4 conversions and numerical operations for the c# type System.Decimal
6 Author: Martin Weindel (martin.weindel@t-online.de)
8 (C) 2001 by Martin Weindel
12 * machine dependent configuration for
13 * CSharp value type System.Decimal
22 /* needed for building microsoft dll */
23 #define DECINLINE __inline
25 #define LIT_GUINT32(x) x
26 #define LIT_GUINT64(x) x##L
29 /* we need a UInt64 type => guint64 */
35 * Deal with anon union support.
38 #define signscale u.signscale
43 #define PRECONDITION(flag) assert(flag)
44 #define POSTCONDITION(flag) assert(flag)
45 #define TEST(flag) assert(flag)
46 #define INVARIANT_TEST(p) assert(p->signscale.scale >= 0 && p->signscale.scale <= DECIMAL_MAX_SCALE \
47 && p->signscale.reserved1 == 0 && p->signscale.reserved2 == 0);
49 #define PRECONDITION(flag)
50 #define POSTCONDITION(flag)
52 #define INVARIANT_TEST(p)
53 #endif /*#ifdef _DEBUG*/
55 #define DECIMAL_MAX_SCALE 28
56 #define DECIMAL_MAX_INTFACTORS 9
58 #define DECIMAL_SUCCESS 0
59 #define DECIMAL_FINISHED 1
60 #define DECIMAL_OVERFLOW 2
61 #define DECIMAL_INVALID_CHARACTER 2
62 #define DECIMAL_INTERNAL_ERROR 3
63 #define DECIMAL_INVALID_BITS 4
64 #define DECIMAL_DIVIDE_BY_ZERO 5
65 #define DECIMAL_BUFFER_OVERFLOW 6
68 #define DECINIT(src) memset(src, 0, sizeof(decimal_repr))
70 #define DECCOPY(dest, src) memcpy(dest, src, sizeof(decimal_repr))
72 #define DECSWAP(p1, p2, h) \
73 h = (p1)->ss32; (p1)->ss32 = (p2)->ss32; (p2)->ss32 = h; \
74 h = (p1)->hi32; (p1)->hi32 = (p2)->hi32; (p2)->hi32 = h; \
75 h = (p1)->mid32; (p1)->mid32 = (p2)->mid32; (p2)->mid32 = h; \
76 h = (p1)->lo32; (p1)->lo32 = (p2)->lo32; (p2)->lo32 = h;
78 #define DECNEGATE(p1) (p1)->signscale.sign = 1 - (p1)->signscale.sign
80 #define LIT_DEC128(hi, mid, lo) { (((guint64)mid)<<32 | lo), hi }
82 #define DECTO128(pd, lo, hi) \
83 lo = (((guint64)(pd)->mid32) << 32) | (pd)->lo32; \
87 #define LIT_GUINT32_HIGHBIT LIT_GUINT32(0x80000000)
88 #define LIT_GUINT64_HIGHBIT LIT_GUINT64(0x8000000000000000)
90 #define DECIMAL_LOG_NEGINF -1000
92 static guint32 constantsDecadeInt32Factors[DECIMAL_MAX_INTFACTORS+1] = {
93 LIT_GUINT32(1), LIT_GUINT32(10), LIT_GUINT32(100), LIT_GUINT32(1000),
94 LIT_GUINT32(10000), LIT_GUINT32(100000), LIT_GUINT32(1000000),
95 LIT_GUINT32(10000000), LIT_GUINT32(100000000), LIT_GUINT32(1000000000)
103 static dec128_repr dec128decadeFactors[DECIMAL_MAX_SCALE+1] = {
104 LIT_DEC128( 0, 0, 1u), /* == 1 */
105 LIT_DEC128( 0, 0, 10u), /* == 10 */
106 LIT_DEC128( 0, 0, 100u), /* == 100 */
107 LIT_DEC128( 0, 0, 1000u), /* == 1e3m */
108 LIT_DEC128( 0, 0, 10000u), /* == 1e4m */
109 LIT_DEC128( 0, 0, 100000u), /* == 1e5m */
110 LIT_DEC128( 0, 0, 1000000u), /* == 1e6m */
111 LIT_DEC128( 0, 0, 10000000u), /* == 1e7m */
112 LIT_DEC128( 0, 0, 100000000u), /* == 1e8m */
113 LIT_DEC128( 0, 0, 1000000000u), /* == 1e9m */
114 LIT_DEC128( 0, 2u, 1410065408u), /* == 1e10m */
115 LIT_DEC128( 0, 23u, 1215752192u), /* == 1e11m */
116 LIT_DEC128( 0, 232u, 3567587328u), /* == 1e12m */
117 LIT_DEC128( 0, 2328u, 1316134912u), /* == 1e13m */
118 LIT_DEC128( 0, 23283u, 276447232u), /* == 1e14m */
119 LIT_DEC128( 0, 232830u, 2764472320u), /* == 1e15m */
120 LIT_DEC128( 0, 2328306u, 1874919424u), /* == 1e16m */
121 LIT_DEC128( 0, 23283064u, 1569325056u), /* == 1e17m */
122 LIT_DEC128( 0, 232830643u, 2808348672u), /* == 1e18m */
123 LIT_DEC128( 0, 2328306436u, 2313682944u), /* == 1e19m */
124 LIT_DEC128( 5u, 1808227885u, 1661992960u), /* == 1e20m */
125 LIT_DEC128( 54u, 902409669u, 3735027712u), /* == 1e21m */
126 LIT_DEC128( 542u, 434162106u, 2990538752u), /* == 1e22m */
127 LIT_DEC128( 5421u, 46653770u, 4135583744u), /* == 1e23m */
128 LIT_DEC128( 54210u, 466537709u, 2701131776u), /* == 1e24m */
129 LIT_DEC128( 542101u, 370409800u, 1241513984u), /* == 1e25m */
130 LIT_DEC128( 5421010u, 3704098002u, 3825205248u), /* == 1e26m */
131 LIT_DEC128( 54210108u, 2681241660u, 3892314112u), /* == 1e27m */
132 LIT_DEC128( 542101086u, 1042612833u, 268435456u), /* == 1e28m */
135 /* 192 bit addition: c = a + b
136 addition is modulo 2**128, any carry is lost */
137 DECINLINE static void add128(guint64 alo, guint64 ahi,
138 guint64 blo, guint64 bhi,
139 guint64* pclo, guint64* pchi)
142 if (alo < blo) ahi++; /* carry */
149 /* 128 bit subtraction: c = a - b
150 subtraction is modulo 2**128, any carry is lost */
151 DECINLINE static void sub128(guint64 alo, guint64 ahi,
152 guint64 blo, guint64 bhi,
153 guint64* pclo, guint64* pchi)
