ldexp.c File Reference

#include <precomp.h>

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Functions
double	ldexp (double value, int exp)

Function Documentation

ldexp()

double ldexp	(	double	value,
		int	exp
	)

Definition at line 12 of file ldexp.c.

{
#ifdef __GNUC__
    register double result;
#endif
 
    /* Check for value correctness
     * and set errno if required
     */
    if (_isnan(value))
    {
        errno = EDOM;
    }
 
#ifdef __GNUC__
    asm ("fscale"
         : "=t" (result)
         : "0" (value), "u" ((double)exp)
         : "1");
    return result;
#else /* !__GNUC__ */
    __asm
    {
        fild exp
        fld value
        fscale
        fstp st(1)
    }
 
    /* "fstp st(1)" has copied st(0) to st(1), then popped the FPU stack,
     * so that the value is again in st(0) now. Effectively, we have reduced
     * the FPU stack by one element while preserving st(0).
     * st(0) is also the register used for returning a double value. */
#endif /* !__GNUC__ */
}