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//===- AMDGPUOpenMP.cpp - AMDGPUOpenMP ToolChain Implementation -*- C++ -*-===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#include "AMDGPUOpenMP.h"
#include "AMDGPU.h"
#include "CommonArgs.h"
#include "ToolChains/ROCm.h"
#include "clang/Basic/DiagnosticDriver.h"
#include "clang/Driver/Compilation.h"
#include "clang/Driver/Driver.h"
#include "clang/Driver/DriverDiagnostic.h"
#include "clang/Driver/InputInfo.h"
#include "clang/Driver/Options.h"
#include "clang/Driver/Tool.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/FormatAdapters.h"
#include "llvm/Support/FormatVariadic.h"
#include "llvm/Support/Path.h"
using namespace clang::driver;
using namespace clang::driver::toolchains;
using namespace clang::driver::tools;
using namespace clang;
using namespace llvm::opt;
namespace {
static const char *getOutputFileName(Compilation &C, StringRef Base,
const char *Postfix,
const char *Extension) {
const char *OutputFileName;
if (C.getDriver().isSaveTempsEnabled()) {
OutputFileName =
C.getArgs().MakeArgString(Base.str() + Postfix + "." + Extension);
} else {
std::string TmpName =
C.getDriver().GetTemporaryPath(Base.str() + Postfix, Extension);
OutputFileName = C.addTempFile(C.getArgs().MakeArgString(TmpName));
return OutputFileName;
static void addLLCOptArg(const llvm::opt::ArgList &Args,
llvm::opt::ArgStringList &CmdArgs) {
if (Arg *A = Args.getLastArg(options::OPT_O_Group)) {
StringRef OOpt = "0";
if (A->getOption().matches(options::OPT_O4) ||
OOpt = "3";
else if (A->getOption().matches(options::OPT_O0))
OOpt = "0";
else if (A->getOption().matches(options::OPT_O)) {
// Clang and opt support -Os/-Oz; llc only supports -O0, -O1, -O2 and -O3
// so we map -Os/-Oz to -O2.
// Only clang supports -Og, and maps it to -O1.
// We map anything else to -O2.
OOpt = llvm::StringSwitch<const char *>(A->getValue())
.Case("1", "1")
.Case("2", "2")
.Case("3", "3")
.Case("s", "2")
.Case("z", "2")
.Case("g", "1")
CmdArgs.push_back(Args.MakeArgString("-O" + OOpt));
static bool checkSystemForAMDGPU(const ArgList &Args, const AMDGPUToolChain &TC,
std::string &GPUArch) {
if (auto Err = TC.getSystemGPUArch(Args, GPUArch)) {
std::string ErrMsg =
llvm::formatv("{0}", llvm::fmt_consume(std::move(Err)));
TC.getDriver().Diag(diag::err_drv_undetermined_amdgpu_arch) << ErrMsg;
return false;
return true;
} // namespace
const char *AMDGCN::OpenMPLinker::constructLLVMLinkCommand(
const toolchains::AMDGPUOpenMPToolChain &AMDGPUOpenMPTC, Compilation &C,
const JobAction &JA, const InputInfoList &Inputs, const ArgList &Args,
StringRef SubArchName, StringRef OutputFilePrefix) const {
ArgStringList CmdArgs;
for (const auto &II : Inputs)
if (II.isFilename())
bool HasLibm = false;
if (Args.hasArg(options::OPT_l)) {
auto Lm = Args.getAllArgValues(options::OPT_l);
for (auto &Lib : Lm) {
if (Lib == "m") {
HasLibm = true;
if (HasLibm) {
// This is not certain to work. The device libs added here, and passed to
// llvm-link, are missing attributes that they expect to be inserted when
// passed to mlink-builtin-bitcode. The amdgpu backend does not generate
// conservatively correct code when attributes are missing, so this may
// be the root cause of miscompilations. Passing via mlink-builtin-bitcode
// ultimately hits CodeGenModule::addDefaultFunctionDefinitionAttributes
// on each function, see D28538 for context.