159 if (alo < blo) chi--; /* borrow */
165 /* 192 bit addition: c = a + b
166 addition is modulo 2**192, any carry is lost */
167 DECINLINE static void add192(guint64 alo, guint64 ami, guint64 ahi,
168 guint64 blo, guint64 bmi, guint64 bhi,
169 guint64* pclo, guint64* pcmi, guint64* pchi)
172 if (alo < blo) { /* carry low */
174 if (ami == 0) ahi++; /* carry mid */
177 if (ami < bmi) ahi++; /* carry mid */
184 /* 192 bit subtraction: c = a - b
185 subtraction is modulo 2**192, any carry is lost */
186 DECINLINE static void sub192(guint64 alo, guint64 ami, guint64 ahi,
187 guint64 blo, guint64 bmi, guint64 bhi,
188 guint64* pclo, guint64* pcmi, guint64* pchi)
190 guint64 clo, cmi, chi;
196 if (cmi == 0) chi--; /* borrow mid */
197 cmi--; /* borrow low */
199 if (ami < bmi) chi--; /* borrow mid */
205 /* multiplication c(192bit) = a(96bit) * b(96bit) */
206 DECINLINE static void mult96by96to192(guint32 alo, guint32 ami, guint32 ahi,
207 guint32 blo, guint32 bmi, guint32 bhi,
208 guint64* pclo, guint64* pcmi, guint64* pchi)
211 guint32 h0, h1, h2, h3, h4, h5;
214 a = ((guint64)alo) * blo;
217 a >>= 32; carry0 = 0;
218 b = ((guint64)alo) * bmi;
219 c = ((guint64)ami) * blo;
220 a += b; if (a < b) carry0++;
221 a += c; if (a < c) carry0++;
224 a >>= 32; carry1 = 0;
225 b = ((guint64)alo) * bhi;
226 c = ((guint64)ami) * bmi;
227 d = ((guint64)ahi) * blo;
228 a += b; if (a < b) carry1++;
229 a += c; if (a < c) carry1++;
230 a += d; if (a < d) carry1++;
233 a >>= 32; a += carry0; carry0 = 0;
234 b = ((guint64)ami) * bhi;
235 c = ((guint64)ahi) * bmi;
236 a += b; if (a < b) carry0++;
237 a += c; if (a < c) carry0++;
240 a >>= 32; a += carry1;
241 b = ((guint64)ahi) * bhi;
245 a >>= 32; a += carry0;
248 *pclo = ((guint64)h1) << 32 | h0;
249 *pcmi = ((guint64)h3) << 32 | h2;
250 *pchi = ((guint64)h5) << 32 | h4;
253 /* multiplication c(128bit) = a(96bit) * b(32bit) */
254 DECINLINE static void mult96by32to128(guint32 alo, guint32 ami, guint32 ahi,
256 guint64* pclo, guint64* pchi)
261 a = ((guint64)alo) * factor;
265 a += ((guint64)ami) * factor;
269 a += ((guint64)ahi) * factor;
271 *pclo = ((guint64)h1) << 32 | h0;
275 /* multiplication c(128bit) *= b(32bit) */
276 DECINLINE static int mult128by32(guint64* pclo, guint64* pchi, guint32 factor, int roundBit)
281 a = ((guint64)(guint32)(*pclo)) * factor;
282 if (roundBit) a += factor / 2;
286 a += (*pclo >> 32) * factor;
289 *pclo = ((guint64)h1) << 32 | h0;
292 a += ((guint64)(guint32)(*pchi)) * factor;
296 a += (*pchi >> 32) * factor;
299 *pchi = ((guint64)h1) << 32 | h0;
301 return ((a >> 32) == 0) ? DECIMAL_SUCCESS : DECIMAL_OVERFLOW;
304 DECINLINE static int mult128DecadeFactor(guint64* pclo, guint64* pchi, int powerOfTen)
308 while (powerOfTen > 0) {
309 idx = (powerOfTen >= DECIMAL_MAX_INTFACTORS) ? DECIMAL_MAX_INTFACTORS : powerOfTen;
311 rc = mult128by32(pclo, pchi, constantsDecadeInt32Factors[idx], 0);
312 if (rc != DECIMAL_SUCCESS) return rc;
314 return DECIMAL_SUCCESS;
317 /* division: x(128bit) /= factor(32bit)
319 DECINLINE static int div128by32(guint64* plo, guint64* phi, guint32 factor, guint32* pRest)
324 a = (guint32)(h >> 32);
332 *phi = b << 32 | (guint32)c;
335 a |= (guint32)(h >> 32);
342 *plo = b << 32 | (guint32)c;
344 if (pRest) *pRest = (guint32) a;
347 return (a > factor || (a == factor && (c & 1) == 1)) ? 1 : 0;
350 /* division: x(192bit) /= factor(32bit)
351 no rest and no rounding*/
352 DECINLINE static void div192by32(guint64* plo, guint64* pmi, guint64* phi,
358 a = (guint32)(h >> 32);
366 *phi = b << 32 | (guint32)c;
369 a |= (guint32)(h >> 32);
377 *pmi = b << 32 | (guint32)c;
380 a |= (guint32)(h >> 32);
388 *plo = b << 32 | (guint32)c;
391 /* returns upper 32bit for a(192bit) /= b(32bit)
392 a will contain remainder */
393 static guint32 div192by96to32withRest(guint64* palo, guint64* pami, guint64* pahi,
394 guint32 blo, guint32 bmi, guint32 bhi)
396 guint64 rlo, rmi, rhi; /* remainder */
397 guint64 tlo, thi; /* term */
400 rlo = *palo; rmi = *pami; rhi = *pahi;
401 if (rhi >= (((guint64)bhi) << 32)) {
402 c = LIT_GUINT32(0xFFFFFFFF);
404 c = (guint32) (rhi / bhi);
406 mult96by32to128(blo, bmi, bhi, c, &tlo, &thi);
407 sub192(rlo, rmi, rhi, 0, tlo, thi, &rlo, &rmi, &rhi);
408 while (((gint64)rhi) < 0) {
410 add192(rlo, rmi, rhi, 0, (((guint64)bmi)<<32) | blo, bhi, &rlo, &rmi, &rhi);
412 *palo = rlo ; *pami = rmi ; *pahi = rhi;
414 POSTCONDITION(rhi >> 32 == 0);
419 /* c(128bit) = a(192bit) / b(96bit)
