[PATCH] D42452: [CUDA] Disable PGO and coverage instrumentation in NVPTX.

[Artem Belevich via Phabricator via cfe-commits]

tra created this revision.
tra added a reviewer: jlebar.
Herald added a subscriber: sanjoy.

NVPTX does not have runtime support necessary for profiling to work
and even call arc collection is prohibitively expensive. Furthermore,
there's no easy way to collect the samples. NVPTX also does not
support global constructors that clang generates if sample/arc collection
is enabled.


https://reviews.llvm.org/D42452

Files:
  clang/lib/Driver/ToolChains/Clang.cpp
  clang/test/Driver/cuda-no-pgo-or-coverage.cu


Index: clang/test/Driver/cuda-no-pgo-or-coverage.cu
===================================================================
--- /dev/null
+++ clang/test/Driver/cuda-no-pgo-or-coverage.cu
@@ -0,0 +1,34 @@
+// Check that profiling/coverage arguments doen't get passed down to device-side
+// compilation.
+//
+// REQUIRES: clang-driver
+//
+// XRUN: %clang -### -target x86_64-linux-gnu -c --cuda-gpu-arch=sm_20 \
+// XRUN:   -fprofile-generate %s 2>&1 | \
+// XRUN: FileCheck --check-prefixes=CHECK,PROF %s
+//
+// RUN: %clang -### -target x86_64-linux-gnu -c --cuda-gpu-arch=sm_20 \
+// RUN:   -fprofile-instr-generate %s 2>&1 | \
+// RUN: FileCheck --check-prefixes=CHECK,PROF %s
+//
+// RUN: %clang -### -target x86_64-linux-gnu -c --cuda-gpu-arch=sm_20 \
+// RUN:   -coverage %s 2>&1 | \
+// RUN: FileCheck --check-prefixes=CHECK,GCOV %s
+//
+// RUN: %clang -### -target x86_64-linux-gnu -c --cuda-gpu-arch=sm_20 \
+// RUN:   -ftest-coverage %s 2>&1 | \
+// RUN: FileCheck --check-prefixes=CHECK,GCOV %s
+//
+// RUN: %clang -### -target x86_64-linux-gnu -c --cuda-gpu-arch=sm_20   \
+// RUN:   -fprofile-instr-generate -fcoverage-mapping %s 2>&1 | \
+// RUN: FileCheck --check-prefixes=CHECK,PROF,GCOV %s
+//
+//
+// CHECK-NOT: error: unsupported option '-fprofile
+// CHECK-NOT: error: invalid argument
+// CHECK-DAG: "-fcuda-is-device"
+// CHECK-NOT: "-f{{[^"]*coverage.*}}"
+// CHECK-NOT: "-fprofile{{[^"]*}}"
+// CHECK: "-triple" "x86_64--linux-gnu"
+// PROF-DAG: "-fprofile{{.*}}"
+// GCOV-DAG: "-f{{(coverage|emit-coverage).*}}"
Index: clang/lib/Driver/ToolChains/Clang.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Clang.cpp
+++ clang/lib/Driver/ToolChains/Clang.cpp
@@ -3625,7 +3625,11 @@
       options::OPT_finstrument_function_entry_bare))
     A->render(Args, CmdArgs);
 
-  addPGOAndCoverageFlags(C, D, Output, Args, CmdArgs);
+  // NVPTX doesn't support PGO or coverage. There's no runtime support for
+  // sampling, overhead of call arc collection is way too high and there's no
+  // way to collect the output.
+  if (!Triple.isNVPTX())
+    addPGOAndCoverageFlags(C, D, Output, Args, CmdArgs);
 
   if (auto *ABICompatArg = Args.getLastArg(options::OPT_fclang_abi_compat_EQ))
     ABICompatArg->render(Args, CmdArgs);


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