#include "Splitter.h"
#include "VirtRegMap.h"
#include "VirtRegRewriter.h"
+#include "RegisterCoalescer.h"
#include "llvm/CodeGen/CalcSpillWeights.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/LiveStackAnalysis.h"
#include "llvm/CodeGen/PBQP/Graph.h"
#include "llvm/CodeGen/PBQP/Heuristics/Briggs.h"
#include "llvm/CodeGen/RegAllocRegistry.h"
-#include "llvm/CodeGen/RegisterCoalescer.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetInstrInfo.h"
#include <set>
#include <vector>
-namespace llvm {
-
-using namespace PBQP;
- using namespace PBQP::Heuristics;
+using namespace llvm;
static RegisterRegAlloc
registerPBQPRepAlloc("pbqp", "PBQP register allocator",
- llvm::createPBQPRegisterAllocator);
+ createDefaultPBQPRegisterAllocator);
static cl::opt<bool>
pbqpCoalescing("pbqp-coalescing",
cl::desc("Attempt coalescing during PBQP register allocation."),
cl::init(false), cl::Hidden);
-static cl::opt<bool>
-pbqpBuilder("pbqp-builder",
- cl::desc("Use new builder system."),
- cl::init(false), cl::Hidden);
-
-
static cl::opt<bool>
pbqpPreSplitting("pbqp-pre-splitting",
- cl::desc("Pre-splite before PBQP register allocation."),
+ cl::desc("Pre-split before PBQP register allocation."),
cl::init(false), cl::Hidden);
+namespace {
+
+///
+/// PBQP based allocators solve the register allocation problem by mapping
+/// register allocation problems to Partitioned Boolean Quadratic
+/// Programming problems.
+class RegAllocPBQP : public MachineFunctionPass {
+public:
+
+ static char ID;
+
+ /// Construct a PBQP register allocator.
+ RegAllocPBQP(std::auto_ptr<PBQPBuilder> b, char *cPassID=0)
+ : MachineFunctionPass(ID), builder(b), customPassID(cPassID) {
+ initializeSlotIndexesPass(*PassRegistry::getPassRegistry());
+ initializeLiveIntervalsPass(*PassRegistry::getPassRegistry());
+ initializeRegisterCoalescerPass(*PassRegistry::getPassRegistry());
+ initializeCalculateSpillWeightsPass(*PassRegistry::getPassRegistry());
+ initializeLiveStacksPass(*PassRegistry::getPassRegistry());
+ initializeMachineLoopInfoPass(*PassRegistry::getPassRegistry());
+ initializeLoopSplitterPass(*PassRegistry::getPassRegistry());
+ initializeVirtRegMapPass(*PassRegistry::getPassRegistry());
+ initializeRenderMachineFunctionPass(*PassRegistry::getPassRegistry());
+ }
+
+ /// Return the pass name.
+ virtual const char* getPassName() const {
+ return "PBQP Register Allocator";
+ }
+
+ /// PBQP analysis usage.
+ virtual void getAnalysisUsage(AnalysisUsage &au) const;
+
+ /// Perform register allocation
+ virtual bool runOnMachineFunction(MachineFunction &MF);
+
+private:
+
+ typedef std::map<const LiveInterval*, unsigned> LI2NodeMap;
+ typedef std::vector<const LiveInterval*> Node2LIMap;
+ typedef std::vector<unsigned> AllowedSet;
+ typedef std::vector<AllowedSet> AllowedSetMap;
+ typedef std::pair<unsigned, unsigned> RegPair;
+ typedef std::map<RegPair, PBQP::PBQPNum> CoalesceMap;
+ typedef std::vector<PBQP::Graph::NodeItr> NodeVector;
+ typedef std::set<unsigned> RegSet;
+
+
+ std::auto_ptr<PBQPBuilder> builder;
+
+ char *customPassID;
+
+ MachineFunction *mf;
+ const TargetMachine *tm;
+ const TargetRegisterInfo *tri;
+ const TargetInstrInfo *tii;
+ const MachineLoopInfo *loopInfo;
+ MachineRegisterInfo *mri;
+ RenderMachineFunction *rmf;
+
+ LiveIntervals *lis;
+ LiveStacks *lss;
+ VirtRegMap *vrm;
+
+ RegSet vregsToAlloc, emptyIntervalVRegs;
+
+ /// \brief Finds the initial set of vreg intervals to allocate.
+ void findVRegIntervalsToAlloc();
+
+ /// \brief Adds a stack interval if the given live interval has been
+ /// spilled. Used to support stack slot coloring.
+ void addStackInterval(const LiveInterval *spilled,MachineRegisterInfo* mri);
+
+ /// \brief Given a solved PBQP problem maps this solution back to a register
+ /// assignment.
+ bool mapPBQPToRegAlloc(const PBQPRAProblem &problem,
+ const PBQP::Solution &solution);
+
+ /// \brief Postprocessing before final spilling. Sets basic block "live in"
+ /// variables.
+ void finalizeAlloc() const;
+
+};
+
char RegAllocPBQP::ID = 0;
+} // End anonymous namespace.
