void
dbl_denormalize(unsigned int *dbl_opndp1,
unsigned int * dbl_opndp2,
boolean *inexactflag,
int rmode)
{
unsigned int opndp1, opndp2;
int sign, exponent;
boolean guardbit = FALSE, stickybit, inexact;
opndp1 = *dbl_opndp1;
opndp2 = *dbl_opndp2;
stickybit = *inexactflag;
exponent = Dbl_exponent(opndp1) - DBL_WRAP;
sign = Dbl_sign(opndp1);
Dbl_denormalize(opndp1,opndp2,exponent,guardbit,stickybit,inexact);
if (inexact) {
switch (rmode) {
case ROUNDPLUS:
if (sign == 0) {
Dbl_increment(opndp1,opndp2);
}
break;
case ROUNDMINUS:
if (sign != 0) {
Dbl_increment(opndp1,opndp2);
}
break;
case ROUNDNEAREST:
if (guardbit && (stickybit ||
Dbl_isone_lowmantissap2(opndp2))) {
Dbl_increment(opndp1,opndp2);
}
break;
}
}
Dbl_set_sign(opndp1,sign);
*dbl_opndp1 = opndp1;
*dbl_opndp2 = opndp2;
*inexactflag = inexact;
return;
}
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);
}
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_fmpy(
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_iszero_exponentmantissa(opnd2p1,opnd2p2)) {
/*
* invalid since operands are infinity
* and zero
*/
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)) {
if (Dbl_iszero_exponentmantissa(opnd1p1,opnd1p2)) {
/* invalid since operands are zero & infinity */
if (Is_invalidtrap_enabled())
return(INVALIDEXCEPTION);
Set_invalidflag();
Dbl_makequietnan(opnd2p1,opnd2p2);
Dbl_copytoptr(opnd2p1,opnd2p2,dstptr);
return(NOEXCEPTION);
}
/*
* return infinity
*/
Dbl_setinfinity_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);
}
/*
* 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, adjust exponent */
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 {
/* check for zero */
if (Dbl_iszero_mantissa(opnd2p1,opnd2p2)) {
Dbl_setzero_exponentmantissa(resultp1,resultp2);
Dbl_copytoptr(resultp1,resultp2,dstptr);
return(NOEXCEPTION);
}
/* is denormalized; want to normalize */
Dbl_clear_signexponent(opnd2p1);
Dbl_leftshiftby1(opnd2p1,opnd2p2);
Dbl_normalize(opnd2p1,opnd2p2,dest_exponent);
}
/* Multiply two source mantissas together */
/* make room for guard bits */
Dbl_leftshiftby7(opnd2p1,opnd2p2);
Dbl_setzero(opnd3p1,opnd3p2);
/*
* Four bits at a time are inspected in each loop, and a
* simple shift and add multiply algorithm is used.
*/
for (count=1;count<=DBL_P;count+=4) {
stickybit |= Dlow4p2(opnd3p2);
Dbl_rightshiftby4(opnd3p1,opnd3p2);
if (Dbit28p2(opnd1p2)) {
/* Twoword_add should be an ADDC followed by an ADD. */
Twoword_add(opnd3p1, opnd3p2, opnd2p1<<3 | opnd2p2>>29,
opnd2p2<<3);
}
if (Dbit29p2(opnd1p2)) {
Twoword_add(opnd3p1, opnd3p2, opnd2p1<<2 | opnd2p2>>30,
opnd2p2<<2);
}
if (Dbit30p2(opnd1p2)) {
Twoword_add(opnd3p1, opnd3p2, opnd2p1<<1 | opnd2p2>>31,
opnd2p2<<1);
}
if (Dbit31p2(opnd1p2)) {
Twoword_add(opnd3p1, opnd3p2, opnd2p1, opnd2p2);
}
Dbl_rightshiftby4(opnd1p1,opnd1p2);
}
if (Dbit3p1(opnd3p1)==0) {
Dbl_leftshiftby1(opnd3p1,opnd3p2);
}
else {