421 static void div192by96to128(guint64 alo, guint64 ami, guint64 ahi,
422 guint32 blo, guint32 bmi, guint32 bhi,
423 guint64* pclo, guint64* pchi)
425 guint64 rlo, rmi, rhi; /* remainder */
428 PRECONDITION(ahi < (((guint64)bhi) << 32 | bmi)
429 || (ahi == (((guint64)bhi) << 32 | bmi) && (ami >> 32) > blo));
432 rlo = alo; rmi = ami; rhi = ahi;
433 h = div192by96to32withRest(&rlo, &rmi, &rhi, blo, bmi, bhi);
436 rhi = (rhi << 32) | (rmi >> 32); rmi = (rmi << 32) | (rlo >> 32); rlo <<= 32;
437 *pchi = (((guint64)h) << 32) | div192by96to32withRest(&rlo, &rmi, &rhi, blo, bmi, bhi);
440 rhi = (rhi << 32) | (rmi >> 32); rmi = (rmi << 32) | (rlo >> 32); rlo <<= 32;
441 h = div192by96to32withRest(&rlo, &rmi, &rhi, blo, bmi, bhi);
443 /* estimate lowest 32 bit (two last bits may be wrong) */
445 c = LIT_GUINT32(0xFFFFFFFF);
448 c = (guint32) (rhi / bhi);
450 *pclo = (((guint64)h) << 32) | c;
453 DECINLINE static void roundUp128(guint64* pclo, guint64* pchi) {
454 if (++(*pclo) == 0) ++(*pchi);
457 static int normalize128(guint64* pclo, guint64* pchi, int* pScale,
458 int roundFlag, int roundBit)
460 guint32 overhang = (guint32)(*pchi >> 32);
464 while (overhang != 0) {
465 for (deltaScale = 1; deltaScale < DECIMAL_MAX_INTFACTORS; deltaScale++)
467 if (overhang < constantsDecadeInt32Factors[deltaScale]) break;
471 if (scale < 0) return DECIMAL_OVERFLOW;
473 roundBit = div128by32(pclo, pchi, constantsDecadeInt32Factors[deltaScale], 0);
475 overhang = (guint32)(*pchi >> 32);
476 if (roundFlag && roundBit && *pclo == (guint64)-1 && (gint32)*pchi == (gint32)-1) {
483 if (roundFlag && roundBit) {
484 roundUp128(pclo, pchi);
485 TEST((*pchi >> 32) == 0);
488 return DECIMAL_SUCCESS;
491 DECINLINE static int maxLeftShift(/*[In, Out]*/decimal_repr* pA)
493 guint64 lo64 = (((guint64)(pA->mid32)) << 32) | pA->lo32;
494 guint32 hi32 = pA->hi32;
497 for (shift = 0; ((gint32)hi32) >= 0 && shift < 96; shift++) {
499 if (((gint64)lo64) < 0) hi32++;
503 pA->lo32 = (guint32) lo64;
504 pA->mid32 = (guint32)(lo64>>32);
510 DECINLINE static void rshift128(guint64* pclo, guint64* pchi)
513 if (*pchi & 1) *pclo |= LIT_GUINT64_HIGHBIT;
517 DECINLINE static void lshift96(guint32* pclo, guint32* pcmid, guint32* pchi)
520 if (*pcmid & LIT_GUINT32_HIGHBIT) (*pchi)++;
522 if (*pclo & LIT_GUINT32_HIGHBIT) (*pcmid)++;
526 DECINLINE static void lshift128(guint64* pclo, guint64* pchi)
529 if (*pclo & LIT_GUINT64_HIGHBIT) (*pchi)++;
533 DECINLINE static void rshift192(guint64* pclo, guint64* pcmi, guint64* pchi)
536 if (*pcmi & 1) *pclo |= LIT_GUINT64_HIGHBIT;
538 if (*pchi & 1) *pcmi |= LIT_GUINT64_HIGHBIT;
542 /* returns log2(a) or DECIMAL_LOG_NEGINF for a = 0 */
543 DECINLINE static int log2_32(guint32 a)
547 if (a == 0) return DECIMAL_LOG_NEGINF;
549 if ((a >> 16) != 0) {
574 /* returns log2(a) or DECIMAL_LOG_NEGINF for a = 0 */
575 DECINLINE static int log2_64(guint64 a)
579 if (a == 0) return DECIMAL_LOG_NEGINF;
581 if ((a >> 32) != 0) {
585 if ((a >> 16) != 0) {
610 /* returns log2(a) or DECIMAL_LOG_NEGINF for a = 0 */
611 DECINLINE static int log2_128(guint64 alo, guint64 ahi)
613 if (ahi == 0) return log2_64(alo);
614 else return log2_64(ahi) + 64;
617 /* returns a upper limit for log2(a) considering scale */
618 DECINLINE static int log2withScale_128(guint64 alo, guint64 ahi, int scale)
620 int tlog2 = log2_128(alo, ahi);
621 if (tlog2 < 0) tlog2 = 0;
622 return tlog2 - (scale * 33219) / 10000;
625 DECINLINE static int pack128toDecimal(/*[Out]*/decimal_repr* pA, guint64 alo, guint64 ahi,
628 PRECONDITION((ahi >> 32) == 0);
629 PRECONDITION(sign == 0 || sign == 1);
630 PRECONDITION(scale >= 0 && scale <= DECIMAL_MAX_SCALE);
632 if (scale < 0 || scale > DECIMAL_MAX_SCALE || (ahi >> 32) != 0) {
633 return DECIMAL_OVERFLOW;
636 pA->lo32 = (guint32) alo;
637 pA->mid32 = (guint32) (alo >> 32);
638 pA->hi32 = (guint32) ahi;
639 pA->signscale.sign = sign;
640 pA->signscale.scale = scale;
642 return DECIMAL_SUCCESS;
645 DECINLINE static int adjustScale128(guint64* palo, guint64* pahi, int deltaScale)
649 if (deltaScale < 0) {
651 if (deltaScale > DECIMAL_MAX_SCALE) return DECIMAL_INTERNAL_ERROR;
652 while (deltaScale > 0) {
653 idx = (deltaScale > DECIMAL_MAX_INTFACTORS) ? DECIMAL_MAX_INTFACTORS : deltaScale;
655 div128by32(palo, pahi, constantsDecadeInt32Factors[idx], 0);
657 } else if (deltaScale > 0) {
658 if (deltaScale > DECIMAL_MAX_SCALE) return DECIMAL_INTERNAL_ERROR;
