xref: /llvm-project/llvm/lib/Target/DirectX/DXILFinalizeLinkage.cpp (revision 3eca15cbb9888a992749ddd24f0fb666dad733bf)
1 //===- DXILFinalizeLinkage.cpp - Finalize linkage of functions ------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "DXILFinalizeLinkage.h"
10 #include "DirectX.h"
11 #include "llvm/IR/Function.h"
12 #include "llvm/IR/GlobalValue.h"
13 #include "llvm/IR/Metadata.h"
14 #include "llvm/IR/Module.h"
15 
16 #define DEBUG_TYPE "dxil-finalize-linkage"
17 
18 using namespace llvm;
19 
20 static bool finalizeLinkage(Module &M) {
21   SmallPtrSet<Function *, 8> Funcs;
22 
23   // Collect non-entry and non-exported functions to set to internal linkage.
24   for (Function &EF : M.functions()) {
25     if (EF.isIntrinsic())
26       continue;
27     if (EF.hasFnAttribute("hlsl.shader") || EF.hasFnAttribute("hlsl.export"))
28       continue;
29     Funcs.insert(&EF);
30   }
31 
32   for (Function *F : Funcs) {
33     if (F->getLinkage() == GlobalValue::ExternalLinkage)
34       F->setLinkage(GlobalValue::InternalLinkage);
35     if (F->isDefTriviallyDead())
36       M.getFunctionList().erase(F);
37   }
38 
39   return false;
40 }
41 
42 PreservedAnalyses DXILFinalizeLinkage::run(Module &M,
43                                            ModuleAnalysisManager &AM) {
44   if (finalizeLinkage(M))
45     return PreservedAnalyses::none();
46   return PreservedAnalyses::all();
47 }
48 
49 bool DXILFinalizeLinkageLegacy::runOnModule(Module &M) {
50   return finalizeLinkage(M);
51 }
52 
53 char DXILFinalizeLinkageLegacy::ID = 0;
54 
55 INITIALIZE_PASS_BEGIN(DXILFinalizeLinkageLegacy, DEBUG_TYPE,
56                       "DXIL Finalize Linkage", false, false)
57 INITIALIZE_PASS_END(DXILFinalizeLinkageLegacy, DEBUG_TYPE,
58                     "DXIL Finalize Linkage", false, false)
59 
60 ModulePass *llvm::createDXILFinalizeLinkageLegacyPass() {
61   return new DXILFinalizeLinkageLegacy();
62 }
63