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<font style="font-size:90%">This Page serves as a guide for running Dhrystone benchmark on arm machines :: Please visit the [http://zenit.senecac.on.ca/wiki/index.php/Supporting_Architectures_above_armv5tel Main Project Page] </font>= About Dhrystone ==
<font style="font-size:90%">From Wikipedia, the free encyclopedia</font>
Both Whetstone and Dhrystone are synthetic benchmarks, meaning that they are simple programs that are carefully designed to statistically mimic the processor usage of some common set of programs. Whetstone, developed in 1972, originally strove to mimic typical Algol 60 programs based on measurements from 1970, but eventually became most popular in its Fortran version, reflecting the highly numerical orientation of computing in the 1960s.
== Dhrystone Fundamentals ==
<font style="font-size:90%">From ARM White Paper</font><br />
Dhrystone has a number of attributes that have led to it being widely used in the past as a
measure of CPU performance.
figure. In theory, Dhrystone should provide a basis for the comparison of processor
performances.
However, some of the apparent advantages of Dhrystone are also significant weaknesses
of the benchmark. Dhrystone numbers actually reflect the performance of the C compiler
quote accurate and meaningful Dhrystone data.
== Project Description What Dhrystone really does ==<font style="font-size:90%">From Clarify.doc (Included in Dhrystone 2.1), Rick Richardson</font><br /> <ul> <li> DHRYSTONE is a measure of processor+compiler efficiency in executing a 'typical' program. The 'typical' program was designed by measuring statistics on a great number of 'real' programs. The 'typical' program was then written by Reinhold P. Weicker using these statistics. The program is balanced according to statement type, as well as data type.</li> <li>DHRYSTONE does not use floating point. Typical programs don't.</li> <li>DHRYSTONE does not do I/O. Typical programs do, but then we'd have a whole can of worms opened up.</li> <li>DHRYSTONE does not contain much code that can be optimized by vector processors. That is why a CRAY doesn't look real fast, they weren't built to do this sort of computing.</li> <li>DHRYSTONE does not measure OS performance, as it avoids calling the O.S. The O.S. is indicated in the results only to help in identifying the compiler technology.</li> <li>DHRYSTONE is not perfect, but is a hell of a lot better than the "sieve", or "SI".</li> <li>DHRYSTONE gives results in dhrystones/second. Bigger numbers are better. As a baseline, the original IBM PC gives around 300-400 dhrystones/second with a good compiler. The fastest machines today are approaching 100,000.</li> </ul> <font style="font-size:110%"><b>Dhrystone Characteristics</b></font><blockquote><b>Strengths</b><ul><li>Written in C language Code (Allows code portability)</li><li>Small in size (An easy to understand program)</li><li>Single easy to report score (DMIPS which uses a reference VAX MIPS)</li><li>Potentially useful for 8 and 16-bit microcontroller benchmark</li></ul><b>Weaknesses</b><ul><li>Cannot hope to mimic thebreadth of applications encountered by aprocessor-based system</li><li>Dhrystone only measures a fewmathematical and basic operations</li><li>Does not measure multiply-accumulate, floating-point, SIMD, or anyother type of operations</li><li> Dhrystone’s execution islargely spent in standard C library functions,such as strcmp(),strcpy(), andmemcpy(). Compiler vendors generallyprovide these libraries that are typicallyoptimized and hand-written in assemblylanguage. While you may think you arebenchmarking a processor, you are reallybenchmarking are the compiler writer’soptimizations of the C library functions for aparticular platform</li></ul></blockquote> = Installation =<font style="font-size:110%"><b>1. Obtaining the Source Code</b></font> One of the most