From a3c61004c2139091b24c81e22fa5afa9fa5f4979 Mon Sep 17 00:00:00 2001 From: Damien George Date: Mon, 12 Dec 2016 15:00:06 +1100 Subject: [PATCH] py/binary: Do zero extension when storing a value larger than word size. --- py/binary.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/py/binary.c b/py/binary.c index 699324bc6e..d22e0f342d 100644 --- a/py/binary.c +++ b/py/binary.c @@ -294,9 +294,10 @@ void mp_binary_set_val(char struct_type, char val_type, mp_obj_t val_in, byte ** #endif { val = mp_obj_get_int(val_in); - // sign extend if needed - if (BYTES_PER_WORD < 8 && size > sizeof(val) && is_signed(val_type) && (mp_int_t)val < 0) { - memset(p + sizeof(val), 0xff, size - sizeof(val)); + // zero/sign extend if needed + if (BYTES_PER_WORD < 8 && size > sizeof(val)) { + int c = (is_signed(val_type) && (mp_int_t)val < 0) ? 0xff : 0x00; + memset(p + sizeof(val), c, size - sizeof(val)); } } }