Extensions for vector processing support

This section has information on the IBM® Open XL C/C++ extensions to support the AltiVec Application Programming Interface specification and features that are IBM extensions to the AltiVec Application Programming Interface specification.

The vector extensions are only accepted when all of the following conditions are met:

The -mcpu option is set to a target architecture that supports vector processing instructions. For example, an architecture that supports the VSX instruction set extensions, such as POWER8, requires -mcpu=power8.
The -maltivec option is in effect.

Table 1. IBM Open XL C/C++ extensions to support the AltiVec Application Programming Interface specification
Language feature	Discussed in:
Vector programming language extensions	Vector types, Vector literals

The following features are IBM extensions to the AltiVec Application Programming Interface specification:

Table 2. IBM Open XL C and C++ extensions to the AltiVec Application Programming Interface specification
Language extension	Discussed in:
`__pixel`, `pixel`, `__vector`, and `vector` keywords	N/A
Indirection operator `*` applied to vector types	N/A
Initialization of vectors	Initialization of vectors
Pointer arithmetic on vector types	Pointer arithmetic
Unary and binary operators	Unary and binary operators
Vector types as arguments to `vec_step`	The vec_step operator
Vector type casts	Vector type casts
Vector subscripting operator [ ]	Vector subscripting operator [ ]