void emit_jle( assembler_buffer_t * buf, label_t * lab) {
emit_jcc(buf, lab, LE);
}
void emit_jne( assembler_buffer_t * buf, label_t * lab) {
emit_jcc(buf, lab, NEQ);
}
static void x86_emit_inst(Inst* inst, int* pc2addr, int rodata_addr) {
switch (inst->op) {
case MOV:
emit_mov(inst->dst.reg, &inst->src);
break;
case ADD:
if (inst->src.type == REG) {
emit_1(0x01);
emit_reg2(inst->dst.reg, inst->src.reg);
} else {
emit_2(0x81, 0xc0 + REGNO[inst->dst.reg]);
emit_le(inst->src.imm);
}
emit_2(0x81, 0xe0 + REGNO[inst->dst.reg]);
emit_le(0xffffff);
break;
case SUB:
if (inst->src.type == REG) {
emit_1(0x29);
emit_reg2(inst->dst.reg, inst->src.reg);
} else {
emit_2(0x81, 0xe8 + REGNO[inst->dst.reg]);
emit_le(inst->src.imm);
}
emit_2(0x81, 0xe0 + REGNO[inst->dst.reg]);
emit_le(0xffffff);
break;
case LOAD:
emit_1(0x8b);
goto store_load_common;
case STORE:
emit_1(0x89);
store_load_common:
if (inst->src.type == REG) {
emit_2(4 + (REGNO[inst->dst.reg] * 8),
0x86 + (REGNO[inst->src.reg] * 8));
} else {
emit_1(0x86 + (REGNO[inst->dst.reg] * 8));
emit_le(inst->src.imm * 4);
}
break;
case PUTC:
// push EDI
emit_1(0x57);
emit_mov(EDI, &inst->src);
// push EAX, ECX, EDX, EBX, EDI
emit_5(0x50, 0x51, 0x52, 0x53, 0x57);
emit_mov_imm(B, 1); // stdout
emit_mov_reg(C, ESP);
emit_mov_imm(D, 1);
emit_mov_imm(A, 4); // write
emit_int80();
// pop EDI, EBX, EDX, ECX, EAX
emit_5(0x5f, 0x5b, 0x5a, 0x59, 0x58);
// pop EDI
emit_1(0x5f);
break;
case GETC:
// push EDI
emit_1(0x57);
// push EAX, ECX, EDX, EBX
emit_4(0x50, 0x51, 0x52, 0x53);
// push 0
emit_2(0x6a, 0x00);
emit_mov_imm(B, 0); // stdin
emit_mov_reg(C, ESP);
emit_mov_imm(D, 1);
emit_mov_imm(A, 3); // read
emit_int80();
// pop EDI
emit_1(0x5f);
emit_mov_imm(B, 0);
// cmp EAX, 1
emit_3(0x83, 0xf8, 0x01);
// cmovnz EDI, EBX
emit_3(0x0f, 0x45, 0xfb);
// pop EBX, EDX, ECX, EAX
emit_4(0x5b, 0x5a, 0x59, 0x58);
emit_mov_reg(inst->dst.reg, EDI);
// pop EDI
emit_1(0x5f);
break;
case EXIT:
emit_mov_imm(B, 0);
emit_mov_imm(A, 1); // exit
emit_int80();
break;
case DUMP:
break;
case EQ:
emit_setcc(inst, 0x94);
break;
case NE:
emit_setcc(inst, 0x95);
break;
case LT:
emit_setcc(inst, 0x9c);
break;
case GT:
emit_setcc(inst, 0x9f);
break;
case LE:
emit_setcc(inst, 0x9e);
break;
case GE:
emit_setcc(inst, 0x9d);
break;
case JEQ:
emit_jcc(inst, 0x75, pc2addr, rodata_addr);
break;
case JNE:
emit_jcc(inst, 0x74, pc2addr, rodata_addr);
break;
case JLT:
emit_jcc(inst, 0x7d, pc2addr, rodata_addr);
break;
case JGT:
emit_jcc(inst, 0x7e, pc2addr, rodata_addr);
break;
case JLE:
emit_jcc(inst, 0x7f, pc2addr, rodata_addr);
break;
case JGE:
emit_jcc(inst, 0x7c, pc2addr, rodata_addr);
break;
case JMP:
emit_jcc(inst, 0, pc2addr, rodata_addr);
break;
default:
error("oops");
}
}
