#ifndef LLVM_TARGET_TARGETREGISTERINFO_H
#define LLVM_TARGET_TARGETREGISTERINFO_H
+#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/ValueTypes.h"
-#include "llvm/ADT/DenseSet.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/CallingConv.h"
#include <cassert>
#include <functional>
class BitVector;
class MachineFunction;
-class MachineMove;
class RegScavenger;
template<class T> class SmallVectorImpl;
class raw_ostream;
-/// TargetRegisterDesc - This record contains all of the information known about
-/// a particular register. The Overlaps field contains a pointer to a zero
-/// terminated array of registers that this register aliases, starting with
-/// itself. This is needed for architectures like X86 which have AL alias AX
-/// alias EAX. The SubRegs field is a zero terminated array of registers that
-/// are sub-registers of the specific register, e.g. AL, AH are sub-registers of
-/// AX. The SuperRegs field is a zero terminated array of registers that are
-/// super-registers of the specific register, e.g. RAX, EAX, are super-registers
-/// of AX.
-///
-struct TargetRegisterDesc {
- const char *Name; // Printable name for the reg (for debugging)
- const unsigned *Overlaps; // Overlapping registers, described above
- const unsigned *SubRegs; // Sub-register set, described above
- const unsigned *SuperRegs; // Super-register set, described above
-};
-
class TargetRegisterClass {
public:
typedef const unsigned* iterator;
typedef const unsigned* const_iterator;
-
typedef const EVT* vt_iterator;
typedef const TargetRegisterClass* const * sc_iterator;
private:
- unsigned ID;
- const char *Name;
+ virtual void anchor();
+ const MCRegisterClass *MC;
const vt_iterator VTs;
- const sc_iterator SubClasses;
+ const unsigned *SubClassMask;
const sc_iterator SuperClasses;
- const sc_iterator SubRegClasses;
const sc_iterator SuperRegClasses;
- const unsigned RegSize, Alignment; // Size & Alignment of register in bytes
- const int CopyCost;
- const iterator RegsBegin, RegsEnd;
- DenseSet<unsigned> RegSet;
public:
- TargetRegisterClass(unsigned id,
- const char *name,
- const EVT *vts,
- const TargetRegisterClass * const *subcs,
+ TargetRegisterClass(const MCRegisterClass *MC, const EVT *vts,
+ const unsigned *subcm,
const TargetRegisterClass * const *supcs,
- const TargetRegisterClass * const *subregcs,
- const TargetRegisterClass * const *superregcs,
- unsigned RS, unsigned Al, int CC,
- iterator RB, iterator RE)
- : ID(id), Name(name), VTs(vts), SubClasses(subcs), SuperClasses(supcs),
- SubRegClasses(subregcs), SuperRegClasses(superregcs),
- RegSize(RS), Alignment(Al), CopyCost(CC), RegsBegin(RB), RegsEnd(RE) {
- for (iterator I = RegsBegin, E = RegsEnd; I != E; ++I)
- RegSet.insert(*I);
- }
+ const TargetRegisterClass * const *superregcs)
+ : MC(MC), VTs(vts), SubClassMask(subcm), SuperClasses(supcs),
+ SuperRegClasses(superregcs) {}
+
virtual ~TargetRegisterClass() {} // Allow subclasses
/// getID() - Return the register class ID number.
///
- unsigned getID() const { return ID; }
+ unsigned getID() const { return MC->getID(); }
/// getName() - Return the register class name for debugging.
///
- const char *getName() const { return Name; }
+ const char *getName() const { return MC->getName(); }
/// begin/end - Return all of the registers in this class.
///
- iterator begin() const { return RegsBegin; }
- iterator end() const { return RegsEnd; }
+ iterator begin() const { return MC->begin(); }
+ iterator end() const { return MC->end(); }
/// getNumRegs - Return the number of registers in this class.
///
- unsigned getNumRegs() const { return (unsigned)(RegsEnd-RegsBegin); }
+ unsigned getNumRegs() const { return MC->getNumRegs(); }
/// getRegister - Return the specified register in the class.
