From: Dan Gohman <gohman@apple.com>
Date: Tue, 11 Aug 2009 15:50:56 +0000 (+0000)
Subject: Add a comment about the additional meaning of setPreservesCFG() for
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=d1ad72f54f4abf62a5f0b2c297edf5e4b1ab1024;p=oota-llvm.git

Add a comment about the additional meaning of setPreservesCFG() for
MachineFunctionPass passes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78669 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/llvm/CodeGen/MachineFunctionPass.h b/include/llvm/CodeGen/MachineFunctionPass.h
index 6f7c216382a..60460afae7a 100644
--- a/include/llvm/CodeGen/MachineFunctionPass.h
+++ b/include/llvm/CodeGen/MachineFunctionPass.h
@@ -40,6 +40,10 @@ protected:
 
   /// getAnalysisUsage - Subclasses that override getAnalysisUsage
   /// must call this.
+  ///
+  /// For MachineFunctionPasses, calling AU.preservesCFG() indicates that
+  /// the pass does not modify the MachineBasicBlock CFG.
+  ///
   virtual void getAnalysisUsage(AnalysisUsage &AU) const;
 
 private: