llvm/lib/Target/DirectX/DXILFinalizeLinkage.cpp

   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 }