+
unsigned PBQPRAProblem::getVRegForNode(PBQP::Graph::ConstNodeItr node) const {
Node2VReg::const_iterator vregItr = node2VReg.find(node);
assert(vregItr != node2VReg.end() && "No vreg for node.");
return allowedSet[option - 1];
}
-std::auto_ptr<PBQPRAProblem> PBQPBuilder::build(
- MachineFunction *mf,
- const LiveIntervals *lis,
- const RegSet &vregs) {
+std::auto_ptr<PBQPRAProblem> PBQPBuilder::build(MachineFunction *mf,
+ const LiveIntervals *lis,
+ const MachineLoopInfo *loopInfo,
+ const RegSet &vregs) {
typedef std::vector<const LiveInterval*> LIVector;
// Compute an initial allowed set for the current vreg.
typedef std::vector<unsigned> VRAllowed;
VRAllowed vrAllowed;
- for (TargetRegisterClass::iterator aoItr = trc->allocation_order_begin(*mf),
- aoEnd = trc->allocation_order_end(*mf);
- aoItr != aoEnd; ++aoItr) {
- unsigned preg = *aoItr;
+ ArrayRef<unsigned> rawOrder = trc->getRawAllocationOrder(*mf);
+ for (unsigned i = 0; i != rawOrder.size(); ++i) {
+ unsigned preg = rawOrder[i];
if (!reservedRegs.test(preg)) {
vrAllowed.push_back(preg);
}
unsigned preg = *pregItr;
const LiveInterval *pregLI = &lis->getInterval(preg);
- if (pregLI->empty())
+ if (pregLI->empty()) {
continue;
+ }
- if (!vregLI->overlaps(*pregLI))
+ if (!vregLI->overlaps(*pregLI)) {
continue;
+ }
// Remove the register from the allowed set.
VRAllowed::iterator eraseItr =
const LiveInterval &l1 = lis->getInterval(vr1);
const PBQPRAProblem::AllowedSet &vr1Allowed = p->getAllowedSet(vr1);
- for (RegSet::iterator vr2Itr = llvm::next(vr1Itr);
+ for (RegSet::const_iterator vr2Itr = llvm::next(vr1Itr);
vr2Itr != vrEnd; ++vr2Itr) {
unsigned vr2 = *vr2Itr;
const LiveInterval &l2 = lis->getInterval(vr2);
costVec[0] = spillCost;
}
-void PBQPBuilder::addInterferenceCosts(PBQP::Matrix &costMat,
- const PBQPRAProblem::AllowedSet &vr1Allowed,
- const PBQPRAProblem::AllowedSet &vr2Allowed,
- const TargetRegisterInfo *tri) {
+void PBQPBuilder::addInterferenceCosts(
+ PBQP::Matrix &costMat,
+ const PBQPRAProblem::AllowedSet &vr1Allowed,
+ const PBQPRAProblem::AllowedSet &vr2Allowed,
+ const TargetRegisterInfo *tri) {
assert(costMat.getRows() == vr1Allowed.size() + 1 && "Matrix height mismatch.");
assert(costMat.getCols() == vr2Allowed.size() + 1 && "Matrix width mismatch.");
- for (unsigned i = 0; i < vr1Allowed.size(); ++i) {
+ for (unsigned i = 0; i != vr1Allowed.size(); ++i) {
unsigned preg1 = vr1Allowed[i];
- for (unsigned j = 0; j < vr2Allowed.size(); ++j) {
+ for (unsigned j = 0; j != vr2Allowed.size(); ++j) {
unsigned preg2 = vr2Allowed[j];
if (tri->regsOverlap(preg1, preg2)) {
}
}
+std::auto_ptr<PBQPRAProblem> PBQPBuilderWithCoalescing::build(
+ MachineFunction *mf,
+ const LiveIntervals *lis,
+ const MachineLoopInfo *loopInfo,
+ const RegSet &vregs) {
+ std::auto_ptr<PBQPRAProblem> p = PBQPBuilder::build(mf, lis, loopInfo, vregs);
+ PBQP::Graph &g = p->getGraph();
-void RegAllocPBQP::getAnalysisUsage(AnalysisUsage &au) const {
- au.addRequired<SlotIndexes>();
- au.addPreserved<SlotIndexes>();
- au.addRequired<LiveIntervals>();
- //au.addRequiredID(SplitCriticalEdgesID);
- au.addRequired<RegisterCoalescer>();
- au.addRequired<CalculateSpillWeights>();
- au.addRequired<LiveStacks>();
- au.addPreserved<LiveStacks>();
- au.addRequired<MachineLoopInfo>();
- au.addPreserved<MachineLoopInfo>();
- if (pbqpPreSplitting)
- au.addRequired<LoopSplitter>();
- au.addRequired<VirtRegMap>();
- au.addRequired<RenderMachineFunction>();
- MachineFunctionPass::getAnalysisUsage(au);
-}
-
-template <typename RegContainer>
-PBQP::Vector RegAllocPBQP::buildCostVector(unsigned vReg,
- const RegContainer &allowed,
- const CoalesceMap &coalesces,
- PBQP::PBQPNum spillCost) const {
-
- typedef typename RegContainer::const_iterator AllowedItr;
-
- // Allocate vector. Additional element (0th) used for spill option
- PBQP::Vector v(allowed.size() + 1, 0);
-
- v[0] = spillCost;
-
- // Iterate over the allowed registers inserting coalesce benefits if there
- // are any.