/* result mantissa >= 2. */
dest_exponent++;
}
/* check for denormalized result */
while (Dbit3p1(opnd3p1)==0) {
Dbl_leftshiftby1(opnd3p1,opnd3p2);
dest_exponent--;
}
/*
* check for guard, sticky and inexact bits
*/
stickybit |= Dallp2(opnd3p2) << 25;
guardbit = (Dallp2(opnd3p2) << 24) >> 31;
inexact = guardbit | stickybit;
/* align result mantissa */
Dbl_rightshiftby8(opnd3p1,opnd3p2);
/*
* 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) {
if (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);
}
inexact = TRUE;
Set_overflowflag();
/* set result to infinity or largest number */
Dbl_setoverflow(resultp1,resultp2);
}
/*
* 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 zero or smallest 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);
/* check for inexact */
Dbl_copytoptr(resultp1,resultp2,dstptr);
if (inexact) {
if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
else Set_inexactflag();
}
return(NOEXCEPTION);
}
int
dbl_fmpyfadd(
dbl_floating_point *src1ptr,
dbl_floating_point *src2ptr,
dbl_floating_point *src3ptr,
unsigned int *status,
dbl_floating_point *dstptr)
{
unsigned int opnd1p1, opnd1p2, opnd2p1, opnd2p2, opnd3p1, opnd3p2;
register unsigned int tmpresp1, tmpresp2, tmpresp3, tmpresp4;
unsigned int rightp1, rightp2, rightp3, rightp4;
unsigned int resultp1, resultp2 = 0, resultp3 = 0, resultp4 = 0;
register int mpy_exponent, add_exponent, count;
boolean inexact = FALSE, is_tiny = FALSE;
unsigned int signlessleft1, signlessright1, save;
register int result_exponent, diff_exponent;
int sign_save, jumpsize;
Dbl_copyfromptr(src1ptr,opnd1p1,opnd1p2);
Dbl_copyfromptr(src2ptr,opnd2p1,opnd2p2);
Dbl_copyfromptr(src3ptr,opnd3p1,opnd3p2);
if (Dbl_sign(opnd1p1) ^ Dbl_sign(opnd2p1))
Dbl_setnegativezerop1(resultp1);
else Dbl_setzerop1(resultp1);
mpy_exponent = Dbl_exponent(opnd1p1) + Dbl_exponent(opnd2p1) - DBL_BIAS;
if (Dbl_isinfinity_exponent(opnd1p1)) {
if (Dbl_iszero_mantissa(opnd1p1,opnd1p2)) {
if (Dbl_isnotnan(opnd2p1,opnd2p2) &&
Dbl_isnotnan(opnd3p1,opnd3p2)) {
if (Dbl_iszero_exponentmantissa(opnd2p1,opnd2p2)) {
if (Is_invalidtrap_enabled())
return(OPC_2E_INVALIDEXCEPTION);
Set_invalidflag();
Dbl_makequietnan(resultp1,resultp2);
Dbl_copytoptr(resultp1,resultp2,dstptr);
return(NOEXCEPTION);
}
if (Dbl_isinfinity(opnd3p1,opnd3p2) &&
(Dbl_sign(resultp1) ^ Dbl_sign(opnd3p1))) {
if (Is_invalidtrap_enabled())
return(OPC_2E_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(OPC_2E_INVALIDEXCEPTION);
Set_invalidflag();
Dbl_set_quiet(opnd1p1);
}
else if (Dbl_is_signalingnan(opnd2p1)) {
if (Is_invalidtrap_enabled())
return(OPC_2E_INVALIDEXCEPTION);
Set_invalidflag();
Dbl_set_quiet(opnd2p1);
Dbl_copytoptr(opnd2p1,opnd2p2,dstptr);
return(NOEXCEPTION);
}
else if (Dbl_is_signalingnan(opnd3p1)) {
if (Is_invalidtrap_enabled())
return(OPC_2E_INVALIDEXCEPTION);
Set_invalidflag();
Dbl_set_quiet(opnd3p1);
Dbl_copytoptr(opnd3p1,opnd3p2,dstptr);