important defects in Dhrystone is that it is often unclear what versionis being quoted. Furthermore, since there are no "disclosure rules" or independentcertification of scores, companies and individuals are free to state, or not state, anything. Due to its non proprietary nature, individuals and companies modified their own versions of Dhrystone resulting in various alterations of the original source code. The following package is the most quoted, well used Dhrystone release. It is the cleanest/customisable Dhrystone out in the internet. [http://www.sfr-fresh.com/unix/privat/old/dhrystone-2.1.tar.gz/ Dhrystone-2.1.tar.gz] <font style="font-size:110%"><b>2. Extract the file</b></font> Extract the tarball using the command: <pre>tar xvf dhrystone-2.1.tar.gz -C destination_directory/</pre>There will be a total of 19 files once extracted. Move to the directory where the extracted files are. <font style="font-size:110%"><b>3. Edit the Makefile</b></font> Open Makefile with any text editor; '''UNCOMMENT''' (if commented) then '''EDIT''' the following fields using the '''GIVEN''' values:<blockquote>Line #25 Fedora uses -DTIME for TIME function, this field is commented out by default<pre>TIME_FUNC= -DTIME # Use times(2) for measurement</pre>Line #28Check motherboard specifications to determine the memory clock speed ( beagleboardXM runs at 166MHz DDR speed )<pre>HZ= 166 # Frequency of times(2) clock ticks</pre>Line #39This option is for C compiler<pre>OPTIMIZE= -O2 -march=armv7-a -mtune=cortex-a8 -mfpu=neon -mfloat-abi=softfp -fomit-frame-pointer # Optimization Level (generic UNIX)</pre>Line #40This option is for GCC compiler<pre>GCCOPTIM= -O2 -march=armv7-a -mtune=cortex-a8 -mfpu=neon -mfloat-abi=softfp -fomit-frame-pointer</pre></blockquote> Comment out/disable the following lines:<blockquote>Line #26 <pre>TIME_FUNC= -DTIMES # Use times(2) for measurement</pre>Line #38<pre>OPTIMIZE= -Ox -G2 # Optimization Level (MSC, 80286)</pre></blockquote> <font style="font-size:110%"><b>Makefile snapshot</b></font>[[Image:Dhry21.png|center]] <font style="font-size:110%"><b>Compiler Optimization Options</b></font> <font style="font-size:90%">Please see more about [http://gcc.gnu.org/onlinedocs/gcc/ARM-Options.html GCC ARM-Options]</font> The options used for lines #39~40 are for optimizing the dhrystone install to run specifically with '''armv7''' architecture. Optimizations provide a performance boost for the program. Removing the optimizations would result in a ''nominal'' program performance. <font style="font-size:110%"><b>4. Run "make"</b></font> Running make in the current directory should only produce warnings!! Here is an output of the make command with warnings relating to c library functions that can be ignored. <blockquote><pre>[mjeamiguel@cdot-beagleXM-0-3 dhrystone]$ makegcc -O2 -march=armv7-a -mtune=cortex-a8 -mfpu=neon -mfloat-abi=softfp -fomit-frame-pointer -DTIME -DHZ=166 dhry_1.c dhry_2.c -o gcc_dry2dhry_1.c:31: warning: conflicting types for built-in function ‘malloc’dhry_1.c: In function ‘main’:dhry_1.c:98: warning: incompatible implicit declaration of built-in function ‘strcpy’gcc -O2 -march=armv7-a -mtune=cortex-a8 -mfpu=neon -mfloat-abi=softfp -fomit-frame-pointer -DTIME -DHZ=166 -DREG=register dhry_1.c dhry_2.c -o gcc_dry2regdhry_1.c:31: warning: conflicting types for built-in function ‘malloc’dhry_1.c: In function ‘main’:dhry_1.c:98: warning: incompatible implicit declaration of built-in function ‘strcpy’</pre></blockquote> = Running the benchmark and gathering results = The make command outputs 2 files named '''gcc_dry2''' and '''gcc_dry2reg'''. The author of this version decided to create 2 dhrystone executables . One with register variables, and one without. Either one will work for the benchmark so, feel free to test it out. <font style="font-size:110%><b>1. Run the executable by typing ''./gcc_dry2''</b></font>
== Project News =And... =