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-rw-r--r--lib/CodeGen/StackSlotColoring.cpp75
1 files changed, 43 insertions, 32 deletions
diff --git a/lib/CodeGen/StackSlotColoring.cpp b/lib/CodeGen/StackSlotColoring.cpp
index 5824644..fad0808 100644
--- a/lib/CodeGen/StackSlotColoring.cpp
+++ b/lib/CodeGen/StackSlotColoring.cpp
@@ -18,6 +18,7 @@
#include "llvm/CodeGen/LiveStackAnalysis.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineLoopInfo.h"
+#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/PseudoSourceValue.h"
#include "llvm/Support/CommandLine.h"
@@ -97,6 +98,7 @@ namespace {
MachineFunctionPass(&ID), ColorWithRegs(RegColor), NextColor(-1) {}
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.setPreservesCFG();
AU.addRequired<LiveStacks>();
AU.addRequired<VirtRegMap>();
AU.addPreserved<VirtRegMap>();
@@ -197,7 +199,7 @@ void StackSlotColoring::InitializeSlots() {
Assignments.resize(LastFI);
// Gather all spill slots into a list.
- DOUT << "Spill slot intervals:\n";
+ DEBUG(errs() << "Spill slot intervals:\n");
for (LiveStacks::iterator i = LS->begin(), e = LS->end(); i != e; ++i) {
LiveInterval &li = i->second;
DEBUG(li.dump());
@@ -209,7 +211,7 @@ void StackSlotColoring::InitializeSlots() {
OrigSizes[FI] = MFI->getObjectSize(FI);
AllColors.set(FI);
}
- DOUT << '\n';
+ DEBUG(errs() << '\n');
// Sort them by weight.
std::stable_sort(SSIntervals.begin(), SSIntervals.end(), IntervalSorter());
@@ -241,7 +243,7 @@ StackSlotColoring::ColorSlotsWithFreeRegs(SmallVector<int, 16> &SlotMapping,
return false;
bool Changed = false;
- DOUT << "Assigning unused registers to spill slots:\n";
+ DEBUG(errs() << "Assigning unused registers to spill slots:\n");
for (unsigned i = 0, e = SSIntervals.size(); i != e; ++i) {
LiveInterval *li = SSIntervals[i];
int SS = li->getStackSlotIndex();
@@ -271,7 +273,8 @@ StackSlotColoring::ColorSlotsWithFreeRegs(SmallVector<int, 16> &SlotMapping,
AllColored = false;
continue;
} else {
- DOUT << "Assigning fi#" << RSS << " to " << TRI->getName(Reg) << '\n';
+ DEBUG(errs() << "Assigning fi#" << RSS << " to "
+ << TRI->getName(Reg) << '\n');
ColoredRegs.push_back(Reg);
SlotMapping[RSS] = Reg;
SlotIsReg.set(RSS);
@@ -298,7 +301,7 @@ StackSlotColoring::ColorSlotsWithFreeRegs(SmallVector<int, 16> &SlotMapping,
++NumEliminated;
}
}
- DOUT << '\n';
+ DEBUG(errs() << '\n');
return Changed;
}
@@ -333,7 +336,7 @@ int StackSlotColoring::ColorSlot(LiveInterval *li) {
// Record the assignment.
Assignments[Color].push_back(li);
int FI = li->getStackSlotIndex();
- DOUT << "Assigning fi#" << FI << " to fi#" << Color << "\n";
+ DEBUG(errs() << "Assigning fi#" << FI << " to fi#" << Color << "\n");
// Change size and alignment of the allocated slot. If there are multiple
// objects sharing the same slot, then make sure the size and alignment
@@ -357,7 +360,7 @@ bool StackSlotColoring::ColorSlots(MachineFunction &MF) {
BitVector SlotIsReg(NumObjs);
BitVector UsedColors(NumObjs);
- DOUT << "Color spill slot intervals:\n";
+ DEBUG(errs() << "Color spill slot intervals:\n");
bool Changed = false;
for (unsigned i = 0, e = SSIntervals.size(); i != e; ++i) {
LiveInterval *li = SSIntervals[i];
@@ -371,7 +374,7 @@ bool StackSlotColoring::ColorSlots(MachineFunction &MF) {
Changed |= (SS != NewSS);
}
- DOUT << "\nSpill slots after coloring:\n";
+ DEBUG(errs() << "\nSpill slots after coloring:\n");
for (unsigned i = 0, e = SSIntervals.size(); i != e; ++i) {
LiveInterval *li = SSIntervals[i];
int SS = li->getStackSlotIndex();
@@ -383,7 +386,7 @@ bool StackSlotColoring::ColorSlots(MachineFunction &MF) {
#ifndef NDEBUG
for (unsigned i = 0, e = SSIntervals.size(); i != e; ++i)
DEBUG(SSIntervals[i]->dump());
- DOUT << '\n';
+ DEBUG(errs() << '\n');
#endif
// Can we "color" a stack slot with a unused register?
@@ -415,7 +418,7 @@ bool StackSlotColoring::ColorSlots(MachineFunction &MF) {
// Delete unused stack slots.
while (NextColor != -1) {
- DOUT << "Removing unused stack object fi#" << NextColor << "\n";
+ DEBUG(errs() << "Removing unused stack object fi#" << NextColor << "\n");
MFI->RemoveStackObject(NextColor);
NextColor = AllColors.find_next(NextColor);
}
@@ -449,6 +452,7 @@ bool StackSlotColoring::AllMemRefsCanBeUnfolded(int SS) {
/// to old frame index with new one.
void StackSlotColoring::RewriteInstruction(MachineInstr *MI, int OldFI,
int NewFI, MachineFunction &MF) {
+ // Update the operands.
for (unsigned i = 0, ee = MI->getNumOperands(); i != ee; ++i) {
MachineOperand &MO = MI->getOperand(i);
if (!MO.isFI())
@@ -459,22 +463,15 @@ void StackSlotColoring::RewriteInstruction(MachineInstr *MI, int OldFI,
MO.setIndex(NewFI);
}
- // Update the MachineMemOperand for the new memory location.
