Hello,
here is a fix for a wrong code issue, where we pass a descriptor with
broken bounds when the actual argument is a transposed array and the
dummy an assumed shape dummy.
The bug comes from the interaction of the transpose optimization,
which creates a descriptor with transposed bounds without copying the
data, and the contiguous optimization, which reuses the descriptor for
passing as argument after the call to internal_pack.
The attached patch makes a copy of the descriptor with the correct
bounds when a transposed scalarization is detected.
Regression-tested on x86_64-unknown-linux-gnu.
This is not a regression as far as I know, but quite a severe
wrong-code, albeit limited to the corner case of transpose and
assumed shape and contiguous. OK for trunk/4.8/4.7 anyway ?
Mikael
PS: To not reproduce the same mistake as in the PR regarding the memory
representation of matrices, I have filled the matrices one element at a
time in the testcase.
2014-03-09 Mikael Morin <[email protected]>
PR fortran/60392
* trans-array.c (gfc_conv_array_parameter): Don't reuse the descriptor
if it has transposed dimensions.
2014-03-09 Mikael Morin <[email protected]>
PR fortran/60392
* gfortran.dg/transpose_4.f90: New test.
Index: trans-array.c
===================================================================
--- trans-array.c (révision 208442)
+++ trans-array.c (copie de travail)
@@ -7227,7 +7227,50 @@ gfc_conv_array_parameter (gfc_se * se, gfc_expr *
else
{
tmp = build_fold_indirect_ref_loc (input_location, desc);
- gfc_conv_descriptor_data_set (&se->pre, tmp, ptr);
+
+ gfc_ss * ss = gfc_walk_expr (expr);
+ if (!transposed_dims (ss))
+ gfc_conv_descriptor_data_set (&se->pre, tmp, ptr);
+ else
+ {
+ tree old_field, new_field;
+
+ /* The original descriptor has transposed dims so we can't reuse
+ it directly; we have to create a new one. */
+ tree old_desc = tmp;
+ tree new_desc = gfc_create_var (TREE_TYPE (old_desc), "arg_desc");
+
+ old_field = gfc_conv_descriptor_dtype (old_desc);
+ new_field = gfc_conv_descriptor_dtype (new_desc);
+ gfc_add_modify (&se->pre, new_field, old_field);
+
+ old_field = gfc_conv_descriptor_offset (old_desc);
+ new_field = gfc_conv_descriptor_offset (new_desc);
+ gfc_add_modify (&se->pre, new_field, old_field);
+
+ for (int i = 0; i < expr->rank; i++)
+ {
+ old_field = gfc_conv_descriptor_dimension (old_desc,
+ gfc_rank_cst[get_array_ref_dim_for_loop_dim (ss, i)]);
+ new_field = gfc_conv_descriptor_dimension (new_desc,
+ gfc_rank_cst[i]);
+ gfc_add_modify (&se->pre, new_field, old_field);
+ }
+
+ if (gfc_option.coarray == GFC_FCOARRAY_LIB
+ && GFC_DESCRIPTOR_TYPE_P (TREE_TYPE (old_desc))
+ && GFC_TYPE_ARRAY_AKIND (TREE_TYPE (old_desc))
+ == GFC_ARRAY_ALLOCATABLE)
+ {
+ old_field = gfc_conv_descriptor_token (old_desc);
+ new_field = gfc_conv_descriptor_token (new_desc);
+ gfc_add_modify (&se->pre, new_field, old_field);
+ }
+
+ gfc_conv_descriptor_data_set (&se->pre, new_desc, ptr);
+ se->expr = gfc_build_addr_expr (NULL_TREE, new_desc);
+ }
+ gfc_free_ss (ss);
}
if (gfc_option.rtcheck & GFC_RTCHECK_ARRAY_TEMPS)
! { dg-do run }
!
! PR fortran/60392
! In the transposed case call to my_mul_cont, the compiler used to (wrongly)
! reuse a transposed descriptor for an array that was not transposed as a result
! of packing.
!
! Original test case from Alexander Vogt <[email protected]>.
program test
implicit none
integer, dimension(2,2) :: A, R, RT
integer, dimension(2,2) :: B1, B2
!
! A = [ 2 17 ]
! [ 82 257 ]
!
! matmul(a,a) = [ 1398 4403 ]
! [ 21238 67443 ]
!
! matmul(transpose(a), a) = [ 6728 21108 ]
! [ 21108 66338 ]
A(1,1) = 2
A(1,2) = 17
A(2,1) = 82
A(2,2) = 257
R(1,1) = 1398
R(1,2) = 4403
R(2,1) = 21238
R(2,2) = 67443
RT(1,1) = 6728
RT(1,2) = 21108
RT(2,1) = 21108
RT(2,2) = 66338
! Normal argument
B1 = 0
B2 = 0
B1 = my_mul(A,A)
B2 = my_mul_cont(A,A)
! print *,'Normal: ',maxval(abs(B1-B2))
! print *,B1
! print *,B2
if (any(B1 /= R)) call abort
if (any(B2 /= R)) call abort
! Transposed argument
B1 = 0
B2 = 0
B1 = my_mul(transpose(A),A)
B2 = my_mul_cont(transpose(A),A)
! print *,'Transposed:',maxval(abs(B1-B2))
! print *,B1
! print *,B2
if (any(B1 /= RT)) call abort
if (any(B2 /= RT)) call abort
contains
function my_mul(A,C) result (B)
use, intrinsic :: ISO_Fortran_env
integer, intent(in) :: A(2,2), C(2,2)
integer :: B(2,2)
B = matmul(A, C)
end function
function my_mul_cont(A,C) result (B)
use, intrinsic :: ISO_Fortran_env
integer, intent(in), contiguous :: A(:,:), C(:,:)
integer :: B(2,2)
B = matmul(A, C)
end function
end program
