-//===- Target/MRegisterInfo.h - Target Register Information -------*-C++-*-===//
+//===- Target/MRegisterInfo.h - Target Register Information -----*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
//
// This file describes an abstract interface used to get information about a
// target machines register file. This information is used for a variety of
#define LLVM_TARGET_MREGISTERINFO_H
#include "llvm/CodeGen/MachineBasicBlock.h"
-#include <assert.h>
+#include "llvm/CodeGen/ValueTypes.h"
+#include <cassert>
+#include <functional>
-class Type;
-
-/// MRegisterDesc - This record contains all of the information known about a
-/// particular register.
-///
-struct MRegisterDesc {
- const char *Name; // Assembly language name for the register
- unsigned Flags; // Flags identifying register properties (defined below)
- unsigned TSFlags; // Target Specific Flags
-};
+namespace llvm {
-/// MRF namespace - This namespace contains flags that pertain to machine
-/// registers
+class Type;
+class MachineFunction;
+class MachineInstr;
+class TargetRegisterClass;
+
+/// TargetRegisterDesc - This record contains all of the information known about
+/// a particular register. The AliasSet field (if not null) contains a pointer
+/// to a Zero terminated array of registers that this register aliases. This is
+/// needed for architectures like X86 which have AL alias AX alias EAX.
+/// Registers that this does not apply to simply should set this to null.
///
-namespace MRF { // MRF = Machine Register Flags
- enum {
- INT8 = 1 << 0, // This is an 8 bit integer register
- INT16 = 1 << 1, // This is a 16 bit integer register
- INT32 = 1 << 2, // This is a 32 bit integer register
- INT64 = 1 << 3, // This is a 64 bit integer register
- INT128 = 1 << 4, // This is a 128 bit integer register
-
- FP32 = 1 << 5, // This is a 32 bit floating point register
- FP64 = 1 << 6, // This is a 64 bit floating point register
- FP80 = 1 << 7, // This is a 80 bit floating point register
- FP128 = 1 << 8, // This is a 128 bit floating point register
- };
+struct TargetRegisterDesc {
+ const char *Name; // Assembly language name for the register
+ const unsigned *AliasSet; // Register Alias Set, described above
};
class TargetRegisterClass {
-protected:
- TargetRegisterClass() {}
+public:
+ typedef const unsigned* iterator;
+ typedef const unsigned* const_iterator;
+private:
+ const MVT::ValueType VT;
+ const unsigned RegSize, Alignment; // Size & Alignment of register in bytes
+ const iterator RegsBegin, RegsEnd;
public:
+ TargetRegisterClass(MVT::ValueType vt, unsigned RS, unsigned Al, iterator RB, iterator RE)
+ : VT(vt), RegSize(RS), Alignment(Al), RegsBegin(RB), RegsEnd(RE) {}
+ virtual ~TargetRegisterClass() {} // Allow subclasses
+
+ /// getType - Return the declared value type for this register class.
+ ///
+ MVT::ValueType getType() const { return VT; }
+
+ // begin/end - Return all of the registers in this class.
+ iterator begin() const { return RegsBegin; }
+ iterator end() const { return RegsEnd; }
+
+ // getNumRegs - Return the number of registers in this class
+ unsigned getNumRegs() const { return RegsEnd-RegsBegin; }
+
+ // getRegister - Return the specified register in the class
+ unsigned getRegister(unsigned i) const {
+ assert(i < getNumRegs() && "Register number out of range!");
+ return RegsBegin[i];
+ }
- typedef unsigned* iterator;
- typedef unsigned* const_iterator;
+ /// contains - Return true if the specified register is included in this
+ /// register class.
+ bool contains(unsigned Reg) const {
+ for (iterator I = begin(), E = end(); I != E; ++I)
+ if (*I == Reg) return true;
+ return false;
+ }
+
+ /// allocation_order_begin/end - These methods define a range of registers
+ /// which specify the registers in this class that are valid to register
+ /// allocate, and the preferred order to allocate them in. For example,
+ /// callee saved registers should be at the end of the list, because it is
+ /// cheaper to allocate caller saved registers.
+ ///
+ /// These methods take a MachineFunction argument, which can be used to tune
+ /// the allocatable registers based on the characteristics of the function.
+ /// One simple example is that the frame pointer register can be used if
+ /// frame-pointer-elimination is performed.
