/*ARGSUSED*/
int
dbl_fsqrt(dbl_floating_point *srcptr, dbl_floating_point *dstptr,
unsigned int *status)
{
register unsigned int srcp1, srcp2, resultp1, resultp2;
register unsigned int newbitp1, newbitp2, sump1, sump2;
register int src_exponent;
register int guardbit = false, even_exponent;
Dbl_copyfromptr(srcptr,srcp1,srcp2);
/*
* check source operand for NaN or infinity
*/
if ((src_exponent = Dbl_exponent(srcp1)) == DBL_INFINITY_EXPONENT) {
/*
* is signaling NaN?
*/
if (Dbl_isone_signaling(srcp1)) {
/* trap if INVALIDTRAP enabled */
if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
/* make NaN quiet */
Set_invalidflag();
Dbl_set_quiet(srcp1);
}
/*
* Return quiet NaN or positive infinity.
* Fall thru to negative test if negative infinity.
*/
if (Dbl_iszero_sign(srcp1) ||
Dbl_isnotzero_mantissa(srcp1,srcp2)) {
Dbl_copytoptr(srcp1,srcp2,dstptr);
return(NOEXCEPTION);
}
}
/*
* check for zero source operand
*/
if (Dbl_iszero_exponentmantissa(srcp1,srcp2)) {
Dbl_copytoptr(srcp1,srcp2,dstptr);
return(NOEXCEPTION);
}
/*
* check for negative source operand
*/
if (Dbl_isone_sign(srcp1)) {
/* trap if INVALIDTRAP enabled */
if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
/* make NaN quiet */
Set_invalidflag();
Dbl_makequietnan(srcp1,srcp2);
Dbl_copytoptr(srcp1,srcp2,dstptr);
return(NOEXCEPTION);
}
/*
* Generate result
*/
if (src_exponent > 0) {
even_exponent = Dbl_hidden(srcp1);
Dbl_clear_signexponent_set_hidden(srcp1);
}
else {
/* normalize operand */
Dbl_clear_signexponent(srcp1);
src_exponent++;
Dbl_normalize(srcp1,srcp2,src_exponent);
even_exponent = src_exponent & 1;
}
if (even_exponent) {
/* exponent is even */
/* Add comment here. Explain why odd exponent needs correction */
Dbl_leftshiftby1(srcp1,srcp2);
}
/*
* Add comment here. Explain following algorithm.
*
* Trust me, it works.
*
*/
Dbl_setzero(resultp1,resultp2);
Dbl_allp1(newbitp1) = 1 << (DBL_P - 32);
Dbl_setzero_mantissap2(newbitp2);
while (Dbl_isnotzero(newbitp1,newbitp2) && Dbl_isnotzero(srcp1,srcp2)) {
Dbl_addition(resultp1,resultp2,newbitp1,newbitp2,sump1,sump2);
if(Dbl_isnotgreaterthan(sump1,sump2,srcp1,srcp2)) {
Dbl_leftshiftby1(newbitp1,newbitp2);
/* update result */
Dbl_addition(resultp1,resultp2,newbitp1,newbitp2,
resultp1,resultp2);
Dbl_subtract(srcp1,srcp2,sump1,sump2,srcp1,srcp2);
Dbl_rightshiftby2(newbitp1,newbitp2);
}
else {
Dbl_rightshiftby1(newbitp1,newbitp2);
}
Dbl_leftshiftby1(srcp1,srcp2);
}
/* correct exponent for pre-shift */
if (even_exponent) {
Dbl_rightshiftby1(resultp1,resultp2);
}
/* check for inexact */
if (Dbl_isnotzero(srcp1,srcp2)) {
if (!even_exponent && Dbl_islessthan(resultp1,resultp2,srcp1,srcp2)) {
Dbl_increment(resultp1,resultp2);
}
guardbit = Dbl_lowmantissap2(resultp2);
Dbl_rightshiftby1(resultp1,resultp2);
/* now round result */
switch (Rounding_mode()) {
case ROUNDPLUS:
Dbl_increment(resultp1,resultp2);
break;
case ROUNDNEAREST:
/* stickybit is always true, so guardbit
* is enough to determine rounding */
if (guardbit) {
Dbl_increment(resultp1,resultp2);
}
break;
}
/* increment result exponent by 1 if mantissa overflowed */
if (Dbl_isone_hiddenoverflow(resultp1)) src_exponent+=2;
if (Is_inexacttrap_enabled()) {
Dbl_set_exponent(resultp1,
((src_exponent-DBL_BIAS)>>1)+DBL_BIAS);
Dbl_copytoptr(resultp1,resultp2,dstptr);
return(INEXACTEXCEPTION);
}
else Set_inexactflag();
}
/*
* Double Precision Floating-point Remainder
*/
int
dbl_frem(dbl_floating_point *srcptr1, dbl_floating_point *srcptr2,
dbl_floating_point *dstptr, unsigned int *status)
{
register unsigned int opnd1p1, opnd1p2, opnd2p1, opnd2p2;
register unsigned int resultp1, resultp2;
register int opnd1_exponent, opnd2_exponent, dest_exponent, stepcount;
register int roundup = false;
Dbl_copyfromptr(srcptr1,opnd1p1,opnd1p2);
Dbl_copyfromptr(srcptr2,opnd2p1,opnd2p2);
/*
* check first operand for NaN's or infinity
*/
if ((opnd1_exponent = Dbl_exponent(opnd1p1)) == DBL_INFINITY_EXPONENT) {
if (Dbl_iszero_mantissa(opnd1p1,opnd1p2)) {
if (Dbl_isnotnan(opnd2p1,opnd2p2)) {
/* invalid since first operand is infinity */
if (Is_invalidtrap_enabled())
return(INVALIDEXCEPTION);
Set_invalidflag();
Dbl_makequietnan(resultp1,resultp2);
Dbl_copytoptr(resultp1,resultp2,dstptr);
return(NOEXCEPTION);
}
}
else {
/*
* is NaN; signaling or quiet?