return(NOEXCEPTION);
}
Dbl_copytoptr(opnd1p1,opnd1p2,dstptr);
return(NOEXCEPTION);
}
}
if (Dbl_isinfinity_exponent(opnd2p1)) {
if (Dbl_iszero_mantissa(opnd2p1,opnd2p2)) {
if (Dbl_isnotnan(opnd3p1,opnd3p2)) {
if (Dbl_iszero_exponentmantissa(opnd1p1,opnd1p2)) {
if (Is_invalidtrap_enabled())
return(OPC_2E_INVALIDEXCEPTION);
Set_invalidflag();
Dbl_makequietnan(opnd2p1,opnd2p2);
Dbl_copytoptr(opnd2p1,opnd2p2,dstptr);
return(NOEXCEPTION);
}
if (Dbl_isinfinity(opnd3p1,opnd3p2) &&
(Dbl_sign(resultp1) ^ Dbl_sign(opnd3p1))) {
if (Is_invalidtrap_enabled())
return(OPC_2E_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(opnd2p1)) {
if (Is_invalidtrap_enabled())
return(OPC_2E_INVALIDEXCEPTION);
Set_invalidflag();
Dbl_set_quiet(opnd2p1);
}
else if (Dbl_is_signalingnan(opnd3p1)) {
if (Is_invalidtrap_enabled())
return(OPC_2E_INVALIDEXCEPTION);
Set_invalidflag();
Dbl_set_quiet(opnd3p1);
Dbl_copytoptr(opnd3p1,opnd3p2,dstptr);
return(NOEXCEPTION);
}
Dbl_copytoptr(opnd2p1,opnd2p2,dstptr);
return(NOEXCEPTION);
}
}
if (Dbl_isinfinity_exponent(opnd3p1)) {
if (Dbl_iszero_mantissa(opnd3p1,opnd3p2)) {
Dbl_copytoptr(opnd3p1,opnd3p2,dstptr);
return(NOEXCEPTION);
} else {
if (Dbl_isone_signaling(opnd3p1)) {
if (Is_invalidtrap_enabled())
return(OPC_2E_INVALIDEXCEPTION);
Set_invalidflag();
Dbl_set_quiet(opnd3p1);
}
Dbl_copytoptr(opnd3p1,opnd3p2,dstptr);
return(NOEXCEPTION);
}
}
if (Dbl_isnotzero_exponent(opnd1p1)) {
Dbl_clear_signexponent_set_hidden(opnd1p1);
}
else {
if (Dbl_iszero_mantissa(opnd1p1,opnd1p2)) {
if (Dbl_iszero_exponentmantissa(opnd3p1,opnd3p2)) {
if (Is_rounding_mode(ROUNDMINUS)) {
Dbl_or_signs(opnd3p1,resultp1);
} else {
Dbl_and_signs(opnd3p1,resultp1);
}
}
else if (Dbl_iszero_exponent(opnd3p1) &&
Is_underflowtrap_enabled()) {
sign_save = Dbl_signextendedsign(opnd3p1);
result_exponent = 0;
Dbl_leftshiftby1(opnd3p1,opnd3p2);
Dbl_normalize(opnd3p1,opnd3p2,result_exponent);
Dbl_set_sign(opnd3p1,sign_save);
Dbl_setwrapped_exponent(opnd3p1,result_exponent,
unfl);
Dbl_copytoptr(opnd3p1,opnd3p2,dstptr);
return(OPC_2E_UNDERFLOWEXCEPTION);
}
Dbl_copytoptr(opnd3p1,opnd3p2,dstptr);
return(NOEXCEPTION);
}
Dbl_clear_signexponent(opnd1p1);
Dbl_leftshiftby1(opnd1p1,opnd1p2);
Dbl_normalize(opnd1p1,opnd1p2,mpy_exponent);
}
if (Dbl_isnotzero_exponent(opnd2p1)) {
Dbl_clear_signexponent_set_hidden(opnd2p1);
}
else {
if (Dbl_iszero_mantissa(opnd2p1,opnd2p2)) {
if (Dbl_iszero_exponentmantissa(opnd3p1,opnd3p2)) {
if (Is_rounding_mode(ROUNDMINUS)) {
Dbl_or_signs(opnd3p1,resultp1);
} else {
Dbl_and_signs(opnd3p1,resultp1);
}
}
else if (Dbl_iszero_exponent(opnd3p1) &&
Is_underflowtrap_enabled()) {
sign_save = Dbl_signextendedsign(opnd3p1);
result_exponent = 0;
Dbl_leftshiftby1(opnd3p1,opnd3p2);
Dbl_normalize(opnd3p1,opnd3p2,result_exponent);
Dbl_set_sign(opnd3p1,sign_save);
Dbl_setwrapped_exponent(opnd3p1,result_exponent,
unfl);
Dbl_copytoptr(opnd3p1,opnd3p2,dstptr);
