https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90626
--- Comment #1 from Martin Sebor <msebor at gcc dot gnu.org> --- Author: msebor Date: Wed Jun 19 20:37:41 2019 New Revision: 272485 URL: https://gcc.gnu.org/viewcvs?rev=272485&root=gcc&view=rev Log: PR tree-optimization/90626 - fold strcmp(a, b) == 0 to zero when one string length is exact and the other is unequal gcc/ChangeLog: PR tree-optimization/90626 * tree-ssa-strlen.c (strxcmp_unequal): New function. (handle_builtin_string_cmp): Call it. gcc/testsuite/ChangeLog: PR tree-optimization/90626 * gcc.dg/strlenopt-65.c: New test. * gcc.dg/strlenopt-66.c: New test. * gcc.dg/strlenopt.h (strcmp, strncmp): Declare. Added: trunk/gcc/testsuite/gcc.dg/strlenopt-65.c trunk/gcc/testsuite/gcc.dg/strlenopt-66.c Modified: trunk/gcc/ChangeLog trunk/gcc/testsuite/ChangeLog trunk/gcc/testsuite/gcc.dg/strlenopt.h trunk/gcc/tree-ssa-strlen.c