#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/Target/TargetInstrInfo.h"
-#include "llvm/Support/CommandLine.h"
+#include "llvm/Target/TargetMachine.h"
using namespace llvm;
-MachineRegisterInfo::MachineRegisterInfo(const TargetRegisterInfo &TRI) {
+MachineRegisterInfo::MachineRegisterInfo(const TargetRegisterInfo &TRI)
+ : TRI(&TRI), IsSSA(true), TracksLiveness(true) {
VRegInfo.reserve(256);
RegAllocHints.reserve(256);
- RegClass2VRegMap = new std::vector<unsigned>[TRI.getNumRegClasses()];
UsedPhysRegs.resize(TRI.getNumRegs());
-
+ UsedPhysRegMask.resize(TRI.getNumRegs());
+
// Create the physreg use/def lists.
PhysRegUseDefLists = new MachineOperand*[TRI.getNumRegs()];
memset(PhysRegUseDefLists, 0, sizeof(MachineOperand*)*TRI.getNumRegs());
MachineRegisterInfo::~MachineRegisterInfo() {
#ifndef NDEBUG
- for (unsigned i = 0, e = VRegInfo.size(); i != e; ++i)
- assert(VRegInfo[i].second == 0 && "Vreg use list non-empty still?");
+ clearVirtRegs();
for (unsigned i = 0, e = UsedPhysRegs.size(); i != e; ++i)
assert(!PhysRegUseDefLists[i] &&
"PhysRegUseDefLists has entries after all instructions are deleted");
#endif
delete [] PhysRegUseDefLists;
- delete [] RegClass2VRegMap;
}
/// setRegClass - Set the register class of the specified virtual register.
///
void
MachineRegisterInfo::setRegClass(unsigned Reg, const TargetRegisterClass *RC) {
- unsigned VR = Reg;
- Reg -= TargetRegisterInfo::FirstVirtualRegister;
- assert(Reg < VRegInfo.size() && "Invalid vreg!");
- const TargetRegisterClass *OldRC = VRegInfo[Reg].first;
VRegInfo[Reg].first = RC;
+}
- // Remove from old register class's vregs list. This may be slow but
- // fortunately this operation is rarely needed.
- std::vector<unsigned> &VRegs = RegClass2VRegMap[OldRC->getID()];
- std::vector<unsigned>::iterator I = std::find(VRegs.begin(), VRegs.end(), VR);
- VRegs.erase(I);
+const TargetRegisterClass *
+MachineRegisterInfo::constrainRegClass(unsigned Reg,
+ const TargetRegisterClass *RC,
+ unsigned MinNumRegs) {
+ const TargetRegisterClass *OldRC = getRegClass(Reg);
+ if (OldRC == RC)
+ return RC;
+ const TargetRegisterClass *NewRC = TRI->getCommonSubClass(OldRC, RC);
+ if (!NewRC || NewRC == OldRC)
+ return NewRC;
+ if (NewRC->getNumRegs() < MinNumRegs)
+ return 0;
+ setRegClass(Reg, NewRC);
+ return NewRC;
+}
- // Add to new register class's vregs list.
- RegClass2VRegMap[RC->getID()].push_back(VR);
+bool
+MachineRegisterInfo::recomputeRegClass(unsigned Reg, const TargetMachine &TM) {
+ const TargetInstrInfo *TII = TM.getInstrInfo();
+ const TargetRegisterClass *OldRC = getRegClass(Reg);
+ const TargetRegisterClass *NewRC = TRI->getLargestLegalSuperClass(OldRC);
+
+ // Stop early if there is no room to grow.
+ if (NewRC == OldRC)
+ return false;
+
+ // Accumulate constraints from all uses.
