Changes in directory llvm/lib/CodeGen/SelectionDAG:
ScheduleDAGRRList.cpp updated: 1.16 -> 1.17 --- Log message: Clean up. --- Diffs of the changes: (+11 -5) ScheduleDAGRRList.cpp | 16 +++++++++++----- 1 files changed, 11 insertions(+), 5 deletions(-) Index: llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp diff -u llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp:1.16 llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp:1.17 --- llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp:1.16 Wed Nov 1 16:17:06 2006 +++ llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp Wed Nov 1 16:39:30 2006 @@ -719,7 +719,14 @@ return SethiUllmanNumber; unsigned Opc = SU->Node->getOpcode(); - if (Opc == ISD::TokenFactor || Opc == ISD::CopyToReg) + if (Opc == ISD::CopyFromReg && !isCopyFromLiveIn(SU)) + // CopyFromReg should be close to its def because it restricts allocation + // choices. But if it is a livein then perhaps we want it closer to the + // uses so it can be coalesced. + SethiUllmanNumber = INT_MIN + 10; + else if (Opc == ISD::TokenFactor || Opc == ISD::CopyToReg) + // CopyToReg should be close to its uses to facilitate coalescing and avoid + // spilling. SethiUllmanNumber = INT_MAX - 10; else if (SU->NumSuccsLeft == 0) // If SU does not have a use, i.e. it doesn't produce a value that would @@ -727,10 +734,9 @@ // Give it a small SethiUllman number so it will be scheduled right before its // predecessors that it doesn't lengthen their live ranges. SethiUllmanNumber = INT_MIN + 10; - // FIXME: remove this else if? It seems to reduce register spills but often - // ends up increasing runtime. Need to investigate. - else if (SU->NumPredsLeft == 0 && - (Opc != ISD::CopyFromReg || isCopyFromLiveIn(SU))) + else if (SU->NumPredsLeft == 0) + // If SU does not have a def, schedule it close to its uses because it does + // not lengthen any live ranges. SethiUllmanNumber = INT_MAX - 10; else { int Extra = 0; _______________________________________________ llvm-commits mailing list llvm-commits@cs.uiuc.edu http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits