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
192
193
194
195
196
197
198
199
|
/*========================== begin_copyright_notice ============================
Copyright (C) 2021 Intel Corporation
SPDX-License-Identifier: MIT
============================= end_copyright_notice ===========================*/
#include "common/debug/Debug.hpp"
#include "common/debug/Dump.hpp"
#include "common/Stats.hpp"
#include "common/LLVMUtils.h"
#include "common/LLVMWarningsPush.hpp"
#include "llvm/IR/Dominators.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/CFG.h"
#include "llvm/ADT/PostOrderIterator.h"
#include "common/LLVMWarningsPop.hpp"
#include "Compiler/CodeGenPublic.h"
#include "Compiler/CISACodeGen/AddressArithmeticSinking.hpp"
#include "Compiler/CISACodeGen/helper.h"
#include "Compiler/CISACodeGen/ShaderCodeGen.hpp"
#include "Compiler/IGCPassSupport.h"
#include "Probe/Assertion.h"
#include <queue>
using namespace llvm;
using namespace IGC::Debug;
namespace IGC {
#define PASS_FLAG "igc-address-arith-sinking"
#define PASS_DESCRIPTION "IGC Address Arithmetic Sinking"
#define PASS_CFG_ONLY false
#define PASS_ANALYSIS false
IGC_INITIALIZE_PASS_BEGIN(AddressArithmeticSinking, PASS_FLAG, PASS_DESCRIPTION, PASS_CFG_ONLY, PASS_ANALYSIS)
IGC_INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
IGC_INITIALIZE_PASS_DEPENDENCY(PostDominatorTreeWrapperPass)
IGC_INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
IGC_INITIALIZE_PASS_END(AddressArithmeticSinking, PASS_FLAG, PASS_DESCRIPTION, PASS_CFG_ONLY, PASS_ANALYSIS)
// This pass aimed to reduce register pressure by moving address arithmetic closer to load/store
AddressArithmeticSinking::AddressArithmeticSinking(unsigned SinkingDepth) :
FunctionPass(ID), m_SinkingDepth(SinkingDepth)
{
initializeAddressArithmeticSinkingPass(*PassRegistry::getPassRegistry());
}
bool AddressArithmeticSinking::runOnFunction(Function& F)
{
DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
bool changed = false;
for (po_iterator<DomTreeNode*> domIter = po_begin(DT->getRootNode()),
domEnd = po_end(DT->getRootNode()); domIter != domEnd; ++domIter) {
BasicBlock* BB = domIter->getBlock();
changed |= ProcessBB(BB);
}
return changed;
}
static bool isAddressArithmetic(Instruction* I)
{
if (isa<GetElementPtrInst>(I) ||
isa<ExtractElementInst>(I) ||
isa<InsertElementInst>(I) ||
isa<InsertValueInst>(I) ||
(isa<UnaryInstruction>(I) && !isa<LoadInst>(I)) ||
isa<BinaryOperator>(I))
return true;
return false;
}
static void findArithmeticForPtr(Instruction* I, unsigned depth, SmallPtrSetImpl<Instruction*>& AddressArithmetic)
{
std::queue<Instruction*> IQ;
IQ.push(I);
while (depth && !IQ.empty()) {
Instruction* CurI = IQ.front();
IQ.pop();
for (Use &U : CurI->operands()) {
auto UseI = dyn_cast<Instruction>(U.get());
if(UseI == nullptr)
continue;
if (!isAddressArithmetic(UseI))
continue;
if (UseI->getParent() != I->getParent())
continue;
AddressArithmetic.insert(UseI);
IQ.push(UseI);
}
depth--;
}
}
bool AddressArithmeticSinking::ProcessBB(BasicBlock* BB)
{
bool changed = false;
SmallPtrSet<Instruction*, 16> AddressArithmetic;
for (auto II = BB->rbegin(), IE = BB->rend(); II != IE; ) {
Instruction* I = &*II++;
if (isa<IntToPtrInst>(I)) {
findArithmeticForPtr(I, m_SinkingDepth, AddressArithmetic);
changed |= sink(I);
continue;
}
if (AddressArithmetic.find(I) != AddressArithmetic.end())
changed |= sink(I);
}
return changed;
}
BasicBlock* AddressArithmeticSinking::FindSinkTarget(Instruction* I)
{
BasicBlock* tgtBB = nullptr;
for (Value::user_iterator UI = I->user_begin(), UE = I->user_end(); UI != UE; ++UI) {
Instruction* useInst = cast<Instruction>(*UI);
BasicBlock* useBlock = useInst->getParent();
if (PHINode * PN = dyn_cast<PHINode>(useInst)) {
Use& U = UI.getUse();
unsigned num = PHINode::getIncomingValueNumForOperand(U.getOperandNo());
useBlock = PN->getIncomingBlock(num);
}
else {
if (useBlock == I->getParent())
return nullptr;
}
if (tgtBB != nullptr) {
tgtBB = DT->findNearestCommonDominator(tgtBB, useBlock);
if (tgtBB == nullptr)
return nullptr;
}
else {
tgtBB = useBlock;
}
}
return tgtBB;
}
static Instruction* findFirstUse(BasicBlock* BB, const SmallPtrSetImpl<Instruction*>& usesInBB)
{
for (auto II = BB->begin(), IE = BB->end(); II != IE; ++II) {
Instruction* Use = &(*II);
if (usesInBB.count(Use))
return Use;
}
return nullptr;
}
bool AddressArithmeticSinking::sink(Instruction* I)
{
BasicBlock* tgtBB = FindSinkTarget(I);
if (tgtBB == nullptr)
return false;
SmallPtrSet<Instruction*, 8> usesInBB;
for (Value::user_iterator UI = I->user_begin(), UE = I->user_end(); UI != UE; ++UI) {
Instruction* useInst = cast<Instruction>(*UI);
BasicBlock* useBlock = useInst->getParent();
if (useBlock == tgtBB)
usesInBB.insert(useInst);
}
if (usesInBB.empty())
I->moveBefore(tgtBB->getTerminator());
else if (usesInBB.size() == 1) {
Instruction* use = *(usesInBB.begin());
if (!isa<PHINode>(use))
I->moveBefore(use);
}
else {
Instruction* firstUse = findFirstUse(tgtBB, usesInBB);
IGC_ASSERT(firstUse);
if (!isa<PHINode>(firstUse))
I->moveBefore(firstUse);
}
return true;
}
char AddressArithmeticSinking::ID = 0;
} // namespace IGC
|
