[PATCH] D89752: [CUDA] Improve clang's ability to detect recent CUDA versions.

[Artem Belevich via Phabricator via cfe-commits]

tra created this revision.
tra added reviewers: yaxunl, emankov, hans.
Herald added a subscriber: bixia.
Herald added a project: clang.
tra requested review of this revision.

CUDA-11.1 does not carry version.txt which causes clang to assume that it's
CUDA-7.0, which used to be the only CUDA version w/o version.txt.

In order to tell CUDA-7.0 apart from the new versions, clang now probes for the
presence of libdevice.10.bc which is not present in the old CUDA versions.

This should keep Clang working for CUDA-11.1.

Bug: https://bugs.llvm.org/show_bug.cgi?id=47332


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D89752

Files:
  clang/lib/Driver/ToolChains/Cuda.cpp


Index: clang/lib/Driver/ToolChains/Cuda.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Cuda.cpp
+++ clang/lib/Driver/ToolChains/Cuda.cpp
@@ -155,9 +155,14 @@
     llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> VersionFile =
         FS.getBufferForFile(InstallPath + "/version.txt");
     if (!VersionFile) {
-      // CUDA 7.0 doesn't have a version.txt, so guess that's our version if
-      // version.txt isn't present.
-      Version = CudaVersion::CUDA_70;
+      // CUDA 7.0 and CUDA 11.1+ do not have version.txt file.
+      // Use libdevice file to distinguish 7.0 from the new versions.
+      if (FS.exists(LibDevicePath + "/libdevice.10.bc")) {
+        Version = CudaVersion::LATEST;
+        DetectedVersionIsNotSupported = Version > CudaVersion::LATEST_SUPPORTED;
+      } else {
+        Version = CudaVersion::CUDA_70;
+      }
     } else {
       ParseCudaVersionFile((*VersionFile)->getBuffer());
     }


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