Issue #1580: use short float repr where possible. - incorporate and adapt David Gay's dtoa and strtod into the Python core - on platforms where we can use Gay's code (almost all!), repr(float) is based on the shortest sequence of decimal digits that rounds correctly. - add sys.float_repr_style attribute to indicate whether we're using Gay's code or not - add autoconf magic to detect and enable SSE2 instructions on x86/gcc - slight change to repr and str: repr switches to exponential notation at 1e16 instead of 1e17, str switches at 1e11 instead of 1e12

/* Cross platform case insensitive string compare functions
 */

#include "Python.h"

int
PyOS_mystrnicmp(const char *s1, const char *s2, Py_ssize_t size)
{
	if (size == 0)
		return 0;
	while ((--size > 0) &&
	       (tolower((unsigned)*s1) == tolower((unsigned)*s2))) {
		if (!*s1++ || !*s2++)
			break;
	}
	return tolower((unsigned)*s1) - tolower((unsigned)*s2);
}

int
PyOS_mystricmp(const char *s1, const char *s2)
{
	while (*s1 && (tolower((unsigned)*s1++) == tolower((unsigned)*s2++))) {
		;
	}
	return (tolower((unsigned)*s1) - tolower((unsigned)*s2));
}