///
unsigned getRegister(unsigned i) const {
- assert(i < getNumRegs() && "Register number out of range!");
- return RegsBegin[i];
+ return MC->getRegister(i);
}
/// contains - Return true if the specified register is included in this
/// register class. This does not include virtual registers.
bool contains(unsigned Reg) const {
- return RegSet.count(Reg);
+ return MC->contains(Reg);
}
/// contains - Return true if both registers are in this class.
bool contains(unsigned Reg1, unsigned Reg2) const {
- return contains(Reg1) && contains(Reg2);
+ return MC->contains(Reg1, Reg2);
}
+ /// 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 MC->getSize(); }
+
+ /// getAlignment - Return the minimum required alignment for a register of
+ /// this class.
+ unsigned getAlignment() const { return MC->getAlignment(); }
+
+ /// getCopyCost - Return the cost of copying a value between two registers in
+ /// this class. A negative number means the register class is very expensive
+ /// to copy e.g. status flag register classes.
+ int getCopyCost() const { return MC->getCopyCost(); }
+
+ /// isAllocatable - Return true if this register class may be used to create
+ /// virtual registers.
+ bool isAllocatable() const { return MC->isAllocatable(); }
+
/// hasType - return true if this TargetRegisterClass has the ValueType vt.
///
bool hasType(EVT vt) const {
return I;
}
- /// subregclasses_begin / subregclasses_end - Loop over all of
- /// the subreg register classes of this register class.
- sc_iterator subregclasses_begin() const {
- return SubRegClasses;
- }
-
- sc_iterator subregclasses_end() const {
- sc_iterator I = SubRegClasses;
- while (*I != NULL) ++I;
- return I;
- }
-
- /// getSubRegisterRegClass - Return the register class of subregisters with
- /// index SubIdx, or NULL if no such class exists.
- const TargetRegisterClass* getSubRegisterRegClass(unsigned SubIdx) const {
- assert(SubIdx>0 && "Invalid subregister index");
- return SubRegClasses[SubIdx-1];
- }
-
/// superregclasses_begin / superregclasses_end - Loop over all of
/// the superreg register classes of this register class.
sc_iterator superregclasses_begin() const {
}
/// hasSubClass - return true if the specified TargetRegisterClass
- /// is a proper subset of this TargetRegisterClass.
- bool hasSubClass(const TargetRegisterClass *cs) const {
- for (int i = 0; SubClasses[i] != NULL; ++i)
- if (SubClasses[i] == cs)
- return true;
- return false;
+ /// is a proper sub-class of this TargetRegisterClass.
+ bool hasSubClass(const TargetRegisterClass *RC) const {
+ return RC != this && hasSubClassEq(RC);
}
- /// subclasses_begin / subclasses_end - Loop over all of the classes
- /// that are proper subsets of this register class.
- sc_iterator subclasses_begin() const {
- return SubClasses;
+ /// hasSubClassEq - Returns true if RC is a sub-class of or equal to this
+ /// class.
+ bool hasSubClassEq(const TargetRegisterClass *RC) const {
+ unsigned ID = RC->getID();
+ return (SubClassMask[ID / 32] >> (ID % 32)) & 1;
}
- sc_iterator subclasses_end() const {
- sc_iterator I = SubClasses;
- while (*I != NULL) ++I;
- return I;
+ /// hasSuperClass - return true if the specified TargetRegisterClass is a
+ /// proper super-class of this TargetRegisterClass.
+ bool hasSuperClass(const TargetRegisterClass *RC) const {
+ return RC->hasSubClass(this);
}
- /// hasSuperClass - return true if the specified TargetRegisterClass is a
- /// proper superset of this TargetRegisterClass.
- bool hasSuperClass(const TargetRegisterClass *cs) const {
- for (int i = 0; SuperClasses[i] != NULL; ++i)
- if (SuperClasses[i] == cs)
- return true;
- return false;
+ /// hasSuperClassEq - Returns true if RC is a super-class of or equal to this
+ /// class.
+ bool hasSuperClassEq(const TargetRegisterClass *RC) const {
+ return RC->hasSubClassEq(this);
}
- /// superclasses_begin / superclasses_end - Loop over all of the classes
- /// that are proper supersets of this register class.
- sc_iterator superclasses_begin() const {
- return SuperClasses;
+ /// getSubClassMask - Returns a bit vector of subclasses, including this one.
