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/Target/TargetData.h"
26 #include "llvm/ADT/SmallPtrSet.h"
32 class SimpleInliner : public Inliner {
33 // Functions that are never inlined
34 SmallPtrSet<const Function*, 16> NeverInline;
35 InlineCostAnalyzer CA;
37 SimpleInliner() : Inliner(ID) {
38 initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
40 SimpleInliner(int Threshold) : Inliner(ID, Threshold,
41 /*InsertLifetime*/true) {
42 initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
44 static char ID; // Pass identification, replacement for typeid
45 InlineCost getInlineCost(CallSite CS) {
46 // Filter out functions which should never be inlined due to the global
48 // FIXME: I'm 99% certain that this is an ancient bit of legacy that we
49 // no longer need to support, but I don't want to blindly nuke it just
51 if (Function *Callee = CS.getCalledFunction())
52 if (NeverInline.count(Callee))
53 return InlineCost::getNever();
55 return CA.getInlineCost(CS);
57 float getInlineFudgeFactor(CallSite CS) {
58 return CA.getInlineFudgeFactor(CS);
60 void resetCachedCostInfo(Function *Caller) {
61 CA.resetCachedCostInfo(Caller);
63 void growCachedCostInfo(Function* Caller, Function* Callee) {
64 CA.growCachedCostInfo(Caller, Callee);
66 virtual bool doInitialization(CallGraph &CG);
67 void releaseMemory() {
73 char SimpleInliner::ID = 0;
74 INITIALIZE_PASS_BEGIN(SimpleInliner, "inline",
75 "Function Integration/Inlining", false, false)
76 INITIALIZE_AG_DEPENDENCY(CallGraph)
77 INITIALIZE_PASS_END(SimpleInliner, "inline",
78 "Function Integration/Inlining", false, false)
80 Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); }
82 Pass *llvm::createFunctionInliningPass(int Threshold) {
83 return new SimpleInliner(Threshold);
86 // doInitialization - Initializes the vector of functions that have been
87 // annotated with the noinline attribute.
88 bool SimpleInliner::doInitialization(CallGraph &CG) {
89 CA.setTargetData(getAnalysisIfAvailable<TargetData>());
91 Module &M = CG.getModule();
94 GlobalVariable *GV = M.getNamedGlobal("llvm.noinline");
99 // Don't crash on invalid code
100 if (!GV->hasDefinitiveInitializer())
103 const ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer());
108 // Iterate over each element and add to the NeverInline set
109 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
112 const Constant *Elt = InitList->getOperand(i);
114 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(Elt))
115 if (CE->getOpcode() == Instruction::BitCast)
116 Elt = CE->getOperand(0);
118 // Insert into set of functions to never inline
119 if (const Function *F = dyn_cast<Function>(Elt))
120 NeverInline.insert(F);