HIPSPV.cpp

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//===--- HIPSPV.cpp - HIPSPV ToolChain Implementation -----------*- 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
//
//===----------------------------------------------------------------------===//
 
#include "HIPSPV.h"
#include "HIPUtility.h"
#include "clang/Driver/CommonArgs.h"
#include "clang/Driver/Compilation.h"
#include "clang/Driver/Driver.h"
#include "clang/Driver/InputInfo.h"
#include "clang/Options/Options.h"
#include "llvm/MC/TargetRegistry.h"
#include "llvm/Support/FileSystem.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;
 
// Locates HIP pass plugin.
static std::string findPassPlugin(const Driver &D,
                                  const llvm::opt::ArgList &Args) {
  StringRef Path = Args.getLastArgValue(options::OPT_hipspv_pass_plugin_EQ);
  if (!Path.empty()) {
    if (llvm::sys::fs::exists(Path))
      return Path.str();
    D.Diag(diag::err_drv_no_such_file) << Path;
  }
 
  StringRef hipPath = Args.getLastArgValue(options::OPT_hip_path_EQ);
  if (!hipPath.empty()) {
    SmallString<128> PluginPath(hipPath);
    llvm::sys::path::append(PluginPath, "lib", "libLLVMHipSpvPasses.so");
    if (llvm::sys::fs::exists(PluginPath))
      return PluginPath.str().str();
    PluginPath.assign(hipPath);
    llvm::sys::path::append(PluginPath, "lib", "llvm",
                            "libLLVMHipSpvPasses.so");
    if (llvm::sys::fs::exists(PluginPath))
      return PluginPath.str().str();
  }
 
  return std::string();
}
 
// Is the in-tree SPIR-V backend built into this clang?
static bool isSPIRVBackendAvailable(const llvm::Triple &T) {
  std::string IgnoredError;
  return llvm::TargetRegistry::lookupTarget(T, IgnoredError);
}
 
// Runs the HipSpvPasses plugin via `opt` on TempFile when the plugin is found.
// Returns the lowered bitcode path, or TempFile unchanged if no plugin exists.
static const char *runHipSpvPasses(Compilation &C, const JobAction &JA,
                                   const Tool &Creator, const ToolChain &TC,
                                   const InputInfoList &Inputs,
                                   const InputInfo &Output,
                                   const llvm::opt::ArgList &Args,
                                   StringRef Name, const char *TempFile) {
  auto PassPluginPath = findPassPlugin(C.getDriver(), Args);
  if (PassPluginPath.empty())
    return TempFile;
  const char *PassPathCStr = C.getArgs().MakeArgString(PassPluginPath);
  const char *OptOutput = HIP::getTempFile(C, Name.str() + "-lower", "bc");
  ArgStringList OptArgs{TempFile,     "-load-pass-plugin",
                        PassPathCStr, "-passes=hip-post-link-passes",
                        "-o",         OptOutput};
  const char *Opt = Args.MakeArgString(TC.GetProgramPath("opt"));
  C.addCommand(std::make_unique<Command>(
      JA, Creator, ResponseFileSupport::None(), Opt, OptArgs, Inputs, Output));
  return OptOutput;
}
 
void HIPSPV::Linker::constructLinkAndEmitSpirvCommand(
    Compilation &C, const JobAction &JA, const InputInfoList &Inputs,
    const InputInfo &Output, const llvm::opt::ArgList &Args) const {
 
  assert(!Inputs.empty() && "Must have at least one input.");
  std::string Name = std::string(llvm::sys::path::stem(Output.getFilename()));
  const char *TempFile = HIP::getTempFile(C, Name + "-link", "bc");
 
  // Link LLVM bitcode.
  ArgStringList LinkArgs{};
 
  for (auto Input : Inputs)
    if (Input.isFilename())
      LinkArgs.push_back(Input.getFilename());
 
  tools::constructLLVMLinkCommand(C, *this, JA, Inputs, LinkArgs, Output, Args,
                                  TempFile);
 
  auto T = getToolChain().getTriple();
 
  if (T.getOS() == llvm::Triple::ChipStar) {
    // chipStar: run HipSpvPasses via opt, then emit SPIR-V with the in-tree
    // SPIR-V backend by default, or with the external llvm-spirv translator
    // when -fno-integrated-objemitter is given (or the backend is not built).
 