+ /// The vector is indexed by class IDs, see hasSubClassEq() above for how to
+ /// use it.
+ const unsigned *getSubClassMask() const {
+ return SubClassMask;
}
- sc_iterator superclasses_end() const {
- sc_iterator I = SuperClasses;
- while (*I != NULL) ++I;
- return I;
+ /// getSuperClasses - Returns a NULL terminated list of super-classes. The
+ /// classes are ordered by ID which is also a topological ordering from large
+ /// to small classes. The list does NOT include the current class.
+ sc_iterator getSuperClasses() const {
+ return SuperClasses;
}
/// isASubClass - return true if this TargetRegisterClass is a subset
return SuperClasses[0] != 0;
}
- /// 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.
+ /// getRawAllocationOrder - Returns the preferred order for allocating
+ /// registers from this register class in MF. The raw order comes directly
+ /// from the .td file and may include reserved registers that are not
+ /// allocatable. Register allocators should also make sure to allocate
+ /// callee-saved registers only after all the volatiles are used. The
+ /// RegisterClassInfo class provides filtered allocation orders with
+ /// callee-saved registers moved to the end.
///
- /// These methods take a MachineFunction argument, which can be used to tune
- /// the allocatable registers based on the characteristics of the function,
- /// subtarget, or other criteria.
+ /// The MachineFunction argument can be used to tune the allocatable
+ /// registers based on the characteristics of the function, subtarget, or
+ /// other criteria.
///
- /// Register allocators should account for the fact that an allocation
- /// order iterator may return a reserved register and always check
- /// if the register is allocatable (getAllocatableSet()) before using it.
+ /// By default, this method returns all registers in the class.
///
- /// By default, these methods return all registers in the class.
- ///
- virtual iterator allocation_order_begin(const MachineFunction &MF) const {
- return begin();
- }
- virtual iterator allocation_order_end(const MachineFunction &MF) const {
- return end();
+ virtual
+ ArrayRef<unsigned> getRawAllocationOrder(const MachineFunction &MF) const {
+ return makeArrayRef(begin(), getNumRegs());
}
-
- /// 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; }
-
- /// getAlignment - Return the minimum required alignment for a register of
- /// this class.
- unsigned getAlignment() const { return Alignment; }
-
- /// getCopyCost - Return the cost of copying a value between two registers in
- /// this class. A negative number means the register class is very expensive
- /// to copy e.g. status flag register classes.
- int getCopyCost() const { return CopyCost; }
};
+/// TargetRegisterInfoDesc - Extra information, not in MCRegisterDesc, about
+/// registers. These are used by codegen, not by MC.
+struct TargetRegisterInfoDesc {
+ unsigned CostPerUse; // Extra cost of instructions using register.
+ bool inAllocatableClass; // Register belongs to an allocatable regclass.
+};
/// TargetRegisterInfo base class - We assume that the target defines a static
/// array of TargetRegisterDesc objects that represent all of the machine
/// to this array so that we can turn register number into a register
/// descriptor.
///
-class TargetRegisterInfo {
-protected:
- const unsigned* SubregHash;
- const unsigned SubregHashSize;
- const unsigned* AliasesHash;
- const unsigned AliasesHashSize;
+class TargetRegisterInfo : public MCRegisterInfo {
public:
typedef const TargetRegisterClass * const * regclass_iterator;
private:
- const TargetRegisterDesc *Desc; // Pointer to the descriptor array
+ const TargetRegisterInfoDesc *InfoDesc; // Extra desc array for codegen
const char *const *SubRegIndexNames; // Names of subreg indexes.
- unsigned NumRegs; // Number of entries in the array
-
regclass_iterator RegClassBegin, RegClassEnd; // List of regclasses
- int CallFrameSetupOpcode, CallFrameDestroyOpcode;
-
protected:
- TargetRegisterInfo(const TargetRegisterDesc *D, unsigned NR,
+ TargetRegisterInfo(const TargetRegisterInfoDesc *ID,
regclass_iterator RegClassBegin,
regclass_iterator RegClassEnd,
- const char *const *subregindexnames,
- int CallFrameSetupOpcode = -1,
- int CallFrameDestroyOpcode = -1,
- const unsigned* subregs = 0,
- const unsigned subregsize = 0,
- const unsigned* aliases = 0,
- const unsigned aliasessize = 0);
+ const char *const *subregindexnames);
virtual ~TargetRegisterInfo();
public:
- enum { // Define some target independent constants
- /// NoRegister - This physical register is not a real target register. It
- /// is useful as a sentinal.
