ControlFlowGraphPass.cc

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/*
    Copyright (c) 2002-2009 Tampere University.
 
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/**
 * @file ControlFlowGraphPass.cc
 *
 * Definition of ControlFlowGraphPass class.
 *
 * @author Pekka Jääskeläinen 2007 (pjaaskel-no.spam-cs.tut.fi)
 * @note rating: red
 */
 
#include "ControlFlowGraphPass.hh"
#include "Application.hh"
#include "ControlFlowGraph.hh"
#include "Machine.hh"
#include "BasicBlockPass.hh"
 
/**
 * Constructor.
 */
ControlFlowGraphPass::ControlFlowGraphPass(InterPassData& data) : 
    SchedulerPass(data) {
}
 
/**
 * Destructor.
 */
ControlFlowGraphPass::~ControlFlowGraphPass() {
}
 
/**
 * Handles a single control flow graph.
 *
 * The pass should work with any kind of control flow graph, it should not
 * assume the CFG represents a whole procedure, for example.
 *
 * @param cfg The control flow graph to handle.
 * @param machine The target machine if any. (NullMachine::instance() if
 * target machine is irrelevant).
 * @exception In case handling is unsuccesful for any reason (cfg might 
 * still get modified).
 */
void
ControlFlowGraphPass::handleControlFlowGraph(
    ControlFlowGraph& cfg, const TTAMachine::Machine& targetMachine) {
    BasicBlockPass* bbPass = dynamic_cast<BasicBlockPass*>(this);
    if (bbPass != NULL) {
        executeBasicBlockPass(cfg, targetMachine, *bbPass);
    } else {
        abortWithError("CFG Pass is not also a BB pass so you "
                       "must overload handleControlFlowGraph method!");
    }
}
 
/**
 * Executes the given basic block pass on each basic block of the given
 * control flow graph in the original program order.
 *
 * A helper function for implementing most simplest types of CFG passes.
 *
 * @param cfg The control flow graph to handle.
 * @param targetMachine The target machine, if any. (NullMachine::instance() if
 * target machine is irrelevant).
 * @param bbPass The basic block pass to execute.
 * @exception In case handling is unsuccesful for any reason (cfg might 
 * still get modified).
 */
void
ControlFlowGraphPass::executeBasicBlockPass(
    ControlFlowGraph& cfg, const TTAMachine::Machine& targetMachine,
    BasicBlockPass& bbPass) {
    // first schedule all inner-loop basic blocks.
    int nodeCount = cfg.nodeCount();
    for (int bbIndex = 0; bbIndex < nodeCount; ++bbIndex) {
        BasicBlockNode& bb = dynamic_cast<BasicBlockNode&>(cfg.node(bbIndex));
        if (!bb.isNormalBB() || bb.isScheduled() || !cfg.isSingleBBLoop(bb)) {
            continue;
        }
        bbPass.handleBasicBlock(
            bb.basicBlock(), targetMachine,
            cfg.instructionReferenceManager(), &bb);
        bb.setScheduled();
        // if some node is removed, make sure does not skip some node and
        // then try to handle too many nodes.
        if (cfg.nodeCount() != nodeCount) {
            nodeCount = cfg.nodeCount();
            bbIndex = 0;
        }
    }
 
    // then other basic blocks.
    nodeCount = cfg.nodeCount();
    for (int bbIndex = 0; bbIndex < nodeCount; ++bbIndex) {
        BasicBlockNode& bb = dynamic_cast<BasicBlockNode&>(cfg.node(bbIndex));
        if (!bb.isNormalBB())
            continue;
        if (bb.isScheduled()) {
            continue;
        }
 
        bbPass.handleBasicBlock(
            bb.basicBlock(), targetMachine, 
            cfg.instructionReferenceManager(), &bb);
        bb.setScheduled();
        // if some node is removed, make sure does not skip some node and
        // then try to handle too many nodes.
        if (cfg.nodeCount() != nodeCount) {
            nodeCount = cfg.nodeCount();
            bbIndex = 0;
        }
    }
}