EAX = ..., AX<imp-def>
...
= AX
This creates a double-def. Apparently this used to be necessary but is no longer needed.
Thanks to Anton for pointing this out. Anton, I cannot create a test case without your uncommitted ARM patches. Please check in a test case for me.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72755
91177308-0d34-0410-b5e6-
96231b3b80d8
}
}
- // There was an earlier def of a super-register. Add implicit def to that MI.
- //
- // A: EAX = ...
- // B: ... = AX
- //
- // Add implicit def to A if there isn't a use of AX (or EAX) before B.
- if (!PhysRegUse[Reg]) {
- MachineInstr *Def = PhysRegDef[Reg];
- if (Def && !Def->modifiesRegister(Reg))
- Def->addOperand(MachineOperand::CreateReg(Reg,
- true /*IsDef*/,
- true /*IsImp*/));
- }
-
// Remember this use.
PhysRegUse[Reg] = MI;
for (const unsigned *SubRegs = TRI->getSubRegisters(Reg);