[OpenMP] Add flag for overwriting default PTX version for OpenMP targets

Summary:
This flag "--fopenmp-ptx=" enables the overwriting of the default PTX version used for GPU offloaded OpenMP target regions: "+ptx42".



Reviewers: arpith-jacob, caomhin, carlo.bertolli, ABataev, Hahnfeld, jlebar, hfinkel, tstellar

Reviewed By: ABataev

Subscribers: rengolin, cfe-commits

Differential Revision: https://reviews.llvm.org/D29660

llvm-svn: 310489

3 files changed, 21 insertions, 3 deletions

diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index c86941181b7..a303143850e 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -544,6 +544,8 @@ 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 fopenmp_ptx_EQ : Joined<["--"], "fopenmp-ptx=">, Flags<[DriverOption]>,
+  HelpText<"Pass a PTX version +ptxXX, default +ptx42 (for PTX version 4.2) used by OpenMP device offloading.">;
 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">,
diff --git a/clang/lib/Driver/ToolChains/Cuda.cpp b/clang/lib/Driver/ToolChains/Cuda.cpp
index 1ff41ce66d4..b6a7b829f50 100644
--- a/clang/lib/Driver/ToolChains/Cuda.cpp
+++ b/clang/lib/Driver/ToolChains/Cuda.cpp
@@ -481,7 +481,13 @@ void CudaToolChain::addClangTargetOptions(
   // than LLVM defaults to. Use PTX4.2 which is the PTX version that
   // came with CUDA-7.0.
   CC1Args.push_back("-target-feature");
-  CC1Args.push_back("+ptx42");
+
+  if (DeviceOffloadingKind == Action::OFK_OpenMP)
+    CC1Args.push_back(
+        DriverArgs.getLastArgValue(options::OPT_fopenmp_ptx_EQ,
+                                   "+ptx42").data());
+  else
+    CC1Args.push_back("+ptx42");
 }
 
 void CudaToolChain::AddCudaIncludeArgs(const ArgList &DriverArgs,
diff --git a/clang/test/Driver/openmp-offload.c b/clang/test/Driver/openmp-offload.c
index cd2ca3e3d6e..30dd1ea2ab0 100644
--- a/clang/test/Driver/openmp-offload.c
+++ b/clang/test/Driver/openmp-offload.c
@@ -699,7 +699,7 @@
 /// ###########################################################################
 
 /// PTXAS is passed -c flag by default when offloading to an NVIDIA device using OpenMP - disable it.
-// RUN:   %clang -### -fopenmp=libomp -fopenmp-targets=nvptx64-nvidia-cuda -fnoopenmp-relocatable-target -save-temps -no-canonical-prefixes %s 2>&1 \
+// RUN:   %clang -### -fopenmp=libomp -fopenmp-targets=nvptx64-nvidia-cuda -fnoopenmp-relocatable-target -no-canonical-prefixes %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=CHK-PTXAS-NORELO %s
 
 // CHK-PTXAS-NORELO-NOT: ptxas{{.*}}" "-c"
@@ -708,7 +708,17 @@
 
 /// PTXAS is passed -c flag by default when offloading to an NVIDIA device using OpenMP
 /// Check that the flag is passed when -fopenmp-relocatable-target is used.
-// RUN:   %clang -### -fopenmp=libomp -fopenmp-targets=nvptx64-nvidia-cuda -fopenmp-relocatable-target -save-temps -no-canonical-prefixes %s 2>&1 \
+// RUN:   %clang -### -fopenmp=libomp -fopenmp-targets=nvptx64-nvidia-cuda -fopenmp-relocatable-target -no-canonical-prefixes %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=CHK-PTXAS-RELO %s
 
 // CHK-PTXAS-RELO: ptxas{{.*}}" "-c"
+
+/// ###########################################################################
+
+/// Check PTXAS is passed the compute capability passed to the driver.
+// RUN:   %clang -### -fopenmp=libomp -fopenmp-targets=nvptx64-nvidia-cuda --fopenmp-ptx=+ptx52 -save-temps -no-canonical-prefixes %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHK-PTXAS-VERSION %s
+
+// CHK-PTXAS-VERSION: clang{{.*}}.bc" {{.*}}"-target-feature" "+ptx52"
+// CHK-PTXAS-VERSION-NEXT: clang{{.*}}.bc" {{.*}}"-target-feature" "+ptx52"
+// CHK-PTXAS-VERSION-NEXT: clang{{.*}}.bc" {{.*}}"-target-feature" "+ptx52"