*/
if (Dbl_isone_signaling(opnd1p1)) {
/* trap if INVALIDTRAP enabled */
if (Is_invalidtrap_enabled())
return(INVALIDEXCEPTION);
/* make NaN quiet */
Set_invalidflag();
Dbl_set_quiet(opnd1p1);
}
/*
* is second operand a signaling NaN?
*/
else if (Dbl_is_signalingnan(opnd2p1)) {
/* trap if INVALIDTRAP enabled */
if (Is_invalidtrap_enabled())
return(INVALIDEXCEPTION);
/* make NaN quiet */
Set_invalidflag();
Dbl_set_quiet(opnd2p1);
Dbl_copytoptr(opnd2p1,opnd2p2,dstptr);
return(NOEXCEPTION);
}
/*
* return quiet NaN
*/
Dbl_copytoptr(opnd1p1,opnd1p2,dstptr);
return(NOEXCEPTION);
}
}
/*
* check second operand for NaN's or infinity
*/
if ((opnd2_exponent = Dbl_exponent(opnd2p1)) == DBL_INFINITY_EXPONENT) {
if (Dbl_iszero_mantissa(opnd2p1,opnd2p2)) {
/*
* return first operand
*/
Dbl_copytoptr(opnd1p1,opnd1p2,dstptr);
return(NOEXCEPTION);
}
/*
* is NaN; signaling or quiet?
*/
if (Dbl_isone_signaling(opnd2p1)) {
/* trap if INVALIDTRAP enabled */
if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
/* make NaN quiet */
Set_invalidflag();
Dbl_set_quiet(opnd2p1);
}
/*
* return quiet NaN
*/
Dbl_copytoptr(opnd2p1,opnd2p2,dstptr);
return(NOEXCEPTION);
}
/*
* check second operand for zero
*/
if (Dbl_iszero_exponentmantissa(opnd2p1,opnd2p2)) {
/* invalid since second operand is zero */
if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
Set_invalidflag();
Dbl_makequietnan(resultp1,resultp2);
Dbl_copytoptr(resultp1,resultp2,dstptr);
return(NOEXCEPTION);
}
/*
* get sign of result
*/
resultp1 = opnd1p1;
/*
* check for denormalized operands
*/
if (opnd1_exponent == 0) {
/* check for zero */
if (Dbl_iszero_mantissa(opnd1p1,opnd1p2)) {
Dbl_copytoptr(opnd1p1,opnd1p2,dstptr);
return(NOEXCEPTION);
}
/* normalize, then continue */
opnd1_exponent = 1;
Dbl_normalize(opnd1p1,opnd1p2,opnd1_exponent);
}
else {
Dbl_clear_signexponent_set_hidden(opnd1p1);
}
if (opnd2_exponent == 0) {
/* normalize, then continue */
opnd2_exponent = 1;
Dbl_normalize(opnd2p1,opnd2p2,opnd2_exponent);
}
else {
Dbl_clear_signexponent_set_hidden(opnd2p1);
}
/* find result exponent and divide step loop count */
dest_exponent = opnd2_exponent - 1;
stepcount = opnd1_exponent - opnd2_exponent;
/*
* check for opnd1/opnd2 < 1
*/
if (stepcount < 0) {
/*
* check for opnd1/opnd2 > 1/2
*
* In this case n will round to 1, so
* r = opnd1 - opnd2
*/
if (stepcount == -1 &&
Dbl_isgreaterthan(opnd1p1,opnd1p2,opnd2p1,opnd2p2)) {
/* set sign */
Dbl_allp1(resultp1) = ~Dbl_allp1(resultp1);
/* align opnd2 with opnd1 */
Dbl_leftshiftby1(opnd2p1,opnd2p2);
Dbl_subtract(opnd2p1,opnd2p2,opnd1p1,opnd1p2,
opnd2p1,opnd2p2);
/* now normalize */
while (Dbl_iszero_hidden(opnd2p1)) {
Dbl_leftshiftby1(opnd2p1,opnd2p2);
dest_exponent--;
}
Dbl_set_exponentmantissa(resultp1,resultp2,opnd2p1,opnd2p2);
goto testforunderflow;
}
/*
* opnd1/opnd2 <= 1/2
*
* In this case n will round to zero, so
* r = opnd1
*/
Dbl_set_exponentmantissa(resultp1,resultp2,opnd1p1,opnd1p2);
dest_exponent = opnd1_exponent;
goto testforunderflow;
}
/*
* Generate result
*
* Do iterative subtract until remainder is less than operand 2.
*/
while (stepcount-- > 0 && (Dbl_allp1(opnd1p1) || Dbl_allp2(opnd1p2))) {
if (Dbl_isnotlessthan(opnd1p1,opnd1p2,opnd2p1,opnd2p2)) {
Dbl_subtract(opnd1p1,opnd1p2,opnd2p1,opnd2p2,opnd1p1,opnd1p2);
}
Dbl_leftshiftby1(opnd1p1,opnd1p2);
}
/*
* Do last subtract, then determine which way to round if remainder
* is exactly 1/2 of opnd2
*/
if (Dbl_isnotlessthan(opnd1p1,opnd1p2,opnd2p1,opnd2p2)) {
Dbl_subtract(opnd1p1,opnd1p2,opnd2p1,opnd2p2,opnd1p1,opnd1p2);
roundup = true;
}
if (stepcount > 0 || Dbl_iszero(opnd1p1,opnd1p2)) {
/* division is exact, remainder is zero */
Dbl_setzero_exponentmantissa(resultp1,resultp2);
Dbl_copytoptr(resultp1,resultp2,dstptr);
return(NOEXCEPTION);
}
/*
* Check for cases where opnd1/opnd2 < n
*
* In this case the result's sign will be opposite that of
* opnd1. The mantissa also needs some correction.
