//
// The LLVM Compiler Infrastructure
//
-// This file was developed by Duraid Madina and is distributed under the
-// University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
-#include "llvm/CodeGen/SSARegMap.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/LiveVariables.h"
#include "llvm/CodeGen/RegAllocRegistry.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/ADT/IndexedMap.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/Statistic.h"
#include <algorithm>
using namespace llvm;
STATISTIC(NumLoads , "Number of loads added");
STATISTIC(NumFolded, "Number of loads/stores folded into instructions");
-namespace {
- static RegisterRegAlloc
- bigBlockRegAlloc("bigblock", " Big-block register allocator",
- createBigBlockRegisterAllocator);
+static RegisterRegAlloc
+ bigBlockRegAlloc("bigblock", " Big-block register allocator",
+ createBigBlockRegisterAllocator);
+namespace {
/// VRegKeyInfo - Defines magic values required to use VirtRegs as DenseMap
/// keys.
struct VRegKeyInfo {
static inline unsigned getEmptyKey() { return -1U; }
static inline unsigned getTombstoneKey() { return -2U; }
+ static bool isEqual(unsigned LHS, unsigned RHS) { return LHS == RHS; }
static unsigned getHashValue(const unsigned &Key) { return Key; }
};
/// RegInfo - For dealing with machine register info (aliases, folds
/// etc)
- const MRegisterInfo *RegInfo;
-
- /// LV - Our generic LiveVariables pointer
- ///
- LiveVariables *LV;
+ const TargetRegisterInfo *RegInfo;
typedef SmallVector<unsigned, 2> VRegTimes;
/// markVirtRegModified - Lets us flip bits in the VirtRegModified bitset
///
void markVirtRegModified(unsigned Reg, bool Val = true) {
- assert(MRegisterInfo::isVirtualRegister(Reg) && "Illegal VirtReg!");
- Reg -= MRegisterInfo::FirstVirtualRegister;
+ assert(TargetRegisterInfo::isVirtualRegister(Reg) && "Illegal VirtReg!");
+ Reg -= TargetRegisterInfo::FirstVirtualRegister;
if (VirtRegModified.size() <= Reg)
VirtRegModified.resize(Reg+1);
VirtRegModified[Reg] = Val;
/// isVirtRegModified - Lets us query the VirtRegModified bitset
///
bool isVirtRegModified(unsigned Reg) const {
- assert(MRegisterInfo::isVirtualRegister(Reg) && "Illegal VirtReg!");
- assert(Reg - MRegisterInfo::FirstVirtualRegister < VirtRegModified.size()
+ assert(TargetRegisterInfo::isVirtualRegister(Reg) && "Illegal VirtReg!");
+ assert(Reg - TargetRegisterInfo::FirstVirtualRegister < VirtRegModified.size()
&& "Illegal virtual register!");
- return VirtRegModified[Reg - MRegisterInfo::FirstVirtualRegister];
+ return VirtRegModified[Reg - TargetRegisterInfo::FirstVirtualRegister];
}
public:
/// getAnalaysisUsage - declares the required analyses
///
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.addRequired<LiveVariables>();
AU.addRequiredID(PHIEliminationID);
AU.addRequiredID(TwoAddressInstructionPassID);
MachineFunctionPass::getAnalysisUsage(AU);
///
void assignVirtToPhysReg(unsigned VirtReg, unsigned PhysReg);
- /// liberatePhysReg - Make sure the specified physical register is available
- /// for use. If there is currently a value in it, it is either moved out of
- /// the way or spilled to memory.
- ///
- void liberatePhysReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator &I,
- unsigned PhysReg);
-
/// isPhysRegAvailable - Return true if the specified physical register is
/// free and available for use. This also includes checking to see if
/// aliased registers are all free...
" the intended one.");
DOUT << " Spilling register " << RegInfo->getName(PhysReg)
<< " containing %reg" << VirtReg;
+
+ const TargetInstrInfo* TII = MBB.getParent()->getTarget().getInstrInfo();
+
if (!isVirtRegModified(VirtReg))
DOUT << " which has not been modified, so no store necessary!";
// register. We only need to spill it into its stack slot if it has been
// modified.
if (isVirtRegModified(VirtReg)) {
- const TargetRegisterClass *RC = MF->getSSARegMap()->getRegClass(VirtReg);
+ const TargetRegisterClass *RC = MF->getRegInfo().getRegClass(VirtReg);
int FrameIndex = getStackSpaceFor(VirtReg, RC);
DOUT << " to stack slot #" << FrameIndex;
- RegInfo->storeRegToStackSlot(MBB, I, PhysReg, FrameIndex, RC);
+ TII->storeRegToStackSlot(MBB, I, PhysReg, true, FrameIndex, RC);
++NumStores; // Update statistics
}
*AliasSet; ++AliasSet)
if (PhysRegsUsed[*AliasSet] != -1 && // Spill aliased register.
