| /* ------------------------------------------------------------------ */ | |
| /* decCommon.c -- common code for all three fixed-size types */ | |
| /* ------------------------------------------------------------------ */ | |
| /* Copyright (c) IBM Corporation, 2000, 2010. All rights reserved. */ | |
| /* */ | |
| /* This software is made available under the terms of the */ | |
| /* ICU License -- ICU 1.8.1 and later. */ | |
| /* */ | |
| /* The description and User's Guide ("The decNumber C Library") for */ | |
| /* this software is included in the package as decNumber.pdf. This */ | |
| /* document is also available in HTML, together with specifications, */ | |
| /* testcases, and Web links, on the General Decimal Arithmetic page. */ | |
| /* */ | |
| /* Please send comments, suggestions, and corrections to the author: */ | |
| /* mfc@uk.ibm.com */ | |
| /* Mike Cowlishaw, IBM Fellow */ | |
| /* IBM UK, PO Box 31, Birmingham Road, Warwick CV34 5JL, UK */ | |
| /* ------------------------------------------------------------------ */ | |
| /* This module comprises code that is shared between all the formats */ | |
| /* (decSingle, decDouble, and decQuad); it includes set and extract */ | |
| /* of format components, widening, narrowing, and string conversions. */ | |
| /* */ | |
| /* Unlike decNumber, parameterization takes place at compile time */ | |
| /* rather than at runtime. The parameters are set in the decDouble.c */ | |
| /* (etc.) files, which then include this one to produce the compiled */ | |
| /* code. The functions here, therefore, are code shared between */ | |
| /* multiple formats. */ | |
| /* ------------------------------------------------------------------ */ | |
| // Names here refer to decFloat rather than to decDouble, etc., and | |
| // the functions are in strict alphabetical order. | |
| // Constants, tables, and debug function(s) are included only for QUAD | |
| // (which will always be compiled if DOUBLE or SINGLE are used). | |
| // | |
| // Whenever a decContext is used, only the status may be set (using | |
| // OR) or the rounding mode read; all other fields are ignored and | |
| // untouched. | |
| // names for simpler testing and default context | |
| #if DECPMAX==7 | |
| #define SINGLE 1 | |
| #define DOUBLE 0 | |
| #define QUAD 0 | |
| #define DEFCONTEXT DEC_INIT_DECIMAL32 | |
| #elif DECPMAX==16 | |
| #define SINGLE 0 | |
| #define DOUBLE 1 | |
| #define QUAD 0 | |
| #define DEFCONTEXT DEC_INIT_DECIMAL64 | |
| #elif DECPMAX==34 | |
| #define SINGLE 0 | |
| #define DOUBLE 0 | |
| #define QUAD 1 | |
| #define DEFCONTEXT DEC_INIT_DECIMAL128 | |
| #else | |
| #error Unexpected DECPMAX value | |
| #endif | |
| /* Assertions */ | |
| #if DECPMAX!=7 && DECPMAX!=16 && DECPMAX!=34 | |
| #error Unexpected Pmax (DECPMAX) value for this module | |
| #endif | |
| // Assert facts about digit characters, etc. | |
| #if ('9'&0x0f)!=9 | |
| #error This module assumes characters are of the form 0b....nnnn | |
| // where .... are don't care 4 bits and nnnn is 0000 through 1001 | |
| #endif | |
| #if ('9'&0xf0)==('.'&0xf0) | |
| #error This module assumes '.' has a different mask than a digit | |
| #endif | |
| // Assert ToString lay-out conditions | |
| #if DECSTRING<DECPMAX+9 | |
| #error ToString needs at least 8 characters for lead-in and dot | |
| #endif | |
| #if DECPMAX+DECEMAXD+5 > DECSTRING | |
| #error Exponent form can be too long for ToString to lay out safely | |
| #endif | |
| #if DECEMAXD > 4 | |
| #error Exponent form is too long for ToString to lay out | |
| // Note: code for up to 9 digits exists in archives [decOct] | |
| #endif | |
| /* Private functions used here and possibly in decBasic.c, etc. */ | |
| static decFloat * decFinalize(decFloat *, bcdnum *, decContext *); | |
| static Flag decBiStr(const char *, const char *, const char *); | |
| /* Macros and private tables; those which are not format-dependent */ | |
