[Bug rtl-optimization/85811] Invalid optimization with fmax, fabs and nan

[glisse at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85811

--- Comment #6 from Marc Glisse <glisse at gcc dot gnu.org> ---
What does tree_expr_nonnegative_p call non-negative? A natural definition would
exclude NaN, but for REAL_CST we just return ! REAL_VALUE_NEGATIVE.