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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) 2021-2024 The DPS8M Development Team
13 *
14 * This software is made available under the terms of the ICU License.
15 * See the LICENSE.md file at the top-level directory of this distribution.
16 *
17 * ---------------------------------------------------------------------------
18 */
19
20 #include <stdio.h>
21
22 #include "dps8.h"
23 #include "dps8_sys.h"
24 #include "dps8_iom.h"
25 #include "dps8_cable.h"
26 #include "dps8_cpu.h"
27 #include "dps8_faults.h"
28 #include "dps8_scu.h"
29 #include "dps8_decimal.h"
30 #include "dps8_eis.h"
31 #include "dps8_utils.h"
32
33 /* ------------------------------------------------------------------ */
34 /* HWR 6/28/14 18:54 derived from ...... */
35 /* decContextDefault(...) */
36 /* */
37 /* decContextDefaultDPS8 -- initialize a context structure */
38 /* */
39 /* Similar to decContextDefault EXCEPT digits are set to 65 for our */
40 /* dps8 simulator (add additional features as required */
41 /* */
42 /* ------------------------------------------------------------------ */
43
44 decContext * decContextDefaultDPS8(decContext *context)
/* ![[next]](../icons/right.png)
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*/
45 {
46 decContextDefault(context, DEC_INIT_BASE);
47 context->traps=0;
48
49 context->digits = 65;
50
51 return context;
52 }
53
54 /* ------------------------------------------------------------------ */
55 /* HWR 3/21/16 19:54 derived from ...... */
56 /* decContextDefault(...) */
57 /* */
58 /* decContextDefaultDPS8 -- initialize a context structure */
59 /* */
60 /* Similar to decContextDefault EXCEPT digits are set to 126 for our */
61 /* dps8 simulators mpXd instructions */
62 /* */
63 /* ------------------------------------------------------------------ */
64
65 decContext * decContextDefaultDPS8Mul(decContext *context)
/* ![[previous]](../icons/left.png)
*/
66 {
67 decContextDefault(context, DEC_INIT_BASE);
68 context->traps = 0;
69
70 context->digits = 63 + 63; // worse case for multiply
71
72 return context;
73 }
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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
116 // leading zeros code wanders off the end of the input buffer....
117 for (first=bcd; *first==0 && first <= last;)
118 first++;
119
120 digits=(Int)(last-first)+1; // calculate digits ..
121 //if ((*first & 0xf0)==0) digits--; // adjust for leading zero nibble
122 if (digits!=0)
123 dn->digits=digits; // count of actual digits [if 0,
124 // leave as 1]
125
126 // check the adjusted exponent; note that scale could be unbounded
127 dn->exponent=-scale; // set the exponent
128 if (scale>=0) // usual case
129 {
130 if ((dn->digits-scale-1)<-DECNUMMAXE) // underflow
131 {
132 decNumberZero(dn);
133 //return NULL;
134 // XXX check subfault
135 doFault (FAULT_IPR, fst_ill_proc, "decBCD9ToNumber underflow");
136 }
137 }
138 else // -ve scale; +ve exponent
139 {
140 // need to be careful to avoid wrap, here, also BADINT case
141 if ((scale<-DECNUMMAXE) // overflow even without digits
142 || ((dn->digits-scale-1)>DECNUMMAXE)) // overflow
143 {
144 decNumberZero(dn);
145 //return NULL;
146 // XXX check subfault
147 doFault (FAULT_IPR, fst_ill_proc, "decBCD9ToNumber overflow");
148 }
149 }
150 if (digits==0)
151 return dn; // result was zero
152
153 // copy the digits to the number's units, starting at the lsu
154 // [unrolled]
155 for (;last >= bcd;) // forever
156 {
157 nib=(unsigned)(*last & 0x0f);
158 // got a digit, in nib
159 //if (nib>9) {decNumberZero(dn); return NULL;} // bad digit
160 if (nib > 9)
161 doFault (FAULT_IPR, fst_ill_dig, "decBCD9ToNumber ill digit");
162
163 if (cut==0)
164 *up=(Unit)nib;
165 else
166 *up=(Unit)(*up+nib*DECPOWERS[cut]);
167 digits--;
168 if (digits==0)
169 break; // got them all
170 cut++;
171 if (cut==DECDPUN)
172 {
173 up++;
174 cut=0;
175 }
176 last--; // ready for next
177
178 // nib = *last & 0x0f; // get right nibble
179 // if (nib>9) {decNumberZero(dn); return NULL;}
180 //
181 // // got a digit, in nib
182 // if (cut==0) *up=(Unit)nib;
183 // else *up=(Unit)(*up+nib*DECPOWERS[cut]);
184 // digits--;
185 // if (digits==0) break; // got them all
186 // cut++;
187 // if (cut==DECDPUN) {
188 // up++;
189 // cut=0;
190 // }
191 } // forever
192
193 return dn;
194 } // decBCD9ToNumber
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715 char *formatDecimal (uint8_t * out, decContext *set, decNumber *r, int nout, int s, int sf, bool R, bool *OVR, bool *TRUNC) {
/* */
716 decNumber _sf;
717 decNumber _r2;
718 decNumber * r2 = & _r2;
719 enum rounding safeR = decContextGetRounding (set); // save rounding mode
720 int safe = set->digits;
721
722 * OVR = false;
723 * TRUNC = false;
724
725 // CSFL isn't rescaled and can't overflow
726 if (s != CSFL) {
727 // rescale to sf first
728 // AL39: If N2 is not large enough to hold the integer part of C(Y-charn1) _as rescaled by SF2_, an overflow condition exists
729 // ET 336
730 if (sf != r->exponent) {
731 if (!R) {
732 decContextSetRounding (set, DEC_ROUND_DOWN); // Round towards 0 (truncation). ISOLTS 815 09b
733 if (sf > r->exponent) // ET 330: truncation due to: output sf > input sf or exponent
734 * TRUNC = true;
735 }
736 decNumberFromInt32 (& _sf, sf);
737
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749
750 if (r->exponent > sf)
751 set->digits = min (DECNUMDIGITS, max (set->digits, r->digits + r->exponent - sf));
752 decNumberRescale (r, r, & _sf, set);
753 if (decContextGetStatus (set) == DEC_Invalid_operation) {
754 //sim_debug (DBG_TRACE, & cpu_dev, "formatD DEC_Invalid_operation\r\n");
755 decNumberZero (r);
756 * OVR = true;
757 }
758 set->digits = safe;
759
760
761 }
762
763 // check for overflow and if it occurs, adjust the operand
764
765 decContextSetRounding (set, DEC_ROUND_DOWN); // Round towards 0 (truncation).
766 decNumberToIntegralValue (r2, r, set);
767
768 int r2digits = r2->digits;
769 if (decNumberIsZero (r2))
770 r2digits = 0;
771
772 // if sf< 0, this reduces number of integer slots available
773 // if sf>=0, this doesn't change anything, nout integer slots are available
774 // ET 275, ET 336
775 if (nout + min (sf,0) < r2digits) {
776 // discard overflowing digits
777 // note that this may set zero flag: ISOLTS-810 01l
778 set->digits = r2digits - (nout + min (sf,0));
779 decNumberPlus (r2, r, set);
780 set->digits = safe;
781
782 decNumberSubtract(r, r, r2, set);
783
784 * OVR = true;
785
786 }
787 decContextSetRounding (set, safeR);
788
789 }
790
791 if (nout < r->digits) { // not enough space to move all digits
792 // round or truncate
793 if (! R) {
794 decContextSetRounding(set, DEC_ROUND_DOWN); // Round towards 0 (truncation).
795 // truncation flag is independent of whether overflow occurred: ISOLTS-810 01k, 815 09b
796 * TRUNC = true;
797 }
798 set->digits = nout;
799 decNumberPlus (r, r, set);
800 set->digits = safe;
801
802 decContextSetRounding (set, safeR); // restore rounding mode
803 }
804
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808
809 // write out the digits
810 // note that even CSFL is aligned right - ISOLTS-810 05d
811 uint8_t tmp[256];
812 decNumberGetBCD (r,tmp);
813 int justif = nout - r->digits;
814 for (int i = 0; i < nout; i ++) {
815 if (i < justif)
816 out [i] = '0';
817 else
818 out [i] = tmp [i - justif] + '0';
819 }
820 out [nout] = 0;
821
822 return (char *) out;
823 }
824
825 #if !defined(QUIET_UNUSED)
826 // If the lhs is less than the rhs in the total order then the number
827 // will be set to the value -1. If they are equal, then number is set
828 // to 0. If the lhs is greater than the rhs then the number will be
829 // set to the value 1.
830 int decCompare(decNumber *lhs, decNumber *rhs, decContext *set)
/* */
831 {
832 decNumber _cmp, *cmp;
833 cmp = decNumberCompareTotal(&_cmp, lhs, rhs, set);
834
835 if (decNumberIsZero(cmp))
836 return 0; // lhs == rhs
837
838 if (decNumberIsNegative(cmp))
839 return -1; // lhs < rhs
840
841 return 1; // lhs > rhs
842 }
843 #endif /* if !defined(QUIET_UNUSED) */
844
845 int decCompareMAG(decNumber *lhs, decNumber *rhs, decContext *set)
/* ![[last]](../icons/n_last.png)
*/
846 {
847 decNumber _cmpm, *cmpm;
848 cmpm = decNumberCompareTotalMag(&_cmpm, lhs, rhs, set);
849
850 if (decNumberIsZero(cmpm))
851 return 0; // lhs == rhs
852
853 if (decNumberIsNegative(cmpm))
854 return -1; // lhs < rhs
855
856 return 1; // lhs > rhs
857 }
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*/