Minor changes

[libfirm] / ir / tv / strcalc.c

diff --git a/ir/tv/strcalc.c b/ir/tv/strcalc.c
index fefa802..10bf885 100644 (file)
--- a/ir/tv/strcalc.c
+++ b/ir/tv/strcalc.c
@@ -1268,13 +1268,17 @@ unsigned char sc_sub_bits(const void *value, int len, unsigned byte_ofs) {
        unsigned char res;
 
        /* the current scheme uses one byte to store a nibble */
-       if (nibble_ofs >= len)
+       if (4 * nibble_ofs >= len)
                return 0;
 
        res = _val(val[nibble_ofs]);
-       if (len > nibble_ofs + 1)
+       if (len > 4 * (nibble_ofs + 1))
                res |= _val(val[nibble_ofs + 1]) << 4;
 
+       /* kick bits outsize */
+       if (len < 8*byte_ofs) {
+               res &= 0xFF >> (8*byte_ofs - len);
+       }
        return res;
 }