[llvm-dev] GlobalISel design update and goals

[Leslie Zhai]

Hi Andrew,

Thanks for your teaching!


在 2018年08月13日 20:39, Andrew Haley 写道:
> On 08/03/2018 04:56 AM, Leslie Zhai wrote:
>> * There is no instruction selection "concept" equivalent to LLVM's
>> SelectionDAG and GlobalISel in HotSpot C1? Because I manually write
>> assembly[1] lowing HIR to LIR in HotSpot C1. So which one is better?
>> LLVM or HotSpot selection by human?
> The goal of C1 is to be simple and fast.  C2 does the pattern-matching
> instruction generation.
>
>> * Why not use Greedy, just like LLVM's RegAllocGreedy, to take place of
>> Linear Scan[2] for HotSpot C1's register allocation?
> Same reason as above.  Also, there will be very little popularity for major
> rewrites of C1.  It is what it is.
>

-- 
Regards,
Leslie Zhai