#define DEBUG_TYPE "stackslotcoloring"
#include "llvm/CodeGen/Passes.h"
#include "llvm/ADT/BitVector.h"
-#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
#include <vector>
// SSIntervals - Spill slot intervals.
std::vector<LiveInterval*> SSIntervals;
- // SSRefs - Keep a list of frame index references for each spill slot.
- SmallVector<SmallVector<MachineInstr*, 8>, 16> SSRefs;
+ // SSRefs - Keep a list of MachineMemOperands for each spill slot.
+ // MachineMemOperands can be shared between instructions, so we need
+ // to be careful that renames like [FI0, FI1] -> [FI1, FI2] do not
+ // become FI0 -> FI1 -> FI2.
+ SmallVector<SmallVector<MachineMemOperand *, 8>, 16> SSRefs;
// OrigAlignments - Alignments of stack objects before coloring.
SmallVector<unsigned, 16> OrigAlignments;
bool OverlapWithAssignments(LiveInterval *li, int Color) const;
int ColorSlot(LiveInterval *li);
bool ColorSlots(MachineFunction &MF);
- void RewriteInstruction(MachineInstr *MI, int OldFI, int NewFI,
+ void RewriteInstruction(MachineInstr *MI, SmallVectorImpl<int> &SlotMapping,
MachineFunction &MF);
bool RemoveDeadStores(MachineBasicBlock* MBB);
};
for (MachineFunction::iterator MBBI = MF.begin(), E = MF.end();
MBBI != E; ++MBBI) {
MachineBasicBlock *MBB = &*MBBI;
- BlockFrequency Freq = MBFI->getBlockFreq(MBB);
for (MachineBasicBlock::iterator MII = MBB->begin(), EE = MBB->end();
MII != EE; ++MII) {
MachineInstr *MI = &*MII;
continue;
LiveInterval &li = LS->getInterval(FI);
if (!MI->isDebugValue())
- li.weight += LiveIntervals::getSpillWeight(false, true, Freq);
- SSRefs[FI].push_back(MI);
+ li.weight += LiveIntervals::getSpillWeight(false, true, MBFI, MI);
+ }
+ for (MachineInstr::mmo_iterator MMOI = MI->memoperands_begin(),
+ EE = MI->memoperands_end(); MMOI != EE; ++MMOI) {
+ MachineMemOperand *MMO = *MMOI;
+ if (const Value *V = MMO->getValue()) {
+ if (const FixedStackPseudoSourceValue *FSV =
+ dyn_cast<FixedStackPseudoSourceValue>(V)) {
+ int FI = FSV->getFrameIndex();
+ if (FI >= 0)
+ SSRefs[FI].push_back(MMO);
+ }
+ }
}
}
}
/// LiveIntervals that have already been assigned to the specified color.
bool
StackSlotColoring::OverlapWithAssignments(LiveInterval *li, int Color) const {
- const SmallVector<LiveInterval*,4> &OtherLIs = Assignments[Color];
+ const SmallVectorImpl<LiveInterval *> &OtherLIs = Assignments[Color];
for (unsigned i = 0, e = OtherLIs.size(); i != e; ++i) {
LiveInterval *OtherLI = OtherLIs[i];
if (OtherLI->overlaps(*li))
if (!Changed)
return false;
- // Rewrite all MO_FrameIndex operands.
- SmallVector<SmallSet<unsigned, 4>, 4> NewDefs(MF.getNumBlockIDs());
+ // Rewrite all MachineMemOperands.
for (unsigned SS = 0, SE = SSRefs.size(); SS != SE; ++SS) {
int NewFI = SlotMapping[SS];
if (NewFI == -1 || (NewFI == (int)SS))
continue;
- SmallVector<MachineInstr*, 8> &RefMIs = SSRefs[SS];
- for (unsigned i = 0, e = RefMIs.size(); i != e; ++i)
- RewriteInstruction(RefMIs[i], SS, NewFI, MF);
+ const Value *NewSV = PseudoSourceValue::getFixedStack(NewFI);
+ SmallVectorImpl<MachineMemOperand *> &RefMMOs = SSRefs[SS];
+ for (unsigned i = 0, e = RefMMOs.size(); i != e; ++i)
+ RefMMOs[i]->setValue(NewSV);
+ }
+
+ // Rewrite all MO_FrameIndex operands. Look for dead stores.
+ for (MachineFunction::iterator MBBI = MF.begin(), E = MF.end();
+ MBBI != E; ++MBBI) {
+ MachineBasicBlock *MBB = &*MBBI;
+ for (MachineBasicBlock::iterator MII = MBB->begin(), EE = MBB->end();
+ MII != EE; ++MII)
+ RewriteInstruction(MII, SlotMapping, MF);
+ RemoveDeadStores(MBB);
}
// Delete unused stack slots.
/// RewriteInstruction - Rewrite specified instruction by replacing references
/// to old frame index with new one.
-void StackSlotColoring::RewriteInstruction(MachineInstr *MI, int OldFI,
- int NewFI, MachineFunction &MF) {
+void StackSlotColoring::RewriteInstruction(MachineInstr *MI,
+ SmallVectorImpl<int> &SlotMapping,
+ MachineFunction &MF) {
// Update the operands.
for (unsigned i = 0, ee = MI->getNumOperands(); i != ee; ++i) {
MachineOperand &MO = MI->getOperand(i);
if (!MO.isFI())
continue;
- int FI = MO.getIndex();
- if (FI != OldFI)
+ int OldFI = MO.getIndex();
+ if (OldFI < 0)
+ continue;
+ int NewFI = SlotMapping[OldFI];
+ if (NewFI == -1 || NewFI == OldFI)
continue;
MO.setIndex(NewFI);
}
- // 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);
- 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);
+ // The MachineMemOperands have already been updated.
}
if (DCELimit != -1 && (int)NumDead >= DCELimit)
break;
+ int FirstSS, SecondSS;
+ if (TII->isStackSlotCopy(I, FirstSS, SecondSS) &&
+ FirstSS == SecondSS &&
+ FirstSS != -1) {
+ ++NumDead;
+ changed = true;
+ toErase.push_back(I);
+ continue;
+ }
+
MachineBasicBlock::iterator NextMI = llvm::next(I);
if (NextMI == MBB->end()) continue;
- int FirstSS, SecondSS;
unsigned LoadReg = 0;
unsigned StoreReg = 0;
if (!(LoadReg = TII->isLoadFromStackSlot(I, FirstSS))) continue;
++I;
}
- for (SmallVector<MachineInstr*, 4>::iterator I = toErase.begin(),
+ for (SmallVectorImpl<MachineInstr *>::iterator I = toErase.begin(),
E = toErase.end(); I != E; ++I)
(*I)->eraseFromParent();
Assignments[i].clear();
Assignments.clear();
- if (Changed) {
- for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I)
- Changed |= RemoveDeadStores(I);
- }
-
return Changed;
}
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