return(OPC_2E_UNDERFLOWEXCEPTION);
}
Dbl_copytoptr(opnd3p1,opnd3p2,dstptr);
return(NOEXCEPTION);
}
Dbl_clear_signexponent(opnd2p1);
Dbl_leftshiftby1(opnd2p1,opnd2p2);
Dbl_normalize(opnd2p1,opnd2p2,mpy_exponent);
}
Dblext_setzero(tmpresp1,tmpresp2,tmpresp3,tmpresp4);
for (count = DBL_P-1; count >= 0; count -= 4) {
Dblext_rightshiftby4(tmpresp1,tmpresp2,tmpresp3,tmpresp4);
if (Dbit28p2(opnd1p2)) {
Fourword_add(tmpresp1, tmpresp2, tmpresp3, tmpresp4,
opnd2p1<<3 | opnd2p2>>29, opnd2p2<<3, 0, 0);
}
if (Dbit29p2(opnd1p2)) {
Fourword_add(tmpresp1, tmpresp2, tmpresp3, tmpresp4,
opnd2p1<<2 | opnd2p2>>30, opnd2p2<<2, 0, 0);
}
if (Dbit30p2(opnd1p2)) {
Fourword_add(tmpresp1, tmpresp2, tmpresp3, tmpresp4,
opnd2p1<<1 | opnd2p2>>31, opnd2p2<<1, 0, 0);
}
if (Dbit31p2(opnd1p2)) {
Fourword_add(tmpresp1, tmpresp2, tmpresp3, tmpresp4,
opnd2p1, opnd2p2, 0, 0);
}
Dbl_rightshiftby4(opnd1p1,opnd1p2);
}
if (Is_dexthiddenoverflow(tmpresp1)) {
mpy_exponent++;
Dblext_rightshiftby1(tmpresp1,tmpresp2,tmpresp3,tmpresp4);
}
Dblext_set_sign(tmpresp1,Dbl_sign(resultp1));
add_exponent = Dbl_exponent(opnd3p1);
if (add_exponent == 0) {
if (Dbl_iszero_mantissa(opnd3p1,opnd3p2)) {
result_exponent = mpy_exponent;
Dblext_copy(tmpresp1,tmpresp2,tmpresp3,tmpresp4,
resultp1,resultp2,resultp3,resultp4);
sign_save = Dbl_signextendedsign(resultp1);
goto round;
}
sign_save = Dbl_signextendedsign(opnd3p1);
Dbl_clear_signexponent(opnd3p1);
Dbl_leftshiftby1(opnd3p1,opnd3p2);
Dbl_normalize(opnd3p1,opnd3p2,add_exponent);
Dbl_set_sign(opnd3p1,sign_save);
} else {
Dbl_clear_exponent_set_hidden(opnd3p1);
}
Dbl_copyto_dblext(opnd3p1,opnd3p2,rightp1,rightp2,rightp3,rightp4);
Dblext_xortointp1(tmpresp1,rightp1,save);
Dblext_copytoint_exponentmantissap1(tmpresp1,signlessleft1);
Dblext_copytoint_exponentmantissap1(rightp1,signlessright1);
if (mpy_exponent < add_exponent || mpy_exponent == add_exponent &&
Dblext_ismagnitudeless(tmpresp2,rightp2,signlessleft1,signlessright1)){
Dblext_xorfromintp1(save,rightp1,rightp1);
Dblext_xorfromintp1(save,tmpresp1,tmpresp1);
Dblext_swap_lower(tmpresp2,tmpresp3,tmpresp4,
rightp2,rightp3,rightp4);
diff_exponent = add_exponent - mpy_exponent;
result_exponent = add_exponent;
} else {
diff_exponent = mpy_exponent - add_exponent;
result_exponent = mpy_exponent;
}
if (diff_exponent > DBLEXT_THRESHOLD) {
diff_exponent = DBLEXT_THRESHOLD;
}
Dblext_clear_sign(rightp1);
Dblext_right_align(rightp1,rightp2,rightp3,rightp4,
diff_exponent);
if ((int)save < 0) {
Dblext_subtract(tmpresp1,tmpresp2,tmpresp3,tmpresp4,
rightp1,rightp2,rightp3,rightp4,
resultp1,resultp2,resultp3,resultp4);
sign_save = Dbl_signextendedsign(resultp1);
if (Dbl_iszero_hidden(resultp1)) {
Dblext_leftshiftby1(resultp1,resultp2,resultp3,
resultp4);
if(Dblext_iszero(resultp1,resultp2,resultp3,resultp4)){
if (Is_rounding_mode(ROUNDMINUS))
Dbl_setone_sign(resultp1);
Dbl_copytoptr(resultp1,resultp2,dstptr);
