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   bool GlobalOpt;
26 
27 public:
28   static char ID;
29 
30   AMDGPUAlwaysInline(bool GlobalOpt = false) :
31     ModulePass(ID), GlobalOpt(GlobalOpt) { }
32   bool runOnModule(Module &M) override;
33   StringRef getPassName() const override { return "AMDGPU Always Inline Pass"; }
34 };
35 
36 } // End anonymous namespace
37 
38 INITIALIZE_PASS(AMDGPUAlwaysInline, "amdgpu-always-inline",
39                 "AMDGPU Inline All Functions", false, false)
40 
41 char AMDGPUAlwaysInline::ID = 0;
42 
43 bool AMDGPUAlwaysInline::runOnModule(Module &M) {
44   std::vector<GlobalAlias*> AliasesToRemove;
45   std::vector<Function *> FuncsToClone;
46 
47   for (GlobalAlias &A : M.aliases()) {
48     if (Function* F = dyn_cast<Function>(A.getAliasee())) {
49       A.replaceAllUsesWith(F);
50       AliasesToRemove.push_back(&A);
51     }
52   }
53 
54   if (GlobalOpt) {
55     for (GlobalAlias* A : AliasesToRemove) {
56       A->eraseFromParent();
57     }
58   }
59 
60   for (Function &F : M) {
61     if (!F.hasLocalLinkage() && !F.isDeclaration() && !F.use_empty() &&
62         !F.hasFnAttribute(Attribute::NoInline))
63       FuncsToClone.push_back(&F);
64   }
65 
66   for (Function *F : FuncsToClone) {
67     ValueToValueMapTy VMap;
68     Function *NewFunc = CloneFunction(F, VMap);
69     NewFunc->setLinkage(GlobalValue::InternalLinkage);
70     F->replaceAllUsesWith(NewFunc);
71   }
72 
73   for (Function &F : M) {
74     if (F.hasLocalLinkage() && !F.hasFnAttribute(Attribute::NoInline)) {
75       F.addFnAttr(Attribute::AlwaysInline);
76     }
77   }
78   return false;
79 }
80 
81 ModulePass *llvm::createAMDGPUAlwaysInlinePass(bool GlobalOpt) {
82   return new AMDGPUAlwaysInline(GlobalOpt);
83 }
84