byte alignment with Fortran allocate

[scott_palmtag]

We are investigating some instabilities with the MLK BLAS library and we found some documentation that

said arrays should be aligned on 16-bye boundaries.

It also said that arrays allocated with MALLOC are aligned on 8-byte boundaries.

Are single precision arrays allocated with Fortran ALLOCATE statements aligned on 8-byte or 16-byte boundaries?

Do we need to specify a special compiler flag to get 16-bye alignment?

Thanks,

[Steven_L_Intel1]

You can use !DEC$ ATTRIBUTES ALIGN to specify that an allocatable variable should have a particular alignment.

[scott_palmtag]

Quoting - Steve Lionel (Intel)

You can use !DEC$ ATTRIBUTES ALIGN to specify that an allocatable variable should have a particular alignment.

I guess my question is do I have to use this, or are they already 16-byte aligned?

We have over 1000 arrays that are allocated.

Thanks,

[Jugoslav_Dujic]

Quoting - scott.palmtag@gnf.com

I guess my question is do I have to use this, or are they already 16-byte aligned?

We have over 1000 arrays that are allocated.

Thanks,

Yes, I'm afraid you have to. Some find/replace with regular expression and/or keyboard macros could automate the task :-).

We had an extensive discussion on the feature recently here:

http://software.intel.com/en-us/forums/showthread.php?t=59480