Your problem is the wrong using of pointer arithmetics
+delta moves pointer not to delta bytes but to delta units, each unit size depends on the pointre type
So you can use high_bits = low_bits +1;
Or if you prefer your approach - cast &x to unsinged char before adding sizeof(int)
All problems in computer science can be solved by another level of indirection,
except for the problem of too many layers of indirection.
– David J. Wheeler
Or something like:
--Code:unsigned int *high_bits = ((unsigned int *)(&x)) + 1;
Mats
Compilers can produce warnings - make the compiler programmers happy: Use them!
Please don't PM me for help - and no, I don't do help over instant messengers.
This is undefined behaviour, as is the original poster's code. You may only use a character pointer. If you have the ISO/IEC 9899:1999 standard handy, see section 6.3.2.3 paragraph 7.Originally Posted by matsp
The following, for example, is well defined:
Code:void split(double x) { unsigned char *y = (unsigned char *)&x; int i; for (i = 0; i < sizeof(double); i++) printf("%02x", y[i]); puts(""); }
Correct, but it's only undefined if a double is not aligned to the same as (or a multiple of) "unsigned int", and whilst I'm sure there are machines where such a construction may be the case (someone implementing for example 56 or 80 bit "double" would fall into this category), it is not a common occurrence.
Does anyone here actually know of (and are actually using, as opposed to knowing of the existence) a machine where this is the case?
--
Mats
Compilers can produce warnings - make the compiler programmers happy: Use them!
Please don't PM me for help - and no, I don't do help over instant messengers.
