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Diffstat (limited to 'contrib/llvm/tools/opt/PrintSCC.cpp')
-rw-r--r-- | contrib/llvm/tools/opt/PrintSCC.cpp | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/contrib/llvm/tools/opt/PrintSCC.cpp b/contrib/llvm/tools/opt/PrintSCC.cpp new file mode 100644 index 0000000..11efdcd --- /dev/null +++ b/contrib/llvm/tools/opt/PrintSCC.cpp @@ -0,0 +1,112 @@ +//===- PrintSCC.cpp - Enumerate SCCs in some key graphs -------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// 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/Pass.h" +#include "llvm/Module.h" +#include "llvm/Analysis/CallGraph.h" +#include "llvm/Support/CFG.h" +#include "llvm/Support/raw_ostream.h" +#include "llvm/ADT/SCCIterator.h" +using namespace llvm; + +namespace { + struct CFGSCC : public FunctionPass { + static char ID; // Pass identification, replacement for typeid + CFGSCC() : FunctionPass(ID) {} + bool runOnFunction(Function& func); + + void print(raw_ostream &O, const Module* = 0) const { } + + virtual void getAnalysisUsage(AnalysisUsage &AU) const { + AU.setPreservesAll(); + } + }; + + struct CallGraphSCC : public ModulePass { + static char ID; // Pass identification, replacement for typeid + CallGraphSCC() : ModulePass(ID) {} + + // run - Print out SCCs in the call graph for the specified module. + bool runOnModule(Module &M); + + void print(raw_ostream &O, const Module* = 0) const { } + + // getAnalysisUsage - This pass requires the CallGraph. + virtual void getAnalysisUsage(AnalysisUsage &AU) const { + AU.setPreservesAll(); + AU.addRequired<CallGraph>(); + } + }; +} + +char CFGSCC::ID = 0; +static RegisterPass<CFGSCC> +Y("print-cfg-sccs", "Print SCCs of each function CFG"); + +char CallGraphSCC::ID = 0; +static RegisterPass<CallGraphSCC> +Z("print-callgraph-sccs", "Print SCCs of the Call Graph"); + +bool CFGSCC::runOnFunction(Function &F) { + unsigned sccNum = 0; + errs() << "SCCs for Function " << F.getName() << " in PostOrder:"; + for (scc_iterator<Function*> SCCI = scc_begin(&F), + E = scc_end(&F); SCCI != E; ++SCCI) { + std::vector<BasicBlock*> &nextSCC = *SCCI; + errs() << "\nSCC #" << ++sccNum << " : "; + for (std::vector<BasicBlock*>::const_iterator I = nextSCC.begin(), + E = nextSCC.end(); I != E; ++I) + errs() << (*I)->getName() << ", "; + if (nextSCC.size() == 1 && SCCI.hasLoop()) + errs() << " (Has self-loop)."; + } + errs() << "\n"; + + return true; +} + + +// run - Print out SCCs in the call graph for the specified module. +bool CallGraphSCC::runOnModule(Module &M) { + CallGraphNode* rootNode = getAnalysis<CallGraph>().getRoot(); + unsigned sccNum = 0; + errs() << "SCCs for the program in PostOrder:"; + for (scc_iterator<CallGraphNode*> SCCI = scc_begin(rootNode), + E = scc_end(rootNode); SCCI != E; ++SCCI) { + const std::vector<CallGraphNode*> &nextSCC = *SCCI; + errs() << "\nSCC #" << ++sccNum << " : "; + for (std::vector<CallGraphNode*>::const_iterator I = nextSCC.begin(), + E = nextSCC.end(); I != E; ++I) + errs() << ((*I)->getFunction() ? (*I)->getFunction()->getName() + : "external node") << ", "; + if (nextSCC.size() == 1 && SCCI.hasLoop()) + errs() << " (Has self-loop)."; + } + errs() << "\n"; + + return true; +} |