+ ///
+ /// By default, these methods return all registers in the class.
+ ///
+ virtual iterator allocation_order_begin(MachineFunction &MF) const {
+ return begin();
+ }
+ virtual iterator allocation_order_end(MachineFunction &MF) const {
+ return end();
+ }
- iterator begin();
- iterator end();
- const_iterator begin() const;
- const_iterator end() const;
- virtual unsigned getNumRegs() const { return 0; }
- virtual unsigned getRegister(unsigned idx) const { return 0; }
- virtual unsigned getDataSize() const { return 0; }
+ /// getSize - Return the size of the register in bytes, which is also the size
+ /// of a stack slot allocated to hold a spilled copy of this register.
+ unsigned getSize() const { return RegSize; }
- //const std::vector<unsigned> &getRegsInClass(void) { return Regs; }
- //void getAliases(void);
+ /// getAlignment - Return the minimum required alignment for a register of
+ /// this class.
+ unsigned getAlignment() const { return Alignment; }
};
/// MRegisterInfo base class - We assume that the target defines a static array
-/// of MRegisterDesc objects that represent all of the machine registers that
-/// the target has. As such, we simply have to track a pointer to this array so
-/// that we can turn register number into a register descriptor.
+/// of TargetRegisterDesc objects that represent all of the machine registers
+/// that the target has. As such, we simply have to track a pointer to this
+/// array so that we can turn register number into a register descriptor.
///
class MRegisterInfo {
- const MRegisterDesc *Desc; // Pointer to the descriptor array
- unsigned NumRegs; // Number of entries in the array
+public:
+ typedef const TargetRegisterClass * const * regclass_iterator;
+private:
+ const TargetRegisterDesc *Desc; // Pointer to the descriptor array
+ unsigned NumRegs; // Number of entries in the array
+
+ regclass_iterator RegClassBegin, RegClassEnd; // List of regclasses
+
+ int CallFrameSetupOpcode, CallFrameDestroyOpcode;
protected:
- MRegisterInfo(const MRegisterDesc *D, unsigned NR) : Desc(D), NumRegs(NR) {}
+ MRegisterInfo(const TargetRegisterDesc *D, unsigned NR,
+ regclass_iterator RegClassBegin, regclass_iterator RegClassEnd,
+ int CallFrameSetupOpcode = -1, int CallFrameDestroyOpcode = -1);
+ virtual ~MRegisterInfo();
public:
- enum { // Define some target independant constants
+ enum { // Define some target independent constants
/// NoRegister - This 'hard' register is a 'noop' register for all backends.
/// This is used as the destination register for instructions that do not
/// produce a value. Some frontends may use this as an operand register to
/// mean special things, for example, the Sparc backend uses R0 to mean %g0
/// which always PRODUCES the value 0. The X86 backend does not use this
- /// value as an operand register.
+ /// value as an operand register, except for memory references.
///
NoRegister = 0,
FirstVirtualRegister = 1024,
};
- const MRegisterDesc &operator[](unsigned RegNo) const {
+ /// isPhysicalRegister - Return true if the specified register number is in
+ /// the physical register namespace.
+ static bool isPhysicalRegister(unsigned Reg) {
+ assert(Reg && "this is not a register!");
+ return Reg < FirstVirtualRegister;
+ }
+
+ /// isVirtualRegister - Return true if the specified register number is in
+ /// the virtual register namespace.
+ static bool isVirtualRegister(unsigned Reg) {
+ assert(Reg && "this is not a register!");
+ return Reg >= FirstVirtualRegister;
+ }
+
+ /// getAllocatableSet - Returns a bitset indexed by register number
+ /// indicating if a register is allocatable or not.
+ std::vector<bool> getAllocatableSet(MachineFunction &MF) const;
+
+ const TargetRegisterDesc &operator[](unsigned RegNo) const {
assert(RegNo < NumRegs &&
"Attempting to access record for invalid register number!");
return Desc[RegNo];
/// Provide a get method, equivalent to [], but more useful if we have a
/// pointer to this object.
///
- const MRegisterDesc &get(unsigned RegNo) const { return operator[](RegNo); }
+ const TargetRegisterDesc &get(unsigned RegNo) const {
+ return operator[](RegNo);
+ }
+ /// getAliasSet - Return the set of registers aliased by the specified
+ /// register, or a null list of there are none. The list returned is zero
+ /// terminated.
