OpenMP Compiler GCC Clang
A Compiler comparison by Michael Larabel looking at the OpenMP LLVM Clang performance against GCC. Using Intel's Clang LLVM Compiler-RT and Intel OpenMP Runtime Library code on Ubuntu Linux. Benchmarks for a future article on Phoronix.com. Also a few other non-OMP benchmarks in this result file...


GCC 4.9.0: 

	Processor: Intel Core i7-3517U @ 1.90GHz (4 Cores), Motherboard: ASUS UX32VDA v1.0, Chipset: Intel 3rd Gen Core DRAM, Memory: 4096MB, Disk: 2 x 128GB SanDisk SD5SF212, Graphics: Intel HD 4000 512MB (1150MHz), Audio: Realtek ALC269VB, Network: Intel Centrino Advanced-N 6235

	OS: Ubuntu 14.04, Kernel: 3.13.0-24-generic (x86_64), Desktop: Unity 7.2.0, Display Server: X Server 1.15.1, Display Driver: intel 2.99.910, OpenGL: 3.3 Mesa 10.1.0, Compiler: GCC 4.9.0, File-System: ext4, Screen Resolution: 1920x1080

Clang 3.4 Stock: 

	Processor: Intel Core i7-3517U @ 1.90GHz (4 Cores), Motherboard: ASUS UX32VDA v1.0, Chipset: Intel 3rd Gen Core DRAM, Memory: 4096MB, Disk: 2 x 128GB SanDisk SD5SF212, Graphics: Intel HD 4000 512MB (1150MHz), Audio: Realtek ALC269VB, Network: Intel Centrino Advanced-N 6235

	OS: Ubuntu 14.04, Kernel: 3.13.0-24-generic (x86_64), Desktop: Unity 7.2.0, Display Server: X Server 1.15.1, Display Driver: intel 2.99.910, OpenGL: 3.3 Mesa 10.1.0, Compiler: Clang 3.4-1ubuntu3, File-System: ext4, Screen Resolution: 1920x1080

Clang 3.4 Intel OpenMP: 

	Processor: Intel Core i7-3517U @ 1.90GHz (4 Cores), Motherboard: ASUS UX32VDA v1.0, Chipset: Intel 3rd Gen Core DRAM, Memory: 4096MB, Disk: 2 x 128GB SanDisk SD5SF212, Graphics: Intel HD 4000 512MB (1150MHz), Audio: Realtek ALC269VB, Network: Intel Centrino Advanced-N 6235

	OS: Ubuntu 14.04, Kernel: 3.13.0-24-generic (x86_64), Desktop: Unity 7.2.0, Display Server: X Server 1.15.1, Display Driver: intel 2.99.910, OpenGL: 3.3 Mesa 10.1.0, Compiler: Clang 3.4 + LLVM 3.4, File-System: ext4, Screen Resolution: 1920x1080


CLOMP 3.3
Static OMP Speedup
Speedup > Higher Is Better
GCC 4.9.0 . 2.69 |=============================================================


TTSIOD 3D Renderer 2.2z
Phong Rendering With Soft-Shadow Mapping
FPS > Higher Is Better
GCC 4.9.0 .............. 64.35 |===============================================
Clang 3.4 Intel OpenMP . 64.18 |===============================================


GraphicsMagick 1.3.19
Operation: Blur
Iterations Per Minute > Higher Is Better
GCC 4.9.0 .............. 100 |=================================================
Clang 3.4 Stock ........ 64  |===============================
Clang 3.4 Intel OpenMP . 88  |===========================================


GraphicsMagick 1.3.19
Operation: Sharpen
Iterations Per Minute > Higher Is Better
GCC 4.9.0 .............. 64 |==================================================
Clang 3.4 Stock ........ 42 |=================================
Clang 3.4 Intel OpenMP . 59 |==============================================


GraphicsMagick 1.3.19
Operation: Resizing
Iterations Per Minute > Higher Is Better
GCC 4.9.0 ....... 114 |========================================================
Clang 3.4 Stock . 87  |===========================================


GraphicsMagick 1.3.19
Operation: HWB Color Space
Iterations Per Minute > Higher Is Better
GCC 4.9.0 .............. 134 |=================================================
Clang 3.4 Stock ........ 110 |========================================
Clang 3.4 Intel OpenMP . 113 |=========================================


GraphicsMagick 1.3.19
Operation: Local Adaptive Thresholding
Iterations Per Minute > Higher Is Better
GCC 4.9.0 .............. 70 |==================================================
Clang 3.4 Stock ........ 68 |=================================================
Clang 3.4 Intel OpenMP . 68 |=================================================


Timed Apache Compilation 2.4.7
Time To Compile
Seconds < Lower Is Better
GCC 4.9.0 .............. 60.08 |===============================================
Clang 3.4 Stock ........ 43.35 |==================================
Clang 3.4 Intel OpenMP . 41.94 |=================================


C-Ray 1.1
Total Time
Seconds < Lower Is Better
GCC 4.9.0 .............. 74.00 |=========================================
Clang 3.4 Stock ........ 83.96 |===============================================
Clang 3.4 Intel OpenMP . 83.91 |===============================================


Smallpt 1.0
Global Illumination Renderer; 100 Samples
Seconds < Lower Is Better
GCC 4.9.0 .............. 239 |========================
Clang 3.4 Stock ........ 484 |=================================================
Clang 3.4 Intel OpenMP . 238 |========================


FLAC Audio Encoding 1.3.0
WAV To FLAC
Seconds < Lower Is Better
GCC 4.9.0 .............. 6.02 |===========================================
Clang 3.4 Stock ........ 6.65 |================================================
Clang 3.4 Intel OpenMP . 6.66 |================================================


LAME MP3 Encoding 3.99.3
WAV To MP3
Seconds < Lower Is Better
GCC 4.9.0 .............. 15.93 |===============================================
Clang 3.4 Stock ........ 15.06 |============================================
Clang 3.4 Intel OpenMP . 15.06 |============================================