Some tests are performed on many different processors from 8086 to modern CPU's. The initial purpose of the tests is the evaluation of my own compiler. But it is only integer tests. Here simple floating point tests presented. They are very simple and may be performed even on many programmable calculators. They calculates the area under half the period of the sine function by using rectangle method, the simplest method of integration.

MS DOS version of my own compiler implements double precision arithmetic on 8087 FPU unit. It also used.

On some systems number of intervals (N) reduced to 10⁶ - 10¹ and the time is multiplied by 10⁷ /  N. Nubmer of signs after decimal point may be greater than time measurement accuracy.

For calculations with single precision (Real*4) N = 10⁷ is too large and the error of the result is significant (2.023 instead of 2.0), but here the time is determined, not the area.

Sine function calculated by FPU/library call and sum of Maclaurin series. Floating point arithmetic are performed by FPU/library calls and self-written software implementation (possible inefficient).

GCC or BCC compilers are used. On some old compters built-in Basic interpreter are used. It is incorrect to compare the speed of compiled and interpreted code. On new machines the difference can be hundreds of times, on old machines it is much less - from two to five times. This is true for floating point calculations only, for integer calculations the difference are much more.

Thanks to the Yandex Museum for the opportunity to use some old computers - IBM 5150, Apple//e, Sinclair ZX81 and some others.

Source code for first two columns (FPU/Lib and Soft-sin):

Most of the results were obtained on real machines, some were also obtained on emulators. Some of them are correct, others are not: