[Patch] Fix libstdc++/11378

[Paolo Carlini]

Hi,

the below is essentially the fix I have already presented
yesterday together with some satisfying numbers:

  http://gcc.gnu.org/ml/libstdc++/2003-07/msg00025.html

I meant to also implement in one shot a few other
performance improvements belonging to the filebuf::xsputn
virtual but turned out to be a little more tricky than
I hoped for... ;)

Therefore, for the time being, I propose to close the PR
and add the corresponding performance testcase.

Tested x86-linux.

Ok?

Paolo.

////////
-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: CL_11378
URL: <http://gcc.gnu.org/pipermail/libstdc++/attachments/20030703/03189756/attachment.ksh>
-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: patch_11378
URL: <http://gcc.gnu.org/pipermail/libstdc++/attachments/20030703/03189756/attachment-0001.ksh>