[CUDA] Add --ptxas-path= flag.

Justin Lebar · Justin Lebar · commit 3cf25461e05d · 2016-12-15T18:44:57.000Z
Summary: This lets you build with one CUDA installation but use ptxas from another install. This is useful e.g. if you want to avoid bugs in an old ptxas without actually upgrading wholesale to a newer CUDA version. Reviewers: tra Subscribers: cfe-commits Differential Revision: https://reviews.llvm.org/D27788 llvm-svn: 289847
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
@@ -425,6 +425,8 @@ def no_cuda_version_check : Flag<["--"], "no-cuda-version-check">,
 def no_cuda_noopt_device_debug : Flag<["--"], "no-cuda-noopt-device-debug">;
 def cuda_path_EQ : Joined<["--"], "cuda-path=">, Group<i_Group>,
   HelpText<"CUDA installation path">;
+def ptxas_path_EQ : Joined<["--"], "ptxas-path=">, Group<i_Group>,
+  HelpText<"Path to ptxas (used for compiling CUDA code)">;
 def fcuda_flush_denormals_to_zero : Flag<["-"], "fcuda-flush-denormals-to-zero">,
   Flags<[CC1Option]>, HelpText<"Flush denormal floating point values to zero in CUDA device mode.">;
 def fno_cuda_flush_denormals_to_zero : Flag<["-"], "fno-cuda-flush-denormals-to-zero">;
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
@@ -12105,7 +12105,11 @@ void NVPTX::Assembler::ConstructJob(Compilation &C, const JobAction &JA,
   for (const auto& A : Args.getAllArgValues(options::OPT_Xcuda_ptxas))
     CmdArgs.push_back(Args.MakeArgString(A));
 
-  const char *Exec = Args.MakeArgString(TC.GetProgramPath("ptxas"));
+  const char *Exec;
+  if (Arg *A = Args.getLastArg(options::OPT_ptxas_path_EQ))
+    Exec = A->getValue();
+  else
+    Exec = Args.MakeArgString(TC.GetProgramPath("ptxas"));
   C.addCommand(llvm::make_unique<Command>(JA, *this, Exec, CmdArgs, Inputs));
 }
 
diff --git a/clang/test/Driver/cuda-ptxas-path.cu b/clang/test/Driver/cuda-ptxas-path.cu
@@ -0,0 +1,12 @@
+// REQUIRES: clang-driver
+// REQUIRES: x86-registered-target
+// REQUIRES: nvptx-registered-target
+
+// RUN: %clang -### --target=i386-unknown-linux \
+// RUN:   --cuda-path=%S/Inputs/CUDA_80/usr/local/cuda \
+// RUN:   --ptxas-path=/some/path/to/ptxas %s 2>&1 \
+// RUN: | FileCheck %s
+
+// CHECK-NOT: "ptxas"
+// CHECK: "/some/path/to/ptxas"
+// CHECK-SAME: "--gpu-name" "sm_20"
