2008-06-23 21:03:19 +00:00
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//===-- StackSlotColoring.cpp - Stack slot coloring pass. -----------------===//
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2008-06-04 09:18:41 +00:00
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements the stack slot coloring pass.
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//
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//===----------------------------------------------------------------------===//
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#define DEBUG_TYPE "stackcoloring"
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2009-05-03 18:32:42 +00:00
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#include "VirtRegMap.h"
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2008-06-23 21:03:19 +00:00
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#include "llvm/CodeGen/Passes.h"
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2009-05-03 18:32:42 +00:00
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#include "llvm/CodeGen/LiveIntervalAnalysis.h"
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2008-06-04 09:18:41 +00:00
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#include "llvm/CodeGen/LiveStackAnalysis.h"
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#include "llvm/CodeGen/MachineFrameInfo.h"
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2009-05-03 18:32:42 +00:00
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#include "llvm/CodeGen/MachineLoopInfo.h"
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#include "llvm/CodeGen/MachineRegisterInfo.h"
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2008-12-05 05:31:14 +00:00
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#include "llvm/CodeGen/PseudoSourceValue.h"
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2008-06-04 09:18:41 +00:00
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#include "llvm/Support/CommandLine.h"
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#include "llvm/Support/Compiler.h"
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#include "llvm/Support/Debug.h"
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2009-02-20 09:11:36 +00:00
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#include "llvm/Target/TargetInstrInfo.h"
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#include "llvm/Target/TargetMachine.h"
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2008-06-04 09:18:41 +00:00
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#include "llvm/ADT/BitVector.h"
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/ADT/Statistic.h"
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#include <vector>
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using namespace llvm;
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static cl::opt<bool>
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DisableSharing("no-stack-slot-sharing",
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cl::init(false), cl::Hidden,
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2009-02-26 04:47:57 +00:00
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cl::desc("Suppress slot sharing during stack coloring"));
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2009-02-20 09:11:36 +00:00
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2009-05-03 18:32:42 +00:00
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static cl::opt<bool>
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2009-05-03 19:10:11 +00:00
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ColorWithRegs("color-ss-with-regs",
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2009-05-03 18:32:42 +00:00
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cl::init(false), cl::Hidden,
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cl::desc("Color stack slots with free registers"));
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2009-02-24 05:44:18 +00:00
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static cl::opt<int> DCELimit("ssc-dce-limit", cl::init(-1), cl::Hidden);
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2009-05-03 18:32:42 +00:00
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STATISTIC(NumEliminated, "Number of stack slots eliminated due to coloring");
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STATISTIC(NumDead, "Number of trivially dead stack accesses eliminated");
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STATISTIC(NumRegRepl, "Number of stack slot refs replaced with reg refs");
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2008-06-04 09:18:41 +00:00
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namespace {
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class VISIBILITY_HIDDEN StackSlotColoring : public MachineFunctionPass {
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LiveStacks* LS;
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2009-05-03 18:32:42 +00:00
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VirtRegMap* VRM;
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2008-06-04 09:18:41 +00:00
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MachineFrameInfo *MFI;
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2009-05-03 18:32:42 +00:00
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MachineRegisterInfo *MRI;
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2009-02-20 09:11:36 +00:00
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const TargetInstrInfo *TII;
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2009-05-03 18:32:42 +00:00
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const TargetRegisterInfo *TRI;
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const MachineLoopInfo *loopInfo;
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2008-06-04 09:18:41 +00:00
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// SSIntervals - Spill slot intervals.
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std::vector<LiveInterval*> SSIntervals;
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2009-05-03 18:32:42 +00:00
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// SSRefs - Keep a list of frame index references for each spill slot.
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SmallVector<SmallVector<MachineInstr*, 8>, 16> SSRefs;
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2008-06-04 09:18:41 +00:00
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// OrigAlignments - Alignments of stack objects before coloring.
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SmallVector<unsigned, 16> OrigAlignments;
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// OrigSizes - Sizess of stack objects before coloring.
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SmallVector<unsigned, 16> OrigSizes;
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// AllColors - If index is set, it's a spill slot, i.e. color.
