OpenMP Issues:Broadcast Common Blocks

common /cc/ cdata

common /dd/ ddata

c initialization

cdata = ...

ddata = ...

C$OMP PARALEL

C$OMP+COPYIN(/cc/, /dd/)

call main_subroutine()

C$END PARALLEL

Issues in Seismic:

• At the start of the parallel region is it not yet known which common blocks need to be copied in.

• Solution: copy-in all common blocks ® Overhead

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