llvm-6502/lib/CodeGen/SelectionDAG/LatencyPriorityQueue.h
Dan Gohman 3dbc4e3502 Whitespace cleanups.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59532 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-18 17:05:42 +00:00

125 lines
3.7 KiB
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//===---- LatencyPriorityQueue.h - A latency-oriented priority queue ------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file declares the LatencyPriorityQueue class, which is a
// SchedulingPriorityQueue that schedules using latency information to
// reduce the length of the critical path through the basic block.
//
//===----------------------------------------------------------------------===//
#ifndef LATENCY_PRIORITY_QUEUE_H
#define LATENCY_PRIORITY_QUEUE_H
#include "llvm/CodeGen/ScheduleDAG.h"
#include "llvm/ADT/PriorityQueue.h"
namespace llvm {
class LatencyPriorityQueue;
/// Sorting functions for the Available queue.
struct latency_sort : public std::binary_function<SUnit*, SUnit*, bool> {
LatencyPriorityQueue *PQ;
explicit latency_sort(LatencyPriorityQueue *pq) : PQ(pq) {}
bool operator()(const SUnit* left, const SUnit* right) const;
};
class LatencyPriorityQueue : public SchedulingPriorityQueue {
// SUnits - The SUnits for the current graph.
std::vector<SUnit> *SUnits;
// Latencies - The latency (max of latency from this node to the bb exit)
// for each node.
std::vector<int> Latencies;
/// NumNodesSolelyBlocking - This vector contains, for every node in the
/// Queue, the number of nodes that the node is the sole unscheduled
/// predecessor for. This is used as a tie-breaker heuristic for better
/// mobility.
std::vector<unsigned> NumNodesSolelyBlocking;
PriorityQueue<SUnit*, std::vector<SUnit*>, latency_sort> Queue;
public:
LatencyPriorityQueue() : Queue(latency_sort(this)) {
}
void initNodes(std::vector<SUnit> &sunits) {
SUnits = &sunits;
// Calculate node priorities.
CalculatePriorities();
}
void addNode(const SUnit *SU) {
Latencies.resize(SUnits->size(), -1);
NumNodesSolelyBlocking.resize(SUnits->size(), 0);
CalcLatency(*SU);
}
void updateNode(const SUnit *SU) {
Latencies[SU->NodeNum] = -1;
CalcLatency(*SU);
}
void releaseState() {
SUnits = 0;
Latencies.clear();
}
unsigned getLatency(unsigned NodeNum) const {
assert(NodeNum < Latencies.size());
return Latencies[NodeNum];
}
unsigned getNumSolelyBlockNodes(unsigned NodeNum) const {
assert(NodeNum < NumNodesSolelyBlocking.size());
return NumNodesSolelyBlocking[NodeNum];
}
unsigned size() const { return Queue.size(); }
bool empty() const { return Queue.empty(); }
virtual void push(SUnit *U) {
push_impl(U);
}
void push_impl(SUnit *U);
void push_all(const std::vector<SUnit *> &Nodes) {
for (unsigned i = 0, e = Nodes.size(); i != e; ++i)
push_impl(Nodes[i]);
}
SUnit *pop() {
if (empty()) return NULL;
SUnit *V = Queue.top();
Queue.pop();
return V;
}
void remove(SUnit *SU) {
assert(!Queue.empty() && "Not in queue!");
Queue.erase_one(SU);
}
// ScheduledNode - As nodes are scheduled, we look to see if there are any
// successor nodes that have a single unscheduled predecessor. If so, that
// single predecessor has a higher priority, since scheduling it will make
// the node available.
void ScheduledNode(SUnit *Node);
private:
void CalculatePriorities();
int CalcLatency(const SUnit &SU);
void AdjustPriorityOfUnscheduledPreds(SUnit *SU);
SUnit *getSingleUnscheduledPred(SUnit *SU);
};
}
#endif