#ifndef LLVM_TARGET_TARGETREGISTERINFO_H
#define LLVM_TARGET_TARGETREGISTERINFO_H
-#include "llvm/MC/MCRegisterInfo.h"
+#include "llvm/ADT/ArrayRef.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/ValueTypes.h"
-#include "llvm/ADT/ArrayRef.h"
-#include "llvm/CallingConv.h"
+#include "llvm/IR/CallingConv.h"
+#include "llvm/MC/MCRegisterInfo.h"
#include <cassert>
#include <functional>
class MachineFunction;
class RegScavenger;
template<class T> class SmallVectorImpl;
+class VirtRegMap;
class raw_ostream;
class TargetRegisterClass {
public:
- typedef const uint16_t* iterator;
- typedef const uint16_t* const_iterator;
+ typedef const MCPhysReg* iterator;
+ typedef const MCPhysReg* const_iterator;
typedef const MVT::SimpleValueType* vt_iterator;
typedef const TargetRegisterClass* const * sc_iterator;
// Instance variables filled by tablegen, do not use!
const MCRegisterClass *MC;
const vt_iterator VTs;
- const unsigned *SubClassMask;
+ const uint32_t *SubClassMask;
+ const uint16_t *SuperRegIndices;
const sc_iterator SuperClasses;
- const sc_iterator SuperRegClasses;
- ArrayRef<uint16_t> (*OrderFunc)(const MachineFunction&);
+ ArrayRef<MCPhysReg> (*OrderFunc)(const MachineFunction&);
/// getID() - Return the register class ID number.
///
return I;
}
- /// superregclasses_begin / superregclasses_end - Loop over all of
- /// the superreg register classes of this register class.
- sc_iterator superregclasses_begin() const {
- return SuperRegClasses;
- }
-
- sc_iterator superregclasses_end() const {
- sc_iterator I = SuperRegClasses;
- while (*I != NULL) ++I;
- return I;
- }
-
/// hasSubClass - return true if the specified TargetRegisterClass
/// is a proper sub-class of this TargetRegisterClass.
bool hasSubClass(const TargetRegisterClass *RC) const {
return SubClassMask;
}
+ /// getSuperRegIndices - Returns a 0-terminated list of sub-register indices
+ /// that project some super-register class into this register class. The list
+ /// has an entry for each Idx such that:
+ ///
+ /// There exists SuperRC where:
+ /// For all Reg in SuperRC:
+ /// this->contains(Reg:Idx)
+ ///
+ const uint16_t *getSuperRegIndices() const {
+ return SuperRegIndices;
+ }
+
/// 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.
///
/// By default, this method returns all registers in the class.
///
- ArrayRef<uint16_t> getRawAllocationOrder(const MachineFunction &MF) const {
+ ArrayRef<MCPhysReg> getRawAllocationOrder(const MachineFunction &MF) const {
return OrderFunc ? OrderFunc(MF) : makeArrayRef(begin(), getNumRegs());
}
};
private:
const TargetRegisterInfoDesc *InfoDesc; // Extra desc array for codegen
const char *const *SubRegIndexNames; // Names of subreg indexes.
+ // Pointer to array of lane masks, one per sub-reg index.
+ const unsigned *SubRegIndexLaneMasks;
+
regclass_iterator RegClassBegin, RegClassEnd; // List of regclasses
+ unsigned CoveringLanes;
protected:
TargetRegisterInfo(const TargetRegisterInfoDesc *ID,
regclass_iterator RegClassBegin,
regclass_iterator RegClassEnd,
- const char *const *subregindexnames);
+ const char *const *SRINames,
+ const unsigned *SRILaneMasks,
+ unsigned CoveringLanes);
virtual ~TargetRegisterInfo();
public:
const TargetRegisterClass *
getMinimalPhysRegClass(unsigned Reg, EVT VT = MVT::Other) const;
+ /// getAllocatableClass - Return the maximal subclass of the given register
+ /// class that is alloctable, or NULL.
+ const TargetRegisterClass *
+ getAllocatableClass(const TargetRegisterClass *RC) const;
+
/// getAllocatableSet - Returns a bitset indexed by register number
/// indicating if a register is allocatable or not. If a register class is
/// specified, returns the subset for the class.
