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Re: Incorrect code from EGCS-1.1 on PowerPC
- To: Gary Thomas <gdt at linuxppc dot org>
- Subject: Re: Incorrect code from EGCS-1.1 on PowerPC
- From: Jeffrey A Law <law at cygnus dot com>
- Date: Thu, 20 Aug 1998 01:06:46 -0600
- cc: egcs-bugs at cygnus dot com, Michal Jaegermann <michal at ellpspace dot math dot ualberta dot ca>
- Reply-To: law at cygnus dot com
In message <XFMail.980818151402.gdt@linuxppc.org>you write:
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> The attached code snippet (from the Linux kernel) generates incorrect
> code when compiled on Linux/PPC with "-O2" options.
>
> The problem stems from inlined functions and a pointer (skb) being
> dereferenced (skb->sb) before it is tested for NULL as a result of
> the loop being reorganized.
I just looked at the debugging dumps for this one. It was definitely
the haifa-sched.c change that fixed this problem. Amazing. I wonder
if this is the same problem that Michal has been having (he's seeing
problems in tcp_close_pending, but on the Alpha).
If I had known this particular bug in haifa was causing these problems
I would have encouraged Catherine to nail it down quicker. The good
news is we do have a testcase for this bug in the testsuite (980506-1.c)
jeff