-qvecnvol

Description

Specifies whether to use volatile or non-volatile vector registers. Where volatile vector registers are those registers whose value is not preserved across function calls or across save context, jump or switch context system library functions.-qvecnvol instructs the compiler to use both volatile and non-volatile vector registers while -qnovecnvol instructs the compiler to use only volatile vector registers. This option is required for programs where there is risk of interaction between modules built with AIX libraries prior to AIX 5.3 with 5300-03 and vector register use. Restricting the compiler to use only volatile registers will make your vector programs safe but it potentially forces the compiler to store vector data to memory more often and therefore results in reducing performance.

Syntax

Read syntax diagramSkip visual syntax diagram        .-novecnvol-.
>>- -q--+-vecnvol---+------------------------------------------><

Notes

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