diff options
| author | Damien George <damien@micropython.org> | 2022-05-19 15:05:32 +1000 |
|---|---|---|
| committer | Damien George <damien@micropython.org> | 2022-05-19 17:31:56 +1000 |
| commit | 56f2d3c2e5b9a9c0f0470f3850216c3191a59b67 (patch) | |
| tree | c0d8fd7ee1a5ff8822e97170555cf56ce2c069ba /py/asmthumb.c | |
| parent | c70f96f1c57456031c5b3fc9bd89a564106e345b (diff) | |
py/asmthumb: Fix PC relative load by sign extending the constant.
PC relative offsets can be negative, in which case the movw result must be
sign extended.
Signed-off-by: Damien George <damien@micropython.org>
Diffstat (limited to 'py/asmthumb.c')
| -rw-r--r-- | py/asmthumb.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/py/asmthumb.c b/py/asmthumb.c index db4520ce1..04fb82330 100644 --- a/py/asmthumb.c +++ b/py/asmthumb.c @@ -430,8 +430,9 @@ void asm_thumb_mov_reg_pcrel(asm_thumb_t *as, uint rlo_dest, uint label) { mp_int_t rel = dest - as->base.code_offset; rel |= 1; // to stay in Thumb state when jumping to this address #if MICROPY_EMIT_THUMB_ARMV7M - rel -= 4 + 4; // adjust for mov_reg_i16 and then PC+4 prefetch of add_reg_reg + rel -= 6 + 4; // adjust for mov_reg_i16, sxth_rlo_rlo and then PC+4 prefetch of add_reg_reg asm_thumb_mov_reg_i16(as, ASM_THUMB_OP_MOVW, rlo_dest, rel); // 4 bytes + asm_thumb_sxth_rlo_rlo(as, rlo_dest, rlo_dest); // 2 bytes #else rel -= 8 + 4; // adjust for four instructions and then PC+4 prefetch of add_reg_reg // 6 bytes |