llvm-6502/include/llvm/CodeGen/LatencyPriorityQueue.h
Dan Gohman 93d3433579 Eliminate the use of PriorityQueue and just use a std::vector,
implementing pop with a linear search for a "best" element. The priority
queue was a neat idea, but in practice the comparison functions depend
on dynamic information.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104718 91177308-0d34-0410-b5e6-96231b3b80d8
2010-05-26 18:52:00 +00:00

97 lines
2.9 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"
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;
/// 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;
/// Queue - The queue.
std::vector<SUnit*> Queue;
latency_sort Picker;
public:
LatencyPriorityQueue() : Picker(this) {
}
void initNodes(std::vector<SUnit> &sunits) {
SUnits = &sunits;
NumNodesSolelyBlocking.resize(SUnits->size(), 0);
}
void addNode(const SUnit *SU) {
NumNodesSolelyBlocking.resize(SUnits->size(), 0);
}
void updateNode(const SUnit *SU) {
}
void releaseState() {
SUnits = 0;
}
unsigned getLatency(unsigned NodeNum) const {
assert(NodeNum < (*SUnits).size());
return (*SUnits)[NodeNum].getHeight();
}
unsigned getNumSolelyBlockNodes(unsigned NodeNum) const {
assert(NodeNum < NumNodesSolelyBlocking.size());
return NumNodesSolelyBlocking[NodeNum];
}
bool empty() const { return Queue.empty(); }
virtual void push(SUnit *U);
virtual SUnit *pop();
virtual void remove(SUnit *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 AdjustPriorityOfUnscheduledPreds(SUnit *SU);
SUnit *getSingleUnscheduledPred(SUnit *SU);
};
}
#endif