[Flang][OpenMP][MLIR] Initial declare target to for variables implementation

While the infrastructure for declare target to/enter and link for variables exists in the MLIR dialect and at the Flang level, the current lowering from MLIR -> LLVM IR isn't in place, it's only in place for variables that have the link clause applied.

This PR aims to extend that lowering to an initial implementation that incorporates declare target to as well, which primarily requires changes in the OpenMPToLLVMIRTranslation phase. However, a minor addition to the OpenMP dialect was required to extend the declare target enumerator to include a default None field as well.

This also requires a minor change to the Flang lowering's MapInfoFinlization.cpp pass to alter the map type for descriptors to deal with cases where a variable is marked declare to.  Currently, when a descriptor variable is mapped declare target to the  descriptor component can become attatched, and cannot be updated, this results in issues when an unusual allocation range is specified (effectively an off-by X error). The current solution is to map the descriptor always, as we always require an up-to-date version of this data. However, this also requires an interlinked PR that adds a more intricate type of mapping of structures/record types that clang currently implements, to circumvent the overwriting of the pointer in the descriptor.

3/3 required PRs to enable declare target to mapping, this PR should pass all tests and provide an all green CI.

Co-authored-by: Raghu Maddhipatla [email protected]

Author: agozillon

flang/lib/Optimizer/OpenMP/MapInfoFinalization.cpp

@@ -237,8 +237,10 @@ class MapInfoFinalizationPass
     return llvm::to_underlying(
         hasImplicitMap
             ? llvm::omp::OpenMPOffloadMappingFlags::OMP_MAP_TO |
-                  llvm::omp::OpenMPOffloadMappingFlags::OMP_MAP_IMPLICIT
-            : llvm::omp::OpenMPOffloadMappingFlags::OMP_MAP_TO);
+                  llvm::omp::OpenMPOffloadMappingFlags::OMP_MAP_IMPLICIT |
+                  llvm::omp::OpenMPOffloadMappingFlags::OMP_MAP_ALWAYS
+            : llvm::omp::OpenMPOffloadMappingFlags::OMP_MAP_TO |
+                  llvm::omp::OpenMPOffloadMappingFlags::OMP_MAP_ALWAYS);
   }
 
   mlir::omp::MapInfoOp genDescriptorMemberMaps(mlir::omp::MapInfoOp op,

flang/test/Lower/OpenMP/allocatable-array-bounds.f90

@@ -24,7 +24,7 @@
 !HOST: %[[BOUNDS_1:.*]] = omp.map.bounds lower_bound(%[[LB_1]] : index) upper_bound(%[[UB_1]] : index) extent(%[[BOX_3]]#1 : index) stride(%[[BOX_2]]#2 : index) start_idx(%[[BOX_1]]#0 : index) {stride_in_bytes = true}
 !HOST: %[[VAR_PTR_PTR:.*]] = fir.box_offset %[[DECLARE_1]]#1 base_addr : (!fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>) -> !fir.llvm_ptr<!fir.ref<!fir.array<?xi32>>>
 !HOST: %[[MAP_INFO_MEMBER:.*]] = omp.map.info var_ptr(%[[DECLARE_1]]#1 : !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>, !fir.array<?xi32>) var_ptr_ptr(%[[VAR_PTR_PTR]] : !fir.llvm_ptr<!fir.ref<!fir.array<?xi32>>>) map_clauses(tofrom) capture(ByRef) bounds(%[[BOUNDS_1]]) -> !fir.llvm_ptr<!fir.ref<!fir.array<?xi32>>> {name = ""}    
-!HOST: %[[MAP_INFO_1:.*]] = omp.map.info var_ptr(%[[DECLARE_1]]#1 : !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>, !fir.box<!fir.heap<!fir.array<?xi32>>>) map_clauses(to) capture(ByRef) members(%[[MAP_INFO_MEMBER]] : [0] : !fir.llvm_ptr<!fir.ref<!fir.array<?xi32>>>) -> !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>> {name = "sp_read(2:5)"}
+!HOST: %[[MAP_INFO_1:.*]] = omp.map.info var_ptr(%[[DECLARE_1]]#1 : !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>, !fir.box<!fir.heap<!fir.array<?xi32>>>) map_clauses(always, to) capture(ByRef) members(%[[MAP_INFO_MEMBER]] : [0] : !fir.llvm_ptr<!fir.ref<!fir.array<?xi32>>>) -> !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>> {name = "sp_read(2:5)"}
 
