#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/ADT/BitVector.h"
-#include "llvm/ADT/iterator.h"
+#include "llvm/ADT/IndexedMap.h"
#include <vector>
namespace llvm {
/// registers, including vreg register classes, use/def chains for registers,
/// etc.
class MachineRegisterInfo {
- /// VRegInfo - Information we keep for each virtual register. The entries in
- /// this vector are actually converted to vreg numbers by adding the
- /// TargetRegisterInfo::FirstVirtualRegister delta to their index.
+ const TargetRegisterInfo *const TRI;
+
+ /// IsSSA - True when the machine function is in SSA form and virtual
+ /// registers have a single def.
+ bool IsSSA;
+
+ /// VRegInfo - Information we keep for each virtual register.
///
/// Each element in this list contains the register class of the vreg and the
/// start of the use/def list for the register.
- std::vector<std::pair<const TargetRegisterClass*, MachineOperand*> > VRegInfo;
+ IndexedMap<std::pair<const TargetRegisterClass*, MachineOperand*>,
+ VirtReg2IndexFunctor> VRegInfo;
+
+ /// RegAllocHints - This vector records register allocation hints for virtual
+ /// registers. For each virtual register, it keeps a register and hint type
+ /// pair making up the allocation hint. Hint type is target specific except
+ /// for the value 0 which means the second value of the pair is the preferred
+ /// register for allocation. For example, if the hint is <0, 1024>, it means
+ /// the allocator should prefer the physical register allocated to the virtual
+ /// register of the hint.
+ IndexedMap<std::pair<unsigned, unsigned>, VirtReg2IndexFunctor> RegAllocHints;
/// PhysRegUseDefLists - This is an array of the head of the use/def list for
/// physical registers.
public:
explicit MachineRegisterInfo(const TargetRegisterInfo &TRI);
~MachineRegisterInfo();
-
+
+ //===--------------------------------------------------------------------===//
+ // Function State
+ //===--------------------------------------------------------------------===//
+
+ // isSSA - Returns true when the machine function is in SSA form. Early
+ // passes require the machine function to be in SSA form where every virtual
+ // register has a single defining instruction.
+ //
+ // The TwoAddressInstructionPass and PHIElimination passes take the machine
+ // function out of SSA form when they introduce multiple defs per virtual
+ // register.
+ bool isSSA() const { return IsSSA; }
+
+ // leaveSSA - Indicates that the machine function is no longer in SSA form.
+ void leaveSSA() { IsSSA = false; }
+
//===--------------------------------------------------------------------===//
// Register Info
//===--------------------------------------------------------------------===//
/// reg_begin/reg_end - Provide iteration support to walk over all definitions
/// and uses of a register within the MachineFunction that corresponds to this
/// MachineRegisterInfo object.
- template<bool Uses, bool Defs>
+ template<bool Uses, bool Defs, bool SkipDebug>
class defusechain_iterator;
/// reg_iterator/reg_begin/reg_end - Walk all defs and uses of the specified
/// register.
- typedef defusechain_iterator<true,true> reg_iterator;
+ typedef defusechain_iterator<true,true,false> reg_iterator;
reg_iterator reg_begin(unsigned RegNo) const {
return reg_iterator(getRegUseDefListHead(RegNo));
}
static reg_iterator reg_end() { return reg_iterator(0); }
+ /// reg_empty - Return true if there are no instructions using or defining the
+ /// specified register (it may be live-in).
+ bool reg_empty(unsigned RegNo) const { return reg_begin(RegNo) == reg_end(); }
+
+ /// reg_nodbg_iterator/reg_nodbg_begin/reg_nodbg_end - Walk all defs and uses
+ /// of the specified register, skipping those marked as Debug.
+ typedef defusechain_iterator<true,true,true> reg_nodbg_iterator;
+ reg_nodbg_iterator reg_nodbg_begin(unsigned RegNo) const {
+ return reg_nodbg_iterator(getRegUseDefListHead(RegNo));
+ }
+ static reg_nodbg_iterator reg_nodbg_end() { return reg_nodbg_iterator(0); }
+
+ /// reg_nodbg_empty - Return true if the only instructions using or defining
+ /// Reg are Debug instructions.
