GCC 4.9 Compiler Supports IBM's Super-Fast POWER8

While GCC 4.9 is now in a feature-freeze mode, the open-source compiler that will be introduced in 2014 has improved PowerPC support, including IBM's POWER8 architecture.

POWER8 systems aren't yet on the market but are expected to be around mid-2014. We've seen IBM making PowerPC improvements in the Linux kernel going back to last year and now with GCC 4.9 there is POWER8 CPU support. IBM announced in August that the POWER architecture is available for licensing and this includes the POWER8 Power Architecture. POWER8 processors are expected to have twelve CPU cores, 22nm manufacturing process, clock speeds up to 4GHz, and up to 96MB of L3 cache.

With the forthcoming GCC 4.9 release there is support for POWER8 processors via the -mcpu=power8 and -mtune=power8 compiler options. GCC 4.9 also picked up support for Power ISA 2.07 with Hardware Transaction Memory support, quad-word atomics, and VMX/VSX additions. The VMX/VSX additions include Crypto support, 64-bit integer, 128-bit integer, and decimal integer operations support.

The GNU Compiler Collection's libitm Transactional Memory Runtime Library has also been re-worked to have a fast-path for using the POWER architecture's Hardware Transactional Memory instructions on supported platforms. Additionally, the powerpc64le-linux platform is supported by the upcoming GCC release that supports the ELFV2 ABI.

Besides the IBM POWER improvements in GCC 4.9 there's also many other new features and new CPU support.