- unsigned ai = 0;
- for (AllowedItr itr = allowed.begin(), end = allowed.end();
- itr != end; ++itr, ++ai) {
-
- unsigned pReg = *itr;
-
- CoalesceMap::const_iterator cmItr =
- coalesces.find(RegPair(vReg, pReg));
-
- // No coalesce - on to the next preg.
- if (cmItr == coalesces.end())
- continue;
+ const TargetMachine &tm = mf->getTarget();
+ CoalescerPair cp(*tm.getInstrInfo(), *tm.getRegisterInfo());
- // We have a coalesce - insert the benefit.
- v[ai + 1] = -cmItr->second;
- }
+ // Scan the machine function and add a coalescing cost whenever CoalescerPair
+ // gives the Ok.
+ for (MachineFunction::const_iterator mbbItr = mf->begin(),
+ mbbEnd = mf->end();
+ mbbItr != mbbEnd; ++mbbItr) {
+ const MachineBasicBlock *mbb = &*mbbItr;
- return v;
-}
+ for (MachineBasicBlock::const_iterator miItr = mbb->begin(),
+ miEnd = mbb->end();
+ miItr != miEnd; ++miItr) {
+ const MachineInstr *mi = &*miItr;
-template <typename RegContainer>
-PBQP::Matrix* RegAllocPBQP::buildInterferenceMatrix(
- const RegContainer &allowed1, const RegContainer &allowed2) const {
-
- typedef typename RegContainer::const_iterator RegContainerIterator;
-
- // Construct a PBQP matrix representing the cost of allocation options. The
- // rows and columns correspond to the allocation options for the two live
- // intervals. Elements will be infinite where corresponding registers alias,
- // since we cannot allocate aliasing registers to interfering live intervals.
- // All other elements (non-aliasing combinations) will have zero cost. Note
- // that the spill option (element 0,0) has zero cost, since we can allocate
- // both intervals to memory safely (the cost for each individual allocation
- // to memory is accounted for by the cost vectors for each live interval).
- PBQP::Matrix *m =
- new PBQP::Matrix(allowed1.size() + 1, allowed2.size() + 1, 0);
-
- // Assume this is a zero matrix until proven otherwise. Zero matrices occur
- // between interfering live ranges with non-overlapping register sets (e.g.
- // non-overlapping reg classes, or disjoint sets of allowed regs within the
- // same class). The term "overlapping" is used advisedly: sets which do not
- // intersect, but contain registers which alias, will have non-zero matrices.
- // We optimize zero matrices away to improve solver speed.
- bool isZeroMatrix = true;
-
-
- // Row index. Starts at 1, since the 0th row is for the spill option, which
- // is always zero.
- unsigned ri = 1;
-
- // Iterate over allowed sets, insert infinities where required.
- for (RegContainerIterator a1Itr = allowed1.begin(), a1End = allowed1.end();
- a1Itr != a1End; ++a1Itr) {
-
- // Column index, starts at 1 as for row index.
- unsigned ci = 1;
- unsigned reg1 = *a1Itr;
-
- for (RegContainerIterator a2Itr = allowed2.begin(), a2End = allowed2.end();
- a2Itr != a2End; ++a2Itr) {
-
- unsigned reg2 = *a2Itr;
-
- // If the row/column regs are identical or alias insert an infinity.
- if (tri->regsOverlap(reg1, reg2)) {
- (*m)[ri][ci] = std::numeric_limits<PBQP::PBQPNum>::infinity();
- isZeroMatrix = false;
+ if (!cp.setRegisters(mi)) {
+ continue; // Not coalescable.
}
- ++ci;
- }
-
- ++ri;
- }
-
- // If this turns out to be a zero matrix...
- if (isZeroMatrix) {
- // free it and return null.
- delete m;
- return 0;
- }
-
- // ...otherwise return the cost matrix.
- return m;
-}
-
-template <typename RegContainer>
-PBQP::Matrix* RegAllocPBQP::buildCoalescingMatrix(
- const RegContainer &allowed1, const RegContainer &allowed2,
- PBQP::PBQPNum cBenefit) const {
-
- typedef typename RegContainer::const_iterator RegContainerIterator;
-
- // Construct a PBQP Matrix representing the benefits of coalescing. As with
- // interference matrices the rows and columns represent allowed registers
- // for the LiveIntervals which are (potentially) to be coalesced. The amount
- // -cBenefit will be placed in any element representing the same register
- // for both intervals.
- PBQP::Matrix *m =
- new PBQP::Matrix(allowed1.size() + 1, allowed2.size() + 1, 0);
-
- // Reset costs to zero.