 !HOST: %[[LOAD_3:.*]] = fir.load %[[DECLARE_2]]#0 : !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>
 !HOST: %[[LOAD_4:.*]] = fir.load %[[DECLARE_2]]#1 : !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>
@@ -42,7 +42,7 @@
 !HOST: %[[BOUNDS_2:.*]] = omp.map.bounds lower_bound(%[[LB_2]] : index) upper_bound(%[[UB_2]] : index) extent(%[[BOX_5]]#1 : index) stride(%[[BOX_4]]#2 : index) start_idx(%[[BOX_3]]#0 : index) {stride_in_bytes = true}
 !HOST: %[[VAR_PTR_PTR:.*]] = fir.box_offset %[[DECLARE_2]]#1 base_addr : (!fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>) -> !fir.llvm_ptr<!fir.ref<!fir.array<?xi32>>>
 !HOST: %[[MAP_INFO_MEMBER:.*]] = omp.map.info var_ptr(%[[DECLARE_2]]#1 : !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>, !fir.array<?xi32>) var_ptr_ptr(%[[VAR_PTR_PTR]] : !fir.llvm_ptr<!fir.ref<!fir.array<?xi32>>>) map_clauses(tofrom) capture(ByRef) bounds(%[[BOUNDS_2]]) -> !fir.llvm_ptr<!fir.ref<!fir.array<?xi32>>> {name = ""}    
-!HOST: %[[MAP_INFO_2:.*]] = omp.map.info var_ptr(%[[DECLARE_2]]#1 : !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>, !fir.box<!fir.heap<!fir.array<?xi32>>>) map_clauses(to) capture(ByRef) members(%[[MAP_INFO_MEMBER]] : [0] : !fir.llvm_ptr<!fir.ref<!fir.array<?xi32>>>) -> !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>> {name = "sp_write(2:5)"}
+!HOST: %[[MAP_INFO_2:.*]] = omp.map.info var_ptr(%[[DECLARE_2]]#1 : !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>, !fir.box<!fir.heap<!fir.array<?xi32>>>) map_clauses(always, to) capture(ByRef) members(%[[MAP_INFO_MEMBER]] : [0] : !fir.llvm_ptr<!fir.ref<!fir.array<?xi32>>>) -> !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>> {name = "sp_write(2:5)"}
 
 subroutine read_write_section()
     integer, allocatable :: sp_read(:)
@@ -81,7 +81,7 @@ module assumed_allocatable_array_routines
 !HOST: %[[BOUNDS:.*]] = omp.map.bounds lower_bound(%[[LB]] : index) upper_bound(%[[UB]] : index) extent(%[[BOX_3]]#1 : index) stride(%[[BOX_2]]#2 : index) start_idx(%[[BOX_1]]#0 : index) {stride_in_bytes = true}
 !HOST: %[[VAR_PTR_PTR:.*]] = fir.box_offset %[[DECLARE]]#1 base_addr : (!fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>) -> !fir.llvm_ptr<!fir.ref<!fir.array<?xi32>>>
 !HOST: %[[MAP_INFO_MEMBER:.*]] = omp.map.info var_ptr(%[[DECLARE]]#1 : !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>, !fir.array<?xi32>) var_ptr_ptr(%[[VAR_PTR_PTR]] : !fir.llvm_ptr<!fir.ref<!fir.array<?xi32>>>) map_clauses(tofrom) capture(ByRef) bounds(%[[BOUNDS]]) -> !fir.llvm_ptr<!fir.ref<!fir.array<?xi32>>> {name = ""}    
-!HOST: %[[MAP_INFO:.*]] = omp.map.info var_ptr(%[[DECLARE]]#1 : !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>, !fir.box<!fir.heap<!fir.array<?xi32>>>) map_clauses(to) capture(ByRef) members(%[[MAP_INFO_MEMBER]] : [0] : !fir.llvm_ptr<!fir.ref<!fir.array<?xi32>>>) -> !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>> {name = "arr_read_write(2:5)"}
+!HOST: %[[MAP_INFO:.*]] = omp.map.info var_ptr(%[[DECLARE]]#1 : !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>, !fir.box<!fir.heap<!fir.array<?xi32>>>) map_clauses(always, to) capture(ByRef) members(%[[MAP_INFO_MEMBER]] : [0] : !fir.llvm_ptr<!fir.ref<!fir.array<?xi32>>>) -> !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>> {name = "arr_read_write(2:5)"}
 subroutine assumed_shape_array(arr_read_write)
     integer, allocatable, intent(inout) :: arr_read_write(:)
 