return(NOEXCEPTION);
}
result_exponent--;
if (Dbl_isone_hidden(resultp1)) {
goto round;
}
while (Dbl_iszero_hiddenhigh7mantissa(resultp1)) {
Dblext_leftshiftby8(resultp1,resultp2,resultp3,resultp4);
result_exponent -= 8;
}
if (Dbl_iszero_hiddenhigh3mantissa(resultp1)) {
Dblext_leftshiftby4(resultp1,resultp2,resultp3,resultp4);
result_exponent -= 4;
}
jumpsize = Dbl_hiddenhigh3mantissa(resultp1);
if (jumpsize <= 7) switch(jumpsize) {
case 1:
Dblext_leftshiftby3(resultp1,resultp2,resultp3,
resultp4);
result_exponent -= 3;
break;
case 2:
case 3:
Dblext_leftshiftby2(resultp1,resultp2,resultp3,
resultp4);
result_exponent -= 2;
break;
case 4:
case 5:
case 6:
case 7:
Dblext_leftshiftby1(resultp1,resultp2,resultp3,
resultp4);
result_exponent -= 1;
break;
}
}
}
else {
Dblext_addition(tmpresp1,tmpresp2,tmpresp3,tmpresp4,
rightp1,rightp2,rightp3,rightp4,
resultp1,resultp2,resultp3,resultp4);
sign_save = Dbl_signextendedsign(resultp1);
if (Dbl_isone_hiddenoverflow(resultp1)) {
Dblext_arithrightshiftby1(resultp1,resultp2,resultp3,
resultp4);
result_exponent++;
}
}
round:
if (result_exponent <= 0 && !Is_underflowtrap_enabled()) {
Dblext_denormalize(resultp1,resultp2,resultp3,resultp4,
result_exponent,is_tiny);
}
Dbl_set_sign(resultp1,sign_save);
if (Dblext_isnotzero_mantissap3(resultp3) ||
Dblext_isnotzero_mantissap4(resultp4)) {
inexact = TRUE;
switch(Rounding_mode()) {
case ROUNDNEAREST:
if (Dblext_isone_highp3(resultp3)) {
if (Dblext_isnotzero_low31p3(resultp3) ||
Dblext_isnotzero_mantissap4(resultp4) ||
Dblext_isone_lowp2(resultp2)) {
Dbl_increment(resultp1,resultp2);
}
}
break;
case ROUNDPLUS:
if (Dbl_iszero_sign(resultp1)) {
Dbl_increment(resultp1,resultp2);
}
break;
case ROUNDMINUS:
if (Dbl_isone_sign(resultp1)) {
Dbl_increment(resultp1,resultp2);
}
case ROUNDZERO:;
}
if (Dbl_isone_hiddenoverflow(resultp1)) result_exponent++;
}
if (result_exponent >= DBL_INFINITY_EXPONENT) {
if (Is_overflowtrap_enabled()) {
Dbl_setwrapped_exponent(resultp1,result_exponent,ovfl);
Dbl_copytoptr(resultp1,resultp2,dstptr);
if (inexact)
if (Is_inexacttrap_enabled())
return (OPC_2E_OVERFLOWEXCEPTION |
OPC_2E_INEXACTEXCEPTION);
else Set_inexactflag();
return (OPC_2E_OVERFLOWEXCEPTION);
}
inexact = TRUE;
Set_overflowflag();
Dbl_setoverflow(resultp1,resultp2);
} else if (result_exponent <= 0) {
if (Is_underflowtrap_enabled()) {
Dbl_setwrapped_exponent(resultp1,result_exponent,unfl);
Dbl_copytoptr(resultp1,resultp2,dstptr);
if (inexact)
if (Is_inexacttrap_enabled())
return (OPC_2E_UNDERFLOWEXCEPTION |
OPC_2E_INEXACTEXCEPTION);
else Set_inexactflag();
return(OPC_2E_UNDERFLOWEXCEPTION);
}
else if (inexact && is_tiny) Set_underflowflag();
}
else Dbl_set_exponent(resultp1,result_exponent);
Dbl_copytoptr(resultp1,resultp2,dstptr);
if (inexact)
if (Is_inexacttrap_enabled()) return(OPC_2E_INEXACTEXCEPTION);
else Set_inexactflag();
return(NOEXCEPTION);
}