llvm-6502/include/llvm/Analysis/Interval.h
Chris Lattner 4dd88f6fbf Big changes. Interval*.h is now more or less finalized. IntervalPartition
is recoded to use IntervalIterators.  IntervalIterators can now maintain
their own memory or let an external entity do it.

Loop depth is a new user of IntervalPartition for calculating the loop
nesting depth of a basic block

TODO: add IntervalPartition capability to split intervals between the looping
portion and the "tail" portion.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69 91177308-0d34-0410-b5e6-96231b3b80d8
2001-06-25 03:54:14 +00:00

116 lines
3.7 KiB
C++

//===- llvm/Analysis/Interval.h - Interval Class Declaration -----*- C++ -*--=//
//
// This file contains the declaration of the cfg::Interval class, which
// represents a set of CFG nodes and is a portion of an interval partition.
//
// Intervals have some interesting and useful properties, including the
// following:
// 1. The header node of an interval dominates all of the elements of the
// interval
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_INTERVAL_H
#define LLVM_INTERVAL_H
#include <vector>
class BasicBlock;
namespace cfg {
//===----------------------------------------------------------------------===//
//
// Interval Class - An Interval is a set of nodes defined such that every node
// in the interval has all of its predecessors in the interval (except for the
// header)
//
class Interval {
// HeaderNode - The header BasicBlock, which dominates all BasicBlocks in this
// interval. Also, any loops in this interval must go through the HeaderNode.
//
BasicBlock *HeaderNode;
public:
typedef vector<BasicBlock*>::iterator succ_iterator;
typedef vector<BasicBlock*>::iterator pred_iterator;
typedef vector<BasicBlock*>::iterator node_iterator;
inline Interval(BasicBlock *Header) : HeaderNode(Header) {
Nodes.push_back(Header);
}
inline Interval(const Interval &I) // copy ctor
: HeaderNode(I.HeaderNode), Nodes(I.Nodes), Successors(I.Successors) {}
inline BasicBlock *getHeaderNode() const { return HeaderNode; }
// Nodes - The basic blocks in this interval.
//
vector<BasicBlock*> Nodes;
// Successors - List of BasicBlocks that are reachable directly from nodes in
// this interval, but are not in the interval themselves.
// These nodes neccesarily must be header nodes for other intervals.
//
vector<BasicBlock*> Successors;
// Predecessors - List of BasicBlocks that have this Interval's header block
// as one of their successors.
//
vector<BasicBlock*> Predecessors;
// contains - Find out if a basic block is in this interval
inline bool contains(BasicBlock *BB) const {
for (unsigned i = 0; i < Nodes.size(); ++i)
if (Nodes[i] == BB) return true;
return false;
// I don't want the dependency on <algorithm>
//return find(Nodes.begin(), Nodes.end(), BB) != Nodes.end();
}
// isSuccessor - find out if a basic block is a successor of this Interval
inline bool isSuccessor(BasicBlock *BB) const {
for (unsigned i = 0; i < Successors.size(); ++i)
if (Successors[i] == BB) return true;
return false;
// I don't want the dependency on <algorithm>
//return find(Successors.begin(), Successors.end(), BB) != Successors.end();
}
// Equality operator. It is only valid to compare two intervals from the same
// partition, because of this, all we have to check is the header node for
// equality.
//
inline bool operator==(const Interval &I) const {
return HeaderNode == I.HeaderNode;
}
// isLoop - Find out if there is a back edge in this interval...
bool isLoop() const;
};
// succ_begin/succ_end - define global functions so that Intervals may be used
// just like BasicBlocks can with the succ_* functions, and *::succ_iterator.
//
inline Interval::succ_iterator succ_begin(Interval *I) {
return I->Successors.begin();
}
inline Interval::succ_iterator succ_end(Interval *I) {
return I->Successors.end();
}
// pred_begin/pred_end - define global functions so that Intervals may be used
// just like BasicBlocks can with the pred_* functions, and *::pred_iterator.
//
inline Interval::pred_iterator pred_begin(Interval *I) {
return I->Predecessors.begin();
}
inline Interval::pred_iterator pred_end(Interval *I) {
return I->Predecessors.end();
}
} // End namespace cfg
#endif