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-rw-r--r--include/llvm/CodeGen/LiveVariables.h131
-rw-r--r--lib/CodeGen/LiveVariables.cpp188
2 files changed, 143 insertions, 176 deletions
diff --git a/include/llvm/CodeGen/LiveVariables.h b/include/llvm/CodeGen/LiveVariables.h
index 95114c0b70..47801a9472 100644
--- a/include/llvm/CodeGen/LiveVariables.h
+++ b/include/llvm/CodeGen/LiveVariables.h
@@ -107,23 +107,6 @@ private:
///
std::vector<VarInfo> VirtRegInfo;
- /// RegistersKilled - This map keeps track of all of the registers that
- /// are dead immediately after an instruction reads its operands. If an
- /// instruction does not have an entry in this map, it kills no registers.
- ///
- std::map<MachineInstr*, std::vector<unsigned> > RegistersKilled;
-
- /// RegistersDead - This map keeps track of all of the registers that are
- /// dead immediately after an instruction executes, which are not dead after
- /// the operands are evaluated. In practice, this only contains registers
- /// which are defined by an instruction, but never used.
- ///
- std::map<MachineInstr*, std::vector<unsigned> > RegistersDead;
-
- /// Dummy - An always empty vector used for instructions without dead or
- /// killed operands.
- std::vector<unsigned> Dummy;
-
/// AllocatablePhysicalRegisters - This vector keeps track of which registers
/// are actually register allocatable by the target machine. We can not track
/// liveness for values that are not in this set.
@@ -141,6 +124,15 @@ private: // Intermediate data structures
PHIVarInfoMap PHIVarInfo;
+
+ /// addRegisterKilled - We have determined MI kills a register. Look for the
+ /// operand that uses it and mark it as IsKill.
+ void addRegisterKilled(unsigned IncomingReg, MachineInstr *MI);
+
+ /// addRegisterDead - We have determined MI defined a register without a use.
+ /// Look for the operand that defines it and mark it as IsDead.
+ void addRegisterDead(unsigned IncomingReg, MachineInstr *MI);
+
void HandlePhysRegUse(unsigned Reg, MachineInstr *MI);
void HandlePhysRegDef(unsigned Reg, MachineInstr *MI);
@@ -153,55 +145,17 @@ public:
virtual bool runOnMachineFunction(MachineFunction &MF);
- /// killed_iterator - Iterate over registers killed by a machine instruction
- ///
- typedef std::vector<unsigned>::iterator killed_iterator;
-
- std::vector<unsigned> &getKillsVector(MachineInstr *MI) {
- std::map<MachineInstr*, std::vector<unsigned> >::iterator I =
- RegistersKilled.find(MI);
- return I != RegistersKilled.end() ? I->second : Dummy;
- }
- std::vector<unsigned> &getDeadDefsVector(MachineInstr *MI) {
- std::map<MachineInstr*, std::vector<unsigned> >::iterator I =
- RegistersDead.find(MI);
- return I != RegistersDead.end() ? I->second : Dummy;
- }
-
-
- /// killed_begin/end - Get access to the range of registers killed by a
- /// machine instruction.
- killed_iterator killed_begin(MachineInstr *MI) {
- return getKillsVector(MI).begin();
- }
- killed_iterator killed_end(MachineInstr *MI) {
- return getKillsVector(MI).end();
- }
- std::pair<killed_iterator, killed_iterator>
- killed_range(MachineInstr *MI) {
- std::vector<unsigned> &V = getKillsVector(MI);
- return std::make_pair(V.begin(), V.end());
- }
-
/// KillsRegister - Return true if the specified instruction kills the
/// specified register.
bool KillsRegister(MachineInstr *MI, unsigned Reg) const;
- killed_iterator dead_begin(MachineInstr *MI) {
- return getDeadDefsVector(MI).begin();
- }
- killed_iterator dead_end(MachineInstr *MI) {
- return getDeadDefsVector(MI).end();
- }
- std::pair<killed_iterator, killed_iterator>
- dead_range(MachineInstr *MI) {
- std::vector<unsigned> &V = getDeadDefsVector(MI);
- return std::make_pair(V.begin(), V.end());
- }
-
/// RegisterDefIsDead - Return true if the specified instruction defines the
/// specified register, but that definition is dead.
bool RegisterDefIsDead(MachineInstr *MI, unsigned Reg) const;
+
+ /// ModifiesRegister - Return true if the specified instruction modifies the
+ /// specified register.