*/
Dbl_leftshiftby1(opnd1p1,opnd1p2);
if (Dbl_isgreaterthan(opnd1p1,opnd1p2,opnd2p1,opnd2p2)) {
Dbl_invert_sign(resultp1);
Dbl_leftshiftby1(opnd2p1,opnd2p2);
Dbl_subtract(opnd2p1,opnd2p2,opnd1p1,opnd1p2,opnd1p1,opnd1p2);
}
/* check for remainder being exactly 1/2 of opnd2 */
else if (Dbl_isequal(opnd1p1,opnd1p2,opnd2p1,opnd2p2) && roundup) {
Dbl_invert_sign(resultp1);
}
/* normalize result's mantissa */
while (Dbl_iszero_hidden(opnd1p1)) {
dest_exponent--;
Dbl_leftshiftby1(opnd1p1,opnd1p2);
}
Dbl_set_exponentmantissa(resultp1,resultp2,opnd1p1,opnd1p2);
/*
* Test for underflow
*/
testforunderflow:
if (dest_exponent <= 0) {
/* trap if UNDERFLOWTRAP enabled */
if (Is_underflowtrap_enabled()) {
/*
* Adjust bias of result
*/
Dbl_setwrapped_exponent(resultp1,dest_exponent,unfl);
/* frem is always exact */
Dbl_copytoptr(resultp1,resultp2,dstptr);
return(UNDERFLOWEXCEPTION);
}
/*
* denormalize result or set to signed zero
*/
if (dest_exponent >= (1 - DBL_P)) {
Dbl_rightshift_exponentmantissa(resultp1,resultp2,
1-dest_exponent);
}
else {
Dbl_setzero_exponentmantissa(resultp1,resultp2);
}
}
else Dbl_set_exponent(resultp1,dest_exponent);
Dbl_copytoptr(resultp1,resultp2,dstptr);
return(NOEXCEPTION);
}
int
dbl_fdiv (dbl_floating_point * srcptr1, dbl_floating_point * srcptr2,
dbl_floating_point * dstptr, unsigned int *status)
{
register unsigned int opnd1p1, opnd1p2, opnd2p1, opnd2p2;
register unsigned int opnd3p1, opnd3p2, resultp1, resultp2;
register int dest_exponent, count;
register boolean inexact = FALSE, guardbit = FALSE, stickybit = FALSE;
boolean is_tiny;
Dbl_copyfromptr(srcptr1,opnd1p1,opnd1p2);
Dbl_copyfromptr(srcptr2,opnd2p1,opnd2p2);
/*
* set sign bit of result
*/
if (Dbl_sign(opnd1p1) ^ Dbl_sign(opnd2p1))
Dbl_setnegativezerop1(resultp1);
else Dbl_setzerop1(resultp1);
/*
* check first operand for NaN's or infinity
*/
if (Dbl_isinfinity_exponent(opnd1p1)) {
if (Dbl_iszero_mantissa(opnd1p1,opnd1p2)) {
if (Dbl_isnotnan(opnd2p1,opnd2p2)) {
if (Dbl_isinfinity(opnd2p1,opnd2p2)) {
/*
* invalid since both operands
* are infinity
*/
if (Is_invalidtrap_enabled())
return(INVALIDEXCEPTION);
Set_invalidflag();
Dbl_makequietnan(resultp1,resultp2);
Dbl_copytoptr(resultp1,resultp2,dstptr);
return(NOEXCEPTION);
}
/*
* return infinity
*/
Dbl_setinfinity_exponentmantissa(resultp1,resultp2);
Dbl_copytoptr(resultp1,resultp2,dstptr);
return(NOEXCEPTION);
}
}
else {
/*
* is NaN; signaling or quiet?
*/
if (Dbl_isone_signaling(opnd1p1)) {
/* trap if INVALIDTRAP enabled */
if (Is_invalidtrap_enabled())
return(INVALIDEXCEPTION);
/* make NaN quiet */
Set_invalidflag();
Dbl_set_quiet(opnd1p1);
}
/*
* is second operand a signaling NaN?
*/
else if (Dbl_is_signalingnan(opnd2p1)) {
/* trap if INVALIDTRAP enabled */
if (Is_invalidtrap_enabled())
return(INVALIDEXCEPTION);
/* make NaN quiet */
Set_invalidflag();
Dbl_set_quiet(opnd2p1);
Dbl_copytoptr(opnd2p1,opnd2p2,dstptr);
return(NOEXCEPTION);
}
/*
* return quiet NaN
*/
Dbl_copytoptr(opnd1p1,opnd1p2,dstptr);
return(NOEXCEPTION);
}
}
/*
* check second operand for NaN's or infinity
*/
if (Dbl_isinfinity_exponent(opnd2p1)) {
if (Dbl_iszero_mantissa(opnd2p1,opnd2p2)) {
/*
* return zero
*/
Dbl_setzero_exponentmantissa(resultp1,resultp2);
Dbl_copytoptr(resultp1,resultp2,dstptr);
return(NOEXCEPTION);
}
/*
* is NaN; signaling or quiet?
