diff options
Diffstat (limited to 'llvm/include/llvm/Support/GenericDomTree.h')
| -rw-r--r-- | llvm/include/llvm/Support/GenericDomTree.h | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/llvm/include/llvm/Support/GenericDomTree.h b/llvm/include/llvm/Support/GenericDomTree.h index 8e5e4123002..6f9a6805f4f 100644 --- a/llvm/include/llvm/Support/GenericDomTree.h +++ b/llvm/include/llvm/Support/GenericDomTree.h @@ -481,11 +481,15 @@ class DominatorTreeBase { /// Inform the dominator tree about a CFG edge deletion and update the tree. /// - /// This function has to be called just after making the update - /// on the actual CFG. There cannot be any other updates that the dominator - /// tree doesn't know about. The only exception is when the deletion that the - /// tree is informed about makes some (dominator) subtree unreachable -- in - /// this case, it is fine to perform deletions within this subtree. + /// This function has to be called just after making the update on the actual + /// CFG. An internal functions checks if the edge doesn't exist in the CFG in + /// DEBUG mode. There cannot be any other updates that the + /// dominator tree doesn't know about. + /// + /// However, it is fine to perform multiple CFG deletions that make different + /// subtrees forward-unreachable and to inform the DomTree about them all at + /// the same time, as the incremental algorithm doesn't walk the tree above + /// the NearestCommonDominator of a deleted edge /// /// Note that for postdominators it automatically takes care of deleting /// a reverse edge internally (so there's no need to swap the parameters). |
