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Re: -fomit-frame-pointer


Christopher Faylor wrote:
> 
> On Thu, Feb 01, 2001 at 12:19:52AM -0600, Mumit Khan wrote:
> >On Wed, 31 Jan 2001, Christopher Faylor wrote:
> >
> >> Anybody ever tried building cygwin with -fomit-frame-pointer optimization?
> >> It sort of works if you choose the files that you compile with this option
> >> carefully.
> >
> >Last time I tried was a while back, and I ended up with a non-working DLL.
> >However, it was a long time ago, and it's probably time to try it again.
> >My next build, right after I get the patches in for gcc-2.97 build  ...
> 
> You can't compile every file like this or you'll screw up signal handling
> badly, but it seems to work on selected files.  I wonder if it is worth
> using this option on some files or if the maintenance won't be worth it.
> 

I've not tried that optimization yet but I do use and have CFLAGS and
CXXFLAGS set to:

-O3 -s -fnative-struct -foptimize-register-move -fgnu-linker -ffast-math
-fnew-exceptions -frerun-loop-opt -frerun-cse-after-loop -fgcse
-fpeephole -fstrength-reduce -fthread-jumps -fexpensive-optimizations
-fvolatile -mpreferred-stack-boundary=8 -march=i686

The preferred-stack-boundary=8 does produce a slightly larger dll but
not that much and I think it's worth it.  You probably wouldn't want to
net release a -march=i686 unless you also release a -march=i386.

YMMV,
Earnie.

P.S.: I already know that some of the switches listed may be already
added with the -O3 switch but I haven't taken the time to discover which
ones.

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