help: sizeof(struct)
lium@i-net.com.cn
lium@i-net.com.cn
Mon Jul 15 19:49:00 GMT 2002
Hi,
there is a struct like following:
struct test {
unsigned char a;
unsigned int b;
unsigned char c;
}
my target machine is ARM7TDMI, my gcc version is: "gcc version 3.0". when i use sizeof(struct test), it return 0xc. if i add 'packed' attribute, sizeof return 6. but i need the sizeof macro return 9.
the follow is memory layout:
Normal: +---+---+---+---+ Packed: +---+---+---+---+
|///|///|///|///| |///|///|///|///|
+---+---+---+---+ +---+---+---+---+
| a | | | | | a | b | b | b |
+---+---+---+---+ +---+---+---+---+
| b | b | b | b | | b | c |///|///|
+---+---+---+---+ +---+---+---+---+
| c | | | | |///|///|///|///|
+---+---+---+---+ +---+---+---+---+
Wanted: +---+---+---+---+
|///|///|///|///|
+---+---+---+---+
| a | | | |
+---+---+---+---+
| b | b | b | b |
+---+---+---+---+
| c |///|///|///|
+---+---+---+---+
would you please tell me which compiling option can do so.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Rabbit.GIF
Type: image/gif
Size: 1488 bytes
Desc: not available
URL: <https://gcc.gnu.org/pipermail/gcc-help/attachments/20020715/87b1aa3f/attachment.gif>
More information about the Gcc-help
mailing list