[Bug tree-optimization/69070] [6 Regression] ICE: tree check: expected real_cst, have ssa_name in gimple_expand_builtin_pow, at tree-ssa-math-opts.c:1541 with -fsignaling-nans and powl()

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69070

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2015-12-29
           Assignee|unassigned at gcc dot gnu.org      |jakub at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 37183
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=37183&action=edit
gcc6-pr69070.patch

Caused by r231901.
Untested fix attached.  IMHO if the first argument is not a REAL_CST, then the
optimization might transform the pow into say sqrt, cbrt, multiplication etc.,
but all those should still raise exceptions on sNaN.