[llvm] [llvm][ARM][CodeGen] Disable MEMCPY LDM/STM inlining for Cortex v7-m (PR #106378)

[Nashe Mncube via llvm-commits]

nasherm wrote:

> This makes it sound like the issue isn't the performance of ldm/stm itself, but rather that the expansion of memcpy is using too many registers. It doesn't seem right to completely throw away the existing code because of that; it should be possible to adjust it to load/store fewer registers at a time (ldrd/strd).

That makes sense. I think going forward with this patch may not be ideal then. I'll investigate whether a change to how memcpys are expanded can give similar performance improvements. Closing this ticket for now

https://github.com/llvm/llvm-project/pull/106378