    // Run HipSpvPasses plugin via opt (must run on LLVM IR before
    // the SPIR-V backend lowers to MIR).
    TempFile = runHipSpvPasses(C, JA, *this, getToolChain(), Inputs, Output,
                               Args, Name, TempFile);
 
    // Note that useIntegratedBackend() is consulted first so that an explicit
    // -f(no-)integrated-objemitter still gets diagnosed against this toolchain.
    if (!getToolChain().useIntegratedBackend() || !isSPIRVBackendAvailable(T)) {
      // External translator path: BC -> SPIR-V via llvm-spirv.
      llvm::opt::ArgStringList TrArgs;
      if (T.getSubArch() == llvm::Triple::NoSubArch)
        TrArgs.push_back("--spirv-max-version=1.2");
      // Keep this extension list in sync with the in-tree backend fallback
      // below.
      TrArgs.push_back("--spirv-ext=-all"
                       ",+SPV_INTEL_function_pointers"
                       ",+SPV_INTEL_subgroups"
                       ",+SPV_KHR_bit_instructions"
                       ",+SPV_EXT_shader_atomic_float_add");
 
      // Preserve debug info in the NonSemantic.Shader.DebugInfo form (see the
      // comment on the equivalent block in the non-chipStar path below).
      // These flags are passed unconditionally instead of gating on -g: in
      // RDC-mode links this job runs in a clang invoked by
      // clang-linker-wrapper where the original -g is not visible, but the
      // debug info itself travels in the bitcode. SPV_KHR_non_semantic_info
      // and the debug info version only take effect when the bitcode carries
      // debug info. SPV_INTEL_optnone is not tied to debug info: clang emits
      // optnone at -O0 even without -g, and the emitter needs the extension
      // allowed to encode it.
      TrArgs.push_back("--spirv-ext=+SPV_KHR_non_semantic_info"
                       ",+SPV_INTEL_optnone");
      TrArgs.push_back("--spirv-debug-info-version=nonsemantic-shader-200");
 
      InputInfo TrInput = InputInfo(types::TY_LLVM_BC, TempFile, "");
      SPIRV::constructTranslateCommand(C, *this, JA, Output, TrInput, TrArgs);
      return;
    }
 
    // Default: compile the lowered bitcode to SPIR-V with the in-tree backend.
    // Invoke `clang -cc1` directly rather than the clang driver: the driver
    // would re-run config-file loading, toolchain detection and argument
    // translation over an input that is already device-compiled and lowered,
    // which is both wasteful and fragile. This mirrors how HIPAMD drives its
    // SPIR-V backend emission (see HIPAMD::constructLinkAndEmitSpirvCommand).
    // Keep the default -O0 backend pipeline (i.e. no -disable-llvm-optzns) so
    // the mandatory lowering passes still run, matching the previously
    // validated driver `-c` behavior.
    ArgStringList Cc1Args;
    Cc1Args.push_back("-cc1");
    Cc1Args.push_back("-triple");
    Cc1Args.push_back(C.getArgs().MakeArgString(T.getTriple()));
    Cc1Args.push_back("-emit-obj");
 
    // SPIR-V extensions the chipStar runtime relies on. Keep in sync with the
    // llvm-spirv translator path above. SPV_KHR_non_semantic_info and
    // SPV_INTEL_optnone let the backend emit NonSemantic.Shader.DebugInfo and
    // the OptNoneINTEL function control when the bitcode carries debug info /
    // optnone attributes (the backend's debug handler is a no-op otherwise).
    Cc1Args.push_back("-mllvm");
    Cc1Args.push_back("-spirv-ext=+SPV_INTEL_function_pointers"
                      ",+SPV_INTEL_subgroups"
                      ",+SPV_KHR_bit_instructions"
                      ",+SPV_EXT_shader_atomic_float_add"
                      ",+SPV_KHR_non_semantic_info"
                      ",+SPV_INTEL_optnone");
 
