[PATCH] D157836: [RFC][IR] Correct lowering of `f128` intrinsics

Mon Aug 14 18:26:41 PDT 2023

pengfei added a comment.

In D157836#4587066 <https://reviews.llvm.org/D157836#4587066>, @tmgross wrote:

> In D157836#4586676 <https://reviews.llvm.org/D157836#4586676>, @efriedma wrote:
>
>> clang knows the layout of "long double", but we don't explicitly pass it down to LLVM.  I don't think it's something we've ever needed to care about; e.g. compiler-rt routines use different names for f80 vs. f128.
>>
>> Not sure exactly what the design of that would look like off the top of my head; maybe something involving a module flag.
>
> It seems like this logic needs to move from clang to LLVM since this affects non-C codegen, correct? This could probably travel with target information, I assume clang can pull this from llvm where needed.
>
> I can probably figure out the work for this but just need a rough outline of what the changes will look like.

You may override it in `X86ISelLowering.cpp`, see the line starting from `Setup Windows compiler runtime calls.`

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D157836/new/

https://reviews.llvm.org/D157836