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// FIXME: This assumes PEI locate spill slot with smaller indices
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// closest to stack pointer / frame pointer. Therefore, smaller
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// index == better color.
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BitVector AllColors;
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// NextColor - Next "color" that's not yet used.
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int NextColor;
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// UsedColors - "Colors" that have been assigned.
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BitVector UsedColors;
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// Assignments - Color to intervals mapping.
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2009-05-03 18:32:42 +00:00
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SmallVector<SmallVector<LiveInterval*,4>, 16> Assignments;
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2008-06-04 09:18:41 +00:00
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public:
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static char ID; // Pass identification
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2008-09-04 17:05:41 +00:00
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StackSlotColoring() : MachineFunctionPass(&ID), NextColor(-1) {}
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2008-06-04 09:18:41 +00:00
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virtual void getAnalysisUsage(AnalysisUsage &AU) const {
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AU.addRequired<LiveStacks>();
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2009-05-03 18:32:42 +00:00
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AU.addRequired<VirtRegMap>();
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AU.addPreserved<VirtRegMap>();
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AU.addRequired<MachineLoopInfo>();
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AU.addPreserved<MachineLoopInfo>();
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2008-09-22 22:21:38 +00:00
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AU.addPreservedID(MachineDominatorsID);
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2008-06-04 09:18:41 +00:00
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MachineFunctionPass::getAnalysisUsage(AU);
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}
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virtual bool runOnMachineFunction(MachineFunction &MF);
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virtual const char* getPassName() const {
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return "Stack Slot Coloring";
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}
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private:
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2009-05-03 18:32:42 +00:00
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void InitializeSlots();
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void ScanForSpillSlotRefs(MachineFunction &MF);
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2008-06-04 09:18:41 +00:00
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bool OverlapWithAssignments(LiveInterval *li, int Color) const;
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int ColorSlot(LiveInterval *li);
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bool ColorSlots(MachineFunction &MF);
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2009-05-03 18:32:42 +00:00
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bool ColorSlotsWithFreeRegs(SmallVector<int, 16> &SlotMapping,
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SmallVector<SmallVector<int, 4>, 16> &RevMap,
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BitVector &SlotIsReg);
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void RewriteInstruction(MachineInstr *MI, int OldFI, int NewFI,
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MachineFunction &MF);
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void UnfoldAndRewriteInstruction(MachineInstr *MI, int OldFI,
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unsigned Reg, MachineFunction &MF);
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bool AllMemRefsCanBeUnfolded(int SS);
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bool RemoveDeadStores(MachineBasicBlock* MBB);
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2008-06-04 09:18:41 +00:00
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};
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} // end anonymous namespace
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char StackSlotColoring::ID = 0;
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static RegisterPass<StackSlotColoring>
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X("stack-slot-coloring", "Stack Slot Coloring");
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FunctionPass *llvm::createStackSlotColoringPass() {
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return new StackSlotColoring();
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}
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namespace {
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// IntervalSorter - Comparison predicate that sort live intervals by
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// their weight.
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struct IntervalSorter {
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bool operator()(LiveInterval* LHS, LiveInterval* RHS) const {
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return LHS->weight > RHS->weight;
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}
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};
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}
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2009-05-03 18:32:42 +00:00
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/// ScanForSpillSlotRefs - Scan all the machine instructions for spill slot
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/// references and update spill slot weights.
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void StackSlotColoring::ScanForSpillSlotRefs(MachineFunction &MF) {
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SSRefs.resize(MFI->getObjectIndexEnd());
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// FIXME: Need the equivalent of MachineRegisterInfo for frameindex operands.
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for (MachineFunction::iterator MBBI = MF.begin(), E = MF.end();
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MBBI != E; ++MBBI) {
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MachineBasicBlock *MBB = &*MBBI;
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unsigned loopDepth = loopInfo->getLoopDepth(MBB);
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for (MachineBasicBlock::iterator MII = MBB->begin(), EE = MBB->end();
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MII != EE; ++MII) {
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MachineInstr *MI = &*MII;
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for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
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MachineOperand &MO = MI->getOperand(i);
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if (!MO.isFI())
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continue;
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int FI = MO.getIndex();
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if (FI < 0)
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continue;
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if (!LS->hasInterval(FI))
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continue;
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LiveInterval &li = LS->getInterval(FI);
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li.weight += LiveIntervals::getSpillWeight(false, true, loopDepth);
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SSRefs[FI].push_back(MI);
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}
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}
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}
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}
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2008-06-04 09:18:41 +00:00
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/// InitializeSlots - Process all spill stack slot liveintervals and add them
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/// to a sorted (by weight) list.
