[Bug tree-optimization/80281] [5/6/7 Regression] Wrong constant folding

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80281

--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> ---
So

 /* A + (-B) -> A - B */
 (simplify
  (plus:c (convert1? @0) (convert2? (negate @1)))
  /* Apply STRIP_NOPS on @0 and the negate.  */
  (if (tree_nop_conversion_p (type, TREE_TYPE (@0))
       && tree_nop_conversion_p (type, TREE_TYPE (@1))
       && !TYPE_OVERFLOW_SANITIZED (type))
   (with
    {
     tree t1 = type;
     if (TYPE_OVERFLOW_WRAPS (type) != TYPE_OVERFLOW_WRAPS (TREE_TYPE (@1)))
       t1 = TYPE_OVERFLOW_WRAPS (type) ? type : TREE_TYPE (@1);
    }
    (convert (minus (convert:t1 @0) (convert:t1 @1))))))