[LLVMdev] making a copy of a byval aggregate on the callee's frame

Tim Northover t.p.northover at gmail.com
Fri Jul 5 03:45:57 PDT 2013

> What I should have said is that the new pointer is used by the callee rather than the original byVal pointer arg.

Probably, I thought it looked a bit odd. Your code sequence looks
reasonable (apart from byval still being present in the argument list;
as you said before, lowering should probably remove that).

> Also, LowerFormalArguments() is not that late!

It's part of the LLVM IR to DAG conversion and target-specific. In
LLVM terms that is late. All of the opt passes have run by this point,
and they are the ones likely to make use of the extra freedom



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