1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
|
//===- DXILPrepare.cpp - Prepare LLVM Module for DXIL encoding ------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
///
/// \file This file contains pases and utilities to convert a modern LLVM
/// module into a module compatible with the LLVM 3.7-based DirectX Intermediate
/// Language (DXIL).
//===----------------------------------------------------------------------===//
#include "DirectX.h"
#include "DirectXIRPasses/PointerTypeAnalysis.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/Module.h"
#include "llvm/InitializePasses.h"
#include "llvm/Pass.h"
#include "llvm/Support/Compiler.h"
#define DEBUG_TYPE "dxil-prepare"
using namespace llvm;
using namespace llvm::dxil;
namespace {
constexpr bool isValidForDXIL(Attribute::AttrKind Attr) {
return is_contained({Attribute::Alignment,
Attribute::AlwaysInline,
Attribute::Builtin,
Attribute::ByVal,
Attribute::InAlloca,
Attribute::Cold,
Attribute::Convergent,
Attribute::InlineHint,
Attribute::InReg,
Attribute::JumpTable,
Attribute::MinSize,
Attribute::Naked,
Attribute::Nest,
Attribute::NoAlias,
Attribute::NoBuiltin,
Attribute::NoCapture,
Attribute::NoDuplicate,
Attribute::NoImplicitFloat,
Attribute::NoInline,
Attribute::NonLazyBind,
Attribute::NonNull,
Attribute::Dereferenceable,
Attribute::DereferenceableOrNull,
Attribute::Memory,
Attribute::NoRedZone,
Attribute::NoReturn,
Attribute::NoUnwind,
Attribute::OptimizeForSize,
Attribute::OptimizeNone,
Attribute::ReadNone,
Attribute::ReadOnly,
Attribute::Returned,
Attribute::ReturnsTwice,
Attribute::SExt,
Attribute::StackAlignment,
Attribute::StackProtect,
Attribute::StackProtectReq,
Attribute::StackProtectStrong,
Attribute::SafeStack,
Attribute::StructRet,
Attribute::SanitizeAddress,
Attribute::SanitizeThread,
Attribute::SanitizeMemory,
Attribute::UWTable,
Attribute::ZExt},
Attr);
}
class DXILPrepareModule : public ModulePass {
static Value *maybeGenerateBitcast(IRBuilder<> &Builder,
PointerTypeMap &PointerTypes,
Instruction &Inst, Value *Operand,
Type *Ty) {
// Omit bitcasts if the incoming value matches the instruction type.
auto It = PointerTypes.find(Operand);
if (It != PointerTypes.end())
if (cast<TypedPointerType>(It->second)->getElementType() == Ty)
return nullptr;
// Insert bitcasts where we are removing the instruction.
Builder.SetInsertPoint(&Inst);
// This code only gets hit in opaque-pointer mode, so the type of the
// pointer doesn't matter.
PointerType *PtrTy = cast<PointerType>(Operand->getType());
return Builder.Insert(
CastInst::Create(Instruction::BitCast, Operand,
Builder.getInt8PtrTy(PtrTy->getAddressSpace())));
}
public:
bool runOnModule(Module &M) override {
PointerTypeMap PointerTypes = PointerTypeAnalysis::run(M);
AttributeMask AttrMask;
for (Attribute::AttrKind I = Attribute::None; I != Attribute::EndAttrKinds;
I = Attribute::AttrKind(I + 1)) {
if (!isValidForDXIL(I))
AttrMask.addAttribute(I);
}
for (auto &F : M.functions()) {
F.removeFnAttrs(AttrMask);
F.removeRetAttrs(AttrMask);
for (size_t Idx = 0, End = F.arg_size(); Idx < End; ++Idx)
F.removeParamAttrs(Idx, AttrMask);
for (auto &BB : F) {
IRBuilder<> Builder(&BB);
for (auto &I : make_early_inc_range(BB)) {
if (I.getOpcode() == Instruction::FNeg) {
Builder.SetInsertPoint(&I);
Value *In = I.getOperand(0);
Value *Zero = ConstantFP::get(In->getType(), -0.0);
I.replaceAllUsesWith(Builder.CreateFSub(Zero, In));
I.eraseFromParent();
continue;
}
// Only insert bitcasts if the IR is using opaque pointers.
if (M.getContext().supportsTypedPointers())
continue;
// Emtting NoOp bitcast instructions allows the ValueEnumerator to be
// unmodified as it reserves instruction IDs during contruction.
if (auto LI = dyn_cast<LoadInst>(&I)) {
if (Value *NoOpBitcast = maybeGenerateBitcast(
Builder, PointerTypes, I, LI->getPointerOperand(),
LI->getType())) {
LI->replaceAllUsesWith(
Builder.CreateLoad(LI->getType(), NoOpBitcast));
LI->eraseFromParent();
}
continue;
}
if (auto SI = dyn_cast<StoreInst>(&I)) {
if (Value *NoOpBitcast = maybeGenerateBitcast(
Builder, PointerTypes, I, SI->getPointerOperand(),
SI->getValueOperand()->getType())) {
SI->replaceAllUsesWith(
Builder.CreateStore(SI->getValueOperand(), NoOpBitcast));
SI->eraseFromParent();
}
continue;
}
if (auto GEP = dyn_cast<GetElementPtrInst>(&I)) {
if (Value *NoOpBitcast = maybeGenerateBitcast(
Builder, PointerTypes, I, GEP->getPointerOperand(),
GEP->getResultElementType()))
GEP->setOperand(0, NoOpBitcast);
continue;
}
if (auto *CB = dyn_cast<CallBase>(&I)) {
CB->removeFnAttrs(AttrMask);
CB->removeRetAttrs(AttrMask);
for (size_t Idx = 0, End = CB->arg_size(); Idx < End; ++Idx)
CB->removeParamAttrs(Idx, AttrMask);
continue;
}
}
}
}
return true;
}
DXILPrepareModule() : ModulePass(ID) {}
static char ID; // Pass identification.
};
char DXILPrepareModule::ID = 0;
} // end anonymous namespace
INITIALIZE_PASS_BEGIN(DXILPrepareModule, DEBUG_TYPE, "DXIL Prepare Module",
false, false)
INITIALIZE_PASS_END(DXILPrepareModule, DEBUG_TYPE, "DXIL Prepare Module", false,
false)
ModulePass *llvm::createDXILPrepareModulePass() {
return new DXILPrepareModule();
}
|