+ bool ModifiesRegister(MachineInstr *MI, unsigned Reg) const;
//===--------------------------------------------------------------------===//
// API to update live variable information
@@ -217,19 +171,9 @@ public:
/// instruction.
///
void addVirtualRegisterKilled(unsigned IncomingReg, MachineInstr *MI) {
- std::vector<unsigned> &V = RegistersKilled[MI];
- // Insert in a sorted order.
- if (V.empty() || IncomingReg > V.back()) {
- V.push_back(IncomingReg);
- } else {
- std::vector<unsigned>::iterator I = V.begin();
- for (; *I < IncomingReg; ++I)
- /*empty*/;
- if (*I != IncomingReg) // Don't insert duplicates.
- V.insert(I, IncomingReg);
- }
- getVarInfo(IncomingReg).Kills.push_back(MI);
- }
+ addRegisterKilled(IncomingReg, MI);
+ getVarInfo(IncomingReg).Kills.push_back(MI);
+ }
/// removeVirtualRegisterKilled - Remove the specified virtual
/// register from the live variable information. Returns true if the
@@ -241,12 +185,17 @@ public:
if (!getVarInfo(reg).removeKill(MI))
return false;
- std::vector<unsigned> &V = getKillsVector(MI);
- for (unsigned i = 0, e = V.size(); i != e; ++i)
- if (V[i] == reg) {
- V.erase(V.begin()+i);
- return true;
+ bool Removed = false;
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = MI->getOperand(i);
+ if (MO.isReg() && MO.isUse() && MO.getReg() == reg) {
+ MO.unsetIsKill();
+ Removed = true;
+ break;
}
+ }
+
+ assert(Removed && "Register is not used by this instruction!");
return true;
}
@@ -258,17 +207,7 @@ public:
/// register is dead after being used by the specified instruction.
///
void addVirtualRegisterDead(unsigned IncomingReg, MachineInstr *MI) {
- std::vector<unsigned> &V = RegistersDead[MI];
- // Insert in a sorted order.
- if (V.empty() || IncomingReg > V.back()) {
- V.push_back(IncomingReg);
- } else {
- std::vector<unsigned>::iterator I = V.begin();
- for (; *I < IncomingReg; ++I)
- /*empty*/;
- if (*I != IncomingReg) // Don't insert duplicates.
- V.insert(I, IncomingReg);
- }
+ addRegisterDead(IncomingReg, MI);
getVarInfo(IncomingReg).Kills.push_back(MI);
}
@@ -282,12 +221,16 @@ public:
if (!getVarInfo(reg).removeKill(MI))
return false;
- std::vector<unsigned> &V = getDeadDefsVector(MI);
- for (unsigned i = 0, e = V.size(); i != e; ++i)
- if (V[i] == reg) {
- V.erase(V.begin()+i);
- return true;
+ bool Removed = false;
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = MI->getOperand(i);
+ if (MO.isReg() && MO.isDef() && MO.getReg() == reg) {
+ MO.unsetIsDead();
+ Removed = true;
+ break;
}
+ }
+ assert(Removed && "Register is not defined by this instruction!");
return true;
}
@@ -301,8 +244,6 @@ public:
virtual void releaseMemory() {
VirtRegInfo.clear();
- RegistersKilled.clear();
- RegistersDead.clear();
}
/// getVarInfo - Return the VarInfo structure for the specified VIRTUAL
diff --git a/lib/CodeGen/LiveVariables.cpp b/lib/CodeGen/LiveVariables.cpp
index 3424f45bc1..f5c81da46f 100644
--- a/lib/CodeGen/LiveVariables.cpp
+++ b/lib/CodeGen/LiveVariables.cpp
@@ -72,24 +72,56 @@ LiveVariables::VarInfo &LiveVariables::getVarInfo(unsigned RegIdx) {
return VirtRegInfo[RegIdx];
}
+/// registerOverlap - Returns true if register 1 is equal to register 2
+/// or if register 1 is equal to any of alias of register 2.
