[Bug tree-optimization/86835] [8 Regression] Bogus "is used uninitialized" warning with -ffast-math

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86835

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Wed Sep  5 07:21:15 2018
New Revision: 264106

URL: https://gcc.gnu.org/viewcvs?rev=264106&root=gcc&view=rev
Log:
        Backported from mainline
        2018-08-11  Jakub Jelinek  <jakub@redhat.com>

        PR tree-optimization/86835
        * tree-ssa-math-opts.c (insert_reciprocals): Even when inserting
        new_stmt after def_gsi, make sure to insert new_square_stmt after
        that stmt, not 2 stmts before it.

        * gcc.dg/pr86835.c: New test.

Added:
    branches/gcc-8-branch/gcc/testsuite/gcc.dg/pr86835.c
Modified:
    branches/gcc-8-branch/gcc/ChangeLog
    branches/gcc-8-branch/gcc/testsuite/ChangeLog
    branches/gcc-8-branch/gcc/tree-ssa-math-opts.c