Earlier this month I wrote about Bitcoin Mining coming to the open-source Radeon Linux GPU driver
. In the weeks since, Tom Stellard of AMD has made more improvements to the AMD R600 LLVM back-end that benefit the performance of Bitcoin mining.
The OpenCL/GPGPU stack of the open-source Radeon Gallium3D Linux graphics driver still is not as fast or feature-complete as the proprietary AMD Catalyst driver, but it's still being raised. Until earlier this month, the open-source AMD Radeon OpenCL support was only useful for running a few sample OpenCL demos but now the popular "bfgminer" Bitcoin mining application can handle the Gallium3D stack that uses a LLVM back-end for communicating with the Radeon HD 5000 series and beyond.
On Monday afternoon, Tom Stellard post a new set of patches
that provide for bfgminer optimizations with the R600 LLVM back-end.
The patches that provide for Bitcoin mining optimizations on the Radeon open-source driver include 64-bit load/store support, a pattern for the SHA-256 Ma function, a change for the BFI_INT instruction, and support for expanding vector or/shl/srl/xor nodes.