// Potential workarounds:
// - unconditionally link all of the device libs to every translation
// unit in clang via mlink-builtin-bitcode
// - build a libm bitcode file as part of the DeviceRTL and explictly
// mlink-builtin-bitcode the rocm device libs components at build time
// - drop this llvm-link fork in favour or some calls into LLVM, chosen
// to do basically the same work as llvm-link but with that call first
// - write an opt pass that sets that on every function it sees and pipe
// the device-libs bitcode through that on the way to this llvm-link
SmallVector<std::string, 12> BCLibs =
AMDGPUOpenMPTC.getCommonDeviceLibNames(Args, SubArchName.str());
for (StringRef BCFile : BCLibs)
AddStaticDeviceLibsLinking(C, *this, JA, Inputs, Args, CmdArgs, "amdgcn",
SubArchName, /*isBitCodeSDL=*/true,
// Add an intermediate output file.
const char *OutputFileName =
getOutputFileName(C, OutputFilePrefix, "-linked", "bc");
const char *Exec =
JA, *this, ResponseFileSupport::AtFileCurCP(), Exec, CmdArgs, Inputs,
InputInfo(&JA, Args.MakeArgString(OutputFileName))));
// If we linked in libm definitions late we run another round of optimizations
// to inline the definitions and fold what is foldable.
if (HasLibm) {
ArgStringList OptCmdArgs;
const char *OptOutputFileName =
getOutputFileName(C, OutputFilePrefix, "-linked-opt", "bc");
addLLCOptArg(Args, OptCmdArgs);
const char *OptExec =
JA, *this, ResponseFileSupport::AtFileCurCP(), OptExec, OptCmdArgs,
InputInfo(&JA, Args.MakeArgString(OutputFileName)),
InputInfo(&JA, Args.MakeArgString(OptOutputFileName))));
OutputFileName = OptOutputFileName;
return OutputFileName;
const char *AMDGCN::OpenMPLinker::constructLlcCommand(
Compilation &C, const JobAction &JA, const InputInfoList &Inputs,
const llvm::opt::ArgList &Args, llvm::StringRef SubArchName,
llvm::StringRef OutputFilePrefix, const char *InputFileName,
bool OutputIsAsm) const {
// Construct llc command.
ArgStringList LlcArgs;
// The input to llc is the output from opt.
// Pass optimization arg to llc.
addLLCOptArg(Args, LlcArgs);
LlcArgs.push_back(Args.MakeArgString("-mcpu=" + SubArchName));
Args.MakeArgString(Twine("-filetype=") + (OutputIsAsm ? "asm" : "obj")));
for (const Arg *A : Args.filtered(options::OPT_mllvm)) {
// Add output filename
const char *LlcOutputFile =
getOutputFileName(C, OutputFilePrefix, "", OutputIsAsm ? "s" : "o");
const char *Llc = Args.MakeArgString(getToolChain().GetProgramPath("llc"));
JA, *this, ResponseFileSupport::AtFileCurCP(), Llc, LlcArgs, Inputs,
InputInfo(&JA, Args.MakeArgString(LlcOutputFile))));
return LlcOutputFile;
void AMDGCN::OpenMPLinker::constructLldCommand(
Compilation &C, const JobAction &JA, const InputInfoList &Inputs,
const InputInfo &Output, const llvm::opt::ArgList &Args,
const char *InputFileName) const {
// Construct lld command.
// The output from ld.lld is an HSA code object file.
ArgStringList LldArgs{"-flavor", "gnu", "--no-undefined",
"-shared", "-o", Output.getFilename(),
const char *Lld = Args.MakeArgString(getToolChain().GetProgramPath("lld"));
JA, *this, ResponseFileSupport::AtFileCurCP(), Lld, LldArgs, Inputs,
InputInfo(&JA, Args.MakeArgString(Output.getFilename()))));
// For amdgcn the inputs of the linker job are device bitcode and output is
// object file. It calls llvm-link, opt, llc, then lld steps.
void AMDGCN::OpenMPLinker::ConstructJob(Compilation &C, const JobAction &JA,
const InputInfo &Output,
const InputInfoList &Inputs,
const ArgList &Args,
const char *LinkingOutput) const {
const ToolChain &TC = getToolChain();
assert(getToolChain().getTriple().isAMDGCN() && "Unsupported target");
const toolchains::AMDGPUOpenMPToolChain &AMDGPUOpenMPTC =
static_cast<const toolchains::AMDGPUOpenMPToolChain &>(TC);
std::string GPUArch = Args.getLastArgValue(options::OPT_march_EQ).str();
if (GPUArch.empty()) {
if (!checkSystemForAMDGPU(Args, AMDGPUOpenMPTC, GPUArch))
// Prefix for temporary file name.
std::string Prefix;
for (const auto &II : Inputs)
if (II.isFilename())
Prefix = llvm::sys::path::stem(II.getFilename()).str() + "-" + GPUArch;
assert(Prefix.length() && "no linker inputs are files ");
// Each command outputs different files.
const char *LLVMLinkCommand = constructLLVMLinkCommand(
AMDGPUOpenMPTC, C, JA, Inputs, Args, GPUArch, Prefix);
// Produce readable assembly if save-temps is enabled.
