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

Mozilla Spots Massive Performance Regression In GCC

Compiler

Published on 25 June 2010 10:16 AM EDT
Written by Michael Larabel in Compiler
10 Comments

Mozilla developers on the GCC mailing list have been expressing what they describe as a "massive performance regression" and "what might be the biggest compiler-upgrade-related performance difference we've seen at Mozilla." The Mozilla developers have upgraded from GCC 4.3 to GCC 4.5, which was released in April, and now they are experiencing massive slowdowns.

Taras Glek of Mozilla reports that with this newest release of the GNU Compiler Collection they are experiencing 4-19% slowdowns on average with their automated benchmarks on their 32-bit and 64-bit Linux builds. The only case where there wasn't a slowdown was with the 64-bit SunSpider JavaScript benchmark where it sped up by 8% when being built under GCC 4.5. Some of these Mozilla slowdowns after the GCC upgrade are discussed here and here. The start of the mailing list discussion can be found here.

Because of these performance shortcomings on GCC 4.5, Mozilla is reconsidering their switch to this newest compiler release. At least because Mozilla has an automated benchmarking infrastructure in place, they were able to spot this issue timely themselves rather than waiting for us or others to spot the problem.

Initial thoughts on these major regressions caused by GCC are the Mozilla developers building Firefox with flags for size optimizations rather than speed and possible regressions from code inlining. Mozilla was originally switching to GCC 4.5 due to its newly-introduced plug-in support and the ability to build Firefox with PGO (Profile-Guided Optimizations).

Following the release of GCC 4.5.0 in mid-April we published our own GCC 4.5 benchmarks and GCC vs. Clang/LLVM benchmarks.

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. NVIDIA's $1000+ GeForce GTX TITAN X Delivers Maximum Linux Performance
  2. OS X 10.10 vs. Ubuntu 15.04 vs. Fedora 21 Tests: Linux Sweeps The Board
  3. The New Place Where Linux Code Is Constantly Being Benchmarked
  4. 18-GPU NVIDIA/AMD Linux Comparison Of BioShock: Infinite
  5. Phoronix Test Suite 5.6 Adds New Phoromatic Enterprise Benchmarking Features
  6. OpenGL Threaded Optimizations Responsible For NVIDIA's Faster Performance?
Latest Linux News
  1. Shadow Warrior Is Being Released For Linux Next Week
  2. Intel Pushes A Bunch Of Broadwell Code Into Coreboot
  3. Open-Source Driver Fans Will Love NVIDIA's New OpenGL Demo
  4. GHC 7.10.1 Brings New Compiler Features
  5. Git 2.4.0-rc0 Does A Ton Of Polishing
  6. The Most Common, Annoying Issue When Benchmarking Ubuntu On Many Systems
  7. Mesa Is At Nearly 1,500 Commits This Year
  8. Gestures & Other GTK3 Features For LibreOffice
  9. It's Now Easier To Try PHP 7 On Fedora & RHEL
  10. BQ Is Cleaning Up Their Aquaris E4.5 Ubuntu Kernel
Most Viewed News This Week
  1. Introducing The Library Operating System For Linux
  2. AMD Is Hiring Two More Open-Source Linux GPU Driver Developers
  3. New SecureBoot Concerns Arise With Windows 10
  4. GNOME Shell & Mutter 3.16.0 Released
  5. GNU Nano 2.4.0 Brings Complete Undo System, Linter Support & More
  6. Systemd Change Allows For Stateless Systems With Tmpfs
  7. Red Hat Is Rolling Out A VirtIO DRM/KMS GPU Driver
  8. GCC 5 Compiler Is Getting Close To Being Released
%%CLICK_URL_UNESC%%