diff options
| -rw-r--r-- | include/llvm/Target/TargetRegisterInfo.h | 6 | ||||
| -rw-r--r-- | lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp | 17 | ||||
| -rw-r--r-- | lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp | 16 | ||||
| -rw-r--r-- | lib/Target/X86/X86RegisterInfo.cpp | 2 |
4 files changed, 28 insertions, 13 deletions
diff --git a/include/llvm/Target/TargetRegisterInfo.h b/include/llvm/Target/TargetRegisterInfo.h index 1c5d7c7118..4c63568786 100644 --- a/include/llvm/Target/TargetRegisterInfo.h +++ b/include/llvm/Target/TargetRegisterInfo.h @@ -588,8 +588,10 @@ public: } /// getCrossCopyRegClass - Returns a legal register class to copy a register - /// in the specified class to or from. Returns NULL if it is possible to copy - /// between a two registers of the specified class. + /// in the specified class to or from. If it is possible to copy the register + /// directly without using a cross register class copy, return the specified + /// RC. Returns NULL if it is not possible to copy between a two registers of + /// the specified class. virtual const TargetRegisterClass * getCrossCopyRegClass(const TargetRegisterClass *RC) const { return NULL; 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; diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp index fe98cacb83..1f464f4be4 100644 --- a/lib/Target/X86/X86RegisterInfo.cpp +++ b/lib/Target/X86/X86RegisterInfo.cpp @@ -337,7 +337,7 @@ X86RegisterInfo::getCrossCopyRegClass(const TargetRegisterClass *RC) const { else return &X86::GR32RegClass; } - return NULL; + return RC; } unsigned |