The MemorySSA-based implementation has been enabled for a few months
(since D94376). This patch drops the old MDA-based implementation
entirely.
I've kept this to only the basic cleanup of dropping various
conditions -- the code could be further cleaned up now that there
is only one implementation.
Differential Revision: https://reviews.llvm.org/D102113
This adds an -enable-memcpyopt-memoryssa option that currently does
nothing apart from requiring MSSA as a dependency. The tests are
split to run both with the option disabled and enabled. I went with
this rather than the separate directory DSE uses, as I found it
convenient to have a direct side-by-side comparison of differences.
Differential Revision: https://reviews.llvm.org/D89206
If we allow the non-integral pointers to become memset and memcpy, we loose the ability to reason about pointer propagation. This patch is modeled on changes we've carried downstream for a long time, figured it was worth being equally conservative for other users. There is room to refine the semantics and handling here if anyone is motivated.
Nikita Popov