[gcc r16-757] tree-chrec: Use signed_type_for in convert_affine_scev

[Jakub Jelinek]

https://gcc.gnu.org/g:e38027c8ff449ffadaca449004bb891b9094ad00

commit r16-757-ge38027c8ff449ffadaca449004bb891b9094ad00
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Tue May 20 08:21:14 2025 +0200

    tree-chrec: Use signed_type_for in convert_affine_scev
    
    On s390x-linux I've run into the gcc.dg/torture/bitint-27.c test ICEing in
    build_nonstandard_integer_type called from convert_affine_scev (not sure
    why it doesn't trigger on x86_64/aarch64).
    The problem is clear, when ct is a BITINT_TYPE with some large
    TYPE_PRECISION, build_nonstandard_integer_type won't really work on it.
    
    The patch fixes it similarly what has been done for GCC 14 in various
    other spots.
    
    2025-05-20  Jakub Jelinek  <jakub@redhat.com>
    
            * tree-chrec.cc (convert_affine_scev): Use signed_type_for instead of
            build_nonstandard_integer_type.

Diff:
---
 gcc/tree-chrec.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gcc/tree-chrec.cc b/gcc/tree-chrec.cc
index 38eb32916b86..a7c2f8de0d51 100644
--- a/gcc/tree-chrec.cc
+++ b/gcc/tree-chrec.cc
@@ -1490,7 +1490,7 @@ convert_affine_scev (class loop *loop, tree type,
   new_step = *step;
   if (TYPE_PRECISION (step_type) > TYPE_PRECISION (ct) && TYPE_UNSIGNED (ct))
     {
-      tree signed_ct = build_nonstandard_integer_type (TYPE_PRECISION (ct), 0);
+      tree signed_ct = signed_type_for (ct);
       new_step = chrec_convert (signed_ct, new_step, at_stmt,
                                 use_overflow_semantics);
     }