Re: [Qemu-devel] Help with softfloat.c code

[Programmingkid]

> On Sep 17, 2018, at 2:51 PM, Peter Maydell <address@hidden> wrote:
> 
> On 17 September 2018 at 18:56, Programmingkid <address@hidden> wrote:
>> 
>>> On Sep 17, 2018, at 1:52 PM, Peter Maydell <address@hidden> wrote:
>>> 
>>> On 17 September 2018 at 18:48, Programmingkid <address@hidden> wrote:
>>>> What I hope to do is implement a PowerPC CPU flag that indicates if an 
>>>> rounded result is inexact.
>>> 
>>> How is this different from the float_flag_inexact flag that softfloat 
>>> already
>>> supports ?
>> 
>> Sorry I meant to say if a rounded result is different from the intermediate 
>> result. This is what the FPSCR[FR] flag indicates on the PowerPC.
> 
> Looking at the PPC spec that seems to be "inexact but not overflow" so you
> should be able to calculate it via suitable handling of our existing
> float flags.

So if an inexact exception takes place without the overflow bit set, it means 
the fraction rounded bit should be set? I don't believe that would work for 
PowerPC.