RealView Compilation Tools - ARM Information Center

Compiler-specific Features
Example
This example demonstrates how pack(2) aligns integer variable b to a 2-byte boundary.
typedef struct
{
char a;
int b;
} S;
#pragma pack(2)
typedef struct
{
char a;
int b;
} SP;
S var = { 0x11, 0x44444444 };
SP pvar = { 0x11, 0x44444444 };
The layout of S is as shown in Figure 4-1, while the layout of SP is as shown in
Figure 4-2. In Figure 4-2, x denotes one byte of padding.
0 1 2 3
a padding
4 5 6 7
b b b b
Figure 4-1 Nonpacked structure S
0 1 2 3
a x b b
4 5
b b
Note
SP is a 6-byte structure. There is no padding after b.
Figure 4-2 Packed structure SP
See also
• __packed on page 4-11
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