[llvm-commits] [llvm] r47362 - in /llvm/trunk: include/llvm/CodeGen/LiveVariables.h lib/CodeGen/LiveVariables.cpp
Bill Wendling
isanbard at gmail.com
Tue Feb 19 23:36:31 PST 2008
Author: void
Date: Wed Feb 20 01:36:31 2008
New Revision: 47362
URL: http://llvm.org/viewvc/llvm-project?rev=47362&view=rev
Log:
More constification of things. More comments added. No functionality
changes. (Sorry for any formatting changes that creeped in.)
Modified:
llvm/trunk/include/llvm/CodeGen/LiveVariables.h
llvm/trunk/lib/CodeGen/LiveVariables.cpp
Modified: llvm/trunk/include/llvm/CodeGen/LiveVariables.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/LiveVariables.h?rev=47362&r1=47361&r2=47362&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/LiveVariables.h (original)
+++ llvm/trunk/include/llvm/CodeGen/LiveVariables.h Wed Feb 20 01:36:31 2008
@@ -137,8 +137,8 @@
// register references as presumed dead across basic blocks.
MachineInstr **PhysRegInfo;
- // PhysRegUsed - Keep track whether the physical register has been used after
- // its last definition. This is local property.
+ // PhysRegUsed - Keep track of whether the physical register has been used
+ // after its last definition. This is local property.
bool *PhysRegUsed;
// PhysRegPartUse - Keep track of which instruction was the last partial use
@@ -160,7 +160,7 @@
/// HandlePhysRegKill - Add kills of Reg and its sub-registers to the
/// uses. Pay special attention to the sub-register uses which may come below
/// the last use of the whole register.
- bool HandlePhysRegKill(unsigned Reg, MachineInstr *MI,
+ bool HandlePhysRegKill(unsigned Reg, const MachineInstr *MI,
SmallSet<unsigned, 4> &SubKills);
bool HandlePhysRegKill(unsigned Reg, MachineInstr *MI);
void HandlePhysRegUse(unsigned Reg, MachineInstr *MI);
Modified: llvm/trunk/lib/CodeGen/LiveVariables.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/LiveVariables.cpp?rev=47362&r1=47361&r2=47362&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/LiveVariables.cpp (original)
+++ llvm/trunk/lib/CodeGen/LiveVariables.cpp Wed Feb 20 01:36:31 2008
@@ -148,11 +148,12 @@
WorkList.push_back(*PI);
}
-void LiveVariables::MarkVirtRegAliveInBlock(VarInfo& VRInfo,
+void LiveVariables::MarkVirtRegAliveInBlock(VarInfo &VRInfo,
MachineBasicBlock *DefBlock,
MachineBasicBlock *MBB) {
std::vector<MachineBasicBlock*> WorkList;
MarkVirtRegAliveInBlock(VRInfo, DefBlock, MBB, WorkList);
+
while (!WorkList.empty()) {
MachineBasicBlock *Pred = WorkList.back();
WorkList.pop_back();
@@ -163,7 +164,7 @@
void LiveVariables::HandleVirtRegUse(unsigned reg, MachineBasicBlock *MBB,
MachineInstr *MI) {
- MachineRegisterInfo& MRI = MBB->getParent()->getRegInfo();
+ const MachineRegisterInfo &MRI = MBB->getParent()->getRegInfo();
assert(MRI.getVRegDef(reg) && "Register use before def!");
unsigned BBNum = MBB->getNumber();
@@ -194,7 +195,7 @@
if (!VRInfo.AliveBlocks[BBNum])
VRInfo.Kills.push_back(MI);
- // Update all dominating blocks to mark them known live.
+ // Update all dominating blocks to mark them as "known live".
for (MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(),
E = MBB->pred_end(); PI != E; ++PI)
MarkVirtRegAliveInBlock(VRInfo, MRI.getVRegDef(reg)->getParent(), *PI);
@@ -256,49 +257,70 @@
}
}
-bool LiveVariables::HandlePhysRegKill(unsigned Reg, MachineInstr *RefMI,
- SmallSet<unsigned, 4> &SubKills) {
+/// addRegisterKills - For all of a register's sub-registers that are killed in
+/// other instructions (?), indicate that they are killed in this machine
+/// instruction by marking the operand as "killed". (If the machine operand
+/// isn't found, add it first.)