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2009-05-03 18:32:42 +00:00
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void StackSlotColoring::InitializeSlots() {
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2008-06-04 09:18:41 +00:00
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int LastFI = MFI->getObjectIndexEnd();
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OrigAlignments.resize(LastFI);
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OrigSizes.resize(LastFI);
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AllColors.resize(LastFI);
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UsedColors.resize(LastFI);
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Assignments.resize(LastFI);
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// Gather all spill slots into a list.
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2009-05-03 18:32:42 +00:00
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DOUT << "Spill slot intervals:\n";
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2008-06-04 09:18:41 +00:00
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for (LiveStacks::iterator i = LS->begin(), e = LS->end(); i != e; ++i) {
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LiveInterval &li = i->second;
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2009-05-03 18:32:42 +00:00
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DEBUG(li.dump());
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2008-06-04 09:18:41 +00:00
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int FI = li.getStackSlotIndex();
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if (MFI->isDeadObjectIndex(FI))
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continue;
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SSIntervals.push_back(&li);
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OrigAlignments[FI] = MFI->getObjectAlignment(FI);
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OrigSizes[FI] = MFI->getObjectSize(FI);
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AllColors.set(FI);
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}
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2009-05-03 18:32:42 +00:00
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DOUT << '\n';
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2008-06-04 09:18:41 +00:00
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// Sort them by weight.
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std::stable_sort(SSIntervals.begin(), SSIntervals.end(), IntervalSorter());
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// Get first "color".
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NextColor = AllColors.find_first();
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}
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/// OverlapWithAssignments - Return true if LiveInterval overlaps with any
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/// LiveIntervals that have already been assigned to the specified color.
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bool
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StackSlotColoring::OverlapWithAssignments(LiveInterval *li, int Color) const {
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const SmallVector<LiveInterval*,4> &OtherLIs = Assignments[Color];
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for (unsigned i = 0, e = OtherLIs.size(); i != e; ++i) {
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LiveInterval *OtherLI = OtherLIs[i];
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if (OtherLI->overlaps(*li))
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return true;
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}
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return false;
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}
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2009-05-03 18:32:42 +00:00
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/// ColorSlotsWithFreeRegs - If there are any free registers available, try
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/// replacing spill slots references with registers instead.
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bool
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StackSlotColoring::ColorSlotsWithFreeRegs(SmallVector<int, 16> &SlotMapping,
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SmallVector<SmallVector<int, 4>, 16> &RevMap,
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BitVector &SlotIsReg) {
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if (!ColorWithRegs || !VRM->HasUnusedRegisters())
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return false;
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bool Changed = false;
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DOUT << "Assigning unused registers to spill slots:\n";
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for (unsigned i = 0, e = SSIntervals.size(); i != e; ++i) {
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LiveInterval *li = SSIntervals[i];
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int SS = li->getStackSlotIndex();
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if (!UsedColors[SS])
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continue;
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// Get the largest common sub- register class of all the stack slots that
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// are colored to this stack slot.
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const TargetRegisterClass *RC = 0;
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for (unsigned j = 0, ee = RevMap[SS].size(); j != ee; ++j) {
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int RSS = RevMap[SS][j];
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const TargetRegisterClass *RRC = LS->getIntervalRegClass(RSS);
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if (!RC)
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RC = RRC;
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else
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RC = getCommonSubClass(RC, RRC);
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}
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// If it's not colored to another stack slot, try coloring it
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// to a "free" register.
