LLVM Clang 3.4 Compiler Optimization Levels Benchmarking LLVM/Clang compiler optimization levels for a future article on phoronix.com. -O0: Processor: Intel Core i7 720Q @ 1.60GHz (8 Cores), Motherboard: LENOVO 4318CTO, Chipset: Intel Core DMI, Memory: 4096MB, Disk: 160GB INTEL SSDSA2M160, Graphics: NVIDIA Quadro FX 880M 1024MB (405/324MHz), Audio: Conexant CX20585, Network: Intel 82577LM Gigabit Connection + Intel Centrino Ultimate-N 6300 OS: Ubuntu 13.10, Kernel: 3.11.0-031100rc2-generic (x86_64), Desktop: Xfce 4.10, Display Server: X Server 1.14.2, Display Driver: nouveau 1.0.8, OpenGL: 3.0 Mesa 9.1.4 Gallium 0.4, Compiler: Clang 3.4 (SVN 187338) + LLVM 3.4svn, File-System: ext4, Screen Resolution: 1600x900 -O1: Processor: Intel Core i7 720Q @ 1.60GHz (8 Cores), Motherboard: LENOVO 4318CTO, Chipset: Intel Core DMI, Memory: 4096MB, Disk: 160GB INTEL SSDSA2M160, Graphics: NVIDIA Quadro FX 880M 1024MB (405/324MHz), Audio: Conexant CX20585, Network: Intel 82577LM Gigabit Connection + Intel Centrino Ultimate-N 6300 OS: Ubuntu 13.10, Kernel: 3.11.0-031100rc2-generic (x86_64), Desktop: Xfce 4.10, Display Server: X Server 1.14.2, Display Driver: nouveau 1.0.8, OpenGL: 3.0 Mesa 9.1.4 Gallium 0.4, Compiler: Clang 3.4 (SVN 187338) + LLVM 3.4svn, File-System: ext4, Screen Resolution: 1600x900 -O2: Processor: Intel Core i7 720Q @ 1.60GHz (8 Cores), Motherboard: LENOVO 4318CTO, Chipset: Intel Core DMI, Memory: 4096MB, Disk: 160GB INTEL SSDSA2M160, Graphics: NVIDIA Quadro FX 880M 1024MB (405/324MHz), Audio: Conexant CX20585, Network: Intel 82577LM Gigabit Connection + Intel Centrino Ultimate-N 6300 OS: Ubuntu 13.10, Kernel: 3.11.0-031100rc2-generic (x86_64), Desktop: Xfce 4.10, Display Server: X Server 1.14.2, Display Driver: nouveau 1.0.8, OpenGL: 3.0 Mesa 9.1.4 Gallium 0.4, Compiler: Clang 3.4 (SVN 187338) + LLVM 3.4svn, File-System: ext4, Screen Resolution: 1600x900 -Os: Processor: Intel Core i7 720Q @ 1.60GHz (8 Cores), Motherboard: LENOVO 4318CTO, Chipset: Intel Core DMI, Memory: 4096MB, Disk: 160GB INTEL SSDSA2M160, Graphics: NVIDIA Quadro FX 880M 1024MB (405/324MHz), Audio: Conexant CX20585, Network: Intel 82577LM Gigabit Connection + Intel Centrino Ultimate-N 6300 OS: Ubuntu 13.10, Kernel: 3.11.0-031100rc2-generic (x86_64), Desktop: Xfce 4.10, Display Server: X Server 1.14.2, Display Driver: nouveau 1.0.8, OpenGL: 3.0 Mesa 9.1.4 Gallium 0.4, Compiler: Clang 3.4 (SVN 187338) + LLVM 3.4svn, File-System: ext4, Screen Resolution: 1600x900 -O3: Processor: Intel Core i7 720Q @ 1.60GHz (8 Cores), Motherboard: LENOVO 4318CTO, Chipset: Intel Core DMI, Memory: 4096MB, Disk: 160GB INTEL SSDSA2M160, Graphics: NVIDIA Quadro FX 880M 1024MB (405/324MHz), Audio: Conexant CX20585, Network: Intel 82577LM Gigabit Connection + Intel Centrino Ultimate-N 6300 OS: Ubuntu 13.10, Kernel: 3.11.0-031100rc2-generic (x86_64), Desktop: Xfce 4.10, Display Server: X Server 1.14.2, Display Driver: nouveau 1.0.8, OpenGL: 3.0 Mesa 9.1.4 Gallium 0.4, Compiler: Clang 3.4 (SVN 187338) + LLVM 3.4svn, File-System: ext4, Screen Resolution: 1600x900 -Ofast: Processor: Intel Core i7 720Q @ 1.60GHz (8 Cores), Motherboard: LENOVO 4318CTO, Chipset: Intel Core DMI, Memory: 4096MB, Disk: 160GB INTEL SSDSA2M160, Graphics: NVIDIA Quadro FX 880M 1024MB (405/324MHz), Audio: Conexant CX20585, Network: Intel 82577LM Gigabit Connection + Intel Centrino Ultimate-N 6300 OS: Ubuntu 13.10, Kernel: 3.11.0-031100rc2-generic (x86_64), Desktop: Xfce 4.10, Display Server: X Server 1.14.2, Display Driver: nouveau 1.0.8, OpenGL: 3.0 Mesa 9.1.4 Gallium 0.4, Compiler: Clang 3.4 (SVN 187338) + LLVM 3.4svn, File-System: ext4, Screen Resolution: 1600x900 Timed HMMer Search 2.3.2 Pfam Database Search Seconds < Lower Is Better -O0 .... 89.33 |=============================================================== -O1 .... 30.89 |====================== -O2 .... 27.31 |=================== -Os .... 28.68 |==================== -O3 .... 27.33 |=================== -Ofast . 27.10 |=================== SciMark 2.0 Computational Test: Fast Fourier Transform Mflops > Higher Is Better -O0 .... 189.30 |============================================================== -O1 .... 189.10 |============================================================== -O2 .... 189.72 |============================================================== -Os .... 190.14 |============================================================== -O3 .... 173.57 |========================================================= -Ofast . 188.06 |============================================================= GraphicsMagick 1.3.16 Operation: Blur Iterations Per Minute > Higher Is Better -O0 .... 22 |=========================== -O1 .... 53 |================================================================== -O2 .... 53 |================================================================== -Os .... 52 |================================================================= -O3 .... 53 |================================================================== -Ofast . 53 |================================================================== GraphicsMagick 1.3.16 Operation: Sharpen Iterations Per Minute > Higher Is Better -O0 .... 