659 while (deltaScale > 0) {
660 idx = (deltaScale > DECIMAL_MAX_INTFACTORS) ? DECIMAL_MAX_INTFACTORS : deltaScale;
662 rc = mult128by32(palo, pahi, constantsDecadeInt32Factors[idx], 0);
663 if (rc != DECIMAL_SUCCESS) return rc;
667 return DECIMAL_SUCCESS;
670 /* input: c * 10^-(*pScale) * 2^-exp
671 output: c * 10^-(*pScale) with
672 minScale <= *pScale <= maxScale and (chi >> 32) == 0 */
673 DECINLINE static int rescale128(guint64* pclo, guint64* pchi, int* pScale, int texp,
674 int minScale, int maxScale, int roundFlag)
676 guint32 factor, overhang;
677 int scale, i, rc, roundBit = 0;
679 PRECONDITION(texp >= 0);
685 while (texp > 0 && scale <= maxScale) {
686 overhang = (guint32)(*pchi >> 32);
687 while (texp > 0 && ((*pclo & 1) == 0 || overhang > (2<<DECIMAL_MAX_INTFACTORS))) {
688 if (--texp == 0) roundBit = (int)(*pclo & 1);
689 rshift128(pclo, pchi);
690 overhang = (guint32)(*pchi >> 32);
693 if (texp > DECIMAL_MAX_INTFACTORS) i = DECIMAL_MAX_INTFACTORS;
695 if (scale + i > maxScale) i = maxScale - scale;
699 factor = constantsDecadeInt32Factors[i] >> i; /* 10^i/2^i=5^i */
700 mult128by32(pclo, pchi, factor, 0);
701 /*printf("3: %.17e\n", (((double)chi) * pow(2,64) + clo) * pow(10, -scale) * pow(2, -texp));*/
705 if (--texp == 0) roundBit = (int)(*pclo & 1);
706 rshift128(pclo, pchi);
712 while (scale > maxScale) {
713 i = scale - maxScale;
714 if (i > DECIMAL_MAX_INTFACTORS) i = DECIMAL_MAX_INTFACTORS;
716 roundBit = div128by32(pclo, pchi, constantsDecadeInt32Factors[i], 0);
719 while (scale < minScale) {
720 if (!roundFlag) roundBit = 0;
721 i = minScale - scale;
722 if (i > DECIMAL_MAX_INTFACTORS) i = DECIMAL_MAX_INTFACTORS;
724 rc = mult128by32(pclo, pchi, constantsDecadeInt32Factors[i], roundBit);
725 if (rc != DECIMAL_SUCCESS) return rc;
729 TEST(scale >= 0 && scale <= DECIMAL_MAX_SCALE);
733 return normalize128(pclo, pchi, pScale, roundFlag, roundBit);
736 /* performs a += b */
737 gint32 mono_decimalIncr(/*[In, Out]*/decimal_repr* pA, /*[In]*/decimal_repr* pB)
739 guint64 alo, ahi, blo, bhi;
740 int log2A, log2B, log2Result, log10Result, rc;
741 int subFlag, sign, scaleA, scaleB;
743 DECTO128(pA, alo, ahi);
744 DECTO128(pB, blo, bhi);
746 sign = pA->signscale.sign;
747 subFlag = sign - (int)pB->signscale.sign;
748 scaleA = pA->signscale.scale;
749 scaleB = pB->signscale.scale;
750 if (scaleA == scaleB) {
751 /* same scale, that's easy */
753 sub128(alo, ahi, blo, bhi, &alo, &ahi);
754 if (ahi & LIT_GUINT64_HIGHBIT) {
762 add128(alo, ahi, blo, bhi, &alo, &ahi);
764 rc = normalize128(&alo, &ahi, &scaleA, 1, 0);
766 /* scales must be adjusted */
767 /* Estimate log10 and scale of result for adjusting scales */
768 log2A = log2withScale_128(alo, ahi, scaleA);
769 log2B = log2withScale_128(blo, bhi, scaleB);
770 log2Result = (log2A >= log2B) ? log2A : log2B;
771 if (!subFlag) log2Result++; /* result can have one bit more */
772 log10Result = (log2Result * 1000) / 3322 + 1;
773 /* we will calculate in 128bit, so we may need to adjust scale */
774 if (scaleB > scaleA) scaleA = scaleB;
775 if (scaleA + log10Result > DECIMAL_MAX_SCALE + 7) {
776 /* this may not fit in 128bit, so limit it */
777 scaleA = DECIMAL_MAX_SCALE + 7 - log10Result;
780 rc = adjustScale128(&alo, &ahi, scaleA - (int)pA->signscale.scale);
781 if (rc != DECIMAL_SUCCESS) return rc;
782 rc = adjustScale128(&blo, &bhi, scaleA - scaleB);
783 if (rc != DECIMAL_SUCCESS) return rc;
786 sub128(alo, ahi, blo, bhi, &alo, &ahi);
787 if (ahi & LIT_GUINT64_HIGHBIT) {
795 add128(alo, ahi, blo, bhi, &alo, &ahi);
798 if (rc != DECIMAL_SUCCESS) return rc;
800 rc = rescale128(&alo, &ahi,&scaleA, 0, 0, DECIMAL_MAX_SCALE, 1);
803 if (rc != DECIMAL_SUCCESS) return rc;
805 return pack128toDecimal(pA, alo, ahi, scaleA, sign);
808 /* performs a += factor * constants[idx] */
809 static int incMultConstant128(guint64* palo, guint64* pahi, int idx, int factor)
813 PRECONDITION(idx >= 0 && idx <= DECIMAL_MAX_SCALE);
814 PRECONDITION(factor > 0 && factor <= 9);
816 blo = dec128decadeFactors[idx].lo;
817 h = bhi = dec128decadeFactors[idx].hi;
819 mult128by32(&blo, &bhi, factor, 0);
820 if (h > bhi) return DECIMAL_OVERFLOW;
823 add128(*palo, *pahi, blo, bhi, palo, pahi);
824 if (h > *pahi) return DECIMAL_OVERFLOW;
825 return DECIMAL_SUCCESS;
828 DECINLINE static void div128DecadeFactor(guint64* palo, guint64* pahi, int powerOfTen)
830 int idx, roundBit = 0;
832 while (powerOfTen > 0) {
