1 //===- DXContainerGlobals.cpp - DXContainer global generator pass ---------===//
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 // DXContainerGlobalsPass implementation.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "DXILShaderFlags.h"
14 #include "DirectX.h"
15 #include "llvm/ADT/StringRef.h"
16 #include "llvm/BinaryFormat/DXContainer.h"
17 #include "llvm/CodeGen/Passes.h"
18 #include "llvm/IR/Constants.h"
19 #include "llvm/InitializePasses.h"
20 #include "llvm/Pass.h"
21 #include "llvm/Support/MD5.h"
22 #include "llvm/Transforms/Utils/ModuleUtils.h"
23
24 using namespace llvm;
25 using namespace llvm::dxil;
26
27 namespace {
28 class DXContainerGlobals : public llvm::ModulePass {
29
30 GlobalVariable *getShaderFlags(Module &M);
31 GlobalVariable *computeShaderHash(Module &M);
32
33 public:
34 static char ID; // Pass identification, replacement for typeid
DXContainerGlobals()35 DXContainerGlobals() : ModulePass(ID) {
36 initializeDXContainerGlobalsPass(*PassRegistry::getPassRegistry());
37 }
38
getPassName() const39 StringRef getPassName() const override {
40 return "DXContainer Global Emitter";
41 }
42
43 bool runOnModule(Module &M) override;
44
getAnalysisUsage(AnalysisUsage & AU) const45 void getAnalysisUsage(AnalysisUsage &AU) const override {
46 AU.setPreservesAll();
47 AU.addRequired<ShaderFlagsAnalysisWrapper>();
48 }
49 };
50
51 } // namespace
52
runOnModule(Module & M)53 bool DXContainerGlobals::runOnModule(Module &M) {
54 llvm::SmallVector<GlobalValue *> Globals;
55 Globals.push_back(getShaderFlags(M));
56 Globals.push_back(computeShaderHash(M));
57
58 appendToCompilerUsed(M, Globals);
59 return true;
60 }
61
getShaderFlags(Module & M)62 GlobalVariable *DXContainerGlobals::getShaderFlags(Module &M) {
63 const uint64_t Flags =
64 (uint64_t)(getAnalysis<ShaderFlagsAnalysisWrapper>().getShaderFlags());
65
66 Constant *FlagsConstant = ConstantInt::get(M.getContext(), APInt(64, Flags));
67 auto *GV = new llvm::GlobalVariable(M, FlagsConstant->getType(), true,
68 GlobalValue::PrivateLinkage,
69 FlagsConstant, "dx.sfi0");
70 GV->setSection("SFI0");
71 GV->setAlignment(Align(4));
72 return GV;
73 }
74
computeShaderHash(Module & M)75 GlobalVariable *DXContainerGlobals::computeShaderHash(Module &M) {
76 auto *DXILConstant =
77 cast<ConstantDataArray>(M.getNamedGlobal("dx.dxil")->getInitializer());
78 MD5 Digest;
79 Digest.update(DXILConstant->getRawDataValues());
80 MD5::MD5Result Result = Digest.final();
81
82 dxbc::ShaderHash HashData = {0, {0}};
83 // The Hash's IncludesSource flag gets set whenever the hashed shader includes
84 // debug information.
85 if (M.debug_compile_units_begin() != M.debug_compile_units_end())
86 HashData.Flags = static_cast<uint32_t>(dxbc::HashFlags::IncludesSource);
87
88 memcpy(reinterpret_cast<void *>(&HashData.Digest), Result.data(), 16);
89 if (sys::IsBigEndianHost)
90 HashData.swapBytes();
91 StringRef Data(reinterpret_cast<char *>(&HashData), sizeof(dxbc::ShaderHash));
92
93 Constant *ModuleConstant =
94 ConstantDataArray::get(M.getContext(), arrayRefFromStringRef(Data));
95 auto *GV = new llvm::GlobalVariable(M, ModuleConstant->getType(), true,
96 GlobalValue::PrivateLinkage,
97 ModuleConstant, "dx.hash");
98 GV->setSection("HASH");
99 GV->setAlignment(Align(4));
100 return GV;
101 }
102
103 char DXContainerGlobals::ID = 0;
104 INITIALIZE_PASS_BEGIN(DXContainerGlobals, "dxil-globals",
105 "DXContainer Global Emitter", false, true)
INITIALIZE_PASS_DEPENDENCY(ShaderFlagsAnalysisWrapper)106 INITIALIZE_PASS_DEPENDENCY(ShaderFlagsAnalysisWrapper)
107 INITIALIZE_PASS_END(DXContainerGlobals, "dxil-globals",
108 "DXContainer Global Emitter", false, true)
109
110 ModulePass *llvm::createDXContainerGlobalsPass() {
111 return new DXContainerGlobals();
112 }
113