[flang-commits] [flang] [flang] prevent legacy lowering from being called in pointer assignment (PR #81750)

[via flang-commits]

https://github.com/jeanPerier created https://github.com/llvm/llvm-project/pull/81750

When doing a pointer assignment with an RHS that is an array section, the code fell in the legacy lowering code even with HLFIR enabled. Escape this old code when HLFIR is on.

Should fix #80884.

>From 6baa7b3dbc8753370ab301a634a2f77823207207 Mon Sep 17 00:00:00 2001
From: Jean Perier <jperier at nvidia.com>
Date: Wed, 14 Feb 2024 06:33:19 -0800
Subject: [PATCH] [flang] prevent legacy lowering from being called in pointer
 assignment

When doing a pointer assignment with an RHS that is an array section, the
code fell in the legacy lowering code even with HLFIR enabled.
Escape this old code when HLFIR is on.
---
 flang/lib/Lower/Bridge.cpp            |  9 +++++++-
 flang/test/Lower/HLFIR/issue80884.f90 | 32 +++++++++++++++++++++++++++
 2 files changed, 40 insertions(+), 1 deletion(-)
 create mode 100644 flang/test/Lower/HLFIR/issue80884.f90

diff --git a/flang/lib/Lower/Bridge.cpp b/flang/lib/Lower/Bridge.cpp
index 76e127207d764e..2d7f748cefa2d8 100644
--- a/flang/lib/Lower/Bridge.cpp
+++ b/flang/lib/Lower/Bridge.cpp
@@ -3419,6 +3419,13 @@ class FirConverter : public Fortran::lower::AbstractConverter {
       fir::factory::disassociateMutableBox(*builder, loc, lhs);
       return;
     }
+    if (lowerToHighLevelFIR()) {
+      fir::ExtendedValue rhs = genExprAddr(assign.rhs, stmtCtx);
+      fir::factory::associateMutableBoxWithRemap(*builder, loc, lhs, rhs,
+                                                 lbounds, ubounds);
+      return;
+    }
+    // Legacy lowering below.
     // Do not generate a temp in case rhs is an array section.
     fir::ExtendedValue rhs =
         Fortran::lower::isArraySectionWithoutVectorSubscript(assign.rhs)
@@ -3427,7 +3434,7 @@ class FirConverter : public Fortran::lower::AbstractConverter {
             : genExprAddr(assign.rhs, stmtCtx);
     fir::factory::associateMutableBoxWithRemap(*builder, loc, lhs, rhs, lbounds,
                                                ubounds);
-    if (!lowerToHighLevelFIR() && explicitIterationSpace()) {
+    if (explicitIterationSpace()) {
       mlir::ValueRange inners = explicitIterSpace.getInnerArgs();
       if (!inners.empty())
         builder->create<fir::ResultOp>(loc, inners);
diff --git a/flang/test/Lower/HLFIR/issue80884.f90 b/flang/test/Lower/HLFIR/issue80884.f90
new file mode 100644
index 00000000000000..2a7792b6004c4d
--- /dev/null
+++ b/flang/test/Lower/HLFIR/issue80884.f90
@@ -0,0 +1,32 @@
+! Test lowering of pointer remapping with component ref in the RHS.
+! RUN: bbc -emit-hlfir -o - %s -I nw | FileCheck %s
+
+subroutine issue80884(p, targ)
+  type t0
+    real :: array(10, 10)
+  end type
+  type, extends(t0) :: t
+  end type
+  type(t), target :: targ
+  real, pointer :: p(:)
+  p(1:100) => targ%array
+end subroutine
+! CHECK-LABEL:   func.func @_QPissue80884(
+! CHECK:           %[[VAL_2:.*]]:2 = hlfir.declare %{{.*}} {fortran_attrs = #fir.var_attrs<pointer>, uniq_name = "_QFissue80884Ep"} : (!fir.ref<!fir.box<!fir.ptr<!fir.array<?xf32>>>>) -> (!fir.ref<!fir.box<!fir.ptr<!fir.array<?xf32>>>>, !fir.ref<!fir.box<!fir.ptr<!fir.array<?xf32>>>>)
+! CHECK:           %[[VAL_3:.*]]:2 = hlfir.declare %{{.*}} {fortran_attrs = #fir.var_attrs<target>, uniq_name = "_QFissue80884Etarg"} : (!fir.ref<!fir.type<_QFissue80884Tt{t0:!fir.type<_QFissue80884Tt0{array:!fir.array<10x10xf32>}>}>>) -> (!fir.ref<!fir.type<_QFissue80884Tt{t0:!fir.type<_QFissue80884Tt0{array:!fir.array<10x10xf32>}>}>>, !fir.ref<!fir.type<_QFissue80884Tt{t0:!fir.type<_QFissue80884Tt0{array:!fir.array<10x10xf32>}>}>>)
+! CHECK:           %[[VAL_4:.*]] = arith.constant 1 : i64
+! CHECK:           %[[VAL_5:.*]] = arith.constant 100 : i64
+! CHECK:           %[[VAL_6:.*]] = hlfir.designate %[[VAL_3]]#0{"t0"}   : (!fir.ref<!fir.type<_QFissue80884Tt{t0:!fir.type<_QFissue80884Tt0{array:!fir.array<10x10xf32>}>}>>) -> !fir.ref<!fir.type<_QFissue80884Tt0{array:!fir.array<10x10xf32>}>>
+! CHECK:           %[[VAL_7:.*]] = arith.constant 10 : index
+! CHECK:           %[[VAL_8:.*]] = arith.constant 10 : index
+! CHECK:           %[[VAL_9:.*]] = fir.shape %[[VAL_7]], %[[VAL_8]] : (index, index) -> !fir.shape<2>
+! CHECK:           %[[VAL_10:.*]] = hlfir.designate %[[VAL_6]]{"array"}   shape %[[VAL_9]] : (!fir.ref<!fir.type<_QFissue80884Tt0{array:!fir.array<10x10xf32>}>>, !fir.shape<2>) -> !fir.ref<!fir.array<10x10xf32>>
+! CHECK:           %[[VAL_11:.*]] = arith.constant 1 : index
+! CHECK:           %[[VAL_12:.*]] = fir.convert %[[VAL_4]] : (i64) -> index
+! CHECK:           %[[VAL_13:.*]] = fir.convert %[[VAL_5]] : (i64) -> index
+! CHECK:           %[[VAL_14:.*]] = arith.subi %[[VAL_13]], %[[VAL_12]] : index
+! CHECK:           %[[VAL_15:.*]] = arith.addi %[[VAL_14]], %[[VAL_11]] : index
+! CHECK:           %[[VAL_16:.*]] = fir.convert %[[VAL_10]] : (!fir.ref<!fir.array<10x10xf32>>) -> !fir.ref<!fir.array<?xf32>>
+! CHECK:           %[[VAL_17:.*]] = fir.shape_shift %[[VAL_4]], %[[VAL_15]] : (i64, index) -> !fir.shapeshift<1>
+! CHECK:           %[[VAL_18:.*]] = fir.embox %[[VAL_16]](%[[VAL_17]]) : (!fir.ref<!fir.array<?xf32>>, !fir.shapeshift<1>) -> !fir.box<!fir.ptr<!fir.array<?xf32>>>
+! CHECK:           fir.store %[[VAL_18]] to %[[VAL_2]]#1 : !fir.ref<!fir.box<!fir.ptr<!fir.array<?xf32>>>>