Date: Wed, 14 Jun 2000 09:10:03 -0700 (PDT) From: mi@privatelabs.com To: freebsd-bugs@FreeBSD.org Subject: Re: i386/19245: -fexpensive-optimizations buggy (even with -O) Message-ID: <200006141610.JAA87811@freefall.freebsd.org>
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The following reply was made to PR i386/19245; it has been noted by GNATS. From: mi@privatelabs.com To: Bruce Evans <bde@zeta.org.au> Cc: FreeBSD-gnats-submit@FreeBSD.ORG Subject: Re: i386/19245: -fexpensive-optimizations buggy (even with -O) Date: Wed, 14 Jun 2000 12:08:17 -0400 (EDT) On 14 Jun, Bruce Evans wrote: = > The attached piece of code, when compiled with ``-O = > -fexpensive-optimizations'', produces incorrect binary on = > FreeBSD-4.0. = > = > I tested the same compiler line on Mandrake Linux (an identical = > machine hardware-wise) and it compiles correctly. = = This is hard to explain, since the bug shown by your example is in gcc = (2.95.2), not in the assembler or linker. Oh, I know so little... But I can give an interested party an account on the machine to verify this... May be, it the specs? AFAIK, the function calls are done differently on Linux -- could that be the reason (with gcc mostly developed on Linux (right?) -- they may not have cought all the bugs on other OSes)? = Don't use -O2 (which enables -fexpensive-optimizations) unless you = want to find bugs like this :-). That's the thing -- I only asked for -O but with the explicit -fexpensive-optimizations. Will -ON ever be reliable for N>1 ? -mi To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message
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