Gentoo Archives: gentoo-amd64

From: Alex Schuster <wonko@×××××××××.org>
To: gentoo-amd64@l.g.o
Subject: Re: [gentoo-amd64] GCC-4.5.2 Has Serious Problems
Date: Thu, 30 Jun 2011 22:32:15
In Reply to: [gentoo-amd64] GCC-4.5.2 Has Serious Problems by Frank Peters
Frank Peters writes:

> After banging my head for a while over some strange results, I began > to suspect GCC-4.5.2, the latest version in portage, was creating > faulty code. > > It seems to a correct suspicion.
> The problem can be fixed by compiling the program with "O1" > optimization:
Or -O3.
> For anyone who wants to try to duplicate these results, please feel > free to do so. > > So I will have to conclude that GCC-4.5.2 has serious problems. > This kind of erroneous behavior could appear anywhere.
Oh dear, that's scary. I can confirm this. With -O0, -O1 and -O3, all is fine. -O2 gives the result you see. And with -Os, I get yet another result (0/0, 4/4, 8/8). This is an AMD Athlon(tm) Dual Core Processor 4850e, gcc has been copmpiled with these use flags: fortran gtk mudflap multilib nls nptl openmp Who will file the bug report now? Wonko


Subject Author
Re: [gentoo-amd64] GCC-4.5.2 Has Serious Problems Frank Peters <frank.peters@×××××××.net>