- NoRegister = 0,
+ // Register numbers can represent physical registers, virtual registers, and
+ // sometimes stack slots. The unsigned values are divided into these ranges:
+ //
+ // 0 Not a register, can be used as a sentinel.
+ // [1;2^30) Physical registers assigned by TableGen.
+ // [2^30;2^31) Stack slots. (Rarely used.)
+ // [2^31;2^32) Virtual registers assigned by MachineRegisterInfo.
+ //
+ // Further sentinels can be allocated from the small negative integers.
+ // DenseMapInfo<unsigned> uses -1u and -2u.
+
+ /// isStackSlot - Sometimes it is useful the be able to store a non-negative
+ /// frame index in a variable that normally holds a register. isStackSlot()
+ /// returns true if Reg is in the range used for stack slots.
+ ///
+ /// Note that isVirtualRegister() and isPhysicalRegister() cannot handle stack
+ /// slots, so if a variable may contains a stack slot, always check
+ /// isStackSlot() first.
+ ///
+ static bool isStackSlot(unsigned Reg) {
+ return int(Reg) >= (1 << 30);
+ }
+
+ /// stackSlot2Index - Compute the frame index from a register value
+ /// representing a stack slot.
+ static int stackSlot2Index(unsigned Reg) {
+ assert(isStackSlot(Reg) && "Not a stack slot");
+ return int(Reg - (1u << 30));
+ }
- /// FirstVirtualRegister - This is the first register number that is
- /// considered to be a 'virtual' register, which is part of the SSA
- /// namespace. This must be the same for all targets, which means that each
- /// target is limited to this fixed number of registers.
- FirstVirtualRegister = 16384
- };
+ /// index2StackSlot - Convert a non-negative frame index to a stack slot
+ /// register value.
+ static unsigned index2StackSlot(int FI) {
+ assert(FI >= 0 && "Cannot hold a negative frame index.");
+ return FI + (1u << 30);
+ }
/// 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;
+ assert(!isStackSlot(Reg) && "Not a register! Check isStackSlot() first.");
+ return int(Reg) > 0;
}
/// 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;
+ assert(!isStackSlot(Reg) && "Not a register! Check isStackSlot() first.");
+ return int(Reg) < 0;
}
/// virtReg2Index - Convert a virtual register number to a 0-based index.
/// The first virtual register in a function will get the index 0.
static unsigned virtReg2Index(unsigned Reg) {
- return Reg - FirstVirtualRegister;
+ assert(isVirtualRegister(Reg) && "Not a virtual register");
+ return Reg & ~(1u << 31);
}
/// index2VirtReg - Convert a 0-based index to a virtual register number.
/// This is the inverse operation of VirtReg2IndexFunctor below.
static unsigned index2VirtReg(unsigned Index) {
- return Index + FirstVirtualRegister;
+ return Index | (1u << 31);
}
/// getMinimalPhysRegClass - Returns the Register Class of a physical
BitVector getAllocatableSet(const MachineFunction &MF,
const TargetRegisterClass *RC = NULL) 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 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 {
- // The Overlaps set always begins with Reg itself.
- return get(RegNo).Overlaps + 1;
- }
-
- /// getOverlaps - Return a list of registers that overlap Reg, including
- /// itself. This is the same as the alias set except Reg is included in the
- /// list.
- /// These are exactly the registers in { x | regsOverlap(x, Reg) }.
- ///
- const unsigned *getOverlaps(unsigned RegNo) const {
- return get(RegNo).Overlaps;
- }
-
- /// getSubRegisters - Return the list of registers that are sub-registers of
- /// the specified register, or a null list of there are none. The list
- /// returned is zero terminated and sorted according to super-sub register
- /// relations. e.g. X86::RAX's sub-register list is EAX, AX, AL, AH.
- ///
- const unsigned *getSubRegisters(unsigned RegNo) const {
- return get(RegNo).SubRegs;
- }
-
- /// getSuperRegisters - Return the list of registers that are super-registers
- /// of the specified register, or a null list of there are none. The list
- /// returned is zero terminated and sorted according to super-sub register
- /// relations. e.g. X86::AL's super-register list is RAX, EAX, AX.
