From: Artem Belevich <tra@google.com>
Date: Wed, 24 Jan 2018 17:41:02 +0000 (+0000)
Subject: [CUDA] Disable PGO and coverage instrumentation in NVPTX.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=7e980e2e8ee6c9c9b2e7c0447f0b0d1a709baeb1;p=clang

[CUDA] Disable PGO and coverage instrumentation in NVPTX.

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.

Differential Revision: https://reviews.llvm.org/D42452

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@323345 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Driver/ToolChains/Clang.cpp b/lib/Driver/ToolChains/Clang.cpp
index f30782d8bf..1741517bff 100644
--- a/lib/Driver/ToolChains/Clang.cpp
+++ b/lib/Driver/ToolChains/Clang.cpp
@@ -3625,7 +3625,11 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
       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);
diff --git a/test/Driver/cuda-no-pgo-or-coverage.cu b/test/Driver/cuda-no-pgo-or-coverage.cu
new file mode 100644
index 0000000000..a2cb610f75
--- /dev/null
+++ b/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).*}}"