- m->reset(0);
-
- // Assume the matrix is zero till proven otherwise. Zero matrices will be
- // optimized away as in the interference case.
- bool isZeroMatrix = true;
-
- // Row index. Starts at 1, since the 0th row is for the spill option, which
- // is always zero.
- unsigned ri = 1;
-
- // Iterate over the allowed sets, insert coalescing benefits where
- // appropriate.
- for (RegContainerIterator a1Itr = allowed1.begin(), a1End = allowed1.end();
- a1Itr != a1End; ++a1Itr) {
-
- // Column index, starts at 1 as for row index.
- unsigned ci = 1;
- unsigned reg1 = *a1Itr;
-
- for (RegContainerIterator a2Itr = allowed2.begin(), a2End = allowed2.end();
- a2Itr != a2End; ++a2Itr) {
-
- // If the row and column represent the same register insert a beneficial
- // cost to preference this allocation - it would allow us to eliminate a
- // move instruction.
- if (reg1 == *a2Itr) {
- (*m)[ri][ci] = -cBenefit;
- isZeroMatrix = false;
+ if (cp.getSrcReg() == cp.getDstReg()) {
+ continue; // Already coalesced.
}
- ++ci;
- }
+ unsigned dst = cp.getDstReg(),
+ src = cp.getSrcReg();
- ++ri;
- }
+ const float copyFactor = 0.5; // Cost of copy relative to load. Current
+ // value plucked randomly out of the air.
+
+ PBQP::PBQPNum cBenefit =
+ copyFactor * LiveIntervals::getSpillWeight(false, true,
+ loopInfo->getLoopDepth(mbb));
- // If this turns out to be a zero matrix...
- if (isZeroMatrix) {
- // ...free it and return null.
- delete m;
- return 0;
- }
-
- return m;
-}
-
-RegAllocPBQP::CoalesceMap RegAllocPBQP::findCoalesces() {
-
- typedef MachineFunction::const_iterator MFIterator;
- typedef MachineBasicBlock::const_iterator MBBIterator;
- typedef LiveInterval::const_vni_iterator VNIIterator;
-
- CoalesceMap coalescesFound;
-
- // To find coalesces we need to iterate over the function looking for
- // copy instructions.
- for (MFIterator bbItr = mf->begin(), bbEnd = mf->end();
- bbItr != bbEnd; ++bbItr) {
-
- const MachineBasicBlock *mbb = &*bbItr;
-
- for (MBBIterator iItr = mbb->begin(), iEnd = mbb->end();
- iItr != iEnd; ++iItr) {
-
- const MachineInstr *instr = &*iItr;
-
- // If this isn't a copy then continue to the next instruction.
- if (!instr->isCopy())
- continue;
-
- unsigned srcReg = instr->getOperand(1).getReg();
- unsigned dstReg = instr->getOperand(0).getReg();
-
- // If the registers are already the same our job is nice and easy.
- if (dstReg == srcReg)
- continue;
-
- bool srcRegIsPhysical = TargetRegisterInfo::isPhysicalRegister(srcReg),
- dstRegIsPhysical = TargetRegisterInfo::isPhysicalRegister(dstReg);
-
- // If both registers are physical then we can't coalesce.
- if (srcRegIsPhysical && dstRegIsPhysical)
- continue;
-
- // If it's a copy that includes two virtual register but the source and
- // destination classes differ then we can't coalesce.
- if (!srcRegIsPhysical && !dstRegIsPhysical &&
- mri->getRegClass(srcReg) != mri->getRegClass(dstReg))
- continue;
-
- // If one is physical and one is virtual, check that the physical is
- // allocatable in the class of the virtual.
- if (srcRegIsPhysical && !dstRegIsPhysical) {
- const TargetRegisterClass *dstRegClass = mri->getRegClass(dstReg);
- if (std::find(dstRegClass->allocation_order_begin(*mf),
- dstRegClass->allocation_order_end(*mf), srcReg) ==
- dstRegClass->allocation_order_end(*mf))
- continue;
- }
- if (!srcRegIsPhysical && dstRegIsPhysical) {
- const TargetRegisterClass *srcRegClass = mri->getRegClass(srcReg);
- if (std::find(srcRegClass->allocation_order_begin(*mf),
- srcRegClass->allocation_order_end(*mf), dstReg) ==
- srcRegClass->allocation_order_end(*mf))
+ if (cp.isPhys()) {
+ if (!lis->isAllocatable(dst)) {
continue;
- }
-
- // If we've made it here we have a copy with compatible register classes.
- // We can probably coalesce, but we need to consider overlap.
- const LiveInterval *srcLI = &lis->getInterval(srcReg),
- *dstLI = &lis->getInterval(dstReg);
-
- if (srcLI->overlaps(*dstLI)) {
- // Even in the case of an overlap we might still be able to coalesce,
- // but we need to make sure that no definition of either range occurs
- // while the other range is live.
-
- // Otherwise start by assuming we're ok.
- bool badDef = false;
-
- // Test all defs of the source range.
