[PATCH] D87844: [CodeGen] Fixing inconsistent ABI mangling of vlaues in SelectionDAGBuilder

Thu Sep 17 11:21:09 PDT 2020

arsenm added a comment.

In D87844#2279854 <https://reviews.llvm.org/D87844#2279854>, @efriedma wrote:

> If I'm following this correctly, with this change, getABIRegCopyCC has one remaining caller, and that call always returns None.  So getABIRegCopyCC is useless, and the CallConv member of RegsForValue is always None?  It seems weird that all this code got built up around a useless operation, but I guess that sort of thing can happen.
>
> @arsenm Do you remember why you added getABIRegCopyCC in the first place?

It's because the value types used differ if the copy is in an ABI context, or just to get copyable values. e.g. a phi is not an ABI context, but getRegisterTypeForCallingConv/getNumRegistersForCallingConv may be different from the legal register types used for the value

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D87844/new/

https://reviews.llvm.org/D87844