libstdc++/10672: Binary IO with fstream is slow in 3.2+ compared to gcc 2.96

[paolo@gcc.gnu.org]

Synopsis: Binary IO with fstream is slow in 3.2+ compared to gcc 2.96

State-Changed-From-To: open->feedback
State-Changed-By: paolo
State-Changed-When: Sun May 18 08:25:00 2003
State-Changed-Why:
    This is already fixed in mainline (future 3.4).
    On my P4-2400, 10^6 iterations, 5 consecutive runs:
    2.96-99 (NB: *not* an official FSF release):
    -------
    2.630u 4.970s 0:07.64 99.4%     0+0k 0+0io 136pf+0w
    2.660u 4.930s 0:07.62 99.6%     0+0k 0+0io 136pf+0w
    2.790u 5.120s 0:07.97 99.2%     0+0k 0+0io 136pf+0w
    2.720u 4.840s 0:07.59 99.6%     0+0k 0+0io 136pf+0w
    2.830u 4.670s 0:07.54 99.4%     0+0k 0+0io 136pf+0w
    
    3.4 20030516
    ------------
    2.500u 4.790s 0:07.34 99.3%     0+0k 0+0io 217pf+0w
    2.570u 4.690s 0:07.31 99.3%     0+0k 0+0io 217pf+0w
    2.350u 4.990s 0:07.38 99.4%     0+0k 0+0io 217pf+0w
    2.650u 4.670s 0:07.38 99.1%     0+0k 0+0io 217pf+0w
    2.590u 4.720s 0:07.35 99.4%     0+0k 0+0io 217pf+0w
    
    Could you please provide one of those nasty testcases
    which were showing a 5x performance regression?
    
    Thanks for your report, Paolo.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=10672