*/
if (Dbl_isone_signaling(opnd2p1)) {
/* trap if INVALIDTRAP enabled */
if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
/* make NaN quiet */
Set_invalidflag();
Dbl_set_quiet(opnd2p1);
}
/*
* return quiet NaN
*/
Dbl_copytoptr(opnd2p1,opnd2p2,dstptr);
return(NOEXCEPTION);
}
/*
* check for division by zero
*/
if (Dbl_iszero_exponentmantissa(opnd2p1,opnd2p2)) {
if (Dbl_iszero_exponentmantissa(opnd1p1,opnd1p2)) {
/* invalid since both operands are zero */
if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
Set_invalidflag();
Dbl_makequietnan(resultp1,resultp2);
Dbl_copytoptr(resultp1,resultp2,dstptr);
return(NOEXCEPTION);
}
if (Is_divisionbyzerotrap_enabled())
return(DIVISIONBYZEROEXCEPTION);
Set_divisionbyzeroflag();
Dbl_setinfinity_exponentmantissa(resultp1,resultp2);
Dbl_copytoptr(resultp1,resultp2,dstptr);
return(NOEXCEPTION);
}
/*
* Generate exponent
*/
dest_exponent = Dbl_exponent(opnd1p1) - Dbl_exponent(opnd2p1) + DBL_BIAS;
/*
* Generate mantissa
*/
if (Dbl_isnotzero_exponent(opnd1p1)) {
/* set hidden bit */
Dbl_clear_signexponent_set_hidden(opnd1p1);
}
else {
/* check for zero */
if (Dbl_iszero_mantissa(opnd1p1,opnd1p2)) {
Dbl_setzero_exponentmantissa(resultp1,resultp2);
Dbl_copytoptr(resultp1,resultp2,dstptr);
return(NOEXCEPTION);
}
/* is denormalized, want to normalize */
Dbl_clear_signexponent(opnd1p1);
Dbl_leftshiftby1(opnd1p1,opnd1p2);
Dbl_normalize(opnd1p1,opnd1p2,dest_exponent);
}
/* opnd2 needs to have hidden bit set with msb in hidden bit */
if (Dbl_isnotzero_exponent(opnd2p1)) {
Dbl_clear_signexponent_set_hidden(opnd2p1);
}
else {
/* is denormalized; want to normalize */
Dbl_clear_signexponent(opnd2p1);
Dbl_leftshiftby1(opnd2p1,opnd2p2);
while (Dbl_iszero_hiddenhigh7mantissa(opnd2p1)) {
dest_exponent+=8;
Dbl_leftshiftby8(opnd2p1,opnd2p2);
}
if (Dbl_iszero_hiddenhigh3mantissa(opnd2p1)) {
dest_exponent+=4;
Dbl_leftshiftby4(opnd2p1,opnd2p2);
}
while (Dbl_iszero_hidden(opnd2p1)) {
dest_exponent++;
Dbl_leftshiftby1(opnd2p1,opnd2p2);
}
}
/* Divide the source mantissas */
/*
* A non-restoring divide algorithm is used.
*/
Twoword_subtract(opnd1p1,opnd1p2,opnd2p1,opnd2p2);
Dbl_setzero(opnd3p1,opnd3p2);
for (count=1; count <= DBL_P && (opnd1p1 || opnd1p2); count++) {
Dbl_leftshiftby1(opnd1p1,opnd1p2);
Dbl_leftshiftby1(opnd3p1,opnd3p2);
if (Dbl_iszero_sign(opnd1p1)) {
Dbl_setone_lowmantissap2(opnd3p2);
Twoword_subtract(opnd1p1,opnd1p2,opnd2p1,opnd2p2);
}
else {
Twoword_add(opnd1p1, opnd1p2, opnd2p1, opnd2p2);
}
}
if (count <= DBL_P) {
Dbl_leftshiftby1(opnd3p1,opnd3p2);
Dbl_setone_lowmantissap2(opnd3p2);
Dbl_leftshift(opnd3p1,opnd3p2,(DBL_P-count));
if (Dbl_iszero_hidden(opnd3p1)) {
Dbl_leftshiftby1(opnd3p1,opnd3p2);
dest_exponent--;
}
}
else {
if (Dbl_iszero_hidden(opnd3p1)) {
/* need to get one more bit of result */
Dbl_leftshiftby1(opnd1p1,opnd1p2);
Dbl_leftshiftby1(opnd3p1,opnd3p2);
if (Dbl_iszero_sign(opnd1p1)) {
Dbl_setone_lowmantissap2(opnd3p2);
Twoword_subtract(opnd1p1,opnd1p2,opnd2p1,opnd2p2);
}
else {
Twoword_add(opnd1p1,opnd1p2,opnd2p1,opnd2p2);
}
dest_exponent--;
}
if (Dbl_iszero_sign(opnd1p1)) guardbit = TRUE;
stickybit = Dbl_allp1(opnd1p1) || Dbl_allp2(opnd1p2);
}
inexact = guardbit | stickybit;
/*
* round result
*/
if (inexact && (dest_exponent > 0 || Is_underflowtrap_enabled())) {
Dbl_clear_signexponent(opnd3p1);
switch (Rounding_mode()) {
case ROUNDPLUS:
if (Dbl_iszero_sign(resultp1))
Dbl_increment(opnd3p1,opnd3p2);
break;
case ROUNDMINUS:
if (Dbl_isone_sign(resultp1))
Dbl_increment(opnd3p1,opnd3p2);
break;
case ROUNDNEAREST:
if (guardbit && (stickybit ||
Dbl_isone_lowmantissap2(opnd3p2))) {
Dbl_increment(opnd3p1,opnd3p2);
}
}
if (Dbl_isone_hidden(opnd3p1)) dest_exponent++;
}
Dbl_set_mantissa(resultp1,resultp2,opnd3p1,opnd3p2);
/*
* Test for overflow
*/
if (dest_exponent >= DBL_INFINITY_EXPONENT) {
/* trap if OVERFLOWTRAP enabled */
if (Is_overflowtrap_enabled()) {
/*
* Adjust bias of result
*/
Dbl_setwrapped_exponent(resultp1,dest_exponent,ovfl);
Dbl_copytoptr(resultp1,resultp2,dstptr);
if (inexact)