10 |================== -O1 .... 35 |================================================================ -O2 .... 36 |================================================================== -Os .... 36 |================================================================== -O3 .... 36 |================================================================== -Ofast . 36 |================================================================== GraphicsMagick 1.3.16 Operation: Resizing Iterations Per Minute > Higher Is Better -O0 .... 24 |======================== -O1 .... 66 |================================================================= -O2 .... 66 |================================================================= -Os .... 66 |================================================================= -O3 .... 66 |================================================================= -Ofast . 67 |================================================================== GraphicsMagick 1.3.16 Operation: HWB Color Space Iterations Per Minute > Higher Is Better -O0 .... 36 |======================== -O1 .... 81 |======================================================= -O2 .... 80 |====================================================== -Os .... 79 |====================================================== -O3 .... 80 |====================================================== -Ofast . 97 |================================================================== GraphicsMagick 1.3.16 Operation: Local Adaptive Thresholding Iterations Per Minute > Higher Is Better -O0 .... 8 |================= -O1 .... 31 |================================================================ -O2 .... 32 |================================================================== -Os .... 30 |============================================================== -O3 .... 32 |================================================================== -Ofast . 31 |================================================================ Himeno Benchmark 3.0 Poisson Pressure Solver MFLOPS > Higher Is Better -O0 .... 127.95 |======= -O1 .... 1105.36 |============================================================ -O2 .... 1129.56 |============================================================= -Os .... 1102.68 |============================================================ -O3 .... 1055.08 |========================================================= -Ofast . 1128.50 |============================================================= Timed ImageMagick Compilation 6.8.1-10 Time To Compile Seconds < Lower Is Better -O0 .... 23.14 |====================== -O1 .... 57.37 |====================================================== -O2 .... 65.30 |============================================================== -Os .... 63.33 |============================================================ -O3 .... 65.88 |============================================================== -Ofast . 66.55 |=============================================================== Timed PHP Compilation 5.2.9 Time To Compile Seconds < Lower Is Better -O0 .... 18.55 |============================ -O1 .... 31.28 |=============================================== -O2 .... 35.51 |===================================================== -Os .... 33.44 |================================================== -O3 .... 41.97 |=============================================================== -Ofast . 42.15 |=============================================================== C-Ray 1.1 Total Time Seconds < Lower Is Better -O0 .... 208.53 |============================================================== -O1 .... 100.11 |============================== -O2 .... 103.77 |=============================== -Os .... 104.72 |=============================== -O3 .... 75.98 |======================= -Ofast . 93.63 |============================ Smallpt 1.0 Global Illumination Renderer; 100 Samples Seconds < Lower Is Better -O0 .... 770 |================================================================= -O1 .... 410 |=================================== -O2 .... 292 |========================= -Os .... 320 |=========================== -O3 .... 293 |========================= -Ofast . 275 |======================= FLAC Audio Encoding 1.3.0 WAV To FLAC Seconds < Lower Is Better -O0 .... 44.12 |=============================================================== -O1 .... 11.26 |================ -O2 .... 9.00 |============= -Os .... 11.16 |================ -O3 .... 8.86 |============= -Ofast . 8.85 |============= LAME MP3 Encoding 3.99.3 WAV To MP3 Seconds < Lower Is Better -O0 .... 67.47 |=============================================================== -O1 .... 23.55 |====================== -O2 .... 22.72 |===================== -Os .... 23.04 |====================== -O3 .... 22.64 |===================== -Ofast . 22.00 |===================== N-Queens 1.0 Elapsed Time Seconds < Lower Is Better -O0 .... 1083.88 |============================================================= -O1 .... 386.21 |====================== -O2 .... 343.18 |=================== -Os .... 331.72 |=================== -O3 .... 345.38 |=================== -Ofast . 343.65 |===================