| /* are only included if decQuad is being built. */ | |
| /* ------------------------------------------------------------------ */ | |
| /* Combination field lookup tables (uInts to save measurable work) */ | |
| /* */ | |
| /* DECCOMBEXP - 2 most-significant-bits of exponent (00, 01, or */ | |
| /* 10), shifted left for format, or DECFLOAT_Inf/NaN */ | |
| /* DECCOMBWEXP - The same, for the next-wider format (unless QUAD) */ | |
| /* DECCOMBMSD - 4-bit most-significant-digit */ | |
| /* [0 if the index is a special (Infinity or NaN)] */ | |
| /* DECCOMBFROM - 5-bit combination field from EXP top bits and MSD */ | |
| /* (placed in uInt so no shift is needed) */ | |
| /* */ | |
| /* DECCOMBEXP, DECCOMBWEXP, and DECCOMBMSD are indexed by the sign */ | |
| /* and 5-bit combination field (0-63, the second half of the table */ | |
| /* identical to the first half) */ | |
| /* DECCOMBFROM is indexed by expTopTwoBits*16 + msd */ | |
| /* */ | |
| /* DECCOMBMSD and DECCOMBFROM are not format-dependent and so are */ | |
| /* only included once, when QUAD is being built */ | |
| /* ------------------------------------------------------------------ */ | |
| static const uInt DECCOMBEXP[64]={ | |
| 0, 0, 0, 0, 0, 0, 0, 0, | |
| 1<<DECECONL, 1<<DECECONL, 1<<DECECONL, 1<<DECECONL, | |
| 1<<DECECONL, 1<<DECECONL, 1<<DECECONL, 1<<DECECONL, | |
| 2<<DECECONL, 2<<DECECONL, 2<<DECECONL, 2<<DECECONL, | |
| 2<<DECECONL, 2<<DECECONL, 2<<DECECONL, 2<<DECECONL, | |
| 0, 0, 1<<DECECONL, 1<<DECECONL, | |
| 2<<DECECONL, 2<<DECECONL, DECFLOAT_Inf, DECFLOAT_NaN, | |
| 0, 0, 0, 0, 0, 0, 0, 0, | |
| 1<<DECECONL, 1<<DECECONL, 1<<DECECONL, 1<<DECECONL, | |
| 1<<DECECONL, 1<<DECECONL, 1<<DECECONL, 1<<DECECONL, | |
| 2<<DECECONL, 2<<DECECONL, 2<<DECECONL, 2<<DECECONL, | |
| 2<<DECECONL, 2<<DECECONL, 2<<DECECONL, 2<<DECECONL, | |
| 0, 0, 1<<DECECONL, 1<<DECECONL, | |
| 2<<DECECONL, 2<<DECECONL, DECFLOAT_Inf, DECFLOAT_NaN}; | |
| #if !QUAD | |
| static const uInt DECCOMBWEXP[64]={ | |
| 0, 0, 0, 0, 0, 0, 0, 0, | |
| 1<<DECWECONL, 1<<DECWECONL, 1<<DECWECONL, 1<<DECWECONL, | |
| 1<<DECWECONL, 1<<DECWECONL, 1<<DECWECONL, 1<<DECWECONL, | |
| 2<<DECWECONL, 2<<DECWECONL, 2<<DECWECONL, 2<<DECWECONL, | |
| 2<<DECWECONL, 2<<DECWECONL, 2<<DECWECONL, 2<<DECWECONL, | |
| 0, 0, 1<<DECWECONL, 1<<DECWECONL, | |
| 2<<DECWECONL, 2<<DECWECONL, DECFLOAT_Inf, DECFLOAT_NaN, | |
| 0, 0, 0, 0, 0, 0, 0, 0, | |
| 1<<DECWECONL, 1<<DECWECONL, 1<<DECWECONL, 1<<DECWECONL, | |
| 1<<DECWECONL, 1<<DECWECONL, 1<<DECWECONL, 1<<DECWECONL, | |
| 2<<DECWECONL, 2<<DECWECONL, 2<<DECWECONL, 2<<DECWECONL, | |
| 2<<DECWECONL, 2<<DECWECONL, 2<<DECWECONL, 2<<DECWECONL, | |
| 0, 0, 1<<DECWECONL, 1<<DECWECONL, | |
| 2<<DECWECONL, 2<<DECWECONL, DECFLOAT_Inf, DECFLOAT_NaN}; | |
| #endif | |
| #if QUAD | |
| const uInt DECCOMBMSD[64]={ | |
| 0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4, 5, 6, 7, | |
| 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 8, 9, 8, 9, 0, 0, | |
| 0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4, 5, 6, 7, | |
| 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 8, 9, 8, 9, 0, 0}; | |
| const uInt DECCOMBFROM[48]={ | |
| 0x00000000, 0x04000000, 0x08000000, 0x0C000000, 0x10000000, 0x14000000, | |
| 0x18000000, 0x1C000000, 0x60000000, 0x64000000, 0x00000000, 0x00000000, | |
| 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x20000000, 0x24000000, | |
| 0x28000000, 0x2C000000, 0x30000000, 0x34000000, 0x38000000, 0x3C000000, | |
| 0x68000000, 0x6C000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, | |
| 0x00000000, 0x00000000, 0x40000000, 0x44000000, 0x48000000, 0x4C000000, | |
| 0x50000000, 0x54000000, 0x58000000, 0x5C000000, 0x70000000, 0x74000000, | |
| 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000}; | |
| /* ------------------------------------------------------------------ */ | |
| /* Request and include the tables to use for conversions */ | |