if (Is_inexacttrap_enabled())
return(OVERFLOWEXCEPTION | INEXACTEXCEPTION);
else Set_inexactflag();
return(OVERFLOWEXCEPTION);
}
Set_overflowflag();
/* set result to infinity or largest number */
Dbl_setoverflow(resultp1,resultp2);
inexact = TRUE;
}
/*
* Test for underflow
*/
else if (dest_exponent <= 0) {
/* trap if UNDERFLOWTRAP enabled */
if (Is_underflowtrap_enabled()) {
/*
* Adjust bias of result
*/
Dbl_setwrapped_exponent(resultp1,dest_exponent,unfl);
Dbl_copytoptr(resultp1,resultp2,dstptr);
if (inexact)
if (Is_inexacttrap_enabled())
return(UNDERFLOWEXCEPTION | INEXACTEXCEPTION);
else Set_inexactflag();
return(UNDERFLOWEXCEPTION);
}
/* Determine if should set underflow flag */
is_tiny = TRUE;
if (dest_exponent == 0 && inexact) {
switch (Rounding_mode()) {
case ROUNDPLUS:
if (Dbl_iszero_sign(resultp1)) {
Dbl_increment(opnd3p1,opnd3p2);
if (Dbl_isone_hiddenoverflow(opnd3p1))
is_tiny = FALSE;
Dbl_decrement(opnd3p1,opnd3p2);
}
break;
case ROUNDMINUS:
if (Dbl_isone_sign(resultp1)) {
Dbl_increment(opnd3p1,opnd3p2);
if (Dbl_isone_hiddenoverflow(opnd3p1))
is_tiny = FALSE;
Dbl_decrement(opnd3p1,opnd3p2);
}
break;
case ROUNDNEAREST:
if (guardbit && (stickybit ||
Dbl_isone_lowmantissap2(opnd3p2))) {
Dbl_increment(opnd3p1,opnd3p2);
if (Dbl_isone_hiddenoverflow(opnd3p1))
is_tiny = FALSE;
Dbl_decrement(opnd3p1,opnd3p2);
}
break;
}
}
/*
* denormalize result or set to signed zero
*/
stickybit = inexact;
Dbl_denormalize(opnd3p1,opnd3p2,dest_exponent,guardbit,
stickybit,inexact);
/* return rounded number */
if (inexact) {
switch (Rounding_mode()) {
case ROUNDPLUS:
if (Dbl_iszero_sign(resultp1)) {
Dbl_increment(opnd3p1,opnd3p2);
}
break;
case ROUNDMINUS:
if (Dbl_isone_sign(resultp1)) {
Dbl_increment(opnd3p1,opnd3p2);
}
break;
case ROUNDNEAREST:
if (guardbit && (stickybit ||
Dbl_isone_lowmantissap2(opnd3p2))) {
Dbl_increment(opnd3p1,opnd3p2);
}
break;
}
if (is_tiny) Set_underflowflag();
}
Dbl_set_exponentmantissa(resultp1,resultp2,opnd3p1,opnd3p2);
}
else Dbl_set_exponent(resultp1,dest_exponent);
Dbl_copytoptr(resultp1,resultp2,dstptr);
/* check for inexact */
if (inexact) {
if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
else Set_inexactflag();
}
return(NOEXCEPTION);
}
/*
* dbl_cmp: compare two values
*/
int
dbl_fcmp (dbl_floating_point * leftptr, dbl_floating_point * rightptr,
unsigned int cond, unsigned int *status)
/* The predicate to be tested */
{
register unsigned int leftp1, leftp2, rightp1, rightp2;
register int xorresult;
/* Create local copies of the numbers */
Dbl_copyfromptr(leftptr,leftp1,leftp2);
Dbl_copyfromptr(rightptr,rightp1,rightp2);
/*
* Test for NaN
*/
if( (Dbl_exponent(leftp1) == DBL_INFINITY_EXPONENT)
|| (Dbl_exponent(rightp1) == DBL_INFINITY_EXPONENT) )
{
/* Check if a NaN is involved. Signal an invalid exception when
* comparing a signaling NaN or when comparing quiet NaNs and the
* low bit of the condition is set */
if( ((Dbl_exponent(leftp1) == DBL_INFINITY_EXPONENT)
&& Dbl_isnotzero_mantissa(leftp1,leftp2)
&& (Exception(cond) || Dbl_isone_signaling(leftp1)))
||
((Dbl_exponent(rightp1) == DBL_INFINITY_EXPONENT)
&& Dbl_isnotzero_mantissa(rightp1,rightp2)
&& (Exception(cond) || Dbl_isone_signaling(rightp1))) )
{
if( Is_invalidtrap_enabled() ) {
Set_status_cbit(Unordered(cond));
return(INVALIDEXCEPTION);
}
else Set_invalidflag();
Set_status_cbit(Unordered(cond));
return(NOEXCEPTION);
}
/* All the exceptional conditions are handled, now special case
NaN compares */
else if( ((Dbl_exponent(leftp1) == DBL_INFINITY_EXPONENT)
&& Dbl_isnotzero_mantissa(leftp1,leftp2))
||
((Dbl_exponent(rightp1) == DBL_INFINITY_EXPONENT)
&& Dbl_isnotzero_mantissa(rightp1,rightp2)) )
{
/* NaNs always compare unordered. */
Set_status_cbit(Unordered(cond));
return(NOEXCEPTION);
}
/* infinities will drop down to the normal compare mechanisms */
}
/* First compare for unequal signs => less or greater or
* special equal case */
Dbl_xortointp1(leftp1,rightp1,xorresult);
if( xorresult < 0 )
{
/* left negative => less, left positive => greater.