+ ///
+ const unsigned *getAliasSet(unsigned RegNo) const {
+ return get(RegNo).AliasSet;
+ }
- virtual MachineBasicBlock::iterator
- storeReg2RegOffset(MachineBasicBlock *MBB,
- MachineBasicBlock::iterator MBBI,
- unsigned SrcReg, unsigned DestReg,
- unsigned ImmOffset, unsigned dataSize) const = 0;
+ /// getName - Return the symbolic target specific name for the specified
+ /// physical register.
+ const char *getName(unsigned RegNo) const {
+ return get(RegNo).Name;
+ }
- virtual MachineBasicBlock::iterator
- loadRegOffset2Reg(MachineBasicBlock *MBB,
- MachineBasicBlock::iterator MBBI,
- unsigned DestReg, unsigned SrcReg,
- unsigned ImmOffset, unsigned dataSize) const = 0;
+ /// getNumRegs - Return the number of registers this target has
+ /// (useful for sizing arrays holding per register information)
+ unsigned getNumRegs() const {
+ return NumRegs;
+ }
- virtual MachineBasicBlock::iterator
- moveReg2Reg(MachineBasicBlock *MBB,
- MachineBasicBlock::iterator MBBI,
- unsigned DestReg, unsigned SrcReg, unsigned dataSize) const = 0;
+ /// areAliases - Returns true if the two registers alias each other,
+ /// false otherwise
+ bool areAliases(unsigned regA, unsigned regB) const {
+ for (const unsigned *Alias = getAliasSet(regA); *Alias; ++Alias)
+ if (*Alias == regB) return true;
+ return false;
+ }
- virtual MachineBasicBlock::iterator
- moveImm2Reg(MachineBasicBlock *MBB,
- MachineBasicBlock::iterator MBBI,
- unsigned DestReg, unsigned Imm, unsigned dataSize) const = 0;
+ /// getCalleeSaveRegs - Return a null-terminated list of all of the
+ /// callee-save registers on this target.
+ virtual const unsigned* getCalleeSaveRegs() const = 0;
- virtual MachineBasicBlock::iterator
- emitPrologue(MachineBasicBlock *MBB,
- MachineBasicBlock::iterator MBBI,
- unsigned numBytes) const = 0;
+ /// getCalleeSaveRegClasses - Return a null-terminated list of the preferred
+ /// register classes to spill each callee-saved register with. The order and
+ /// length of this list match the getCalleeSaveRegs() list.
+ virtual const TargetRegisterClass* const *getCalleeSaveRegClasses() const = 0;
- virtual MachineBasicBlock::iterator
- emitEpilogue(MachineBasicBlock *MBB,
- MachineBasicBlock::iterator MBBI,
- unsigned numBytes) const = 0;
+ //===--------------------------------------------------------------------===//
+ // Register Class Information
+ //
- virtual const unsigned* getCalleeSaveRegs() const = 0;
- virtual const unsigned* getCallerSaveRegs() const = 0;
+ /// Register class iterators
+ ///
+ regclass_iterator regclass_begin() const { return RegClassBegin; }
+ regclass_iterator regclass_end() const { return RegClassEnd; }
- virtual unsigned getFramePointer() const = 0;
- virtual unsigned getStackPointer() const = 0;
+ unsigned getNumRegClasses() const {
+ return regclass_end()-regclass_begin();
+ }
- /// Register class iterators
- typedef const TargetRegisterClass** const_iterator;
+ //===--------------------------------------------------------------------===//
+ // Interfaces used by the register allocator and stack frame
+ // manipulation passes to move data around between registers,
+ // immediates and memory. The return value is the number of
+ // instructions added to (negative if removed from) the basic block.
+ //
+
+ virtual void storeRegToStackSlot(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MI,
+ unsigned SrcReg, int FrameIndex,
+ const TargetRegisterClass *RC) const = 0;
+
+ virtual void loadRegFromStackSlot(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MI,
+ unsigned DestReg, int FrameIndex,
+ const TargetRegisterClass *RC) const = 0;
+
+ virtual void copyRegToReg(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MI,
+ unsigned DestReg, unsigned SrcReg,
+ const TargetRegisterClass *RC) const = 0;
+
+ /// isLoadFromStackSlot - If the specified machine instruction is a direct
+ /// load from a stack slot, return the virtual or physical register number of
+ /// the destination along with the FrameIndex of the loaded stack slot. If
+ /// not, return 0. This predicate must return false if the instruction has
+ /// any side effects other than loading from the stack slot.