PhysRegsUsed[*AliasSet] != -2) // If allocatable.
- if (PhysRegsUsed[*AliasSet] == 0) {
- // This must have been a dead def due to something like this:
- // %EAX :=
- // := op %AL
- // No more use of %EAX, %AH, etc.
- // %EAX isn't dead upon definition, but %AH is. However %AH isn't
- // an operand of definition MI so it's not marked as such.
- DOUT << " Register " << RegInfo->getName(*AliasSet)
- << " [%reg" << *AliasSet
- << "] is never used, removing it frame live list\n";
- removePhysReg(*AliasSet);
- } else
+ if (PhysRegsUsed[*AliasSet])
spillVirtReg(MBB, I, PhysRegsUsed[*AliasSet], *AliasSet);
}
}
// not free!
for (const unsigned *AliasSet = RegInfo->getAliasSet(PhysReg);
*AliasSet; ++AliasSet)
- if (PhysRegsUsed[*AliasSet] != -1) // Aliased register in use?
+ if (PhysRegsUsed[*AliasSet] >= 0) // Aliased register in use?
return false; // Can't use this reg then.
return true;
}
}
-/// liberatePhysReg - Make sure the specified physical register is available for
-/// use. If there is currently a value in it, it is either moved out of the way
-/// or spilled to memory.
-///
-void RABigBlock::liberatePhysReg(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &I,
- unsigned PhysReg) {
- spillPhysReg(MBB, I, PhysReg);
-}
-
/// chooseReg - Pick a physical register to hold the specified
/// virtual register by choosing the one whose value will be read
/// furthest in the future.
///
unsigned RABigBlock::chooseReg(MachineBasicBlock &MBB, MachineInstr *I,
unsigned VirtReg) {
- const TargetRegisterClass *RC = MF->getSSARegMap()->getRegClass(VirtReg);
+ const TargetRegisterClass *RC = MF->getRegInfo().getRegClass(VirtReg);
// First check to see if we have a free register of the requested type...
unsigned PhysReg = getFreeReg(RC);
}
}
}
+
+ if(PhysReg == 0) { // ok, now we're desperate. We couldn't choose
+ // a register to spill by looking through the
+ // read timetable, so now we just spill the
+ // first allocatable register we find.
+
+ // for all physical regs in the RC,
+ for(TargetRegisterClass::iterator pReg = RC->begin();
+ pReg != RC->end(); ++pReg) {
+ // if we find a register we can spill
+ if(PhysRegsUsed[*pReg]>=-1)
+ PhysReg = *pReg; // choose it to be spilled
+ }
+ }
- assert(PhysReg && "couldn't grab a register from the table?");
- // TODO: assert that RC->contains(PhysReg) / handle aliased registers
+ assert(PhysReg && "couldn't choose a register to spill :( ");
+ // TODO: assert that RC->contains(PhysReg) / handle aliased registers?
// since we needed to look in the table we need to spill this register.
spillPhysReg(MBB, I, PhysReg);
MachineInstr *RABigBlock::reloadVirtReg(MachineBasicBlock &MBB, MachineInstr *MI,
unsigned OpNum) {
unsigned VirtReg = MI->getOperand(OpNum).getReg();
+ const TargetInstrInfo* TII = MBB.getParent()->getTarget().getInstrInfo();
// If the virtual register is already available in a physical register,
// just update the instruction and return.
// Otherwise, if we have free physical registers available to hold the
// value, use them.
- const TargetRegisterClass *RC = MF->getSSARegMap()->getRegClass(VirtReg);
+ const TargetRegisterClass *RC = MF->getRegInfo().getRegClass(VirtReg);
unsigned PhysReg = getFreeReg(RC);
int FrameIndex = getStackSpaceFor(VirtReg, RC);
assignVirtToPhysReg(VirtReg, PhysReg);
} else { // no free registers available.