833 idx = (powerOfTen > DECIMAL_MAX_INTFACTORS) ? DECIMAL_MAX_INTFACTORS : powerOfTen;
835 roundBit = div128by32(palo, pahi, constantsDecadeInt32Factors[idx], 0);
838 if (roundBit) roundUp128(palo, pahi);
841 /* calc significant digits of mantisse */
842 DECINLINE static int calcDigits(guint64 alo, guint64 ahi)
849 return 0; /* zero has no signficant digits */
851 tlog2 = log2_64(alo);
854 tlog2 = 64 + log2_64(ahi);
857 tlog10 = (tlog2 * 1000) / 3322;
858 /* we need an exact floor value of log10(a) */
859 if (dec128decadeFactors[tlog10].hi > ahi
860 || (dec128decadeFactors[tlog10].hi == ahi
861 && dec128decadeFactors[tlog10].lo > alo)) {
867 gint32 mono_double2decimal(/*[Out]*/decimal_repr* pA, double val, gint32 digits)
870 guint64* p = (guint64*)(&val);
871 int sigDigits, sign, texp, rc, scale;
874 PRECONDITION(digits <= 15);
876 sign = ((*p & LIT_GUINT64_HIGHBIT) != 0) ? 1 : 0;
877 k = ((guint16)((*p) >> 52)) & 0x7FF;
878 alo = (*p & LIT_GUINT64(0xFFFFFFFFFFFFF)) | LIT_GUINT64(0x10000000000000);
881 texp = (k & 0x7FF) - 0x3FF;
882 if (k == 0x7FF || texp >= 96) return DECIMAL_OVERFLOW; /* NaNs, SNaNs, Infinities or >= 2^96 */
883 if (k == 0 || texp <= -94) { /* Subnormals, Zeros or < 2^-94 */
884 DECINIT(pA); /* return zero */
885 return DECIMAL_SUCCESS;
890 for (; texp > 0; texp--) {
891 lshift128(&alo, &ahi);
896 rc = rescale128(&alo, &ahi, &scale, -texp, 0, DECIMAL_MAX_SCALE, 0);
897 if (rc != DECIMAL_SUCCESS) return rc;
899 sigDigits = calcDigits(alo, ahi);
900 /* too much digits, then round */
901 if (sigDigits > digits) {
902 div128DecadeFactor(&alo, &ahi, sigDigits - digits);
903 scale -= sigDigits - digits;
904 /* check value, may be 10^(digits+1) caused by rounding */
905 if (ahi == dec128decadeFactors[digits].hi
906 && alo == dec128decadeFactors[digits].lo) {
907 div128by32(&alo, &ahi, 10, 0);
911 rc = mult128DecadeFactor(&alo, &ahi, -scale);
912 if (rc != DECIMAL_SUCCESS) return rc;
917 return pack128toDecimal(pA, alo, ahi, scale, sign);
921 * converts a digit string to decimal
922 * The significant digits must be passed as an integer in buf !
925 * if you want to convert the number 123.456789012345678901234 to decimal
926 * buf := "123456789012345678901234"
931 * you want to convert -79228162514264337593543950335 to decimal
932 * buf := "79228162514264337593543950335"
937 * you want to convert -7922816251426433759354395033.250000000000001 to decimal
938 * buf := "7922816251426433759354395033250000000000001"
941 * returns (decimal)-7922816251426433759354395033.3
944 * you want to convert -7922816251426433759354395033.250000000000000 to decimal
945 * buf := "7922816251426433759354395033250000000000000"
948 * returns (decimal)-7922816251426433759354395033.2
951 * you want to convert -7922816251426433759354395033.150000000000000 to decimal
952 * buf := "7922816251426433759354395033150000000000000"
955 * returns (decimal)-7922816251426433759354395033.2
957 * Uses banker's rule for rounding if there are more digits than can be
958 * represented by the significant
960 gint32 mono_string2decimal(/*[Out]*/decimal_repr* pA, MonoString* str, gint32 decrDecimal, gint32 sign)
962 gushort *buf = mono_string_chars(str);
965 int n, rc, i, len, sigLen = -1, firstNonZero;
966 int scale, roundBit = 0;
971 for (p = buf, len = 0; *p != 0; len++, p++) { }
973 for (p = buf, i = 0; *p != 0; i++, p++) {
975 if (n < 0 || n > 9) {
976 return DECIMAL_INVALID_CHARACTER;
981 sigLen = (len - firstNonZero > DECIMAL_MAX_SCALE+1)
982 ? DECIMAL_MAX_SCALE+1+firstNonZero : len;
983 if (decrDecimal > sigLen+1) return DECIMAL_OVERFLOW;
985 if (i >= sigLen) break;
986 rc = incMultConstant128(&alo, &ahi, sigLen - 1 - i, n);
987 if (rc != DECIMAL_SUCCESS) {
993 scale = sigLen - decrDecimal;
995 if (i < len) { /* too much digits, we must round */
997 if (n < 0 || n > 9) {
998 return DECIMAL_INVALID_CHARACTER;
1000 if (n > 5) roundBit = 1;
1001 else if (n == 5) { /* we must take a nearer look */
1003 for (++i; i < len; ++i) {
1004 if (buf[i] != '0') break; /* we are greater than .5 */
1006 if (i < len /* greater than exactly .5 */
1007 || n % 2 == 1) { /* exactly .5, use banker's rule for rounding */
1014 rc = normalize128(&alo, &ahi, &scale, 1, roundBit);
1015 if (rc != DECIMAL_SUCCESS) return rc;
1018 if (alo == 0 && ahi == 0) {
1020 return DECIMAL_SUCCESS;
1022 return pack128toDecimal(pA, alo, ahi, sigLen - decrDecimal, sign);
1027 * returns minimal number of digit string to represent decimal
1028 * No leading or trailing zeros !
