void assemble_binop(void) {
u16 pc = PC++;
int a, b;
int op = token;
/* alias for push x, pop x */
if (token == tPUSH) {
op = tSET;
a = 0x1a; // push
b = assemble_operand();
} else if (token == tPOP) {
op = tSET;
a = assemble_operand();
b = 0x18; // pop
} else if (token == tNOP) {
// SET 0,0
op = tSET;
a = 0x20;
b = 0x20;
} else {
a = assemble_operand();
expect(tCOMMA);
b = assemble_operand();
}
/* token to opcode */
op -= (tSET - 1);
image[pc] = op | (a << 4) | (b << 10);
}
void assemble_binop(int op) {
int pc = PC++;
int a, b;
a = assemble_operand();
expect(tCOMMA);
b = assemble_operand();
image[pc] = op | (a << 4) | (b << 10);
}
void assemble(const char *fn) {
u16 pc, n;
fin = fopen(fn, "r");
filename = fn;
linenumber = 0;
if (!fin) die("cannot read file");
for (;;) {
next();
switch (token) {
case tEOF:
goto done;
case tCOLON:
expect(tSTRING);
set_label(tstring, PC);
continue;
case tWORD:
assemble_imm_or_label();
continue;
case tSET: case tADD: case tSUB: case tMUL:
case tDIV: case tMOD: case tSHL: case tSHR:
case tAND: case tBOR: case tXOR: case tIFE:
case tIFN: case tIFG: case tIFB:
assemble_binop(token - tXXX);
continue;
case tJSR:
pc = PC++;
n = assemble_operand();
image[pc] = (n << 10) | 0x0010;
continue;
default:
die("unexpected: %s", tnames[token]);
}
}
done:
fclose(fin);
}
void assemble(const char *fn) {
u16 pc, n;
fin = fopen(fn, "r");
filename = fn;
linenumber = 0;
if (!fin) die("cannot read file");
for (;;) {
next();
again:
switch (token) {
case tEOF:
goto done;
case tSTRING:
expect(tCOLON);
set_label(tstring, PC);
continue;
case tCOLON:
expect(tSTRING);
set_label(tstring, PC);
continue;
case tWORD: case tDAT: case tDATA: case tDW:
assemble_imm_or_label();
goto again;
case tJMP: // alias for SET PC, ...
assemble_jump();
continue;
case tMOV: // alias for SET
token = tSET;
case tSET: case tADD: case tSUB: case tMUL:
case tDIV: case tMOD: case tSHL: case tSHR:
case tAND: case tBOR: case tXOR: case tIFE:
case tIFN: case tIFG: case tIFB:
case tPUSH: case tPOP: case tNOP:
assemble_binop();
continue;
case tJSR:
pc = PC++;
n = assemble_operand();
image[pc] = (n << 10) | (0x01 << 5);
continue;
case tINT:
pc = PC++;
n = assemble_operand();
image[pc] = (n << 10) | (0x08 << 5);
continue;
case tIAG:
pc = PC++;
n = assemble_operand();
image[pc] = (n << 10) | (0x09 << 5);
continue;
case tIAS:
pc = PC++;
n = assemble_operand();
image[pc] = (n << 10) | (0x0a << 5);
continue;
case tRFI:
pc = PC++;
n = assemble_operand();
image[pc] = (n << 10) | (0x0b << 5);
continue;
case tIAQ:
pc = PC++;
n = assemble_operand();
image[pc] = (n << 10) | (0x0c << 5);
continue;
case tHWN:
pc = PC++;
n = assemble_operand();
image[pc] = (n << 10) | (0x10 << 5);
continue;
case tHWQ:
pc = PC++;
n = assemble_operand();
image[pc] = (n << 10) | (0x11 << 5);
continue;
case tHWI:
pc = PC++;
n = assemble_operand();
image[pc] = (n << 10) | (0x12 << 5);
continue;
default:
die("unexpected: %s", tnames[token]);
}
}
done:
fclose(fin);
}
void assemble_jump(void) {
u16 pc = PC++;
image[pc] = 0x01c1 | (assemble_operand() << 10);
}