[Bug tree-optimization/64946] [AArch64] gcc.target/aarch64/vect-abs-compile.c - "abs" vectorization fails for char/short types

[vekumar at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64946

vekumar at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rguenth at gcc dot gnu.org

--- Comment #3 from vekumar at gcc dot gnu.org ---
Richard, 

As per your suggestion, adding a pattern for type demotion in match.pd solves
this.

(simplify
 ( convert (abs (convert@1 @0)))
 ( if (INTEGRAL_TYPE_P (type)
      /* We check for type compatibility between @0 and @1 below,
         so there's no need to check that @1/@3 are integral types.  */
      && INTEGRAL_TYPE_P (TREE_TYPE (@0))
      && INTEGRAL_TYPE_P (TREE_TYPE (@1))
      /* The precision of the type of each operand must match the
         precision of the mode of each operand, similarly for the
         result.  */
      && (TYPE_PRECISION (TREE_TYPE (@0))
          == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (@0))))
      && (TYPE_PRECISION (TREE_TYPE (@1))
          == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (@1))))
      && TYPE_PRECISION (type) == GET_MODE_PRECISION (TYPE_MODE (type))
      /* The inner conversion must be a widening conversion.  */
      && TYPE_PRECISION (TREE_TYPE (@1)) > TYPE_PRECISION (TREE_TYPE (@0))
      && ((GENERIC
           && (TYPE_MAIN_VARIANT (TREE_TYPE (@0))
               == TYPE_MAIN_VARIANT (type)))
          || (GIMPLE
              && types_compatible_p (TREE_TYPE (@0), type))))
   (abs @0)))


I have not yet tested it. Will it have implication on targets that does not
support vectorization with short/char types?