From 9ad136c851e0a66eb471573aac9fec47d53a61ba Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Wed, 21 Jan 2009 20:50:09 +0000 Subject: [PATCH] Add a comment to SelectionDAG::ReplaceAllUsesWith to describe a subtle iteraction with SelectionDAG CSE. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62713 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/CodeGen/SelectionDAG.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/include/llvm/CodeGen/SelectionDAG.h b/include/llvm/CodeGen/SelectionDAG.h index d7802d3cde6..f93b6207b8f 100644 --- a/include/llvm/CodeGen/SelectionDAG.h +++ b/include/llvm/CodeGen/SelectionDAG.h @@ -680,6 +680,11 @@ public: /// informed about nodes that are deleted and modified due to recursive /// changes in the dag. /// + /// These functions only replace all existing uses. It's possible that as + /// these replacements are being performed, CSE may cause the From node + /// to be given new uses. These new uses of From are left in place, and + /// not automatically transfered to To. + /// void ReplaceAllUsesWith(SDValue From, SDValue Op, DAGUpdateListener *UpdateListener = 0); void ReplaceAllUsesWith(SDNode *From, SDNode *To, -- 2.34.1