Mail Archives: djgpp/1998/09/18/19:00:48
From: | elvenforst AT aol DOT com (ElvenForst)
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Newsgroups: | comp.os.msdos.djgpp
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Subject: | Allegro and Linux
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Lines: | 15
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NNTP-Posting-Host: | ladder01.news.aol.com
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Date: | 18 Sep 1998 22:52:28 GMT
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Organization: | AOL http://www.aol.com
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Message-ID: | <19980918185228.08730.00001225@ng-fc2.aol.com>
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To: | djgpp AT delorie DOT com
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DJ-Gateway: | from newsgroup comp.os.msdos.djgpp
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To all,
I have just about had it up to -here- with Windows, and it's time for me to
delete it off of my hard drive. I've done lots of work with Linux and I'm
thinking of installing it back on my computer. But, I don't want to give up
Allegro! Does Allegro work under Linux? I saw some Linux stuff in allegro.h
so I thought that is might, but I want to be SURE. I don't want to have to
re-write any of my software if it can be helped. Has anyone tried this?
Also, if I can do it, I'm developing software that will eventually be used in
DOS. Can I develop the software under Linux (and Allegro) and then be able to
compile it with DJGPP at a later point in time?
--Richard Ellwood
tmp = rcv();
if (tmp)
return (tmp);
tmp = x;
return (y - tmp);
}
"GCC -O2 -S test.c" (version 2.7.2.1) gave me the following:
_test:
pushl %ebp
movl %esp,%ebp
subl $4,%esp
pushl %ebx
movb 8(%ebp),%bl
movb 12(%ebp),%cl
movb %cl,-4(%ebp)
call _rcv
movl %eax,%edx
testl %edx,%edx
jne L2
movsbl %bl,%edx
movsbl -4(%ebp),%eax
subl %edx,%eax
jmp L3
.align 2,0x90
L2:
movl %edx,%eax
L3:
movl -8(%ebp),%ebx
leave
ret
What happened? I really did have the "-O2". I can make tiny
changes in the above code and suddenly get decent output. What
about the above code makes the optimizer go insane?
BTW: I also tried -fomit-frame-pointer on my live code and it
doesn't help. I guess I misunderstood the documentation. I
thought it meant it omitted the frame pointer based on some
cutoff for how much it was used. In my code it omitted it
always, which makes most routines slightly better and some
routines very much worse.
--
http://www.erols.com/johnfine/
http://www.geocities.com/SiliconValley/Peaks/8600/
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