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-rw-r--r--llvm/lib/CodeGen/RegAllocPBQP.cpp284
1 files changed, 178 insertions, 106 deletions
diff --git a/llvm/lib/CodeGen/RegAllocPBQP.cpp b/llvm/lib/CodeGen/RegAllocPBQP.cpp
index 862ce00e1c8..63c7d3d2ddd 100644
--- a/llvm/lib/CodeGen/RegAllocPBQP.cpp
+++ b/llvm/lib/CodeGen/RegAllocPBQP.cpp
@@ -31,7 +31,9 @@
#define DEBUG_TYPE "regalloc"
-#include "PBQP.h"
+#include "PBQP/HeuristicSolver.h"
+#include "PBQP/SimpleGraph.h"
+#include "PBQP/Heuristics/Briggs.h"
#include "VirtRegMap.h"
#include "VirtRegRewriter.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
@@ -54,42 +56,41 @@
using namespace llvm;
static RegisterRegAlloc
-registerPBQPRepAlloc("pbqp", "PBQP register allocator",
- createPBQPRegisterAllocator);
+registerPBQPRepAlloc("pbqp", "PBQP register allocator.",
+ llvm::createPBQPRegisterAllocator);
namespace {
- //!
- //! PBQP based allocators solve the register allocation problem by mapping
- //! register allocation problems to Partitioned Boolean Quadratic
- //! Programming problems.
+ ///
+ /// PBQP based allocators solve the register allocation problem by mapping
+ /// register allocation problems to Partitioned Boolean Quadratic
+ /// Programming problems.
class VISIBILITY_HIDDEN PBQPRegAlloc : public MachineFunctionPass {
public:
static char ID;
-
- //! Construct a PBQP register allocator.
+
+ /// Construct a PBQP register allocator.
PBQPRegAlloc() : MachineFunctionPass((intptr_t)&ID) {}
- //! Return the pass name.
+ /// Return the pass name.
virtual const char* getPassName() const throw() {
return "PBQP Register Allocator";
}
- //! PBQP analysis usage.
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.setPreservesCFG();
- AU.addRequired<LiveIntervals>();
- AU.addRequiredTransitive<RegisterCoalescer>();
- AU.addRequired<LiveStacks>();
- AU.addPreserved<LiveStacks>();
- AU.addRequired<MachineLoopInfo>();
- AU.addPreserved<MachineLoopInfo>();
- AU.addRequired<VirtRegMap>();
- MachineFunctionPass::getAnalysisUsage(AU);
+ /// PBQP analysis usage.
+ virtual void getAnalysisUsage(AnalysisUsage &au) const {
+ au.addRequired<LiveIntervals>();
+ //au.addRequiredID(SplitCriticalEdgesID);
+ au.addRequired<LiveStacks>();
+ au.addPreserved<LiveStacks>();
+ au.addRequired<MachineLoopInfo>();
+ au.addPreserved<MachineLoopInfo>();
+ au.addRequired<VirtRegMap>();
+ MachineFunctionPass::getAnalysisUsage(au);
}
- //! Perform register allocation
+ /// Perform register allocation
virtual bool runOnMachineFunction(MachineFunction &MF);
private:
@@ -99,7 +100,7 @@ namespace {
typedef std::vector<AllowedSet> AllowedSetMap;
typedef std::set<unsigned> RegSet;
typedef std::pair<unsigned, unsigned> RegPair;
- typedef std::map<RegPair, PBQPNum> CoalesceMap;
+ typedef std::map<RegPair, PBQP::PBQPNum> CoalesceMap;
typedef std::set<LiveInterval*> LiveIntervalSet;
@@ -121,60 +122,60 @@ namespace {
emptyVRegIntervals;
- //! Builds a PBQP cost vector.
+ /// Builds a PBQP cost vector.
template <typename RegContainer>
- PBQPVector* buildCostVector(unsigned vReg,
- const RegContainer &allowed,
- const CoalesceMap &cealesces,
- PBQPNum spillCost) const;
-
- //! \brief Builds a PBQP interference matrix.
