1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
|
//===- InlineAlways.cpp - Code to inline always_inline functions ----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements a custom inliner that handles only functions that
// are marked as "always inline".
//
//===----------------------------------------------------------------------===//
#include "llvm/Transforms/IPO/AlwaysInliner.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/CallGraph.h"
#include "llvm/Analysis/InlineCost.h"
#include "llvm/Analysis/ProfileSummaryInfo.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/CallingConv.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Type.h"
#include "llvm/Transforms/IPO/InlinerPass.h"
#include "llvm/Transforms/Utils/Cloning.h"
using namespace llvm;
#define DEBUG_TYPE "inline"
PreservedAnalyses AlwaysInlinerPass::run(Module &M, ModuleAnalysisManager &) {
InlineFunctionInfo IFI;
SmallSetVector<CallSite, 16> Calls;
bool Changed = false;
for (Function &F : M)
if (!F.isDeclaration() && F.hasFnAttribute(Attribute::AlwaysInline) &&
isInlineViable(F)) {
Calls.clear();
for (User *U : F.users())
if (auto CS = CallSite(U))
if (CS.getCalledFunction() == &F)
Calls.insert(CS);
for (CallSite CS : Calls)
// FIXME: We really shouldn't be able to fail to inline at this point!
// We should do something to log or check the inline failures here.
Changed |= InlineFunction(CS, IFI);
}
return Changed ? PreservedAnalyses::none() : PreservedAnalyses::all();
}
namespace {
/// Inliner pass which only handles "always inline" functions.
///
/// Unlike the \c AlwaysInlinerPass, this uses the more heavyweight \c Inliner
/// base class to provide several facilities such as array alloca merging.
class AlwaysInlinerLegacyPass : public Inliner {
public:
AlwaysInlinerLegacyPass() : Inliner(ID, /*InsertLifetime*/ true) {
initializeAlwaysInlinerLegacyPassPass(*PassRegistry::getPassRegistry());
}
AlwaysInlinerLegacyPass(bool InsertLifetime) : Inliner(ID, InsertLifetime) {
initializeAlwaysInlinerLegacyPassPass(*PassRegistry::getPassRegistry());
}
/// Main run interface method. We override here to avoid calling skipSCC().
bool runOnSCC(CallGraphSCC &SCC) override { return inlineCalls(SCC); }
static char ID; // Pass identification, replacement for typeid
InlineCost getInlineCost(CallSite CS) override;
using llvm::Pass::doFinalization;
bool doFinalization(CallGraph &CG) override {
return removeDeadFunctions(CG, /*AlwaysInlineOnly=*/true);
}
};
}
char AlwaysInlinerLegacyPass::ID = 0;
INITIALIZE_PASS_BEGIN(AlwaysInlinerLegacyPass, "always-inline",
"Inliner for always_inline functions", false, false)
INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
INITIALIZE_PASS_DEPENDENCY(ProfileSummaryInfoWrapperPass)
INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
INITIALIZE_PASS_END(AlwaysInlinerLegacyPass, "always-inline",
"Inliner for always_inline functions", false, false)
Pass *llvm::createAlwaysInlinerLegacyPass(bool InsertLifetime) {
return new AlwaysInlinerLegacyPass(InsertLifetime);
}
/// \brief Get the inline cost for the always-inliner.
///
/// The always inliner *only* handles functions which are marked with the
/// attribute to force inlining. As such, it is dramatically simpler and avoids
/// using the powerful (but expensive) inline cost analysis. Instead it uses
/// a very simple and boring direct walk of the instructions looking for
/// impossible-to-inline constructs.
///
/// Note, it would be possible to go to some lengths to cache the information
/// computed here, but as we only expect to do this for relatively few and
/// small functions which have the explicit attribute to force inlining, it is
/// likely not worth it in practice.
InlineCost AlwaysInlinerLegacyPass::getInlineCost(CallSite CS) {
Function *Callee = CS.getCalledFunction();
// Only inline direct calls to functions with always-inline attributes
// that are viable for inlining. FIXME: We shouldn't even get here for
// declarations.
if (Callee && !Callee->isDeclaration() &&
CS.hasFnAttr(Attribute::AlwaysInline) && isInlineViable(*Callee))
return InlineCost::getAlways();
return InlineCost::getNever();
}
|
