InlineAlways.cpp revision de4982c2dd800824f5f95d724173699326191a36 
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/Support/CallSite.h"
23#include "llvm/Support/Compiler.h"
24#include "llvm/Transforms/IPO.h"
25#include "llvm/Transforms/IPO/InlinerPass.h"
26#include "llvm/Transforms/Utils/InlineCost.h"
27#include "llvm/ADT/SmallPtrSet.h"
28
29using namespace llvm;
30
31namespace {
32
33  // AlwaysInliner only inlines functions that are mark as "always inline".
34  class VISIBILITY_HIDDEN 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.
40    AlwaysInliner() : Inliner(&ID, -2000000000) {}
41    static char ID; // Pass identification, replacement for typeid
42    InlineCost getInlineCost(CallSite CS) {
43      return CA.getInlineCost(CS, NeverInline);
44    }
45    float getInlineFudgeFactor(CallSite CS) {
46      return CA.getInlineFudgeFactor(CS);
47    }
48    virtual bool doInitialization(CallGraph &CG);
49  };
50}
51
52char AlwaysInliner::ID = 0;
53static RegisterPass<AlwaysInliner>
54X("always-inline", "Inliner for always_inline functions");
55
56Pass *llvm::createAlwaysInlinerPass() { return new AlwaysInliner(); }
57
58// doInitialization - Initializes the vector of functions that have not
59// been annotated with the "always inline" attribute.
60bool AlwaysInliner::doInitialization(CallGraph &CG) {
61  Module &M = CG.getModule();
62
63  for (Module::iterator I = M.begin(), E = M.end();
64       I != E; ++I)
65    if (!I->isDeclaration() && !I->hasFnAttr(Attribute::AlwaysInline))
66      NeverInline.insert(I);
67
68  return false;
69}
70