tree 401001fdf03f243858333135ff77f3d73a69031a
parent b9a7bea99c8aac6eb3509df93a25fe9cc3858bde
author Devang Patel <dpatel@apple.com> 1173143176 +0000
committer Devang Patel <dpatel@apple.com> 1173143176 +0000

Add preparePassManager() hook. This allows each pass to check whether
current active pass manager is appropriate or not.

A loop pass may consider current LPPassManager in appropraite if loop
pass is not preserving analysis information that is used by other
passes managed by current LPPassManager. In such situation, loop pass
can pop current LPPassManager from the PMStack using this  hook
and use new LPPassManager for itself.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34941 91177308-0d34-0410-b5e6-96231b3b80d8