[llvm] [AArch64] Generate DOT instructions from matching IR (PR #69583)

[via llvm-commits]

ktkachov-arm wrote:

Nice! I think this could also be easily extended to recognise the sign-changing SUDOT and USDOT variants from Armv8.6-a
https://developer.arm.com/documentation/ddi0596/2021-03/SVE-Instructions/SUDOT--Signed-by-unsigned-integer-indexed-dot-product-?lang=en
https://developer.arm.com/documentation/ddi0596/2021-03/SVE-Instructions/USDOT--vectors---Unsigned-by-signed-integer-dot-product-?lang=en

https://github.com/llvm/llvm-project/pull/69583