* equal is possible if both operands are zeros. */
if( Dbl_iszero_exponentmantissa(leftp1,leftp2)
&& Dbl_iszero_exponentmantissa(rightp1,rightp2) )
{
Set_status_cbit(Equal(cond));
}
else if( Dbl_isone_sign(leftp1) )
{
Set_status_cbit(Lessthan(cond));
}
else
{
Set_status_cbit(Greaterthan(cond));
}
}
/* Signs are the same. Treat negative numbers separately
* from the positives because of the reversed sense. */
else if(Dbl_isequal(leftp1,leftp2,rightp1,rightp2))
{
Set_status_cbit(Equal(cond));
}
else if( Dbl_iszero_sign(leftp1) )
{
/* Positive compare */
if( Dbl_allp1(leftp1) < Dbl_allp1(rightp1) )
{
Set_status_cbit(Lessthan(cond));
}
else if( Dbl_allp1(leftp1) > Dbl_allp1(rightp1) )
{
Set_status_cbit(Greaterthan(cond));
}
else
{
/* Equal first parts. Now we must use unsigned compares to
* resolve the two possibilities. */
if( Dbl_allp2(leftp2) < Dbl_allp2(rightp2) )
{
Set_status_cbit(Lessthan(cond));
}
else
{
Set_status_cbit(Greaterthan(cond));
}
}
}
else
{
/* Negative compare. Signed or unsigned compares
* both work the same. That distinction is only
* important when the sign bits differ. */
if( Dbl_allp1(leftp1) > Dbl_allp1(rightp1) )
{
Set_status_cbit(Lessthan(cond));
}
else if( Dbl_allp1(leftp1) < Dbl_allp1(rightp1) )
{
Set_status_cbit(Greaterthan(cond));
}
else
{
/* Equal first parts. Now we must use unsigned compares to
* resolve the two possibilities. */
if( Dbl_allp2(leftp2) > Dbl_allp2(rightp2) )
{
Set_status_cbit(Lessthan(cond));
}
else
{
Set_status_cbit(Greaterthan(cond));
}
}
}
return(NOEXCEPTION);
}
int
dbl_fdiv (dbl_floating_point * srcptr1, dbl_floating_point * srcptr2,
dbl_floating_point * dstptr, unsigned int *status)
{
register unsigned int opnd1p1, opnd1p2, opnd2p1, opnd2p2;
register unsigned int opnd3p1, opnd3p2, resultp1, resultp2;
register int dest_exponent, count;
register boolean inexact = FALSE, guardbit = FALSE, stickybit = FALSE;
boolean is_tiny;
Dbl_copyfromptr(srcptr1,opnd1p1,opnd1p2);
Dbl_copyfromptr(srcptr2,opnd2p1,opnd2p2);
/*
*/
if (Dbl_sign(opnd1p1) ^ Dbl_sign(opnd2p1))
Dbl_setnegativezerop1(resultp1);
else Dbl_setzerop1(resultp1);
/*
*/
if (Dbl_isinfinity_exponent(opnd1p1)) {
if (Dbl_iszero_mantissa(opnd1p1,opnd1p2)) {
if (Dbl_isnotnan(opnd2p1,opnd2p2)) {
if (Dbl_isinfinity(opnd2p1,opnd2p2)) {
/*
*/
if (Is_invalidtrap_enabled())
return(INVALIDEXCEPTION);
Set_invalidflag();
Dbl_makequietnan(resultp1,resultp2);
Dbl_copytoptr(resultp1,resultp2,dstptr);
return(NOEXCEPTION);
}
/*
*/
Dbl_setinfinity_exponentmantissa(resultp1,resultp2);
Dbl_copytoptr(resultp1,resultp2,dstptr);
return(NOEXCEPTION);
}
}
else {
/*
*/
if (Dbl_isone_signaling(opnd1p1)) {
/* */
if (Is_invalidtrap_enabled())
return(INVALIDEXCEPTION);
/* */
Set_invalidflag();
Dbl_set_quiet(opnd1p1);
}
/*
*/
else if (Dbl_is_signalingnan(opnd2p1)) {
/* */
if (Is_invalidtrap_enabled())
return(INVALIDEXCEPTION);
/* */
Set_invalidflag();
Dbl_set_quiet(opnd2p1);
Dbl_copytoptr(opnd2p1,opnd2p2,dstptr);
return(NOEXCEPTION);
}
/*
*/
Dbl_copytoptr(opnd1p1,opnd1p2,dstptr);
return(NOEXCEPTION);
}
}
/*
*/
if (Dbl_isinfinity_exponent(opnd2p1)) {
if (Dbl_iszero_mantissa(opnd2p1,opnd2p2)) {
/*
*/
Dbl_setzero_exponentmantissa(resultp1,resultp2);
Dbl_copytoptr(resultp1,resultp2,dstptr);
return(NOEXCEPTION);
}
/*
*/
if (Dbl_isone_signaling(opnd2p1)) {
/* */
if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
/* */
Set_invalidflag();
Dbl_set_quiet(opnd2p1);
}
/*
*/
Dbl_copytoptr(opnd2p1,opnd2p2,dstptr);
return(NOEXCEPTION);
}
/*
*/
if (Dbl_iszero_exponentmantissa(opnd2p1,opnd2p2)) {
if (Dbl_iszero_exponentmantissa(opnd1p1,opnd1p2)) {
/* */
if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
Set_invalidflag();
