[Bug tree-optimization/92683] [10 Regression] strncmp incorrect result with equal substrings and non-const bound

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92683

--- Comment #1 from Martin Sebor <msebor at gcc dot gnu.org> ---
Author: msebor
Date: Tue Nov 26 23:56:22 2019
New Revision: 278742

URL: https://gcc.gnu.org/viewcvs?rev=278742&root=gcc&view=rev
Log:
PR tree-optimization/92683 - strncmp incorrect result with equal substrings and
non-const bound

gcc/testsuite/ChangeLog:

        PR tree-optimization/92683
        * gcc.dg/strcmpopt_8.c: New test.
        * gcc.dg/strcmpopt_9.c: New test.

gcc/ChangeLog:

        PR tree-optimization/92683
        * gimple-fold.c (gimple_fold_builtin_string_compare): Restore a test
        inadvertently removed in a previous change.  Rename local variable
        for clarity.

Added:
    trunk/gcc/testsuite/gcc.dg/strcmpopt_8.c
    trunk/gcc/testsuite/gcc.dg/strcmpopt_9.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/gimple-fold.c
    trunk/gcc/testsuite/ChangeLog