(6.5.2.1) The padding and alignment of members of structures.
Table E–5 Padding and Alignment of Structure Members|
Type |
Alignment Boundary |
Byte Alignment |
|---|---|---|
|
char |
Byte |
1 |
|
short |
Halfword |
2 |
|
int |
Word |
4 |
|
long (SPARC) v8 |
Word |
4 |
|
long (SPARC) v9 |
Doubleword |
8 |
|
float (SPARC) |
Word |
4 |
|
double (SPARC) |
Doubleword (SPARC) Word (x86) |
8 (SPARC) 4 (x86) |
|
long double (SPARC) v8 |
Doubleword (SPARC) Word (x86) |
8 (SPARC) 4 (x86) |
|
long double (SPARC) v9 |
Quadword |
16 |
|
pointer (SPARC) v8 |
Word |
4 |
|
pointer (SPARC) v9 |
Quadword |
8 |
|
long long |
Doubleword (SPARC) Word (x86) |
8 (SPARC) 4 (x86) |
Structure members are padded internally, so that every element is aligned on the appropriate boundary.
Alignment of structures is the same as its more strictly aligned member. For example, a struct with only chars has no alignment restrictions, whereas a struct containing a double would be aligned on an 8-byte boundary.
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