- ///
- const unsigned *getSuperRegisters(unsigned RegNo) const {
- return get(RegNo).SuperRegs;
+ /// getCostPerUse - Return the additional cost of using this register instead
+ /// of other registers in its class.
+ unsigned getCostPerUse(unsigned RegNo) const {
+ return InfoDesc[RegNo].CostPerUse;
}
- /// getName - Return the human-readable symbolic target-specific name for the
- /// specified physical register.
- const char *getName(unsigned RegNo) const {
- return get(RegNo).Name;
- }
-
- /// getNumRegs - Return the number of registers this target has (useful for
- /// sizing arrays holding per register information)
- unsigned getNumRegs() const {
- return NumRegs;
+ /// isInAllocatableClass - Return true if the register is in the allocation
+ /// of any register class.
+ bool isInAllocatableClass(unsigned RegNo) const {
+ return InfoDesc[RegNo].inAllocatableClass;
}
/// getSubRegIndexName - Return the human-readable symbolic target-specific
/// regsOverlap - Returns true if the two registers are equal or alias each
/// other. The registers may be virtual register.
bool regsOverlap(unsigned regA, unsigned regB) const {
- if (regA == regB)
- return true;
-
+ if (regA == regB) return true;
if (isVirtualRegister(regA) || isVirtualRegister(regB))
return false;
-
- // regA and regB are distinct physical registers. Do they alias?
- size_t index = (regA + regB * 37) & (AliasesHashSize-1);
- unsigned ProbeAmt = 0;
- while (AliasesHash[index*2] != 0 &&
- AliasesHash[index*2+1] != 0) {
- if (AliasesHash[index*2] == regA && AliasesHash[index*2+1] == regB)
- return true;
-
- index = (index + ProbeAmt) & (AliasesHashSize-1);
- ProbeAmt += 2;
+ for (const unsigned *regList = getOverlaps(regA)+1; *regList; ++regList) {
+ if (*regList == regB) return true;
}
-
return false;
}
/// isSubRegister - Returns true if regB is a sub-register of regA.
///
bool isSubRegister(unsigned regA, unsigned regB) const {
- // SubregHash is a simple quadratically probed hash table.
- size_t index = (regA + regB * 37) & (SubregHashSize-1);
- unsigned ProbeAmt = 2;
- while (SubregHash[index*2] != 0 &&
- SubregHash[index*2+1] != 0) {
- if (SubregHash[index*2] == regA && SubregHash[index*2+1] == regB)
- return true;
-
- index = (index + ProbeAmt) & (SubregHashSize-1);
- ProbeAmt += 2;
- }
-
- return false;
+ return isSuperRegister(regB, regA);
}
/// isSuperRegister - Returns true if regB is a super-register of regA.
///
bool isSuperRegister(unsigned regA, unsigned regB) const {
- return isSubRegister(regB, regA);
+ for (const unsigned *regList = getSuperRegisters(regA); *regList;++regList){
+ if (*regList == regB) return true;
+ }
+ return false;
}
/// getCalleeSavedRegs - Return a null-terminated list of all of the
/// callee saved registers on this target. The register should be in the
/// order of desired callee-save stack frame offset. The first register is
- /// closed to the incoming stack pointer if stack grows down, and vice versa.
+ /// closest to the incoming stack pointer if stack grows down, and vice versa.
+ ///
virtual const unsigned* getCalleeSavedRegs(const MachineFunction *MF = 0)
const = 0;
+ /// getCallPreservedMask - Return a mask of call-preserved registers for the
+ /// given calling convention on the current sub-target. The mask should
+ /// include all call-preserved aliases. This is used by the register
+ /// allocator to determine which registers can be live across a call.
+ ///
+ /// The mask is an array containing (TRI::getNumRegs()+31)/32 entries.
+ /// A set bit indicates that all bits of the corresponding register are
+ /// preserved across the function call. The bit mask is expected to be
+ /// sub-register complete, i.e. if A is preserved, so are all its
+ /// sub-registers.
