Differences between HPVM and SGI/Cray SHMEM

As previously mentioned, the HPVM version of SHMEM is only a subset of the SGI/Cray SHMEM library. In particular, the HPVM SHMEM library lacks:

• all cache management functions such as shmem_set_cache_int(), shmem_set_cache_line_inv(), shmem_clear_cache_inv(), shmem_udcflush() and shmem_udcflush_line(). These functions are not necessary in HPVM SHMEM because HPVM SHMEM is implemented user-level, and all communication operations go through the cache.
• shmem_collect() and shmem_fcollect(). These functions are gather operations that can collect data from many nodes and place them in the local memory of all participating nodes.
• shmem_iget() and shmem_iput(). These functions are strided versions or the normal get/put functions.
• shmem_ixget() and shmem_ixput(). These functions implement point-to-point gather/scatter operations.

The following functions exist only in HPVM SHMEM, not in SGI/Cray SHMEM:

• shmem_cget()
• shmem_cwait()
• shmem_finalize()
• shmem_initialize()

Finally, HPVM SHMEM uses 32-bit words for int (C) and INTEGER (Fortran), while SGI/Cray SHMEM uses 64-bit words.

Go to the first, previous, next, last section, table of contents.