Mixing
How to add a bit sequence to the end of another sequence?
I have an bit sequence that is created using memset, I want to add the return of a function to the first sequence.
U16 *pointer_p = allocmem(); // 500 bytes
memset (&pointer_p, 0, size); // size = 497 bytes
U32 A = function(); //3 byte return value
how to append the return from the function at the end of data created, would the line of code below work?
pointer_p = (*pointer_p<<24)| A ;
Thank you!
c bit-manipulation bit binary-data
asked Nov 20 '18 at 16:41
Raaz444Raaz444
386
add a comment |
I have an bit sequence that is created using memset, I want to add the return of a function to the first sequence.
U16 *pointer_p = allocmem(); // 500 bytes
memset (&pointer_p, 0, size); // size = 497 bytes
U32 A = function(); //3 byte return value
how to append the return from the function at the end of data created, would the line of code below work?
pointer_p = (*pointer_p<<24)| A ;
Thank you!
c bit-manipulation bit binary-data
asked Nov 20 '18 at 16:41
Raaz444Raaz444
386
2
Should the data be inserted big- or little-endian? What is your processor, big- or little-endian?
– Fiddling Bits
Nov 20 '18 at 16:42
add a comment |
I have an bit sequence that is created using memset, I want to add the return of a function to the first sequence.
U16 *pointer_p = allocmem(); // 500 bytes
memset (&pointer_p, 0, size); // size = 497 bytes
U32 A = function(); //3 byte return value
how to append the return from the function at the end of data created, would the line of code below work?
pointer_p = (*pointer_p<<24)| A ;
Thank you!
c bit-manipulation bit binary-data
asked Nov 20 '18 at 16:41
Raaz444Raaz444
386
I have an bit sequence that is created using memset, I want to add the return of a function to the first sequence.
U16 *pointer_p = allocmem(); // 500 bytes
memset (&pointer_p, 0, size); // size = 497 bytes
U32 A = function(); //3 byte return value
how to append the return from the function at the end of data created, would the line of code below work?
pointer_p = (*pointer_p<<24)| A ;
Thank you!
c bit-manipulation bit binary-data
c bit-manipulation bit binary-data
asked Nov 20 '18 at 16:41
Raaz444Raaz444
386
asked Nov 20 '18 at 16:41
Raaz444Raaz444
386
asked Nov 20 '18 at 16:41
Raaz444Raaz444
386
asked Nov 20 '18 at 16:41
Raaz444Raaz444
386
asked Nov 20 '18 at 16:41
Raaz444Raaz444
386
386
2
Should the data be inserted big- or little-endian? What is your processor, big- or little-endian?
– Fiddling Bits
Nov 20 '18 at 16:42
add a comment |
2
Should the data be inserted big- or little-endian? What is your processor, big- or little-endian?
– Fiddling Bits
Nov 20 '18 at 16:42
2
2
Should the data be inserted big- or little-endian? What is your processor, big- or little-endian?
– Fiddling Bits
Nov 20 '18 at 16:42
Should the data be inserted big- or little-endian? What is your processor, big- or little-endian?
– Fiddling Bits
Nov 20 '18 at 16:42
add a comment |
1 Answer
1
active
oldest
votes
You should change
memset (&pointer_p, 0, size); // size = 497 bytes
to
memset (pointer_p, 0, size); // size = 497 bytes
Then, assuming little endian
((char *)pointer_p)[497] = A & 0xFFu;
((char *)pointer_p)[498] = (A >> 8) & 0xFFu;
((char *)pointer_p)[499] = (A >> 16) & 0xFFu;
For big endian just change the indices
((char *)pointer_p)[499] = A & 0xFFu;
((char *)pointer_p)[498] = (A >> 8) & 0xFFu;
((char *)pointer_p)[497] = (A >> 16) & 0xFFu;
It's not clear how this is supposed to work with your U16 elements.
answered Nov 20 '18 at 17:34
Doug CurrieDoug Currie
35.6k77108
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
You should change
memset (&pointer_p, 0, size); // size = 497 bytes
to
memset (pointer_p, 0, size); // size = 497 bytes
Then, assuming little endian
((char *)pointer_p)[497] = A & 0xFFu;
((char *)pointer_p)[498] = (A >> 8) & 0xFFu;
((char *)pointer_p)[499] = (A >> 16) & 0xFFu;
For big endian just change the indices
((char *)pointer_p)[499] = A & 0xFFu;
((char *)pointer_p)[498] = (A >> 8) & 0xFFu;
((char *)pointer_p)[497] = (A >> 16) & 0xFFu;
It's not clear how this is supposed to work with your U16 elements.
answered Nov 20 '18 at 17:34
Doug CurrieDoug Currie
35.6k77108
add a comment |
You should change
memset (&pointer_p, 0, size); // size = 497 bytes
to
memset (pointer_p, 0, size); // size = 497 bytes
Then, assuming little endian
((char *)pointer_p)[497] = A & 0xFFu;
((char *)pointer_p)[498] = (A >> 8) & 0xFFu;
((char *)pointer_p)[499] = (A >> 16) & 0xFFu;
For big endian just change the indices
((char *)pointer_p)[499] = A & 0xFFu;
((char *)pointer_p)[498] = (A >> 8) & 0xFFu;
((char *)pointer_p)[497] = (A >> 16) & 0xFFu;
It's not clear how this is supposed to work with your U16 elements.
answered Nov 20 '18 at 17:34
Doug CurrieDoug Currie
35.6k77108
add a comment |
You should change
memset (&pointer_p, 0, size); // size = 497 bytes
to
memset (pointer_p, 0, size); // size = 497 bytes
Then, assuming little endian
((char *)pointer_p)[497] = A & 0xFFu;
((char *)pointer_p)[498] = (A >> 8) & 0xFFu;
((char *)pointer_p)[499] = (A >> 16) & 0xFFu;
For big endian just change the indices
((char *)pointer_p)[499] = A & 0xFFu;
((char *)pointer_p)[498] = (A >> 8) & 0xFFu;
((char *)pointer_p)[497] = (A >> 16) & 0xFFu;
It's not clear how this is supposed to work with your U16 elements.
answered Nov 20 '18 at 17:34
Doug CurrieDoug Currie
35.6k77108
You should change
memset (&pointer_p, 0, size); // size = 497 bytes
to
memset (pointer_p, 0, size); // size = 497 bytes
Then, assuming little endian
((char *)pointer_p)[497] = A & 0xFFu;
((char *)pointer_p)[498] = (A >> 8) & 0xFFu;
((char *)pointer_p)[499] = (A >> 16) & 0xFFu;
For big endian just change the indices
((char *)pointer_p)[499] = A & 0xFFu;
((char *)pointer_p)[498] = (A >> 8) & 0xFFu;
((char *)pointer_p)[497] = (A >> 16) & 0xFFu;
It's not clear how this is supposed to work with your U16 elements.
answered Nov 20 '18 at 17:34
Doug CurrieDoug Currie
35.6k77108
edited Nov 20 '18 at 17:57
answered Nov 20 '18 at 17:34
Doug CurrieDoug Currie
35.6k77108
answered Nov 20 '18 at 17:34
Doug CurrieDoug Currie
35.6k77108
answered Nov 20 '18 at 17:34
Doug CurrieDoug Currie
35.6k77108
35.6k77108
add a comment |
add a comment |
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2
Should the data be inserted big- or little-endian? What is your processor, big- or little-endian?
– Fiddling Bits
Nov 20 '18 at 16:42