+ bool reg_nodbg_empty(unsigned RegNo) const {
+ return reg_nodbg_begin(RegNo) == reg_nodbg_end();
+ }
+
/// def_iterator/def_begin/def_end - Walk all defs of the specified register.
- typedef defusechain_iterator<false,true> def_iterator;
+ typedef defusechain_iterator<false,true,false> def_iterator;
def_iterator def_begin(unsigned RegNo) const {
return def_iterator(getRegUseDefListHead(RegNo));
}
static def_iterator def_end() { return def_iterator(0); }
+ /// def_empty - Return true if there are no instructions defining the
+ /// specified register (it may be live-in).
+ bool def_empty(unsigned RegNo) const { return def_begin(RegNo) == def_end(); }
+
/// use_iterator/use_begin/use_end - Walk all uses of the specified register.
- typedef defusechain_iterator<true,false> use_iterator;
+ typedef defusechain_iterator<true,false,false> use_iterator;
use_iterator use_begin(unsigned RegNo) const {
return use_iterator(getRegUseDefListHead(RegNo));
}
static use_iterator use_end() { return use_iterator(0); }
+ /// use_empty - Return true if there are no instructions using the specified
+ /// register.
+ bool use_empty(unsigned RegNo) const { return use_begin(RegNo) == use_end(); }
+
+ /// hasOneUse - Return true if there is exactly one instruction using the
+ /// specified register.
+ bool hasOneUse(unsigned RegNo) const;
+
+ /// use_nodbg_iterator/use_nodbg_begin/use_nodbg_end - Walk all uses of the
+ /// specified register, skipping those marked as Debug.
+ typedef defusechain_iterator<true,false,true> use_nodbg_iterator;
+ use_nodbg_iterator use_nodbg_begin(unsigned RegNo) const {
+ return use_nodbg_iterator(getRegUseDefListHead(RegNo));
+ }
+ static use_nodbg_iterator use_nodbg_end() { return use_nodbg_iterator(0); }
+ /// use_nodbg_empty - Return true if there are no non-Debug instructions
+ /// using the specified register.
+ bool use_nodbg_empty(unsigned RegNo) const {
+ return use_nodbg_begin(RegNo) == use_nodbg_end();
+ }
+
+ /// hasOneNonDBGUse - Return true if there is exactly one non-Debug
+ /// instruction using the specified register.
+ bool hasOneNonDBGUse(unsigned RegNo) const;
+
/// replaceRegWith - Replace all instances of FromReg with ToReg in the
/// machine function. This is like llvm-level X->replaceAllUsesWith(Y),
/// except that it also changes any definitions of the register as well.
/// getRegUseDefListHead - Return the head pointer for the register use/def
/// list for the specified virtual or physical register.
MachineOperand *&getRegUseDefListHead(unsigned RegNo) {
- if (RegNo < TargetRegisterInfo::FirstVirtualRegister)
- return PhysRegUseDefLists[RegNo];
- RegNo -= TargetRegisterInfo::FirstVirtualRegister;
- return VRegInfo[RegNo].second;
+ if (TargetRegisterInfo::isVirtualRegister(RegNo))
+ return VRegInfo[RegNo].second;
+ return PhysRegUseDefLists[RegNo];
}
MachineOperand *getRegUseDefListHead(unsigned RegNo) const {
- if (RegNo < TargetRegisterInfo::FirstVirtualRegister)
- return PhysRegUseDefLists[RegNo];
- RegNo -= TargetRegisterInfo::FirstVirtualRegister;
- return VRegInfo[RegNo].second;
+ if (TargetRegisterInfo::isVirtualRegister(RegNo))
+ return VRegInfo[RegNo].second;
+ return PhysRegUseDefLists[RegNo];
}
/// getVRegDef - Return the machine instr that defines the specified virtual
/// register or null if none is found. This assumes that the code is in SSA
/// form, so there should only be one definition.
MachineInstr *getVRegDef(unsigned Reg) const;
+
+ /// clearKillFlags - Iterate over all the uses of the given register and
+ /// clear the kill flag from the MachineOperand. This function is used by
+ /// optimization passes which extend register lifetimes and need only
+ /// preserve conservative kill flag information.
