using namespace llvm;
MachineRegisterInfo::MachineRegisterInfo(const TargetRegisterInfo &TRI)
- : TRI(&TRI), IsSSA(true) {
+ : TRI(&TRI), IsSSA(true), TracksLiveness(true) {
VRegInfo.reserve(256);
RegAllocHints.reserve(256);
UsedPhysRegs.resize(TRI.getNumRegs());
MachineRegisterInfo::~MachineRegisterInfo() {
#ifndef NDEBUG
- for (unsigned i = 0, e = getNumVirtRegs(); i != e; ++i)
- assert(VRegInfo[TargetRegisterInfo::index2VirtReg(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");
// New virtual register number.
unsigned Reg = TargetRegisterInfo::index2VirtReg(getNumVirtRegs());
-
- // Add a reg, but keep track of whether the vector reallocated or not.
- const unsigned FirstVirtReg = TargetRegisterInfo::index2VirtReg(0);
- void *ArrayBase = getNumVirtRegs() == 0 ? 0 : &VRegInfo[FirstVirtReg];
VRegInfo.grow(Reg);
VRegInfo[Reg].first = RegClass;
RegAllocHints.grow(Reg);
-
- if (ArrayBase && &VRegInfo[FirstVirtReg] != ArrayBase)
- // The vector reallocated, handle this now.
- HandleVRegListReallocation();
return Reg;
}
-/// 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 = getNumVirtRegs(); i != e; ++i) {
- unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
- MachineOperand *List = VRegInfo[Reg].second;
- if (!List) continue;
- // Update the back-pointer to be accurate once more.
- List->Contents.Reg.Prev = &VRegInfo[Reg].second;
+/// 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.
/// form, so there should only be one definition.
MachineInstr *MachineRegisterInfo::getVRegDef(unsigned Reg) const {
// 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 {
assert(TargetRegisterInfo::isPhysicalRegister(PhysReg));
// Check if any overlapping register is modified.
- for (const unsigned *R = TRI->getOverlaps(PhysReg); *R; ++R)
- if (!def_empty(*R))
+ 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 (const unsigned *R = TRI->getOverlaps(PhysReg); *R; ++R)
- if (AllocatableRegs.test(*R))
+ for (MCRegAliasIterator AI(PhysReg, TRI, true); AI.isValid(); ++AI)
+ if (AllocatableRegs.test(*AI))
return false;
return true;
}
projects / oota-llvm.git / blobdiff