Displaying 3 results from an estimated 3 matches for "usefp".
2020 Oct 08
2
GlobalISel round table follow up: register bank select
...cause yes for
> this particular use we are inserting costly cross copies, but there
> are no guarantees that replacing the mapping of the definition will
> not insert even more costly copies for the other uses.
>
> E.g., consider:
> ```
> A = def <— RBS starts here
> = useFP A
> = useInt A
> = useInt A
> ```
>
> Let’s assume that greedy works the way it is intended. I.e., it
> assigns A to the int register bank because there are 2 such uses vs.
> only 1 fp bank use:
> ```
> A<int> = def
> = useFP A<int> <— Next, RBS looks...
2020 Oct 07
2
GlobalISel round table follow up: register bank select
Hi all,
this is the second email for the round table follow-up, this time
regarding the issues around the greedy RegBankSelect and alternative
mappings.
The issue I brought up was that because RegBankSelect goes top-down, it
never looks at all available mappings for the operands when considering
which of the mappings to apply to the current instruction. In our
architecture we have one
2020 Oct 09
2
GlobalISel round table follow up: register bank select
...costly cross copies, but
>>> there are no guarantees that replacing the mapping of the definition
>>> will not insert even more costly copies for the other uses.
>>>
>>> E.g., consider:
>>> ```
>>> A = def <— RBS starts here
>>> = useFP A
>>> = useInt A
>>> = useInt A
>>> ```
>>>
>>> Let’s assume that greedy works the way it is intended. I.e., it
>>> assigns A to the int register bank because there are 2 such uses vs.
>>> only 1 fp bank use:
>>> ```
>>...