[CUDA] Add -fcuda-flush-denormals-to-zero.

Summary:
Setting this flag causes all functions are annotated with the
"nvvm-f32ftz" = "true" attribute.

In addition, we annotate the module with "nvvm-reflect-ftz" set
to 0 or 1, depending on whether -cuda-flush-denormals-to-zero is set.
This is read by the NVVMReflect pass.

Reviewers: tra, rnk

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D18671

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@265435 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 23 insertions, 0 deletions

diff --git a/test/CodeGenCUDA/flush-denormals.cu b/test/CodeGenCUDA/flush-denormals.cu
new file mode 100644
index 0000000000..cab660254d
--- /dev/null
+++ b/test/CodeGenCUDA/flush-denormals.cu
@@ -0,0 +1,23 @@
+// RUN: %clang_cc1 -fcuda-is-device \
+// RUN:   -triple nvptx-nvidia-cuda -emit-llvm -o - %s | FileCheck %s -check-prefix NOFTZ
+// RUN: %clang_cc1 -fcuda-is-device -fcuda-flush-denormals-to-zero \
+// RUN:   -triple nvptx-nvidia-cuda -emit-llvm -o - %s | FileCheck %s -check-prefix FTZ
+
+#include "Inputs/cuda.h"
+
+// Checks that device function calls get emitted with the "ntpvx-f32ftz"
+// attribute set to "true" when we compile CUDA device code with
+// -fcuda-flush-denormals-to-zero.  Further, check that we reflect the presence
+// or absence of -fcuda-flush-denormals-to-zero in a module flag.
+
+// CHECK: define void @foo() #0
+extern "C" __device__ void foo() {}
+
+// FTZ: attributes #0 = {{.*}} "nvptx-f32ftz"="true"
+// NOFTZ-NOT: attributes #0 = {{.*}} "nvptx-f32ftz"
+
+// FTZ:!llvm.module.flags = !{[[MODFLAG:![0-9]+]]}
+// FTZ:[[MODFLAG]] = !{i32 4, !"nvvm-reflect-ftz", i32 1}
+
+// NOFTZ:!llvm.module.flags = !{[[MODFLAG:![0-9]+]]}
+// NOFTZ:[[MODFLAG]] = !{i32 4, !"nvvm-reflect-ftz", i32 0}