On 27 September 2016 at 09:51, G 3 wrote:
> The problem with your reasoning is you assume this instruction has to be
> 100% correctly implemented. That every single "corner-case" has to be
> accounted for.
For upstream QEMU we've already made this design decision --
emulation accuracy comes first
On Sep 27, 2016, at 12:16 PM, Eric Blake wrote:
On 09/27/2016 09:33 AM, G 3 wrote:
void fmadds(float *frD, float frA, float frC, float frB)
{
*frD = frA * frC + frB;
}
It sounds like I should change my argument types to double.
Insufficient. The whole reason that fmadds exists i
On 09/27/2016 09:33 AM, G 3 wrote:
>>> void fmadds(float *frD, float frA, float frC, float frB)
>>> {
>>> *frD = frA * frC + frB;
>>> }
>
> It sounds like I should change my argument types to double.
Insufficient. The whole reason that fmadds exists is that there are
provably cases wher
On 27 September 2016 at 07:33, G 3 wrote:
>
> On Sep 27, 2016, at 7:43 AM, Peter Maydell wrote:
>> In particular, for fmadds, it is important that there
>> is no intermediate rounding done between the multiply
>> and the addition. This means that you need to effectively
>> do the multiply and the
On Sep 27, 2016, at 7:43 AM, Peter Maydell wrote:
On 26 September 2016 at 18:05, G 3 wrote:
I made my own experimental implementation of the fmadds
instruction that I
would like to add to QEMU. How would I do this?
My implementation would probably look like this:
void fmadds(float *frD, f
On 26 September 2016 at 18:05, G 3 wrote:
> I made my own experimental implementation of the fmadds instruction that I
> would like to add to QEMU. How would I do this?
>
> My implementation would probably look like this:
>
> void fmadds(float *frD, float frA, float frC, float frB)
> {
> *
I made my own experimental implementation of the fmadds instruction
that I would like to add to QEMU. How would I do this?
My implementation would probably look like this:
void fmadds(float *frD, float frA, float frC, float frB)
{
*frD = frA * frC + frB;
}
I then want to see if this
