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//===- InlineSimple.cpp - Code to perform simple function inlining --------===//
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// The LLVM Compiler Infrastructure
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//===----------------------------------------------------------------------===//
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// This file implements bottom-up inlining of functions into callees.
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//===----------------------------------------------------------------------===//
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#define DEBUG_TYPE "inline"
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#include "llvm/CallingConv.h"
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#include "llvm/Instructions.h"
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#include "llvm/IntrinsicInst.h"
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#include "llvm/Module.h"
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#include "llvm/Type.h"
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#include "llvm/Analysis/CallGraph.h"
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#include "llvm/Analysis/InlineCost.h"
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#include "llvm/Support/CallSite.h"
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#include "llvm/Transforms/IPO.h"
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#include "llvm/Transforms/IPO/InlinerPass.h"
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#include "llvm/ADT/SmallPtrSet.h"
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class SimpleInliner : public Inliner {
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// Functions that are never inlined
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SmallPtrSet<const Function*, 16> NeverInline;
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InlineCostAnalyzer CA;
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SimpleInliner() : Inliner(&ID) {}
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SimpleInliner(int Threshold) : Inliner(&ID, Threshold) {}
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static char ID; // Pass identification, replacement for typeid
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InlineCost getInlineCost(CallSite CS) {
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return CA.getInlineCost(CS, NeverInline);
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float getInlineFudgeFactor(CallSite CS) {
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return CA.getInlineFudgeFactor(CS);
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void resetCachedCostInfo(Function *Caller) {
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CA.resetCachedCostInfo(Caller);
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virtual bool doInitialization(CallGraph &CG);
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char SimpleInliner::ID = 0;
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static RegisterPass<SimpleInliner>
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X("inline", "Function Integration/Inlining");
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Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); }
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Pass *llvm::createFunctionInliningPass(int Threshold) {
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return new SimpleInliner(Threshold);
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// doInitialization - Initializes the vector of functions that have been
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// annotated with the noinline attribute.
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bool SimpleInliner::doInitialization(CallGraph &CG) {
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Module &M = CG.getModule();
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for (Module::iterator I = M.begin(), E = M.end();
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if (!I->isDeclaration() && I->hasFnAttr(Attribute::NoInline))
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NeverInline.insert(I);
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GlobalVariable *GV = M.getNamedGlobal("llvm.noinline");
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// Don't crash on invalid code
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if (!GV->hasDefinitiveInitializer())
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const ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer());
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// Iterate over each element and add to the NeverInline set
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for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
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const Constant *Elt = InitList->getOperand(i);
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if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(Elt))
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if (CE->getOpcode() == Instruction::BitCast)
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Elt = CE->getOperand(0);
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// Insert into set of functions to never inline
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if (const Function *F = dyn_cast<Function>(Elt))
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NeverInline.insert(F);