[Bug tree-optimization/92131] [8/9/10 Regression] incorrect assumption that (ao >= 0) is always false

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92131

--- Comment #20 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
Author: ebotcazou
Date: Wed Oct 23 11:34:48 2019
New Revision: 277314

URL: https://gcc.gnu.org/viewcvs?rev=277314&root=gcc&view=rev
Log:
        PR tree-optimization/92131
        * tree-vrp.c (extract_range_from_plus_minus_expr): If the resulting
        range would be symbolic, drop to varying for any explicit overflow
        in the constant part or if neither range is a singleton.

Added:
    trunk/gcc/testsuite/gcc.c-torture/execute/20191023-1.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-vrp.c