- //!
- //! @return Either a pointer to a non-zero PBQP matrix representing the
- //! allocation option costs, or a null pointer for a zero matrix.
- //!
- //! Expects allowed sets for two interfering LiveIntervals. These allowed
- //! sets should contain only allocable registers from the LiveInterval's
- //! register class, with any interfering pre-colored registers removed.
+ PBQP::Vector buildCostVector(unsigned vReg,
+ const RegContainer &allowed,
+ const CoalesceMap &cealesces,
+ PBQP::PBQPNum spillCost) const;
+
+ /// \brief Builds a PBQP interference matrix.
+ ///
+ /// @return Either a pointer to a non-zero PBQP matrix representing the
+ /// allocation option costs, or a null pointer for a zero matrix.
+ ///
+ /// Expects allowed sets for two interfering LiveIntervals. These allowed
+ /// sets should contain only allocable registers from the LiveInterval's
+ /// register class, with any interfering pre-colored registers removed.
template <typename RegContainer>
- PBQPMatrix* buildInterferenceMatrix(const RegContainer &allowed1,
- const RegContainer &allowed2) const;
-
- //!
- //! Expects allowed sets for two potentially coalescable LiveIntervals,
- //! and an estimated benefit due to coalescing. The allowed sets should
- //! contain only allocable registers from the LiveInterval's register
- //! classes, with any interfering pre-colored registers removed.
+ PBQP::Matrix* buildInterferenceMatrix(const RegContainer &allowed1,
+ const RegContainer &allowed2) const;
+
+ ///
+ /// Expects allowed sets for two potentially coalescable LiveIntervals,
+ /// and an estimated benefit due to coalescing. The allowed sets should
+ /// contain only allocable registers from the LiveInterval's register
+ /// classes, with any interfering pre-colored registers removed.
template <typename RegContainer>
- PBQPMatrix* buildCoalescingMatrix(const RegContainer &allowed1,
- const RegContainer &allowed2,
- PBQPNum cBenefit) const;
-
- //! \brief Finds coalescing opportunities and returns them as a map.
- //!
- //! Any entries in the map are guaranteed coalescable, even if their
- //! corresponding live intervals overlap.
+ PBQP::Matrix* buildCoalescingMatrix(const RegContainer &allowed1,
+ const RegContainer &allowed2,
+ PBQP::PBQPNum cBenefit) const;
+
+ /// \brief Finds coalescing opportunities and returns them as a map.
+ ///
+ /// Any entries in the map are guaranteed coalescable, even if their
+ /// corresponding live intervals overlap.
CoalesceMap findCoalesces();
- //! \brief Finds the initial set of vreg intervals to allocate.
+ /// \brief Finds the initial set of vreg intervals to allocate.
void findVRegIntervalsToAlloc();
- //! \brief Constructs a PBQP problem representation of the register
- //! allocation problem for this function.
- //!
- //! @return a PBQP solver object for the register allocation problem.
- pbqp* constructPBQPProblem();
+ /// \brief Constructs a PBQP problem representation of the register
+ /// allocation problem for this function.
+ ///
+ /// @return a PBQP solver object for the register allocation problem.
+ PBQP::SimpleGraph constructPBQPProblem();
- //! \brief Adds a stack interval if the given live interval has been
- //! spilled. Used to support stack slot coloring.
+ /// \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(pbqp *problem);
+ /// \brief Given a solved PBQP problem maps this solution back to a register
+ /// assignment.
+ bool mapPBQPToRegAlloc(const PBQP::Solution &solution);
- //! \brief Postprocessing before final spilling. Sets basic block "live in"
- //! variables.
+ /// \brief Postprocessing before final spilling. Sets basic block "live in"
+ /// variables.
void finalizeAlloc() const;
};
@@ -184,17 +185,17 @@ namespace {
template <typename RegContainer>
-PBQPVector* PBQPRegAlloc::buildCostVector(unsigned vReg,
- const RegContainer &allowed,
- const CoalesceMap &coalesces,
- PBQPNum spillCost) const {
+PBQP::Vector PBQPRegAlloc::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
- PBQPVector *v = new PBQPVector(allowed.size() + 1);
+ PBQP::Vector v(allowed.size() + 1, 0);
- (*v)[0] = spillCost;
+ v[0] = spillCost;
// Iterate over the allowed registers inserting coalesce benefits if there
// are any.
