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
|
//===---- CGLoopInfo.cpp - LLVM CodeGen for loop metadata -*- C++ -*-------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "CGLoopInfo.h"
#include "clang/AST/Attr.h"
#include "clang/Sema/LoopHint.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Metadata.h"
using namespace clang::CodeGen;
using namespace llvm;
static MDNode *createMetadata(LLVMContext &Ctx, const LoopAttributes &Attrs) {
if (!Attrs.IsParallel && Attrs.VectorizerWidth == 0 &&
Attrs.VectorizerUnroll == 0 &&
Attrs.VectorizerEnable == LoopAttributes::VecUnspecified)
return nullptr;
SmallVector<Metadata *, 4> Args;
// Reserve operand 0 for loop id self reference.
auto TempNode = MDNode::getTemporary(Ctx, None);
Args.push_back(TempNode.get());
// Setting vectorizer.width
if (Attrs.VectorizerWidth > 0) {
Metadata *Vals[] = {MDString::get(Ctx, "llvm.loop.vectorize.width"),
ConstantAsMetadata::get(ConstantInt::get(
Type::getInt32Ty(Ctx), Attrs.VectorizerWidth))};
Args.push_back(MDNode::get(Ctx, Vals));
}
// Setting vectorizer.unroll
if (Attrs.VectorizerUnroll > 0) {
Metadata *Vals[] = {MDString::get(Ctx, "llvm.loop.interleave.count"),
ConstantAsMetadata::get(ConstantInt::get(
Type::getInt32Ty(Ctx), Attrs.VectorizerUnroll))};
Args.push_back(MDNode::get(Ctx, Vals));
}
// Setting vectorizer.enable
if (Attrs.VectorizerEnable != LoopAttributes::VecUnspecified) {
Metadata *Vals[] = {
MDString::get(Ctx, "llvm.loop.vectorize.enable"),
ConstantAsMetadata::get(ConstantInt::get(
Type::getInt1Ty(Ctx),
(Attrs.VectorizerEnable == LoopAttributes::VecEnable)))};
Args.push_back(MDNode::get(Ctx, Vals));
}
// Set the first operand to itself.
MDNode *LoopID = MDNode::get(Ctx, Args);
LoopID->replaceOperandWith(0, LoopID);
return LoopID;
}
LoopAttributes::LoopAttributes(bool IsParallel)
: IsParallel(IsParallel), VectorizerEnable(LoopAttributes::VecUnspecified),
VectorizerWidth(0), VectorizerUnroll(0) {}
void LoopAttributes::clear() {
IsParallel = false;
VectorizerWidth = 0;
VectorizerUnroll = 0;
VectorizerEnable = LoopAttributes::VecUnspecified;
}
LoopInfo::LoopInfo(BasicBlock *Header, const LoopAttributes &Attrs)
: LoopID(nullptr), Header(Header), Attrs(Attrs) {
LoopID = createMetadata(Header->getContext(), Attrs);
}
void LoopInfoStack::push(BasicBlock *Header,
ArrayRef<const clang::Attr *> Attrs) {
for (const auto *Attr : Attrs) {
const LoopHintAttr *LH = dyn_cast<LoopHintAttr>(Attr);
// Skip non loop hint attributes
if (!LH)
continue;
LoopHintAttr::OptionType Option = LH->getOption();
LoopHintAttr::LoopHintState State = LH->getState();
switch (Option) {
case LoopHintAttr::Vectorize:
case LoopHintAttr::Interleave:
if (State == LoopHintAttr::AssumeSafety) {
// Apply "llvm.mem.parallel_loop_access" metadata to load/stores.
setParallel(true);
}
break;
case LoopHintAttr::VectorizeWidth:
case LoopHintAttr::InterleaveCount:
case LoopHintAttr::Unroll:
case LoopHintAttr::UnrollCount:
// Nothing to do here for these loop hints.
break;
}
}
Active.push_back(LoopInfo(Header, StagedAttrs));
// Clear the attributes so nested loops do not inherit them.
StagedAttrs.clear();
}
void LoopInfoStack::pop() {
assert(!Active.empty() && "No active loops to pop");
Active.pop_back();
}
void LoopInfoStack::InsertHelper(Instruction *I) const {
if (!hasInfo())
return;
const LoopInfo &L = getInfo();
if (!L.getLoopID())
return;
if (TerminatorInst *TI = dyn_cast<TerminatorInst>(I)) {
for (unsigned i = 0, ie = TI->getNumSuccessors(); i < ie; ++i)
if (TI->getSuccessor(i) == L.getHeader()) {
TI->setMetadata("llvm.loop", L.getLoopID());
break;
}
return;
}
if (L.getAttributes().IsParallel && I->mayReadOrWriteMemory())
I->setMetadata("llvm.mem.parallel_loop_access", L.getLoopID());
}
|
