diff options
Diffstat (limited to 'lib/CodeGen/MachineRegisterInfo.cpp')
-rw-r--r-- | lib/CodeGen/MachineRegisterInfo.cpp | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/lib/CodeGen/MachineRegisterInfo.cpp b/lib/CodeGen/MachineRegisterInfo.cpp index 5d852f2..7b839f0 100644 --- a/lib/CodeGen/MachineRegisterInfo.cpp +++ b/lib/CodeGen/MachineRegisterInfo.cpp @@ -60,6 +60,20 @@ MachineRegisterInfo::setRegClass(unsigned Reg, const TargetRegisterClass *RC) { RegClass2VRegMap[RC->getID()].push_back(VR); } +const TargetRegisterClass * +MachineRegisterInfo::constrainRegClass(unsigned Reg, + const TargetRegisterClass *RC) { + const TargetRegisterClass *OldRC = getRegClass(Reg); + if (OldRC == RC) + return RC; + const TargetRegisterClass *NewRC = getCommonSubClass(OldRC, RC); + if (!NewRC) + return 0; + if (NewRC != OldRC) + setRegClass(Reg, NewRC); + return NewRC; +} + /// createVirtualRegister - Create and return a new virtual register in the /// function with the specified register class. /// |