@@ -212,14 +213,14 @@ PBQPVector* PBQPRegAlloc::buildCostVector(unsigned vReg,
continue;
// We have a coalesce - insert the benefit.
- (*v)[ai + 1] = -cmItr->second;
+ v[ai + 1] = -cmItr->second;
}
return v;
}
template <typename RegContainer>
-PBQPMatrix* PBQPRegAlloc::buildInterferenceMatrix(
+PBQP::Matrix* PBQPRegAlloc::buildInterferenceMatrix(
const RegContainer &allowed1, const RegContainer &allowed2) const {
typedef typename RegContainer::const_iterator RegContainerIterator;
@@ -232,7 +233,8 @@ PBQPMatrix* PBQPRegAlloc::buildInterferenceMatrix(
// 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).
- PBQPMatrix *m = new PBQPMatrix(allowed1.size() + 1, allowed2.size() + 1);
+ 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.
@@ -262,7 +264,7 @@ PBQPMatrix* PBQPRegAlloc::buildInterferenceMatrix(
// If the row/column regs are identical or alias insert an infinity.
if ((reg1 == reg2) || tri->areAliases(reg1, reg2)) {
- (*m)[ri][ci] = std::numeric_limits<PBQPNum>::infinity();
+ (*m)[ri][ci] = std::numeric_limits<PBQP::PBQPNum>::infinity();
isZeroMatrix = false;
}
@@ -284,9 +286,9 @@ PBQPMatrix* PBQPRegAlloc::buildInterferenceMatrix(
}
template <typename RegContainer>
-PBQPMatrix* PBQPRegAlloc::buildCoalescingMatrix(
+PBQP::Matrix* PBQPRegAlloc::buildCoalescingMatrix(
const RegContainer &allowed1, const RegContainer &allowed2,
- PBQPNum cBenefit) const {
+ PBQP::PBQPNum cBenefit) const {
typedef typename RegContainer::const_iterator RegContainerIterator;
@@ -295,7 +297,8 @@ PBQPMatrix* PBQPRegAlloc::buildCoalescingMatrix(
// 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.
- PBQPMatrix *m = new PBQPMatrix(allowed1.size() + 1, allowed2.size() + 1);
+ PBQP::Matrix *m =
+ new PBQP::Matrix(allowed1.size() + 1, allowed2.size() + 1, 0);
// Reset costs to zero.
m->reset(0);
@@ -497,10 +500,11 @@ void PBQPRegAlloc::findVRegIntervalsToAlloc() {
}
}
-pbqp* PBQPRegAlloc::constructPBQPProblem() {
+PBQP::SimpleGraph PBQPRegAlloc::constructPBQPProblem() {
typedef std::vector<const LiveInterval*> LIVector;
typedef std::vector<unsigned> RegVector;
+ typedef std::vector<PBQP::SimpleGraph::NodeIterator> NodeVector;
// This will store the physical intervals for easy reference.
LIVector physIntervals;
@@ -532,10 +536,11 @@ pbqp* PBQPRegAlloc::constructPBQPProblem() {
}
// Get the set of potential coalesces.
- CoalesceMap coalesces(findCoalesces());
+ CoalesceMap coalesces;//(findCoalesces());
// Construct a PBQP solver for this problem
- pbqp *solver = alloc_pbqp(vregIntervalsToAlloc.size());
+ PBQP::SimpleGraph problem;
+ NodeVector problemNodes(vregIntervalsToAlloc.size());
// Resize allowedSets container appropriately.
allowedSets.resize(vregIntervalsToAlloc.size());
@@ -596,13 +601,13 @@ pbqp* PBQPRegAlloc::constructPBQPProblem() {
// Set the spill cost to the interval weight, or epsilon if the
// interval weight is zero
- PBQPNum spillCost = (li->weight != 0.0) ?