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if (!RC)
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continue;
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unsigned Reg = VRM->getFirstUnusedRegister(RC);
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if (!Reg)
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continue;
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bool IsSafe = true;
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for (unsigned j = 0, ee = RevMap[SS].size(); j != ee; ++j) {
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int RSS = RevMap[SS][j];
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if (!AllMemRefsCanBeUnfolded(RSS)) {
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IsSafe = false;
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break;
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}
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}
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if (!IsSafe)
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// Try color the next spill slot.
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continue;
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DOUT << "Assigning fi#" << SS << " to " << TRI->getName(Reg)
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<< ", which in turn means...\n";
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// Register and its sub-registers are no longer free.
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VRM->setRegisterUsed(Reg);
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// If reg is a callee-saved register, it will have to be spilled in
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// the prologue.
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MRI->setPhysRegUsed(Reg);
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for (const unsigned *AS = TRI->getAliasSet(Reg); *AS; ++AS) {
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VRM->setRegisterUsed(*AS);
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MRI->setPhysRegUsed(*AS);
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}
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// This spill slot is dead after the rewrites
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MFI->RemoveStackObject(SS);
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// Remember all these FI references will have to be unfolded.
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for (unsigned j = 0, ee = RevMap[SS].size(); j != ee; ++j) {
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int RSS = RevMap[SS][j];
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DOUT << " Assigning fi#" << RSS << " to " << TRI->getName(Reg) << '\n';
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SlotMapping[RSS] = Reg;
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SlotIsReg.set(RSS);
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}
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++NumEliminated;
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Changed = true;
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}
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DOUT << '\n';
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return Changed;
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}
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2008-06-04 09:18:41 +00:00
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/// ColorSlot - Assign a "color" (stack slot) to the specified stack slot.
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///
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int StackSlotColoring::ColorSlot(LiveInterval *li) {
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int Color = -1;
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bool Share = false;
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2008-06-23 21:24:32 +00:00
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if (!DisableSharing) {
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2008-06-04 09:18:41 +00:00
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// Check if it's possible to reuse any of the used colors.
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Color = UsedColors.find_first();
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while (Color != -1) {
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if (!OverlapWithAssignments(li, Color)) {
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Share = true;
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++NumEliminated;
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break;
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}
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Color = UsedColors.find_next(Color);
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}
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}
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// Assign it to the first available color (assumed to be the best) if it's
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// not possible to share a used color with other objects.
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if (!Share) {
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assert(NextColor != -1 && "No more spill slots?");
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Color = NextColor;
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UsedColors.set(Color);
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NextColor = AllColors.find_next(NextColor);
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}
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// Record the assignment.
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Assignments[Color].push_back(li);
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int FI = li->getStackSlotIndex();
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2008-10-15 02:57:38 +00:00
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DOUT << "Assigning fi#" << FI << " to fi#" << Color << "\n";
|
2008-06-04 09:18:41 +00:00
|
|
|
|
|
|
|
// Change size and alignment of the allocated slot. If there are multiple
|
|
|
|
// objects sharing the same slot, then make sure the size and alignment
|
|
|
|
// are large enough for all.
|
|
|
|
unsigned Align = OrigAlignments[FI];
|
|
|
|
if (!Share || Align > MFI->getObjectAlignment(Color))
|
|
|
|
MFI->setObjectAlignment(Color, Align);
|
|
|
|
int64_t Size = OrigSizes[FI];
|
|
|
|
if (!Share || Size > MFI->getObjectSize(Color))
|
|
|
|
MFI->setObjectSize(Color, Size);
|
|
|
|
return Color;
|
|
|
|
}
|
|
|
|
|
|
|
|
/// Colorslots - Color all spill stack slots and rewrite all frameindex machine
|
|
|
|
/// operands in the function.