    Cc1Args.push_back(TempFile);
    Cc1Args.push_back("-o");
    Cc1Args.push_back(Output.getFilename());
 
    const Driver &Drv = C.getDriver();
    const char *Clang = Drv.getDriverProgramPath();
    C.addCommand(std::make_unique<Command>(
        JA, *this, ResponseFileSupport::None(), Clang, Cc1Args, Inputs, Output,
        Drv.getPrependArg()));
    return;
  }
 
  // Non-chipStar: run HIP passes via opt, then translate with llvm-spirv.
  TempFile = runHipSpvPasses(C, JA, *this, getToolChain(), Inputs, Output, Args,
                             Name, TempFile);
 
  // Emit SPIR-V binary via llvm-spirv translator (non-chipStar targets).
  llvm::opt::ArgStringList TrArgs;
  if (T.getSubArch() == llvm::Triple::NoSubArch)
    TrArgs.push_back("--spirv-max-version=1.1");
  TrArgs.push_back("--spirv-ext=+all");
 
  // Preserve debug info requested via -g into the emitted SPIR-V using the
  // NonSemantic.Shader.DebugInfo form. Downstream consumers such as Intel's IGC
  // and gdb-oneapi use it to map device code back to source lines and local
  // variables; the translator's default OpenCL.DebugInfo.100 form is not
  // sufficient for that. Emitting the NonSemantic debug instructions requires
  // the SPV_KHR_non_semantic_info extension.
  //
  // SPV_INTEL_optnone carries the optnone function attribute, which Clang
  // attaches to every function at -O0, through to the consumer as the
  // OptNoneEXT function control. Without it the attribute is silently dropped
  // in translation and the device compiler is free to optimize the kernel, so a
  // debugger reports arguments and locals as <optimized out> even though the
  // debug info itself is present. At -O1 and above no optnone attribute exists
  // and the extension has no effect. It is redundant for the +all list above
  // but required for the restricted chipStar one.
  //
  // The translator accumulates --spirv-ext across occurrences, so this augments
  // the list set above.
  if (const Arg *A = Args.getLastArg(options::OPT_g_Group);
      A && !A->getOption().matches(options::OPT_g0)) {
    TrArgs.push_back("--spirv-ext=+SPV_KHR_non_semantic_info"
                     ",+SPV_INTEL_optnone");
    TrArgs.push_back("--spirv-debug-info-version=nonsemantic-shader-200");
  }
 
  InputInfo TrInput = InputInfo(types::TY_LLVM_BC, TempFile, "");
  SPIRV::constructTranslateCommand(C, *this, JA, Output, TrInput, TrArgs);
}
 
void HIPSPV::Linker::ConstructJob(Compilation &C, const JobAction &JA,
                                  const InputInfo &Output,
                                  const InputInfoList &Inputs,
                                  const ArgList &Args,
                                  const char *LinkingOutput) const {
  if (JA.getType() == types::TY_HIP_FATBIN)
    return HIP::constructHIPFatbinCommand(C, JA, Output.getFilename(), Inputs,
                                          Args, *this);
 
  constructLinkAndEmitSpirvCommand(C, JA, Inputs, Output, Args);
}
 
HIPSPVToolChain::HIPSPVToolChain(const Driver &D, const llvm::Triple &Triple,
                                 const ToolChain &HostTC, const ArgList &Args)
    : ToolChain(D, Triple, Args), HostTC(&HostTC) {
  // Lookup binaries into the driver directory, this is used to
  // discover the clang-offload-bundler executable.
  getProgramPaths().push_back(getDriver().Dir);
}
 
// Non-offloading toolchain. Primaly used by clang-offload-linker.
HIPSPVToolChain::HIPSPVToolChain(const Driver &D, const llvm::Triple &Triple,
                                 const ArgList &Args)
    : ToolChain(D, Triple, Args), HostTC(nullptr) {
  // Lookup binaries into the driver directory, this is used to
  // discover the clang-offload-bundler executable.
  getProgramPaths().push_back(getDriver().Dir);
}
 
bool HIPSPVToolChain::IsIntegratedBackendSupported() const {
  // The in-tree SPIR-V backend can only be requested when it is built.
  return isSPIRVBackendAvailable(getTriple());
}
 
void HIPSPVToolChain::addClangTargetOptions(
    const llvm::opt::ArgList &DriverArgs, llvm::opt::ArgStringList &CC1Args,
    BoundArch BA, Action::OffloadKind DeviceOffloadingKind) const {
 
  if (!HostTC) {
    assert(DeviceOffloadingKind == Action::OFK_None &&
           "Need host toolchain for offloading!");
    return;
  }
 
