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/StringExtras.h"
16#include "llvm/ADT/StringRef.h"
17#include "llvm/BinaryFormat/DXContainer.h"
18#include "llvm/CodeGen/Passes.h"
19#include "llvm/IR/Constants.h"
20#include "llvm/InitializePasses.h"
21#include "llvm/Pass.h"
22#include "llvm/Support/MD5.h"
23#include "llvm/Transforms/Utils/ModuleUtils.h"
24
25using namespace llvm;
26using namespace llvm::dxil;
27
28namespace {
29class DXContainerGlobals : public llvm::ModulePass {
30
31 GlobalVariable *getFeatureFlags(Module &M);
32 GlobalVariable *computeShaderHash(Module &M);
33
34public:
35 static char ID; // Pass identification, replacement for typeid
36 DXContainerGlobals() : ModulePass(ID) {
37 initializeDXContainerGlobalsPass(*PassRegistry::getPassRegistry());
38 }
39
40 StringRef getPassName() const override {
41 return "DXContainer Global Emitter";
42 }
43
44 bool runOnModule(Module &M) override;
45
46 void getAnalysisUsage(AnalysisUsage &AU) const override {
47 AU.setPreservesAll();
48 AU.addRequired<ShaderFlagsAnalysisWrapper>();
49 }
50};
51
52} // namespace
53
54bool DXContainerGlobals::runOnModule(Module &M) {
55 llvm::SmallVector<GlobalValue *> Globals;
56 Globals.push_back(Elt: getFeatureFlags(M));
57 Globals.push_back(Elt: computeShaderHash(M));
58
59 appendToCompilerUsed(M, Values: Globals);
60 return true;
61}
62
63GlobalVariable *DXContainerGlobals::getFeatureFlags(Module &M) {
64 const uint64_t FeatureFlags =
65 static_cast<uint64_t>(getAnalysis<ShaderFlagsAnalysisWrapper>()
66 .getShaderFlags()
67 .getFeatureFlags());
68
69 Constant *FeatureFlagsConstant =
70 ConstantInt::get(Context&: M.getContext(), V: APInt(64, FeatureFlags));
71 auto *GV = new llvm::GlobalVariable(M, FeatureFlagsConstant->getType(), true,
72 GlobalValue::PrivateLinkage,
73 FeatureFlagsConstant, "dx.sfi0");
74 GV->setSection("SFI0");
75 GV->setAlignment(Align(4));
76 return GV;
77}
78
79GlobalVariable *DXContainerGlobals::computeShaderHash(Module &M) {
80 auto *DXILConstant =
81 cast<ConstantDataArray>(Val: M.getNamedGlobal(Name: "dx.dxil")->getInitializer());
82 MD5 Digest;
83 Digest.update(Str: DXILConstant->getRawDataValues());
84 MD5::MD5Result Result = Digest.final();
85
86 dxbc::ShaderHash HashData = {.Flags: 0, .Digest: {0}};
87 // The Hash's IncludesSource flag gets set whenever the hashed shader includes
88 // debug information.
89 if (M.debug_compile_units_begin() != M.debug_compile_units_end())
90 HashData.Flags = static_cast<uint32_t>(dxbc::HashFlags::IncludesSource);
91
92 memcpy(dest: reinterpret_cast<void *>(&HashData.Digest), src: Result.data(), n: 16);
93 if (sys::IsBigEndianHost)
94 HashData.swapBytes();
95 StringRef Data(reinterpret_cast<char *>(&HashData), sizeof(dxbc::ShaderHash));
96
97 Constant *ModuleConstant =
98 ConstantDataArray::get(Context&: M.getContext(), Elts: arrayRefFromStringRef(Input: Data));
99 auto *GV = new llvm::GlobalVariable(M, ModuleConstant->getType(), true,
100 GlobalValue::PrivateLinkage,
101 ModuleConstant, "dx.hash");
102 GV->setSection("HASH");
103 GV->setAlignment(Align(4));
104 return GV;
105}
106
107char DXContainerGlobals::ID = 0;
108INITIALIZE_PASS_BEGIN(DXContainerGlobals, "dxil-globals",
109 "DXContainer Global Emitter", false, true)
110INITIALIZE_PASS_DEPENDENCY(ShaderFlagsAnalysisWrapper)
111INITIALIZE_PASS_END(DXContainerGlobals, "dxil-globals",
112 "DXContainer Global Emitter", false, true)
113
114ModulePass *llvm::createDXContainerGlobalsPass() {
115 return new DXContainerGlobals();
116}
117

source code of llvm/lib/Target/DirectX/DXContainerGlobals.cpp