[Bug tree-optimization/81913] [8 Regression] wrong code at -O1

[amker at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81913

--- Comment #6 from amker at gcc dot gnu.org ---
Author: amker
Date: Thu Aug 24 15:38:39 2017
New Revision: 251337

URL: https://gcc.gnu.org/viewcvs?rev=251337&root=gcc&view=rev
Log:
        PR tree-optimization/81913
        * tree-ssa-loop-niter.c (number_of_iterations_cond): Skip niter
        analysis when either IVs in condition can wrap.

        gcc/testsuite
        * gcc.c-torture/execute/pr81913.c: New test.
        * gcc.dg/tree-ssa/loop-niter-1.c: New test.
        * gcc.dg/tree-ssa/loop-niter-2.c: New test.

Added:
    trunk/gcc/testsuite/gcc.c-torture/execute/pr81913.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/loop-niter-1.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/loop-niter-2.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-loop-niter.c