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237ef567f6
* Separate the policy decisions into a derived class [InlineSimple]
* Move the inlining mechanics into a base class [Inliner]
* Change the inliner to be an SCCPass, making it more structured and
eventually pipelinable with other SCC passes
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@8257 91177308-0d34-0410-b5e6-96231b3b80d8
120 lines
4.5 KiB
C++
120 lines
4.5 KiB
C++
//===- InlineCommon.cpp - Code common to all inliners ---------------------===//
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//
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// This file implements the code shared between the LLVM inliners. This
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// implements all of the boring mechanics of the bottom-up inlining.
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//
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//===----------------------------------------------------------------------===//
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#include "Inliner.h"
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#include "llvm/Module.h"
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#include "llvm/iOther.h"
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#include "llvm/iTerminators.h"
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#include "llvm/Analysis/CallGraph.h"
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#include "llvm/Support/CallSite.h"
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#include "llvm/Transforms/Utils/Cloning.h"
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#include "Support/CommandLine.h"
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#include "Support/Debug.h"
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#include "Support/Statistic.h"
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namespace {
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Statistic<> NumInlined("inline", "Number of functions inlined");
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Statistic<> NumDeleted("inline", "Number of functions deleted because all callers found");
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cl::opt<unsigned> // FIXME: 200 is VERY conservative
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InlineLimit("inline-threshold", cl::Hidden, cl::init(200),
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cl::desc("Control the amount of inlining to perform (default = 200)"));
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}
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Inliner::Inliner() : InlineThreshold(InlineLimit) {}
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int Inliner::getRecursiveInlineCost(CallSite CS) {
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return getInlineCost(CS);
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}
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bool Inliner::runOnSCC(const std::vector<CallGraphNode*> &SCC) {
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CallGraph &CG = getAnalysis<CallGraph>();
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std::set<Function*> SCCFunctions;
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DEBUG(std::cerr << "Inliner visiting SCC:");
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for (unsigned i = 0, e = SCC.size(); i != e; ++i) {
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SCCFunctions.insert(SCC[i]->getFunction());
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DEBUG(std::cerr << " " << (SCC[i]->getFunction() ?
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SCC[i]->getFunction()->getName() : "INDIRECTNODE"));
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}
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DEBUG(std::cerr << "\n");
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bool Changed = false;
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for (std::set<Function*>::iterator SCCI = SCCFunctions.begin(),
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E = SCCFunctions.end(); SCCI != E; ++SCCI) {
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Function *F = *SCCI;
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if (F == 0 || F->isExternal()) continue;
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DEBUG(std::cerr << " Inspecting function: " << F->getName() << "\n");
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for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
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for (BasicBlock::iterator I = BB->begin(); I != BB->end(); ) {
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bool ShouldInc = true;
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// Found a call or invoke instruction?
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if (isa<CallInst>(I) || isa<InvokeInst>(I)) {
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CallSite CS = CallSite::get(I);
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if (Function *Callee = CS.getCalledFunction())
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if (!Callee->isExternal()) {
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// Determine whether this is a function IN the SCC...
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bool inSCC = SCCFunctions.count(Callee);
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// If the policy determines that we should inline this function,
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// try to do so...
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int InlineCost = inSCC ? getRecursiveInlineCost(CS) :
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getInlineCost(CS);
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if (InlineCost < (int)InlineThreshold) {
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DEBUG(std::cerr << " Inlining: cost=" << InlineCost
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<< ", Call: " << *CS.getInstruction());
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// Save an iterator to the instruction before the call if it
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// exists, otherwise get an iterator at the end of the
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// block... because the call will be destroyed.
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//
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BasicBlock::iterator SI;
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if (I != BB->begin()) {
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SI = I; --SI; // Instruction before the call...
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} else {
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SI = BB->end();
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}
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if (performInlining(CS, SCCFunctions)) {
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// Move to instruction before the call...
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I = (SI == BB->end()) ? BB->begin() : SI;
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ShouldInc = false; // Don't increment iterator until next time
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Changed = true;
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}
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}
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}
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}
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if (ShouldInc) ++I;
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}
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}
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return Changed;
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}
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bool Inliner::performInlining(CallSite CS, std::set<Function*> &SCC) {
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Function *Callee = CS.getCalledFunction();
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Function *Caller = CS.getInstruction()->getParent()->getParent();
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// Attempt to inline the function...
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if (!InlineFunction(CS)) return false;
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++NumInlined;
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// If we inlined the last possible call site to the function,
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// delete the function body now.
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if (Callee->use_empty() && Callee != Caller &&
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(Callee->hasInternalLinkage() || Callee->hasLinkOnceLinkage())) {
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DEBUG(std::cerr << " -> Deleting dead function: "
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<< Callee->getName() << "\n");
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std::set<Function*>::iterator I = SCC.find(Callee);
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if (I != SCC.end()) // Remove function from this SCC...
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SCC.erase(I);
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Callee->getParent()->getFunctionList().erase(Callee);
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++NumDeleted;
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}
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return true;
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}
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