double remquo ( double x, double y, int *quo)
{
int iclx,icly; /* classify results of x,y */
int32_t iquo; /* low 32 bits of integral quotient */
int32_t iscx, iscy, idiff; /* logb values and difference */
int i; /* loop variable */
double absy,x1,y1,z; /* local floating-point variables */
double rslt;
fenv_t OldEnv;
hexdouble OldEnvironment;
int newexc;
FEGETENVD ( OldEnvironment.d );
FESETENVD ( 0.0 );
__NOOP;
__NOOP;
OldEnv = OldEnvironment.i.lo;
*quo = 0; /* initialize quotient result */
iclx = ___fpclassifyd(x);
icly = ___fpclassifyd(y);
if (likely((iclx & icly) >= FP_NORMAL)) { /* x,y both nonzero finite case */
x1 = __FABS(x); /* work with absolute values */
absy = __FABS(y);
iquo = 0; /* zero local quotient */
iscx = (int32_t) __logb(x1); /* get binary exponents */
iscy = (int32_t) __logb(absy);
idiff = iscx - iscy; /* exponent difference */
if (idiff >= 0) { /* exponent of x1 >= exponent of y1 */
if (idiff != 0) { /* exponent of x1 > exponent of y1 */
y1 = __scalbn(absy,-iscy); /* scale |y| to unit binade */
x1 = __scalbn(x1,-iscx); /* ditto for |x| */
for (i = idiff; i != 0; i--) { /* begin remainder loop */
if ((z = x1 - y1) >= 0) { /* nonzero remainder step result */
x1 = z; /* update remainder (x1) */
iquo += 1; /* increment quotient */
}
iquo += iquo; /* shift quotient left one bit */
x1 += x1; /* shift (double) remainder */
} /* end of remainder loop */
x1 = __scalbn(x1,iscy); /* scale remainder to binade of |y| */
} /* remainder has exponent <= exponent of y */
if (x1 >= absy) { /* last remainder step */
x1 -= absy;
iquo +=1;
} /* end of last remainder step */
} /* remainder (x1) has smaller exponent than y */
if (likely( x1 < HugeHalved.d ))
z = x1 + x1; /* double remainder, without overflow */
else
z = Huge.d;
if ((z > absy) || ((z == absy) && ((iquo & 1) != 0))) {
x1 -= absy; /* final remainder correction */
iquo += 1;
}
if (x < 0.0)
x1 = -x1; /* remainder if x is negative */
iquo &= 0x0000007f; /* retain low 7 bits of integer quotient */
if ((___signbitd(x) ^ ___signbitd(y)) != 0) /* take care of sign of quotient */
iquo = -iquo;
*quo = iquo; /* deliver quotient result */
rslt = x1;
goto ret;
} /* end of x,y both nonzero finite case */
else if ((iclx <= FP_QNAN) || (icly <= FP_QNAN)) {
rslt = x+y; /* at least one NaN operand */
goto ret;
}
else if ((iclx == FP_INFINITE)||(icly == FP_ZERO)) { /* invalid result */
rslt = nan(REM_NAN);
OldEnvironment.i.lo |= SET_INVALID;
FESETENVD_GRP( OldEnvironment.d );
goto ret;
}
else /* trivial cases (finite REM infinite */
rslt = x; /* or zero REM nonzero) with *quo = 0 */
ret:
FEGETENVD_GRP( OldEnvironment.d );
newexc = OldEnvironment.i.lo & FE_ALL_EXCEPT;
OldEnvironment.i.lo = OldEnv;
if ((newexc & FE_INVALID) != 0)
OldEnvironment.i.lo |= SET_INVALID;
OldEnvironment.i.lo |= newexc & ( FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | FE_OVERFLOW );
FESETENVD_GRP( OldEnvironment.d );
return rslt;
}
Err mathlib_logb(UInt16 refnum, double x, double *result) {
#pragma unused(refnum)
*result = __logb(x);
return mlErrNone;
}
long double logbl(long double x) {
return ( (long double)__logb((double)x) );
}
