1 //===- InlineSimple.cpp - Code to perform simple function inlining --------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements bottom-up inlining of functions into callees.
12 //===----------------------------------------------------------------------===//
14 #define DEBUG_TYPE "inline"
15 #include "llvm/CallingConv.h"
16 #include "llvm/Instructions.h"
17 #include "llvm/IntrinsicInst.h"
18 #include "llvm/Module.h"
19 #include "llvm/Type.h"
20 #include "llvm/Analysis/CallGraph.h"
21 #include "llvm/Analysis/InlineCost.h"
22 #include "llvm/Support/CallSite.h"
23 #include "llvm/Transforms/IPO.h"
24 #include "llvm/Transforms/IPO/InlinerPass.h"
25 #include "llvm/ADT/SmallPtrSet.h"
31 class SimpleInliner : public Inliner {
32 // Functions that are never inlined
33 SmallPtrSet<const Function*, 16> NeverInline;
34 InlineCostAnalyzer CA;
36 SimpleInliner() : Inliner(&ID) {}
37 SimpleInliner(int Threshold) : Inliner(&ID, Threshold) {}
38 static char ID; // Pass identification, replacement for typeid
39 InlineCost getInlineCost(CallSite CS) {
40 return CA.getInlineCost(CS, NeverInline);
42 float getInlineFudgeFactor(CallSite CS) {
43 return CA.getInlineFudgeFactor(CS);
45 void resetCachedCostInfo(Function *Caller) {
46 CA.resetCachedCostInfo(Caller);
48 virtual bool doInitialization(CallGraph &CG);
52 char SimpleInliner::ID = 0;
53 static RegisterPass<SimpleInliner>
54 X("inline", "Function Integration/Inlining");
56 Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); }
58 Pass *llvm::createFunctionInliningPass(int Threshold) {
59 return new SimpleInliner(Threshold);
62 // doInitialization - Initializes the vector of functions that have been
63 // annotated with the noinline attribute.
64 bool SimpleInliner::doInitialization(CallGraph &CG) {
66 Module &M = CG.getModule();
68 for (Module::iterator I = M.begin(), E = M.end();
70 if (!I->isDeclaration() && I->hasFnAttr(Attribute::NoInline))
71 NeverInline.insert(I);
74 GlobalVariable *GV = M.getNamedGlobal("llvm.noinline");
79 // Don't crash on invalid code
80 if (!GV->hasDefinitiveInitializer())
83 const ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer());
88 // Iterate over each element and add to the NeverInline set
89 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
92 const Constant *Elt = InitList->getOperand(i);
94 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(Elt))
95 if (CE->getOpcode() == Instruction::BitCast)
96 Elt = CE->getOperand(0);
98 // Insert into set of functions to never inline
99 if (const Function *F = dyn_cast<Function>(Elt))
100 NeverInline.insert(F);