[php-src] Issue #8314: EXP(N) != M_E ** N

Issue: https://github.com/php/php-src/issues/8314 Comment Author: cmb69 Floating point values have a limited precision. Hence a value might not have the same string representation after any processing. That also includes writing a floating point value in your script and directly printing it without any mathematical operations. If you would like to know more about "floats" and what IEEE 754 is, read this: http://www.floating-point-gui.de/ Thank you for your interest in PHP.