[Flang][OpenMP] Fix loop index privatisation with HLFIR

Loop index variables are privatised for a worksharing loop.
The alloca ops of the privatised index are hoisted to the
entry block of the outlineable region or parent function.
With HLFIR, the hlfir.declare should be created in the same
place as the alloca op. To achieve this the alloc and the
hflir.declare should be created in the same place. A new
function is created in OpenMP.cpp for this purpose.

Reviewed By: tblah

Differential Revision: https://reviews.llvm.org/D156719

flang/lib/Lower/OpenMP.cpp

@@ -1934,6 +1934,27 @@ static void resetBeforeTerminator(fir::FirOpBuilder &firOpBuilder,
     firOpBuilder.setInsertionPointToStart(&block);
 }
 
+static mlir::Operation *
+createAndSetPrivatizedLoopVar(Fortran::lower::AbstractConverter &converter,
+                              mlir::Location loc, mlir::Type loopVarType,
+                              mlir::Value indexVal,
+                              const Fortran::semantics::Symbol *sym) {
+  fir::FirOpBuilder &firOpBuilder = converter.getFirOpBuilder();
+  mlir::OpBuilder::InsertPoint insPt = firOpBuilder.saveInsertionPoint();
+  firOpBuilder.setInsertionPointToStart(firOpBuilder.getAllocaBlock());
+
+  mlir::Value temp = firOpBuilder.create<fir::AllocaOp>(
+      loc, loopVarType, /*pinned=*/true, /*lengthParams=*/mlir::ValueRange{},
+      /*shapeParams*/ mlir::ValueRange{},
+      llvm::ArrayRef<mlir::NamedAttribute>{
+          Fortran::lower::getAdaptToByRefAttr(firOpBuilder)});
+  converter.bindSymbol(*sym, temp);
+  firOpBuilder.restoreInsertionPoint(insPt);
+  mlir::Operation *storeOp = firOpBuilder.create<fir::StoreOp>(
+      loc, indexVal, converter.getSymbolAddress(*sym));
+  return storeOp;
+}
+
 /// Create the body (block) for an OpenMP Operation.
 ///
 /// \param [in]    op - the operation the body belongs to.
@@ -1974,14 +1995,10 @@ static void createBodyOfOp(
     // The argument is not currently in memory, so make a temporary for the
     // argument, and store it there, then bind that location to the argument.
     for (const Fortran::semantics::Symbol *arg : args) {
-      mlir::Value val =
+      mlir::Value indexVal =
           fir::getBase(op.getRegion().front().getArgument(argIndex));
-      mlir::Value temp = firOpBuilder.createTemporary(
-          loc, loopVarType,
-          llvm::ArrayRef<mlir::NamedAttribute>{
-              Fortran::lower::getAdaptToByRefAttr(firOpBuilder)});
-      storeOp = firOpBuilder.create<fir::StoreOp>(loc, val, temp);
-      converter.bindSymbol(*arg, temp);
+      storeOp = createAndSetPrivatizedLoopVar(converter, loc, loopVarType,
+                                              indexVal, arg);
       argIndex++;
     }
   } else {

flang/test/Lower/OpenMP/hlfir-wsloop.f90

@@ -0,0 +1,27 @@
+! This test checks lowering of OpenMP DO Directive with HLFIR.
+
+! RUN: bbc -hlfir -fopenmp -emit-fir %s -o - | FileCheck %s
+! RUN: %flang_fc1 -emit-fir -flang-experimental-hlfir -fopenmp %s -o - | FileCheck %s
+
+!CHECK-LABEL: func @_QPsimple_loop()
+subroutine simple_loop
+  integer :: i
+  ! CHECK-DAG:     %[[WS_ST:.*]] = arith.constant 1 : i32
+  ! CHECK-DAG:     %[[WS_END:.*]] = arith.constant 9 : i32
+  ! CHECK:  omp.parallel
+  !$OMP PARALLEL
+  ! CHECK-DAG:     %[[ALLOCA_IV:.*]] = fir.alloca i32 {{{.*}}, pinned}
+  ! CHECK:     %[[IV:.*]]    = fir.declare %[[ALLOCA_IV]] {uniq_name = "_QFsimple_loopEi"} : (!fir.ref<i32>) -> !fir.ref<i32>
+  ! CHECK:     omp.wsloop for (%[[I:.*]]) : i32 = (%[[WS_ST]]) to (%[[WS_END]]) inclusive step (%[[WS_ST]])
+  !$OMP DO
+  do i=1, 9
+  ! CHECK:             fir.store %[[I]] to %[[IV:.*]] : !fir.ref<i32>
+  ! CHECK:             %[[LOAD_IV:.*]] = fir.load %[[IV]] : !fir.ref<i32>
+  ! CHECK:    fir.call @_FortranAioOutputInteger32({{.*}}, %[[LOAD_IV]]) {{.*}}: (!fir.ref<i8>, i32) -> i1
+    print*, i
+  end do
+  ! CHECK:       omp.yield
+  !$OMP END DO
+  ! CHECK:       omp.terminator
+  !$OMP END PARALLEL
+end subroutine

flang/test/Lower/OpenMP/lastprivate-commonblock.f90

@@ -1,7 +1,7 @@
 ! RUN: %flang_fc1 -emit-fir -fopenmp -o - %s 2>&1 | FileCheck %s 
 
 !CHECK: func.func @_QPlastprivate_common() {
-!CHECK: %[[val_0:.*]] = fir.alloca i32 {adapt.valuebyref}
+!CHECK: %[[val_0:.*]] = fir.alloca i32 {adapt.valuebyref, pinned}
 !CHECK: %[[val_1:.*]] = fir.alloca i32 {bindc_name = "i", uniq_name = "_QFlastprivate_commonEi"}
 !CHECK: %[[val_2:.*]] = fir.address_of(@_QCc) : !fir.ref<!fir.array<8xi8>>
 !CHECK: %[[val_3:.*]] = fir.convert %[[val_2]] : (!fir.ref<!fir.array<8xi8>>) -> !fir.ref<!fir.array<?xi8>>

flang/test/Lower/OpenMP/stop-stmt-in-region.f90

@@ -71,7 +71,7 @@ subroutine test_stop_in_region3()
 end
 
 ! CHECK-LABEL: func.func @_QPtest_stop_in_region4() {
-! CHECK:         %[[VAL_0:.*]] = fir.alloca i32 {adapt.valuebyref}
+! CHECK:         %[[VAL_0:.*]] = fir.alloca i32 {adapt.valuebyref, pinned}
 ! CHECK:         %[[VAL_1:.*]] = fir.alloca i32 {bindc_name = "i", uniq_name = "_QFtest_stop_in_region4Ei"}
 ! CHECK:         %[[VAL_2:.*]] = fir.alloca i32 {bindc_name = "x", uniq_name = "_QFtest_stop_in_region4Ex"}
 ! CHECK:         %[[VAL_3:.*]] = arith.constant 1 : i32