- for (VNIIterator
- vniItr = srcLI->vni_begin(), vniEnd = srcLI->vni_end();
- vniItr != vniEnd; ++vniItr) {
-
- // If we find a poorly defined def we err on the side of caution.
- if (!(*vniItr)->def.isValid()) {
- badDef = true;
- break;
- }
+ }
- // If we find a def that kills the coalescing opportunity then
- // record it and break from the loop.
- if (dstLI->liveAt((*vniItr)->def)) {
- badDef = true;
- break;
+ const PBQPRAProblem::AllowedSet &allowed = p->getAllowedSet(src);
+ unsigned pregOpt = 0;
+ while (pregOpt < allowed.size() && allowed[pregOpt] != dst) {
+ ++pregOpt;
+ }
+ if (pregOpt < allowed.size()) {
+ ++pregOpt; // +1 to account for spill option.
+ PBQP::Graph::NodeItr node = p->getNodeForVReg(src);
+ addPhysRegCoalesce(g.getNodeCosts(node), pregOpt, cBenefit);
+ }
+ } else {
+ const PBQPRAProblem::AllowedSet *allowed1 = &p->getAllowedSet(dst);
+ const PBQPRAProblem::AllowedSet *allowed2 = &p->getAllowedSet(src);
+ PBQP::Graph::NodeItr node1 = p->getNodeForVReg(dst);
+ PBQP::Graph::NodeItr node2 = p->getNodeForVReg(src);
+ PBQP::Graph::EdgeItr edge = g.findEdge(node1, node2);
+ if (edge == g.edgesEnd()) {
+ edge = g.addEdge(node1, node2, PBQP::Matrix(allowed1->size() + 1,
+ allowed2->size() + 1,
+ 0));
+ } else {
+ if (g.getEdgeNode1(edge) == node2) {
+ std::swap(node1, node2);
+ std::swap(allowed1, allowed2);
}
}
+
+ addVirtRegCoalesce(g.getEdgeCosts(edge), *allowed1, *allowed2,
+ cBenefit);
+ }
+ }
+ }
- // If we have a bad def give up, continue to the next instruction.
- if (badDef)
- continue;
-
- // Otherwise test definitions of the destination range.
- for (VNIIterator
- vniItr = dstLI->vni_begin(), vniEnd = dstLI->vni_end();
- vniItr != vniEnd; ++vniItr) {
-
- // We want to make sure we skip the copy instruction itself.
- if ((*vniItr)->getCopy() == instr)
- continue;
-
- if (!(*vniItr)->def.isValid()) {
- badDef = true;
- break;
- }
+ return p;
+}
- if (srcLI->liveAt((*vniItr)->def)) {
- badDef = true;
- break;
- }
- }
+void PBQPBuilderWithCoalescing::addPhysRegCoalesce(PBQP::Vector &costVec,
+ unsigned pregOption,
+ PBQP::PBQPNum benefit) {
+ costVec[pregOption] += -benefit;
+}
- // As before a bad def we give up and continue to the next instr.
- if (badDef)
- continue;
- }
+void PBQPBuilderWithCoalescing::addVirtRegCoalesce(
+ PBQP::Matrix &costMat,
+ const PBQPRAProblem::AllowedSet &vr1Allowed,
+ const PBQPRAProblem::AllowedSet &vr2Allowed,
+ PBQP::PBQPNum benefit) {
- // If we make it to here then either the ranges didn't overlap, or they
- // did, but none of their definitions would prevent us from coalescing.
- // We're good to go with the coalesce.
+ assert(costMat.getRows() == vr1Allowed.size() + 1 && "Size mismatch.");
+ assert(costMat.getCols() == vr2Allowed.size() + 1 && "Size mismatch.");
- float cBenefit = std::pow(10.0f, (float)loopInfo->getLoopDepth(mbb)) / 5.0;
+ for (unsigned i = 0; i != vr1Allowed.size(); ++i) {
+ unsigned preg1 = vr1Allowed[i];
+ for (unsigned j = 0; j != vr2Allowed.size(); ++j) {
+ unsigned preg2 = vr2Allowed[j];
- coalescesFound[RegPair(srcReg, dstReg)] = cBenefit;
- coalescesFound[RegPair(dstReg, srcReg)] = cBenefit;
+ if (preg1 == preg2) {
+ costMat[i + 1][j + 1] += -benefit;
+ }
}
-
}
+}
- return coalescesFound;
+
+void RegAllocPBQP::getAnalysisUsage(AnalysisUsage &au) const {
+ au.addRequired<SlotIndexes>();
+ au.addPreserved<SlotIndexes>();
+ au.addRequired<LiveIntervals>();
+ //au.addRequiredID(SplitCriticalEdgesID);
+ au.addRequiredID(RegisterCoalescerPassID);
+ if (customPassID)
+ au.addRequiredID(*customPassID);
+ au.addRequired<CalculateSpillWeights>();
+ au.addRequired<LiveStacks>();
+ au.addPreserved<LiveStacks>();
+ au.addRequired<MachineLoopInfo>();
+ au.addPreserved<MachineLoopInfo>();
+ if (pbqpPreSplitting)
+ au.addRequired<LoopSplitter>();
+ au.addRequired<VirtRegMap>();
+ au.addRequired<RenderMachineFunction>();
+ MachineFunctionPass::getAnalysisUsage(au);
}
void RegAllocPBQP::findVRegIntervalsToAlloc() {
// finalizeAlloc.