+ ///
+ /// Bits are numbered from the LSB, so the bit for physical register Reg can
+ /// be found as (Mask[Reg / 32] >> Reg % 32) & 1.
+ /// NULL pointer is equivalent to an all-zero mask.
+ ///
+ virtual const uint32_t *getCallPreservedMask(CallingConv::ID) const {
+ // The default mask clobbers everything. All targets should override.
+ return 0;
+ }
/// getReservedRegs - Returns a bitset indexed by physical register number
/// indicating if a register is a special register that has particular uses
/// getMatchingSuperRegClass - Return a subclass of the specified register
/// class A so that each register in it has a sub-register of the
/// specified sub-register index which is in the specified register class B.
+ ///
+ /// TableGen will synthesize missing A sub-classes.
virtual const TargetRegisterClass *
getMatchingSuperRegClass(const TargetRegisterClass *A,
- const TargetRegisterClass *B, unsigned Idx) const {
- return 0;
- }
+ const TargetRegisterClass *B, unsigned Idx) const =0;
+
+ /// getSubClassWithSubReg - Returns the largest legal sub-class of RC that
+ /// supports the sub-register index Idx.
+ /// If no such sub-class exists, return NULL.
+ /// If all registers in RC already have an Idx sub-register, return RC.
+ ///
+ /// TableGen generates a version of this function that is good enough in most
+ /// cases. Targets can override if they have constraints that TableGen
+ /// doesn't understand. For example, the x86 sub_8bit sub-register index is
+ /// supported by the full GR32 register class in 64-bit mode, but only by the
+ /// GR32_ABCD regiister class in 32-bit mode.
+ ///
+ /// TableGen will synthesize missing RC sub-classes.
+ virtual const TargetRegisterClass *
+ getSubClassWithSubReg(const TargetRegisterClass *RC, unsigned Idx) const =0;
/// composeSubRegIndices - Return the subregister index you get from composing
/// two subregister indices.
}
/// getRegClass - Returns the register class associated with the enumeration
- /// value. See class TargetOperandInfo.
+ /// value. See class MCOperandInfo.
const TargetRegisterClass *getRegClass(unsigned i) const {
assert(i < getNumRegClasses() && "Register Class ID out of range");
return RegClassBegin[i];
}
+ /// getCommonSubClass - find the largest common subclass of A and B. Return
+ /// NULL if there is no common subclass.
+ const TargetRegisterClass *
+ getCommonSubClass(const TargetRegisterClass *A,
+ const TargetRegisterClass *B) const;
+
/// getPointerRegClass - Returns a TargetRegisterClass used for pointer
/// values. If a target supports multiple different pointer register classes,
/// kind specifies which one is indicated.
}
/// getCrossCopyRegClass - Returns a legal register class to copy a register
- /// in the specified class to or from. Returns NULL if it is possible to copy
- /// between a two registers of the specified class.
+ /// in the specified class to or from. If it is possible to copy the register
+ /// directly without using a cross register class copy, return the specified
+ /// RC. Returns NULL if it is not possible to copy between a two registers of
+ /// the specified class.
virtual const TargetRegisterClass *
getCrossCopyRegClass(const TargetRegisterClass *RC) const {
- return NULL;
+ return RC;
+ }
+
+ /// getLargestLegalSuperClass - Returns the largest super class of RC that is
+ /// legal to use in the current sub-target and has the same spill size.
+ /// The returned register class can be used to create virtual registers which
+ /// means that all its registers can be copied and spilled.
+ virtual const TargetRegisterClass*
+ getLargestLegalSuperClass(const TargetRegisterClass *RC) const {
+ /// The default implementation is very conservative and doesn't allow the
+ /// register allocator to inflate register classes.
+ return RC;
+ }
+
+ /// getRegPressureLimit - Return the register pressure "high water mark" for
+ /// the specific register class. The scheduler is in high register pressure
+ /// mode (for the specific register class) if it goes over the limit.
+ virtual unsigned getRegPressureLimit(const TargetRegisterClass *RC,
+ MachineFunction &MF) const {
+ return 0;
}
- /// getAllocationOrder - Returns the register allocation order for a specified
- /// register class in the form of a pair of TargetRegisterClass iterators.
