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.org

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 Linux Hardware Reviews
  1. The Power Consumption & Efficiency Of Open-Source GPU Drivers
  2. AMD R600g/RadeonSI Performance On Linux 3.16 With Mesa 10.3-devel
  3. Intel Pentium G3258 On Linux
  4. SilverStone Precision PS10
Latest Linux Articles
  1. Nouveau vs. Radeon vs. Intel Tests On Linux 3.16, Mesa 10.3-devel
  2. KVM Benchmarks On Ubuntu 14.10
  3. X.Org Server 1.16 Officially Released With Terrific Features
  4. Ubuntu With Linux 3.16 Smashes OS X 10.9.4 On The MacBook Air
Latest Linux News
  1. Git 2.1 To Further Mainline Windows Support Patches
  2. Debian 8.0 Jessie Is Settling For Linux 3.16
  3. Meson: A Next-Gen Build System Showing Promise
  4. Linux 3.16-rc7 Calms Things Down For The Linux 3.16 Kernel
  5. Open-Source AMD Users Report Hawaii GPU Acceleration Is Working
  6. Linus Torvalds On GCC 4.9: Pure & Utter Crap
  7. Cauldron 2014: GCC & LLVM Will Look To Collaborate More
  8. GCC Receives ACM Programming Languages Software Award
  9. KDE 4.14 Beta 3 Released
  10. A New Video Has Us Real Excited About The New UT For Linux
Latest Forum Discussions
  1. Updated and Optimized Ubuntu Free Graphics Drivers
  2. ASRock AM1H-ITX: One Of The Best AM1 Mini-ITX Motherboards
  3. Debian + radeonsi
  4. Open-source drivers on ATI R7 260X
  5. Table test
  6. How To Setup Radeon DPM On Ubuntu Linux
  7. New build, first Linux PC, what could go wrong? ;)
  8. AMD "Hawaii" Open-Source GPU Acceleration Still Not Working Right