+static bool registerOverlap(unsigned Reg1, unsigned Reg2,
+ const MRegisterInfo *RegInfo) {
+ bool isVirt1 = MRegisterInfo::isVirtualRegister(Reg1);
+ bool isVirt2 = MRegisterInfo::isVirtualRegister(Reg2);
+ if (isVirt1 != isVirt2)
+ return false;
+ if (Reg1 == Reg2)
+ return true;
+ else if (isVirt1)
+ return false;
+ for (const unsigned *AliasSet = RegInfo->getAliasSet(Reg2);
+ unsigned Alias = *AliasSet; ++AliasSet) {
+ if (Reg1 == Alias)
+ return true;
+ }
+ return false;
+}
+
bool LiveVariables::KillsRegister(MachineInstr *MI, unsigned Reg) const {
- std::map<MachineInstr*, std::vector<unsigned> >::const_iterator I =
- RegistersKilled.find(MI);
- if (I == RegistersKilled.end()) return false;
-
- // Do a binary search, as these lists can grow pretty big, particularly for
- // call instructions on targets with lots of call-clobbered registers.
- return std::binary_search(I->second.begin(), I->second.end(), Reg);
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = MI->getOperand(i);
+ if (MO.isReg() && MO.isKill()) {
+ if (registerOverlap(Reg, MO.getReg(), RegInfo))
+ return true;
+ }
+ }
+ return false;
}
bool LiveVariables::RegisterDefIsDead(MachineInstr *MI, unsigned Reg) const {
- std::map<MachineInstr*, std::vector<unsigned> >::const_iterator I =
- RegistersDead.find(MI);
- if (I == RegistersDead.end()) return false;
-
- // Do a binary search, as these lists can grow pretty big, particularly for
- // call instructions on targets with lots of call-clobbered registers.
- return std::binary_search(I->second.begin(), I->second.end(), Reg);
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = MI->getOperand(i);
+ if (MO.isReg() && MO.isDead())
+ if (registerOverlap(Reg, MO.getReg(), RegInfo))
+ return true;
+ }
+ return false;
+}
+
+bool LiveVariables::ModifiesRegister(MachineInstr *MI, unsigned Reg) const {
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = MI->getOperand(i);
+ if (MO.isReg() && MO.isDef()) {
+ if (registerOverlap(Reg, MO.getReg(), RegInfo))
+ return true;
+ }
+ }
+ return false;
}
void LiveVariables::MarkVirtRegAliveInBlock(VarInfo &VRInfo,
@@ -149,6 +181,26 @@ void LiveVariables::HandleVirtRegUse(VarInfo &VRInfo, MachineBasicBlock *MBB,
MarkVirtRegAliveInBlock(VRInfo, *PI);
}
+void LiveVariables::addRegisterKilled(unsigned IncomingReg, MachineInstr *MI) {
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = MI->getOperand(i);
+ if (MO.isReg() && MO.isUse() && MO.getReg() == IncomingReg) {
+ MO.setIsKill();
+ break;
+ }
+ }
+}
+
+void LiveVariables::addRegisterDead(unsigned IncomingReg, MachineInstr *MI) {
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = MI->getOperand(i);
+ if (MO.isReg() && MO.isDef() && MO.getReg() == IncomingReg) {
+ MO.setIsDead();
+ break;
+ }
+ }
+}
+
void LiveVariables::HandlePhysRegUse(unsigned Reg, MachineInstr *MI) {
PhysRegInfo[Reg] = MI;
PhysRegUsed[Reg] = true;
@@ -164,9 +216,9 @@ void LiveVariables::HandlePhysRegDef(unsigned Reg, MachineInstr *MI) {
// Does this kill a previous version of this register?