+ for (reg_nodbg_iterator I = reg_nodbg_begin(Reg), E = reg_nodbg_end(); I != E;
+ ++I) {
+ const TargetRegisterClass *OpRC =
+ I->getRegClassConstraint(I.getOperandNo(), TII, TRI);
+ if (unsigned SubIdx = I.getOperand().getSubReg()) {
+ if (OpRC)
+ NewRC = TRI->getMatchingSuperRegClass(NewRC, OpRC, SubIdx);
+ else
+ NewRC = TRI->getSubClassWithSubReg(NewRC, SubIdx);
+ } else if (OpRC)
+ NewRC = TRI->getCommonSubClass(NewRC, OpRC);
+ if (!NewRC || NewRC == OldRC)
+ return false;
+ }
+ setRegClass(Reg, NewRC);
+ return true;
}
/// createVirtualRegister - Create and return a new virtual register in the
unsigned
MachineRegisterInfo::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));
- RegAllocHints.push_back(std::make_pair(0, 0));
-
- if (!((&VRegInfo[0] == ArrayBase || VRegInfo.size() == 1)))
- // The vector reallocated, handle this now.
- HandleVRegListReallocation();
- unsigned VR = getLastVirtReg();
- RegClass2VRegMap[RegClass->getID()].push_back(VR);
- return VR;
-}
-
-/// HandleVRegListReallocation - We just added a virtual register to the
-/// VRegInfo info list and it reallocated. Update the use/def lists info
-/// pointers.
-void MachineRegisterInfo::HandleVRegListReallocation() {
- // The back pointers for the vreg lists point into the previous vector.
- // Update them to point to their correct slots.
- for (unsigned i = 0, e = VRegInfo.size(); i != e; ++i) {
- MachineOperand *List = VRegInfo[i].second;
- if (!List) continue;
- // Update the back-pointer to be accurate once more.
- List->Contents.Reg.Prev = &VRegInfo[i].second;
+ assert(RegClass->isAllocatable() &&
+ "Virtual register RegClass must be allocatable.");
+
+ // New virtual register number.
+ unsigned Reg = TargetRegisterInfo::index2VirtReg(getNumVirtRegs());
+ VRegInfo.grow(Reg);
+ VRegInfo[Reg].first = RegClass;
+ RegAllocHints.grow(Reg);
+ return Reg;
+}
+
+/// clearVirtRegs - Remove all virtual registers (after physreg assignment).
+void MachineRegisterInfo::clearVirtRegs() {
+#ifndef NDEBUG
+ for (unsigned i = 0, e = getNumVirtRegs(); i != e; ++i)
+ assert(VRegInfo[TargetRegisterInfo::index2VirtReg(i)].second == 0 &&
+ "Vreg use list non-empty still?");
+#endif
+ VRegInfo.clear();
+}
+
+/// Add MO to the linked list of operands for its register.
+void MachineRegisterInfo::addRegOperandToUseList(MachineOperand *MO) {
+ assert(!MO->isOnRegUseList() && "Already on list");
+ MachineOperand *&HeadRef = getRegUseDefListHead(MO->getReg());
+ MachineOperand *const Head = HeadRef;
+
+ // Head points to the first list element.
+ // Next is NULL on the last list element.
+ // Prev pointers are circular, so Head->Prev == Last.
+
+ // Head is NULL for an empty list.
+ if (!Head) {
+ MO->Contents.Reg.Prev = MO;
+ MO->Contents.Reg.Next = 0;
+ HeadRef = MO;
+ return;
+ }
+ assert(MO->getReg() == Head->getReg() && "Different regs on the same list!");
+
+ // Insert MO between Last and Head in the circular Prev chain.
+ MachineOperand *Last = Head->Contents.Reg.Prev;
+ assert(Last && "Inconsistent use list");
+ assert(MO->getReg() == Last->getReg() && "Different regs on the same list!");
+ Head->Contents.Reg.Prev = MO;
+ MO->Contents.Reg.Prev = Last;
+
+ // Def operands always precede uses. This allows def_iterator to stop early.
+ // Insert def operands at the front, and use operands at the back.
+ if (MO->isDef()) {
+ // Insert def at the front.
+ MO->Contents.Reg.Next = Head;
+ HeadRef = MO;
+ } else {
+ // Insert use at the end.
+ MO->Contents.Reg.Next = 0;
+ Last->Contents.Reg.Next = MO;
}
}
+/// Remove MO from its use-def list.
