[PATCH][4.1] Fix PRs 27795, 27639, 26719 - wrong code with scev/loop

[Olivier Hainque]

Richard Guenther wrote:
> Bootstrapped and tested on x86_64-unknown-linux-gnu.  I'll apply to the
> branch in a sec.

 Thanks. Regarding:

*************** chrec_convert_aggressive (tree type, tre
*** 1305,1310 ****
--- 1324,1333 ----
    if (TYPE_PRECISION (type) > TYPE_PRECISION (inner_type))
      return NULL_TREE;
  
+   /* If we cannot perform arithmetic in TYPE, avoid creating an scev.  */
+   if (avoid_arithmetics_in_type_p (type))
+     return false;
+ 
    left = CHREC_LEFT (chrec);
    right = CHREC_RIGHT (chrec);
    lc = chrec_convert_aggressive (type, left);

 Isn't 'NULL_TREE' intended instead of 'false' ?