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*/
1 /*
2 * vim: filetype=c:tabstop=4:ai:expandtab
3 * SPDX-License-Identifier: ICU
4 * scspell-id: 9868415b-f62d-11ec-9c75-80ee73e9b8e7
5 *
6 * ---------------------------------------------------------------------------
7 *
8 * Copyright (c) 2000-2009 IBM Corporation
9 * Copyright (c) 2012-2016 Harry Reed
10 * Copyright (c) 2013-2016 Charles Anthony
11 * Copyright (c) 2017 Michal Tomek
12 * Copyright (c) 2021-2022 The DPS8M Development Team
13 *
14 * All rights reserved.
15 *
16 * This software is made available under the terms of the ICU
17 * License, version 1.8.1 or later. For more details, see the
18 * LICENSE.md file at the top-level directory of this distribution.
19 *
20 * ---------------------------------------------------------------------------
21 */
22
23 #include <stdio.h>
24
25 #include "dps8.h"
26 #include "dps8_sys.h"
27 #include "dps8_faults.h"
28 #include "dps8_scu.h"
29 #include "dps8_iom.h"
30 #include "dps8_cable.h"
31 #include "dps8_cpu.h"
32 #include "dps8_decimal.h"
33 #include "dps8_eis.h"
34 #include "dps8_utils.h"
35
36 /* ------------------------------------------------------------------ */
37 /* HWR 6/28/14 18:54 derived from ...... */
38 /* decContextDefault(...) */
39 /* */
40 /* decContextDefaultDPS8 -- initialize a context structure */
41 /* */
42 /* Similar to decContextDefault EXCEPT digits are set to 65 for our */
43 /* dps8 simulator (add additional features as required */
44 /* */
45 /* ------------------------------------------------------------------ */
46 decContext * decContextDefaultDPS8(decContext *context)
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*/
47 {
48 decContextDefault(context, DEC_INIT_BASE);
49 context->traps=0;
50
51 context->digits = 65;
52
53 return context;
54 }
55
56 /* ------------------------------------------------------------------ */
57 /* HWR 3/21/16 19:54 derived from ...... */
58 /* decContextDefault(...) */
59 /* */
60 /* decContextDefaultDPS8 -- initialize a context structure */
61 /* */
62 /* Similar to decContextDefault EXCEPT digits are set to 126 for our */
63 /* dps8 simulators mpXd instructions */
64 /* */
65 /* ------------------------------------------------------------------ */
66 decContext * decContextDefaultDPS8Mul(decContext *context)
/* ![[previous]](../icons/left.png)
*/
67 {
68 decContextDefault(context, DEC_INIT_BASE);
69 context->traps = 0;
70
71 context->digits = 63 + 63; // worse case for multiply
72
73 return context;
74 }
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97 decNumber * decBCD9ToNumber(const word9 *bcd, Int length, const Int scale, decNumber *dn)
/* */
98 {
99 const word9 *last=bcd+length-1; // -> last byte
100 const word9 *first; // -> first non-zero byte
101 uInt nib; // work nibble
102 Unit *up=dn->lsu; // output pointer
103 Int digits; // digits count
104 Int cut=0; // phase of output
105
106 decNumberZero(dn); // default result
107 //last = &bcd[length-1];
108 //nib = *last & 0x0f; // get the sign
109 //if (nib==DECPMINUS || nib==DECPMINUSALT) dn->bits=DECNEG;
110 //else if (nib<=9) return NULL; // not a sign nibble
111
112 // skip leading zero bytes [final byte is always non-zero, due to sign]
113 //for (first=bcd; *first==0;) first++;
114
115 //Also, a bug in decBCD9ToNumber; in the input is all zeros, the skip leading zeros code wanders off the end of the input buffer....
116 for (first=bcd; *first==0 && first <= last;)
117 first++;
118
119 digits=(Int)(last-first)+1; // calculate digits ..
120 //if ((*first & 0xf0)==0) digits--; // adjust for leading zero nibble
121 if (digits!=0)
122 dn->digits=digits; // count of actual digits [if 0,
123 // leave as 1]
124
125 // check the adjusted exponent; note that scale could be unbounded
126 dn->exponent=-scale; // set the exponent
127 if (scale>=0) // usual case
128 {
129 if ((dn->digits-scale-1)<-DECNUMMAXE) // underflow
130 {
131 decNumberZero(dn);
132 //return NULL;
133 // XXX check subfault
134 doFault (FAULT_IPR, fst_ill_proc, "decBCD9ToNumber underflow");
135 }
136 }
137 else // -ve scale; +ve exponent
138 {
139 // need to be careful to avoid wrap, here, also BADINT case
140 if ((scale<-DECNUMMAXE) // overflow even without digits
141 || ((dn->digits-scale-1)>DECNUMMAXE)) // overflow
142 {
143 decNumberZero(dn);
144 //return NULL;
145 // XXX check subfault
146 doFault (FAULT_IPR, fst_ill_proc, "decBCD9ToNumber overflow");
147 }
148 }
149 if (digits==0)
150 return dn; // result was zero
151
152 // copy the digits to the number's units, starting at the lsu
153 // [unrolled]
154 for (;last >= bcd;) // forever
155 {
156 nib=(unsigned)(*last & 0x0f);
157 // got a digit, in nib
158 //if (nib>9) {decNumberZero(dn); return NULL;} // bad digit
159 if (nib > 9)
160 doFault (FAULT_IPR, fst_ill_dig, "decBCD9ToNumber ill digit");
