[llvm-branch-commits] [llvm] [RISCV] Add initial support of memcmp expansion (PR #107548)

[Pengcheng Wang via llvm-branch-commits]

wangpc-pp wrote:

> > > > Can we break the enabling down into more manageable pieces? I think `enableUnalignedScalarMem() && (Subtarget->hasStdExtZbb() || Subtarget->hasStdExtZbkb() || IsZeroCmp)` might be a good starting point.
> > > 
> > > 
> > > I'd be fine with this type of approach.
> > 
> > 
> > Thanks! I have applied this suggestion. For `ExpandMemcmp` issue, I will try to fix it later.
> 
> I meant we should start with only doing inline memcmp expansion under those conditions. Not just the overlapping loads part. The miscounting of loads that get split needs to be fixed before we can enable expansion without enableUnalignedScalarMem().

Oops, sorry I misunderstood it. Done.

https://github.com/llvm/llvm-project/pull/107548