blob: dfaf7f5846527c4c852d308e5a84543329cd3fc9 [file] [log] [blame]
//===-------- EdgeBundles.cpp - Bundles of CFG edges ----------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// 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/InitializePasses.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/GraphWriter.h"
#include "llvm/Support/raw_ostream.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, /* is_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 (const auto &MBB : *MF) {
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, false);
unsigned b1 = getBundle(i, true);
Blocks[b0].push_back(i);
if (b1 != b0)
Blocks[b1].push_back(i);
}
return false;
}
/// Specialize WriteGraph, the standard implementation won't work.
namespace llvm {
template<>
raw_ostream &WriteGraph<>(raw_ostream &O, const EdgeBundles &G,
bool ShortNames,
const Twine &Title) {
const MachineFunction *MF = G.getMachineFunction();
O << "digraph {\n";
for (const auto &MBB : *MF) {
unsigned BB = MBB.getNumber();
O << "\t\"" << printMBBReference(MBB) << "\" [ shape=box ]\n"
<< '\t' << G.getBundle(BB, false) << " -> \"" << printMBBReference(MBB)
<< "\"\n"
<< "\t\"" << printMBBReference(MBB) << "\" -> " << G.getBundle(BB, true)
<< '\n';
for (MachineBasicBlock::const_succ_iterator SI = MBB.succ_begin(),
SE = MBB.succ_end(); SI != SE; ++SI)
O << "\t\"" << printMBBReference(MBB) << "\" -> \""
<< printMBBReference(**SI) << "\" [ color=lightgray ]\n";
}
O << "}\n";
return O;
}
} // end namespace llvm
/// view - Visualize the annotated bipartite CFG with Graphviz.
void EdgeBundles::view() const {
ViewGraph(*this, "EdgeBundles");
}