+void MachineRegisterInfo::removeRegOperandFromUseList(MachineOperand *MO) {
+ assert(MO->isOnRegUseList() && "Operand not on use list");
+ MachineOperand *&HeadRef = getRegUseDefListHead(MO->getReg());
+ MachineOperand *const Head = HeadRef;
+ assert(Head && "List already empty");
+
+ // Unlink this from the doubly linked list of operands.
+ MachineOperand *Next = MO->Contents.Reg.Next;
+ MachineOperand *Prev = MO->Contents.Reg.Prev;
+
+ // Prev links are circular, next link is NULL instead of looping back to Head.
+ if (MO == Head)
+ HeadRef = Next;
+ else
+ Prev->Contents.Reg.Next = Next;
+
+ (Next ? Next : Head)->Contents.Reg.Prev = Prev;
+
+ MO->Contents.Reg.Prev = 0;
+ MO->Contents.Reg.Next = 0;
+}
+
/// 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.
/// register or null if none is found. This assumes that the code is in SSA
/// form, so there should only be one definition.
MachineInstr *MachineRegisterInfo::getVRegDef(unsigned Reg) const {
- assert(Reg-TargetRegisterInfo::FirstVirtualRegister < VRegInfo.size() &&
- "Invalid vreg!");
// Since we are in SSA form, we can use the first definition.
- if (!def_empty(Reg))
- return &*def_begin(Reg);
- return 0;
+ def_iterator I = def_begin(Reg);
+ assert((I.atEnd() || llvm::next(I) == def_end()) &&
+ "getVRegDef assumes a single definition or no definition");
+ return !I.atEnd() ? &*I : 0;
}
-bool MachineRegisterInfo::hasOneUse(unsigned RegNo) const {
- use_iterator UI = use_begin(RegNo);
- if (UI == use_end())
- return false;
- return ++UI == use_end();
+/// getUniqueVRegDef - Return the unique machine instr that defines the
+/// specified virtual register or null if none is found. If there are
+/// multiple definitions or no definition, return null.
+MachineInstr *MachineRegisterInfo::getUniqueVRegDef(unsigned Reg) const {
+ if (def_empty(Reg)) return 0;
+ def_iterator I = def_begin(Reg);
+ if (llvm::next(I) != def_end())
+ return 0;
+ return &*I;
}
bool MachineRegisterInfo::hasOneNonDBGUse(unsigned RegNo) const {
}
}
-void MachineRegisterInfo::closePhysRegsUsed(const TargetRegisterInfo &TRI) {
- for (int i = UsedPhysRegs.find_first(); i >= 0;
- i = UsedPhysRegs.find_next(i))
- for (const unsigned *SS = TRI.getSubRegisters(i);
- unsigned SubReg = *SS; ++SS)
- if (SubReg > unsigned(i))
- UsedPhysRegs.set(SubReg);
-}
-
#ifndef NDEBUG
void MachineRegisterInfo::dumpUses(unsigned Reg) const {
for (use_iterator I = use_begin(Reg), E = use_end(); I != E; ++I)
I.getOperand().getParent()->dump();
}
#endif
+
+void MachineRegisterInfo::freezeReservedRegs(const MachineFunction &MF) {
+ ReservedRegs = TRI->getReservedRegs(MF);
+}
+
+bool MachineRegisterInfo::isConstantPhysReg(unsigned PhysReg,
+ const MachineFunction &MF) const {
+ assert(TargetRegisterInfo::isPhysicalRegister(PhysReg));
+
+ // Check if any overlapping register is modified.
+ for (MCRegAliasIterator AI(PhysReg, TRI, true); AI.isValid(); ++AI)
+ if (!def_empty(*AI))
+ return false;
+
+ // Check if any overlapping register is allocatable so it may be used later.
+ if (AllocatableRegs.empty())
+ AllocatableRegs = TRI->getAllocatableSet(MF);
+ for (MCRegAliasIterator AI(PhysReg, TRI, true); AI.isValid(); ++AI)
+ if (AllocatableRegs.test(*AI))
+ return false;
+ return true;
+}
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