[PATCH] D38474: Add support for multiple prof metadata on instructions.

[Hiroshi Yamauchi via Phabricator via llvm-commits]

yamauchi added a comment.

In https://reviews.llvm.org/D38474#890672, @davidxl wrote:

> This does not look like backward compatible IR change.  For the purpose of annotating irreducible loop headers, it might be better to introduce a new type of metadata.


The current single-level format is still used when there's only one prof metadata per instruction. The two-level format is used only when there are multiple items.

So, it should be backward compatible in that sense at least.


https://reviews.llvm.org/D38474