| /* ------------------------------------------------------------------ */ | |
| #define DEC_BCD2DPD 1 // 0-0x999 -> DPD | |
| #define DEC_BIN2DPD 1 // 0-999 -> DPD | |
| #define DEC_BIN2BCD8 1 // 0-999 -> ddd, len | |
| #define DEC_DPD2BCD8 1 // DPD -> ddd, len | |
| #define DEC_DPD2BIN 1 // DPD -> 0-999 | |
| #define DEC_DPD2BINK 1 // DPD -> 0-999000 | |
| #define DEC_DPD2BINM 1 // DPD -> 0-999000000 | |
| #include "decDPD.h" // source of the lookup tables | |
| #endif | |
| /* ----------------------------------------------------------------- */ | |
| /* decBiStr -- compare string with pairwise options */ | |
| /* */ | |
| /* targ is the string to compare */ | |
| /* str1 is one of the strings to compare against (length may be 0) */ | |
| /* str2 is the other; it must be the same length as str1 */ | |
| /* */ | |
| /* returns 1 if strings compare equal, (that is, targ is the same */ | |
| /* length as str1 and str2, and each character of targ is in one */ | |
| /* of str1 or str2 in the corresponding position), or 0 otherwise */ | |
| /* */ | |
| /* This is used for generic caseless compare, including the awkward */ | |
| /* case of the Turkish dotted and dotless Is. Use as (for example): */ | |
| /* if (decBiStr(test, "mike", "MIKE")) ... */ | |
| /* ----------------------------------------------------------------- */ | |
| static Flag decBiStr(const char *targ, const char *str1, const char *str2) { | |
| for (;;targ++, str1++, str2++) { | |
| if (*targ!=*str1 && *targ!=*str2) return 0; | |
| // *targ has a match in one (or both, if terminator) | |
| if (*targ=='\0') break; | |
| } // forever | |
| return 1; | |
| } // decBiStr | |
| /* ------------------------------------------------------------------ */ | |
| /* decFinalize -- adjust and store a final result */ | |
| /* */ | |
| /* df is the decFloat format number which gets the final result */ | |
| /* num is the descriptor of the number to be checked and encoded */ | |
| /* [its values, including the coefficient, may be modified] */ | |
| /* set is the context to use */ | |
| /* returns df */ | |
| /* */ | |
| /* The num descriptor may point to a bcd8 string of any length; this */ | |
| /* string may have leading insignificant zeros. If it has more than */ | |
| /* DECPMAX digits then the final digit can be a round-for-reround */ | |
| /* digit (i.e., it may include a sticky bit residue). */ | |
| /* */ | |
| /* The exponent (q) may be one of the codes for a special value and */ | |
| /* can be up to 999999999 for conversion from string. */ | |
| /* */ | |
| /* No error is possible, but Inexact, Underflow, and/or Overflow may */ | |
| /* be set. */ | |
| /* ------------------------------------------------------------------ */ | |
| // Constant whose size varies with format; also the check for surprises | |
| static uByte allnines[DECPMAX]= | |
| #if SINGLE | |
| {9, 9, 9, 9, 9, 9, 9}; | |
| #elif DOUBLE | |
| {9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9}; | |
| #elif QUAD | |
| {9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, | |
| 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9}; | |
| #endif | |
| static decFloat * decFinalize(decFloat *df, bcdnum *num, | |
| decContext *set) { | |
| uByte *ub; // work | |
| uInt dpd; // .. | |
| uInt uiwork; // for macros | |
| uByte *umsd=num->msd; // local copy | |
| uByte *ulsd=num->lsd; // .. | |
| uInt encode; // encoding accumulator | |
| Int length; // coefficient length | |
| #if DECCHECK | |
| Int clen=ulsd-umsd+1; | |
| #if QUAD | |
| #define COEXTRA 2 // extra-long coefficent | |
| #else | |
| #define COEXTRA 0 | |
| #endif | |
| if (clen<1 || clen>DECPMAX*3+2+COEXTRA) | |
| printf("decFinalize: suspect coefficient [length=%ld]\n", (LI)clen); | |
| if (num->sign!=0 && num->sign!=DECFLOAT_Sign) | |
| printf("decFinalize: bad sign [%08lx]\n", (LI)num->sign); | |
| if (!EXPISSPECIAL(num->exponent) | |
| && (num->exponent>1999999999 || num->exponent<-1999999999)) | |