+ void clearKillFlags(unsigned Reg) const;
#ifndef NDEBUG
void dumpUses(unsigned RegNo) const;
//===--------------------------------------------------------------------===//
/// getRegClass - Return the register class of the specified virtual register.
+ ///
const TargetRegisterClass *getRegClass(unsigned Reg) const {
- Reg -= TargetRegisterInfo::FirstVirtualRegister;
- assert(Reg < VRegInfo.size() && "Invalid vreg!");
return VRegInfo[Reg].first;
}
-
+
+ /// setRegClass - Set the register class of the specified virtual register.
+ ///
+ void setRegClass(unsigned Reg, const TargetRegisterClass *RC);
+
+ /// constrainRegClass - Constrain the register class of the specified virtual
+ /// register to be a common subclass of RC and the current register class,
+ /// but only if the new class has at least MinNumRegs registers. Return the
+ /// new register class, or NULL if no such class exists.
+ /// This should only be used when the constraint is known to be trivial, like
+ /// GR32 -> GR32_NOSP. Beware of increasing register pressure.
+ ///
+ const TargetRegisterClass *constrainRegClass(unsigned Reg,
+ const TargetRegisterClass *RC,
+ unsigned MinNumRegs = 0);
+
+ /// recomputeRegClass - Try to find a legal super-class of Reg's register
+ /// class that still satisfies the constraints from the instructions using
+ /// Reg. Returns true if Reg was upgraded.
+ ///
+ /// This method can be used after constraints have been removed from a
+ /// virtual register, for example after removing instructions or splitting
+ /// the live range.
+ ///
+ bool recomputeRegClass(unsigned Reg, const TargetMachine&);
+
/// createVirtualRegister - Create and return a new virtual register in the
/// function with the specified register class.
///
- unsigned createVirtualRegister(const TargetRegisterClass *RegClass) {
- assert(RegClass && "Cannot create register without RegClass!");
- // Add a reg, but keep track of whether the vector reallocated or not.
- void *ArrayBase = VRegInfo.empty() ? 0 : &VRegInfo[0];
- VRegInfo.push_back(std::make_pair(RegClass, (MachineOperand*)0));
-
- if (&VRegInfo[0] == ArrayBase || VRegInfo.size() == 1)
- return getLastVirtReg();
+ unsigned createVirtualRegister(const TargetRegisterClass *RegClass);
+
+ /// getNumVirtRegs - Return the number of virtual registers created.
+ ///
+ unsigned getNumVirtRegs() const { return VRegInfo.size(); }
- // Otherwise, the vector reallocated, handle this now.
- HandleVRegListReallocation();
- return getLastVirtReg();
+ /// setRegAllocationHint - Specify a register allocation hint for the
+ /// specified virtual register.
+ void setRegAllocationHint(unsigned Reg, unsigned Type, unsigned PrefReg) {
+ RegAllocHints[Reg].first = Type;
+ RegAllocHints[Reg].second = PrefReg;
}
- /// getLastVirtReg - Return the highest currently assigned virtual register.
- ///
- unsigned getLastVirtReg() const {
- return (unsigned)VRegInfo.size()+TargetRegisterInfo::FirstVirtualRegister-1;
+ /// getRegAllocationHint - Return the register allocation hint for the
+ /// specified virtual register.
+ std::pair<unsigned, unsigned>
+ getRegAllocationHint(unsigned Reg) const {
+ return RegAllocHints[Reg];
}
-
-
+
+ /// getSimpleHint - Return the preferred register allocation hint, or 0 if a
+ /// standard simple hint (Type == 0) is not set.
+ unsigned getSimpleHint(unsigned Reg) const {
+ std::pair<unsigned, unsigned> Hint = getRegAllocationHint(Reg);
+ return Hint.first ? 0 : Hint.second;
+ }
+
+
//===--------------------------------------------------------------------===//
// Physical Register Use Info
//===--------------------------------------------------------------------===//
/// setPhysRegUsed - Mark the specified register used in this function.
/// This should only be called during and after register allocation.
void setPhysRegUsed(unsigned Reg) { UsedPhysRegs[Reg] = true; }
-
+
+ /// addPhysRegsUsed - Mark the specified registers used in this function.
+ /// This should only be called during and after register allocation.