if (MachineInstr *LastUse = PhysRegInfo[Reg]) {
if (PhysRegUsed[Reg])
- RegistersKilled[LastUse].push_back(Reg);
+ addRegisterKilled(Reg, LastUse);
else
- RegistersDead[LastUse].push_back(Reg);
+ addRegisterDead(Reg, LastUse);
}
PhysRegInfo[Reg] = MI;
PhysRegUsed[Reg] = false;
@@ -175,9 +227,9 @@ void LiveVariables::HandlePhysRegDef(unsigned Reg, MachineInstr *MI) {
unsigned Alias = *AliasSet; ++AliasSet) {
if (MachineInstr *LastUse = PhysRegInfo[Alias]) {
if (PhysRegUsed[Alias])
- RegistersKilled[LastUse].push_back(Alias);
+ addRegisterKilled(Alias, LastUse);
else
- RegistersDead[LastUse].push_back(Alias);
+ addRegisterDead(Alias, LastUse);
}
PhysRegInfo[Alias] = MI;
PhysRegUsed[Alias] = false;
@@ -286,7 +338,7 @@ bool LiveVariables::runOnMachineFunction(MachineFunction &MF) {
}
}
- // Finally, if the last block in the function is a return, make sure to mark
+ // 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.
if (!MBB->empty() && TII.isReturn(MBB->back().getOpcode())) {
MachineInstr *Ret = &MBB->back();
@@ -295,6 +347,8 @@ bool LiveVariables::runOnMachineFunction(MachineFunction &MF) {
assert(MRegisterInfo::isPhysicalRegister(*I) &&
"Cannot have a live-in virtual register!");
HandlePhysRegUse(*I, Ret);
+ // Add live-out registers as implicit uses.
+ Ret->addRegOperand(*I, false, true);
}
}
@@ -305,30 +359,19 @@ bool LiveVariables::runOnMachineFunction(MachineFunction &MF) {
HandlePhysRegDef(i, 0);
}
- // Convert the information we have gathered into VirtRegInfo and transform it
- // into a form usable by RegistersKilled.
+ // Convert and transfer the dead / killed information we have gathered into
+ // VirtRegInfo onto MI's.
//
for (unsigned i = 0, e = VirtRegInfo.size(); i != e; ++i)
for (unsigned j = 0, e = VirtRegInfo[i].Kills.size(); j != e; ++j) {
if (VirtRegInfo[i].Kills[j] == VirtRegInfo[i].DefInst)
- RegistersDead[VirtRegInfo[i].Kills[j]].push_back(
- i + MRegisterInfo::FirstVirtualRegister);
-
+ addRegisterDead(i + MRegisterInfo::FirstVirtualRegister,
+ VirtRegInfo[i].Kills[j]);
else
- RegistersKilled[VirtRegInfo[i].Kills[j]].push_back(
- i + MRegisterInfo::FirstVirtualRegister);
+ addRegisterKilled(i + MRegisterInfo::FirstVirtualRegister,
+ VirtRegInfo[i].Kills[j]);
}
- // Walk through the RegistersKilled/Dead sets, and sort the registers killed
- // or dead. This allows us to use efficient binary search for membership
- // testing.
- for (std::map<MachineInstr*, std::vector<unsigned> >::iterator
- I = RegistersKilled.begin(), E = RegistersKilled.end(); I != E; ++I)
- std::sort(I->second.begin(), I->second.end());
- for (std::map<MachineInstr*, std::vector<unsigned> >::iterator
- I = RegistersDead.begin(), E = RegistersDead.end(); I != E; ++I)
- std::sort(I->second.begin(), I->second.end());
-
// Check to make sure there are no unreachable blocks in the MC CFG for the
// function. If so, it is due to a bug in the instruction selector or some
// other part of the code generator if this happens.
@@ -347,8 +390,8 @@ bool LiveVariables::runOnMachineFunction(MachineFunction &MF) {
/// the records for NewMI.
void LiveVariables::instructionChanged(MachineInstr *OldMI,
MachineInstr *NewMI) {
- // If the instruction defines any virtual registers, update the VarInfo for
- // the instruction.
