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

GCC 4.8 vs. LLVM/Clang 3.3 On Intel's Core i7 4770K

Michael Larabel

Published on 21 June 2013
Written by Michael Larabel
Page 1 of 3 - 14 Comments

Complementing the earlier Phoronix article about optimized binaries for Intel Haswell CPUs via the "-march=core-avx2" Haswell compiler optimizations, in this article is a comparison of the GCC and LLVM/Clang compilers when targeting the new Core i7 4770K CPU. GCC 4.7.3, GCC 4.8.1, LLVM Clang 3.2, and LLVM Clang 3.3 were the tested compilers under Ubuntu Linux when seeing how well these different compilers optimized for Haswell.

For this testing, GCC 4.7.3/4.8.1 and LLVM Clang 3.2/3.3 were all built from source and using similar configure options for producing release-ready optimized builds. A variety of open-source C/C++ tests were carried out on the competing compilers while using the same CFLAGS/CXXFLAGS across all of the testing. All benchmarking was handled in a fully automated and reproducible manner using the Phoronix Test Suite benchmarking software for Linux, OS X, BSD, Solaris, and Windows platforms.

The CFLAGS/CXXFLAGS set for the environment were "-O3 -march=core-avx2". In Terms of the core-avx2 optimizations, see the earlier article on optimized binaries for Haswell. Both GCC 4.7 and LLVM Clang 3.2 had early support for Intel Haswell CPUs, but the support is now much more polished in the latest releases of GCC 4.8 and LLVM Clang 3.3.

This compiler comparison and testing is quite straightforward so let's get immediately to the results from this Core i7 4770K system running an Ubuntu 13.10 development snapshot with the Linux 3.10 kernel.

Latest Articles & Reviews
  1. Sub-$20 802.11n USB WiFi Adapter That's Linux Friendly
  2. The Lenovo T450s Is Working Beautifully With Linux
  3. Linux 4.0 SSD EXT4 / Btrfs / XFS / F2FS Benchmarks
  4. Linux 4.0 Hard Drive Comparison With Six File-Systems
  5. Lenovo ThinkPad T450s Broadwell Preview
  6. How Open-Source Allowed Valve To Implement VULKAN Much Faster On The Source 2 Engine
Latest Linux News
  1. GCC 5.1 RC2 Arrives, GCC 5.1 Planned For Next Week
  2. F2FS For Linux 4.1 Has New Features & Fixes
  3. Phoronix Server Upgrade This Weekend: Dual Haswell Xeons, 96GB DDR4
  4. Google's Experimental QUIC Transport Protocol Is Showing Promise
  5. Red Hat Joins Khronos, The Group Behind OpenGL & Vulkan
  6. NetworkManager Drops WiMAX Support
  7. Wine 1.7.41 Works More On Kernel Job Objects, MSI Patches
  8. Linux 4.1 Has Improvements For The Multi-Queue Block Layer
  9. X.Org Looks To Have Six Summer Projects
  10. DragonFlyBSD Pulls In GCC 5 Compiler
Most Viewed News This Week
  1. Nouveau: NVIDIA's New Hardware Is "VERY Open-Source Unfriendly"
  2. Linux 4.0 Kernel Released
  3. Microsoft Announces An LLVM-Based Compiler For .NET
  4. Linux 4.1 Brings Many Potentially Risky x86/ASM Changes
  5. Encryption Support For EXT4
  6. VirtualBox 5.0 Beta 2 Released
  7. Mozilla Start Drafting Plans To Deprecate Insecure HTTP
  8. Elementary OS 0.3 "Freya" Now Available