|
|
|
|
bool StackSlotColoring::ColorSlots(MachineFunction &MF) {
|
|
|
|
unsigned NumObjs = MFI->getObjectIndexEnd();
|
2009-05-03 18:32:42 +00:00
|
|
|
SmallVector<int, 16> SlotMapping(NumObjs, -1);
|
|
|
|
SmallVector<float, 16> SlotWeights(NumObjs, 0.0);
|
|
|
|
SmallVector<SmallVector<int, 4>, 16> RevMap(NumObjs);
|
|
|
|
BitVector SlotIsReg(NumObjs);
|
|
|
|
BitVector UsedColors(NumObjs);
|
2008-06-04 09:18:41 +00:00
|
|
|
|
2009-05-03 18:32:42 +00:00
|
|
|
DOUT << "Color spill slot intervals:\n";
|
2008-06-04 09:18:41 +00:00
|
|
|
bool Changed = false;
|
|
|
|
for (unsigned i = 0, e = SSIntervals.size(); i != e; ++i) {
|
|
|
|
LiveInterval *li = SSIntervals[i];
|
|
|
|
int SS = li->getStackSlotIndex();
|
|
|
|
int NewSS = ColorSlot(li);
|
2009-05-03 18:32:42 +00:00
|
|
|
assert(NewSS >= 0 && "Stack coloring failed?");
|
2008-06-04 09:18:41 +00:00
|
|
|
SlotMapping[SS] = NewSS;
|
2009-05-03 18:32:42 +00:00
|
|
|
RevMap[NewSS].push_back(SS);
|
|
|
|
SlotWeights[NewSS] += li->weight;
|
|
|
|
UsedColors.set(NewSS);
|
2008-06-04 09:18:41 +00:00
|
|
|
Changed |= (SS != NewSS);
|
|
|
|
}
|
|
|
|
|
2009-05-03 18:32:42 +00:00
|
|
|
DOUT << "\nSpill slots after coloring:\n";
|
|
|
|
for (unsigned i = 0, e = SSIntervals.size(); i != e; ++i) {
|
|
|
|
LiveInterval *li = SSIntervals[i];
|
|
|
|
int SS = li->getStackSlotIndex();
|
|
|
|
li->weight = SlotWeights[SS];
|
|
|
|
}
|
|
|
|
// Sort them by new weight.
|
|
|
|
std::stable_sort(SSIntervals.begin(), SSIntervals.end(), IntervalSorter());
|
|
|
|
|
|
|
|
#ifndef NDEBUG
|
|
|
|
for (unsigned i = 0, e = SSIntervals.size(); i != e; ++i)
|
|
|
|
DEBUG(SSIntervals[i]->dump());
|
|
|
|
DOUT << '\n';
|
|
|
|
#endif
|
|
|
|
|
|
|
|
// Can we "color" a stack slot with a unused register?
|
|
|
|
Changed |= ColorSlotsWithFreeRegs(SlotMapping, RevMap, SlotIsReg);
|
|
|
|
|
2008-06-04 09:18:41 +00:00
|
|
|
if (!Changed)
|
|
|
|
return false;
|
|
|
|
|
|
|
|
// Rewrite all MO_FrameIndex operands.
|
2009-05-03 18:32:42 +00:00
|
|
|
for (unsigned SS = 0, SE = SSRefs.size(); SS != SE; ++SS) {
|
|
|
|
bool isReg = SlotIsReg[SS];
|
|
|
|
int NewFI = SlotMapping[SS];
|
|
|
|
if (NewFI == -1 || (NewFI == (int)SS && !isReg))
|
|
|
|
continue;
|
|
|
|
|
|
|
|
SmallVector<MachineInstr*, 8> &RefMIs = SSRefs[SS];
|
|
|
|
for (unsigned i = 0, e = RefMIs.size(); i != e; ++i)
|
|
|
|
if (isReg)
|
|
|
|
// Rewrite to use a register instead.
|
|
|
|
UnfoldAndRewriteInstruction(RefMIs[i], SS, NewFI, MF);
|
|
|
|
else
|
|
|
|
RewriteInstruction(RefMIs[i], SS, NewFI, MF);
|
2008-06-04 09:18:41 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
// Delete unused stack slots.
|
|
|
|
while (NextColor != -1) {
|
2008-10-15 02:57:38 +00:00
|
|
|
DOUT << "Removing unused stack object fi#" << NextColor << "\n";
|
2008-06-04 09:18:41 +00:00
|
|
|
MFI->RemoveStackObject(NextColor);
|
|
|
|
NextColor = AllColors.find_next(NextColor);
|
|
|
|
}
|
|
|
|
|
|
|
|
return true;
|
|
|
|
}
|
|
|
|
|
2009-05-03 18:32:42 +00:00
|
|
|
/// AllMemRefsCanBeUnfolded - Return true if all references of the specified
|
|
|
|
/// spill slot index can be unfolded.