+ virtual unsigned isLoadFromStackSlot(MachineInstr *MI, int &FrameIndex) const{
+ return 0;
+ }
+
+ /// foldMemoryOperand - Attempt to fold a load or store of the
+ /// specified stack slot into the specified machine instruction for
+ /// the specified operand. If this is possible, a new instruction
+ /// is returned with the specified operand folded, otherwise NULL is
+ /// returned. The client is responsible for removing the old
+ /// instruction and adding the new one in the instruction stream
+ virtual MachineInstr* foldMemoryOperand(MachineInstr* MI,
+ unsigned OpNum,
+ int FrameIndex) const {
+ return 0;
+ }
- virtual const_iterator regclass_begin() const = 0;
- virtual const_iterator regclass_end() const = 0;
+ /// getCallFrameSetup/DestroyOpcode - These methods return the opcode of the
+ /// frame setup/destroy instructions if they exist (-1 otherwise). Some
+ /// targets use pseudo instructions in order to abstract away the difference
+ /// between operating with a frame pointer and operating without, through the
+ /// use of these two instructions.
+ ///
+ int getCallFrameSetupOpcode() const { return CallFrameSetupOpcode; }
+ int getCallFrameDestroyOpcode() const { return CallFrameDestroyOpcode; }
+
+
+ /// eliminateCallFramePseudoInstr - This method is called during prolog/epilog
+ /// code insertion to eliminate call frame setup and destroy pseudo
+ /// instructions (but only if the Target is using them). It is responsible
+ /// for eliminating these instructions, replacing them with concrete
+ /// instructions. This method need only be implemented if using call frame
+ /// setup/destroy pseudo instructions.
+ ///
+ virtual void
+ eliminateCallFramePseudoInstr(MachineFunction &MF,
+ MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MI) const {
+ assert(getCallFrameSetupOpcode()== -1 && getCallFrameDestroyOpcode()== -1 &&
+ "eliminateCallFramePseudoInstr must be implemented if using"
+ " call frame setup/destroy pseudo instructions!");
+ assert(0 && "Call Frame Pseudo Instructions do not exist on this target!");
+ }
+
+ /// processFunctionBeforeFrameFinalized - This method is called immediately
+ /// before the specified functions frame layout (MF.getFrameInfo()) is
+ /// finalized. Once the frame is finalized, MO_FrameIndex operands are
+ /// replaced with direct constants. This method is optional. The return value
+ /// is the number of instructions added to (negative if removed from) the
+ /// basic block
+ ///
+ virtual void processFunctionBeforeFrameFinalized(MachineFunction &MF) const {
+ }
- virtual unsigned getNumRegClasses() const = 0;
- virtual const TargetRegisterClass* getRegClassForType(const Type* Ty) const=0;
+ /// eliminateFrameIndex - This method must be overriden to eliminate abstract
+ /// frame indices from instructions which may use them. The instruction
+ /// referenced by the iterator contains an MO_FrameIndex operand which must be
+ /// eliminated by this method. This method may modify or replace the
+ /// specified instruction, as long as it keeps the iterator pointing the the
+ /// finished product. The return value is the number of instructions
+ /// added to (negative if removed from) the basic block.
+ ///
+ virtual void eliminateFrameIndex(MachineBasicBlock::iterator MI) const = 0;
+
+ /// emitProlog/emitEpilog - These methods insert prolog and epilog code into
+ /// the function. The return value is the number of instructions
+ /// added to (negative if removed from) the basic block (entry for prologue).
+ ///
+ virtual void emitPrologue(MachineFunction &MF) const = 0;
+ virtual void emitEpilogue(MachineFunction &MF,
+ MachineBasicBlock &MBB) const = 0;
};
+// This is useful when building DenseMaps keyed on virtual registers
+struct VirtReg2IndexFunctor : std::unary_function<unsigned, unsigned> {
+ unsigned operator()(unsigned Reg) const {
+ return Reg - MRegisterInfo::FirstVirtualRegister;
+ }
+};
+
+} // End llvm namespace
+
#endif