This is not much of a tip, just a posting of benchmark result to compare integer and floating point arithmetic timing. All the integer and floating point types used in Benchmark are 64bit. Timing is based on looping 100 million times. Clarification:
SmallDouble refers to small values (10-10000) stored in
double, not referring to the type size. Big integer and double value range from 10,000 to 1000,000, if they are any bigger, there would be overflow in 64bit integer.
- Processor: Intel i7-6700 CPU @ 3.40GHz, 3400 Mhz, 4 Cores, 8 Logical Processors
- RAM: 16 GB
- Graphics Card: NVIDIA GeForce GTX 1060 6GB
CSharp x64 Benchmark
Note: x86-32 executable typically has worse integer performance than floating point (not shown here). You can build as x86-32 executable and run it to see for yourself.
Multiplication and Division Benchmark ===================================== MulBigDouble RunTime:00:00.186 MulBigInt RunTime:00:00.157 DivBigDouble RunTime:00:00.160 DivBigInt RunTime:00:00.776 MulSmallDouble RunTime:00:00.192 MulSmallInt RunTime:00:00.191 DivSmallDouble RunTime:00:00.205 DivSmallInt RunTime:00:00.933 Addition and Subtraction Benchmark ================================== AddBigDouble RunTime:00:00.167 AddBigInt RunTime:00:00.154 SubBigDouble RunTime:00:00.151 SubBigInt RunTime:00:00.152 AddSmallDouble RunTime:00:00.204 AddSmallInt RunTime:00:00.187 SubSmallDouble RunTime:00:00.186 SubSmallInt RunTime:00:00.218
C++ x64 Benchmark
Multiplication and Division Benchmark ===================================== MulBigDouble: 57ms MulBigInt: 49ms DivBigDouble: 96ms DivBigInt: 636ms MulSmallDouble: 60ms MulSmallInt: 68ms DivSmallDouble: 118ms DivSmallInt: 823ms Addition and Subtraction Benchmark ================================== AddBigDouble: 57ms AddBigInt: 49ms SubBigDouble: 64ms SubBigInt: 49ms AddSmallDouble: 69ms AddSmallInt: 59ms SubSmallDouble: 63ms SubSmallInt: 59ms
Most of the time, integer performance is on par with floating point, with exception of division.
The performance of floating point arithmetic has caught up with the integer in the last 15 years. This very much removes the requirement to have our own custom fixed point type to wring last drop of performance out of processor. For those who are not familiar, fixed point is arithmetic type which is like floating point except its decimal point is fixed, does not move, hence its name. The main difference is fixed point arithmetic is executed on the integer unit, not on floating point unit. Fixed point type was relevant during the period where integer perf was crown over floating point. Source code download consists of the CSharp and C++ version of the same benchmark.
Any suggestions on how to improve the nature of benchmark or constructive criticism on what I have been doing wrong, are all welcome.
Source code is hosted at Github.