llvm-project/llvm/lib/CodeGen/EdgeBundles.cpp
Kai Luo d2b8969b75
[EdgeBundles] Correct MBB label name in output graph when -view-edge-bundles. NFC. (#106661)
With `-view-edge-bundles`, before the change, the dot file output is
kinda like
```dot
digraph {
        "%bb.0" [ shape=box ]
        0 -> "%bb.0"
        "%bb.0" -> 1
        "%bb.0" -> "%bb.1" [ color=lightgray ]
        "%bb.0" -> "%bb.6" [ color=lightgray ]
        "%bb.1" [ shape=box ]
        1 -> "%bb.1"
        "%bb.1" -> 1
        "%bb.1" -> "%bb.2" [ color=lightgray ]
        "%bb.1" -> "%bb.6" [ color=lightgray ]
        "%bb.2" [ shape=box ]
        1 -> "%bb.2"
        "%bb.2" -> 1
        "%bb.2" -> "%bb.3" [ color=lightgray ]
        "%bb.3" [ shape=box ]
        1 -> "%bb.3"
        "%bb.3" -> 2
        "%bb.3" -> "%bb.4" [ color=lightgray ]
        "%bb.4" [ shape=box ]
        2 -> "%bb.4"
        "%bb.4" -> 2
        "%bb.4" -> "%bb.4" [ color=lightgray ]
        "%bb.4" -> "%bb.5" [ color=lightgray ]
        "%bb.5" [ shape=box ]
        2 -> "%bb.5"
        "%bb.5" -> 1
        "%bb.5" -> "%bb.6" [ color=lightgray ]
        "%bb.5" -> "%bb.3" [ color=lightgray ]
        "%bb.6" [ shape=box ]
        1 -> "%bb.6"
        "%bb.6" -> 3
}
```
However, the graph output by graphviz is

![t](https://github.com/user-attachments/assets/24056c0a-3ba9-49c3-a5da-269f3140e619)
The node name corresponding to the MBB is incorrect.
After the change, the node name is consistent with MBB's name.

![s](https://github.com/user-attachments/assets/38c649d1-7222-4de1-971c-56f7721ab64c)
2024-08-30 15:56:27 +08:00

103 lines
3.1 KiB
C++

//===-------- 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/ADT/Twine.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 (const MachineBasicBlock *Succ : MBB.successors())
EC.join(OutE, 2 * Succ->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;
}
namespace llvm {
/// Specialize WriteGraph, the standard implementation won't work.
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, label=\""
<< printMBBReference(MBB) << "\" ]\n"
<< '\t' << G.getBundle(BB, false) << " -> \"" << printMBBReference(MBB)
<< "\"\n"
<< "\t\"" << printMBBReference(MBB) << "\" -> " << G.getBundle(BB, true)
<< '\n';
for (const MachineBasicBlock *Succ : MBB.successors())
O << "\t\"" << printMBBReference(MBB) << "\" -> \""
<< printMBBReference(*Succ) << "\" [ 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");
}