/// getSubRegIndexName - Return the human-readable symbolic target-specific
/// name for the specified SubRegIndex.
const char *getSubRegIndexName(unsigned SubIdx) const {
- assert(SubIdx && "This is not a subregister index");
+ assert(SubIdx && SubIdx < getNumSubRegIndices() &&
+ "This is not a subregister index");
return SubRegIndexNames[SubIdx-1];
}
+ /// getSubRegIndexLaneMask - Return a bitmask representing the parts of a
+ /// register that are covered by SubIdx.
+ ///
+ /// Lane masks for sub-register indices are similar to register units for
+ /// physical registers. The individual bits in a lane mask can't be assigned
+ /// any specific meaning. They can be used to check if two sub-register
+ /// indices overlap.
+ ///
+ /// If the target has a register such that:
+ ///
+ /// getSubReg(Reg, A) overlaps getSubReg(Reg, B)
+ ///
+ /// then:
+ ///
+ /// getSubRegIndexLaneMask(A) & getSubRegIndexLaneMask(B) != 0
+ ///
+ /// The converse is not necessarily true. If two lane masks have a common
+ /// bit, the corresponding sub-registers may not overlap, but it can be
+ /// assumed that they usually will.
+ unsigned getSubRegIndexLaneMask(unsigned SubIdx) const {
+ // SubIdx == 0 is allowed, it has the lane mask ~0u.
+ assert(SubIdx < getNumSubRegIndices() && "This is not a subregister index");
+ return SubRegIndexLaneMasks[SubIdx];
+ }
+
+ /// The lane masks returned by getSubRegIndexLaneMask() above can only be
+ /// used to determine if sub-registers overlap - they can't be used to
+ /// determine if a set of sub-registers completely cover another
+ /// sub-register.
+ ///
+ /// The X86 general purpose registers have two lanes corresponding to the
+ /// sub_8bit and sub_8bit_hi sub-registers. Both sub_32bit and sub_16bit have
+ /// lane masks '3', but the sub_16bit sub-register doesn't fully cover the
+ /// sub_32bit sub-register.
+ ///
+ /// On the other hand, the ARM NEON lanes fully cover their registers: The
+ /// dsub_0 sub-register is completely covered by the ssub_0 and ssub_1 lanes.
+ /// This is related to the CoveredBySubRegs property on register definitions.
+ ///
+ /// This function returns a bit mask of lanes that completely cover their
+ /// sub-registers. More precisely, given:
+ ///
+ /// Covering = getCoveringLanes();
+ /// MaskA = getSubRegIndexLaneMask(SubA);
+ /// MaskB = getSubRegIndexLaneMask(SubB);
+ ///
+ /// If (MaskA & ~(MaskB & Covering)) == 0, then SubA is completely covered by
+ /// SubB.
+ unsigned getCoveringLanes() const { return CoveringLanes; }
+
/// 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 (isVirtualRegister(regA) || isVirtualRegister(regB))
return false;
- for (const uint16_t *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 {
- return isSuperRegister(regB, regA);
+ // Regunits are numerically ordered. Find a common unit.
+ MCRegUnitIterator RUA(regA, this);
+ MCRegUnitIterator RUB(regB, this);
+ do {
+ if (*RUA == *RUB) return true;
+ if (*RUA < *RUB) ++RUA;
+ else ++RUB;
+ } while (RUA.isValid() && RUB.isValid());
+ return false;
}
- /// isSuperRegister - Returns true if regB is a super-register of regA.
- ///
- bool isSuperRegister(unsigned regA, unsigned regB) const {
- for (const uint16_t *regList = getSuperRegisters(regA); *regList;++regList){
- if (*regList == regB) return true;
- }
+ /// hasRegUnit - Returns true if Reg contains RegUnit.
+ bool hasRegUnit(unsigned Reg, unsigned RegUnit) const {
+ for (MCRegUnitIterator Units(Reg, this); Units.isValid(); ++Units)
+ if (*Units == RegUnit)
+ return true;
return false;
}
/// order of desired callee-save stack frame offset. The first register is
/// closest to the incoming stack pointer if stack grows down, and vice versa.
///
- virtual const uint16_t* getCalleeSavedRegs(const MachineFunction *MF = 0)
+ virtual const MCPhysReg* getCalleeSavedRegs(const MachineFunction *MF = 0)
const = 0;
/// getCallPreservedMask - Return a mask of call-preserved registers for the
return MCRegisterInfo::getMatchingSuperReg(Reg, SubIdx, RC->MC);
}
- /// canCombineSubRegIndices - Given a register class and a list of
- /// subregister indices, return true if it's possible to combine the
- /// subregister indices into one that corresponds to a larger
- /// subregister. Return the new subregister index by reference. Note the
- /// new index may be zero if the given subregisters can be combined to
- /// form the whole register.
