From 40342f5bb8ed4b0eb6acda01a80e96de6b6286a3 Mon Sep 17 00:00:00 2001
From: Valentin Clement <clementval@gmail.com>
Date: Tue, 4 Feb 2025 15:53:24 -0800
Subject: [PATCH] [flang][cuda][NFC] Add tests for device functions in cuf
 kernels

Using device function in cuf kernel is allowed but requires an
explicit use of the cudadevice module. The two added tests make
sur it works when the cudadevice module is used and failed when it
is not.
---
 flang/test/Lower/CUDA/cuda-device-proc.cuf | 14 ++++++++++++++
 flang/test/Semantics/cuf09.cuf             | 13 +++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/flang/test/Lower/CUDA/cuda-device-proc.cuf b/flang/test/Lower/CUDA/cuda-device-proc.cuf
index 7ef391c7d308b..5805dd5010a84 100644
--- a/flang/test/Lower/CUDA/cuda-device-proc.cuf
+++ b/flang/test/Lower/CUDA/cuda-device-proc.cuf
@@ -87,3 +87,17 @@ end
 ! CHECK: func.func private @llvm.nvvm.barrier0.and(i32) -> i32
 ! CHECK: func.func private @llvm.nvvm.barrier0.popc(i32) -> i32
 ! CHECK: func.func private @llvm.nvvm.barrier0.or(i32) -> i32
+
+subroutine host1()
+  integer, device :: a(32)
+  integer :: i, j
+
+block; use cudadevice
+  !$cuf kernel do(1) <<<*,32>>>
+  do i = 1, 32
+    a(i) = a(i) * 2.0
+    call syncthreads()
+    a(i) = a(i) + a(j) - 34.0
+  end do
+end block
+end 
diff --git a/flang/test/Semantics/cuf09.cuf b/flang/test/Semantics/cuf09.cuf
index fda8938b8ffc0..7d32e0d70ba36 100644
--- a/flang/test/Semantics/cuf09.cuf
+++ b/flang/test/Semantics/cuf09.cuf
@@ -192,3 +192,16 @@ program main
      enddo
   enddo
 end
+
+subroutine host1()
+  integer, device :: a(32)
+  integer :: i, j
+
+  !$cuf kernel do(1) <<<*,32>>>
+  do i = 1, 32
+    a(i) = a(i) * 2.0
+    !ERROR: 'syncthreads' may not be called in device code
+    call syncthreads() ! missing explicit use cudadevice
+    a(i) = a(i) + a(j) - 34.0
+  end do
+end