Displaying 7 results from an estimated 7 matches for "nocontraction".
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2018 Aug 23
2
Condition code in DAGCombiner::visitFADDForFMACombine?
Nicolai,
Can you do without the use of -fp-contract=fast (Options.AllowFPOpFusion == FPOpFusion::Fast ) and without Unsafe?
As I SPIR-V’s usage of NoContraction flies in the face of both.
If so, you should be able to get what you want, as then you are down to just IR flags. You will need a model to generate the correct behavior though in your SPIR-V implementation wrt IR flag emissions.
Regards,
Michael
> On Aug 23, 2018, at 1:35 PM, Nicolai Hähnle...
2018 Aug 23
3
Condition code in DAGCombiner::visitFADDForFMACombine?
I don't think the global fast math flag should override the NoContraction
decoration as that's mostly the point of that decoration to begin with, to
have fine granular control while still having a broad sweeping
optimization. Did I miss your point? I feel like I did.
On Thu, Aug 23, 2018, 3:42 PM Michael Berg <michael_c_berg at apple.com> wrote:
> Ryan,
&...
2018 Aug 23
2
Condition code in DAGCombiner::visitFADDForFMACombine?
Michael,
>From the spec with regards to reassoc:
– 15225 Include no re-association as a constraint required by the
NoContraction Decoration.
I don't see a solution given the situation where -fp-contract=fast and we
want to contract. Furthermore, I think a 'nocontract' flag will allow the
IR to be more readable in it's intention. The problem is you can have 2 fp
arith instructions with no contracts and no rea...
2018 Aug 23
2
Condition code in DAGCombiner::visitFADDForFMACombine?
...hings are supposed to work from the
> current description.
>
>
> On Wed, Aug 22, 2018 at 9:41 AM, Nicolai Hähnle via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
>> On 22.08.2018 13:29, Ryan Taylor wrote:
>>
>>> The example starts as SPIR-V with the NoContraction decoration flag on
>>> the fmul.
>>>
>>> I think what you are saying seems valid in that if the user had put the
>>> flag on the fadd instead of the fmul it would not contract and so in this
>>> example the user needs to put the NoContraction on the fadd...
2018 Aug 22
4
Condition code in DAGCombiner::visitFADDForFMACombine?
On 22.08.2018 13:29, Ryan Taylor wrote:
> The example starts as SPIR-V with the NoContraction decoration flag on
> the fmul.
>
> I think what you are saying seems valid in that if the user had put the
> flag on the fadd instead of the fmul it would not contract and so in
> this example the user needs to put the NoContraction on the fadd though
> I'm not sure that&...
2018 Aug 22
2
Condition code in DAGCombiner::visitFADDForFMACombine?
On 21.08.2018 16:08, Ryan Taylor via llvm-dev wrote:
> So I have a test case where:
>
> %20 = fmul nnan arcp float %15, %19
> %21 = fadd reassoc nnan arcp contract float %20, -1.000000e+00
>
> is being contracted in DAG to fmad. Is this correct since the fmul has
> no reassoc or contract fast math flag?
By having the reassoc and contract flags on fadd, the frontend is
2018 Aug 22
2
Condition code in DAGCombiner::visitFADDForFMACombine?
...he discussion (if one is needed).
Cheers,
Nicolai
>
> On Wed, Aug 22, 2018 at 11:41 AM Nicolai Hähnle <nhaehnle at gmail.com
> <mailto:nhaehnle at gmail.com>> wrote:
>
> On 22.08.2018 13:29, Ryan Taylor wrote:
> > The example starts as SPIR-V with the NoContraction decoration
> flag on
> > the fmul.
> >
> > I think what you are saying seems valid in that if the user had
> put the
> > flag on the fadd instead of the fmul it would not contract and so in
> > this example the user needs to put t...