diff options
Diffstat (limited to 'lib/CodeGen')
| -rw-r--r-- | lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp | 17 | ||||
| -rw-r--r-- | lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp | 16 |
2 files changed, 23 insertions, 10 deletions
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp index e3da208452..7b560d173e 100644 --- a/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp +++ b/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp @@ -570,13 +570,20 @@ void ScheduleDAGFast::ListScheduleBottomUp() { TRI->getMinimalPhysRegClass(Reg, VT); const TargetRegisterClass *DestRC = TRI->getCrossCopyRegClass(RC); - // If cross copy register class is null, then it must be possible copy - // the value directly. Do not try duplicate the def. + // If cross copy register class is the same as RC, then it must be + // possible copy the value directly. Do not try duplicate the def. + // If cross copy register class is not the same as RC, then it's + // possible to copy the value but it require cross register class copies + // and it is expensive. + // If cross copy register class is null, then it's not possible to copy + // the value at all. SUnit *NewDef = 0; - if (DestRC) + if (DestRC != RC) { NewDef = CopyAndMoveSuccessors(LRDef); - else - DestRC = RC; + if (!DestRC && !NewDef) + report_fatal_error("Can't handle live physical " + "register dependency!"); + } if (!NewDef) { // Issue copies, these can be expensive cross register class copies. SmallVector<SUnit*, 2> Copies; diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp index f1a5a6599b..5e60aa04ea 100644 --- a/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp +++ b/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp @@ -1140,13 +1140,19 @@ SUnit *ScheduleDAGRRList::PickNodeToScheduleBottomUp() { TRI->getMinimalPhysRegClass(Reg, VT); const TargetRegisterClass *DestRC = TRI->getCrossCopyRegClass(RC); - // If cross copy register class is null, then it must be possible copy - // the value directly. Do not try duplicate the def. + // If cross copy register class is the same as RC, then it must be possible + // copy the value directly. Do not try duplicate the def. + // If cross copy register class is not the same as RC, then it's possible to + // copy the value but it require cross register class copies and it is + // expensive. + // If cross copy register class is null, then it's not possible to copy + // the value at all. SUnit *NewDef = 0; - if (DestRC) + if (DestRC != RC) { NewDef = CopyAndMoveSuccessors(LRDef); - else - DestRC = RC; + if (!DestRC && !NewDef) + report_fatal_error("Can't handle live physical register dependency!"); + } if (!NewDef) { // Issue copies, these can be expensive cross register class copies. SmallVector<SUnit*, 2> Copies; |