  HostTC->addClangTargetOptions(DriverArgs, CC1Args, BA, DeviceOffloadingKind);
 
  assert(DeviceOffloadingKind == Action::OFK_HIP &&
         "Only HIP offloading kinds are supported for GPUs.");
 
  CC1Args.append(
      {"-fcuda-is-device",
       // A crude workaround for llvm-spirv which does not handle the
       // autovectorized code well (vector reductions, non-i{8,16,32,64} types).
       // TODO: Allow autovectorization when SPIR-V backend arrives.
       "-mllvm", "-vectorize-loops=false", "-mllvm", "-vectorize-slp=false"});
 
  // Default to "hidden" visibility, as object level linking will not be
  // supported for the foreseeable future.
  if (!DriverArgs.hasArg(options::OPT_fvisibility_EQ,
                         options::OPT_fvisibility_ms_compat))
    CC1Args.append(
        {"-fvisibility=hidden", "-fapply-global-visibility-to-externs"});
 
  for (const BitCodeLibraryInfo &BCFile :
       getDeviceLibs(DriverArgs, BA, DeviceOffloadingKind))
    CC1Args.append(
        {"-mlink-builtin-bitcode", DriverArgs.MakeArgString(BCFile.Path)});
}
 
Tool *HIPSPVToolChain::buildLinker() const {
  assert(getTriple().getArch() == llvm::Triple::spirv64);
  return new tools::HIPSPV::Linker(*this);
}
 
void HIPSPVToolChain::addClangWarningOptions(ArgStringList &CC1Args) const {
  if (HostTC)
    HostTC->addClangWarningOptions(CC1Args);
  ToolChain::addClangWarningOptions(CC1Args);
}
 
ToolChain::CXXStdlibType
HIPSPVToolChain::GetCXXStdlibType(const ArgList &Args) const {
  if (HostTC)
    return HostTC->GetCXXStdlibType(Args);
  return ToolChain::GetCXXStdlibType(Args);
}
 
void HIPSPVToolChain::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
                                                ArgStringList &CC1Args) const {
  if (HostTC)
    HostTC->AddClangSystemIncludeArgs(DriverArgs, CC1Args);
  ToolChain::AddClangSystemIncludeArgs(DriverArgs, CC1Args);
}
 
void HIPSPVToolChain::AddClangCXXStdlibIncludeArgs(
    const ArgList &Args, ArgStringList &CC1Args) const {
  if (HostTC)
    HostTC->AddClangCXXStdlibIncludeArgs(Args, CC1Args);
  ToolChain::AddClangCXXStdlibIncludeArgs(Args, CC1Args);
}
 
void HIPSPVToolChain::AddIAMCUIncludeArgs(const ArgList &Args,
                                          ArgStringList &CC1Args) const {
  if (HostTC)
    HostTC->AddIAMCUIncludeArgs(Args, CC1Args);
  ToolChain::AddIAMCUIncludeArgs(Args, CC1Args);
}
 
void HIPSPVToolChain::AddHIPIncludeArgs(const ArgList &DriverArgs,
                                        ArgStringList &CC1Args) const {
  if (!DriverArgs.hasFlag(options::OPT_offload_inc, options::OPT_no_offload_inc,
                          true))
    return;
 
  StringRef hipPath = DriverArgs.getLastArgValue(options::OPT_hip_path_EQ);
  if (hipPath.empty()) {
    getDriver().Diag(diag::err_drv_hipspv_no_hip_path);
    return;
  }
  SmallString<128> P(hipPath);
  llvm::sys::path::append(P, "include");
  CC1Args.append({"-isystem", DriverArgs.MakeArgString(P)});
}
 
llvm::SmallVector<ToolChain::BitCodeLibraryInfo, 12>
HIPSPVToolChain::getDeviceLibs(
    const llvm::opt::ArgList &DriverArgs, BoundArch BA,
    const Action::OffloadKind DeviceOffloadingKind) const {
  llvm::SmallVector<ToolChain::BitCodeLibraryInfo, 12> BCLibs;
  if (!DriverArgs.hasFlag(options::OPT_offloadlib, options::OPT_no_offloadlib,
                          true))
    return {};
 
