Re: [Qemu-devel] [PATCH] Fix NaN handling in softfloat

[Aurelien Jarno <aurelien@aurel32.net>]

Daniel Jacobowitz a écrit :
> On Sat, Nov 03, 2007 at 06:35:48PM +0100, Aurelien Jarno wrote:
>> Hi all,
>>
>> The current softfloat implementation changes qNaN into sNaN when 
>> converting between formats, for no reason. The attached patch fixes
>> that. It also fixes an off-by-one in the extended double precision
>> format (aka floatx80), the mantissa is 64-bit long and not 63-bit
>> long.
>>
>> With this patch applied all the glibc 2.7 floating point tests
>> are successfull on MIPS and MIPSEL.
> 
> FYI, I posted a similar patch and haven't had time to get back to it.
> Andreas reminded me that we need to make sure at least one mantissa
> bit is set.  If we're confident that the common NaN format will
> already have some bit other than the qnan/snan bit set, this is fine;
> otherwise, we might want to forcibly set some other mantissa bit.
> 

Good point. I will try to improve my patch.

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