llvm-6502/lib/CodeGen/EdgeBundles.cpp

98 lines
3.1 KiB
C++

//===-------- EdgeBundles.cpp - Bundles of CFG edges ----------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file provides the implementation of the EdgeBundles analysis.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/EdgeBundles.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/GraphWriter.h"
using namespace llvm;
static cl::opt<bool>
ViewEdgeBundles("view-edge-bundles", cl::Hidden,
cl::desc("Pop up a window to show edge bundle graphs"));
char EdgeBundles::ID = 0;
INITIALIZE_PASS(EdgeBundles, "edge-bundles", "Bundle Machine CFG Edges",
/* cfg = */true, /* analysis = */ true)
char &llvm::EdgeBundlesID = EdgeBundles::ID;
void EdgeBundles::getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
MachineFunctionPass::getAnalysisUsage(AU);
}
bool EdgeBundles::runOnMachineFunction(MachineFunction &mf) {
MF = &mf;
EC.clear();
EC.grow(2 * MF->getNumBlockIDs());
for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); I != E;
++I) {
const MachineBasicBlock &MBB = *I;
unsigned OutE = 2 * MBB.getNumber() + 1;
// Join the outgoing bundle with the ingoing bundles of all successors.
for (MachineBasicBlock::const_succ_iterator SI = MBB.succ_begin(),
SE = MBB.succ_end(); SI != SE; ++SI)
EC.join(OutE, 2 * (*SI)->getNumber());
}
EC.compress();
if (ViewEdgeBundles)
view();
// Compute the reverse mapping.
Blocks.clear();
Blocks.resize(getNumBundles());
for (unsigned i = 0, e = MF->getNumBlockIDs(); i != e; ++i) {
unsigned b0 = getBundle(i, 0);
unsigned b1 = getBundle(i, 1);
Blocks[b0].push_back(i);
if (b1 != b0)
Blocks[b1].push_back(i);
}
return false;
}
/// view - Visualize the annotated bipartite CFG with Graphviz.
void EdgeBundles::view() const {
ViewGraph(*this, "EdgeBundles");
}
/// Specialize WriteGraph, the standard implementation won't work.
raw_ostream &llvm::WriteGraph(raw_ostream &O, const EdgeBundles &G,
bool ShortNames,
const std::string &Title) {
const MachineFunction *MF = G.getMachineFunction();
O << "digraph {\n";
for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
I != E; ++I) {
unsigned BB = I->getNumber();
O << "\t\"BB#" << BB << "\" [ shape=box ]\n"
<< '\t' << G.getBundle(BB, false) << " -> \"BB#" << BB << "\"\n"
<< "\t\"BB#" << BB << "\" -> " << G.getBundle(BB, true) << '\n';
for (MachineBasicBlock::const_succ_iterator SI = I->succ_begin(),
SE = I->succ_end(); SI != SE; ++SI)
O << "\t\"BB#" << BB << "\" -> \"BB#" << (*SI)->getNumber()
<< "\" [ color=lightgray ]\n";
}
O << "}\n";
return O;
}