safe_scale

eve::safe_scale = functor<safe_scale_t>

inlineconstexpr

Header file

#include <eve/module/core.hpp>

Callable Signatures

namespace eve
{
   // Regular overload
   constexpr auto safe_scale(floating_value auto x)                 noexcept; // 1
 
   // Lanes masking
   constexpr auto safe_scale[conditional_expr auto c](value auto x) noexcept; // 2
   constexpr auto safe_scale[logical_value auto m](value auto x)    noexcept; // 2
 
   // Semantic options
   constexpr auto safe_scale[pedantic](value auto x)                noexcept; // 3
}

Parameters

• x: value.
• c: Conditional expression masking the operation.
• m: Logical value masking the operation.

Return value

1. provide a value s such that |x|/s, is much above the underflow threshold and much below the overflow threshold (so that, for example, we can safely square it); (return maxflint for 0); moreover it is an integer power of 2 (in order to avoid rounding errors when multiplying or dividing by it).
2. The operation is performed conditionnaly.
3. same as 1. but return 1 for 0

External references

• HAL: On various ways to split a floating-point number

Example