This is the mail archive of the
cygwin@cygwin.com
mailing list for the Cygwin project.
1.3.10 memcmp() bug
- From: Sami Korhonen <ssakorho at messi dot uku dot fi>
- To: cygwin at cygwin dot com
- Date: Wed, 24 Apr 2002 08:04:03 +0300 (WET)
- Subject: 1.3.10 memcmp() bug
I wasnt sure wheter I should post about this on gcc bug report list or
here. Anyways, it seems that using -O2 flag with gcc causes huge slowdown
in memcmp(). However i dont see performance drop under linux, so I suppose
it is cygwin issue.
$ gcc memtest.c -O2 -o memtest ; ./memtest.exe
Amount of memory to scan (mbytes)? 100
Memory block size (default 1024)? 1024
Allocating memory
Testing memory - read (1 byte at time)
Complete: 889.73MB/sec
Testing memory - read (4 bytes at time)
Complete: 3313.07MB/sec
Freeing memory
$ gcc memtest.c -o memtest ; ./memtest.exe
Amount of memory to scan (mbytes)? 100
Memory block size (default 1024)? 1024
Allocating memory
Testing memory - read (1 byte at time)
Complete: 2517.94MB/sec
Testing memory - read (4 bytes at time)
Complete: 2933.50MB/sec
Freeing memory
'1 byte at time' is using memcmp() to compare two blocks.
--
Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
Bug reporting: http://cygwin.com/bugs.html
Documentation: http://cygwin.com/docs.html
FAQ: http://cygwin.com/faq/