[compiler-rt] [libc] [libcxx] [clang] [llvm] [clang-tools-extra] [flang] [RISCV][MC] Add support for experimental Zimop extension (PR #75182)

[Craig Topper via cfe-commits]

topperc wrote:

> > > @topperc If I am not mistaken Zicfiss extension uses moprr instructions to get ROP functionality. But Zimop does not limit only the use of Zicfiss extension. They can be redefined and assigned other operations.
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> > 
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> > Right, but won't users be programming to each of the extensions that redefine them rather than some generic interface? We don't have builtins/intrinsics for all of the HINT encodings that can redefined.
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> Yeah, I agree with you. 
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> But can be cases when someone in some narrow case needs to program logic by hand. Why restrict it? 
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> I also think that a generic interface is much better than achieving the same logic through builtins/intrinsics.

I just read back over my original question. I'm not sure it was clear that I was asking about the need for intrinsics. I don't object to assembler support and inline assembly is always an option.

https://github.com/llvm/llvm-project/pull/75182