  ArgStringList LibraryPaths;
  // Find device libraries in --hip-device-lib-path and HIP_DEVICE_LIB_PATH.
  auto HipDeviceLibPathArgs = DriverArgs.getAllArgValues(
      // --hip-device-lib-path is alias to this option.
      options::OPT_rocm_device_lib_path_EQ);
  for (auto Path : HipDeviceLibPathArgs)
    LibraryPaths.push_back(DriverArgs.MakeArgString(Path));
 
  StringRef HipPath = DriverArgs.getLastArgValue(options::OPT_hip_path_EQ);
  if (!HipPath.empty()) {
    SmallString<128> Path(HipPath);
    llvm::sys::path::append(Path, "lib", "hip-device-lib");
    LibraryPaths.push_back(DriverArgs.MakeArgString(Path));
  }
 
  addDirectoryList(DriverArgs, LibraryPaths, "", "HIP_DEVICE_LIB_PATH");
 
  // Maintain compatability with --hip-device-lib.
  auto BCLibArgs = DriverArgs.getAllArgValues(options::OPT_hip_device_lib_EQ);
  if (!BCLibArgs.empty()) {
    bool Found = false;
    for (StringRef BCName : BCLibArgs) {
      StringRef FullName;
      for (std::string LibraryPath : LibraryPaths) {
        SmallString<128> Path(LibraryPath);
        llvm::sys::path::append(Path, BCName);
        FullName = Path;
        if (llvm::sys::fs::exists(FullName)) {
          BCLibs.emplace_back(FullName.str());
          Found = true;
          break;
        }
      }
      if (!Found)
        getDriver().Diag(diag::err_drv_no_such_file) << BCName;
    }
  } else {
    // Search device library named as 'hipspv-<triple>.bc'.
    auto TT = getTriple().normalize();
    std::string BCName = "hipspv-" + TT + ".bc";
    for (auto *LibPath : LibraryPaths) {
      SmallString<128> Path(LibPath);
      llvm::sys::path::append(Path, BCName);
      if (llvm::sys::fs::exists(Path)) {
        BCLibs.emplace_back(Path.str().str());
        return BCLibs;
      }
    }
    getDriver().Diag(diag::err_drv_no_hipspv_device_lib)
        << 1 << ("'" + TT + "' target");
    return {};
  }
 
  return BCLibs;
}
 
SanitizerMask HIPSPVToolChain::getSupportedSanitizers(
    BoundArch BA, Action::OffloadKind DeviceOffloadKind) const {
  // The HIPSPVToolChain only supports sanitizers in the sense that it allows
  // sanitizer arguments on the command line if they are supported by the host
  // toolchain. The HIPSPVToolChain 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.
 
  // FIXME: Be accurate and use DeviceOffloadKind.
  if (HostTC)
    return HostTC->getSupportedSanitizers(BA, DeviceOffloadKind);
  return ToolChain::getSupportedSanitizers(BA, DeviceOffloadKind);
}
 
VersionTuple HIPSPVToolChain::computeMSVCVersion(const Driver *D,
                                                 const ArgList &Args) const {
  if (HostTC)
    return HostTC->computeMSVCVersion(D, Args);
  return ToolChain::computeMSVCVersion(D, Args);
}
 
void HIPSPVToolChain::adjustDebugInfoKind(
    llvm::codegenoptions::DebugInfoKind &DebugInfoKind,
    const llvm::opt::ArgList &Args) const {
  // Historically device debug info was force-disabled here because the
  // SPIRV-LLVM-Translator aborted on DW_OP_LLVM_convert debug expressions. The
  // translator now lowers that operation, so honor the debug level the user
  // requested (e.g. via -g) and let it flow into the emitted SPIR-V.
  // constructLinkAndEmitSpirvCommand() enables the NonSemantic.Shader.DebugInfo
  // form at translation time so downstream tools (e.g. gdb-oneapi) can consume
  // it. Leaving DebugInfoKind untouched keeps the default (no -g) behavior,
  // since the driver defaults it to NoDebugInfo.
  (void)DebugInfoKind;
  (void)Args;
}