1030 * *pA == 0 => buf = "", *pDecPos = 1, *pSign = 0
1031 * *pA == 12.34 => buf = "1234", *pDecPos = 2, *pSign = 0
1032 * *pA == -1000.0000 => buf = "1", *pDecPos = 4, *pSign = 1
1033 * *pA == -0.00000076 => buf = "76", *pDecPos = -6, *pSign = 0
1036 * pA decimal instance to convert
1037 * digits < 0: use decimals instead
1038 * = 0: gets mantisse as integer
1039 * > 0: gets at most <digits> digits, rounded according to banker's rule if necessary
1040 * decimals only used if digits < 0
1041 * >= 0: number of decimal places
1042 * buf pointer to result buffer
1043 * bufSize size of buffer
1044 * pDecPos receives insert position of decimal point relative to start of buffer
1045 * pSign receives sign
1048 gint32 mono_decimal2string(/*[In]*/decimal_repr* pA, gint32 digits, gint32 decimals,
1049 MonoArray* pArray, gint32 bufSize, gint32* pDecPos, gint32* pSign)
1052 guint16 *buf = (guint16*) mono_array_addr(pArray, guint16, 0);
1053 guint16 *q, *p = tmp;
1057 gint32 sigDigits, d;
1060 scale = pA->signscale.scale;
1061 DECTO128(pA, alo, ahi);
1062 sigDigits = calcDigits(alo, ahi); /* significant digits */
1064 /* calc needed digits (without leading or trailing zeros) */
1065 d = (digits == 0) ? sigDigits : digits;
1066 if (d < 0) { /* use decimals ? */
1067 if (0 <= decimals && decimals < scale) {
1068 d = sigDigits - scale + decimals;
1070 d = sigDigits; /* use all you can get */
1074 if (sigDigits > d) { /* we need to round decimal number */
1076 aa.signscale.scale = DECIMAL_MAX_SCALE;
1077 mono_decimalRound(&aa, DECIMAL_MAX_SCALE - sigDigits + d);
1078 DECTO128(&aa, alo, ahi);
1079 sigDigits += calcDigits(alo, ahi) - d;
1084 /* get digits starting from the tail */
1085 for (; (alo != 0 || ahi != 0) && len < 40; len++) {
1086 div128by32(&alo, &ahi, 10, &rest);
1087 *p++ = '0' + (char) rest;
1092 if (len >= bufSize) return DECIMAL_BUFFER_OVERFLOW;
1094 /* now we have the minimal count of digits,
1095 extend to wished count of digits or decimals */
1097 if (digits >= 0) { /* count digits */
1098 if (digits >= bufSize) return DECIMAL_BUFFER_OVERFLOW;
1100 /* zero or rounded to zero */
1103 /* copy significant digits */
1104 for (i = 0; i < len; i++) {
1107 *pDecPos = sigDigits - scale;
1109 /* add trailing zeros */
1110 for (i = len; i < digits; i++) {
1113 } else { /* count decimals */
1114 if (scale >= sigDigits) { /* add leading zeros */
1115 if (decimals+2 >= bufSize) return DECIMAL_BUFFER_OVERFLOW;
1117 for (i = 0; i <= scale - sigDigits; i++) {
1121 if (sigDigits - scale + decimals+1 >= bufSize) return DECIMAL_BUFFER_OVERFLOW;
1122 *pDecPos = sigDigits - scale;
1124 /* copy significant digits */
1125 for (i = 0; i < len; i++) {
1128 /* add trailing zeros */
1129 for (i = scale; i < decimals; i++) {
1135 *pSign = (sigDigits > 0) ? pA->signscale.sign : 0; /* zero has positive sign */
1137 return DECIMAL_SUCCESS;
1141 * converts a decimal to an UInt64 without rounding
1143 gint32 mono_decimal2UInt64(/*[In]*/decimal_repr* pA, guint64* pResult)
1148 DECTO128(pA, alo, ahi);
1149 scale = pA->signscale.scale;
1151 div128DecadeFactor(&alo, &ahi, scale);
1154 /* overflow if integer too large or < 0 */
1155 if (ahi != 0 || (alo != 0 && pA->signscale.sign)) return DECIMAL_OVERFLOW;
1158 return DECIMAL_SUCCESS;
1162 * converts a decimal to an Int64 without rounding
1164 gint32 mono_decimal2Int64(/*[In]*/decimal_repr* pA, gint64* pResult)
1169 DECTO128(pA, alo, ahi);
1170 scale = pA->signscale.scale;
1172 div128DecadeFactor(&alo, &ahi, scale);
1175 if (ahi != 0) return DECIMAL_OVERFLOW;
1177 sign = pA->signscale.sign;
1178 if (sign && alo != 0) {
1179 if (alo > LIT_GUINT64_HIGHBIT) return DECIMAL_OVERFLOW;
1180 *pResult = (gint64) ~(alo-1);
1182 if (alo & LIT_GUINT64_HIGHBIT) return DECIMAL_OVERFLOW;
1183 *pResult = (gint64) alo;
1186 return DECIMAL_SUCCESS;
1189 void mono_decimalFloorAndTrunc(/*[In, Out]*/decimal_repr* pA, gint32 floorFlag)
1192 guint32 factor, rest;
1193 int scale, sign, idx;
1196 scale = pA->signscale.scale;
