Displaying 4 results from an estimated 4 matches for "visitsdiv".
2015 Aug 20
3
[RFC] Improving integer divide optimization (related to D12082)
...get the generic code to reach its custom hook?
>> Now the "cheap pow2 sdiv” is merged with the generic “cheap div” you can’t
>> distinguish anymore.
>>
>
> Yes and also the issue of needing more information to make a smart
> isIntDivCheap() decision.
>
> In visitSDIV(), checking looks like this when the denominator is a power of 2.
>
> if (TLI.isIntDivCheap(N->getValueType(0), MinSize))
> return SDValue();
>
> // Target-specific implementation of sdiv x, pow2.
> if (SDValue Res = BuildSDIVPow2(N))
> return Res;
>...
2015 Aug 20
2
[RFC] Improving integer divide optimization (related to D12082)
> On Aug 19, 2015, at 3:48 PM, escha via llvm-dev <llvm-dev at lists.llvm.org> wrote:
>
>
>> On Aug 19, 2015, at 1:45 PM, Steve King via llvm-dev <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote:
>>
>> In the targets I know, shifts are
>> cheaper than divides in both speed and size.
>
> From what I remember, udiv by
2015 Aug 20
2
[RFC] Improving integer divide optimization (related to D12082)
...Now the "cheap pow2 sdiv” is merged with the generic “cheap div” you can’t
>>>> distinguish anymore.
>>>>
>>>
>>> Yes and also the issue of needing more information to make a smart
>>> isIntDivCheap() decision.
>>>
>>> In visitSDIV(), checking looks like this when the denominator is a power of 2.
>>>
>>> if (TLI.isIntDivCheap(N->getValueType(0), MinSize))
>>> return SDValue();
>>>
>>> // Target-specific implementation of sdiv x, pow2.
>>> if (SDValue Res = B...
2020 Mar 27
2
Instruction selection phase
Hello LLVM-Dev,
Attached are:
· The DAG after being built
· The DAG before the legalization phase
The DAG illustrated performs a signed division for type i32. As can be seen, the SDIV node was converted to a series of other nodes (which includes a MULHS node). In the target lowering class of our target, the SDIV has an operation action of custom. Does anybody know where in