flang/test/Lower/OpenMP/allocatable-map.f90

@@ -3,7 +3,7 @@
 !HLFIRDIALECT: %[[POINTER:.*]]:2 = hlfir.declare %0 {fortran_attrs = #fir.var_attrs<pointer>, uniq_name = "_QFpointer_routineEpoint"} : (!fir.ref<!fir.box<!fir.ptr<i32>>>) -> (!fir.ref<!fir.box<!fir.ptr<i32>>>, !fir.ref<!fir.box<!fir.ptr<i32>>>)
 !HLFIRDIALECT: %[[BOX_OFF:.*]] = fir.box_offset %[[POINTER]]#1 base_addr : (!fir.ref<!fir.box<!fir.ptr<i32>>>) -> !fir.llvm_ptr<!fir.ref<i32>>
 !HLFIRDIALECT: %[[POINTER_MAP_MEMBER:.*]] = omp.map.info var_ptr(%[[POINTER]]#1 : !fir.ref<!fir.box<!fir.ptr<i32>>>, i32) var_ptr_ptr(%[[BOX_OFF]] : !fir.llvm_ptr<!fir.ref<i32>>)  map_clauses(tofrom) capture(ByRef) -> !fir.llvm_ptr<!fir.ref<i32>> {name = ""}
-!HLFIRDIALECT: %[[POINTER_MAP:.*]] = omp.map.info var_ptr(%[[POINTER]]#1 : !fir.ref<!fir.box<!fir.ptr<i32>>>, !fir.box<!fir.ptr<i32>>) map_clauses(to) capture(ByRef) members(%[[POINTER_MAP_MEMBER]] : [0] : !fir.llvm_ptr<!fir.ref<i32>>) -> !fir.ref<!fir.box<!fir.ptr<i32>>> {name = "point"}
+!HLFIRDIALECT: %[[POINTER_MAP:.*]] = omp.map.info var_ptr(%[[POINTER]]#1 : !fir.ref<!fir.box<!fir.ptr<i32>>>, !fir.box<!fir.ptr<i32>>) map_clauses(always, to) capture(ByRef) members(%[[POINTER_MAP_MEMBER]] : [0] : !fir.llvm_ptr<!fir.ref<i32>>) -> !fir.ref<!fir.box<!fir.ptr<i32>>> {name = "point"}
 !HLFIRDIALECT: omp.target map_entries(%[[POINTER_MAP]] -> {{.*}}, %[[POINTER_MAP_MEMBER]] -> {{.*}} : !fir.ref<!fir.box<!fir.ptr<i32>>>, !fir.llvm_ptr<!fir.ref<i32>>) {
 subroutine pointer_routine()
     integer, pointer :: point 