if (!li->empty()) {
vregsToAlloc.insert(li->reg);
- }
- else {
+ } else {
emptyIntervalVRegs.insert(li->reg);
}
}
}
-PBQP::Graph RegAllocPBQP::constructPBQPProblem() {
-
- typedef std::vector<const LiveInterval*> LIVector;
- typedef std::vector<unsigned> RegVector;
-
- // This will store the physical intervals for easy reference.
- LIVector physIntervals;
-
- // Start by clearing the old node <-> live interval mappings & allowed sets
- li2Node.clear();
- node2LI.clear();
- allowedSets.clear();
-
- // Populate physIntervals, update preg use:
- for (LiveIntervals::iterator itr = lis->begin(), end = lis->end();
- itr != end; ++itr) {
-
- if (TargetRegisterInfo::isPhysicalRegister(itr->first)) {
- physIntervals.push_back(itr->second);
- mri->setPhysRegUsed(itr->second->reg);
- }
- }
-
- // Iterate over vreg intervals, construct live interval <-> node number
- // mappings.
- for (RegSet::const_iterator itr = vregsToAlloc.begin(),
- end = vregsToAlloc.end();
- itr != end; ++itr) {
- const LiveInterval *li = &lis->getInterval(*itr);
-
- li2Node[li] = node2LI.size();
- node2LI.push_back(li);
- }
-
- // Get the set of potential coalesces.
- CoalesceMap coalesces;
-
- if (pbqpCoalescing) {
- coalesces = findCoalesces();
- }
-
- // Construct a PBQP solver for this problem
- PBQP::Graph problem;
- problemNodes.resize(vregsToAlloc.size());
-
- // Resize allowedSets container appropriately.
- allowedSets.resize(vregsToAlloc.size());
-
- BitVector ReservedRegs = tri->getReservedRegs(*mf);
-
- // Iterate over virtual register intervals to compute allowed sets...
- for (unsigned node = 0; node < node2LI.size(); ++node) {
-
- // Grab pointers to the interval and its register class.
- const LiveInterval *li = node2LI[node];
- const TargetRegisterClass *liRC = mri->getRegClass(li->reg);
-
- // Start by assuming all allocable registers in the class are allowed...
- RegVector liAllowed;
- TargetRegisterClass::iterator aob = liRC->allocation_order_begin(*mf);
- TargetRegisterClass::iterator aoe = liRC->allocation_order_end(*mf);
- for (TargetRegisterClass::iterator it = aob; it != aoe; ++it)
- if (!ReservedRegs.test(*it))
- liAllowed.push_back(*it);
-
- // Eliminate the physical registers which overlap with this range, along
- // with all their aliases.
- for (LIVector::iterator pItr = physIntervals.begin(),
- pEnd = physIntervals.end(); pItr != pEnd; ++pItr) {
-
- if (!li->overlaps(**pItr))
- continue;
-
- unsigned pReg = (*pItr)->reg;
-
- // If we get here then the live intervals overlap, but we're still ok
- // if they're coalescable.
- if (coalesces.find(RegPair(li->reg, pReg)) != coalesces.end()) {
- DEBUG(dbgs() << "CoalescingOverride: (" << li->reg << ", " << pReg << ")\n");
- continue;
- }
-
- // If we get here then we have a genuine exclusion.
-
- // Remove the overlapping reg...
- RegVector::iterator eraseItr =
- std::find(liAllowed.begin(), liAllowed.end(), pReg);
-
- if (eraseItr != liAllowed.end())
- liAllowed.erase(eraseItr);
-
- const unsigned *aliasItr = tri->getAliasSet(pReg);
-
- if (aliasItr != 0) {
- // ...and its aliases.
- for (; *aliasItr != 0; ++aliasItr) {
- RegVector::iterator eraseItr =
- std::find(liAllowed.begin(), liAllowed.end(), *aliasItr);
-
- if (eraseItr != liAllowed.end()) {
- liAllowed.erase(eraseItr);
- }
- }
- }
- }
-
- // Copy the allowed set into a member vector for use when constructing cost
- // vectors & matrices, and mapping PBQP solutions back to assignments.
- allowedSets[node] = AllowedSet(liAllowed.begin(), liAllowed.end());
-
- // Set the spill cost to the interval weight, or epsilon if the
- // interval weight is zero
- PBQP::PBQPNum spillCost = (li->weight != 0.0) ?
- li->weight : std::numeric_limits<PBQP::PBQPNum>::min();
-
- // Build a cost vector for this interval.
