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
|
/*
* Copyright 2024 WebAssembly Community Group participants
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
//
// Lowers a module with a 64-bit table to one with a 32-bit table.
//
// This pass can be deleted once table64 is implemented in Wasm engines:
// https://github.com/WebAssembly/memory64/issues/51
//
#include "ir/bits.h"
#include "ir/import-utils.h"
#include "pass.h"
#include "wasm-builder.h"
#include "wasm.h"
namespace wasm {
static Name TABLE_BASE("__table_base");
static Name TABLE_BASE32("__table_base32");
struct Table64Lowering : public WalkerPass<PostWalker<Table64Lowering>> {
void wrapAddress64(Expression*& ptr, Name tableName) {
if (ptr->type == Type::unreachable) {
return;
}
auto& module = *getModule();
auto* table = module.getTable(tableName);
if (table->is64()) {
assert(ptr->type == Type::i64);
ptr = Builder(module).makeUnary(UnaryOp::WrapInt64, ptr);
}
}
void extendAddress64(Expression*& ptr, Name tableName) {
if (ptr->type == Type::unreachable) {
return;
}
auto& module = *getModule();
auto* table = module.getTable(tableName);
if (table->is64()) {
assert(ptr->type == Type::i64);
ptr->type = Type::i32;
ptr = Builder(module).makeUnary(UnaryOp::ExtendUInt32, ptr);
}
}
void visitTableSize(TableSize* curr) {
auto& module = *getModule();
auto* table = module.getTable(curr->table);
if (table->is64()) {
auto* size = static_cast<Expression*>(curr);
extendAddress64(size, curr->table);
replaceCurrent(size);
}
}
void visitTableGrow(TableGrow* curr) {
auto& module = *getModule();
auto* table = module.getTable(curr->table);
if (table->is64()) {
wrapAddress64(curr->delta, curr->table);
auto* size = static_cast<Expression*>(curr);
extendAddress64(size, curr->table);
replaceCurrent(size);
}
}
void visitTableFill(TableFill* curr) {
wrapAddress64(curr->dest, curr->table);
wrapAddress64(curr->size, curr->table);
}
void visitTableCopy(TableCopy* curr) {
wrapAddress64(curr->dest, curr->destTable);
wrapAddress64(curr->source, curr->sourceTable);
wrapAddress64(curr->size, curr->destTable);
}
void visitTableInit(TableInit* curr) {
wrapAddress64(curr->dest, curr->table);
}
void visitCallIndirect(CallIndirect* curr) {
wrapAddress64(curr->target, curr->table);
}
void visitElementSegment(ElementSegment* segment) {
auto& module = *getModule();
// Passive segments don't have any offset to update.
if (segment->table.isNull() || !module.getTable(segment->table)->is64()) {
return;
}
if (auto* c = segment->offset->dynCast<Const>()) {
c->value = Literal(static_cast<uint32_t>(c->value.geti64()));
c->type = Type::i32;
} else if (auto* get = segment->offset->dynCast<GlobalGet>()) {
auto* g = module.getGlobal(get->name);
if (g->imported() && g->base == TABLE_BASE) {
ImportInfo info(module);
auto* memoryBase32 = info.getImportedGlobal(g->module, TABLE_BASE32);
if (!memoryBase32) {
Builder builder(module);
memoryBase32 = builder
.makeGlobal(TABLE_BASE32,
Type::i32,
builder.makeConst(int32_t(0)),
Builder::Immutable)
.release();
memoryBase32->module = g->module;
memoryBase32->base = TABLE_BASE32;
module.addGlobal(memoryBase32);
}
// Use this alternative import when initializing the segment.
assert(memoryBase32);
get->type = Type::i32;
get->name = memoryBase32->name;
}
} else {
WASM_UNREACHABLE("unexpected elem offset");
}
}
void run(Module* module) override {
Super::run(module);
// Don't modify the tables themselves until after the traversal since we
// that would require tables to be the last thing that get visited, and
// we don't want to depend on that specific ordering.
for (auto& table : module->tables) {
if (table->is64()) {
table->addressType = Type::i32;
}
}
}
};
Pass* createTable64LoweringPass() { return new Table64Lowering(); }
} // namespace wasm
|
