[PATCH] D42509: [LivePhysRegs] Preserve pristine registers in blocks with no successors.

[Krzysztof Parzyszek via Phabricator via llvm-commits]

kparzysz added a comment.

In https://reviews.llvm.org/D42509#987226, @MatzeB wrote:

> A noreturn call doesn't need to have the callers callee saved registers restored.


Why not?  The non-returning call doesn't come back to its call site, but it goes somewhere. From the point of view of some function foo, all of that activity may happen inside the call to bar (which would have further calls in it). Not preserving non-volatile registers could cause them to end up being clobbered across the call to bar.


Repository:
  rL LLVM

https://reviews.llvm.org/D42509