From 56362c4e5ba71aa454faff08df75b5dca618ab1c Mon Sep 17 00:00:00 2001 From: Matthias Braun Date: Mon, 16 Feb 2015 19:34:27 +0000 Subject: [PATCH] RegisterCoalescer: Improve previous fix for wrong def after. The previous fix in r225503 was needlessly complicated. The problem goes away as well if the arguments to MergeValueNumberInto are supplied in the correct order. This was previously missed because the existing code already had the wrong order but an additional later Merge was hiding the bug for the main liverange VNI. llvm-svn: 229424 --- lib/CodeGen/RegisterCoalescer.cpp | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/lib/CodeGen/RegisterCoalescer.cpp b/lib/CodeGen/RegisterCoalescer.cpp index 5cc11ae0309..65b0e5026f0 100644 --- a/lib/CodeGen/RegisterCoalescer.cpp +++ b/lib/CodeGen/RegisterCoalescer.cpp @@ -738,15 +738,14 @@ bool RegisterCoalescer::removeCopyByCommutingDef(const CoalescerPair &CP, continue; DEBUG(dbgs() << "\t\tnoop: " << DefIdx << '\t' << *UseMI); assert(DVNI->def == DefIdx); - BValNo = IntB.MergeValueNumberInto(BValNo, DVNI); + BValNo = IntB.MergeValueNumberInto(DVNI, BValNo); for (LiveInterval::SubRange &S : IntB.subranges()) { VNInfo *SubDVNI = S.getVNInfoAt(DefIdx); if (!SubDVNI) continue; VNInfo *SubBValNo = S.getVNInfoAt(CopyIdx); assert(SubBValNo->def == CopyIdx); - VNInfo *Merged = S.MergeValueNumberInto(SubBValNo, SubDVNI); - Merged->def = CopyIdx; + S.MergeValueNumberInto(SubDVNI, SubBValNo); } ErasedInstrs.insert(UseMI);