topic vector nontemporal in Fortran in Software Tuning, Performance Optimization & Platform Monitoring

vector nontemporal in Fortran

Rafael_Silva — Thu, 07 Nov 2013 19:54:01 GMT

Hello guys,

I'm using "vector aligned" and "vector nontemporal" directives on my fortran code. When I was using just "vector aligned" the code was running fine, but once used also "vector nontemporal" it started to crash. I'm using -xAVX, and the directive inside the code are like that:

!DIR$ vector always aligned
!DIR$ vector nontemporal (sxx)

Where sxx is an 3D array. Is there some requirement about "nontemporal" stuff? The arrays are 64 bytes aligned, and the code was working without "nontemporal" stuff. I'm using a Intel(R) Xeon(R) CPU E3-1230 @ 3.20GHz, but I've tested on an E5-2690 also and got the same error.

even though you assert

TimP — Fri, 08 Nov 2013 12:32:53 GMT

even though you assert aligned avx code will handle misaligned (inefficiently on sandy bridge). adding nontemporal brings failure on misalignment.

Not sure if I understood. The

Rafael_Silva — Fri, 08 Nov 2013 12:46:33 GMT

Not sure if I understood. The problem is the arrays are not aligned? Because, as far as I know, they are aligned.

Is it a mistake to use the both directives?

By the way, they are 64bytes

Rafael_Silva — Fri, 08 Nov 2013 12:47:04 GMT

By the way, they are 64bytes aligned.