1 //===- InlineAlways.cpp - Code to inline always_inline functions ----------===//
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 a custom inliner that handles only functions that
11 // are marked as "always inline".
13 //===----------------------------------------------------------------------===//
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"
33 // AlwaysInliner only inlines functions that are mark as "always inline".
34 class AlwaysInliner : public Inliner {
35 InlineCostAnalyzer CA;
37 // Use extremely low threshold.
38 AlwaysInliner() : Inliner(ID, -2000000000, /*InsertLifetime*/true) {
39 initializeAlwaysInlinerPass(*PassRegistry::getPassRegistry());
41 AlwaysInliner(bool InsertLifetime) : Inliner(ID, -2000000000,
43 initializeAlwaysInlinerPass(*PassRegistry::getPassRegistry());
45 static char ID; // Pass identification, replacement for typeid
46 InlineCost getInlineCost(CallSite CS) {
47 Function *Callee = CS.getCalledFunction();
48 // We assume indirect calls aren't calling an always-inline function.
49 if (!Callee) return InlineCost::getNever();
51 // We can't inline calls to external functions.
52 // FIXME: We shouldn't even get here.
53 if (Callee->isDeclaration()) return InlineCost::getNever();
55 // Return never for anything not marked as always inline.
56 if (!Callee->hasFnAttr(Attribute::AlwaysInline))
57 return InlineCost::getNever();
59 // We still have to check the inline cost in case there are reasons to
60 // not inline which trump the always-inline attribute such as setjmp and
62 return CA.getInlineCost(CS, getInlineThreshold(CS));
64 virtual bool doFinalization(CallGraph &CG) {
65 return removeDeadFunctions(CG, /*AlwaysInlineOnly=*/true);
67 virtual bool doInitialization(CallGraph &CG);
71 char AlwaysInliner::ID = 0;
72 INITIALIZE_PASS_BEGIN(AlwaysInliner, "always-inline",
73 "Inliner for always_inline functions", false, false)
74 INITIALIZE_AG_DEPENDENCY(CallGraph)
75 INITIALIZE_PASS_END(AlwaysInliner, "always-inline",
76 "Inliner for always_inline functions", false, false)
78 Pass *llvm::createAlwaysInlinerPass() { return new AlwaysInliner(); }
80 Pass *llvm::createAlwaysInlinerPass(bool InsertLifetime) {
81 return new AlwaysInliner(InsertLifetime);
84 // doInitialization - Initializes the vector of functions that have not
85 // been annotated with the "always inline" attribute.
86 bool AlwaysInliner::doInitialization(CallGraph &CG) {
87 CA.setTargetData(getAnalysisIfAvailable<TargetData>());