| printf("decFinalize: improbable exponent [%ld]\n", (LI)num->exponent); | |
| // decShowNum(num, "final"); | |
| #endif | |
| // A special will have an 'exponent' which is very positive and a | |
| // coefficient < DECPMAX | |
| length=(uInt)(ulsd-umsd+1); // coefficient length | |
| if (!NUMISSPECIAL(num)) { | |
| Int drop; // digits to be dropped | |
| // skip leading insignificant zeros to calculate an exact length | |
| // [this is quite expensive] | |
| if (*umsd==0) { | |
| for (; umsd+3<ulsd && UBTOUI(umsd)==0;) umsd+=4; | |
| for (; *umsd==0 && umsd<ulsd;) umsd++; | |
| length=ulsd-umsd+1; // recalculate | |
| } | |
| drop=MAXI(length-DECPMAX, DECQTINY-num->exponent); | |
| // drop can now be > digits for bottom-clamp (subnormal) cases | |
| if (drop>0) { // rounding needed | |
| // (decFloatQuantize has very similar code to this, so any | |
| // changes may need to be made there, too) | |
| uByte *roundat; // -> re-round digit | |
| uByte reround; // reround value | |
| // printf("Rounding; drop=%ld\n", (LI)drop); | |
| num->exponent+=drop; // always update exponent | |
| // Three cases here: | |
| // 1. new LSD is in coefficient (almost always) | |
| // 2. new LSD is digit to left of coefficient (so MSD is | |
| // round-for-reround digit) | |
| // 3. new LSD is to left of case 2 (whole coefficient is sticky) | |
| // [duplicate check-stickies code to save a test] | |
| // [by-digit check for stickies as runs of zeros are rare] | |
| if (drop<length) { // NB lengths not addresses | |
| roundat=umsd+length-drop; | |
| reround=*roundat; | |
| for (ub=roundat+1; ub<=ulsd; ub++) { | |
| if (*ub!=0) { // non-zero to be discarded | |
| reround=DECSTICKYTAB[reround]; // apply sticky bit | |
| break; // [remainder don't-care] | |
| } | |
| } // check stickies | |
| ulsd=roundat-1; // new LSD | |
| } | |
| else { // edge case | |
| if (drop==length) { | |
| roundat=umsd; | |
| reround=*roundat; | |
| } | |
| else { | |
| roundat=umsd-1; | |
| reround=0; | |
| } | |
| for (ub=roundat+1; ub<=ulsd; ub++) { | |
| if (*ub!=0) { // non-zero to be discarded | |
| reround=DECSTICKYTAB[reround]; // apply sticky bit | |
| break; // [remainder don't-care] | |
| } | |
| } // check stickies | |
| *umsd=0; // coefficient is a 0 | |
| ulsd=umsd; // .. | |
| } | |
| if (reround!=0) { // discarding non-zero | |
| uInt bump=0; | |
| set->status|=DEC_Inexact; | |
| // if adjusted exponent [exp+digits-1] is < EMIN then num is | |
| // subnormal -- so raise Underflow | |
| if (num->exponent<DECEMIN && (num->exponent+(ulsd-umsd+1)-1)<DECEMIN) | |
| set->status|=DEC_Underflow; | |
| // next decide whether increment of the coefficient is needed | |
| if (set->round==DEC_ROUND_HALF_EVEN) { // fastpath slowest case | |
| if (reround>5) bump=1; // >0.5 goes up | |
| else if (reround==5) // exactly 0.5000 .. | |
| bump=*ulsd & 0x01; // .. up iff [new] lsd is odd | |
| } // r-h-e | |
| else switch (set->round) { | |
| case DEC_ROUND_DOWN: { | |
| // no change | |
| break;} // r-d | |
| case DEC_ROUND_HALF_DOWN: { | |
| if (reround>5) bump=1; | |
| break;} // r-h-d | |
| case DEC_ROUND_HALF_UP: { | |
| if (reround>=5) bump=1; | |
| break;} // r-h-u | |
| case DEC_ROUND_UP: { | |
| if (reround>0) bump=1; | |
| break;} // r-u | |
| case DEC_ROUND_CEILING: { | |
| // same as _UP for positive numbers, and as _DOWN for negatives | |
| if (!num->sign && reround>0) bump=1; | |
| break;} // r-c | |
| case DEC_ROUND_FLOOR: { | |
| // same as _UP for negative numbers, and as _DOWN for positive | |
| // [negative reround cannot occur on 0] | |
| if (num->sign && reround>0) bump=1; | |
| break;} // r-f | |
| case DEC_ROUND_05UP: { | |
| if (reround>0) { // anything out there is 'sticky' | |
| // bump iff lsd=0 or 5; this cannot carry so it could be | |
| // effected immediately with no bump -- but the code | |
| // is clearer if this is done the same way as the others | |
| if (*ulsd==0 || *ulsd==5) bump=1; | |
