diff options
Diffstat (limited to 'py/asmxtensa.c')
| -rw-r--r-- | py/asmxtensa.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/py/asmxtensa.c b/py/asmxtensa.c index bec7f36db..d44c310ee 100644 --- a/py/asmxtensa.c +++ b/py/asmxtensa.c @@ -182,4 +182,26 @@ void asm_xtensa_mov_reg_local_addr(asm_xtensa_t *as, uint reg_dest, int local_nu asm_xtensa_op_addi(as, reg_dest, reg_dest, (4 + local_num) * WORD_SIZE); } +void asm_xtensa_mov_reg_pcrel(asm_xtensa_t *as, uint reg_dest, uint label) { + // Get relative offset from PC + uint32_t dest = get_label_dest(as, label); + int32_t rel = dest - as->base.code_offset; + rel -= 3 + 3; // account for 3 bytes of movi instruction, 3 bytes call0 adjustment + asm_xtensa_op_movi(as, reg_dest, rel); // imm has 12-bit range + + // Use call0 to get PC+3 into a0 + // call0 destination must be aligned on 4 bytes: + // - code_offset&3=0: off=0, pad=1 + // - code_offset&3=1: off=0, pad=0 + // - code_offset&3=2: off=1, pad=3 + // - code_offset&3=3: off=1, pad=2 + uint32_t off = as->base.code_offset >> 1 & 1; + uint32_t pad = (5 - as->base.code_offset) & 3; + asm_xtensa_op_call0(as, off); + mp_asm_base_get_cur_to_write_bytes(&as->base, pad); + + // Add PC to relative offset + asm_xtensa_op_add(as, reg_dest, reg_dest, ASM_XTENSA_REG_A0); +} + #endif // MICROPY_EMIT_XTENSA || MICROPY_EMIT_INLINE_XTENSA |