if (C.getDriver().isSaveTempsEnabled())
constructLlcCommand(C, JA, Inputs, Args, GPUArch, Prefix, LLVMLinkCommand,
const char *LlcCommand = constructLlcCommand(C, JA, Inputs, Args, GPUArch,
Prefix, LLVMLinkCommand);
constructLldCommand(C, JA, Inputs, Output, Args, LlcCommand);
AMDGPUOpenMPToolChain::AMDGPUOpenMPToolChain(const Driver &D,
const llvm::Triple &Triple,
const ToolChain &HostTC,
const ArgList &Args)
: ROCMToolChain(D, Triple, Args), HostTC(HostTC) {
// Lookup binaries into the driver directory, this is used to
// discover the clang-offload-bundler executable.
void AMDGPUOpenMPToolChain::addClangTargetOptions(
const llvm::opt::ArgList &DriverArgs, llvm::opt::ArgStringList &CC1Args,
Action::OffloadKind DeviceOffloadingKind) const {
HostTC.addClangTargetOptions(DriverArgs, CC1Args, DeviceOffloadingKind);
std::string GPUArch = DriverArgs.getLastArgValue(options::OPT_march_EQ).str();
if (GPUArch.empty()) {
if (!checkSystemForAMDGPU(DriverArgs, *this, GPUArch))
assert(DeviceOffloadingKind == Action::OFK_OpenMP &&
"Only OpenMP offloading kinds are supported.");
if (DriverArgs.hasArg(options::OPT_nogpulib))
// Link the bitcode library late if we're using device LTO.
if (getDriver().isUsingLTO(/* IsOffload */ true))
addOpenMPDeviceRTL(getDriver(), DriverArgs, CC1Args, GPUArch, getTriple());
llvm::opt::DerivedArgList *AMDGPUOpenMPToolChain::TranslateArgs(
const llvm::opt::DerivedArgList &Args, StringRef BoundArch,
Action::OffloadKind DeviceOffloadKind) const {
DerivedArgList *DAL =
HostTC.TranslateArgs(Args, BoundArch, DeviceOffloadKind);
if (!DAL)
DAL = new DerivedArgList(Args.getBaseArgs());
const OptTable &Opts = getDriver().getOpts();
if (DeviceOffloadKind == Action::OFK_OpenMP) {
for (Arg *A : Args)
if (!llvm::is_contained(*DAL, A))
if (!DAL->hasArg(options::OPT_march_EQ)) {
std::string Arch = BoundArch.str();
if (BoundArch.empty())
checkSystemForAMDGPU(Args, *this, Arch);
DAL->AddJoinedArg(nullptr, Opts.getOption(options::OPT_march_EQ), Arch);
return DAL;
for (Arg *A : Args) {
if (!BoundArch.empty()) {
DAL->AddJoinedArg(nullptr, Opts.getOption(options::OPT_march_EQ),
return DAL;
Tool *AMDGPUOpenMPToolChain::buildLinker() const {
return new tools::AMDGCN::OpenMPLinker(*this);
void AMDGPUOpenMPToolChain::addClangWarningOptions(
ArgStringList &CC1Args) const {
AMDGPUOpenMPToolChain::GetCXXStdlibType(const ArgList &Args) const {
return HostTC.GetCXXStdlibType(Args);
void AMDGPUOpenMPToolChain::AddClangSystemIncludeArgs(
const ArgList &DriverArgs, ArgStringList &CC1Args) const {
HostTC.AddClangSystemIncludeArgs(DriverArgs, CC1Args);
void AMDGPUOpenMPToolChain::AddIAMCUIncludeArgs(const ArgList &Args,
ArgStringList &CC1Args) const {
HostTC.AddIAMCUIncludeArgs(Args, CC1Args);
SanitizerMask AMDGPUOpenMPToolChain::getSupportedSanitizers() const {
// The AMDGPUOpenMPToolChain only supports sanitizers in the sense that it
// allows sanitizer arguments on the command line if they are supported by the
// host toolchain. The AMDGPUOpenMPToolChain will actually ignore any command
// line arguments for any of these "supported" sanitizers. That means that no
// sanitization of device code is actually supported at this time.
// This behavior is necessary because the host and device toolchains
// invocations often share the command line, so the device toolchain must
// tolerate flags meant only for the host toolchain.
return HostTC.getSupportedSanitizers();
AMDGPUOpenMPToolChain::computeMSVCVersion(const Driver *D,
const ArgList &Args) const {
return HostTC.computeMSVCVersion(D, Args);