1 //===- InlineAlways.cpp - Code to inline always_inline functions ----------===//
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 a custom inliner that handles only functions that
11 // are marked as "always inline".
12 //
13 //===----------------------------------------------------------------------===//
14
15 #define DEBUG_TYPE "inline"
16 #include "llvm/CallingConv.h"
17 #include "llvm/Instructions.h"
18 #include "llvm/IntrinsicInst.h"
19 #include "llvm/Module.h"
20 #include "llvm/Type.h"
21 #include "llvm/Analysis/CallGraph.h"
22 #include "llvm/Analysis/InlineCost.h"
23 #include "llvm/Support/CallSite.h"
24 #include "llvm/Transforms/IPO.h"
25 #include "llvm/Transforms/IPO/InlinerPass.h"
26 #include "llvm/Target/TargetData.h"
27 #include "llvm/ADT/SmallPtrSet.h"
28
29 using namespace llvm;
30
31 namespace {
32
33 // AlwaysInliner only inlines functions that are mark as "always inline".
34 class AlwaysInliner : public Inliner {
35 // Functions that are never inlined
36 SmallPtrSet<const Function*, 16> NeverInline;
37 InlineCostAnalyzer CA;
38 public:
39 // Use extremely low threshold.
AlwaysInliner()40 AlwaysInliner() : Inliner(ID, -2000000000) {
41 initializeAlwaysInlinerPass(*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 }
doFinalization(CallGraph & CG)56 virtual bool doFinalization(CallGraph &CG) {
57 return removeDeadFunctions(CG, &NeverInline);
58 }
59 virtual bool doInitialization(CallGraph &CG);
releaseMemory()60 void releaseMemory() {
61 CA.clear();
62 }
63 };
64 }
65
66 char AlwaysInliner::ID = 0;
67 INITIALIZE_PASS_BEGIN(AlwaysInliner, "always-inline",
68 "Inliner for always_inline functions", false, false)
INITIALIZE_AG_DEPENDENCY(CallGraph)69 INITIALIZE_AG_DEPENDENCY(CallGraph)
70 INITIALIZE_PASS_END(AlwaysInliner, "always-inline",
71 "Inliner for always_inline functions", false, false)
72
73 Pass *llvm::createAlwaysInlinerPass() { return new AlwaysInliner(); }
74
75 // doInitialization - Initializes the vector of functions that have not
76 // been annotated with the "always inline" attribute.
doInitialization(CallGraph & CG)77 bool AlwaysInliner::doInitialization(CallGraph &CG) {
78 CA.setTargetData(getAnalysisIfAvailable<TargetData>());
79
80 Module &M = CG.getModule();
81
82 for (Module::iterator I = M.begin(), E = M.end();
83 I != E; ++I)
84 if (!I->isDeclaration() && !I->hasFnAttr(Attribute::AlwaysInline))
85 NeverInline.insert(I);
86
87 return false;
88 }
89