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
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
|
import "compiler/ast.cup"
import "std/file.cup"
let gen_out_file: File*;
let gen_label_counter = 0;
fn emit_asm4(msg1: char*, msg2: char*, msg3: char*, msg4: char*) {
fwrite(gen_out_file, msg1, strlen(msg1));
fwrite(gen_out_file, msg2, strlen(msg2));
fwrite(gen_out_file, msg3, strlen(msg3));
fwrite(gen_out_file, msg4, strlen(msg4));
}
fn emit_asm3(msg1: char*, msg2: char*, msg3: char*) {
fwrite(gen_out_file, msg1, strlen(msg1));
fwrite(gen_out_file, msg2, strlen(msg2));
fwrite(gen_out_file, msg3, strlen(msg3));
}
fn emit_asm2(msg1: char*, msg2: char*) {
fwrite(gen_out_file, msg1, strlen(msg1));
fwrite(gen_out_file, msg2, strlen(msg2));
}
fn emit_asm(msg: char*) {
fwrite(gen_out_file, msg, strlen(msg));
}
fn emit_num(num: int) {
fputu(gen_out_file, num);
}
fn generate_syscall(num: int) {
emit_asm(" mov rax, "); emit_num(num); emit_asm("\n");
emit_asm(" syscall\n");
}
fn generate_lvalue_into_rax(node: Node*) {
if (node.typ == AST_LOCAL_VAR) {
let offset = node.d.variable.offset;
emit_asm(" mov rax, rbp\n");
emit_asm(" sub rax, "); emit_num(offset); emit_asm("\n");
} else {
die2("Unsupported type in generate_lvalue_into_rax: ", node_type_to_string(node.typ));
}
}
fn generate_expr_into_rax(node: Node*) {
if (node.typ == AST_LITERAL) {
if (node.etyp.typ == TYPE_INT) {
emit_asm(" mov rax, "); emit_num(node.d.literal.as_int); emit_asm("\n");
} else {
die("Unsupported literal type in generate_expr_into_rax");
}
} else if (node.typ == AST_CONDITIONAL) {
let label = ++gen_label_counter;
generate_expr_into_rax(node.d.conditional.cond);
emit_asm(" cmp rax, 0\n");
emit_asm(" je .cond_els"); emit_num(label); emit_asm("\n");
generate_expr_into_rax(node.d.conditional.then);
emit_asm(" jmp .cond"); emit_num(label); emit_asm("\n");
emit_asm(".cond_els"); emit_num(label); emit_asm(":\n");
generate_expr_into_rax(node.d.conditional.els);
emit_asm(".cond"); emit_num(label); emit_asm(":\n");
} else if (node.typ == AST_PLUS) {
generate_expr_into_rax(node.d.binary.rhs);
emit_asm(" push rax\n");
generate_expr_into_rax(node.d.binary.lhs);
emit_asm(" pop rbx\n");
emit_asm(" add rax, rbx\n");
} else if (node.typ == AST_MINUS) {
generate_expr_into_rax(node.d.binary.rhs);
emit_asm(" push rax\n");
generate_expr_into_rax(node.d.binary.lhs);
emit_asm(" pop rbx\n");
emit_asm(" sub rax, rbx\n");
} else if (node.typ == AST_DIV) {
generate_expr_into_rax(node.d.binary.rhs);
emit_asm(" push rax\n");
generate_expr_into_rax(node.d.binary.lhs);
emit_asm(" pop rbx\n");
emit_asm(" cqo\n");
emit_asm(" idiv rbx\n");
} else if (node.typ == AST_MOD) {
generate_expr_into_rax(node.d.binary.rhs);
emit_asm(" push rax\n");
generate_expr_into_rax(node.d.binary.lhs);
emit_asm(" pop rbx\n");
emit_asm(" cqo\n");
emit_asm(" idiv rbx\n");
emit_asm(" mov rax, rdx\n");
} else if (node.typ == AST_MUL) {
generate_expr_into_rax(node.d.binary.rhs);
emit_asm(" push rax\n");
generate_expr_into_rax(node.d.binary.lhs);
emit_asm(" pop rbx\n");
emit_asm(" imul rbx\n");
} else if (node.typ == AST_EQ) {
generate_expr_into_rax(node.d.binary.rhs);
emit_asm(" push rax\n");
generate_expr_into_rax(node.d.binary.lhs);
emit_asm(" pop rbx\n");
emit_asm(" cmp rax, rbx\n");
emit_asm(" sete al\n");
emit_asm(" movzx rax, al\n");
} else if (node.typ == AST_NEQ) {
generate_expr_into_rax(node.d.binary.rhs);
emit_asm(" push rax\n");
generate_expr_into_rax(node.d.binary.lhs);
emit_asm(" pop rbx\n");
emit_asm(" cmp rax, rbx\n");
emit_asm(" setne al\n");
emit_asm(" movzx rax, al\n");
} else if (node.typ == AST_LT) {
generate_expr_into_rax(node.d.binary.rhs);
emit_asm(" push rax\n");
generate_expr_into_rax(node.d.binary.lhs);
emit_asm(" pop rbx\n");
emit_asm(" cmp rax, rbx\n");
emit_asm(" setl al\n");
emit_asm(" movzx rax, al\n");
} else if (node.typ == AST_LEQ) {
generate_expr_into_rax(node.d.binary.rhs);
emit_asm(" push rax\n");
generate_expr_into_rax(node.d.binary.lhs);
emit_asm(" pop rbx\n");
emit_asm(" cmp rax, rbx\n");
emit_asm(" setle al\n");
emit_asm(" movzx rax, al\n");
} else if (node.typ == AST_GT) {
generate_expr_into_rax(node.d.binary.rhs);
emit_asm(" push rax\n");
generate_expr_into_rax(node.d.binary.lhs);
emit_asm(" pop rbx\n");
emit_asm(" cmp rax, rbx\n");
emit_asm(" setg al\n");
emit_asm(" movzx rax, al\n");
} else if (node.typ == AST_GEQ) {
generate_expr_into_rax(node.d.binary.rhs);
emit_asm(" push rax\n");
generate_expr_into_rax(node.d.binary.lhs);
emit_asm(" pop rbx\n");
emit_asm(" cmp rax, rbx\n");
emit_asm(" setge al\n");
emit_asm(" movzx rax, al\n");
} else if (is_lvalue(node.typ)) {
generate_lvalue_into_rax(node);
emit_asm(" mov rax, [rax]\n");
} else if (node.typ == AST_ASSIGN) {
putsln("...");
generate_lvalue_into_rax(node.d.assign.lhs);
emit_asm(" push rax\n");
generate_expr_into_rax(node.d.assign.rhs);
emit_asm(" pop rbx\n");
emit_asm(" mov [rbx], rax\n");
} else {
die2("Unsupported node type in generate_expr_into_rax: ", node_type_to_string(node.typ));
}
}
fn generate_block(node: Node*);
fn generate_statement(node: Node*) {
if (node.typ == AST_RETURN) {
generate_expr_into_rax(node.d.unary);
emit_asm(" mov rsp, rbp\n");
emit_asm(" pop rbp\n");
emit_asm(" ret\n");
} else if (node.typ == AST_VARDECL) {
if (node.d.var_decl.init) {
generate_expr_into_rax(node.d.var_decl.init);
let offset = node.d.var_decl.var.offset;
emit_asm(" mov [rbp-"); emit_num(offset); emit_asm("], rax\n");
}
} else if (node.typ == AST_BLOCK) {
generate_block(node);
} else if (node.typ == AST_IF) {
let label = ++gen_label_counter;
generate_expr_into_rax(node.d.conditional.cond);
emit_asm(" cmp rax, 0\n");
emit_asm(" je .els"); emit_num(label); emit_asm("\n");
generate_block(node.d.conditional.then);
emit_asm(" jmp .if"); emit_num(label); emit_asm("\n");
emit_asm(".els"); emit_num(label); emit_asm(":\n");
if (node.d.conditional.els)
generate_block(node.d.conditional.els);
emit_asm(".if"); emit_num(label); emit_asm(":\n");
} else {
// Default to a simple expression statement
generate_expr_into_rax(node);
}
}
fn generate_block(node: Node*) {
let n = node.d.block.children.size;
for (let i = 0; i < n; ++i) {
generate_statement(node.d.block.children.data[i]);
}
}
fn generate_function(node: Node*) {
emit_asm3("global func_", node.d.func.name, "\n");
emit_asm3("func_", node.d.func.name, ":\n");
emit_asm(" push rbp\n");
emit_asm(" mov rbp, rsp\n");
emit_asm(" sub rsp, "); emit_num(node.d.func.max_locals_size); emit_asm("\n");
generate_block(node.d.func.body);
emit_asm(" mov rsp, rbp\n");
emit_asm(" pop rbp\n");
emit_asm(" ret\n");
}
fn generate_program(ast: Node*, file: File*) {
gen_out_file = file;
let n = ast.d.block.children.size;
for (let i = 0; i < n; ++i) {
let node: Node* = ast.d.block.children.data[i];
if (node.typ == AST_FUNC) {
generate_function(node);
} else {
die("Unknown node type in generate_program");
}
}
if (OS_IS_MACOS) {
emit_asm("global _main\n");
emit_asm("_main:\n");
// Push argv
emit_asm(" mov rax, rsi\n");
emit_asm(" push rax\n");
// Push argc
emit_asm(" mov rax, rdi\n");
emit_asm(" push rax\n");
} else {
emit_asm("global _start\n");
emit_asm("_start:\n");
emit_asm(" mov rbp, rsp\n");
// // Push argv
emit_asm(" mov rax, rbp\n");
emit_asm(" add rax, 8\n");
emit_asm(" push rax\n");
// Push argc
emit_asm(" mov rax, [rbp]\n");
emit_asm(" push rax\n");
}
emit_asm(" call func_main\n");
emit_asm(" mov rdi, rax\n");
generate_syscall(SYS_exit);
}
|