// try to fold the spill into the instruction
- if(MachineInstr* FMI = RegInfo->foldMemoryOperand(MI, OpNum, FrameIndex)) {
+ SmallVector<unsigned, 2> Ops;
+ Ops.push_back(OpNum);
+ if(MachineInstr* FMI = TII->foldMemoryOperand(*MF, MI, Ops, FrameIndex)) {
++NumFolded;
- // Since we changed the address of MI, make sure to update live variables
- // to know that the new instruction has the properties of the old one.
- LV->instructionChanged(MI, FMI);
+ FMI->copyKillDeadInfo(MI);
return MBB.insert(MBB.erase(MI), FMI);
}
<< RegInfo->getName(PhysReg) << "\n";
// Add move instruction(s)
- RegInfo->loadRegFromStackSlot(MBB, MI, PhysReg, FrameIndex, RC);
+ TII->loadRegFromStackSlot(MBB, MI, PhysReg, FrameIndex, RC);
++NumLoads; // Update statistics
- MF->setPhysRegUsed(PhysReg);
+ MF->getRegInfo().setPhysRegUsed(PhysReg);
MI->getOperand(OpNum).setReg(PhysReg); // Assign the input register
return MI;
}
MachineOperand& MO = MI->getOperand(i);
// look for vreg reads..
if (MO.isRegister() && !MO.isDef() && MO.getReg() &&
- MRegisterInfo::isVirtualRegister(MO.getReg())) {
+ TargetRegisterInfo::isVirtualRegister(MO.getReg())) {
// ..and add them to the read table.
VRegTimes* &Times = VRegReadTable[MO.getReg()];
if(!VRegReadTable[MO.getReg()]) {
}
}
+/// isReadModWriteImplicitKill - True if this is an implicit kill for a
+/// read/mod/write register, i.e. update partial register.
+static bool isReadModWriteImplicitKill(MachineInstr *MI, unsigned Reg) {
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand& MO = MI->getOperand(i);
+ if (MO.isRegister() && MO.getReg() == Reg && MO.isImplicit() &&
+ MO.isDef() && !MO.isDead())
+ return true;
+ }
+ return false;
+}
+
+/// isReadModWriteImplicitDef - True if this is an implicit def for a
+/// read/mod/write register, i.e. update partial register.
+static bool isReadModWriteImplicitDef(MachineInstr *MI, unsigned Reg) {
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand& MO = MI->getOperand(i);
+ if (MO.isRegister() && MO.getReg() == Reg && MO.isImplicit() &&
+ !MO.isDef() && MO.isKill())
+ return true;
+ }
+ return false;
+}
+
void RABigBlock::AllocateBasicBlock(MachineBasicBlock &MBB) {
// loop over each instruction
// If this is the first basic block in the machine function, add live-in
// registers as active.
if (&MBB == &*MF->begin()) {
- for (MachineFunction::livein_iterator I = MF->livein_begin(),
- E = MF->livein_end(); I != E; ++I) {
+ for (MachineRegisterInfo::livein_iterator
+ I = MF->getRegInfo().livein_begin(),
+ E = MF->getRegInfo().livein_end(); I != E; ++I) {
unsigned Reg = I->first;
- MF->setPhysRegUsed(Reg);
+ MF->getRegInfo().setPhysRegUsed(Reg);
PhysRegsUsed[Reg] = 0; // It is free and reserved now
- for (const unsigned *AliasSet = RegInfo->getAliasSet(Reg);
+ for (const unsigned *AliasSet = RegInfo->getSubRegisters(Reg);
*AliasSet; ++AliasSet) {
if (PhysRegsUsed[*AliasSet] != -2) {
PhysRegsUsed[*AliasSet] = 0; // It is free and reserved now
- MF->setPhysRegUsed(*AliasSet);
+ MF->getRegInfo().setPhysRegUsed(*AliasSet);
}
}
}
while (MII != MBB.end()) {
MachineInstr *MI = MII++;
MBBCurTime++;
- const TargetInstrDescriptor &TID = TII.get(MI->getOpcode());
+ const TargetInstrDesc &TID = MI->getDesc();
DEBUG(DOUT << "\nTime=" << MBBCurTime << " Starting RegAlloc of: " << *MI;
DOUT << " Regs have values: ";
for (unsigned i = 0; i != RegInfo->getNumRegs(); ++i)
SmallVector<unsigned, 8> Kills;
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand& MO = MI->getOperand(i);
- if (MO.isRegister() && MO.isKill())
- Kills.push_back(MO.getReg());
+ if (MO.isRegister() && MO.isKill()) {
+ if (!MO.isImplicit())
+ Kills.push_back(MO.getReg());
+ else if (!isReadModWriteImplicitKill(MI, MO.getReg()))
+ // These are extra physical register kills when a sub-register
+ // is defined (def of a sub-register is a read/mod/write of the
+ // larger registers). Ignore.
