Re: performance issue with cgywin make

[Bill Hoffman]

Eli Zaretskii wrote:
> > Date: Fri, 08 Dec 2006 21:46:18 -0500
> > From: Bill Hoffman <address@hidden>
> >
> > So, the windows native stat is about 3 X faster.
> >     
>
> This is not really a valid conclusion: `stat' does much more than just
> get the file's attributes via a single Win32 API call.  And Make does
> use the result of the other API calls, such as st_ino, st_dev, and
> st_mode, for example.
>
>   
Since nmake is performing about 2X faster than gmake, the likely culprit 
is stat.
This all started because a cmake user was trying to switch from nmake to 
gmake,
and found it so much slower, then I remembered the change we made in cmake.
stat does do more, but I would assume that make is mostly interested in 
comparing
file modification times, and ignores the rest of those values.

I will poke around in the gmake sources and try to figure out if I can 
replace some
of the stat calls.  It looks like I can just change name_mtime in 
remake.c it uses
st_mode in one place but only to check for symlinks.  I could maybe have 
a fast mtime
if check_symlink_flag is not set, in that case only the file time is 
used.  One issue is that
FILE_TIMESTAMP is a uintmax_t and the windows call uses __int64 for the 
time stamp.

-Bill