diff --git a/lib/Target/MSP430/MSP430ISelLowering.cpp b/lib/Target/MSP430/MSP430ISelLowering.cpp index aea8befde1e..b7949119b77 100644 --- a/lib/Target/MSP430/MSP430ISelLowering.cpp +++ b/lib/Target/MSP430/MSP430ISelLowering.cpp @@ -967,6 +967,31 @@ const char *MSP430TargetLowering::getTargetNodeName(unsigned Opcode) const { } } +bool MSP430TargetLowering::isTruncateFree(const Type *Ty1, + const Type *Ty2) const { + if (!Ty1->isInteger() || !Ty2->isInteger()) + return false; + + return (Ty1->getPrimitiveSizeInBits() > Ty2->getPrimitiveSizeInBits()); +} + +bool MSP430TargetLowering::isTruncateFree(EVT VT1, EVT VT2) const { + if (!VT1.isInteger() || !VT2.isInteger()) + return false; + + return (VT1.getSizeInBits() > VT2.getSizeInBits()); +} + +bool MSP430TargetLowering::isZExtFree(const Type *Ty1, const Type *Ty2) const { + // MSP430 implicitly zero-extends 8-bit results in 16-bit registers. + return 0 && Ty1->isInteger(8) && Ty2->isInteger(16); +} + +bool MSP430TargetLowering::isZExtFree(EVT VT1, EVT VT2) const { + // MSP430 implicitly zero-extends 8-bit results in 16-bit registers. + return 0 && VT1 == MVT::i8 && VT2 == MVT::i16; +} + //===----------------------------------------------------------------------===// // Other Lowering Code //===----------------------------------------------------------------------===// diff --git a/lib/Target/MSP430/MSP430ISelLowering.h b/lib/Target/MSP430/MSP430ISelLowering.h index 4921500d392..6152a055bed 100644 --- a/lib/Target/MSP430/MSP430ISelLowering.h +++ b/lib/Target/MSP430/MSP430ISelLowering.h @@ -99,6 +99,23 @@ namespace llvm { std::pair getRegForInlineAsmConstraint(const std::string &Constraint, EVT VT) const; + /// isTruncateFree - Return true if it's free to truncate a value of type + /// Ty1 to type Ty2. e.g. On msp430 it's free to truncate a i16 value in + /// register R15W to i8 by referencing its sub-register R15B. + virtual bool isTruncateFree(const Type *Ty1, const Type *Ty2) const; + virtual bool isTruncateFree(EVT VT1, EVT VT2) const; + + /// isZExtFree - Return true if any actual instruction that defines a value + /// of type Ty1 implicit zero-extends the value to Ty2 in the result + /// register. This does not necessarily include registers defined in unknown + /// ways, such as incoming arguments, or copies from unknown virtual + /// registers. Also, if isTruncateFree(Ty2, Ty1) is true, this does not + /// necessarily apply to truncate instructions. e.g. on msp430, all + /// instructions that define 8-bit values implicit zero-extend the result + /// out to 16 bits. + virtual bool isZExtFree(const Type *Ty1, const Type *Ty2) const; + virtual bool isZExtFree(EVT VT1, EVT VT2) const; + MachineBasicBlock* EmitInstrWithCustomInserter(MachineInstr *MI, MachineBasicBlock *BB, DenseMap *EM) const;