Changes in directory llvm/lib/CodeGen:
LiveVariables.cpp updated: 1.62 -> 1.63
---
Log message:
Do away with kill / dead maps. Move kill / dead info onto MI's.
---
Diffs of the changes: (+107 -81)
LiveVariables.cpp | 188 ++++++++++++++++++++++++++++++------------------------
1 files changed, 107 insertions(+), 81 deletions(-)
Index: llvm/lib/CodeGen/LiveVariables.cpp
diff -u llvm/lib/CodeGen/LiveVariables.cpp:1.62
llvm/lib/CodeGen/LiveVariables.cpp:1.63
--- llvm/lib/CodeGen/LiveVariables.cpp:1.62 Fri Nov 10 02:38:19 2006
+++ llvm/lib/CodeGen/LiveVariables.cpp Wed Nov 15 14:51:59 2006
@@ -72,24 +72,56 @@
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 @@
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 @@
// 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 @@
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 @@
}
}
- // 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 @@
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 @@
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 @@
/// 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 @@
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
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