[Bug tree-optimization/77536] Vectorizer not maintaining relationship of relative block frequencies in absence of real profile data

["amker at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77536

--- Comment #7 from amker at gcc dot gnu.org ---
Author: amker
Date: Mon Feb 27 10:20:36 2017
New Revision: 245754

URL: https://gcc.gnu.org/viewcvs?rev=245754&root=gcc&view=rev
Log:
        PR tree-optimization/77536
        * tree-ssa-loop-manip.c (niter_for_unrolled_loop): New function.
        (tree_transform_and_unroll_loop): Use above function to compute the
        estimated niter of unrolled loop and use it when scaling profile.
        Also use count info rather than frequency if it's non-zero.
        * tree-ssa-loop-manip.h niter_for_unrolled_loop(): New declaration.
        * tree-vect-loop.c (scale_profile_for_vect_loop): New function.
        (vect_transform_loop): Call above function.

        gcc/testsuite
        * gcc.dg/vect/pr79347.c: Revise testing string.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gcc.dg/vect/pr79347.c
    trunk/gcc/tree-ssa-loop-manip.c
    trunk/gcc/tree-ssa-loop-manip.h
    trunk/gcc/tree-vect-loop.c