ba237a9d91
Files correlati : Ricompilazione Demo : [ ] Commento : Aggiunti i sorgenti per Greenleaf Math Library (gfm.dll) git-svn-id: svn://10.65.10.50/trunk@10079 c028cbd2-c16b-5b4b-a496-9718f37d4682
120 lines
2.6 KiB
C
Executable File
120 lines
2.6 KiB
C
Executable File
/* int _SubDec80Bit(pDst,pSrc1,pSrc2)
|
|
*
|
|
* ARGUMENT
|
|
* pDst is a pointer to the destination DEC structure.
|
|
* pSrc1 is a ptr to the source1 DEC structure.
|
|
* pSrc2 is a ptr to the source2 DEC structure.
|
|
*
|
|
* DESCRIPTION
|
|
* Subtracts the value in pSrc2 from the value in pSrc1
|
|
* and puts the result in pDst DEC structure. The difference is calculated
|
|
* to the maximum possible accuracy.
|
|
*
|
|
* SIDE EFFECTS
|
|
* On overflow, the dest value is indeterminate.
|
|
*
|
|
* RETURNS
|
|
* Returns GM_SUCCESS unless an error, in which case the specific
|
|
* error code is returned.
|
|
*
|
|
* Note: uses an assembly language routine for the actual math
|
|
*
|
|
* AUTHOR
|
|
* Andy Anderson 13-JUL-87
|
|
* Copyright (C) 1987-1990 Greenleaf Software Inc. All rights reserved.
|
|
*
|
|
* MODIFICATIONS
|
|
*
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include "gm.h"
|
|
#include "gmsystem.h"
|
|
|
|
int _SubDec80Bit(pDst,pSrc1,pSrc2)
|
|
DEC *pDst;
|
|
DEC *pSrc1,*pSrc2;
|
|
{
|
|
DEC t1, t2, *pts;
|
|
register int i,j;
|
|
int s1, s2;
|
|
|
|
/* if the source id's are different, make them equal with as much accuracy
|
|
as is possible, and protect source fields from change */
|
|
|
|
/* line up decimal places */
|
|
i = pSrc1->dc.id-pSrc2->dc.id;
|
|
if (i) {
|
|
pts = &t1;
|
|
_MacDCopy(pts, pSrc1);
|
|
pts = &t2;
|
|
_MacDCopy(pts, pSrc2);
|
|
_MacDChgs(pts);
|
|
|
|
if (i<0) {
|
|
pSrc1 = &t1;
|
|
pSrc2 = &t2;
|
|
i = -i;
|
|
}
|
|
else {
|
|
pSrc2 = &t1;
|
|
pSrc1 = &t2;
|
|
}
|
|
|
|
j = _MulUnsArrByPwrOf10Limited(
|
|
pSrc1->dc.sl, i, 5);
|
|
pSrc1->dc.id += j;
|
|
if (j<i)
|
|
_DivUnsArrByPwrOf10(pSrc2->dc.sl, 5, i-j);
|
|
}
|
|
|
|
s1 = pSrc1->dc.attr & 0x0001;
|
|
s2 = pSrc2->dc.attr & 0x0001;
|
|
if (i==0)
|
|
s2=1-s2;
|
|
|
|
/* Subtract the numbers */
|
|
pDst->dc.id = pSrc1->dc.id;
|
|
|
|
if (s1 == s2) {
|
|
/* Add absolute values if signs are equal */
|
|
_AddUnsArrToUnsArr(pSrc1->dc.sl, pSrc2->dc.sl,
|
|
pDst->dc.sl,5);
|
|
|
|
/* if the first addition is an overflow, round down and try again */
|
|
if (pDst->dc.sl[3] >= 32768L) {
|
|
if (pSrc1->dc.id <= GM_IMINID)
|
|
return(GM_OVERFLOW);
|
|
_DivUnsArrByUns(pDst->dc.sl, 10, 5);
|
|
pDst->dc.id--;
|
|
}
|
|
|
|
/* sign of pDst same as sign of sources */
|
|
pDst->dc.attr = s1;
|
|
}
|
|
|
|
else {
|
|
/* subtract larger absolute value from smaller if signs are different */
|
|
if (_CompareUnsArr(pSrc1->dc.sl,
|
|
pSrc2->dc.sl, 5) >= 0) {
|
|
/* pSrc1 has larger absolute value */
|
|
(void) _SubUnsArrFromUnsArr(pSrc1->dc.sl,
|
|
pSrc2->dc.sl,
|
|
pDst->dc.sl,5);
|
|
/* sum has same sign as pSrc1 */
|
|
pDst->dc.attr = s1;
|
|
}
|
|
|
|
else {
|
|
/* pSrc2 has larger absolute value */
|
|
(void) _SubUnsArrFromUnsArr(pSrc2->dc.sl,
|
|
pSrc1->dc.sl,
|
|
pDst->dc.sl,5);
|
|
/* sum has same sign as pSrc2 */
|
|
pDst->dc.attr = s2;
|
|
}
|
|
}
|
|
|
|
return(GM_SUCCESS);
|
|
}
|