diff options
Diffstat (limited to 'lib/CodeGen/LiveVariables.cpp')
-rw-r--r-- | lib/CodeGen/LiveVariables.cpp | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/lib/CodeGen/LiveVariables.cpp b/lib/CodeGen/LiveVariables.cpp index cba0371f25..16a79bb54e 100644 --- a/lib/CodeGen/LiveVariables.cpp +++ b/lib/CodeGen/LiveVariables.cpp @@ -230,8 +230,9 @@ MachineInstr *LiveVariables::FindLastPartialDef(unsigned Reg, /// implicit defs to a machine instruction if there was an earlier def of its /// super-register. void LiveVariables::HandlePhysRegUse(unsigned Reg, MachineInstr *MI) { + MachineInstr *LastDef = PhysRegDef[Reg]; // If there was a previous use or a "full" def all is well. - if (!PhysRegDef[Reg] && !PhysRegUse[Reg]) { + if (!LastDef && !PhysRegUse[Reg]) { // Otherwise, the last sub-register def implicitly defines this register. // e.g. // AH = @@ -265,6 +266,11 @@ void LiveVariables::HandlePhysRegUse(unsigned Reg, MachineInstr *MI) { } } } + else if (LastDef && !PhysRegUse[Reg] && + !LastDef->findRegisterDefOperand(Reg)) + // Last def defines the super register, add an implicit def of reg. + LastDef->addOperand(MachineOperand::CreateReg(Reg, + true/*IsDef*/, true/*IsImp*/)); // Remember this use. PhysRegUse[Reg] = MI; |