For basic (scalar) types, the minimum alignment of an object is the size of its type. The minimum alignment for an object with an array type is that specified by the type of its elements.
For general information about data types, see Section 5.3. Table 6-1 lists register and memory storage for various data types:
| Data Type | Register Storage | Memory Storage |
|---|---|---|
| char | Bits 0-7 of register | 8 bits aligned to 8-bit boundary |
| unsigned char | Bits 0-7 of register | 8 bits aligned to 8-bit boundary |
| short | Bits 0-15 of register | 16 bits aligned to 16-bit boundary |
| unsigned short | Bits 0-15 of register | 16 bits aligned to 16-bit boundary |
| int | Bits 0-31 of register | 32 bits aligned to 32-bit boundary |
| unsigned int | Bits 0-31 of register | 32 bits aligned to 32-bit boundary |
| long | Entire scalar register or bits 0-63 of vector register | 64 bits aligned to 64-bit boundary |
| unsigned long | Entire scalar register or bits 0-63 of vector register. | 64 bits aligned to 64-bit boundary |
| enum (1) | Bits 0-31 of register or entire register | 32 bits aligned to 32-bit boundary or 64 bits aligned to 64-bit boundary |
| float | Bits 0-31 of register | 32 bits aligned to 32-bit boundary |
| double | Entire scalar register or bits 0-63 of vector register. | 64 bits aligned to 64-bit boundary |
| long double | Entire scalar register or bits 0-63 of vector register. | 64 bits aligned to 64-bit boundary |
| struct | Members are stored as their individual types require. | Storage is a multiple of the alignment to the boundary of largest member type; members are stored and aligned as their individual types require. |
| array | Members are stored as their individual types require. | Members are stored as their individual types require. All arrays inside a structure are aligned according to the type of each element in the array. |
| pointer to data member | Entire scalar register or bits 0-63 of vector register. | 64 bits aligned to 64-bit boundary |
| pointer to member function | Components stored as their individual types require | 64 bits aligned to 64-bit boundary |
| cchar | Bits 0-15 of register | 8 bits aligned to 8-bit boundary |
| cshort | Bits 0-31 of register | 16 bits aligned to 16-bit boundary |
| cint | Entire scalar register or bits 0-63 of vector register | 64 bits aligned to 32-bit boundary |
| cfloat | Entire scalar register or bits 0-63 of vector register | 64 bits aligned to 32-bit boundary |
| clong | Bits 0-127 of vector register | 128 bits aligned to 64-bit boundary |
| cdouble | Bits 0-127 of vector register | 128 bits aligned to 64-bit boundary |
For vector data types, the minimum alignment of an object is specified by the type of its elements.