1197 if (scale == 0) return; /* nothing to do */
1199 DECTO128(pA, alo, ahi);
1200 sign = pA->signscale.sign;
1203 idx = (scale > DECIMAL_MAX_INTFACTORS) ? DECIMAL_MAX_INTFACTORS : scale;
1204 factor = constantsDecadeInt32Factors[idx];
1206 div128by32(&alo, &ahi, factor, &rest);
1207 hasRest = hasRest || (rest != 0);
1210 if (floorFlag && hasRest && sign) { /* floor: if negative, we must round up */
1211 roundUp128(&alo, &ahi);
1214 pack128toDecimal(pA, alo, ahi, 0, sign);
1217 void mono_decimalRound(/*[In, Out]*/decimal_repr* pA, gint32 decimals)
1222 DECTO128(pA, alo, ahi);
1223 scale = pA->signscale.scale;
1224 sign = pA->signscale.sign;
1225 if (scale > decimals) {
1226 div128DecadeFactor(&alo, &ahi, scale - decimals);
1230 pack128toDecimal(pA, alo, ahi, scale, sign);
1233 gint32 mono_decimalMult(/*[In, Out]*/decimal_repr* pA, /*[In]*/decimal_repr* pB)
1235 guint64 low, mid, high;
1237 int scale, sign, rc;
1239 mult96by96to192(pA->lo32, pA->mid32, pA->hi32, pB->lo32, pB->mid32, pB->hi32,
1242 /* adjust scale and sign */
1243 scale = (int)pA->signscale.scale + (int)pB->signscale.scale;
1244 sign = pA->signscale.sign ^ pB->signscale.sign;
1246 /* first scaling step */
1247 factor = constantsDecadeInt32Factors[DECIMAL_MAX_INTFACTORS];
1248 while (high != 0 || (mid>>32) >= factor) {
1250 factor /= 1000; /* we need some digits for final rounding */
1251 scale -= DECIMAL_MAX_INTFACTORS - 3;
1253 scale -= DECIMAL_MAX_INTFACTORS;
1256 div192by32(&low, &mid, &high, factor);
1259 /* second and final scaling */
1260 rc = rescale128(&low, &mid, &scale, 0, 0, DECIMAL_MAX_SCALE, 1);
1261 if (rc != DECIMAL_SUCCESS) return rc;
1263 return pack128toDecimal(pA, low, mid, scale, sign);
1266 static int decimalDivSub(/*[In]*/decimal_repr* pA, /*[In]*/decimal_repr* pB,
1267 guint64* pclo, guint64* pchi, int* pExp)
1269 guint64 alo, ami, ahi;
1270 guint64 tlo, tmi, thi;
1271 guint32 blo, bmi, bhi;
1272 int ashift, bshift, extraBit, texp;
1274 ahi = (((guint64)(pA->hi32)) << 32) | pA->mid32;
1275 ami = ((guint64)(pA->lo32)) << 32;
1281 if (blo == 0 && bmi == 0 && bhi == 0) {
1282 return DECIMAL_DIVIDE_BY_ZERO;
1285 if (ami == 0 && ahi == 0) {
1287 return DECIMAL_FINISHED;
1290 /* enlarge dividend to get maximal precision */
1291 for (ashift = 0; (ahi & LIT_GUINT64_HIGHBIT) == 0; ++ashift) {
1292 lshift128(&ami, &ahi);
1295 /* ensure that divisor is at least 2^95 */
1296 for (bshift = 0; (bhi & LIT_GUINT32_HIGHBIT) == 0; ++bshift) {
1297 lshift96(&blo, &bmi, &bhi);
1300 thi = ((guint64)bhi)<<32 | bmi;
1301 tmi = ((guint64)blo)<<32;
1303 if (ahi > thi || (ahi == thi && ami >= tmi)) {
1304 sub192(alo, ami, ahi, tlo, tmi, thi, &alo, &ami, &ahi);
1310 div192by96to128(alo, ami, ahi, blo, bmi, bhi, pclo, pchi);
1311 texp = 128 + ashift - bshift;
1314 rshift128(pclo, pchi);
1315 *pchi += LIT_GUINT64_HIGHBIT;
1319 /* try loss free right shift */
1320 while (texp > 0 && (*pclo & 1) == 0) {
1322 rshift128(pclo, pchi);
1328 return DECIMAL_SUCCESS;
1331 gint32 mono_decimalDiv(/*[Out]*/decimal_repr* pC, /*[In]*/decimal_repr* pA, /*[In]*/decimal_repr* pB)
1333 guint64 clo, chi; /* result */
1334 int scale, texp, rc;
1336 rc = decimalDivSub(pA, pB, &clo, &chi, &texp);
1337 if (rc != DECIMAL_SUCCESS) {
1338 if (rc == DECIMAL_FINISHED) rc = DECIMAL_SUCCESS;
1342 /* adjust scale and sign */
1343 scale = (int)pA->signscale.scale - (int)pB->signscale.scale;
1345 /*test: printf("0: %.17e\n", (((double)chi) * pow(2,64) + clo) * pow(10, -scale) * pow(2, -exp));*/
1346 rc = rescale128(&clo, &chi, &scale, texp, 0, DECIMAL_MAX_SCALE, 1);
1347 if (rc != DECIMAL_SUCCESS) return rc;
1349 return pack128toDecimal(pC, clo, chi, scale, pA->signscale.sign ^ pB->signscale.sign);
1352 gint32 mono_decimalIntDiv(/*[Out]*/decimal_repr* pC, /*[In]*/decimal_repr* pA, /*[In]*/decimal_repr* pB)
1354 guint64 clo, chi; /* result */
1355 int scale, texp, rc;
1357 rc = decimalDivSub(pA, pB, &clo, &chi, &texp);
1358 if (rc != DECIMAL_SUCCESS) {
1359 if (rc == DECIMAL_FINISHED) rc = DECIMAL_SUCCESS;
1364 scale = (int)pA->signscale.scale - (int)pB->signscale.scale;
1366 /* truncate result to integer */
1367 rc = rescale128(&clo, &chi, &scale, texp, 0, 0, 0);
1368 if (rc != DECIMAL_SUCCESS) return rc;
1370 return pack128toDecimal(pC, clo, chi, scale, pA->signscale.sign);
1373 /* approximation for log2 of a
1374 If q is the exact value for log2(a), then q <= decimalLog2(a) <= q+1 */
1375 DECINLINE static int decimalLog2(/*[In]*/decimal_repr* pA)
1378 int scale = pA->signscale.scale;
1380 if (pA->hi32 != 0) tlog2 = 64 + log2_32(pA->hi32);
1381 else if (pA->mid32 != 0) tlog2 = 32 + log2_32(pA->mid32);
1382 else tlog2 = log2_32(pA->lo32);
1384 if (tlog2 != DECIMAL_LOG_NEGINF) {
1385 tlog2 -= (scale * 33219) / 10000;
1391 DECINLINE static int decimalIsZero(/*[In]*/decimal_repr* pA)
1393 return (pA->lo32 == 0 && pA->mid32 == 0 && pA->hi32 == 0);
1396 gint32 mono_decimalCompare(/*[In]*/decimal_repr* pA, /*[In]*/decimal_repr* pB)
1398 int log2a, log2b, delta, sign;
1401 sign = (pA->signscale.sign) ? -1 : 1;
1403 if (pA->signscale.sign ^ pB->signscale.sign) {
1404 return (decimalIsZero(pA) && decimalIsZero(pB)) ? 0 : sign;
1407 /* try fast comparison via log2 */
1408 log2a = decimalLog2(pA);
1409 log2b = decimalLog2(pB);
1410 delta = log2a - log2b;
1411 /* decimalLog2 is not exact, so we can say nothing
1412 if abs(delta) <= 1 */
1413 if (delta < -1) return -sign;
1414 if (delta > 1) return sign;
1418 mono_decimalIncr(&aa, pB);
1420 if (decimalIsZero(&aa)) return 0;
1422 return (aa.signscale.sign) ? 1 : -1;
1425 /* d=(-1)^sign * n * 2^(k-52) with sign (1bit), k(11bit), n-2^52(52bit) */
1426 DECINLINE static void buildIEEE754Double(double* pd, int sign, int texp, guint64 mantisse)
1428 guint64* p = (guint64*) pd;
1430 PRECONDITION(sign == 0 || sign == 1);
1431 *p = (((guint64)sign) << 63) | (((guint64)((1023+texp)&0x7ff)) << 52) | mantisse;
1434 double mono_decimal2double(/*[In]*/decimal_repr* pA)
1437 guint64 alo, ahi, mantisse;
1438 guint32 overhang, factor, roundBits;
1439 int scale, texp, log5, i;
1441 ahi = (((guint64)(pA->hi32)) << 32) | pA->mid32;
1442 alo = ((guint64)(pA->lo32)) << 32;
1444 /* special case zero */
1445 if (ahi == 0 && alo == 0) return 0.0;
1448 scale = pA->signscale.scale;
1450 /* transform n * 10^-scale and exp = 0 => m * 2^-exp and scale = 0 */
1452 while ((ahi & LIT_GUINT64_HIGHBIT) == 0) {
1453 lshift128(&alo, &ahi);
1457 overhang = (guint32) (ahi >> 32);
1458 if (overhang >= 5) {
1460 log5 = (log2_32(overhang) * 1000) / 2322; /* ln(5)/ln(2) = 2.3219... */
1461 if (log5 < DECIMAL_MAX_INTFACTORS) {
1462 /* get maximal factor=5^i, so that overhang / factor >= 1 */
1463 factor = constantsDecadeInt32Factors[log5] >> log5; /* 5^n = 10^n/2^n */
1464 i = log5 + overhang / factor;
1466 i = DECIMAL_MAX_INTFACTORS; /* we have only constants up to 10^DECIMAL_MAX_INTFACTORS */
1468 if (i > scale) i = scale;
1469 factor = constantsDecadeInt32Factors[i] >> i; /* 5^n = 10^n/2^n */
1470 /* n * 10^-scale * 2^-exp => m * 10^-(scale-i) * 2^-(exp+i) with m = n * 5^-i */
1471 div128by32(&alo, &ahi, factor, 0);
1477 /* normalize significand (highest bit should be 1) */
1478 while ((ahi & LIT_GUINT64_HIGHBIT) == 0) {
1479 lshift128(&alo, &ahi);
1483 /* round to nearest even */
1484 roundBits = (guint32)ahi & 0x7ff;
1486 if ((ahi & LIT_GUINT64_HIGHBIT) == 0) { /* overflow ? */
1489 } else if ((roundBits & 0x400) == 0) ahi &= ~1;
1491 /* 96 bit => 1 implizit bit and 52 explicit bits */
1492 mantisse = (ahi & ~LIT_GUINT64_HIGHBIT) >> 11;
1494 buildIEEE754Double(&d, pA->signscale.sign, -texp+95, mantisse);
1500 gint32 mono_decimalSetExponent(/*[In, Out]*/decimal_repr* pA, gint32 texp)
1504 int scale = pA->signscale.scale;
1508 if (scale < 0 || scale > DECIMAL_MAX_SCALE) {
1509 DECTO128(pA, alo, ahi);
1510 rc = rescale128(&alo, &ahi, &scale, 0, 0, DECIMAL_MAX_SCALE, 1);
1511 if (rc != DECIMAL_SUCCESS) return rc;
1512 return pack128toDecimal(pA, alo, ahi, scale, pA->signscale.sign);
1514 pA->signscale.scale = scale;
1515 return DECIMAL_SUCCESS;