Hi Jim,
It’s best to email llvmdev with general questions, as I get swamped and backlogged frequently. We don’t have a good answer at present to the problem above, but I have some thoughts on the matter here:
http://nondot.org/sabre/LLVMNotes/MemoryUseMarkers.txt
We do currently have a hack in the inliner to reuse stack array memory that are inlined from different callees into a common caller.
-Chris