Dbl_makequietnan(resultp1,resultp2);
Dbl_copytoptr(resultp1,resultp2,dstptr);
return(NOEXCEPTION);
}
if (Is_divisionbyzerotrap_enabled())
return(DIVISIONBYZEROEXCEPTION);
Set_divisionbyzeroflag();
Dbl_setinfinity_exponentmantissa(resultp1,resultp2);
Dbl_copytoptr(resultp1,resultp2,dstptr);
return(NOEXCEPTION);
}
/*
*/
dest_exponent = Dbl_exponent(opnd1p1) - Dbl_exponent(opnd2p1) + DBL_BIAS;
/*
*/
if (Dbl_isnotzero_exponent(opnd1p1)) {
/* */
Dbl_clear_signexponent_set_hidden(opnd1p1);
}
else {
/* */
if (Dbl_iszero_mantissa(opnd1p1,opnd1p2)) {
Dbl_setzero_exponentmantissa(resultp1,resultp2);
Dbl_copytoptr(resultp1,resultp2,dstptr);
return(NOEXCEPTION);
}
/* */
Dbl_clear_signexponent(opnd1p1);
Dbl_leftshiftby1(opnd1p1,opnd1p2);
Dbl_normalize(opnd1p1,opnd1p2,dest_exponent);
}
/* */
if (Dbl_isnotzero_exponent(opnd2p1)) {
Dbl_clear_signexponent_set_hidden(opnd2p1);
}
else {
/* */
Dbl_clear_signexponent(opnd2p1);
Dbl_leftshiftby1(opnd2p1,opnd2p2);
while (Dbl_iszero_hiddenhigh7mantissa(opnd2p1)) {
dest_exponent+=8;
Dbl_leftshiftby8(opnd2p1,opnd2p2);
}
if (Dbl_iszero_hiddenhigh3mantissa(opnd2p1)) {
dest_exponent+=4;
Dbl_leftshiftby4(opnd2p1,opnd2p2);
}
while (Dbl_iszero_hidden(opnd2p1)) {
dest_exponent++;
Dbl_leftshiftby1(opnd2p1,opnd2p2);
}
}
/* */
/*
*/
Twoword_subtract(opnd1p1,opnd1p2,opnd2p1,opnd2p2);
Dbl_setzero(opnd3p1,opnd3p2);
for (count=1; count <= DBL_P && (opnd1p1 || opnd1p2); count++) {
Dbl_leftshiftby1(opnd1p1,opnd1p2);
Dbl_leftshiftby1(opnd3p1,opnd3p2);
if (Dbl_iszero_sign(opnd1p1)) {
Dbl_setone_lowmantissap2(opnd3p2);
Twoword_subtract(opnd1p1,opnd1p2,opnd2p1,opnd2p2);
}
else {
Twoword_add(opnd1p1, opnd1p2, opnd2p1, opnd2p2);
}
}
if (count <= DBL_P) {
Dbl_leftshiftby1(opnd3p1,opnd3p2);
Dbl_setone_lowmantissap2(opnd3p2);
Dbl_leftshift(opnd3p1,opnd3p2,(DBL_P-count));
if (Dbl_iszero_hidden(opnd3p1)) {
Dbl_leftshiftby1(opnd3p1,opnd3p2);
dest_exponent--;
}
}
else {
if (Dbl_iszero_hidden(opnd3p1)) {
/* */
Dbl_leftshiftby1(opnd1p1,opnd1p2);
Dbl_leftshiftby1(opnd3p1,opnd3p2);
if (Dbl_iszero_sign(opnd1p1)) {
Dbl_setone_lowmantissap2(opnd3p2);
Twoword_subtract(opnd1p1,opnd1p2,opnd2p1,opnd2p2);
}
else {
Twoword_add(opnd1p1,opnd1p2,opnd2p1,opnd2p2);
}
dest_exponent--;
}
if (Dbl_iszero_sign(opnd1p1)) guardbit = TRUE;
stickybit = Dbl_allp1(opnd1p1) || Dbl_allp2(opnd1p2);
}
inexact = guardbit | stickybit;
/*
*/
if (inexact && (dest_exponent > 0 || Is_underflowtrap_enabled())) {
Dbl_clear_signexponent(opnd3p1);
switch (Rounding_mode()) {
case ROUNDPLUS:
if (Dbl_iszero_sign(resultp1))
Dbl_increment(opnd3p1,opnd3p2);
break;
case ROUNDMINUS:
if (Dbl_isone_sign(resultp1))
Dbl_increment(opnd3p1,opnd3p2);
break;
case ROUNDNEAREST:
if (guardbit && (stickybit ||
Dbl_isone_lowmantissap2(opnd3p2))) {
Dbl_increment(opnd3p1,opnd3p2);
}
}
if (Dbl_isone_hidden(opnd3p1)) dest_exponent++;
}
Dbl_set_mantissa(resultp1,resultp2,opnd3p1,opnd3p2);
/*
*/
if (dest_exponent >= DBL_INFINITY_EXPONENT) {
/* */
if (Is_overflowtrap_enabled()) {
/*
*/
Dbl_setwrapped_exponent(resultp1,dest_exponent,ovfl);
Dbl_copytoptr(resultp1,resultp2,dstptr);
if (inexact)
if (Is_inexacttrap_enabled())
return(OVERFLOWEXCEPTION | INEXACTEXCEPTION);
else Set_inexactflag();
return(OVERFLOWEXCEPTION);
}
Set_overflowflag();
/* */
Dbl_setoverflow(resultp1,resultp2);
inexact = TRUE;
}
/*
*/
else if (dest_exponent <= 0) {
/* */
if (Is_underflowtrap_enabled()) {
/*
*/
Dbl_setwrapped_exponent(resultp1,dest_exponent,unfl);
Dbl_copytoptr(resultp1,resultp2,dstptr);
if (inexact)
if (Is_inexacttrap_enabled())
return(UNDERFLOWEXCEPTION | INEXACTEXCEPTION);
else Set_inexactflag();
return(UNDERFLOWEXCEPTION);
}
/* */
is_tiny = TRUE;
if (dest_exponent == 0 && inexact) {