|
|
|
|
bool StackSlotColoring::AllMemRefsCanBeUnfolded(int SS) {
|
|
|
|
SmallVector<MachineInstr*, 8> &RefMIs = SSRefs[SS];
|
|
|
|
for (unsigned i = 0, e = RefMIs.size(); i != e; ++i) {
|
|
|
|
MachineInstr *MI = RefMIs[i];
|
|
|
|
if (!TII->getOpcodeAfterMemoryUnfold(MI->getOpcode(), false, false))
|
|
|
|
return false;
|
|
|
|
for (unsigned j = 0, ee = MI->getNumOperands(); j != ee; ++j) {
|
|
|
|
MachineOperand &MO = MI->getOperand(j);
|
|
|
|
if (MO.isFI() && MO.getIndex() != SS)
|
|
|
|
// If it uses another frameindex, we can, currently* unfold it.
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
return true;
|
|
|
|
}
|
|
|
|
|
|
|
|
/// 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) {
|
|
|
|
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)
|
|
|
|
continue;
|
|
|
|
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);
|
|
|
|
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);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/// UnfoldAndRewriteInstruction - Rewrite specified instruction by unfolding
|
|
|
|
/// folded memory references and replacing those references with register
|
|
|
|
/// references instead.
|
|
|
|
void StackSlotColoring::UnfoldAndRewriteInstruction(MachineInstr *MI, int OldFI,
|
|
|
|
unsigned Reg,
|
|
|
|
MachineFunction &MF) {
|
|
|
|
MachineBasicBlock *MBB = MI->getParent();
|
|
|
|
SmallVector<MachineInstr*, 4> NewMIs;
|
|
|
|
bool Success = TII->unfoldMemoryOperand(MF, MI, Reg, false, false, NewMIs);
|
|
|
|
assert(Success && "Failed to unfold!");
|
|
|
|
MBB->insert(MI, NewMIs[0]);
|
|
|
|
MBB->erase(MI);
|
|
|
|
++NumRegRepl;
|
|
|
|
}
|
|
|
|
|
|
|
|
/// RemoveDeadStores - Scan through a basic block and look for loads followed
|
2009-02-20 09:11:36 +00:00
|
|
|
/// by stores. If they're both using the same stack slot, then the store is
|
|
|
|
/// definitely dead. This could obviously be much more aggressive (consider
|
|
|
|
/// pairs with instructions between them), but such extensions might have a
|
|
|
|
/// considerable compile time impact.
|
2009-05-03 18:32:42 +00:00
|
|
|
bool StackSlotColoring::RemoveDeadStores(MachineBasicBlock* MBB) {
|
2009-02-20 09:11:36 +00:00
|
|
|
// FIXME: This could be much more aggressive, but we need to investigate
|
|
|
|
// the compile time impact of doing so.
