From a6b1926531b78f5fa45503aebea30cdb616114b7 Mon Sep 17 00:00:00 2001 From: Owen Anderson Date: Mon, 21 Jan 2008 22:03:00 +0000 Subject: [PATCH] Clarify a deviation from the original algorithm. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46218 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/StrongPHIElimination.cpp | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/lib/CodeGen/StrongPHIElimination.cpp b/lib/CodeGen/StrongPHIElimination.cpp index ff58e796bf5..5b80b94f3fc 100644 --- a/lib/CodeGen/StrongPHIElimination.cpp +++ b/lib/CodeGen/StrongPHIElimination.cpp @@ -552,7 +552,10 @@ void StrongPHIElimination::processPHIUnion(MachineInstr* Inst, DomForestNode* child = *CI; // If the current node is live-out of the defining block of one of its - // children, insert a copy for it + // children, insert a copy for it. NOTE: The paper actually calls for + // a more elaborate heuristic for determining whether to insert copies + // for the child or the parent. In the interest of simplicity, we're + // just always choosing the parent. if (isLiveOut(DFNode->getReg(), MRI.getVRegDef(child->getReg())->getParent(), MRI, LV)) { // Insert copies for parent -- 2.34.1