From: "Steve Snyder" <swsnyder AT home DOT com>
To: "pgcc AT delorie DOT com" <pgcc AT delorie DOT com>
Date: Tue, 22 Jun 1999 08:20:29 -0400 (EST)
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Subject: Re: pgcc does better, reboot, then does terrible!(SOLVED)
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On Tue, 22 Jun 1999 03:11:18 -0500, Jon wrote:

>If I use egcs for some reason -mcpu=pentiumpro -march=pentiumpro work! 
>-mstack-align-double doesn't, the compiler complains.  What works with
>egcs1.1.2 is:
>
>CFLAGS = -Wall -mpentium -mcpu=pentiumpro -march=pentiumpro -O4
>-malign-loops=2 -malign-jumps=2 -malign-functions=2 -malign-double
>--fast-math -pg

I'm a little puzzled by your use of some of these switches.

1. Why use -mpentium, then turn around use -mcpu=pentiumpro?  Doesn't the 
latter switch make the former redundant?

2. Why use -O4 in preference to -O6?

3. Why specify the loop/jump/function alignment with the default values? 
According to the egcs doc, you should get this same alignment even if you 
dispense with the -malign-* switches entirely.

4. How safe is the -malign-double switch?  The egcs doc contains a (to me) 
scary warning about breaking compatibility with "the published application 
binary interface for the 386".  Is it your experience that this is not a 
real problem?

Thank you.


*** Steve Snyder ***