https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83354
Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |WAITING Last reconfirmed| |2017-12-11 CC| |rguenth at gcc dot gnu.org Ever confirmed|0 |1 --- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> --- We have that: (simplify (pows (cbrts tree_expr_nonnegative_p@0) @1) (pows @0 (mult @1 { build_real_truncate (type, dconst_third ()); }))) the constraint is that we have to know x is not negative. If you write pow(cbrt(fabs(x)), y) you'll see. So WORKSFORME?