switch (Rounding_mode()) {
case ROUNDPLUS:
if (Dbl_iszero_sign(resultp1)) {
Dbl_increment(opnd3p1,opnd3p2);
if (Dbl_isone_hiddenoverflow(opnd3p1))
is_tiny = FALSE;
Dbl_decrement(opnd3p1,opnd3p2);
}
break;
case ROUNDMINUS:
if (Dbl_isone_sign(resultp1)) {
Dbl_increment(opnd3p1,opnd3p2);
if (Dbl_isone_hiddenoverflow(opnd3p1))
is_tiny = FALSE;
Dbl_decrement(opnd3p1,opnd3p2);
}
break;
case ROUNDNEAREST:
if (guardbit && (stickybit ||
Dbl_isone_lowmantissap2(opnd3p2))) {
Dbl_increment(opnd3p1,opnd3p2);
if (Dbl_isone_hiddenoverflow(opnd3p1))
is_tiny = FALSE;
Dbl_decrement(opnd3p1,opnd3p2);
}
break;
}
}
/*
*/
stickybit = inexact;
Dbl_denormalize(opnd3p1,opnd3p2,dest_exponent,guardbit,
stickybit,inexact);
/* */
if (inexact) {
switch (Rounding_mode()) {
case ROUNDPLUS:
if (Dbl_iszero_sign(resultp1)) {
Dbl_increment(opnd3p1,opnd3p2);
}
break;
case ROUNDMINUS:
if (Dbl_isone_sign(resultp1)) {
Dbl_increment(opnd3p1,opnd3p2);
}
break;
case ROUNDNEAREST:
if (guardbit && (stickybit ||
Dbl_isone_lowmantissap2(opnd3p2))) {
Dbl_increment(opnd3p1,opnd3p2);
}
break;
}
if (is_tiny) Set_underflowflag();
}
Dbl_set_exponentmantissa(resultp1,resultp2,opnd3p1,opnd3p2);
}
else Dbl_set_exponent(resultp1,dest_exponent);
Dbl_copytoptr(resultp1,resultp2,dstptr);
/* */
if (inexact) {
if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
else Set_inexactflag();
}
return(NOEXCEPTION);
}
int
dbl_fcmp (dbl_floating_point * leftptr, dbl_floating_point * rightptr,
unsigned int cond, unsigned int *status)
/* */
{
register unsigned int leftp1, leftp2, rightp1, rightp2;
register int xorresult;
/* */
Dbl_copyfromptr(leftptr,leftp1,leftp2);
Dbl_copyfromptr(rightptr,rightp1,rightp2);
/*
*/
if( (Dbl_exponent(leftp1) == DBL_INFINITY_EXPONENT)
|| (Dbl_exponent(rightp1) == DBL_INFINITY_EXPONENT) )
{
/*
*/
if( ((Dbl_exponent(leftp1) == DBL_INFINITY_EXPONENT)
&& Dbl_isnotzero_mantissa(leftp1,leftp2)
&& (Exception(cond) || Dbl_isone_signaling(leftp1)))
||
((Dbl_exponent(rightp1) == DBL_INFINITY_EXPONENT)
&& Dbl_isnotzero_mantissa(rightp1,rightp2)
&& (Exception(cond) || Dbl_isone_signaling(rightp1))) )
{
if( Is_invalidtrap_enabled() ) {
Set_status_cbit(Unordered(cond));
return(INVALIDEXCEPTION);
}
else Set_invalidflag();
Set_status_cbit(Unordered(cond));
return(NOEXCEPTION);
}
/*
*/
else if( ((Dbl_exponent(leftp1) == DBL_INFINITY_EXPONENT)
&& Dbl_isnotzero_mantissa(leftp1,leftp2))
||
((Dbl_exponent(rightp1) == DBL_INFINITY_EXPONENT)
&& Dbl_isnotzero_mantissa(rightp1,rightp2)) )
{
/* */
Set_status_cbit(Unordered(cond));
return(NOEXCEPTION);
}
/* */
}
/*
*/
Dbl_xortointp1(leftp1,rightp1,xorresult);
if( xorresult < 0 )
{
/*
*/
if( Dbl_iszero_exponentmantissa(leftp1,leftp2)
&& Dbl_iszero_exponentmantissa(rightp1,rightp2) )
{
Set_status_cbit(Equal(cond));
}
else if( Dbl_isone_sign(leftp1) )
{
Set_status_cbit(Lessthan(cond));
}
else
{
Set_status_cbit(Greaterthan(cond));
}
}
/*
*/
else if(Dbl_isequal(leftp1,leftp2,rightp1,rightp2))
{
Set_status_cbit(Equal(cond));
}
else if( Dbl_iszero_sign(leftp1) )
{
/* */
if( Dbl_allp1(leftp1) < Dbl_allp1(rightp1) )
{
Set_status_cbit(Lessthan(cond));
}
else if( Dbl_allp1(leftp1) > Dbl_allp1(rightp1) )
{
Set_status_cbit(Greaterthan(cond));
}
else
{
/*
*/
if( Dbl_allp2(leftp2) < Dbl_allp2(rightp2) )
{
Set_status_cbit(Lessthan(cond));
}
else
{
Set_status_cbit(Greaterthan(cond));
}
}
}
else
{
/*
*/
if( Dbl_allp1(leftp1) > Dbl_allp1(rightp1) )
{
Set_status_cbit(Lessthan(cond));
}
else if( Dbl_allp1(leftp1) < Dbl_allp1(rightp1) )
{
Set_status_cbit(Greaterthan(cond));
}
else
{
/*
*/
if( Dbl_allp2(leftp2) > Dbl_allp2(rightp2) )
{
Set_status_cbit(Lessthan(cond));
}
else
{
Set_status_cbit(Greaterthan(cond));
}
}
}
return(NOEXCEPTION);
}