- problemNodes[node] =
- problem.addNode(
- buildCostVector(li->reg, allowedSets[node], coalesces, spillCost));
-
- }
-
-
- // Now add the cost matrices...
- for (unsigned node1 = 0; node1 < node2LI.size(); ++node1) {
- const LiveInterval *li = node2LI[node1];
-
- // Test for live range overlaps and insert interference matrices.
- for (unsigned node2 = node1 + 1; node2 < node2LI.size(); ++node2) {
- const LiveInterval *li2 = node2LI[node2];
-
- CoalesceMap::const_iterator cmItr =
- coalesces.find(RegPair(li->reg, li2->reg));
-
- PBQP::Matrix *m = 0;
-
- if (cmItr != coalesces.end()) {
- m = buildCoalescingMatrix(allowedSets[node1], allowedSets[node2],
- cmItr->second);
- }
- else if (li->overlaps(*li2)) {
- m = buildInterferenceMatrix(allowedSets[node1], allowedSets[node2]);
- }
-
- if (m != 0) {
- problem.addEdge(problemNodes[node1],
- problemNodes[node2],
- *m);
-
- delete m;
- }
- }
- }
-
- assert(problem.getNumNodes() == allowedSets.size());
-/*
- std::cerr << "Allocating for " << problem.getNumNodes() << " nodes, "
- << problem.getNumEdges() << " edges.\n";
-
- problem.printDot(std::cerr);
-*/
- // We're done, PBQP problem constructed - return it.
- return problem;
-}
-
void RegAllocPBQP::addStackInterval(const LiveInterval *spilled,
MachineRegisterInfo* mri) {
int stackSlot = vrm->getStackSlot(spilled->reg);
- if (stackSlot == VirtRegMap::NO_STACK_SLOT)
+ if (stackSlot == VirtRegMap::NO_STACK_SLOT) {
return;
+ }
const TargetRegisterClass *RC = mri->getRegClass(spilled->reg);
LiveInterval &stackInterval = lss->getOrCreateInterval(stackSlot, RC);
VNInfo *vni;
- if (stackInterval.getNumValNums() != 0)
+ if (stackInterval.getNumValNums() != 0) {
vni = stackInterval.getValNumInfo(0);
- else
+ } else {
vni = stackInterval.getNextValue(
- SlotIndex(), 0, false, lss->getVNInfoAllocator());
+ SlotIndex(), 0, lss->getVNInfoAllocator());
+ }
LiveInterval &rhsInterval = lis->getInterval(spilled->reg);
stackInterval.MergeRangesInAsValue(rhsInterval, vni);
}
-bool RegAllocPBQP::mapPBQPToRegAlloc(const PBQP::Solution &solution) {
-
- // Set to true if we have any spills
- bool anotherRoundNeeded = false;
-
- // Clear the existing allocation.
- vrm->clearAllVirt();
-
- // Iterate over the nodes mapping the PBQP solution to a register assignment.
- for (unsigned node = 0; node < node2LI.size(); ++node) {
- unsigned virtReg = node2LI[node]->reg,
- allocSelection = solution.getSelection(problemNodes[node]);
-
-
- // If the PBQP solution is non-zero it's a physical register...
- if (allocSelection != 0) {
- // Get the physical reg, subtracting 1 to account for the spill option.
- unsigned physReg = allowedSets[node][allocSelection - 1];
-
- DEBUG(dbgs() << "VREG " << virtReg << " -> "
- << tri->getName(physReg) << " (Option: " << allocSelection << ")\n");
-
- assert(physReg != 0);
-
- // Add to the virt reg map and update the used phys regs.
- vrm->assignVirt2Phys(virtReg, physReg);
- }
- // ...Otherwise it's a spill.
- else {
-
- // Make sure we ignore this virtual reg on the next round
- // of allocation
- vregsToAlloc.erase(virtReg);
-
- // Insert spill ranges for this live range
- const LiveInterval *spillInterval = node2LI[node];
- double oldSpillWeight = spillInterval->weight;
- SmallVector<LiveInterval*, 8> spillIs;
- rmf->rememberUseDefs(spillInterval);
- std::vector<LiveInterval*> newSpills =
- lis->addIntervalsForSpills(*spillInterval, spillIs, loopInfo, *vrm);
- addStackInterval(spillInterval, mri);
- rmf->rememberSpills(spillInterval, newSpills);
-
- (void) oldSpillWeight;
- DEBUG(dbgs() << "VREG " << virtReg << " -> SPILLED (Option: 0, Cost: "
- << oldSpillWeight << ", New vregs: ");
-
- // Copy any newly inserted live intervals into the list of regs to
- // allocate.
- for (std::vector<LiveInterval*>::const_iterator
- itr = newSpills.begin(), end = newSpills.end();
- itr != end; ++itr) {
-
- assert(!(*itr)->empty() && "Empty spill range.");
-
- DEBUG(dbgs() << (*itr)->reg << " ");
-
- vregsToAlloc.insert((*itr)->reg);
- }
-
- DEBUG(dbgs() << ")\n");
-
- // We need another round if spill intervals were added.