- virtual bool canCombineSubRegIndices(const TargetRegisterClass *RC,
- SmallVectorImpl<unsigned> &SubIndices,
- unsigned &NewSubIdx) const {
- return 0;
- }
-
/// 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 =0;
+ const TargetRegisterClass *B, unsigned Idx) const;
/// getSubClassWithSubReg - Returns the largest legal sub-class of RC that
/// supports the sub-register index Idx.
///
/// TableGen will synthesize missing RC sub-classes.
virtual const TargetRegisterClass *
- getSubClassWithSubReg(const TargetRegisterClass *RC, unsigned Idx) const =0;
+ getSubClassWithSubReg(const TargetRegisterClass *RC, unsigned Idx) const {
+ assert(Idx == 0 && "Target has no sub-registers");
+ return RC;
+ }
/// composeSubRegIndices - Return the subregister index you get from composing
/// two subregister indices.
///
+ /// The special null sub-register index composes as the identity.
+ ///
/// If R:a:b is the same register as R:c, then composeSubRegIndices(a, b)
/// returns c. Note that composeSubRegIndices does not tell you about illegal
/// compositions. If R does not have a subreg a, or R:a does not have a subreg
/// ssub_0:S0 - ssub_3:S3 subregs.
/// If you compose subreg indices dsub_1, ssub_0 you get ssub_2.
///
- virtual unsigned composeSubRegIndices(unsigned a, unsigned b) const {
- // This default implementation is correct for most targets.
- return b;
+ unsigned composeSubRegIndices(unsigned a, unsigned b) const {
+ if (!a) return b;
+ if (!b) return a;
+ return composeSubRegIndicesImpl(a, b);
+ }
+
+protected:
+ /// Overridden by TableGen in targets that have sub-registers.
+ virtual unsigned composeSubRegIndicesImpl(unsigned, unsigned) const {
+ llvm_unreachable("Target has no sub-registers");
}
+public:
+ /// getCommonSuperRegClass - Find a common super-register class if it exists.
+ ///
+ /// Find a register class, SuperRC and two sub-register indices, PreA and
+ /// PreB, such that:
+ ///
+ /// 1. PreA + SubA == PreB + SubB (using composeSubRegIndices()), and
+ ///
+ /// 2. For all Reg in SuperRC: Reg:PreA in RCA and Reg:PreB in RCB, and
+ ///
+ /// 3. SuperRC->getSize() >= max(RCA->getSize(), RCB->getSize()).
+ ///
+ /// SuperRC will be chosen such that no super-class of SuperRC satisfies the
+ /// requirements, and there is no register class with a smaller spill size
+ /// that satisfies the requirements.
+ ///
+ /// SubA and SubB must not be 0. Use getMatchingSuperRegClass() instead.
+ ///
+ /// Either of the PreA and PreB sub-register indices may be returned as 0. In
+ /// that case, the returned register class will be a sub-class of the
+ /// corresponding argument register class.
+ ///
+ /// The function returns NULL if no register class can be found.
+ ///
+ const TargetRegisterClass*
+ getCommonSuperRegClass(const TargetRegisterClass *RCA, unsigned SubA,
+ const TargetRegisterClass *RCB, unsigned SubB,
+ unsigned &PreA, unsigned &PreB) const;
+
//===--------------------------------------------------------------------===//
// Register Class Information
//
/// getPointerRegClass - Returns a TargetRegisterClass used for pointer
/// values. If a target supports multiple different pointer register classes,
/// kind specifies which one is indicated.
- virtual const TargetRegisterClass *getPointerRegClass(unsigned Kind=0) const {
+ virtual const TargetRegisterClass *
+ getPointerRegClass(const MachineFunction &MF, unsigned Kind=0) const {
llvm_unreachable("Target didn't implement getPointerRegClass!");
}
virtual const RegClassWeight &getRegClassWeight(
const TargetRegisterClass *RC) const = 0;
+ /// Get the weight in units of pressure for this register unit.
+ virtual unsigned getRegUnitWeight(unsigned RegUnit) const = 0;
+
/// Get the number of dimensions of register pressure.
virtual unsigned getNumRegPressureSets() const = 0;
+ /// Get the name of this register unit pressure set.
+ virtual const char *getRegPressureSetName(unsigned Idx) const = 0;
+
/// Get the register unit pressure limit for this dimension.