+void LiveVariables::addRegisterKills(unsigned Reg, MachineInstr *MI,
+ SmallSet<unsigned, 4> &SubKills) {
+ if (SubKills.count(Reg) == 0) {
+ MI->addRegisterKilled(Reg, RegInfo, true);
+ return;
+ }
+
for (const unsigned *SubRegs = RegInfo->getImmediateSubRegisters(Reg);
- unsigned SubReg = *SubRegs; ++SubRegs) {
- MachineInstr *LastRef = PhysRegInfo[SubReg];
+ unsigned SubReg = *SubRegs; ++SubRegs)
+ addRegisterKills(SubReg, MI, SubKills);
+}
+
+/// HandlePhysRegKill - The recursive version of HandlePhysRegKill. Returns true
+/// if:
+///
+/// - The register has no sub-registers and the machine instruction is the
+/// last def/use of the register, or
+/// - The register has sub-registers and none of them are killed elsewhere.
+///
+bool LiveVariables::HandlePhysRegKill(unsigned Reg, const MachineInstr *RefMI,
+ SmallSet<unsigned, 4> &SubKills) {
+ const unsigned *SubRegs = RegInfo->getImmediateSubRegisters(Reg);
+
+ for (; unsigned SubReg = *SubRegs; ++SubRegs) {
+ const MachineInstr *LastRef = PhysRegInfo[SubReg];
+
if (LastRef != RefMI ||
!HandlePhysRegKill(SubReg, RefMI, SubKills))
SubKills.insert(SubReg);
}
- if (*RegInfo->getImmediateSubRegisters(Reg) == 0) {
+ if (*SubRegs == 0) {
// No sub-registers, just check if reg is killed by RefMI.
if (PhysRegInfo[Reg] == RefMI)
return true;
- } else if (SubKills.empty())
- // None of the sub-registers are killed elsewhere...
+ } else if (SubKills.empty()) {
+ // None of the sub-registers are killed elsewhere.
return true;
- return false;
-}
-
-void LiveVariables::addRegisterKills(unsigned Reg, MachineInstr *MI,
- SmallSet<unsigned, 4> &SubKills) {
- if (SubKills.count(Reg) == 0)
- MI->addRegisterKilled(Reg, RegInfo, true);
- else {
- for (const unsigned *SubRegs = RegInfo->getImmediateSubRegisters(Reg);
- unsigned SubReg = *SubRegs; ++SubRegs)
- addRegisterKills(SubReg, MI, SubKills);
}
+
+ return false;
}
+/// HandlePhysRegKill - Calls the recursive version of HandlePhysRegKill. (See
+/// above for details.)
bool LiveVariables::HandlePhysRegKill(unsigned Reg, MachineInstr *RefMI) {
SmallSet<unsigned, 4> SubKills;
+
if (HandlePhysRegKill(Reg, RefMI, SubKills)) {
+ // This machine instruction kills this register.
RefMI->addRegisterKilled(Reg, RegInfo, true);
return true;
- } else {
- // Some sub-registers are killed by another MI.
- for (const unsigned *SubRegs = RegInfo->getImmediateSubRegisters(Reg);
- unsigned SubReg = *SubRegs; ++SubRegs)
- addRegisterKills(SubReg, RefMI, SubKills);
- return false;
}
+
+ // Some sub-registers are killed by another machine instruction.
+ for (const unsigned *SubRegs = RegInfo->getImmediateSubRegisters(Reg);
+ unsigned SubReg = *SubRegs; ++SubRegs)
+ addRegisterKills(SubReg, RefMI, SubKills);
+
+ return false;
}
void LiveVariables::HandlePhysRegDef(unsigned Reg, MachineInstr *MI) {
@@ -309,13 +331,14 @@
if (PhysRegPartUse[Reg])
PhysRegPartUse[Reg]->addRegisterKilled(Reg, RegInfo, true);
}
- } else if (PhysRegPartUse[Reg])
+ } else if (PhysRegPartUse[Reg]) {
// Add implicit use / kill to last partial use.
PhysRegPartUse[Reg]->addRegisterKilled(Reg, RegInfo, true);
- else if (LastRef != MI)
+ } else if (LastRef != MI) {
// Defined, but not used. However, watch out for cases where a super-reg
// is also defined on the same MI.
LastRef->addRegisterDead(Reg, RegInfo);
+ }
}
for (const unsigned *SubRegs = RegInfo->getSubRegisters(Reg);
@@ -326,12 +349,13 @@
if (PhysRegPartUse[SubReg])
PhysRegPartUse[SubReg]->addRegisterKilled(SubReg, RegInfo, true);
}
- } else if (PhysRegPartUse[SubReg])
+ } else if (PhysRegPartUse[SubReg]) {
// Add implicit use / kill to last use of a sub-register.