flang/test/Lower/OpenMP/array-bounds.f90

@@ -52,7 +52,7 @@ module assumed_array_routines
 !HOST: %[[BOUNDS:.*]] = omp.map.bounds   lower_bound(%[[C3]] : index) upper_bound(%[[C4]] : index) extent(%[[DIMS1]]#1 : index) stride(%[[DIMS0]]#2 : index) start_idx(%[[C0]] : index) {stride_in_bytes = true}
 !HOST: %[[VAR_PTR_PTR:.*]] = fir.box_offset %0 base_addr : (!fir.ref<!fir.box<!fir.array<?xi32>>>) -> !fir.llvm_ptr<!fir.ref<!fir.array<?xi32>>>
 !HOST: %[[MAP_INFO_MEMBER:.*]] = omp.map.info var_ptr(%[[INTERMEDIATE_ALLOCA]] : !fir.ref<!fir.box<!fir.array<?xi32>>>, !fir.array<?xi32>) var_ptr_ptr(%[[VAR_PTR_PTR]] : !fir.llvm_ptr<!fir.ref<!fir.array<?xi32>>>) map_clauses(tofrom) capture(ByRef) bounds(%[[BOUNDS]]) -> !fir.llvm_ptr<!fir.ref<!fir.array<?xi32>>> {name = ""}
-!HOST: %[[MAP:.*]] = omp.map.info var_ptr(%[[INTERMEDIATE_ALLOCA]] : !fir.ref<!fir.box<!fir.array<?xi32>>>, !fir.box<!fir.array<?xi32>>) map_clauses(to) capture(ByRef) members(%[[MAP_INFO_MEMBER]] : [0] : !fir.llvm_ptr<!fir.ref<!fir.array<?xi32>>>) -> !fir.ref<!fir.array<?xi32>> {name = "arr_read_write(2:5)"}
+!HOST: %[[MAP:.*]] = omp.map.info var_ptr(%[[INTERMEDIATE_ALLOCA]] : !fir.ref<!fir.box<!fir.array<?xi32>>>, !fir.box<!fir.array<?xi32>>) map_clauses(always, to) capture(ByRef) members(%[[MAP_INFO_MEMBER]] : [0] : !fir.llvm_ptr<!fir.ref<!fir.array<?xi32>>>) -> !fir.ref<!fir.array<?xi32>> {name = "arr_read_write(2:5)"}
 !HOST: omp.target   map_entries(%[[MAP]] -> %{{.*}}, {{.*}} -> {{.*}}, %[[MAP_INFO_MEMBER]] -> %{{.*}} : !fir.ref<!fir.array<?xi32>>, !fir.ref<i32>, !fir.llvm_ptr<!fir.ref<!fir.array<?xi32>>>) {
     subroutine assumed_shape_array(arr_read_write)
             integer, intent(inout) :: arr_read_write(:)

flang/test/Lower/OpenMP/declare-target-link-tarop-cap.f90

@@ -35,7 +35,7 @@ program test_link
 
   allocate(test_ptr1)
   test_ptr1 = 1
-  !CHECK-DAG: {{%.*}} = omp.map.info var_ptr({{%.*}} : !fir.ref<!fir.box<!fir.ptr<i32>>>, !fir.box<!fir.ptr<i32>>) map_clauses(implicit, to) capture(ByRef) members({{%.*}} : !fir.llvm_ptr<!fir.ref<i32>>) -> !fir.ref<!fir.box<!fir.ptr<i32>>> {name = "test_ptr1"}
+  !CHECK-DAG: {{%.*}} = omp.map.info var_ptr({{%.*}} : !fir.ref<!fir.box<!fir.ptr<i32>>>, !fir.box<!fir.ptr<i32>>) map_clauses(always, implicit, to) capture(ByRef) members({{%.*}} : !fir.llvm_ptr<!fir.ref<i32>>) -> !fir.ref<!fir.box<!fir.ptr<i32>>> {name = "test_ptr1"}
   !$omp target
     test_ptr1 = test_ptr1 + 1
   !$omp end target
@@ -46,7 +46,7 @@ program test_link
   !$omp end target
 
 
-  !CHECK-DAG: {{%.*}} = omp.map.info var_ptr({{%.*}} : !fir.ref<!fir.box<!fir.ptr<i32>>>, !fir.box<!fir.ptr<i32>>) map_clauses(implicit, to) capture(ByRef) members({{%.*}} : !fir.llvm_ptr<!fir.ref<i32>>) -> !fir.ref<!fir.box<!fir.ptr<i32>>> {name = "test_ptr2"}
+  !CHECK-DAG: {{%.*}} = omp.map.info var_ptr({{%.*}} : !fir.ref<!fir.box<!fir.ptr<i32>>>, !fir.box<!fir.ptr<i32>>) map_clauses(always, implicit, to) capture(ByRef) members({{%.*}} : !fir.llvm_ptr<!fir.ref<i32>>) -> !fir.ref<!fir.box<!fir.ptr<i32>>> {name = "test_ptr2"}
   test_ptr2 => test_target
   !$omp target
     test_ptr2 = test_ptr2 + 1