[PATCH] D52895: [TailCallElim] Enable marking of calls with byval as tails

[Reid Kleckner via Phabricator via llvm-commits]

rnk added a comment.

Nice!

In https://reviews.llvm.org/D52895#1255602, @nicholas wrote:

> I don't understand the logical model behind byval, but I'll review the change to TRE under the assumption that the goal of the patch is correct.


You have to hallucinate an implicit memcpy into the call sequence. Its destination is some stack memory allocated during the call sequence not visible from LLVM IR.



================
Comment at: test/Transforms/Inline/byval-tail-call.ll:63
+  ret void
+}
----------------
I'd throw in a test case where %x is a local alloca, since that should also work.


Repository:
  rL LLVM

https://reviews.llvm.org/D52895