void asm_xtensa_entry(asm_xtensa_t *as, int num_locals) {
// jump over the constants
asm_xtensa_op_j(as, as->num_const * WORD_SIZE + 4 - 4);
mp_asm_base_get_cur_to_write_bytes(&as->base, 1); // padding/alignment byte
as->const_table = (uint32_t*)mp_asm_base_get_cur_to_write_bytes(&as->base, as->num_const * 4);
// adjust the stack-pointer to store a0, a12, a13, a14, a15 and locals, 16-byte aligned
as->stack_adjust = (((NUM_REGS_SAVED + num_locals) * WORD_SIZE) + 15) & ~15;
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_sub(as, ASM_XTENSA_REG_A1, ASM_XTENSA_REG_A1, ASM_XTENSA_REG_A9);
}
// save return value (a0) and callee-save registers (a12, a13, a14, a15)
asm_xtensa_op_s32i_n(as, ASM_XTENSA_REG_A0, ASM_XTENSA_REG_A1, 0);
for (int i = 1; i < NUM_REGS_SAVED; ++i) {
asm_xtensa_op_s32i_n(as, ASM_XTENSA_REG_A11 + i, ASM_XTENSA_REG_A1, i);
}
}
static inline byte *asm_thumb_get_cur_to_write_bytes(asm_thumb_t *as, int n) {
return mp_asm_base_get_cur_to_write_bytes(&as->base, n);
}
void asm_xtensa_op16(asm_xtensa_t *as, uint16_t op) {
uint8_t *c = mp_asm_base_get_cur_to_write_bytes(&as->base, 2);
if (c != NULL) {
c[0] = op;
c[1] = op >> 8;
}