+ // If the instruction defines any virtual registers, update the VarInfo,
+ // kill and dead information for the instruction.
for (unsigned i = 0, e = OldMI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = OldMI->getOperand(i);
if (MO.isRegister() && MO.getReg() &&
@@ -356,74 +399,57 @@ void LiveVariables::instructionChanged(MachineInstr *OldMI,
unsigned Reg = MO.getReg();
VarInfo &VI = getVarInfo(Reg);
if (MO.isDef()) {
+ if (MO.isDead()) {
+ MO.unsetIsDead();
+ addVirtualRegisterDead(Reg, NewMI);
+ }
// Update the defining instruction.
if (VI.DefInst == OldMI)
VI.DefInst = NewMI;
}
if (MO.isUse()) {
+ if (MO.isKill()) {
+ MO.unsetIsKill();
+ addVirtualRegisterKilled(Reg, NewMI);
+ }
// If this is a kill of the value, update the VI kills list.
if (VI.removeKill(OldMI))
VI.Kills.push_back(NewMI); // Yes, there was a kill of it
}
}
}
-
- // Move the killed information over...
- killed_iterator I, E;
- tie(I, E) = killed_range(OldMI);
- if (I != E) {
- std::vector<unsigned> &V = RegistersKilled[NewMI];
- bool WasEmpty = V.empty();
- V.insert(V.end(), I, E);
- if (!WasEmpty)
- std::sort(V.begin(), V.end()); // Keep the reg list sorted.
- RegistersKilled.erase(OldMI);
- }
-
- // Move the dead information over...
- tie(I, E) = dead_range(OldMI);
- if (I != E) {
- std::vector<unsigned> &V = RegistersDead[NewMI];
- bool WasEmpty = V.empty();
- V.insert(V.end(), I, E);
- if (!WasEmpty)
- std::sort(V.begin(), V.end()); // Keep the reg list sorted.
- RegistersDead.erase(OldMI);
- }
}
/// removeVirtualRegistersKilled - Remove all killed info for the specified
/// instruction.
void LiveVariables::removeVirtualRegistersKilled(MachineInstr *MI) {
- std::map<MachineInstr*, std::vector<unsigned> >::iterator I =
- RegistersKilled.find(MI);
- if (I == RegistersKilled.end()) return;
-
- std::vector<unsigned> &Regs = I->second;
- for (unsigned i = 0, e = Regs.size(); i != e; ++i) {
- if (MRegisterInfo::isVirtualRegister(Regs[i])) {
- bool removed = getVarInfo(Regs[i]).removeKill(MI);
- assert(removed && "kill not in register's VarInfo?");
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = MI->getOperand(i);
+ if (MO.isReg() && MO.isKill()) {
+ MO.unsetIsKill();
+ unsigned Reg = MO.getReg();
+ if (MRegisterInfo::isVirtualRegister(Reg)) {
+ bool removed = getVarInfo(Reg).removeKill(MI);
+ assert(removed && "kill not in register's VarInfo?");
+ }
}
}
- RegistersKilled.erase(I);
}
/// removeVirtualRegistersDead - Remove all of the dead registers for the
/// specified instruction from the live variable information.
void LiveVariables::removeVirtualRegistersDead(MachineInstr *MI) {
- std::map<MachineInstr*, std::vector<unsigned> >::iterator I =
- RegistersDead.find(MI);
- if (I == RegistersDead.end()) return;
-
- std::vector<unsigned> &Regs = I->second;
- for (unsigned i = 0, e = Regs.size(); i != e; ++i) {
- if (MRegisterInfo::isVirtualRegister(Regs[i])) {
- bool removed = getVarInfo(Regs[i]).removeKill(MI);
- assert(removed && "kill not in register's VarInfo?");
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = MI->getOperand(i);
+ if (MO.isReg() && MO.isDead()) {
+ MO.unsetIsDead();
+ unsigned Reg = MO.getReg();
+ if (MRegisterInfo::isVirtualRegister(Reg)) {
+ bool removed = getVarInfo(Reg).removeKill(MI);
+ assert(removed && "kill not in register's VarInfo?");
+ }
}
}
- RegistersDead.erase(I);
}
/// analyzePHINodes - Gather information about the PHI nodes in here. In
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-25 11:55:44 +0000