/// This limit must be adjusted dynamically for reserved registers.
virtual unsigned getRegPressureSetLimit(unsigned Idx) const = 0;
virtual const int *getRegClassPressureSets(
const TargetRegisterClass *RC) const = 0;
- /// 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<uint16_t>
- getRawAllocationOrder(const TargetRegisterClass *RC,
- unsigned HintType, unsigned HintReg,
- const MachineFunction &MF) const {
- return RC->getRawAllocationOrder(MF);
- }
-
- /// ResolveRegAllocHint - Resolves the specified register allocation hint
- /// to a physical register. Returns the physical register if it is successful.
- virtual unsigned ResolveRegAllocHint(unsigned Type, unsigned Reg,
- const MachineFunction &MF) const {
- if (Type == 0 && Reg && isPhysicalRegister(Reg))
- return Reg;
- return 0;
- }
+ /// Get the dimensions of register pressure impacted by this register unit.
+ /// Returns a -1 terminated array of pressure set IDs.
+ virtual const int *getRegUnitPressureSets(unsigned RegUnit) const = 0;
+
+ /// Get a list of 'hint' registers that the register allocator should try
+ /// first when allocating a physical register for the virtual register
+ /// VirtReg. These registers are effectively moved to the front of the
+ /// allocation order.
+ ///
+ /// The Order argument is the allocation order for VirtReg's register class
+ /// as returned from RegisterClassInfo::getOrder(). The hint registers must
+ /// come from Order, and they must not be reserved.
+ ///
+ /// The default implementation of this function can resolve
+ /// target-independent hints provided to MRI::setRegAllocationHint with
+ /// HintType == 0. Targets that override this function should defer to the
+ /// default implementation if they have no reason to change the allocation
+ /// order for VirtReg. There may be target-independent hints.
+ virtual void getRegAllocationHints(unsigned VirtReg,
+ ArrayRef<MCPhysReg> Order,
+ SmallVectorImpl<MCPhysReg> &Hints,
+ const MachineFunction &MF,
+ const VirtRegMap *VRM = 0) const;
/// avoidWriteAfterWrite - Return true if the register allocator should avoid
/// writing a register from RC in two consecutive instructions.
// Do nothing.
}
+ /// Allow the target to reverse allocation order of local live ranges. This
+ /// will generally allocate shorter local live ranges first. For targets with
+ /// many registers, this could reduce regalloc compile time by a large
+ /// factor. It is disabled by default for three reasons:
+ /// (1) Top-down allocation is simpler and easier to debug for targets that
+ /// don't benefit from reversing the order.
+ /// (2) Bottom-up allocation could result in poor evicition decisions on some
+ /// targets affecting the performance of compiled code.
+ /// (3) Bottom-up allocation is no longer guaranteed to optimally color.
+ virtual bool reverseLocalAssignment() const { return false; }
+
+ /// Allow the target to override register assignment heuristics based on the
+ /// live range size. If this returns false, then local live ranges are always
+ /// assigned in order regardless of their size. This is a temporary hook for
+ /// debugging downstream codegen failures exposed by regalloc.
+ virtual bool mayOverrideLocalAssignment() const { return true; }
+
+ /// Allow the target to override the cost of using a callee-saved register for
+ /// the first time. Default value of 0 means we will use a callee-saved
+ /// register if it is available.
+ virtual unsigned getCSRFirstUseCost() const { return 0; }
+
/// requiresRegisterScavenging - returns true if the target requires (and can
/// make use of) the register scavenger.
virtual bool requiresRegisterScavenging(const MachineFunction &MF) const {
return false;
}
+ /// trackLivenessAfterRegAlloc - returns true if the live-ins should be tracked
+ /// after register allocation.
+ virtual bool trackLivenessAfterRegAlloc(const MachineFunction &MF) const {
+ return false;
+ }
+
/// needsStackRealignment - true if storage within the function requires the
/// stack pointer to be aligned more than the normal calling convention calls
/// for.
llvm_unreachable("isFrameOffsetLegal does not exist on this target");
}
- /// 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 {
- llvm_unreachable("Call Frame Pseudo Instructions do not exist on this "
- "target!");
- }
-
/// saveScavengerRegister - Spill the register so it can be used by the
/// register scavenger. Return true if the register was spilled, false
/// 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 at the
- /// finished product. SPAdj is the SP adjustment due to call frame setup
- /// instruction.
