diff options
| -rw-r--r-- | llvm/lib/CodeGen/RegisterCoalescer.cpp | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/llvm/lib/CodeGen/RegisterCoalescer.cpp b/llvm/lib/CodeGen/RegisterCoalescer.cpp index 5c5f8dc528c..cad13a60efd 100644 --- a/llvm/lib/CodeGen/RegisterCoalescer.cpp +++ b/llvm/lib/CodeGen/RegisterCoalescer.cpp @@ -2280,7 +2280,8 @@ std::pair<const VNInfo*, unsigned> JoinVals::followCopyChain( LiveQueryResult LRQ = LI.Query(Def); ValueIn = LRQ.valueIn(); } else { - // Query subranges. Pick the first matching one. + // Query subranges. Ensure that all matching ones take us to the same def + // (allowing some of them to be undef). ValueIn = nullptr; for (const LiveInterval::SubRange &S : LI.subranges()) { // Transform lanemask to a mask in the joined live interval. @@ -2288,8 +2289,12 @@ std::pair<const VNInfo*, unsigned> JoinVals::followCopyChain( if ((SMask & LaneMask).none()) continue; LiveQueryResult LRQ = S.Query(Def); - ValueIn = LRQ.valueIn(); - break; + if (!ValueIn) { + ValueIn = LRQ.valueIn(); + continue; + } + if (LRQ.valueIn() && ValueIn != LRQ.valueIn()) + return std::make_pair(VNI, TrackReg); } } if (ValueIn == nullptr) { |
