[PATCH] D53291: add riscv32e to the llvm

[James Clarke via Phabricator via llvm-commits]

jrtc27 added a comment.
Herald added a subscriber: nhaehnle.

In https://reviews.llvm.org/D53291#1266207, @xudaliang.pku wrote:

> In https://reviews.llvm.org/D53291#1266088, @asb wrote:
>
> > Hi Daliang and welcome to the LLVM community.
> >
> > Many thanks for your work on RV32E support. In our discussion on the sw-dev mailing list I suggested <https://groups.google.com/a/groups.riscv.org/d/msg/sw-dev/EEd3xSUXcfg/DgeswrTMFQAJ> splitting this task into the MC layer, calling convention, and codegen support. I'd recommend preparing patches in a way that does this. Each of these elements should come along with tests.
> >
> > You shouldn't need to have riscv32e as a new triple. Just rely on the SubtargetFeature - this should remove a lot of code from this patch.
>
>
> I will spilt the patch later as you said. It is the first time I have upload my patch. So, maybe I consider too little about how to show my work.I will do better next time.
>  Just like you and  kito-cheng @kito-cheng have said. I had not added the  triple:riscv32e  in my work until I found clang-side needed to use that triple:riscv32e in the discussion on the sw-dev mailing list. The code in clang is like that
>
>   class RISCVABIInfo : public DefaultABIInfo {
>   private:
>     unsigned XLen; // Size of the integer ('x') registers in bits.
>     static const int NumArgGPRs = 8;
>  
>   public:
>     RISCVABIInfo(CodeGen::CodeGenTypes &CGT, unsigned XLen)
>         : DefaultABIInfo(CGT), XLen(XLen) { }
>   };
>
>
> Because the RISCVABIInfo can't get the SubtargetFeatures, NumArgGPRs will always be 8 int the RISCVABIInfo even if the march=rv32e. So I have no way except for adding the triple:riscv32e. you can also see what I have changed the clang in https://reviews.llvm.org/D53293 about How I changed the  NumArgGPRs by using triple:target. I was very confused how to solve this problem.Maybe a better way later.


The `RISCVABIInfo` constructor is called by `RISCVTargetCodeGenInfo`'s constructor, which in turn is called by `CodeGenModule::getTargetCodeGenInfo`. `CodeGenModule` has a `getTarget()` which should give you access to the feature flags?


Repository:
  rL LLVM

https://reviews.llvm.org/D53291