[clang] [llvm] [LLVMABI] Implement the System V X86-64 ABI (PR #194718)

[Nikita Popov via cfe-commits]

nikic wrote:

When forcing on the use of the ABI library, there are a few test failures, e.g. clang/test/CodeGen/complex-libcalls.c. (I force enabled by commenting out the `if (!CodeGenOpts.ExperimentalABILowering)` check, because I couldn't figure out how to change the default in a way that actually works...)

I'm also experimenting with comparing the results between Clang and the ABI library again, currently with this patch: https://gist.github.com/nikic/7fd434e8b427a58ed532cc3a3b19c9b1 It only checks that the Kind is the same. I'll create a PR for the validation when I have time to finish it.

This also throws up some issues, e.g. for the test clang/test/CodeGen/X86/avx-cxx-record.cpp:

> For return value of type struct XMM2: Kind mismatch (expected: Direct, given: Indirect)


https://github.com/llvm/llvm-project/pull/194718