1. Computers
  2. Display Drivers
  3. Graphics Cards
  4. Memory
  5. Motherboards
  6. Processors
  7. Software
  8. Storage
  9. Operating Systems


Facebook RSS Twitter Twitter Google Plus


Phoronix Test Suite

OpenBenchmarking Benchmarking Platform
Phoromatic Test Orchestration

R600 LLVM Back-End Gets Indirect Addressing Support

Mesa

Published on 22 January 2013 05:33 PM EST
Written by Michael Larabel in Mesa
4 Comments

The open-source Radeon R600 LLVM back-end has finally received support for indirect memory addressing.

AMD's Tom Stellard put out the 1200 line patch today that enables indirect addressing support within the R600 LLVM GPU target. Indirect addressing support has been one of the major limitations so far in this Radeon LLVM back-end. This back-end can be optionally used by the R600 Gallium3D driver for its shader compiler and is a key requirement for the Radeon OpenCL/GPGPU compute support. As far as end-users are concerned, the lack of indirect addressing support has made the LLVM back-end shader compiler not work for some OpenGL games like Unigine and Sauerbraten. (See Trying Out AMD's Radeon Gallium3D LLVM Compiler.)

Stellard writes in his mailing list message that for now this indirect addressing is R600-only with the Radeon HD 7000 "Southern islands" implementation still missing a few callbacks used during this process. He additionally writes, "At the moment R600 only supports array sizes of 16 dwords or less. Register packing of vector types is currently disabled, which means that a vec4 is stored in T0_X, T1_X, T2_X, T3_X, rather than T0_XYZW. In order to correctly pack registers in all cases, we will need to implement an analysis pass for R600 that determines the correct vector width for each array."

The R600 LLVM GPU back-end was removed from Mesa and merged into upstream LLVM. This R600 LLVM indirect addressing support will soon likely be merged into Tom Stellard's R600 LLVM repository followed by eventually making it into the next R600 GPU LLVM pull that should end up being released as part of LLVM 3.3 later this year.

About The Author
Michael Larabel is the principal author of Phoronix.com and founded the web-site in 2004 with a focus on enriching the Linux hardware experience and being the largest web-site devoted to Linux hardware reviews, particularly for products relevant to Linux gamers and enthusiasts but also commonly reviewing servers/workstations and embedded Linux devices. Michael has written more than 10,000 articles covering the state of Linux hardware support, Linux performance, graphics hardware drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and OpenBenchmarking.org automated testing software. He can be followed via and or contacted via .
Latest Articles & Reviews
  1. AMD Radeon R9 290 OpenGL On Ubuntu 15.04: Catalyst vs. RadeonSI Gallium3D
  2. Ubuntu 15.04 Offers Faster OpenGL For AMD Radeon GPUs On Open-Source
  3. Ubuntu 15.04 Brings Some Graphics Performance Improvements For Intel Haswell
  4. Sub-$20 802.11n USB WiFi Adapter That's Linux Friendly
  5. The Lenovo T450s Is Working Beautifully With Linux
  6. Linux 4.0 SSD EXT4 / Btrfs / XFS / F2FS Benchmarks
Latest Linux News
  1. GTX 750 Maxwell Acceleration Starts Working On Nouveau With Linux 4.1
  2. Reasons To Make A PTS/OB Test Profile For Your Software
  3. Vivaldi TP3 Browser Adds Native Window Support On Linux
  4. A Brief Update On Fwupd For Linux Firmware Updating Of Devices
  5. Upgrading To KDE Plasma 5.3 On Kubuntu 15.04
  6. Ubuntu 15.10 Plans Being Discussed Next Week
  7. KDE Plasma 5.3 Released: Expands On Widgets, Bluetooth, PM
  8. Making It Easier To Deploy CUDA On Fedora
  9. GCC 4.9.2 vs. GCC 5 Benchmarks On An Intel Xeon Haswell
  10. Intel Haswell/Broadwell Power Use On Linux Still Moving Lower
Most Viewed News This Week
  1. Ubuntu's Desktop-Next Switching From .DEBs To Snappy
  2. Systemd Kills Off Shutdownd
  3. KDBUS Still Hasn't Been Pulled, Might Not Land For Linux 4.1
  4. My Favorite Computer Desk Of The Past Decade For Less Than $100
  5. AMD Open-Sources "Addrlib" From Catalyst
  6. Qt Creator 3.4 Brings C++ Programming Improvements & More
  7. Debian 8.0 Jessie Is Ready For Release This Weekend
  8. GIMP's Porting To GTK3 Continues