[Bug rtl-optimization/96031] suboptimal codegen for store low 16-bits value

[zhongyunde at tom dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96031

--- Comment #4 from zhongyunde at tom dot com <zhongyunde at tom dot com> ---

> As for ivopt, I can see a minor improvement by replacing != exit condition
> with <=, thus saving add 2 instruction computing _22, which happens to
> "disable" the wrong PRE transformation.
> 
  I take a look at the function may_eliminate_iv, now iv_elimination_compare
will only return EQ_EXPR or NE_EXPR, so do you mean to do some extend for this
case?

5411   *bound = fold_convert (TREE_TYPE (cand->iv->base),
5412                          aff_combination_to_tree (&bnd));
5413   *comp = iv_elimination_compare (data, use);
5414