[llvm] [SLP]Initial support for copyable elements (non-schedulable only) (PR #140279)

[Hans Wennborg via llvm-commits]

zmodem wrote:

> even with the debug version of the compiler it passed fast.

But it asserts in the backend, right?

"Invalid SubReg for physical register" does sound like a backend problem. Could it be caused by the vectorizer somehow generating bad IR, or do you think it just uncovered a pre-existing backend bug?

https://github.com/llvm/llvm-project/pull/140279