[PATCH] D153742: [RISCV] Add Zce extension.

Mon Jun 26 20:55:18 PDT 2023

craig.topper added a comment.

In D153742#4449694 <https://reviews.llvm.org/D153742#4449694>, @craig.topper wrote:

> In D153742#4449614 <https://reviews.llvm.org/D153742#4449614>, @asb wrote:
>
>> Looking at the PDF, the behaviour I feel is slightly unclear is for RV64 with F and with Zce. You've chosing in this patch to allow it but to just not include zcf, though by my first reading of the spec I probably would have errored on the basis that "Specifying Zce with F includes Zca, Zcb, Zcmp, Zcmt and Zcf" and Zcf on RV64 is of course illegal. I think we have some leeway in how we handle this, but do you happen to know if GCC does something similar?
>
> I don't know what gcc does. I tried godbolt with "compile to binary" enabled. binutils rejected all of the Zc* extensions.
>
> @Nelson1225 can you provide any information about what binutils does or will do?

I filed https://github.com/riscv/riscv-code-size-reduction/issues/221 to get this clarified.

Repository:
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  https://reviews.llvm.org/D153742/new/

https://reviews.llvm.org/D153742