- li->weight : std::numeric_limits<PBQPNum>::min();
+ PBQP::PBQPNum spillCost = (li->weight != 0.0) ?
+ li->weight : std::numeric_limits<PBQP::PBQPNum>::min();
// Build a cost vector for this interval.
- add_pbqp_nodecosts(solver, node,
- buildCostVector(li->reg, allowedSets[node], coalesces,
- spillCost));
+ problemNodes[node] =
+ problem.addNode(
+ buildCostVector(li->reg, allowedSets[node], coalesces, spillCost));
}
@@ -618,7 +623,7 @@ pbqp* PBQPRegAlloc::constructPBQPProblem() {
CoalesceMap::const_iterator cmItr =
coalesces.find(RegPair(li->reg, li2->reg));
- PBQPMatrix *m = 0;
+ PBQP::Matrix *m = 0;
if (cmItr != coalesces.end()) {
m = buildCoalescingMatrix(allowedSets[node1], allowedSets[node2],
@@ -629,14 +634,29 @@ pbqp* PBQPRegAlloc::constructPBQPProblem() {
}
if (m != 0) {
- add_pbqp_edgecosts(solver, node1, node2, m);
+ problem.addEdge(problemNodes[node1],
+ problemNodes[node2],
+ *m);
+
delete m;
}
}
}
+ problem.assignNodeIDs();
+
+ assert(problem.getNumNodes() == allowedSets.size());
+ for (unsigned i = 0; i < allowedSets.size(); ++i) {
+ assert(problem.getNodeItr(i) == problemNodes[i]);
+ }
+/*
+ std::cerr << "Allocating for " << problem.getNumNodes() << " nodes, "
+ << problem.getNumEdges() << " edges.\n";
+
+ problem.printDot(std::cerr);
+*/
// We're done, PBQP problem constructed - return it.
- return solver;
+ return problem;
}
void PBQPRegAlloc::addStackInterval(const LiveInterval *spilled,
@@ -659,7 +679,9 @@ void PBQPRegAlloc::addStackInterval(const LiveInterval *spilled,
stackInterval.MergeRangesInAsValue(rhsInterval, vni);
}
-bool PBQPRegAlloc::mapPBQPToRegAlloc(pbqp *problem) {
+bool PBQPRegAlloc::mapPBQPToRegAlloc(const PBQP::Solution &solution) {
+
+ static unsigned round = 0;
// Set to true if we have any spills
bool anotherRoundNeeded = false;
@@ -667,10 +689,56 @@ bool PBQPRegAlloc::mapPBQPToRegAlloc(pbqp *problem) {
// Clear the existing allocation.
vrm->clearAllVirt();
+ CoalesceMap coalesces;//(findCoalesces());
+
+ for (unsigned i = 0; i < node2LI.size(); ++i) {
+ if (solution.getSelection(i) == 0) {
+ continue;
+ }
+
+ unsigned iSel = solution.getSelection(i);
+ unsigned iAlloc = allowedSets[i][iSel - 1];
+
+ for (unsigned j = i + 1; j < node2LI.size(); ++j) {
+
+ if (solution.getSelection(j) == 0) {
+ continue;
+ }
+
+ unsigned jSel = solution.getSelection(j);
+ unsigned jAlloc = allowedSets[j][jSel - 1];
+
+ if ((iAlloc != jAlloc) && !tri->areAliases(iAlloc, jAlloc)) {
+ continue;
+ }
+
+ if (node2LI[i]->overlaps(*node2LI[j])) {
+ if (coalesces.find(RegPair(node2LI[i]->reg, node2LI[j]->reg)) == coalesces.end()) {
+ DEBUG(errs() << "In round " << ++round << ":\n"
+ << "Bogusness in " << mf->getFunction()->getName() << "!\n"
+ << "Live interval " << i << " (reg" << node2LI[i]->reg << ") and\n"
+ << "Live interval " << j << " (reg" << node2LI[j]->reg << ")\n"
+ << " were allocated registers " << iAlloc << " (index " << iSel << ") and "
+ << jAlloc << "(index " << jSel
+ << ") respectively in a graph of " << solution.numNodes() << " nodes.\n"
+ << "li[i]->empty() = " << node2LI[i]->empty() << "\n"
+ << "li[j]->empty() = " << node2LI[j]->empty() << "\n"
+ << "li[i]->overlaps(li[j]) = " << node2LI[i]->overlaps(*node2LI[j]) << "\n"
+ << "coalesce = " << (coalesces.find(RegPair(node2LI[i]->reg, node2LI[j]->reg)) != coalesces.end()) << "\n");
+
+ DEBUG(errs() << "solution.getCost() = " << solution.getCost() << "\n");
+ exit(1);
+ }
+ }
+ }
+ }
+
+
// 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 = get_pbqp_solution(problem, node);
+ allocSelection = solution.getSelection(node);
+
// If the PBQP solution is non-zero it's a physical register...
