[Bug tree-optimization/85814] [8 Regression] ICE Segmentation fault during GIMPLE pass: strlen -O3 and above

[rsandifo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85814

--- Comment #9 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> ---
Author: rsandifo
Date: Tue May 22 17:32:37 2018
New Revision: 260540

URL: https://gcc.gnu.org/viewcvs?rev=260540&root=gcc&view=rev
Log:
Fix tree-ssa-strlen handling of partial clobbers (PR85814)

Backport trunk fix (r260488).

2018-05-22  Richard Sandiford  <richard.sandiford@linaro.org>

gcc/
        PR tree-optimization/85814
        * tree-ssa-strlen.c (get_stridx_plus_constant): Cope with
        a null return from get_strinfo when unsharing the next
        strinfo in the chain.

gcc/testsuite/
        PR tree-optimization/85814
        * gcc.dg/torture/pr85814.c: New test.

Added:
    branches/gcc-8-branch/gcc/testsuite/gcc.dg/torture/pr85814.c
Modified:
    branches/gcc-8-branch/gcc/ChangeLog
    branches/gcc-8-branch/gcc/testsuite/ChangeLog
    branches/gcc-8-branch/gcc/tree-ssa-strlen.c