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

Understanding The New & Faster A3XX Compiler

Mesa

Published on 06 February 2014 05:37 AM EST
Written by Michael Larabel in Mesa
Comment On This Article

Talked about on Phoronix a few days ago was a new Gallium3D shader compiler for the Freedreno driver in its support of the Adreno A3xx hardware. Here's more information on this new GL shader compiler and the performance wins and benefits it provides.

Rob Clark, the principal author of the Freedreno Gallium3D driver and the one behind this new A3xx compiler, has written a blog post detailing the graphics compiler improvements.

Those interested in the low-level details of the new Freedreno A3xx compiler can read his post in full. Some highlights include:

- In terms of the previous A3xx compiler design: "The original a3xx compiler was more of a simple TGSI translator. It translated each TGSI opcode into a simple sequence of one or more native instructions...The simple TGSI translator approach works fine with simple shader ISA's. It worked ok for a2xx, other than slightly suboptimal register usage. But the problem is that a3xx (and a4xx) is not such a simple instruction set architecture. In particular, the instruction scheduling required that the compiler be aware of the shader instruction pipeline(s)."

- With the new compiler design: " First thing I wanted to do before adding a lot more complexity is to rip out a bunch of code. With that in mind I implemented a generic TGSI lowering pass, to replace about a dozen opcodes with sequences of equivalent simpler instructions. This probably should be made configurable and moved to util, I think most of the lowerings would be useful to other gallium drivers...The next step was to turn ir3 (the a3xx IR), which originates from the fdre-a3xx shader assembler into something more useful."

- The OpenGL ES 2.0 es2gears benchmark ran around 435 FPS for the original Freedreno shader compiler but is now scoring about 539 FPS with the new compiler.

- Games like SuperTuxKart are now rendering correctly where they would not render properly with the old compiler.

Overall, Freedreno is in the best shape among the current open-source, reverse-engineered ARM Linux graphics drivers.

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. MSI X99S SLI PLUS On Linux
  2. NVIDIA GeForce GTX 970 Offers Great Linux Performance
  3. CompuLab Intense-PC2: An Excellent, Fanless, Mini PC Powered By Intel's i7 Haswell
  4. From The Atom 330 To Haswell ULT: Intel Linux Performance Benchmarks
Latest Linux Articles
  1. Open-Source Radeon 2D Performance Is Better With Ubuntu 14.10
  2. RunAbove: A POWER8 Compute Cloud With Offerings Up To 176 Threads
  3. 6-Way Ubuntu 14.10 Linux Desktop Benchmarks
  4. Ubuntu 14.10 XMir System Compositor Benchmarks
Latest Linux News
  1. Dead Island GOTY Now Available On Linux/SteamOS
  2. Ubuntu 14.04 In The Power8 Cloud From RunAbove
  3. KDE With Theoretical Client-Side Decorations, Windows 10 Influence
  4. Sandusky Lee: Great Cabinets For Storing All Your Computer Gear
  5. Fedora 21 Beta & Final Release Slip Further
  6. Mesa 10.3.2 Has A Couple Bug-Fixes
  7. RadeonSI/R600g HyperZ Support Gets Turned Back On
  8. openSUSE Factory & Tumbleweed Are Merging
  9. More Fedora Delays: Fedora 21 Beta Slips
  10. Mono Brings C# To The Unreal Engine 4
Latest Forum Discussions
  1. Users/Developers Threatening Fork Of Debian GNU/Linux
  2. Updated and Optimized Ubuntu Free Graphics Drivers
  3. HOPE: The Ease Of Python With The Speed Of C++
  4. Use Ubuntu MATE 14.10 Make it an official distro.
  5. Debian Is Back To Discussing Init Systems, Freedom of Choice
  6. AMD Radeon VDPAU Video Performance With Gallium3D
  7. Ubuntu 16.04 Might Be The Distribution's Last 32-Bit Release
  8. Linux hacker compares Solaris kernel code: