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

A Shader Disassembler For Radeon Gallium3D

AMD

Published on 29 December 2012 07:30 PM EST
Written by Michael Larabel in AMD
Comment On This Article

Vadim Girlin has published a new Mesa branch that integrates a shader disassembler and ISA information tables within the AMD R600 Gallium3D graphics driver.

For aiding in the debugging process and for improving the Radeon Gallium3D driver with regard to shader optimizations, Vadim Girlin is looking to have a shader disassembler within the driver itself.

Adding the disassembler to the Gallium3D driver is small and is only used when an environment variable is set, but adding the ISA information tables is what makes the work large due to all of the data about the different possible shader instructions. Vadim says, "I had the complete tables already prepared for other work on shader optimization, so I think that it makes sense to use other stuff as well while I'm at it."

In terms of the Radeon shader disassembler capabilities:
All bytecode structs now contain the indices of instruction records in the tables instead of native opcodes - this allows easy access to all related information in the tables - e.g. number of operands for alu instructions, native opcode for current chip class, etc. Also this allows to use single id for instruction even if it has different opcodes on different chips, that is, e.g. we don't have to check for all possible opcodes to say that current instruction is DOT4, we can simply compare alu->op with ALU_OP2_DOT4 constant that represents the index in the table, so this simplifies the processing of the shader code. Also alu table contains the information about allowed slots (vector/scalar) for different chip classes and some additional flags - e.g. instead of comparing some opcode with all possible KILLxx opcodes we can simply check the flag that is set in the table for all KILLxx instructions.
Vadim is currently seeking comments on this R600g shader disassembler, per this mailing list thread. The Mesa branch containing the changes can be found in his r600-disasm Mesa Git branch. Tapping the shader disassembler is just a matter of setting the R600_DUMP_SHADERS environment variable to a value of 2 or 3 (the latter also provides the old shader dumps as if passing R600_DUMP_SHADERS=1 at present).

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. Linux Compiler Benchmarks Of LLVM Clang 3.5 vs. LLVM Clang 3.6-rc1
  2. Intel Broadwell HD Graphics 5500: Windows 8.1 vs. Linux
  3. Linux Benchmarks Of NVIDIA's Early 2015 GeForce Line-Up
  4. NVIDIA GeForce GTX 960: A Great $200 GPU For Linux Gamers
  5. Disk Encryption Tests On Fedora 21
  6. Xonotic 0.8 Performance With The Open-Source AMD/NVIDIA Gallium3D Drivers
Latest Linux News
  1. Ubuntu's Mir Gains Server-Side Platform Probing
  2. Broadwell Linux Ultrabook Running MUCH Cooler Than Haswell
  3. LZHAM 1.0 Lossless Data Compression Codec Released
  4. LibreOffice 4.4 Is Coming Soon With New Features
  5. Linux Users Upset By Chromium's Busted HiDPI Support
  6. BPF Backend Merged Into LLVM To Make Use Of New Kernel Functionality
  7. Dying Light Is Headed To Linux, SteamOS
  8. Wayland 1.6.1 & Weston 1.6.1 Released
  9. Mesa 10.4.3 Brings A Bunch Of Fixes For The Direct3D "Nine" Support
  10. Intel Has A Few More Graphics Changes For The Linux 3.20 Kernel
Most Viewed News This Week
  1. Windows 10 To Be A Free Upgrade: What Linux Users Need To Know
  2. CoreOS Moves From Btrfs To EXT4 + OverlayFS
  3. Google Admin Encourages Trying Btrfs, Not ZFS On Linux
  4. TraceFS: The Newest Linux File-System
  5. My Initial Intel Broadwell Linux Experience With The ThinkPad X1 Carbon
  6. Mozilla's Servo Still On Track For 2015 Alpha Release
  7. Fedora 23 Likely To Pursue Wayland By Default
  8. Keith Packard Leaves Intel's Linux Graphics Work