//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/LiveVariables.h"
+#include "llvm/ADT/DepthFirstIterator.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallSet.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/Support/Debug.h"
+#include "llvm/Support/ErrorHandling.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
-#include "llvm/Support/ErrorHandling.h"
-#include "llvm/ADT/DepthFirstIterator.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/SmallSet.h"
-#include "llvm/ADT/STLExtras.h"
#include <algorithm>
using namespace llvm;
for (unsigned i = 0, e = Kills.size(); i != e; ++i)
if (Kills[i]->getParent() == MBB)
return Kills[i];
- return NULL;
+ return nullptr;
}
void LiveVariables::VarInfo::dump() const {
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
dbgs() << " Alive in blocks: ";
for (SparseBitVector<>::iterator I = AliveBlocks.begin(),
E = AliveBlocks.end(); I != E; ++I)
dbgs() << "\n #" << i << ": " << *Kills[i];
dbgs() << "\n";
}
+#endif
}
/// getVarInfo - Get (possibly creating) a VarInfo object for the given vreg.
SmallSet<unsigned,4> &PartDefRegs) {
unsigned LastDefReg = 0;
unsigned LastDefDist = 0;
- MachineInstr *LastDef = NULL;
+ MachineInstr *LastDef = nullptr;
for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs) {
unsigned SubReg = *SubRegs;
MachineInstr *Def = PhysRegDef[SubReg];
}
if (!LastDef)
- return 0;
+ return nullptr;
PartDefRegs.insert(LastDefReg);
for (unsigned i = 0, e = LastDef->getNumOperands(); i != e; ++i) {
continue;
unsigned DefReg = MO.getReg();
if (TRI->isSubRegister(Reg, DefReg)) {
- PartDefRegs.insert(DefReg);
- for (MCSubRegIterator SubRegs(DefReg, TRI); SubRegs.isValid(); ++SubRegs)
+ for (MCSubRegIterator SubRegs(DefReg, TRI, /*IncludeSelf=*/true);
+ SubRegs.isValid(); ++SubRegs)
PartDefRegs.insert(*SubRegs);
}
}
true/*IsImp*/));
// Remember this use.
- PhysRegUse[Reg] = MI;
- for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs)
+ for (MCSubRegIterator SubRegs(Reg, TRI, /*IncludeSelf=*/true);
+ SubRegs.isValid(); ++SubRegs)
PhysRegUse[*SubRegs] = MI;
}
MachineInstr *LastDef = PhysRegDef[Reg];
MachineInstr *LastUse = PhysRegUse[Reg];
if (!LastDef && !LastUse)
- return 0;
+ return nullptr;
MachineInstr *LastRefOrPartRef = LastUse ? LastUse : LastDef;
unsigned LastRefOrPartRefDist = DistanceMap[LastRefOrPartRef];
// AX<dead> = AL<imp-def>
// = AL<kill>
// AX =
- MachineInstr *LastPartDef = 0;
+ MachineInstr *LastPartDef = nullptr;
unsigned LastPartDefDist = 0;
SmallSet<unsigned, 8> PartUses;
for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs) {
continue;
}
if (MachineInstr *Use = PhysRegUse[SubReg]) {
- PartUses.insert(SubReg);
- for (MCSubRegIterator SS(SubReg, TRI); SS.isValid(); ++SS)
+ for (MCSubRegIterator SS(SubReg, TRI, /*IncludeSelf=*/true); SS.isValid();
+ ++SS)
PartUses.insert(*SS);
unsigned Dist = DistanceMap[Use];
if (Dist > LastRefOrPartRefDist) {
LastSubRef->addRegisterKilled(SubReg, TRI, true);
else {
LastRefOrPartRef->addRegisterKilled(SubReg, TRI, true);
- PhysRegUse[SubReg] = LastRefOrPartRef;
- for (MCSubRegIterator SS(SubReg, TRI); SS.isValid(); ++SS)
+ for (MCSubRegIterator SS(SubReg, TRI, /*IncludeSelf=*/true);
+ SS.isValid(); ++SS)
PhysRegUse[*SS] = LastRefOrPartRef;
}
for (MCSubRegIterator SS(SubReg, TRI); SS.isValid(); ++SS)
for (MCSuperRegIterator SR(Reg, TRI); SR.isValid(); ++SR)
if ((PhysRegDef[*SR] || PhysRegUse[*SR]) && MO.clobbersPhysReg(*SR))
Super = *SR;
- HandlePhysRegKill(Super, 0);
+ HandlePhysRegKill(Super, nullptr);
}
}
void LiveVariables::HandlePhysRegDef(unsigned Reg, MachineInstr *MI,
- SmallVector<unsigned, 4> &Defs) {
+ SmallVectorImpl<unsigned> &Defs) {
// What parts of the register are previously defined?
SmallSet<unsigned, 32> Live;
if (PhysRegDef[Reg] || PhysRegUse[Reg]) {
- Live.insert(Reg);
- for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs)
+ for (MCSubRegIterator SubRegs(Reg, TRI, /*IncludeSelf=*/true);
+ SubRegs.isValid(); ++SubRegs)
Live.insert(*SubRegs);
} else {
for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs) {
if (Live.count(SubReg))
continue;
if (PhysRegDef[SubReg] || PhysRegUse[SubReg]) {
- Live.insert(SubReg);
- for (MCSubRegIterator SS(SubReg, TRI); SS.isValid(); ++SS)
+ for (MCSubRegIterator SS(SubReg, TRI, /*IncludeSelf=*/true);
+ SS.isValid(); ++SS)
Live.insert(*SS);
}
}
}
void LiveVariables::UpdatePhysRegDefs(MachineInstr *MI,
- SmallVector<unsigned, 4> &Defs) {
+ SmallVectorImpl<unsigned> &Defs) {
while (!Defs.empty()) {
unsigned Reg = Defs.back();
Defs.pop_back();
- PhysRegDef[Reg] = MI;
- PhysRegUse[Reg] = NULL;
- for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs) {
+ for (MCSubRegIterator SubRegs(Reg, TRI, /*IncludeSelf=*/true);
+ SubRegs.isValid(); ++SubRegs) {
unsigned SubReg = *SubRegs;
PhysRegDef[SubReg] = MI;
- PhysRegUse[SubReg] = NULL;
+ PhysRegUse[SubReg] = nullptr;
}
}
}
MRI = &mf.getRegInfo();
TRI = MF->getTarget().getRegisterInfo();
- ReservedRegisters = TRI->getReservedRegs(mf);
-
unsigned NumRegs = TRI->getNumRegs();
PhysRegDef = new MachineInstr*[NumRegs];
PhysRegUse = new MachineInstr*[NumRegs];
PHIVarInfo = new SmallVector<unsigned, 4>[MF->getNumBlockIDs()];
- std::fill(PhysRegDef, PhysRegDef + NumRegs, (MachineInstr*)0);
- std::fill(PhysRegUse, PhysRegUse + NumRegs, (MachineInstr*)0);
+ std::fill(PhysRegDef, PhysRegDef + NumRegs, nullptr);
+ std::fill(PhysRegUse, PhysRegUse + NumRegs, nullptr);
PHIJoins.clear();
// FIXME: LiveIntervals will be updated to remove its dependence on
EE = MBB->livein_end(); II != EE; ++II) {
assert(TargetRegisterInfo::isPhysicalRegister(*II) &&
"Cannot have a live-in virtual register!");
- HandlePhysRegDef(*II, 0, Defs);
+ HandlePhysRegDef(*II, nullptr, Defs);
}
// Loop over all of the instructions, processing them.
unsigned MOReg = UseRegs[i];
if (TargetRegisterInfo::isVirtualRegister(MOReg))
HandleVirtRegUse(MOReg, MBB, MI);
- else if (!ReservedRegisters[MOReg])
+ else if (!MRI->isReserved(MOReg))
HandlePhysRegUse(MOReg, MI);
}
unsigned MOReg = DefRegs[i];
if (TargetRegisterInfo::isVirtualRegister(MOReg))
HandleVirtRegDef(MOReg, MI);
- else if (!ReservedRegisters[MOReg])
+ else if (!MRI->isReserved(MOReg))
HandlePhysRegDef(MOReg, MI, Defs);
}
UpdatePhysRegDefs(MI, Defs);
// if they have PHI nodes, and if so, we simulate an assignment at the end
// of the current block.
if (!PHIVarInfo[MBB->getNumber()].empty()) {
- SmallVector<unsigned, 4>& VarInfoVec = PHIVarInfo[MBB->getNumber()];
+ SmallVectorImpl<unsigned> &VarInfoVec = PHIVarInfo[MBB->getNumber()];
- for (SmallVector<unsigned, 4>::iterator I = VarInfoVec.begin(),
+ for (SmallVectorImpl<unsigned>::iterator I = VarInfoVec.begin(),
E = VarInfoVec.end(); I != E; ++I)
// Mark it alive only in the block we are representing.
MarkVirtRegAliveInBlock(getVarInfo(*I),MRI->getVRegDef(*I)->getParent(),
MBB);
}
- // Finally, if the last instruction in the block is a return, make sure to
- // mark it as using all of the live-out values in the function.
- // Things marked both call and return are tail calls; do not do this for
- // them. The tail callee need not take the same registers as input
- // that it produces as output, and there are dependencies for its input
- // registers elsewhere.
