#pragma altivec_vrsave

Applies to C Applies to C++

Descripton

When the #pragma altivec_vrsave directive is enabled, function prologs and epilogs include code to maintain the VRSAVE register.

Syntax


Syntax Diagram

where pragma settings do the following:


on Function prologs and epilogs include code to maintain the VRSAVE register.
off Function prologs and epilogs do not include code to maintain the VRSAVE register.
allon The function containing the altivec_vrsave pragma sets all bits of the VRSAVE register to 1, indicating that all vectors are used and should be saved if a context switch occurs.

Notes

Each bit in the VRSAVE register corresponds to a vector register, and if set to 1 indicates that the corresponding vector register contains data to be saved when a context switch occurs.

This pragma can be used only within a function, and its effects apply only to the function in which it appears. Specifying this pragma with different settings within the same function will create an error condition.

Related References

General Purpose Pragmas
altivec
vrsave IBM Copyright 2003