60e4af7ab8
And remove the legacy opt-specific pass. Reviewed By: asbirlea Differential Revision: https://reviews.llvm.org/D135487
69 lines
2.4 KiB
C++
69 lines
2.4 KiB
C++
//===- PrintSCC.cpp - Enumerate SCCs in some key graphs -------------------===//
|
|
//
|
|
// 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 passes to print out SCCs in a CFG or a CallGraph.
|
|
// Normally, you would not use these passes; instead, you would use the
|
|
// scc_iterator directly to enumerate SCCs and process them in some way. These
|
|
// passes serve three purposes:
|
|
//
|
|
// (1) As a reference for how to use the scc_iterator.
|
|
// (2) To print out the SCCs for a CFG or a CallGraph:
|
|
// analyze -print-cfg-sccs to print the SCCs in each CFG of a module.
|
|
// analyze -print-cfg-sccs -stats to print the #SCCs and the maximum SCC size.
|
|
// analyze -print-cfg-sccs -debug > /dev/null to watch the algorithm in action.
|
|
//
|
|
// and similarly:
|
|
// analyze -print-callgraph-sccs [-stats] [-debug] to print SCCs in the CallGraph
|
|
//
|
|
// (3) To test the scc_iterator.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/ADT/SCCIterator.h"
|
|
#include "llvm/IR/CFG.h"
|
|
#include "llvm/IR/Module.h"
|
|
#include "llvm/Pass.h"
|
|
#include "llvm/Support/raw_ostream.h"
|
|
using namespace llvm;
|
|
|
|
namespace {
|
|
struct CFGSCC : public FunctionPass {
|
|
static char ID; // Pass identification, replacement for typeid
|
|
CFGSCC() : FunctionPass(ID) {}
|
|
bool runOnFunction(Function& func) override;
|
|
|
|
void print(raw_ostream &O, const Module* = nullptr) const override { }
|
|
|
|
void getAnalysisUsage(AnalysisUsage &AU) const override {
|
|
AU.setPreservesAll();
|
|
}
|
|
};
|
|
}
|
|
|
|
char CFGSCC::ID = 0;
|
|
static RegisterPass<CFGSCC>
|
|
Y("print-cfg-sccs", "Print SCCs of each function CFG");
|
|
|
|
bool CFGSCC::runOnFunction(Function &F) {
|
|
unsigned sccNum = 0;
|
|
errs() << "SCCs for Function " << F.getName() << " in PostOrder:";
|
|
for (scc_iterator<Function*> SCCI = scc_begin(&F); !SCCI.isAtEnd(); ++SCCI) {
|
|
const std::vector<BasicBlock *> &nextSCC = *SCCI;
|
|
errs() << "\nSCC #" << ++sccNum << " : ";
|
|
for (BasicBlock *BB : nextSCC) {
|
|
BB->printAsOperand(errs(), false);
|
|
errs() << ", ";
|
|
}
|
|
if (nextSCC.size() == 1 && SCCI.hasCycle())
|
|
errs() << " (Has self-loop).";
|
|
}
|
|
errs() << "\n";
|
|
|
|
return true;
|
|
}
|