llvm-6502/lib/Analysis/Interval.cpp

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//===- Interval.cpp - Interval class code ------------------------*- C++ -*--=//
//
// This file contains the definition of the cfg::Interval class, which
// represents a partition of a control flow graph of some kind.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/Interval.h"
#include "llvm/BasicBlock.h"
//===----------------------------------------------------------------------===//
// Interval Implementation
//===----------------------------------------------------------------------===//
// isLoop - Find out if there is a back edge in this interval...
//
bool cfg::Interval::isLoop() const {
// There is a loop in this interval iff one of the predecessors of the header
// node lives in the interval.
for (BasicBlock::pred_iterator I = HeaderNode->pred_begin(),
E = HeaderNode->pred_end(); I != E; ++I) {
if (contains(*I)) return true;
}
return false;
}