void asm_xtensa_exit(asm_xtensa_t *as) {
// restore registers
for (int i = NUM_REGS_SAVED - 1; i >= 1; --i) {
asm_xtensa_op_l32i_n(as, ASM_XTENSA_REG_A11 + i, ASM_XTENSA_REG_A1, i);
}
asm_xtensa_op_l32i_n(as, ASM_XTENSA_REG_A0, ASM_XTENSA_REG_A1, 0);
// restore stack-pointer and return
if (SIGNED_FIT8(as->stack_adjust)) {
asm_xtensa_op_addi(as, ASM_XTENSA_REG_A1, ASM_XTENSA_REG_A1, as->stack_adjust);
} else {
asm_xtensa_op_movi(as, ASM_XTENSA_REG_A9, as->stack_adjust);
asm_xtensa_op_add_n(as, ASM_XTENSA_REG_A1, ASM_XTENSA_REG_A1, ASM_XTENSA_REG_A9);
}
asm_xtensa_op_ret_n(as);
}
STATIC void emit_inline_xtensa_op(emit_inline_asm_t *emit, qstr op, mp_uint_t n_args, mp_parse_node_t *pn_args) {
size_t op_len;
const char *op_str = (const char*)qstr_data(op, &op_len);
if (n_args == 0) {
if (op == MP_QSTR_ret_n) {
asm_xtensa_op_ret_n(&emit->as);
} else {
goto unknown_op;
}
} else if (n_args == 1) {
if (op == MP_QSTR_callx0) {
uint r0 = get_arg_reg(emit, op_str, pn_args[0]);
asm_xtensa_op_callx0(&emit->as, r0);
} else if (op == MP_QSTR_j) {
int label = get_arg_label(emit, op_str, pn_args[0]);
asm_xtensa_j_label(&emit->as, label);
} else if (op == MP_QSTR_jx) {
uint r0 = get_arg_reg(emit, op_str, pn_args[0]);
asm_xtensa_op_jx(&emit->as, r0);
} else {
goto unknown_op;
}
} else if (n_args == 2) {
uint r0 = get_arg_reg(emit, op_str, pn_args[0]);
if (op == MP_QSTR_beqz) {
int label = get_arg_label(emit, op_str, pn_args[1]);
asm_xtensa_bccz_reg_label(&emit->as, ASM_XTENSA_CCZ_EQ, r0, label);
} else if (op == MP_QSTR_bnez) {
int label = get_arg_label(emit, op_str, pn_args[1]);
asm_xtensa_bccz_reg_label(&emit->as, ASM_XTENSA_CCZ_NE, r0, label);
} else if (op == MP_QSTR_mov || op == MP_QSTR_mov_n) {
// we emit mov.n for both "mov" and "mov_n" opcodes
uint r1 = get_arg_reg(emit, op_str, pn_args[1]);
asm_xtensa_op_mov_n(&emit->as, r0, r1);
} else if (op == MP_QSTR_movi) {
// for convenience we emit l32r if the integer doesn't fit in movi
uint32_t imm = get_arg_i(emit, op_str, pn_args[1], 0, 0);
asm_xtensa_mov_reg_i32(&emit->as, r0, imm);
} else {
goto unknown_op;
}
} else if (n_args == 3) {
// search table for 3 arg instructions
for (uint i = 0; i < MP_ARRAY_SIZE(opcode_table_3arg); i++) {
const opcode_table_3arg_t *o = &opcode_table_3arg[i];
if (op == o->name) {
uint r0 = get_arg_reg(emit, op_str, pn_args[0]);
uint r1 = get_arg_reg(emit, op_str, pn_args[1]);
if (o->type == RRR) {
uint r2 = get_arg_reg(emit, op_str, pn_args[2]);
asm_xtensa_op24(&emit->as, ASM_XTENSA_ENCODE_RRR(0, o->a0, o->a1, r0, r1, r2));
} else if (o->type == RRI8_B) {
int label = get_arg_label(emit, op_str, pn_args[2]);
asm_xtensa_bcc_reg_reg_label(&emit->as, o->a0, r0, r1, label);
} else {
int shift, min, max;
if ((o->type & 0xf0) == 0) {
shift = 0;
min = -128;
max = 127;
} else {
shift = (o->type & 0xf0) >> 5;
min = 0;
max = 0xff << shift;
}
uint32_t imm = get_arg_i(emit, op_str, pn_args[2], min, max);
asm_xtensa_op24(&emit->as, ASM_XTENSA_ENCODE_RRI8(o->a0, o->a1, r1, r0, (imm >> shift) & 0xff));
}
return;
}
}
goto unknown_op;
} else {
