[llvm] [AArch64] Copy MMO in ld1 / st1 post index selection. (PR #199023)

[David Green via llvm-commits]

davemgreen wrote:

> > While the pointer arguments dst and src are qualified with **restrict**, standard compiler memory model rules dictate that **restrict** allows assuming two pointers do not alias unless physical program flow establishes a direct address overlap within the same execution block.
> 
> I have never heard about that part staring with "unless physical program flow ...". Any references ?

I hadn't read that, but I'm not sure it matters in this case. This version prints the ptrs https://godbolt.org/z/3EdWEbzxE and it sees:
dst:b74cce379640 src:b74cce379644 diff:-4 count:98
in CopyUnaligned, which would then load + store larger chunks than 4 (16 for vectors), let alone the whole range of 98 * 4.


https://github.com/llvm/llvm-project/pull/199023