| } | |
| break;} // r-r | |
| default: { // e.g., DEC_ROUND_MAX | |
| set->status|=DEC_Invalid_context; | |
| #if DECCHECK | |
| printf("Unknown rounding mode: %ld\n", (LI)set->round); | |
| #endif | |
| break;} | |
| } // switch (not r-h-e) | |
| // printf("ReRound: %ld bump: %ld\n", (LI)reround, (LI)bump); | |
| if (bump!=0) { // need increment | |
| // increment the coefficient; this might end up with 1000... | |
| // (after the all nines case) | |
| ub=ulsd; | |
| for(; ub-3>=umsd && UBTOUI(ub-3)==0x09090909; ub-=4) { | |
| UBFROMUI(ub-3, 0); // to 00000000 | |
| } | |
| // [note ub could now be to left of msd, and it is not safe | |
| // to write to the the left of the msd] | |
| // now at most 3 digits left to non-9 (usually just the one) | |
| for (; ub>=umsd; *ub=0, ub--) { | |
| if (*ub==9) continue; // carry | |
| *ub+=1; | |
| break; | |
| } | |
| if (ub<umsd) { // had all-nines | |
| *umsd=1; // coefficient to 1000... | |
| // usually the 1000... coefficient can be used as-is | |
| if ((ulsd-umsd+1)==DECPMAX) { | |
| num->exponent++; | |
| } | |
| else { | |
| // if coefficient is shorter than Pmax then num is | |
| // subnormal, so extend it; this is safe as drop>0 | |
| // (or, if the coefficient was supplied above, it could | |
| // not be 9); this may make the result normal. | |
| ulsd++; | |
| *ulsd=0; | |
| // [exponent unchanged] | |
| #if DECCHECK | |
| if (num->exponent!=DECQTINY) // sanity check | |
| printf("decFinalize: bad all-nines extend [^%ld, %ld]\n", | |
| (LI)num->exponent, (LI)(ulsd-umsd+1)); | |
| #endif | |
| } // subnormal extend | |
| } // had all-nines | |
| } // bump needed | |
| } // inexact rounding | |
| length=ulsd-umsd+1; // recalculate (may be <DECPMAX) | |
| } // need round (drop>0) | |
| // The coefficient will now fit and has final length unless overflow | |
| // decShowNum(num, "rounded"); | |
| // if exponent is >=emax may have to clamp, overflow, or fold-down | |
| if (num->exponent>DECEMAX-(DECPMAX-1)) { // is edge case | |
| // printf("overflow checks...\n"); | |
| if (*ulsd==0 && ulsd==umsd) { // have zero | |
| num->exponent=DECEMAX-(DECPMAX-1); // clamp to max | |
| } | |
| else if ((num->exponent+length-1)>DECEMAX) { // > Nmax | |
| // Overflow -- these could go straight to encoding, here, but | |
| // instead num is adjusted to keep the code cleaner | |
| Flag needmax=0; // 1 for finite result | |
| set->status|=(DEC_Overflow | DEC_Inexact); | |
| switch (set->round) { | |
| case DEC_ROUND_DOWN: { | |
| needmax=1; // never Infinity | |
| break;} // r-d | |
| case DEC_ROUND_05UP: { | |
| needmax=1; // never Infinity | |
| break;} // r-05 | |
| case DEC_ROUND_CEILING: { | |
| if (num->sign) needmax=1; // Infinity iff non-negative | |
| break;} // r-c | |
| case DEC_ROUND_FLOOR: { | |
| if (!num->sign) needmax=1; // Infinity iff negative | |
| break;} // r-f | |
| default: break; // Infinity in all other cases | |
| } | |
| if (!needmax) { // easy .. set Infinity | |
| num->exponent=DECFLOAT_Inf; | |
| *umsd=0; // be clean: coefficient to 0 | |
| ulsd=umsd; // .. | |
| } | |
| else { // return Nmax | |
| umsd=allnines; // use constant array | |
| ulsd=allnines+DECPMAX-1; | |
| num->exponent=DECEMAX-(DECPMAX-1); | |
| } | |
| } | |
| else { // no overflow but non-zero and may have to fold-down | |
| Int shift=num->exponent-(DECEMAX-(DECPMAX-1)); | |
| if (shift>0) { // fold-down needed | |
| // fold down needed; must copy to buffer in order to pad | |
| // with zeros safely; fortunately this is not the worst case | |
| // path because cannot have had a round | |
| uByte buffer[ROUNDUP(DECPMAX+3, 4)]; // [+3 allows uInt padding] | |
| uByte *s=umsd; // source | |
| uByte *t=buffer; // safe target | |
| uByte *tlsd=buffer+(ulsd-umsd)+shift; // target LSD | |
| // printf("folddown shift=%ld\n", (LI)shift); | |
| for (; s<=ulsd; s+=4, t+=4) UBFROMUI(t, UBTOUI(s)); | |
| for (t=tlsd-shift+1; t<=tlsd; t+=4) UBFROMUI(t, 0); // pad 0s | |
