From fa31d38aad0d919a84081b9f57c580e34d7cd92e Mon Sep 17 00:00:00 2001 From: Devang Patel Date: Thu, 10 Mar 2011 00:21:25 +0000 Subject: Introduce DebugInfoProbe. This is used to monitor how llvm optimizer is treating debugging information. It generates output that lools like 8 times line number info lost by Scalar Replacement of Aggregates (SSAUp) 1 times line number info lost by Simplify well-known library calls 12 times variable info lost by Jump Threading llvm-svn: 127381 --- llvm/lib/VMCore/DebugInfoProbe.cpp | 237 +++++++++++++++++++++++++++++++++++++ 1 file changed, 237 insertions(+) create mode 100644 llvm/lib/VMCore/DebugInfoProbe.cpp (limited to 'llvm/lib/VMCore/DebugInfoProbe.cpp') diff --git a/llvm/lib/VMCore/DebugInfoProbe.cpp b/llvm/lib/VMCore/DebugInfoProbe.cpp new file mode 100644 index 00000000000..4a5e659ef27 --- /dev/null +++ b/llvm/lib/VMCore/DebugInfoProbe.cpp @@ -0,0 +1,237 @@ +//===-- DebugInfoProbe.cpp - DebugInfo Probe ------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file implements DebugInfoProbe. This probe can be used by a pass +// manager to analyze how optimizer is treating debugging information. +// +//===----------------------------------------------------------------------===// + +#define DEBUG_TYPE "debuginfoprobe" +#include "llvm/DebugInfoProbe.h" +#include "llvm/Function.h" +#include "llvm/IntrinsicInst.h" +#include "llvm/Metadata.h" +#include "llvm/PassManager.h" +#include "llvm/Support/CommandLine.h" +#include "llvm/Support/Debug.h" +#include "llvm/Support/DebugLoc.h" +#include "llvm/Support/raw_ostream.h" +#include "llvm/ADT/StringRef.h" +#include +#include + +using namespace llvm; + +static cl::opt +EnableDebugInfoProbe("enable-debug-info-probe", cl::Hidden, + cl::desc("Enable debug info probe")); + +// CreateInfoOutputFile - Return a file stream to print our output on. +namespace llvm { extern raw_ostream *CreateInfoOutputFile(); } + +//===----------------------------------------------------------------------===// +// DebugInfoProbeImpl - This class implements a interface to monitor +// how an optimization pass is preserving debugging information. + +namespace llvm { + + class DebugInfoProbeImpl { + public: + DebugInfoProbeImpl() : NumDbgLineLost(0),NumDbgValueLost(0) {} + void initialize(StringRef PName, Function &F); + void finalize(Function &F); + void report(); + private: + unsigned NumDbgLineLost, NumDbgValueLost; + std::string PassName; + Function *TheFn; + std::set LineNos; + std::set DbgVariables; + }; +} + +//===----------------------------------------------------------------------===// +// DebugInfoProbeImpl + +static void collect(Function &F, std::set &Lines) { + for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE; ++FI) + for (BasicBlock::iterator BI = FI->begin(), BE = FI->end(); + BI != BE; ++BI) { + const DebugLoc &DL = BI->getDebugLoc(); + unsigned LineNo = 0; + if (!DL.isUnknown()) { + if (MDNode *N = DL.getInlinedAt(F.getContext())) + LineNo = DebugLoc::getFromDILocation(N).getLine(); + else + LineNo = DL.getLine(); + + Lines.insert(LineNo); + } + } +} + +/// initialize - Collect information before running an optimization pass. +void DebugInfoProbeImpl::initialize(StringRef PName, Function &F) { + if (!EnableDebugInfoProbe) return; + PassName = PName; + NumDbgLineLost = 0; + NumDbgValueLost = 0; + + LineNos.clear(); + DbgVariables.clear(); + TheFn = &F; + collect(F, LineNos); + + for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE; ++FI) + for (BasicBlock::iterator BI = FI->begin(), BE = FI->end(); + BI != BE; ++BI) { + if (!isa(BI)) continue; + Value *Addr = NULL; + MDNode *Node = NULL; + if (DbgDeclareInst *DDI = dyn_cast(BI)) { + Addr = DDI->getAddress(); + Node = DDI->getVariable(); + } else if (DbgValueInst *DVI = dyn_cast(BI)) { + Addr = DVI->getValue(); + Node = DVI->getVariable(); + } + if (Addr) continue; + DbgVariables.insert(Node); + } +} + +/// report - Report findings. This should be invoked after finalize. +void DebugInfoProbeImpl::report() { + if (!EnableDebugInfoProbe) return; + if (NumDbgLineLost || NumDbgValueLost) { + raw_ostream *OutStream = CreateInfoOutputFile(); + if (NumDbgLineLost) + *OutStream << NumDbgLineLost + << "\t times line number info lost by " + << PassName << "\n"; + if (NumDbgValueLost) + *OutStream << NumDbgValueLost + << "\t times variable info lost by " + << PassName << "\n"; + delete OutStream; + } +} + +/// finalize - Collect information after running an optimization pass. This +/// must be used after initialization. +void DebugInfoProbeImpl::finalize(Function &F) { + if (!EnableDebugInfoProbe) return; + std::set LineNos2; + collect(F, LineNos2); + assert (TheFn == &F && "Invalid function to measure!"); + + for (std::set::iterator I = LineNos.begin(), + E = LineNos.end(); I != E; ++I) { + unsigned LineNo = *I; + if (LineNos2.count(LineNo) == 0) { + DEBUG(dbgs() << "Losing dbg info intrinsic at line " << LineNo << " "); + ++NumDbgLineLost; + } + } + + std::setDbgVariables2; + for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE; ++FI) + for (BasicBlock::iterator BI = FI->begin(), BE = FI->end(); + BI != BE; ++BI) { + if (!isa(BI)) continue; + Value *Addr = NULL; + MDNode *Node = NULL; + if (DbgDeclareInst *DDI = dyn_cast(BI)) { + Addr = DDI->getAddress(); + Node = DDI->getVariable(); + } else if (DbgValueInst *DVI = dyn_cast(BI)) { + Addr = DVI->getValue(); + Node = DVI->getVariable(); + } + if (Addr) continue; + DbgVariables2.insert(Node); + } + + for (std::set::iterator I = DbgVariables.begin(), + E = DbgVariables.end(); I != E; ++I) { + if (DbgVariables2.count(*I) == 0) { + DEBUG(dbgs() << "Losing dbg info for variable: "); + DEBUG((*I)->print(dbgs())); + ++NumDbgValueLost; + } + } +} + +//===----------------------------------------------------------------------===// +// DebugInfoProbe + +DebugInfoProbe::DebugInfoProbe() { + pImpl = new DebugInfoProbeImpl(); +} + +DebugInfoProbe::~DebugInfoProbe() { + delete pImpl; +} + +/// initialize - Collect information before running an optimization pass. +void DebugInfoProbe::initialize(StringRef PName, Function &F) { + pImpl->initialize(PName, F); +} + +/// finalize - Collect information after running an optimization pass. This +/// must be used after initialization. +void DebugInfoProbe::finalize(Function &F) { + pImpl->finalize(F); +} + +/// report - Report findings. This should be invoked after finalize. +void DebugInfoProbe::report() { + pImpl->report(); +} + +//===----------------------------------------------------------------------===// +// DebugInfoProbeInfo + +/// ~DebugInfoProbeInfo - Report data collected by all probes before deleting +/// them. +DebugInfoProbeInfo::~DebugInfoProbeInfo() { + if (!EnableDebugInfoProbe) return; + for (StringMap::iterator I = Probes.begin(), + E = Probes.end(); I != E; ++I) { + I->second->report(); + delete I->second; + } + } + +/// initialize - Collect information before running an optimization pass. +void DebugInfoProbeInfo::initialize(Pass *P, Function &F) { + if (!EnableDebugInfoProbe) return; + if (P->getAsPMDataManager()) + return; + + StringMapEntry &Entry = + Probes.GetOrCreateValue(P->getPassName()); + DebugInfoProbe *&Probe = Entry.getValue(); + if (!Probe) + Probe = new DebugInfoProbe(); + Probe->initialize(P->getPassName(), F); +} + +/// finalize - Collect information after running an optimization pass. This +/// must be used after initialization. +void DebugInfoProbeInfo::finalize(Pass *P, Function &F) { + if (!EnableDebugInfoProbe) return; + if (P->getAsPMDataManager()) + return; + StringMapEntry &Entry = + Probes.GetOrCreateValue(P->getPassName()); + DebugInfoProbe *&Probe = Entry.getValue(); + assert (Probe && "DebugInfoProbe is not initialized!"); + Probe->finalize(F); +} -- cgit v1.2.3