- // FIXME: We need a better method of managing these too.
- SmallVector<MachineMemOperand, 2> MMOs(MI->memoperands_begin(),
- MI->memoperands_end());
- MI->clearMemOperands(MF);
+ // Update the memory references. This changes the MachineMemOperands
+ // directly. They may be in use by multiple instructions, however all
+ // instructions using OldFI are being rewritten to use NewFI.
const Value *OldSV = PseudoSourceValue::getFixedStack(OldFI);
- for (unsigned i = 0, ee = MMOs.size(); i != ee; ++i) {
- if (MMOs[i].getValue() != OldSV)
- MI->addMemOperand(MF, MMOs[i]);
- else {
- MachineMemOperand MMO(PseudoSourceValue::getFixedStack(NewFI),
- MMOs[i].getFlags(), MMOs[i].getOffset(),
- MMOs[i].getSize(), MMOs[i].getAlignment());
- MI->addMemOperand(MF, MMO);
- }
- }
+ const Value *NewSV = PseudoSourceValue::getFixedStack(NewFI);
+ for (MachineInstr::mmo_iterator I = MI->memoperands_begin(),
+ E = MI->memoperands_end(); I != E; ++I)
+ if ((*I)->getValue() == OldSV)
+ (*I)->setValue(NewSV);
}
/// PropagateBackward - Traverse backward and look for the definition of
@@ -503,7 +500,16 @@ bool StackSlotColoring::PropagateBackward(MachineBasicBlock::iterator MII,
if (Reg == OldReg) {
if (MO.isImplicit())
return false;
- const TargetRegisterClass *RC = getInstrOperandRegClass(TRI, TID, i);
+
+ // Abort the use is actually a sub-register def. We don't have enough
+ // information to figure out if it is really legal.
+ if (MO.getSubReg() ||
+ TID.getOpcode() == TargetInstrInfo::EXTRACT_SUBREG ||
+ TID.getOpcode() == TargetInstrInfo::INSERT_SUBREG ||
+ TID.getOpcode() == TargetInstrInfo::SUBREG_TO_REG)
+ return false;
+
+ const TargetRegisterClass *RC = TID.OpInfo[i].getRegClass(TRI);
if (RC && !RC->contains(NewReg))
return false;
@@ -547,7 +553,6 @@ bool StackSlotColoring::PropagateForward(MachineBasicBlock::iterator MII,
SmallVector<MachineOperand*, 4> Uses;
while (++MII != MBB->end()) {
- bool FoundUse = false;
bool FoundKill = false;
const TargetInstrDesc &TID = MII->getDesc();
for (unsigned i = 0, e = MII->getNumOperands(); i != e; ++i) {
@@ -561,12 +566,18 @@ bool StackSlotColoring::PropagateForward(MachineBasicBlock::iterator MII,
if (MO.isDef() || MO.isImplicit())
return false;
- const TargetRegisterClass *RC = getInstrOperandRegClass(TRI, TID, i);
+ // Abort the use is actually a sub-register use. We don't have enough
+ // information to figure out if it is really legal.
+ if (MO.getSubReg() ||
+ TID.getOpcode() == TargetInstrInfo::EXTRACT_SUBREG)
+ return false;
+
+ const TargetRegisterClass *RC = TID.OpInfo[i].getRegClass(TRI);
if (RC && !RC->contains(NewReg))
return false;
- FoundUse = true;
if (MO.isKill())
FoundKill = true;
+
Uses.push_back(&MO);
} else if (TRI->regsOverlap(Reg, NewReg) ||
TRI->regsOverlap(Reg, OldReg))
@@ -593,7 +604,7 @@ StackSlotColoring::UnfoldAndRewriteInstruction(MachineInstr *MI, int OldFI,
MachineBasicBlock *MBB = MI->getParent();
if (unsigned DstReg = TII->isLoadFromStackSlot(MI, OldFI)) {
if (PropagateForward(MI, MBB, DstReg, Reg)) {
- DOUT << "Eliminated load: ";
+ DEBUG(errs() << "Eliminated load: ");
DEBUG(MI->dump());
++NumLoadElim;
} else {
@@ -609,7 +620,7 @@ StackSlotColoring::UnfoldAndRewriteInstruction(MachineInstr *MI, int OldFI,
}
} else if (unsigned SrcReg = TII->isStoreToStackSlot(MI, OldFI)) {
if (MI->killsRegister(SrcReg) && PropagateBackward(MI, MBB, SrcReg, Reg)) {
- DOUT << "Eliminated store: ";
+ DEBUG(errs() << "Eliminated store: ");
DEBUG(MI->dump());
++NumStoreElim;
} else {
@@ -687,7 +698,7 @@ bool StackSlotColoring::RemoveDeadStores(MachineBasicBlock* MBB) {
bool StackSlotColoring::runOnMachineFunction(MachineFunction &MF) {
- DOUT << "********** Stack Slot Coloring **********\n";
+ DEBUG(errs() << "********** Stack Slot Coloring **********\n");
MFI = MF.getFrameInfo();
MRI = &MF.getRegInfo();
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