161
162 if (cut==0)
163 *up=(Unit)nib;
164 else
165 *up=(Unit)(*up+nib*DECPOWERS[cut]);
166 digits--;
167 if (digits==0)
168 break; // got them all
169 cut++;
170 if (cut==DECDPUN)
171 {
172 up++;
173 cut=0;
174 }
175 last--; // ready for next
176
177 // nib = *last & 0x0f; // get right nibble
178 // if (nib>9) {decNumberZero(dn); return NULL;}
179 //
180 // // got a digit, in nib
181 // if (cut==0) *up=(Unit)nib;
182 // else *up=(Unit)(*up+nib*DECPOWERS[cut]);
183 // digits--;
184 // if (digits==0) break; // got them all
185 // cut++;
186 // if (cut==DECDPUN) {
187 // up++;
188 // cut=0;
189 // }
190 } // forever
191
192 return dn;
193 } // decBCD9ToNumber
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705 char *formatDecimal (uint8_t * out, decContext *set, decNumber *r, int nout, int s, int sf, bool R, bool *OVR, bool *TRUNC) {
/* */
706 decNumber _sf;
707 decNumber _r2;
708 decNumber * r2 = & _r2;
709 enum rounding safeR = decContextGetRounding (set); // save rounding mode
710 int safe = set->digits;
711
712 * OVR = false;
713 * TRUNC = false;
714
715 // CSFL isn't rescaled and can't overflow
716 if (s != CSFL) {
717
718 // rescale to sf first
719 // AL39: If N2 is not large enough to hold the integer part of C(Y-charn1) _as rescaled by SF2_, an overflow condition exists
720 // ET 336
721 if (sf != r->exponent) {
722 if (!R) {
723 decContextSetRounding (set, DEC_ROUND_DOWN); // Round towards 0 (truncation). ISOLTS 815 09b
724 if (sf > r->exponent) // ET 330: truncation due to: output sf > input sf or exponent
725 * TRUNC = true;
726 }
727 decNumberFromInt32 (& _sf, sf);
728
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741 if (r->exponent > sf)
742 set->digits = min (DECNUMDIGITS, max (set->digits, r->digits + r->exponent - sf));
743 decNumberRescale (r, r, & _sf, set);
744 if (decContextGetStatus (set) == DEC_Invalid_operation) {
745 //sim_debug (DBG_TRACE, & cpu_dev, "formatD DEC_Invalid_operation\r\n");
746 decNumberZero (r);
747 * OVR = true;
748 }
749 set->digits = safe;
750
751
752 }
753
754 // check for overflow and if it occurs, adjust the operand
755
756 decContextSetRounding (set, DEC_ROUND_DOWN); // Round towards 0 (truncation).
757 decNumberToIntegralValue (r2, r, set);
758
759 int r2digits = r2->digits;
760 if (decNumberIsZero (r2))
761 r2digits = 0;
762
763 // if sf< 0, this reduces number of integer slots available
764 // if sf>=0, this doesn't change anything, nout integer slots are available
765 // ET 275, ET 336
766 if (nout + min (sf,0) < r2digits) {
767
768 // discard overflowing digits
769 // note that this may set zero flag: ISOLTS-810 01l
770 set->digits = r2digits - (nout + min (sf,0));
771 decNumberPlus (r2, r, set);
772 set->digits = safe;
773
774 decNumberSubtract(r, r, r2, set);
775
776 * OVR = true;
777
778 }
779 decContextSetRounding (set, safeR);
780
781 }
782
783 if (nout < r->digits) { // not enough space to move all digits
784 // round or truncate
785 if (! R) {
786 decContextSetRounding(set, DEC_ROUND_DOWN); // Round towards 0 (truncation).
787 // truncation flag is independent of whether overflow occurred: ISOLTS-810 01k, 815 09b
788 * TRUNC = true;
789 }
790 set->digits = nout;
791 decNumberPlus (r, r, set);
792 set->digits = safe;
793
794 decContextSetRounding (set, safeR); // restore rounding mode
795 }
796
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799
800
801 // write out the digits
802 // note that even CSFL is aligned right - ISOLTS-810 05d
803 uint8_t tmp[256];
804 decNumberGetBCD (r,tmp);
805 int justif = nout - r->digits;
806 for (int i = 0; i < nout; i ++) {
807 if (i < justif)
808 out [i] = '0';
809 else
810 out [i] = tmp [i - justif] + '0';
811 }
812 out [nout] = 0;
813
814 return (char *) out;
815 }
816
817 #ifndef QUIET_UNUSED
818 // If the lhs is less than the rhs in the total order then the number
819 // will be set to the value -1. If they are equal, then number is set
820 // to 0. If the lhs is greater than the rhs then the number will be
821 // set to the value 1.
822 int decCompare(decNumber *lhs, decNumber *rhs, decContext *set)
/* */
823 {
824 decNumber _cmp, *cmp;
825 cmp = decNumberCompareTotal(&_cmp, lhs, rhs, set);
826
827 if (decNumberIsZero(cmp))
828 return 0; // lhs == rhs
829
830 if (decNumberIsNegative(cmp))
831 return -1; // lhs < rhs
832
833 return 1; // lhs > rhs
834 }
835 #endif
836
837 int decCompareMAG(decNumber *lhs, decNumber *rhs, decContext *set)
/* ![[last]](../icons/n_last.png)
*/
838 {
839 decNumber _cmpm, *cmpm;
840 cmpm = decNumberCompareTotalMag(&_cmpm, lhs, rhs, set);
841
842 if (decNumberIsZero(cmpm))
843 return 0; // lhs == rhs
844
845 if (decNumberIsNegative(cmpm))
846 return -1; // lhs < rhs
847
848 return 1; // lhs > rhs
849 }
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![[bottom]](../icons/n_bottom.png){kind=icon}
*/