if (allocSelection != 0) {
@@ -731,11 +799,12 @@ void PBQPRegAlloc::finalizeAlloc() const {
// First allocate registers for the empty intervals.
for (LiveIntervalSet::const_iterator
- itr = emptyVRegIntervals.begin(), end = emptyVRegIntervals.end();
+ itr = emptyVRegIntervals.begin(), end = emptyVRegIntervals.end();
itr != end; ++itr) {
LiveInterval *li = *itr;
unsigned physReg = vrm->getRegAllocPref(li->reg);
+
if (physReg == 0) {
const TargetRegisterClass *liRC = mri->getRegClass(li->reg);
physReg = *liRC->allocation_order_begin(*mf);
@@ -766,8 +835,8 @@ void PBQPRegAlloc::finalizeAlloc() const {
continue;
}
- // Ignore unallocated vregs:
if (reg == 0) {
+ // Filter out zero regs - they're for intervals that were spilled.
continue;
}
@@ -806,8 +875,7 @@ bool PBQPRegAlloc::runOnMachineFunction(MachineFunction &MF) {
vrm = &getAnalysis<VirtRegMap>();
- DEBUG(errs() << "PBQP Register Allocating for "
- << mf->getFunction()->getName() << "\n");
+ DEBUG(errs() << "PBQP2 Register Allocating for " << mf->getFunction()->getName() << "\n");
// Allocator main loop:
//
@@ -832,15 +900,19 @@ bool PBQPRegAlloc::runOnMachineFunction(MachineFunction &MF) {
unsigned round = 0;
while (!pbqpAllocComplete) {
- DOUT << " PBQP Regalloc round " << round << ":\n";
-
- pbqp *problem = constructPBQPProblem();
-
- solve_pbqp(problem);
-
- pbqpAllocComplete = mapPBQPToRegAlloc(problem);
-
- free_pbqp(problem);
+ DEBUG(errs() << " PBQP Regalloc round " << round << ":\n");
+
+ PBQP::SimpleGraph problem = constructPBQPProblem();
+ PBQP::HeuristicSolver<PBQP::Heuristics::Briggs> solver;
+ problem.assignNodeIDs();
+ PBQP::Solution solution = solver.solve(problem);
+/*
+ std::cerr << "Solution:\n";
+ for (unsigned i = 0; i < solution.numNodes(); ++i) {
+ std::cerr << " " << i << " -> " << solution.getSelection(i) << "\n";
+ }
+*/
+ pbqpAllocComplete = mapPBQPToRegAlloc(solution);
++round;
}
@@ -855,7 +927,7 @@ bool PBQPRegAlloc::runOnMachineFunction(MachineFunction &MF) {
node2LI.clear();
allowedSets.clear();
- DOUT << "Post alloc VirtRegMap:\n" << *vrm << "\n";
+ DEBUG(errs() << "Post alloc VirtRegMap:\n" << *vrm << "\n");
// Run rewriter
std::auto_ptr<VirtRegRewriter> rewriter(createVirtRegRewriter());
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