PhysRegPartUse[SubReg]->addRegisterKilled(SubReg, RegInfo, true);
- else if (LastRef != MI)
+ } else if (LastRef != MI) {
// This must be a def of the subreg on the same MI.
LastRef->addRegisterDead(SubReg, RegInfo);
+ }
}
}
@@ -360,6 +384,7 @@
PhysRegUsed[Reg] = false;
PhysRegPartDef[Reg].clear();
PhysRegPartUse[Reg] = NULL;
+
for (const unsigned *SubRegs = RegInfo->getSubRegisters(Reg);
unsigned SubReg = *SubRegs; ++SubRegs) {
PhysRegInfo[SubReg] = MI;
@@ -429,8 +454,10 @@
// Process all uses...
for (unsigned i = 0; i != NumOperandsToProcess; ++i) {
const MachineOperand &MO = MI->getOperand(i);
+
if (MO.isRegister() && MO.isUse() && MO.getReg()) {
unsigned MOReg = MO.getReg();
+
if (TargetRegisterInfo::isVirtualRegister(MOReg))
HandleVirtRegUse(MOReg, MBB, MI);
else if (TargetRegisterInfo::isPhysicalRegister(MOReg) &&
@@ -442,8 +469,10 @@
// Process all defs...
for (unsigned i = 0; i != NumOperandsToProcess; ++i) {
const MachineOperand &MO = MI->getOperand(i);
+
if (MO.isRegister() && MO.isDef() && MO.getReg()) {
unsigned MOReg = MO.getReg();
+
if (TargetRegisterInfo::isVirtualRegister(MOReg)) {
VarInfo &VRInfo = getVarInfo(MOReg);
@@ -466,23 +495,24 @@
SmallVector<unsigned, 4>& VarInfoVec = PHIVarInfo[MBB->getNumber()];
for (SmallVector<unsigned, 4>::iterator I = VarInfoVec.begin(),
- E = VarInfoVec.end(); I != E; ++I) {
- // Only mark it alive only in the block we are representing.
+ 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.
if (!MBB->empty() && MBB->back().getDesc().isReturn()) {
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-in virtual register!");
HandlePhysRegUse(*I, Ret);
+
// Add live-out registers as implicit uses.
if (Ret->findRegisterUseOperandIdx(*I) == -1)
Ret->addOperand(MachineOperand::CreateReg(*I, false, true));
@@ -498,6 +528,7 @@
// Clear some states between BB's. These are purely local information.
for (unsigned i = 0; i != NumRegs; ++i)
PhysRegPartDef[i].clear();
+
std::fill(PhysRegInfo, PhysRegInfo + NumRegs, (MachineInstr*)0);
std::fill(PhysRegUsed, PhysRegUsed + NumRegs, false);
std::fill(PhysRegPartUse, PhysRegPartUse + NumRegs, (MachineInstr*)0);
@@ -507,17 +538,18 @@
// VirtRegInfo onto MI's.
//
for (unsigned i = 0, e1 = VirtRegInfo.size(); i != e1; ++i)
- for (unsigned j = 0, e2 = VirtRegInfo[i].Kills.size(); j != e2; ++j) {
- if (VirtRegInfo[i].Kills[j] == MRI.getVRegDef(i +
- TargetRegisterInfo::FirstVirtualRegister))
- VirtRegInfo[i].Kills[j]->addRegisterDead(i +
- TargetRegisterInfo::FirstVirtualRegister,
- RegInfo);
+ for (unsigned j = 0, e2 = VirtRegInfo[i].Kills.size(); j != e2; ++j)
+ if (VirtRegInfo[i].Kills[j] ==
+ MRI.getVRegDef(i + TargetRegisterInfo::FirstVirtualRegister))
+ VirtRegInfo[i]
+ .Kills[j]->addRegisterDead(i +
+ TargetRegisterInfo::FirstVirtualRegister,
+ RegInfo);
else
- VirtRegInfo[i].Kills[j]->addRegisterKilled(i +
- TargetRegisterInfo::FirstVirtualRegister,
- RegInfo);
- }
+ VirtRegInfo[i]
+ .Kills[j]->addRegisterKilled(i +
+ TargetRegisterInfo::FirstVirtualRegister,
+ RegInfo);
// 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
More information about the llvm-commits
mailing list