- virtual std::pair<TargetRegisterClass::iterator,TargetRegisterClass::iterator>
- getAllocationOrder(const TargetRegisterClass *RC,
- unsigned HintType, unsigned HintReg,
- const MachineFunction &MF) const {
- return std::make_pair(RC->allocation_order_begin(MF),
- RC->allocation_order_end(MF));
+ /// getRawAllocationOrder - Returns the register allocation order for a
+ /// specified register class with a target-dependent hint. The returned list
+ /// may contain reserved registers that cannot be allocated.
+ ///
+ /// Register allocators need only call this function to resolve
+ /// target-dependent hints, but it should work without hinting as well.
+ virtual ArrayRef<unsigned>
+ getRawAllocationOrder(const TargetRegisterClass *RC,
+ unsigned HintType, unsigned HintReg,
+ const MachineFunction &MF) const {
+ return RC->getRawAllocationOrder(MF);
}
/// ResolveRegAllocHint - Resolves the specified register allocation hint
return 0;
}
+ /// avoidWriteAfterWrite - Return true if the register allocator should avoid
+ /// writing a register from RC in two consecutive instructions.
+ /// This can avoid pipeline stalls on certain architectures.
+ /// It does cause increased register pressure, though.
+ virtual bool avoidWriteAfterWrite(const TargetRegisterClass *RC) const {
+ return false;
+ }
+
/// UpdateRegAllocHint - A callback to allow target a chance to update
/// register allocation hints when a register is "changed" (e.g. coalesced)
/// to another register. e.g. On ARM, some virtual registers should target
return false;
}
+ /// useFPForScavengingIndex - returns true if the target wants to use
+ /// frame pointer based accesses to spill to the scavenger emergency spill
+ /// slot.
+ virtual bool useFPForScavengingIndex(const MachineFunction &MF) const {
+ return true;
+ }
+
/// requiresFrameIndexScavenging - returns true if the target requires post
/// PEI scavenging of registers for materializing frame index constants.
virtual bool requiresFrameIndexScavenging(const MachineFunction &MF) const {
}
/// getFrameIndexInstrOffset - Get the offset from the referenced frame
- /// index in the instruction, if the is one.
+ /// index in the instruction, if there is one.
virtual int64_t getFrameIndexInstrOffset(const MachineInstr *MI,
int Idx) const {
return 0;
return false; // Must return a value in order to compile with VS 2005
}
- /// 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
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!");
}
//===--------------------------------------------------------------------===//
/// Debug information queries.
- /// getDwarfRegNum - Map a target register to an equivalent dwarf register
- /// number. Returns -1 if there is no equivalent value. The second
- /// parameter allows targets to use different numberings for EH info and
- /// debugging info.
- virtual int getDwarfRegNum(unsigned RegNum, bool isEH) const = 0;
-
/// getFrameRegister - This method should return the register used as a base
/// for values allocated in the current stack frame.
virtual unsigned getFrameRegister(const MachineFunction &MF) const = 0;
- /// getRARegister - This method should return the register where the return
- /// address can be found.
- virtual unsigned getRARegister() const = 0;
+ /// getCompactUnwindRegNum - This function maps the register to the number for
+ /// compact unwind encoding. Return -1 if the register isn't valid.
+ virtual int getCompactUnwindRegNum(unsigned, bool) const {
+ return -1;
+ }
};
}
};
-/// getCommonSubClass - find the largest common subclass of A and B. Return NULL
-/// if there is no common subclass.
-const TargetRegisterClass *getCommonSubClass(const TargetRegisterClass *A,
- const TargetRegisterClass *B);
-
/// PrintReg - Helper class for printing registers on a raw_ostream.
/// Prints virtual and physical registers with or without a TRI instance.
///
/// The format is:
-/// %noreg - NoRegister
-/// %reg5 - a virtual register.
-/// %reg5:sub_8bit - a virtual register with sub-register index (with TRI).
-/// %EAX - a physical register
-/// %physreg17 - a physical register when no TRI instance given.
+/// %noreg - NoRegister
+/// %vreg5 - a virtual register.
+/// %vreg5:sub_8bit - a virtual register with sub-register index (with TRI).
+/// %EAX - a physical register
+/// %physreg17 - a physical register when no TRI instance given.
///
/// Usage: OS << PrintReg(Reg, TRI) << '\n';
///