https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78534
--- Comment #26 from Janne Blomqvist <jb at gcc dot gnu.org> --- Author: jb Date: Wed Jan 31 13:23:20 2018 New Revision: 257233 URL: https://gcc.gnu.org/viewcvs?rev=257233&root=gcc&view=rev Log: PR 78534 Reinstate better string copy algorithm As part of the change to larger character lengths, the string copy algorithm was temporarily pessimized to get around some spurious -Wstringop-overflow warnings. Having tried a number of variations of this algorithm I have managed to get it down to one spurious warning, only with -O1 optimization, in the testsuite. This patch reinstates the optimized variant and modifies this one testcase to ignore the warning. Regtested on x86_64-pc-linux-gnu. gcc/fortran/ChangeLog: 2018-01-31 Janne Blomqvist <j...@gcc.gnu.org> PR fortran/78534 * trans-expr.c (fill_with_spaces): Use memset instead of generating loop. (gfc_trans_string_copy): Improve opportunity to use builtins with constant lengths. gcc/testsuite/ChangeLog: 2018-01-31 Janne Blomqvist <j...@gcc.gnu.org> PR fortran/78534 * gfortran.dg/allocate_deferred_char_scalar_1.f03: Prune -Wstringop-overflow warnings due to spurious warning with -O1. * gfortran.dg/char_cast_1.f90: Update dump scan pattern. * gfortran.dg/transfer_intrinsic_1.f90: Likewise. Modified: trunk/gcc/fortran/ChangeLog trunk/gcc/fortran/trans-expr.c trunk/gcc/testsuite/ChangeLog trunk/gcc/testsuite/gfortran.dg/allocate_deferred_char_scalar_1.f03 trunk/gcc/testsuite/gfortran.dg/char_cast_1.f90 trunk/gcc/testsuite/gfortran.dg/transfer_intrinsic_1.f90
