Dear All, the attached patch fixes an issue where array I/O is falsely optimized in the case when a section of an array pointer is involved, because the pointee can be non-contiguous. As we already scalarize the case of a full array with pointer attribute, we should do the same here.
Regtested on x86_64-pc-linux-gnu. OK for mainline? 15-backport? Thanks, Harald
From 2869d06a495f04fc75c4ce1b48fdf8cdf3dcdf05 Mon Sep 17 00:00:00 2001 From: Harald Anlauf <[email protected]> Date: Fri, 3 Oct 2025 21:16:19 +0200 Subject: [PATCH] Fortran: fix issue with I/O of array pointer [PR107968] PR fortran/107968 gcc/fortran/ChangeLog: * trans-io.cc (gfc_trans_transfer): Also scalarize I/O of section of an array pointer. gcc/testsuite/ChangeLog: * gfortran.dg/implied_do_io_9.f90: New test. --- gcc/fortran/trans-io.cc | 4 +- gcc/testsuite/gfortran.dg/implied_do_io_9.f90 | 72 +++++++++++++++++++ 2 files changed, 75 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/gfortran.dg/implied_do_io_9.f90 diff --git a/gcc/fortran/trans-io.cc b/gcc/fortran/trans-io.cc index df2fef70172..9360bddb30a 100644 --- a/gcc/fortran/trans-io.cc +++ b/gcc/fortran/trans-io.cc @@ -2646,7 +2646,9 @@ gfc_trans_transfer (gfc_code * code) && ((expr->symtree->n.sym->ts.type == BT_DERIVED && expr->ts.deferred) || (expr->symtree->n.sym->assoc && expr->symtree->n.sym->assoc->variable) - || gfc_expr_attr (expr).pointer)) + || gfc_expr_attr (expr).pointer + || (expr->symtree->n.sym->attr.pointer + && gfc_expr_attr (expr).target))) goto scalarize; /* With array-bounds checking enabled, force scalarization in some diff --git a/gcc/testsuite/gfortran.dg/implied_do_io_9.f90 b/gcc/testsuite/gfortran.dg/implied_do_io_9.f90 new file mode 100644 index 00000000000..5180b8ace66 --- /dev/null +++ b/gcc/testsuite/gfortran.dg/implied_do_io_9.f90 @@ -0,0 +1,72 @@ +! { dg-do run } +! { dg-additional-options "-O2" } +! +! PR fortran/107968 +! +! Verify that array I/O optimization is not used for a section +! of an array pointer as the pointee can be non-contiguous +! +! Contributed by Nils Dreier + +PROGRAM foo + implicit none + + TYPE t_geographical_coordinates + REAL :: lon + REAL :: lat + END TYPE t_geographical_coordinates + + TYPE t_vertices + REAL, POINTER :: vlon(:) => null() + REAL, POINTER :: vlat(:) => null() + END TYPE t_vertices + + TYPE(t_geographical_coordinates), TARGET :: vertex(2) + TYPE(t_vertices), POINTER :: vertices_pointer + TYPE(t_vertices), TARGET :: vertices_target + + character(24) :: s0, s1, s2 + character(*), parameter :: fmt = '(2f8.3)' + + ! initialization + vertex%lon = [1,3] + vertex%lat = [2,4] + + ! obtain pointer to (non-contiguous) field + vertices_target%vlon => vertex%lon + + ! reference output of write + write (s0,fmt) vertex%lon + + ! set pointer vertices_pointer in a subroutine + CALL set_vertices_pointer(vertices_target) + + write (s1,fmt) vertices_pointer%vlon + write (s2,fmt) vertices_pointer%vlon(1:) + if (s1 /= s0 .or. s2 /= s0) then + print *, s0, s1, s2 + stop 3 + end if + +CONTAINS + + SUBROUTINE set_vertices_pointer(vertices) + TYPE(t_vertices), POINTER, INTENT(IN) :: vertices + + vertices_pointer => vertices + + write (s1,fmt) vertices %vlon + write (s2,fmt) vertices %vlon(1:) + if (s1 /= s0 .or. s2 /= s0) then + print *, s0, s1, s2 + stop 1 + end if + + write (s1,fmt) vertices_pointer%vlon + write (s2,fmt) vertices_pointer%vlon(1:) + if (s1 /= s0 .or. s2 /= s0) then + print *, s0, s1, s2 + stop 2 + end if + END SUBROUTINE set_vertices_pointer +END PROGRAM foo -- 2.51.0