- if (!MBB->empty() && MBB->back().isReturn()
- && !MBB->back().isCall()) {
- MachineInstr *Ret = &MBB->back();
-
- for (MachineRegisterInfo::liveout_iterator
- I = MF->getRegInfo().liveout_begin(),
- E = MF->getRegInfo().liveout_end(); I != E; ++I) {
- assert(TargetRegisterInfo::isPhysicalRegister(*I) &&
- "Cannot have a live-out virtual register!");
- HandlePhysRegUse(*I, Ret);
-
- // Add live-out registers as implicit uses.
- if (!Ret->readsRegister(*I))
- Ret->addOperand(MachineOperand::CreateReg(*I, false, true));
- }
- }
-
// MachineCSE may CSE instructions which write to non-allocatable physical
// registers across MBBs. Remember if any reserved register is liveout.
SmallSet<unsigned, 4> LiveOuts;
// available at the end of the basic block.
for (unsigned i = 0; i != NumRegs; ++i)
if ((PhysRegDef[i] || PhysRegUse[i]) && !LiveOuts.count(i))
- HandlePhysRegDef(i, 0, Defs);
+ HandlePhysRegDef(i, nullptr, Defs);
- std::fill(PhysRegDef, PhysRegDef + NumRegs, (MachineInstr*)0);
- std::fill(PhysRegUse, PhysRegUse + NumRegs, (MachineInstr*)0);
+ std::fill(PhysRegDef, PhysRegDef + NumRegs, nullptr);
+ std::fill(PhysRegUse, PhysRegUse + NumRegs, nullptr);
}
// Convert and transfer the dead / killed information we have gathered into
/// which is used in a PHI node. We map that to the BB the vreg is coming from.
///
void LiveVariables::analyzePHINodes(const MachineFunction& Fn) {
- for (MachineFunction::const_iterator I = Fn.begin(), E = Fn.end();
- I != E; ++I)
- for (MachineBasicBlock::const_iterator BBI = I->begin(), BBE = I->end();
- BBI != BBE && BBI->isPHI(); ++BBI)
- for (unsigned i = 1, e = BBI->getNumOperands(); i != e; i += 2)
- if (BBI->getOperand(i).readsReg())
- PHIVarInfo[BBI->getOperand(i + 1).getMBB()->getNumber()]
- .push_back(BBI->getOperand(i).getReg());
+ for (const auto &MBB : Fn)
+ for (const auto &BBI : MBB) {
+ if (!BBI.isPHI())
+ break;
+ for (unsigned i = 1, e = BBI.getNumOperands(); i != e; i += 2)
+ if (BBI.getOperand(i).readsReg())
+ PHIVarInfo[BBI.getOperand(i + 1).getMBB()->getNumber()]
+ .push_back(BBI.getOperand(i).getReg());
+ }
}
bool LiveVariables::VarInfo::isLiveIn(const MachineBasicBlock &MBB,
MachineBasicBlock *SuccBB) {
const unsigned NumNew = BB->getNumber();
- // All registers used by PHI nodes in SuccBB must be live through BB.
- for (MachineBasicBlock::iterator BBI = SuccBB->begin(),
- BBE = SuccBB->end(); BBI != BBE && BBI->isPHI(); ++BBI)
+ SmallSet<unsigned, 16> Defs, Kills;
+
+ MachineBasicBlock::iterator BBI = SuccBB->begin(), BBE = SuccBB->end();
+ for (; BBI != BBE && BBI->isPHI(); ++BBI) {
+ // Record the def of the PHI node.
+ Defs.insert(BBI->getOperand(0).getReg());
+
+ // All registers used by PHI nodes in SuccBB must be live through BB.
for (unsigned i = 1, e = BBI->getNumOperands(); i != e; i += 2)
if (BBI->getOperand(i+1).getMBB() == BB)
getVarInfo(BBI->getOperand(i).getReg()).AliveBlocks.set(NumNew);
+ }
+
+ // Record all vreg defs and kills of all instructions in SuccBB.
+ for (; BBI != BBE; ++BBI) {
+ for (MachineInstr::mop_iterator I = BBI->operands_begin(),
+ E = BBI->operands_end(); I != E; ++I) {
+ if (I->isReg() && TargetRegisterInfo::isVirtualRegister(I->getReg())) {
+ if (I->isDef())
+ Defs.insert(I->getReg());
+ else if (I->isKill())
+ Kills.insert(I->getReg());
+ }
+ }
+ }
// Update info for all live variables
for (unsigned i = 0, e = MRI->getNumVirtRegs(); i != e; ++i) {
unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
+
+ // If the Defs is defined in the successor it can't be live in BB.
+ if (Defs.count(Reg))
+ continue;
+
+ // If the register is either killed in or live through SuccBB it's also live
+ // through BB.
VarInfo &VI = getVarInfo(Reg);
- if (!VI.AliveBlocks.test(NumNew) && VI.isLiveIn(*SuccBB, Reg, *MRI))
+ if (Kills.count(Reg) || VI.AliveBlocks.test(SuccBB->getNumber()))
VI.AliveBlocks.set(NumNew);
}
}