| num->exponent-=shift; | |
| umsd=buffer; | |
| ulsd=tlsd; | |
| } | |
| } // fold-down? | |
| length=ulsd-umsd+1; // recalculate length | |
| } // high-end edge case | |
| } // finite number | |
| /*------------------------------------------------------------------*/ | |
| /* At this point the result will properly fit the decFloat */ | |
| /* encoding, and it can be encoded with no possibility of error */ | |
| /*------------------------------------------------------------------*/ | |
| // Following code does not alter coefficient (could be allnines array) | |
| // fast path possible when DECPMAX digits | |
| if (length==DECPMAX) { | |
| return decFloatFromBCD(df, num->exponent, umsd, num->sign); | |
| } // full-length | |
| // slower path when not a full-length number; must care about length | |
| // [coefficient length here will be < DECPMAX] | |
| if (!NUMISSPECIAL(num)) { // is still finite | |
| // encode the combination field and exponent continuation | |
| uInt uexp=(uInt)(num->exponent+DECBIAS); // biased exponent | |
| uInt code=(uexp>>DECECONL)<<4; // top two bits of exp | |
| // [msd==0] | |
| // look up the combination field and make high word | |
| encode=DECCOMBFROM[code]; // indexed by (0-2)*16+msd | |
| encode|=(uexp<<(32-6-DECECONL)) & 0x03ffffff; // exponent continuation | |
| } | |
| else encode=num->exponent; // special [already in word] | |
| encode|=num->sign; // add sign | |
| // private macro to extract a declet, n (where 0<=n<DECLETS and 0 | |
| // refers to the declet from the least significant three digits) | |
| // and put the corresponding DPD code into dpd. Access to umsd and | |
| // ulsd (pointers to the most and least significant digit of the | |
| // variable-length coefficient) is assumed, along with use of a | |
| // working pointer, uInt *ub. | |
| // As not full-length then chances are there are many leading zeros | |
| // [and there may be a partial triad] | |
| #define getDPDt(dpd, n) ub=ulsd-(3*(n))-2; \ | |
| if (ub<umsd-2) dpd=0; \ | |
| else if (ub>=umsd) dpd=BCD2DPD[(*ub*256)+(*(ub+1)*16)+*(ub+2)]; \ | |
| else {dpd=*(ub+2); if (ub+1==umsd) dpd+=*(ub+1)*16; dpd=BCD2DPD[dpd];} | |
| // place the declets in the encoding words and copy to result (df), | |
| // according to endianness; in all cases complete the sign word | |
| // first | |
| #if DECPMAX==7 | |
| getDPDt(dpd, 1); | |
| encode|=dpd<<10; | |
| getDPDt(dpd, 0); | |
| encode|=dpd; | |
| DFWORD(df, 0)=encode; // just the one word | |
| #elif DECPMAX==16 | |
| getDPDt(dpd, 4); encode|=dpd<<8; | |
| getDPDt(dpd, 3); encode|=dpd>>2; | |
| DFWORD(df, 0)=encode; | |
| encode=dpd<<30; | |
| getDPDt(dpd, 2); encode|=dpd<<20; | |
| getDPDt(dpd, 1); encode|=dpd<<10; | |
| getDPDt(dpd, 0); encode|=dpd; | |
| DFWORD(df, 1)=encode; | |
| #elif DECPMAX==34 | |
| getDPDt(dpd,10); encode|=dpd<<4; | |
| getDPDt(dpd, 9); encode|=dpd>>6; | |
| DFWORD(df, 0)=encode; | |
| encode=dpd<<26; | |
| getDPDt(dpd, 8); encode|=dpd<<16; | |
| getDPDt(dpd, 7); encode|=dpd<<6; | |
| getDPDt(dpd, 6); encode|=dpd>>4; | |
| DFWORD(df, 1)=encode; | |
| encode=dpd<<28; | |
| getDPDt(dpd, 5); encode|=dpd<<18; | |
| getDPDt(dpd, 4); encode|=dpd<<8; | |
| getDPDt(dpd, 3); encode|=dpd>>2; | |
| DFWORD(df, 2)=encode; | |
| encode=dpd<<30; | |
| getDPDt(dpd, 2); encode|=dpd<<20; | |
| getDPDt(dpd, 1); encode|=dpd<<10; | |
| getDPDt(dpd, 0); encode|=dpd; | |
| DFWORD(df, 3)=encode; | |
| #endif | |
| // printf("Status: %08lx\n", (LI)set->status); | |
| // decFloatShow(df, "final2"); | |
| return df; | |
| } // decFinalize | |
| /* ------------------------------------------------------------------ */ | |
| /* decFloatFromBCD -- set decFloat from exponent, BCD8, and sign */ | |
| /* */ | |
| /* df is the target decFloat */ | |
| /* exp is the in-range unbiased exponent, q, or a special value in */ | |
| /* the form returned by decFloatGetExponent */ | |