+ void addPhysRegsUsed(const BitVector &Regs) { UsedPhysRegs |= Regs; }
+
/// setPhysRegUnused - Mark the specified register unused in this function.
/// This should only be called during and after register allocation.
void setPhysRegUnused(unsigned Reg) { UsedPhysRegs[Reg] = false; }
-
+
+ /// closePhysRegsUsed - Expand UsedPhysRegs to its transitive closure over
+ /// subregisters. That means that if R is used, so are all subregisters.
+ void closePhysRegsUsed(const TargetRegisterInfo&);
//===--------------------------------------------------------------------===//
// LiveIn/LiveOut Management
liveout_iterator liveout_begin() const { return LiveOuts.begin(); }
liveout_iterator liveout_end() const { return LiveOuts.end(); }
bool liveout_empty() const { return LiveOuts.empty(); }
+
+ bool isLiveIn(unsigned Reg) const;
+ bool isLiveOut(unsigned Reg) const;
+
+ /// getLiveInPhysReg - If VReg is a live-in virtual register, return the
+ /// corresponding live-in physical register.
+ unsigned getLiveInPhysReg(unsigned VReg) const;
+
+ /// getLiveInVirtReg - If PReg is a live-in physical register, return the
+ /// corresponding live-in physical register.
+ unsigned getLiveInVirtReg(unsigned PReg) const;
+
+ /// EmitLiveInCopies - Emit copies to initialize livein virtual registers
+ /// into the given entry block.
+ void EmitLiveInCopies(MachineBasicBlock *EntryMBB,
+ const TargetRegisterInfo &TRI,
+ const TargetInstrInfo &TII);
+
private:
void HandleVRegListReallocation();
/// operands in the function that use or define a specific register. If
/// ReturnUses is true it returns uses of registers, if ReturnDefs is true it
/// returns defs. If neither are true then you are silly and it always
- /// returns end().
- template<bool ReturnUses, bool ReturnDefs>
+ /// returns end(). If SkipDebug is true it skips uses marked Debug
+ /// when incrementing.
+ template<bool ReturnUses, bool ReturnDefs, bool SkipDebug>
class defusechain_iterator
- : public forward_iterator<MachineInstr, ptrdiff_t> {
+ : public std::iterator<std::forward_iterator_tag, MachineInstr, ptrdiff_t> {
MachineOperand *Op;
explicit defusechain_iterator(MachineOperand *op) : Op(op) {
// If the first node isn't one we're interested in, advance to one that
// we are interested in.
if (op) {
if ((!ReturnUses && op->isUse()) ||
- (!ReturnDefs && op->isDef()))
+ (!ReturnDefs && op->isDef()) ||
+ (SkipDebug && op->isDebug()))
++*this;
}
}
friend class MachineRegisterInfo;
public:
- typedef forward_iterator<MachineInstr, ptrdiff_t>::reference reference;
- typedef forward_iterator<MachineInstr, ptrdiff_t>::pointer pointer;
+ typedef std::iterator<std::forward_iterator_tag,
+ MachineInstr, ptrdiff_t>::reference reference;
+ typedef std::iterator<std::forward_iterator_tag,
+ MachineInstr, ptrdiff_t>::pointer pointer;
defusechain_iterator(const defusechain_iterator &I) : Op(I.Op) {}
defusechain_iterator() : Op(0) {}
// If this is an operand we don't care about, skip it.
while (Op && ((!ReturnUses && Op->isUse()) ||
- (!ReturnDefs && Op->isDef())))
+ (!ReturnDefs && Op->isDef()) ||
+ (SkipDebug && Op->isDebug())))
Op = Op->getNextOperandForReg();
return *this;
defusechain_iterator operator++(int) { // Postincrement
defusechain_iterator tmp = *this; ++*this; return tmp;
}
-
+
+ /// skipInstruction - move forward until reaching a different instruction.
+ /// Return the skipped instruction that is no longer pointed to, or NULL if
+ /// already pointing to end().
+ MachineInstr *skipInstruction() {
+ if (!Op) return 0;
+ MachineInstr *MI = Op->getParent();
+ do ++*this;
+ while (Op && Op->getParent() == MI);
+ return MI;
+ }
+
MachineOperand &getOperand() const {
assert(Op && "Cannot dereference end iterator!");
return *Op;
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