1 //===-- AMDGPUAlwaysInlinePass.cpp - Promote Allocas ----------------------===//
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 /// \file
11 /// This pass marks all internal functions as always_inline and creates
12 /// duplicates of all other functions a marks the duplicates as always_inline.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #include "AMDGPU.h"
17 #include "llvm/IR/Module.h"
18 #include "llvm/Transforms/Utils/Cloning.h"
19 
20 using namespace llvm;
21 
22 namespace {
23 
24 class AMDGPUAlwaysInline : public ModulePass {
25   static char ID;
26 
27   bool GlobalOpt;
28 
29 public:
30   AMDGPUAlwaysInline(bool GlobalOpt) : ModulePass(ID), GlobalOpt(GlobalOpt) { }
31   bool runOnModule(Module &M) override;
32   StringRef getPassName() const override { return "AMDGPU Always Inline Pass"; }
33 };
34 
35 } // End anonymous namespace
36 
37 char AMDGPUAlwaysInline::ID = 0;
38 
39 bool AMDGPUAlwaysInline::runOnModule(Module &M) {
40   std::vector<GlobalAlias*> AliasesToRemove;
41   std::vector<Function *> FuncsToClone;
42 
43   for (GlobalAlias &A : M.aliases()) {
44     if (Function* F = dyn_cast<Function>(A.getAliasee())) {
45       A.replaceAllUsesWith(F);
46       AliasesToRemove.push_back(&A);
47     }
48   }
49 
50   if (GlobalOpt) {
51     for (GlobalAlias* A : AliasesToRemove) {
52       A->eraseFromParent();
53     }
54   }
55 
56   for (Function &F : M) {
57     if (!F.hasLocalLinkage() && !F.isDeclaration() && !F.use_empty() &&
58         !F.hasFnAttribute(Attribute::NoInline))
59       FuncsToClone.push_back(&F);
60   }
61 
62   for (Function *F : FuncsToClone) {
63     ValueToValueMapTy VMap;
64     Function *NewFunc = CloneFunction(F, VMap);
65     NewFunc->setLinkage(GlobalValue::InternalLinkage);
66     F->replaceAllUsesWith(NewFunc);
67   }
68 
69   for (Function &F : M) {
70     if (F.hasLocalLinkage() && !F.hasFnAttribute(Attribute::NoInline)) {
71       F.addFnAttr(Attribute::AlwaysInline);
72     }
73   }
74   return false;
75 }
76 
77 ModulePass *llvm::createAMDGPUAlwaysInlinePass(bool GlobalOpt) {
78   return new AMDGPUAlwaysInline(GlobalOpt);
79 }
80