Extract method for detecting constant unallocatable physregs.
It is safe to move uses of such registers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148259 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/TargetInstrInfoImpl.cpp b/lib/CodeGen/TargetInstrInfoImpl.cpp
index 018b5e5..be25855 100644
--- a/lib/CodeGen/TargetInstrInfoImpl.cpp
+++ b/lib/CodeGen/TargetInstrInfoImpl.cpp
@@ -380,7 +380,6 @@
const MachineRegisterInfo &MRI = MF.getRegInfo();
const TargetMachine &TM = MF.getTarget();
const TargetInstrInfo &TII = *TM.getInstrInfo();
- const TargetRegisterInfo &TRI = *TM.getRegisterInfo();
// Remat clients assume operand 0 is the defined register.
if (!MI->getNumOperands() || !MI->getOperand(0).isReg())
@@ -432,19 +431,8 @@
// If the physreg has no defs anywhere, it's just an ambient register
// and we can freely move its uses. Alternatively, if it's allocatable,
// it could get allocated to something with a def during allocation.
- if (!MRI.def_empty(Reg))
+ if (!MRI.isConstantPhysReg(Reg, MF))
return false;
- BitVector AllocatableRegs = TRI.getAllocatableSet(MF, 0);
- if (AllocatableRegs.test(Reg))
- return false;
- // Check for a def among the register's aliases too.
- for (const unsigned *Alias = TRI.getAliasSet(Reg); *Alias; ++Alias) {
- unsigned AliasReg = *Alias;
- if (!MRI.def_empty(AliasReg))
- return false;
- if (AllocatableRegs.test(AliasReg))
- return false;
- }
} else {
// A physreg def. We can't remat it.
return false;