"[...] without any loss of accuracy."
Fortran programs are notorious for producing different results from the same data when you change something.
In the "old days" different computer models had different precisions for floating point. Even with the same number of bits for mantissa and exponent there could be different ways for the hardware to perform a single operation.
The same applies to the software - change the order in which parts of a calculation are performed and the intermediate rounding can change the end result.
Do "industry standards" eliminate those problems - especially for programs that may have originated before such standards were set?
The first "live" program I wrote was a floating point emulator to test the results of a prototype mainframe. That taught me that unless you copied the hardware microcode ogic exactly then the results did not always match in marginal conditions.
On an earlier model - a customer did designs for turbine blades. As they were not done very often there was a precautionary practice of repeating the last data set as a benchmark. One day the results didn't match and it was assumed there was a subtle problem with the computer. To everyone's surprise it was the previous results that had been wrong.
Biting the hand that feeds IT