+ /// finished product. SPAdj is the SP adjustment due to call frame setup
+ /// instruction. FIOperandNum is the FI operand number.
virtual void eliminateFrameIndex(MachineBasicBlock::iterator MI,
- int SPAdj, RegScavenger *RS=NULL) const = 0;
+ int SPAdj, unsigned FIOperandNum,
+ RegScavenger *RS = NULL) const = 0;
//===--------------------------------------------------------------------===//
/// Debug information queries.
};
+//===----------------------------------------------------------------------===//
+// SuperRegClassIterator
+//===----------------------------------------------------------------------===//
+//
+// Iterate over the possible super-registers for a given register class. The
+// iterator will visit a list of pairs (Idx, Mask) corresponding to the
+// possible classes of super-registers.
+//
+// Each bit mask will have at least one set bit, and each set bit in Mask
+// corresponds to a SuperRC such that:
+//
+// For all Reg in SuperRC: Reg:Idx is in RC.
+//
+// The iterator can include (O, RC->getSubClassMask()) as the first entry which
+// also satisfies the above requirement, assuming Reg:0 == Reg.
+//
+class SuperRegClassIterator {
+ const unsigned RCMaskWords;
+ unsigned SubReg;
+ const uint16_t *Idx;
+ const uint32_t *Mask;
+
+public:
+ /// Create a SuperRegClassIterator that visits all the super-register classes
+ /// of RC. When IncludeSelf is set, also include the (0, sub-classes) entry.
+ SuperRegClassIterator(const TargetRegisterClass *RC,
+ const TargetRegisterInfo *TRI,
+ bool IncludeSelf = false)
+ : RCMaskWords((TRI->getNumRegClasses() + 31) / 32),
+ SubReg(0),
+ Idx(RC->getSuperRegIndices()),
+ Mask(RC->getSubClassMask()) {
+ if (!IncludeSelf)
+ ++*this;
+ }
+
+ /// Returns true if this iterator is still pointing at a valid entry.
+ bool isValid() const { return Idx; }
+
+ /// Returns the current sub-register index.
+ unsigned getSubReg() const { return SubReg; }
+
+ /// Returns the bit mask if register classes that getSubReg() projects into
+ /// RC.
+ const uint32_t *getMask() const { return Mask; }
+
+ /// Advance iterator to the next entry.
+ void operator++() {
+ assert(isValid() && "Cannot move iterator past end.");
+ Mask += RCMaskWords;
+ SubReg = *Idx++;
+ if (!SubReg)
+ Idx = 0;
+ }
+};
+
// This is useful when building IndexedMaps keyed on virtual registers
struct VirtReg2IndexFunctor : public std::unary_function<unsigned, unsigned> {
unsigned operator()(unsigned Reg) const {
unsigned Reg;
unsigned SubIdx;
public:
- PrintReg(unsigned reg, const TargetRegisterInfo *tri = 0, unsigned subidx = 0)
+ explicit PrintReg(unsigned reg, const TargetRegisterInfo *tri = 0,
+ unsigned subidx = 0)
: TRI(tri), Reg(reg), SubIdx(subidx) {}
void print(raw_ostream&) const;
};
return OS;
}
+/// PrintRegUnit - Helper class for printing register units on a raw_ostream.
+///
+/// Register units are named after their root registers:
+///
+/// AL - Single root.
+/// FP0~ST7 - Dual roots.
+///
+/// Usage: OS << PrintRegUnit(Unit, TRI) << '\n';
+///
+class PrintRegUnit {
+protected:
+ const TargetRegisterInfo *TRI;
+ unsigned Unit;
+public:
+ PrintRegUnit(unsigned unit, const TargetRegisterInfo *tri)
+ : TRI(tri), Unit(unit) {}
+ void print(raw_ostream&) const;
+};
+
+static inline raw_ostream &operator<<(raw_ostream &OS, const PrintRegUnit &PR) {
+ PR.print(OS);
+ return OS;
+}
+
+/// PrintVRegOrUnit - It is often convenient to track virtual registers and
+/// physical register units in the same list.
+class PrintVRegOrUnit : protected PrintRegUnit {
+public:
+ PrintVRegOrUnit(unsigned VRegOrUnit, const TargetRegisterInfo *tri)
+ : PrintRegUnit(VRegOrUnit, tri) {}
+ void print(raw_ostream&) const;
+};
+
+static inline raw_ostream &operator<<(raw_ostream &OS,
+ const PrintVRegOrUnit &PR) {
+ PR.print(OS);
+ return OS;
+}
+
} // End llvm namespace
#endif