diff --git a/lib/CodeGen/RegAllocGreedy.cpp b/lib/CodeGen/RegAllocGreedy.cpp index 90d3810437e..ef083c1ccb8 100644 --- a/lib/CodeGen/RegAllocGreedy.cpp +++ b/lib/CodeGen/RegAllocGreedy.cpp @@ -1489,15 +1489,25 @@ unsigned RAGreedy::trySplit(LiveInterval &VirtReg, AllocationOrder &Order, } // Then isolate blocks with multiple uses. - SplitAnalysis::BlockPtrSet Blocks; - if (SA->getMultiUseBlocks(Blocks)) { - LiveRangeEdit LREdit(VirtReg, NewVRegs, this); - SE->reset(LREdit); - SE->splitSingleBlocks(Blocks); - setStage(NewVRegs.begin(), NewVRegs.end(), RS_Spill); - if (VerifyEnabled) - MF->verify(this, "After splitting live range around basic blocks"); + unsigned Reg = SA->getParent().reg; + bool SingleInstrs = RegClassInfo.isProperSubClass(MRI->getRegClass(Reg)); + LiveRangeEdit LREdit(VirtReg, NewVRegs, this); + SE->reset(LREdit); + ArrayRef UseBlocks = SA->getUseBlocks(); + for (unsigned i = 0; i != UseBlocks.size(); ++i) { + const SplitAnalysis::BlockInfo &BI = UseBlocks[i]; + if (SA->shouldSplitSingleBlock(BI, SingleInstrs)) + SE->splitSingleBlock(BI); } + // No blocks were split. + if (LREdit.empty()) + return 0; + + // We did split for some blocks. + SE->finish(); + setStage(NewVRegs.begin(), NewVRegs.end(), RS_Spill); + if (VerifyEnabled) + MF->verify(this, "After splitting live range around basic blocks"); // Don't assign any physregs. return 0;