- anotherRoundNeeded |= !newSpills.empty();
- }
- }
-
- return !anotherRoundNeeded;
-}
-
-bool RegAllocPBQP::mapPBQPToRegAlloc2(const PBQPRAProblem &problem,
- const PBQP::Solution &solution) {
+bool RegAllocPBQP::mapPBQPToRegAlloc(const PBQPRAProblem &problem,
+ const PBQP::Solution &solution) {
// Set to true if we have any spills
bool anotherRoundNeeded = false;
vregsToAlloc.erase(vreg);
const LiveInterval* spillInterval = &lis->getInterval(vreg);
double oldWeight = spillInterval->weight;
- SmallVector<LiveInterval*, 8> spillIs;
rmf->rememberUseDefs(spillInterval);
std::vector<LiveInterval*> newSpills =
- lis->addIntervalsForSpills(*spillInterval, spillIs, loopInfo, *vrm);
+ lis->addIntervalsForSpills(*spillInterval, 0, loopInfo, *vrm);
addStackInterval(spillInterval, mri);
rmf->rememberSpills(spillInterval, newSpills);
if (physReg == 0) {
const TargetRegisterClass *liRC = mri->getRegClass(li->reg);
- physReg = *liRC->allocation_order_begin(*mf);
+ physReg = liRC->getRawAllocationOrder(*mf).front();
}
vrm->assignVirt2Phys(li->reg, physReg);
// Get the physical register for this interval
if (TargetRegisterInfo::isPhysicalRegister(li->reg)) {
reg = li->reg;
- }
- else if (vrm->isAssignedReg(li->reg)) {
+ } else if (vrm->isAssignedReg(li->reg)) {
reg = vrm->getPhys(li->reg);
- }
- else {
+ } else {
// Ranges which are assigned a stack slot only are ignored.
continue;
}
// Find the set of basic blocks which this range is live into...
if (lis->findLiveInMBBs(lrItr->start, lrItr->end, liveInMBBs)) {
// And add the physreg for this interval to their live-in sets.
- for (unsigned i = 0; i < liveInMBBs.size(); ++i) {
+ for (unsigned i = 0; i != liveInMBBs.size(); ++i) {
if (liveInMBBs[i] != entryMBB) {
if (!liveInMBBs[i]->isLiveIn(reg)) {
liveInMBBs[i]->addLiveIn(reg);
bool pbqpAllocComplete = false;
unsigned round = 0;
- if (!pbqpBuilder) {
- while (!pbqpAllocComplete) {
- DEBUG(dbgs() << " PBQP Regalloc round " << round << ":\n");
-
- PBQP::Graph problem = constructPBQPProblem();
- PBQP::Solution solution =
- PBQP::HeuristicSolver<PBQP::Heuristics::Briggs>::solve(problem);
-
- pbqpAllocComplete = mapPBQPToRegAlloc(solution);
-
- ++round;
- }
- } else {
- while (!pbqpAllocComplete) {
- DEBUG(dbgs() << " PBQP Regalloc round " << round << ":\n");
+ while (!pbqpAllocComplete) {
+ DEBUG(dbgs() << " PBQP Regalloc round " << round << ":\n");
- std::auto_ptr<PBQPRAProblem> problem =
- builder->build(mf, lis, vregsToAlloc);
- PBQP::Solution solution =
- HeuristicSolver<Briggs>::solve(problem->getGraph());
+ std::auto_ptr<PBQPRAProblem> problem =
+ builder->build(mf, lis, loopInfo, vregsToAlloc);
+ PBQP::Solution solution =
+ PBQP::HeuristicSolver<PBQP::Heuristics::Briggs>::solve(
+ problem->getGraph());
- pbqpAllocComplete = mapPBQPToRegAlloc2(*problem, solution);
+ pbqpAllocComplete = mapPBQPToRegAlloc(*problem, solution);
- ++round;
- }
+ ++round;
}
}
vregsToAlloc.clear();
emptyIntervalVRegs.clear();
- li2Node.clear();
- node2LI.clear();
- allowedSets.clear();
- problemNodes.clear();
DEBUG(dbgs() << "Post alloc VirtRegMap:\n" << *vrm << "\n");
return true;
}
-FunctionPass* createPBQPRegisterAllocator() {
- return new RegAllocPBQP(std::auto_ptr<PBQPBuilder>(new PBQPBuilder()));
+FunctionPass* llvm::createPBQPRegisterAllocator(
+ std::auto_ptr<PBQPBuilder> builder,
+ char *customPassID) {
+ return new RegAllocPBQP(builder, customPassID);
}
+FunctionPass* llvm::createDefaultPBQPRegisterAllocator() {
+ if (pbqpCoalescing) {
+ return createPBQPRegisterAllocator(
+ std::auto_ptr<PBQPBuilder>(new PBQPBuilderWithCoalescing()));
+ } // else
+ return createPBQPRegisterAllocator(
+ std::auto_ptr<PBQPBuilder>(new PBQPBuilder()));
}
#undef DEBUG_TYPE
projects / oota-llvm.git / blobdiff