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From: davidastro <davidastro@hotmail.com>
To: linuxppc-dev@ozlabs.org
Subject: Fix for __div64_32 locks when using some 64 bit numbers
Date: Tue, 17 Mar 2009 14:15:29 -0700 (PDT)	[thread overview]
Message-ID: <22567864.post@talk.nabble.com> (raw)


I found a bug when using the function __div64_32 in assembly in a 32 bit ppc
architecture unit.

I tried the numbers 55834565048000000 for the dividend and 4294967079 for
the divisor. When passing these two numbers to the function  __div64_32, I
had a software lock. I searched for possible patches online and in different
forums but I could not find anything related to the assembly implementation
to this function (I would have to apologize if somebody already found a fix
:-) ).

Anyway, when analyzing the assembly code, I found out with gdb the problem.
I am not an expert in ppc architecture but I read the documentation and I am
pretty sure I solved the issue (I have been testing for couple of days using
random 64 to 32 number combinations with good results).

Who or Where should I post the fix to be reviewed.

Thanks for your attention
-- 
View this message in context: http://www.nabble.com/Fix-for-__div64_32-locks-when-using-some-64-bit-numbers-tp22567864p22567864.html
Sent from the linuxppc-dev mailing list archive at Nabble.com.

             reply	other threads:[~2009-03-17 21:15 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-03-17 21:15 davidastro [this message]
2009-03-17 23:03 ` Fix for __div64_32 locks when using some 64 bit numbers Benjamin Herrenschmidt
2009-03-18 15:33   ` davidastro
2009-03-23  4:39     ` Paul Mackerras
2009-03-23 17:56       ` davidastro
2009-03-20 19:33   ` davidastro
2009-03-21 21:46     ` Benjamin Herrenschmidt

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