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
|
//===-- llvm/CodeGen/Spiller.cpp - Spiller -------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "spiller"
#include "Spiller.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/LiveRangeEdit.h"
#include "llvm/CodeGen/LiveStackAnalysis.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineLoopInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/VirtRegMap.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
using namespace llvm;
namespace {
enum SpillerName { trivial, inline_ };
}
static cl::opt<SpillerName>
spillerOpt("spiller",
cl::desc("Spiller to use: (default: standard)"),
cl::Prefix,
cl::values(clEnumVal(trivial, "trivial spiller"),
clEnumValN(inline_, "inline", "inline spiller"),
clEnumValEnd),
cl::init(trivial));
// Spiller virtual destructor implementation.
Spiller::~Spiller() {}
namespace {
/// Utility class for spillers.
class SpillerBase : public Spiller {
protected:
MachineFunctionPass *pass;
MachineFunction *mf;
VirtRegMap *vrm;
LiveIntervals *lis;
MachineFrameInfo *mfi;
MachineRegisterInfo *mri;
const TargetInstrInfo *tii;
const TargetRegisterInfo *tri;
/// Construct a spiller base.
SpillerBase(MachineFunctionPass &pass, MachineFunction &mf, VirtRegMap &vrm)
: pass(&pass), mf(&mf), vrm(&vrm)
{
lis = &pass.getAnalysis<LiveIntervals>();
mfi = mf.getFrameInfo();
mri = &mf.getRegInfo();
tii = mf.getTarget().getInstrInfo();
tri = mf.getTarget().getRegisterInfo();
}
/// Add spill ranges for every use/def of the live interval, inserting loads
/// immediately before each use, and stores after each def. No folding or
/// remat is attempted.
void trivialSpillEverywhere(LiveRangeEdit& LRE) {
LiveInterval* li = &LRE.getParent();
DEBUG(dbgs() << "Spilling everywhere " << *li << "\n");
assert(li->weight != HUGE_VALF &&
"Attempting to spill already spilled value.");
assert(!TargetRegisterInfo::isStackSlot(li->reg) &&
"Trying to spill a stack slot.");
DEBUG(dbgs() << "Trivial spill everywhere of reg" << li->reg << "\n");
const TargetRegisterClass *trc = mri->getRegClass(li->reg);
unsigned ss = vrm->assignVirt2StackSlot(li->reg);
// Iterate over reg uses/defs.
for (MachineRegisterInfo::reg_iterator
regItr = mri->reg_begin(li->reg); regItr != mri->reg_end();) {
// Grab the use/def instr.
MachineInstr *mi = &*regItr;
DEBUG(dbgs() << " Processing " << *mi);
// Step regItr to the next use/def instr.
do {
++regItr;
} while (regItr != mri->reg_end() && (&*regItr == mi));
// Collect uses & defs for this instr.
SmallVector<unsigned, 2> indices;
bool hasUse = false;
bool hasDef = false;
for (unsigned i = 0; i != mi->getNumOperands(); ++i) {
MachineOperand &op = mi->getOperand(i);
if (!op.isReg() || op.getReg() != li->reg)
continue;
hasUse |= mi->getOperand(i).isUse();
hasDef |= mi->getOperand(i).isDef();
indices.push_back(i);
}
// Create a new vreg & interval for this instr.
LiveInterval *newLI = &LRE.create();
newLI->weight = HUGE_VALF;
// Update the reg operands & kill flags.
for (unsigned i = 0; i < indices.size(); ++i) {
unsigned mopIdx = indices[i];
MachineOperand &mop = mi->getOperand(mopIdx);
mop.setReg(newLI->reg);
if (mop.isUse() && !mi->isRegTiedToDefOperand(mopIdx)) {
mop.setIsKill(true);
}
}
assert(hasUse || hasDef);
// Insert reload if necessary.
MachineBasicBlock::iterator miItr(mi);
if (hasUse) {
tii->loadRegFromStackSlot(*mi->getParent(), miItr, newLI->reg, ss, trc,
tri);
MachineInstr *loadInstr(prior(miItr));
SlotIndex loadIndex =
lis->InsertMachineInstrInMaps(loadInstr).getRegSlot();
SlotIndex endIndex = loadIndex.getNextIndex();
VNInfo *loadVNI =
newLI->getNextValue(loadIndex, lis->getVNInfoAllocator());
newLI->addRange(LiveRange(loadIndex, endIndex, loadVNI));
}
// Insert store if necessary.
if (hasDef) {
tii->storeRegToStackSlot(*mi->getParent(), llvm::next(miItr),newLI->reg,
true, ss, trc, tri);
MachineInstr *storeInstr(llvm::next(miItr));
SlotIndex storeIndex =
lis->InsertMachineInstrInMaps(storeInstr).getRegSlot();
SlotIndex beginIndex = storeIndex.getPrevIndex();
VNInfo *storeVNI =
newLI->getNextValue(beginIndex, lis->getVNInfoAllocator());
newLI->addRange(LiveRange(beginIndex, storeIndex, storeVNI));
}
}
}
};
} // end anonymous namespace
namespace {
/// Spills any live range using the spill-everywhere method with no attempt at
/// folding.
class TrivialSpiller : public SpillerBase {
public:
TrivialSpiller(MachineFunctionPass &pass, MachineFunction &mf,
VirtRegMap &vrm)
: SpillerBase(pass, mf, vrm) {}
void spill(LiveRangeEdit &LRE) {
// Ignore spillIs - we don't use it.
trivialSpillEverywhere(LRE);
}
};
} // end anonymous namespace
void Spiller::anchor() { }
llvm::Spiller* llvm::createSpiller(MachineFunctionPass &pass,
MachineFunction &mf,
VirtRegMap &vrm) {
switch (spillerOpt) {
case trivial: return new TrivialSpiller(pass, mf, vrm);
case inline_: return createInlineSpiller(pass, mf, vrm);
}
llvm_unreachable("Invalid spiller optimization");
}
|
