[Bug c/46186] Clang creates code running 1600 times faster than gcc's

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46186

--- Comment #16 from Jakub Jelinek <jakub at gcc dot gnu.org> 2010-10-26 
18:43:40 UTC ---
chrec_apply is called with
{a_4(D), +, {a_4(D) + 1, +, 1}_1}_1
chrec and ~a_4(D) + b_5(D) in x.
I wonder if this can be fixed just by recognizing such special cases in
chrec_apply (after checking e.g. that it is unsigned computation instead of
signed etc.).