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| -rw-r--r-- | include/llvm/CallGraphSCCPass.h | 42 | ||||
| -rw-r--r-- | lib/Analysis/IPA/CallGraphSCCPass.cpp | 30 |
2 files changed, 72 insertions, 0 deletions
diff --git a/include/llvm/CallGraphSCCPass.h b/include/llvm/CallGraphSCCPass.h new file mode 100644 index 0000000000..1c22bad503 --- /dev/null +++ b/include/llvm/CallGraphSCCPass.h @@ -0,0 +1,42 @@ +//===- CallGraphSCCPass.h - Pass that operates BU on call graph -*- C++ -*-===// +// +// This file defines the CallGraphSCCPass class, which is used for passes which +// are implemented as bottom-up traversals on the call graph. Because there may +// be cycles in the call graph, passes of this type operate on the call-graph in +// SCC order: that is, they process function bottom-up, except for recursive +// functions, which they process all at once. +// +// These passes are inherently interprocedural, and are required to keep the +// call graph up-to-date if they do anything which could modify it. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_CALL_GRAPH_SCC_PASS_H +#define LLVM_CALL_GRAPH_SCC_PASS_H + +#include "llvm/Pass.h" + +class CallGraphNode; + +struct CallGraphSCCPass : public Pass { + + /// runOnSCC - This method should be implemented by the subclass to perform + /// whatever action is necessary for the specified SCC. Note that + /// non-recursive (or only self-recursive) functions will have an SCC size of + /// 1, where recursive portions of the call graph will have SCC size > 1. + /// + virtual bool runOnSCC(const std::vector<CallGraphNode *> &SCC) = 0; + + /// run - Run this pass, returning true if a modification was made to the + /// module argument. This is implemented in terms of the runOnSCC method. + /// + virtual bool run(Module &M); + + + /// getAnalysisUsage - For this class, we declare that we require and preserve + /// the call graph. If the derived class implements this method, it should + /// always explicitly call the implementation here. + virtual void getAnalysisUsage(AnalysisUsage &Info) const; +}; + +#endif diff --git a/lib/Analysis/IPA/CallGraphSCCPass.cpp b/lib/Analysis/IPA/CallGraphSCCPass.cpp new file mode 100644 index 0000000000..fd5e1ca80e --- /dev/null +++ b/lib/Analysis/IPA/CallGraphSCCPass.cpp @@ -0,0 +1,30 @@ +//===- CallGraphSCCPass.cpp - Pass that operates BU on call graph ---------===// +// +// This file implements the CallGraphSCCPass class, which is used for passes +// which are implemented as bottom-up traversals on the call graph. Because +// there may be cycles in the call graph, passes of this type operate on the +// call-graph in SCC order: that is, they process function bottom-up, except for +// recursive functions, which they process all at once. +// +//===----------------------------------------------------------------------===// + +#include "llvm/CallGraphSCCPass.h" +#include "llvm/Analysis/CallGraph.h" +#include "Support/TarjanSCCIterator.h" + +/// getAnalysisUsage - For this class, we declare that we require and preserve +/// the call graph. If the derived class implements this method, it should +/// always explicitly call the implementation here. +void CallGraphSCCPass::getAnalysisUsage(AnalysisUsage &AU) const { + AU.addRequired<CallGraph>(); + AU.addPreserved<CallGraph>(); +} + +bool CallGraphSCCPass::run(Module &M) { + CallGraph &CG = getAnalysis<CallGraph>(); + bool Changed = false; + for (TarjanSCC_iterator<CallGraph*> I = tarj_begin(&CG), E = tarj_end(&CG); + I != E; ++I) + Changed = runOnSCC(**I); + return Changed; +} |