Unified Parallel C (UPC) is an extension of the C programming language designed for high performance computing on large-scale parallel machines. The language provides a uniform programming model for both shared and distributed memory hardware.

The programmer is presented with a single shared, partitioned address space, where variables may be directly read and written by any processor, but each variable is physically associated with a single processor.

UPC uses a Single Program Multiple Data (SPMD) model of computation in which the amount of parallelism is fixed at program startup time, usually with a single thread of execution per processor.

In order to express parallelism, UPC extends ISO C 99 with the following constructs:
· An explicitly parallel execution model
· A shared address space
· Synchronization primitives and a memory consistency model
· Memory management primitives UPC combines the programmability advantages of the shared memory programming paradigm and the control over data layout and performance of the message passing programming paradigm.

Berkeley UPC is a high-performance, portable and fully open-source implementation of the UPC language designed for large-scale multiprocessors, PC clusters, and clusters of shared memory multiprocessors.

Berkeley UPC is the first UPC implementation available for Mac OS X, and delivers competetive performance for supercomputing applications on the largest OS X clusters in the world, yet also provides support for UPC code development on Mac OS X laptops and desktop workstations.

Requirements:

· For OSX 10.4 you need XCode Tools v2.x, for OSX 10.3 you need v1.x

What's New in This Release: [ read full changelog ]

· Add native support for IBM BlueGene/P via new 'dcmf' network
· Upgrade portals network support to cache local memory registration
· Many small improvements to IBM LAPI support
· Fix performance and correctness problems in Myrinet GM support
· Add Pathscale compilers to supported list for Cray XT machines
· Improved support for XLC compilers on Linux
· Extend 'ibv' (InfiniBand) support to Qlogic's InfiniPath adapters
· Add/improve support for MIPSEL/Linux platforms, including SiCortex
· Extend GCCUPC support to GCCUPC 4.2.0.2 and newer
· Add user documentation for experimental UPC-level compiler optimizations (see the upcc manpage)
· Workaround for a gcc 4.x (x= 4.3.0, though our previously documented workarounds remain valid
· Add support for autoconf 2.62 and newer
· Add experimental support for ARM processors
· Misc improvements and/or fixes for MIPS, Alpha, PPC and SPARC processors

Fix the following notable bugs in 2.6.0:
· bug1847 - Fix stability problems in cygwin -pthread apps
· bug2391 - Berkeley UPC atomics failures on SGI Altix
· bug2383 - Failure to parse gcc-4.3.2's private includes
· bug2304 - 'make install' always appears up-to-date on Cygwin
· bug2209 - Provide missing documentation for IBM SP job launch
· bug2188 - Support unequal thread distribution on LAPI network
· bug2025 - Translator build failures w/ g++ >= 4.1.2
· Various code generation bugs in the source-to-source translator
· Source-to-source translator error messages on various valid inputs
· Source-to-source translator crashes on various valid inputs
· Additional bug reports resolved with improved/clarified documentation
· Additional bugs fixed in GASNet (see gasnet/ChangeLog)
· Numerous misc minor bug fixes