[flang-commits] [flang] [llvm] [Flang][LLVM][OpenMP] Relax target data restrictions to be more inline with the specification (PR #82537)

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https://github.com/agozillon created https://github.com/llvm/llvm-project/pull/82537

Currently we emit errors whenever a map is not provided on a target data directive, however, I believe that's incorrect behavior, the specification states:

"At least one map, use_device_addr or use_device_ptr clause must appear on the directive"

So provided one is present, the directive is legal in this case. Slightly different to its siblings (enter/exit/update) which don't have use_device_addr/use_device_ptr.

>From cda9de34fd9f670f52c321e63776827b5d858eb5 Mon Sep 17 00:00:00 2001
From: agozillon <Andrew.Gozillon at amd.com>
Date: Wed, 21 Feb 2024 15:23:04 -0600
Subject: [PATCH] [Flang][LLVM][OpenMP] Relax target data restrictions to be
 more in line with the specification

Currently we emit errors whenever a map is not provided on a target data
directive, however, that's incorrect behaviour,  the specification states:

"At least one map, use_device_addr or use_device_ptr clause must appear on the directive"

So provided one is present, the directive is legal in this case. Slightly different
to its siblings which don't have use_device_addr/use_device_ptr.
---
 flang/test/Semantics/OpenMP/device-constructs.f90 | 12 +++++++++++-
 llvm/include/llvm/Frontend/OpenMP/OMP.td          |  8 +++-----
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/flang/test/Semantics/OpenMP/device-constructs.f90 b/flang/test/Semantics/OpenMP/device-constructs.f90
index 51f00700b6daf7..1ac00ef922c6bd 100644
--- a/flang/test/Semantics/OpenMP/device-constructs.f90
+++ b/flang/test/Semantics/OpenMP/device-constructs.f90
@@ -2,9 +2,11 @@
 ! Check OpenMP clause validity for the following directives:
 !     2.10 Device constructs
 program main
+   use iso_c_binding
 
   real(8) :: arrayA(256), arrayB(256)
   integer :: N
+  type(c_ptr) :: cptr
 
   arrayA = 1.414
   arrayB = 3.14
@@ -135,7 +137,15 @@ program main
   enddo
   !$omp end target data
 
-  !ERROR: At least one of MAP clause must appear on the TARGET DATA directive
+  !$omp target data device(0) use_device_addr(cptr)
+   cptr = c_null_ptr
+  !$omp end target data
+
+  !$omp target data device(0) use_device_addr(cptr)
+   cptr = c_null_ptr
+  !$omp end target data
+
+  !ERROR: At least one of MAP, USE_DEVICE_ADDR, USE_DEVICE_PTR clause must appear on the TARGET DATA directive
   !$omp target data device(0)
   do i = 1, N
      a = 3.14
diff --git a/llvm/include/llvm/Frontend/OpenMP/OMP.td b/llvm/include/llvm/Frontend/OpenMP/OMP.td
index 1481328bf483b8..f44e8f18c99f6a 100644
--- a/llvm/include/llvm/Frontend/OpenMP/OMP.td
+++ b/llvm/include/llvm/Frontend/OpenMP/OMP.td
@@ -710,16 +710,14 @@ def OMP_Requires : Directive<"requires"> {
 }
 def OMP_Nothing : Directive<"nothing"> {}
 def OMP_TargetData : Directive<"target data"> {
-  let allowedClauses = [
-    VersionedClause<OMPC_UseDevicePtr>,
-    VersionedClause<OMPC_UseDeviceAddr, 50>
-  ];
   let allowedOnceClauses = [
     VersionedClause<OMPC_Device>,
     VersionedClause<OMPC_If>
   ];
   let requiredClauses = [
-    VersionedClause<OMPC_Map>
+    VersionedClause<OMPC_Map>,
+    VersionedClause<OMPC_UseDevicePtr>,
+    VersionedClause<OMPC_UseDeviceAddr, 50> 
   ];
 }
 def OMP_TargetEnterData : Directive<"target enter data"> {