+ Kills.push_back(MO.getReg());
+ }
}
// Get the used operands into registers. This has the potential to spill
MachineOperand& MO = MI->getOperand(i);
// here we are looking for only used operands (never def&use)
if (MO.isRegister() && !MO.isDef() && MO.getReg() && !MO.isImplicit() &&
- MRegisterInfo::isVirtualRegister(MO.getReg()))
+ TargetRegisterInfo::isVirtualRegister(MO.getReg()))
MI = reloadVirtReg(MBB, MI, i);
}
for (unsigned i = 0, e = Kills.size(); i != e; ++i) {
unsigned VirtReg = Kills[i];
unsigned PhysReg = VirtReg;
- if (MRegisterInfo::isVirtualRegister(VirtReg)) {
+ if (TargetRegisterInfo::isVirtualRegister(VirtReg)) {
// If the virtual register was never materialized into a register, it
// might not be in the map, but it won't hurt to zero it out anyway.
unsigned &PhysRegSlot = getVirt2PhysRegMapSlot(VirtReg);
} else if (PhysRegsUsed[PhysReg] == -2) {
// Unallocatable register dead, ignore.
continue;
+ } else {
+ assert((!PhysRegsUsed[PhysReg] || PhysRegsUsed[PhysReg] == -1) &&
+ "Silently clearing a virtual register?");
}
if (PhysReg) {
DOUT << " Last use of " << RegInfo->getName(PhysReg)
<< "[%reg" << VirtReg <<"], removing it from live set\n";
removePhysReg(PhysReg);
- for (const unsigned *AliasSet = RegInfo->getAliasSet(PhysReg);
+ for (const unsigned *AliasSet = RegInfo->getSubRegisters(PhysReg);
*AliasSet; ++AliasSet) {
if (PhysRegsUsed[*AliasSet] != -2) {
DOUT << " Last use of "
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand& MO = MI->getOperand(i);
if (MO.isRegister() && MO.isDef() && !MO.isImplicit() && MO.getReg() &&
- MRegisterInfo::isPhysicalRegister(MO.getReg())) {
+ TargetRegisterInfo::isPhysicalRegister(MO.getReg())) {
unsigned Reg = MO.getReg();
if (PhysRegsUsed[Reg] == -2) continue; // Something like ESP.
-
- MF->setPhysRegUsed(Reg);
+ // These are extra physical register defs when a sub-register
+ // is defined (def of a sub-register is a read/mod/write of the
+ // larger registers). Ignore.
+ if (isReadModWriteImplicitDef(MI, MO.getReg())) continue;
+
+ MF->getRegInfo().setPhysRegUsed(Reg);
spillPhysReg(MBB, MI, Reg, true); // Spill any existing value in reg
PhysRegsUsed[Reg] = 0; // It is free and reserved now
- for (const unsigned *AliasSet = RegInfo->getAliasSet(Reg);
+ for (const unsigned *AliasSet = RegInfo->getSubRegisters(Reg);
*AliasSet; ++AliasSet) {
if (PhysRegsUsed[*AliasSet] != -2) {
PhysRegsUsed[*AliasSet] = 0; // It is free and reserved now
- MF->setPhysRegUsed(*AliasSet);
+ MF->getRegInfo().setPhysRegUsed(*AliasSet);
}
}
}
}
// Loop over the implicit defs, spilling them as well.