|
|
|
|
bool changed = false;
|
|
|
|
|
|
|
|
SmallVector<MachineInstr*, 4> toErase;
|
|
|
|
|
|
|
|
for (MachineBasicBlock::iterator I = MBB->begin(), E = MBB->end();
|
|
|
|
I != E; ++I) {
|
2009-05-03 18:32:42 +00:00
|
|
|
if (DCELimit != -1 && (int)NumDead >= DCELimit)
|
2009-02-24 05:44:18 +00:00
|
|
|
break;
|
|
|
|
|
2009-02-20 09:11:36 +00:00
|
|
|
MachineBasicBlock::iterator NextMI = next(I);
|
|
|
|
if (NextMI == MBB->end()) continue;
|
|
|
|
|
|
|
|
int FirstSS, SecondSS;
|
|
|
|
unsigned LoadReg = 0;
|
|
|
|
unsigned StoreReg = 0;
|
|
|
|
if (!(LoadReg = TII->isLoadFromStackSlot(I, FirstSS))) continue;
|
|
|
|
if (!(StoreReg = TII->isStoreToStackSlot(NextMI, SecondSS))) continue;
|
|
|
|
if (FirstSS != SecondSS || LoadReg != StoreReg || FirstSS == -1) continue;
|
|
|
|
|
2009-05-03 18:32:42 +00:00
|
|
|
++NumDead;
|
2009-02-20 09:11:36 +00:00
|
|
|
changed = true;
|
|
|
|
|
|
|
|
if (NextMI->findRegisterUseOperandIdx(LoadReg, true, 0) != -1) {
|
2009-05-03 18:32:42 +00:00
|
|
|
++NumDead;
|
2009-02-20 09:11:36 +00:00
|
|
|
toErase.push_back(I);
|
|
|
|
}
|
|
|
|
|
|
|
|
toErase.push_back(NextMI);
|
|
|
|
++I;
|
|
|
|
}
|
|
|
|
|
|
|
|
for (SmallVector<MachineInstr*, 4>::iterator I = toErase.begin(),
|
|
|
|
E = toErase.end(); I != E; ++I)
|
|
|
|
(*I)->eraseFromParent();
|
|
|
|
|
|
|
|
return changed;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
2008-06-04 09:18:41 +00:00
|
|
|
bool StackSlotColoring::runOnMachineFunction(MachineFunction &MF) {
|
2008-07-10 19:49:32 +00:00
|
|
|
DOUT << "********** Stack Slot Coloring **********\n";
|
2008-06-04 09:18:41 +00:00
|
|
|
|
|
|
|
MFI = MF.getFrameInfo();
|
2009-05-03 18:32:42 +00:00
|
|
|
MRI = &MF.getRegInfo();
|
2009-02-20 09:11:36 +00:00
|
|
|
TII = MF.getTarget().getInstrInfo();
|
2009-05-03 18:32:42 +00:00
|
|
|
TRI = MF.getTarget().getRegisterInfo();
|
2008-06-04 09:18:41 +00:00
|
|
|
LS = &getAnalysis<LiveStacks>();
|
2009-05-03 18:32:42 +00:00
|
|
|
VRM = &getAnalysis<VirtRegMap>();
|
|
|
|
loopInfo = &getAnalysis<MachineLoopInfo>();
|
2008-06-04 09:18:41 +00:00
|
|
|
|
|
|
|
bool Changed = false;
|
2009-05-03 18:32:42 +00:00
|
|
|
|
|
|
|
unsigned NumSlots = LS->getNumIntervals();
|
|
|
|
if (NumSlots < 2) {
|
|
|
|
if (NumSlots == 0 || !VRM->HasUnusedRegisters())
|
|
|
|
// Nothing to do!
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
|
|
|
|
// Gather spill slot references
|
|
|
|
ScanForSpillSlotRefs(MF);
|
|
|
|
InitializeSlots();
|
|
|
|
Changed = ColorSlots(MF);
|
2008-06-04 09:18:41 +00:00
|
|
|
|
|
|
|
NextColor = -1;
|
|
|
|
SSIntervals.clear();
|
2009-05-03 18:32:42 +00:00
|
|
|
for (unsigned i = 0, e = SSRefs.size(); i != e; ++i)
|
|
|
|
SSRefs[i].clear();
|
|
|
|
SSRefs.clear();
|
2008-06-04 09:18:41 +00:00
|
|
|
OrigAlignments.clear();
|
|
|
|
OrigSizes.clear();
|
|
|
|
AllColors.clear();
|
|
|
|
UsedColors.clear();
|
|
|
|
for (unsigned i = 0, e = Assignments.size(); i != e; ++i)
|
|
|
|
Assignments[i].clear();
|
|
|
|
Assignments.clear();
|
|
|
|
|
2009-02-26 04:47:57 +00:00
|
|
|
if (Changed) {
|
2009-02-20 09:11:36 +00:00
|
|
|
for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I)
|
2009-05-03 18:32:42 +00:00
|
|
|
Changed |= RemoveDeadStores(I);
|
2009-02-20 09:11:36 +00:00
|
|
|
}
|
|
|
|
|
2008-06-04 09:18:41 +00:00
|
|
|
return Changed;
|
|
|
|
}
|