1 //===- InlineSimple.cpp - Code to perform simple function inlining --------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements bottom-up inlining of functions into callees.
11 //
12 //===----------------------------------------------------------------------===//
13
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"
27
28 using namespace llvm;
29
30 namespace {
31
32 class SimpleInliner : public Inliner {
33 // Functions that are never inlined
34 SmallPtrSet<const Function*, 16> NeverInline;
35 InlineCostAnalyzer CA;
36 public:
SimpleInliner()37 SimpleInliner() : Inliner(ID) {
38 initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
39 }
SimpleInliner(int Threshold)40 SimpleInliner(int Threshold) : Inliner(ID, Threshold) {
41 initializeSimpleInlinerPass(*PassRegistry::getPassRegistry());
42 }
43 static char ID; // Pass identification, replacement for typeid
getInlineCost(CallSite CS)44 InlineCost getInlineCost(CallSite CS) {
45 return CA.getInlineCost(CS, NeverInline);
46 }
getInlineFudgeFactor(CallSite CS)47 float getInlineFudgeFactor(CallSite CS) {
48 return CA.getInlineFudgeFactor(CS);
49 }
resetCachedCostInfo(Function * Caller)50 void resetCachedCostInfo(Function *Caller) {
51 CA.resetCachedCostInfo(Caller);
52 }
growCachedCostInfo(Function * Caller,Function * Callee)53 void growCachedCostInfo(Function* Caller, Function* Callee) {
54 CA.growCachedCostInfo(Caller, Callee);
55 }
56 virtual bool doInitialization(CallGraph &CG);
releaseMemory()57 void releaseMemory() {
58 CA.clear();
59 }
60 };
61 }
62
63 char SimpleInliner::ID = 0;
64 INITIALIZE_PASS_BEGIN(SimpleInliner, "inline",
65 "Function Integration/Inlining", false, false)
INITIALIZE_AG_DEPENDENCY(CallGraph)66 INITIALIZE_AG_DEPENDENCY(CallGraph)
67 INITIALIZE_PASS_END(SimpleInliner, "inline",
68 "Function Integration/Inlining", false, false)
69
70 Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); }
71
createFunctionInliningPass(int Threshold)72 Pass *llvm::createFunctionInliningPass(int Threshold) {
73 return new SimpleInliner(Threshold);
74 }
75
76 // doInitialization - Initializes the vector of functions that have been
77 // annotated with the noinline attribute.
doInitialization(CallGraph & CG)78 bool SimpleInliner::doInitialization(CallGraph &CG) {
79 CA.setTargetData(getAnalysisIfAvailable<TargetData>());
80
81 Module &M = CG.getModule();
82
83 for (Module::iterator I = M.begin(), E = M.end();
84 I != E; ++I)
85 if (!I->isDeclaration() && I->hasFnAttr(Attribute::NoInline))
86 NeverInline.insert(I);
87
88 // Get llvm.noinline
89 GlobalVariable *GV = M.getNamedGlobal("llvm.noinline");
90
91 if (GV == 0)
92 return false;
93
94 // Don't crash on invalid code
95 if (!GV->hasDefinitiveInitializer())
96 return false;
97
98 const ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer());
99
100 if (InitList == 0)
101 return false;
102
103 // Iterate over each element and add to the NeverInline set
104 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
105
106 // Get Source
107 const Constant *Elt = InitList->getOperand(i);
108
109 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(Elt))
110 if (CE->getOpcode() == Instruction::BitCast)
111 Elt = CE->getOperand(0);
112
113 // Insert into set of functions to never inline
114 if (const Function *F = dyn_cast<Function>(Elt))
115 NeverInline.insert(F);
116 }
117
118 return false;
119 }
120
121