- if (TID.ImplicitDefs) {
- for (const unsigned *ImplicitDefs = TID.ImplicitDefs;
+ if (TID.getImplicitDefs()) {
+ for (const unsigned *ImplicitDefs = TID.getImplicitDefs();
*ImplicitDefs; ++ImplicitDefs) {
unsigned Reg = *ImplicitDefs;
- bool IsNonAllocatable = PhysRegsUsed[Reg] == -2;
- if (!IsNonAllocatable) {
+ if (PhysRegsUsed[Reg] != -2) {
spillPhysReg(MBB, MI, Reg, true);
PhysRegsUsed[Reg] = 0; // It is free and reserved now
}
- MF->setPhysRegUsed(Reg);
-
- for (const unsigned *AliasSet = RegInfo->getAliasSet(Reg);
+ MF->getRegInfo().setPhysRegUsed(Reg);
+ for (const unsigned *AliasSet = RegInfo->getSubRegisters(Reg);
*AliasSet; ++AliasSet) {
if (PhysRegsUsed[*AliasSet] != -2) {
- if (!IsNonAllocatable) {
- PhysRegsUsed[*AliasSet] = 0; // It is free and reserved now
- }
- MF->setPhysRegUsed(*AliasSet);
+ PhysRegsUsed[*AliasSet] = 0; // It is free and reserved now
+ MF->getRegInfo().setPhysRegUsed(*AliasSet);
}
}
}
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand& MO = MI->getOperand(i);
if (MO.isRegister() && MO.isDef() && MO.getReg() &&
- MRegisterInfo::isVirtualRegister(MO.getReg())) {
+ TargetRegisterInfo::isVirtualRegister(MO.getReg())) {
unsigned DestVirtReg = MO.getReg();
unsigned DestPhysReg;
// If DestVirtReg already has a value, use it.
if (!(DestPhysReg = getVirt2PhysRegMapSlot(DestVirtReg)))
DestPhysReg = chooseReg(MBB, MI, DestVirtReg);
- MF->setPhysRegUsed(DestPhysReg);
+ MF->getRegInfo().setPhysRegUsed(DestPhysReg);
markVirtRegModified(DestVirtReg);
MI->getOperand(i).setReg(DestPhysReg); // Assign the output register
}
for (unsigned i = 0, e = DeadDefs.size(); i != e; ++i) {
unsigned VirtReg = DeadDefs[i];
unsigned PhysReg = VirtReg;
- if (MRegisterInfo::isVirtualRegister(VirtReg)) {
+ if (TargetRegisterInfo::isVirtualRegister(VirtReg)) {
unsigned &PhysRegSlot = getVirt2PhysRegMapSlot(VirtReg);
PhysReg = PhysRegSlot;
assert(PhysReg != 0);
// Finally, if this is a noop copy instruction, zap it.
unsigned SrcReg, DstReg;
- if (TII.isMoveInstr(*MI, SrcReg, DstReg) && SrcReg == DstReg) {
- LV->removeVirtualRegistersKilled(MI);
- LV->removeVirtualRegistersDead(MI);
+ if (TII.isMoveInstr(*MI, SrcReg, DstReg) && SrcReg == DstReg)
MBB.erase(MI);
- }
}
MachineBasicBlock::iterator MI = MBB.getFirstTerminator();
// Spill all physical registers holding virtual registers now.
for (unsigned i = 0, e = RegInfo->getNumRegs(); i != e; ++i)
- if (PhysRegsUsed[i] != -1 && PhysRegsUsed[i] != -2)
+ if (PhysRegsUsed[i] != -1 && PhysRegsUsed[i] != -2) {
if (unsigned VirtReg = PhysRegsUsed[i])
spillVirtReg(MBB, MI, VirtReg, i);
else
removePhysReg(i);
+ }
}
/// runOnMachineFunction - Register allocate the whole function
MF = &Fn;
TM = &Fn.getTarget();
RegInfo = TM->getRegisterInfo();
- LV = &getAnalysis<LiveVariables>();
PhysRegsUsed.assign(RegInfo->getNumRegs(), -1);
// initialize the virtual->physical register map to have a 'null'
// mapping for all virtual registers
- Virt2PhysRegMap.grow(MF->getSSARegMap()->getLastVirtReg());
- StackSlotForVirtReg.grow(MF->getSSARegMap()->getLastVirtReg());
- VirtRegModified.resize(MF->getSSARegMap()->getLastVirtReg() - MRegisterInfo::FirstVirtualRegister + 1,0);
+ Virt2PhysRegMap.grow(MF->getRegInfo().getLastVirtReg());
+ StackSlotForVirtReg.grow(MF->getRegInfo().getLastVirtReg());
+ VirtRegModified.resize(MF->getRegInfo().getLastVirtReg() -
+ TargetRegisterInfo::FirstVirtualRegister + 1, 0);
// Loop over all of the basic blocks, eliminating virtual register references
for (MachineFunction::iterator MBB = Fn.begin(), MBBe = Fn.end();
projects / oota-llvm.git / blobdiff