[FIXED] How to detect the non-spurious FE_INEXACT?

Issue

C11, F.10 allows spurious ‘‘inexact’’ floating-point exception to be raised.

C11, F.10 Mathematics <math.h>, 9 (emphasis added):

Whether or when library functions raise an undeserved ‘‘underflow’’ floating-point exception is unspecified.³⁷²⁾ Otherwise, as implied by F.8.6, the <math.h> functions do not raise spurious floating-point exceptions (detectable by the user), other than the ‘‘inexact’’ floating-point exception.

If <math.h> functions may raise spurious FE_INEXACT, then how to detect the non-spurious FE_INEXACT?

Solution

Answer from Fred J. Tydeman (Vice-chair of PL22.11 (ANSI "C")):

Q: Does it mean that the C Standard provides no reliable way to detect the non-spurious FE_INEXACT?

A: Correct.

Answered By - pmor

Answer Checked By - Robin (PHPFixing Admin)