[Bug libfortran/38199] [4.7/4.8/4.9 Regression] missed optimization: I/O performance

["jvdelisle at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38199

--- Comment #44 from Jerry DeLisle <jvdelisle at gcc dot gnu.org> ---
Author: jvdelisle
Date: Sat Mar 15 23:06:44 2014
New Revision: 208599

URL: http://gcc.gnu.org/viewcvs?rev=208599&root=gcc&view=rev
Log:
2014-03-15  Jerry DeLisle  <jvdelisle@gcc.gnu>

    Backport from mainline
    PR libfortran/58324
    PR libfortran/38199
    * intrinsics/string_intriniscs_inc.c (string_len_trim):
    Remove prototypes for string_len_trim and move to...
    * libgfortran.h (string_len_trim): ... here and
    (string_len_trim_char4): ...here.
    * io/list_read.c (finish_list_read): Read one character to check
    for the end of the file.  If it is the end, then issue the file
    end error message.  If not, use eat_line to reach the end
    without giving error.  The next attempt to read will then
    issue the error as described above.
    * io/read.c (read_decimal): Quickly skip spaces to avoid calls
    to next_char.
    * io/unit.c (is_trim_ok): New helper function to check various
    conditions to see if its OK to trim the internal unit string.
    (get_internal_unit): Use LEN_TRIM to shorten selected internal
    unit strings for optimizing READ. Enable this optimization for
    formatted READ.

    Backport from mainline
    PR libfortran/58324
    * gfortran.dg/list_read_12.f90: New test.

Added:
    branches/gcc-4_7-branch/gcc/testsuite/gfortran.dg/list_read_12.f90
Modified:
    branches/gcc-4_7-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_7-branch/libgfortran/ChangeLog
    branches/gcc-4_7-branch/libgfortran/intrinsics/string_intrinsics_inc.c
    branches/gcc-4_7-branch/libgfortran/io/list_read.c
    branches/gcc-4_7-branch/libgfortran/io/read.c
    branches/gcc-4_7-branch/libgfortran/io/unit.c
    branches/gcc-4_7-branch/libgfortran/libgfortran.h