush();
}
});
#undef DEBUG_TYPE
// Read the fatbin.
llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> binaryBuffer =
llvm::MemoryBuffer::getFile(binaryFile->first);
if (!binaryBuffer) {
emitError(loc) << "Couldn't open the file: `" << binaryFile->first
<< "`, error message: " << binaryBuffer.getError().message();
return std::nullopt;
}
StringRef fatbin = (*binaryBuffer)->getBuffer();
return SmallVector<char, 0>(fatbin.begin(), fatbin.end());
}
#if MLIR_NVPTXCOMPILER_ENABLED == 1
#include "nvPTXCompiler.h"
#define RETURN_ON_NVPTXCOMPILER_ERROR(expr) \
do { \
if (auto status = (expr)) { \
emitError(loc) << llvm::Twine(#expr).concat(" failed with error code ") \
<< status; \
return std::nullopt; \
} \
} while (false)
std::optional<SmallVector<char, 0>>
NVPTXSerializer::compileToBinaryNVPTX(const std::string &ptxCode) {
Location loc = getOperation().getLoc();
nvPTXCompilerHandle compiler = nullptr;
nvPTXCompileResult status;
size_t logSize;
// Create the options.
std::string optLevel = std::to_string(this->optLevel);
std::pair<llvm::BumpPtrAllocator, SmallVector<const char *>> cmdOpts =
targetOptions.tokenizeCmdOptions();
cmdOpts.second.append(
{"-arch", getTarget().getChip().data(), "--opt-level", optLevel.c_str()});
// Create the compiler handle.
RETURN_ON_NVPTXCOMPILER_ERROR(
nvPTXCompilerCreate(&compiler, ptxCode.size(), ptxCode.c_str()));
// Try to compile the binary.
status = nvPTXCompilerCompile(compiler, cmdOpts.second.size(),
cmdOpts.second.data());
// Check if compilation failed.
if (status != NVPTXCOMPILE_SUCCESS) {
RETURN_ON_NVPTXCOMPILER_ERROR(
nvPTXCompilerGetErrorLogSize(compiler, &logSize));
if (logSize != 0) {
SmallVector<char> log(logSize + 1, 0);
RETURN_ON_NVPTXCOMPILER_ERROR(
nvPTXCompilerGetErrorLog(compiler, log.data()));
emitError(loc) << "NVPTX compiler invocation failed, error log: "
<< log.data();
} else
emitError(loc) << "NVPTX compiler invocation failed with error code: "
<< status;
return std::nullopt;
}
// Retrieve the binary.
size_t elfSize;
RETURN_ON_NVPTXCOMPILER_ERROR(
nvPTXCompilerGetCompiledProgramSize(compiler, &elfSize));
SmallVector<char, 0> binary(elfSize, 0);
RETURN_ON_NVPTXCOMPILER_ERROR(
nvPTXCompilerGetCompiledProgram(compiler, (void *)binary.data()));
// Dump the log of the compiler, helpful if the verbose flag was passed.
#define DEBUG_TYPE "serialize-to-binary"
LLVM_DEBUG({
RETURN_ON_NVPTXCOMPILER_ERROR(
nvPTXCompilerGetInfoLogSize(compiler, &logSize));
if (logSize != 0) {
SmallVector<char> log(logSize + 1, 0);
RETURN_ON_NVPTXCOMPILER_ERROR(
nvPTXCompilerGetInfoLog(compiler, log.data()));
llvm::dbgs() << "NVPTX compiler invocation for module: "
<< getOperation().getNameAttr() << "\n";
llvm::dbgs() << "Arguments: ";
llvm::interleave(cmdOpts.second, llvm::dbgs(), " ");
llvm::dbgs() << "\nOutput\n" << log.data() << "\n";
llvm::dbgs().flush();
}
});
#undef DEBUG_TYPE
RETURN_ON_NVPTXCOMPILER_ERROR(nvPTXCompilerDestroy(&compiler));
return binary;
}
#endif // MLIR_NVPTXCOMPILER_ENABLED == 1
std::optional<SmallVector<char, 0>>
NVPTXSerializer::moduleToObject(llvm::Module &llvmModule) {
// Return LLVM IR if the compilation target is offload.
#define DEBUG_TYPE "serialize-to-llvm"
LLVM_DEBUG({
llvm::dbgs() << "LLVM IR for module: " << getOperation().getNameAttr()
<< "\n";
llvm::dbgs() << llvmModule << "\n";
llvm::dbgs().flush();
});
#undef DEBUG_TYPE
if (targetOptions.getCompilationTarget() == gpu::CompilationTarget::Offload)
return SerializeGPUModuleBase::moduleToObject(llvmModule);
// Emit PTX code.
std::optional<llvm::TargetMachine *> targetMachine =
getOrCreateTargetMachine();
if (!targetMachine) {
getOperation().emitError() << "Target Machine unavailable for triple "
<< triple << ", can't optimize with LLVM\n";
return std::nullopt;
}
std::optional<std::string> serializedISA =
translateToISA(llvmModule, **targetMachine);
if (!serializedISA) {
getOperation().emitError() << "Failed translating the module to ISA.";
return std::nullopt;
}
#define DEBUG_TYPE "serialize-to-isa"
LLVM_DEBUG({
llvm::dbgs() << "PTX for module: " << getOperation().getNameAttr() << "\n";
llvm::dbgs() << *serializedISA << "\n";
llvm::dbgs().flush();
});
#undef DEBUG_TYPE
// Return PTX if the compilation target is assembly.
if (targetOptions.getCompilationTarget() ==
gpu::CompilationTarget::Assembly) {
// Make sure to include the null terminator.
StringRef bin(serializedISA->c_str(), serializedISA->size() + 1);
return SmallVector<char, 0>(bin.begin(), bin.end());
}
// Compile to binary.
#if MLIR_NVPTXCOMPILER_ENABLED == 1
return compileToBinaryNVPTX(*serializedISA);
#else
return compileToBinary(*serializedISA);
#endif // MLIR_NVPTXCOMPILER_ENABLED == 1
}
#endif // MLIR_CUDA_CONVERSIONS_ENABLED == 1
std::optional<SmallVector<char, 0>>
NVVMTargetAttrImpl::serializeToObject(Attribute attribute, Operation *module,
const gpu::TargetOptions &options) const {
assert(module && "The module must be non null.");
if (!module)
return std::nullopt;
if (!mlir::isa<gpu::GPUModuleOp>(module)) {
module->emitError("Module must be a GPU module.");
return std::nullopt;
}
#if MLIR_CUDA_CONVERSIONS_ENABLED == 1
NVPTXSerializer serializer(*module, cast<NVVMTargetAttr>(attribute), options);
serializer.init();
return serializer.run();
#else
module->emitError(
"The `NVPTX` target was not built. Please enable it when building LLVM.");
return std::nullopt;
#endif // MLIR_CUDA_CONVERSIONS_ENABLED == 1
}
Attribute
NVVMTargetAttrImpl::createObject(Attribute attribute,
const SmallVector<char, 0> &object,
const gpu::TargetOptions &options) const {
auto target = cast<NVVMTargetAttr>(attribute);
gpu::CompilationTarget format = options.getCompilationTarget();
DictionaryAttr objectProps;
Builder builder(attribute.getContext());
if (format == gpu::CompilationTarget::Assembly)
objectProps = builder.getDictionaryAttr(
{builder.getNamedAttr("O", builder.getI32IntegerAttr(target.getO()))});
return builder.getAttr<gpu::ObjectAttr>(
attribute, format,
builder.getStringAttr(StringRef(object.data(), object.size())),
objectProps);
}