[clang] [llvm] [clang][X86] Return Win64 __int128 indirectly (PR #210358)

[via llvm-commits]

Andarwinux wrote:

> 07:39 <lh_mouse> returning `__int128` in XMM0 looks silly; it requires moving high and low parts of the value from integer registers into an SSE register, which is not trivial.

https://godbolt.org/z/Mvx45Tvco

That's just incredibly stupid. Does this guy really think memory access is cheaper than vmovq+vpunpcklqdq/vpextrq?

https://github.com/llvm/llvm-project/pull/210358