On Tue, Aug 22, 2017 at 3:28 PM, Pekka Jääskeläinen wrote:
> Hi Richard and Joseph,
>
> Replies for both inline:
>
> I wrote:
>>> Both the inputs and outputs must be flushed to zero in the HSAIL’s
>>> ‘ftz’ semantics.
>>> FTZ operations were previously always “explicit” in the BRIG FE output,
>>>
Hi Richard and Joseph,
Replies for both inline:
I wrote:
>> Both the inputs and outputs must be flushed to zero in the HSAIL’s
>> ‘ftz’ semantics.
>> FTZ operations were previously always “explicit” in the BRIG FE output, like
>> you
>> propose here; there were builtin calls injected for all inp
On Mon, 14 Aug 2017, Pekka Jääskeläinen wrote:
> Both the inputs and outputs must be flushed to zero in the HSAIL’s
> ‘ftz’ semantics.
Presumably this means that constant folding needs to know about those
semantics, both for operations with a subnormal floating-point argument
(whether or not th
On Mon, Aug 14, 2017 at 12:45 PM, Pekka Jääskeläinen wrote:
> Hi Richard,
>
> The base idea of the patch is to optimize for the (common) situation
> where FTZ/DAZ
> is controlled by a CPU-wide flag and we then need to only avoid compile-time
> optimizations that assume semantics where denorm handl
Hi Richard,
The base idea of the patch is to optimize for the (common) situation
where FTZ/DAZ
is controlled by a CPU-wide flag and we then need to only avoid compile-time
optimizations that assume semantics where denorm handling is on to support
the ‘forced FTZ/DAZ semantics’.
> This suggests on
On Thu, Aug 10, 2017 at 6:39 PM, Pekka Jääskeläinen wrote:
> Hi,
>
> The attached patch adds a new switch -fftz-math which makes certain
> optimizations
> assume that "flush to zero" behavior of denormal inputs and outputs is
> not an optimization
> hint, but required behavior for semantical corre
Hi,
The attached patch adds a new switch -fftz-math which makes certain
optimizations
assume that "flush to zero" behavior of denormal inputs and outputs is
not an optimization
hint, but required behavior for semantical correctness.
The need for this was initiated by HSAIL (BRIG). With HSAIL, flu
