[PATCH] D117246: [OpenMP] Add support for linking AMDGPU images

[Joseph Huber via Phabricator via cfe-commits]

jhuber6 created this revision.
jhuber6 added reviewers: jdoerfert, gregrodgers, JonChesterfield, ronlieb.
Herald added subscribers: kerbowa, guansong, t-tye, tpr, dstuttard, yaxunl, 
nhaehnle, jvesely, kzhuravl.
jhuber6 requested review of this revision.
Herald added subscribers: cfe-commits, sstefan1, wdng.
Herald added a project: clang.

This patch adds support for linking AMDGPU images using the LLD binary.
AMDGPU files are always bitcode images and will always use the LTO
backend. Additionally we now pass the default architecture found with
the `amdgpu-arch` tool to the argument list.

Depends on D117156 <https://reviews.llvm.org/D117156>


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D117246

Files:
  clang/lib/Driver/ToolChains/AMDGPUOpenMP.cpp
  clang/tools/clang-linker-wrapper/ClangLinkerWrapper.cpp


Index: clang/tools/clang-linker-wrapper/ClangLinkerWrapper.cpp
===================================================================
--- clang/tools/clang-linker-wrapper/ClangLinkerWrapper.cpp
+++ clang/tools/clang-linker-wrapper/ClangLinkerWrapper.cpp
@@ -512,7 +512,7 @@
   // Create a new file to write the linked device image to.
   SmallString<128> TempFile;
   if (std::error_code EC = sys::fs::createTemporaryFile(
-          TheTriple.getArchName() + "-" + Arch, "cubin", TempFile))
+          "lto-" + TheTriple.getArchName() + "-" + Arch, "cubin", TempFile))
     return createFileError(TempFile, EC);
   TempFiles.push_back(static_cast<std::string>(TempFile));
 
@@ -590,6 +590,50 @@
   return static_cast<std::string>(TempFile);
 }
 } // namespace nvptx
+namespace amdgcn {
+Expected<std::string> link(ArrayRef<std::string> InputFiles,
+                           ArrayRef<std::string> LinkerArgs, Triple TheTriple,
+                           StringRef Arch) {
+  // AMDGPU uses the lld binary to link device object files.
+  ErrorOr<std::string> LLDPath =
+      sys::findProgramByName("lld", sys::path::parent_path(LinkerExecutable));
+  if (!LLDPath)
+    LLDPath = sys::findProgramByName("lld");
+  if (!LLDPath)
+    return createStringError(LLDPath.getError(),
+                             "Unable to find 'lld' in path");
+
+  // Create a new file to write the linked device image to.
+  SmallString<128> TempFile;
+  if (std::error_code EC = sys::fs::createTemporaryFile(
+          TheTriple.getArchName() + "-" + Arch + "-image", "out", TempFile))
+    return createFileError(TempFile, EC);
+  TempFiles.push_back(static_cast<std::string>(TempFile));
+
+  SmallVector<StringRef, 16> CmdArgs;
+  CmdArgs.push_back(*LLDPath);
+  CmdArgs.push_back("-flavor");
+  CmdArgs.push_back("gnu");
+  CmdArgs.push_back("--no-undefined");
+  CmdArgs.push_back("-shared");
+  CmdArgs.push_back("-o");
+  CmdArgs.push_back(TempFile);
+
+  // Copy system library paths used by the host linker.
+  for (StringRef Arg : LinkerArgs)
+    if (Arg.startswith("-L"))
+      CmdArgs.push_back(Arg);
+
+  // Add extracted input files.
+  for (StringRef Input : InputFiles)
+    CmdArgs.push_back(Input);
+
+  if (sys::ExecuteAndWait(*LLDPath, CmdArgs))
+    return createStringError(inconvertibleErrorCode(), "'lld' failed");
+
+  return static_cast<std::string>(TempFile);
+}
+} // namespace amdgcn
 
 Expected<std::string> linkDevice(ArrayRef<std::string> InputFiles,
                                  ArrayRef<std::string> LinkerArgs,
@@ -599,7 +643,7 @@
   case Triple::nvptx64:
     return nvptx::link(InputFiles, LinkerArgs, TheTriple, Arch);
   case Triple::amdgcn:
-    // TODO: AMDGCN linking support.
+    return amdgcn::link(InputFiles, LinkerArgs, TheTriple, Arch);
   case Triple::x86:
   case Triple::x86_64:
     // TODO: x86 linking support.
Index: clang/lib/Driver/ToolChains/AMDGPUOpenMP.cpp
===================================================================
--- clang/lib/Driver/ToolChains/AMDGPUOpenMP.cpp
+++ clang/lib/Driver/ToolChains/AMDGPUOpenMP.cpp
@@ -289,10 +289,22 @@
 
   const OptTable &Opts = getDriver().getOpts();
 
-  if (DeviceOffloadKind != Action::OFK_OpenMP) {
-    for (Arg *A : Args) {
-      DAL->append(A);
+  if (DeviceOffloadKind == Action::OFK_OpenMP) {
+    for (Arg *A : Args)
+      if (!llvm::is_contained(*DAL, A))
+        DAL->append(A);
+
+    std::string Arch = DAL->getLastArgValue(options::OPT_march_EQ).str();
+    if (Arch.empty()) {
+      checkSystemForAMDGPU(Args, *this, Arch);
+      DAL->AddJoinedArg(nullptr, Opts.getOption(options::OPT_march_EQ), Arch);
     }
+
+    return DAL;
+  }
+
+  for (Arg *A : Args) {
+    DAL->append(A);
   }
 
   if (!BoundArch.empty()) {

_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits