//
//===----------------------------------------------------------------------===//
-#ifndef LLVM_CODEGEN_REGISTER_COALESCER_H
-#define LLVM_CODEGEN_REGISTER_COALESCER_H
+#ifndef LLVM_LIB_CODEGEN_REGISTERCOALESCER_H
+#define LLVM_LIB_CODEGEN_REGISTERCOALESCER_H
namespace llvm {
class TargetRegisterClass;
class TargetInstrInfo;
- /// CoalescerPair - A helper class for register coalescers. When deciding if
+ /// A helper class for register coalescers. When deciding if
/// two registers can be coalesced, CoalescerPair can determine if a copy
/// instruction would become an identity copy after coalescing.
class CoalescerPair {
- const TargetInstrInfo &TII;
const TargetRegisterInfo &TRI;
- /// DstReg - The register that will be left after coalescing. It can be a
+ /// The register that will be left after coalescing. It can be a
/// virtual or physical register.
unsigned DstReg;
- /// SrcReg - the virtual register that will be coalesced into dstReg.
+ /// The virtual register that will be coalesced into dstReg.
unsigned SrcReg;
- /// subReg_ - The subregister index of srcReg in DstReg. It is possible the
- /// coalesce SrcReg into a subreg of the larger DstReg when DstReg is a
- /// virtual register.
- unsigned SubIdx;
+ /// The sub-register index of the old DstReg in the new coalesced register.
+ unsigned DstIdx;
- /// Partial - True when the original copy was a partial subregister copy.
+ /// The sub-register index of the old SrcReg in the new coalesced register.
+ unsigned SrcIdx;
+
+ /// True when the original copy was a partial subregister copy.
bool Partial;
- /// CrossClass - True when both regs are virtual, and newRC is constrained.
+ /// True when both regs are virtual and newRC is constrained.
bool CrossClass;
- /// Flipped - True when DstReg and SrcReg are reversed from the oriignal
+ /// True when DstReg and SrcReg are reversed from the original
/// copy instruction.
bool Flipped;
- /// NewRC - The register class of the coalesced register, or NULL if DstReg
- /// is a physreg.
+ /// The register class of the coalesced register, or NULL if DstReg
+ /// is a physreg. This register class may be a super-register of both
+ /// SrcReg and DstReg.
const TargetRegisterClass *NewRC;
public:
- CoalescerPair(const TargetInstrInfo &tii, const TargetRegisterInfo &tri)
- : TII(tii), TRI(tri), DstReg(0), SrcReg(0), SubIdx(0),
- Partial(false), CrossClass(false), Flipped(false), NewRC(0) {}
-
- /// setRegisters - set registers to match the copy instruction MI. Return
+ CoalescerPair(const TargetRegisterInfo &tri)
+ : TRI(tri), DstReg(0), SrcReg(0), DstIdx(0), SrcIdx(0),
+ Partial(false), CrossClass(false), Flipped(false), NewRC(nullptr) {}
+
+ /// Create a CoalescerPair representing a virtreg-to-physreg copy.
+ /// No need to call setRegisters().
+ CoalescerPair(unsigned VirtReg, unsigned PhysReg,
+ const TargetRegisterInfo &tri)
+ : TRI(tri), DstReg(PhysReg), SrcReg(VirtReg), DstIdx(0), SrcIdx(0),
+ Partial(false), CrossClass(false), Flipped(false), NewRC(nullptr) {}
+
+ /// Set registers to match the copy instruction MI. Return
/// false if MI is not a coalescable copy instruction.
bool setRegisters(const MachineInstr*);
- /// flip - Swap SrcReg and DstReg. Return false if swapping is impossible
+ /// Swap SrcReg and DstReg. Return false if swapping is impossible
/// because DstReg is a physical register, or SubIdx is set.
bool flip();
- /// isCoalescable - Return true if MI is a copy instruction that will become
+ /// Return true if MI is a copy instruction that will become
/// an identity copy after coalescing.
bool isCoalescable(const MachineInstr*) const;
- /// isPhys - Return true if DstReg is a physical register.
+ /// Return true if DstReg is a physical register.
bool isPhys() const { return !NewRC; }
- /// isPartial - Return true if the original copy instruction did not copy
+ /// Return true if the original copy instruction did not copy
/// the full register, but was a subreg operation.
bool isPartial() const { return Partial; }
- /// isCrossClass - Return true if DstReg is virtual and NewRC is a smaller
+ /// Return true if DstReg is virtual and NewRC is a smaller
/// register class than DstReg's.
bool isCrossClass() const { return CrossClass; }
- /// isFlipped - Return true when getSrcReg is the register being defined by
+ /// Return true when getSrcReg is the register being defined by
/// the original copy instruction.
bool isFlipped() const { return Flipped; }
- /// getDstReg - Return the register (virtual or physical) that will remain
+ /// Return the register (virtual or physical) that will remain
/// after coalescing.
unsigned getDstReg() const { return DstReg; }
- /// getSrcReg - Return the virtual register that will be coalesced away.
+ /// Return the virtual register that will be coalesced away.
unsigned getSrcReg() const { return SrcReg; }
- /// getSubIdx - Return the subregister index in DstReg that SrcReg will be
- /// coalesced into, or 0.
- unsigned getSubIdx() const { return SubIdx; }
+ /// Return the subregister index that DstReg will be coalesced into, or 0.
+ unsigned getDstIdx() const { return DstIdx; }
+
+ /// Return the subregister index that SrcReg will be coalesced into, or 0.
+ unsigned getSrcIdx() const { return SrcIdx; }
- /// getNewRC - Return the register class of the coalesced register.
+ /// Return the register class of the coalesced register.
const TargetRegisterClass *getNewRC() const { return NewRC; }
};
} // End llvm namespace