When do you use fp:strict as opposed to fp:precise? Is it better to use the former if I want "more precise" calculations and avoid rounding errors? What is the heuristic behind using either?
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The standard IEEE 754 specifies a method for floating point calculations and storage of floating point values in memory.
Using fp:strict means that all the rules of IEEE 754 are respected. fp:strict is used to sustain bitwise compatibility between different compilers and platforms.
fp:precise weakens some of the rules, however it warranties that the precision of the calculations will not be lost.
fp:fast allows compiler specific optimizations and transformations of expressions containing floating point calculation. It is the fastest methods but the results will differ between different compilers and platforms.
Sergey K.
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1Do you know where I can learn about the rules that the :precise relaxes? – unj2 Sep 20 '12 at 18:59
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@unj2 https://learn.microsoft.com/en-us/cpp/build/reference/fp-specify-floating-point-behavior?view=msvc-170 – ScienceDiscoverer Jul 26 '22 at 10:56