| /* bcdar holds DECPMAX digits to set the coefficient from, one */ | |
| /* digit in each byte (BCD8 encoding); the first (MSD) is ignored */ | |
| /* if df is a NaN; all are ignored if df is infinite. */ | |
| /* All bytes must be in 0-9; results are undefined otherwise. */ | |
| /* sig is DECFLOAT_Sign to set the sign bit, 0 otherwise */ | |
| /* returns df, which will be canonical */ | |
| /* */ | |
| /* No error is possible, and no status will be set. */ | |
| /* ------------------------------------------------------------------ */ | |
| decFloat * decFloatFromBCD(decFloat *df, Int exp, const uByte *bcdar, | |
| Int sig) { | |
| uInt encode, dpd; // work | |
| const uByte *ub; // .. | |
| if (EXPISSPECIAL(exp)) encode=exp|sig;// specials already encoded | |
| else { // is finite | |
| // encode the combination field and exponent continuation | |
| uInt uexp=(uInt)(exp+DECBIAS); // biased exponent | |
| uInt code=(uexp>>DECECONL)<<4; // top two bits of exp | |
| code+=bcdar[0]; // add msd | |
| // look up the combination field and make high word | |
| encode=DECCOMBFROM[code]|sig; // indexed by (0-2)*16+msd | |
| encode|=(uexp<<(32-6-DECECONL)) & 0x03ffffff; // exponent continuation | |
| } | |
| // private macro to extract a declet, n (where 0<=n<DECLETS and 0 | |
| // refers to the declet from the least significant three digits) | |
| // and put the corresponding DPD code into dpd. | |
| // Use of a working pointer, uInt *ub, is assumed. | |
| #define getDPDb(dpd, n) ub=bcdar+DECPMAX-1-(3*(n))-2; \ | |
| dpd=BCD2DPD[(*ub*256)+(*(ub+1)*16)+*(ub+2)]; | |
| // place the declets in the encoding words and copy to result (df), | |
| // according to endianness; in all cases complete the sign word | |
| // first | |
| #if DECPMAX==7 | |
| getDPDb(dpd, 1); | |
| encode|=dpd<<10; | |
| getDPDb(dpd, 0); | |
| encode|=dpd; | |
| DFWORD(df, 0)=encode; // just the one word | |
| #elif DECPMAX==16 | |
| getDPDb(dpd, 4); encode|=dpd<<8; | |
| getDPDb(dpd, 3); encode|=dpd>>2; | |
| DFWORD(df, 0)=encode; | |
| encode=dpd<<30; | |
| getDPDb(dpd, 2); encode|=dpd<<20; | |
| getDPDb(dpd, 1); encode|=dpd<<10; | |
| getDPDb(dpd, 0); encode|=dpd; | |
| DFWORD(df, 1)=encode; | |
| #elif DECPMAX==34 | |
| getDPDb(dpd,10); encode|=dpd<<4; | |
| getDPDb(dpd, 9); encode|=dpd>>6; | |
| DFWORD(df, 0)=encode; | |
| encode=dpd<<26; | |
| getDPDb(dpd, 8); encode|=dpd<<16; | |
| getDPDb(dpd, 7); encode|=dpd<<6; | |
| getDPDb(dpd, 6); encode|=dpd>>4; | |
| DFWORD(df, 1)=encode; | |
| encode=dpd<<28; | |
| getDPDb(dpd, 5); encode|=dpd<<18; | |
| getDPDb(dpd, 4); encode|=dpd<<8; | |
| getDPDb(dpd, 3); encode|=dpd>>2; | |
| DFWORD(df, 2)=encode; | |
| encode=dpd<<30; | |
| getDPDb(dpd, 2); encode|=dpd<<20; | |
| getDPDb(dpd, 1); encode|=dpd<<10; | |
| getDPDb(dpd, 0); encode|=dpd; | |
| DFWORD(df, 3)=encode; | |
| #endif | |
| // decFloatShow(df, "fromB"); | |
| return df; | |
| } // decFloatFromBCD | |
| /* ------------------------------------------------------------------ */ | |
| /* decFloatFromPacked -- set decFloat from exponent and packed BCD */ | |
| /* */ | |
| /* df is the target decFloat */ | |
| /* exp is the in-range unbiased exponent, q, or a special value in */ | |
| /* the form returned by decFloatGetExponent */ | |
| /* packed holds DECPMAX packed decimal digits plus a sign nibble */ | |
| /* (all 6 codes are OK); the first (MSD) is ignored if df is a NaN */ | |
| /* and all except sign are ignored if df is infinite. For DOUBLE */ | |
| /* and QUAD the first (pad) nibble is also ignored in all cases. */ | |
| /* All coefficient nibbles must be in 0-9 and sign in A-F; results */ | |
| /* are undefined otherwise. */ | |
| /* returns df, which will be canonical */ | |
| /* */ | |
| /* No error is possible, and no status will be set. */ | |
| /* ------------------------------------------------------------------ */ | |
| decFloat * decFloatFromPacked(decFloat *df, Int exp, const uByte *packed) { | |
| uByte bcdar[DECPMAX+2]; // work [+1 for pad, +1 for sign] | |
| const uByte *ip; // .. | |
| uByte *op; // .. | |
| Int sig=0; // sign | |
| // expand coefficient and sign to BCDAR | |
| #if SINGLE | |
| op=bcdar+1; // no pad digit | |
| #else | |
| op=bcdar; // first (pad) digit ignored | |
| #endif | |
| for (ip=packed; ip<packed+((DECPMAX+2)/2); ip++) { | |
| *op++=*ip>>4; | |
| *op++=(uByte)(*ip&0x0f); // [final nibble is sign] | |
| } | |
| op--; // -> sign byte | |
| if (*op==DECPMINUS || *op==DECPMINUSALT) sig=DECFLOAT_Sign; | |
| if (EXPISSPECIAL(exp)) { // Infinity or NaN | |
| if (!EXPISINF(exp)) bcdar[1]=0; // a NaN: ignore MSD | |
| else memset(bcdar+1, 0, DECPMAX); // Infinite: coefficient to 0 | |
| } | |
| return decFloatFromBCD(df, exp, bcdar+1, sig); | |
| } // decFloatFromPacked | |
| /* ------------------------------------------------------------------ */ | |
| /* decFloatFromPackedChecked -- set from exponent and packed; checked */ | |
| /* */ | |
| /* df is the target decFloat */ | |
| /* exp is the in-range unbiased exponent, q, or a special value in */ | |
| /* the form returned by decFloatGetExponent */ | |
| /* packed holds DECPMAX packed decimal digits plus a sign nibble */ | |
| /* (all 6 codes are OK); the first (MSD) must be 0 if df is a NaN */ | |
| /* and all digits must be 0 if df is infinite. For DOUBLE and */ | |
| /* QUAD the first (pad) nibble must be 0. */ | |
| /* All coefficient nibbles must be in 0-9 and sign in A-F. */ | |
| /* returns df, which will be canonical or NULL if any of the */ | |
| /* requirements are not met (if this case df is unchanged); that */ | |
| /* is, the input data must be as returned by decFloatToPacked, */ | |
| /* except that all six sign codes are acccepted. */ | |
| /* */ | |
| /* No status will be set. */ | |
| /* ------------------------------------------------------------------ */ | |
| decFloat * decFloatFromPackedChecked(decFloat *df, Int exp, | |
| const uByte *packed) { | |
| uByte bcdar[DECPMAX+2]; // work [+1 for pad, +1 for sign] | |
| const uByte *ip; // .. | |
| uByte *op; // .. | |
| Int sig=0; // sign | |
| // expand coefficient and sign to BCDAR | |
| #if SINGLE | |
| op=bcdar+1; // no pad digit | |
| #else | |
| op=bcdar; // first (pad) digit here | |
| #endif | |
| for (ip=packed; ip<packed+((DECPMAX+2)/2); ip++) { | |
| *op=*ip>>4; | |
| if (*op>9) return NULL; | |
| op++; | |
| *op=(uByte)(*ip&0x0f); // [final nibble is sign] | |
| if (*op>9 && ip<packed+((DECPMAX+2)/2)-1) return NULL; | |
| op++; | |
| } | |
| op--; // -> sign byte | |
| if (*op<=9) return NULL; // bad sign | |
| if (*op==DECPMINUS || *op==DECPMINUSALT) sig=DECFLOAT_Sign; | |
| #if !SINGLE | |
| if (bcdar[0]!=0) return NULL; // bad pad nibble | |
| #endif | |
| if (EXPISNAN(exp)) { // a NaN | |
| if (bcdar[1]!=0) return NULL; // bad msd | |
| } // NaN | |
| else if (EXPISINF(exp)) { // is infinite | |
| Int i; | |
| for (i=0; i<DECPMAX; i++) { | |
| if (bcdar[i+1]!=0) return NULL; // should be all zeros | |
| } | |
| } // infinity | |
| else { // finite | |
| // check the exponent is in range | |
| if (exp>DECEMAX-DECPMAX+1) return NULL; | |
| if (exp<DECEMIN-DECPMAX+1) return NULL; | |
| } | |
| return decFloatFromBCD(df, exp, bcdar+1, sig); | |
| } // decFloatFromPacked | |
| /* ------------------------------------------------------------------ */ | |
| /* decFloatFromString -- conversion from numeric string */ | |
| /* */ | |
| /* result is the decFloat format number which gets the result of */ | |
| /* the conversion */ | |
| /* *string is the character string which should contain a valid */ | |
| /* number (which may be a special value), \0-terminated */ | |
| /* If there are too many significant digits in the */ | |
| /* coefficient it will be rounded. */ | |
| /* set is the context */ | |
| /* returns result */ | |
| /* */ | |
| /* The length of the coefficient and the size of the exponent are */ | |
| /* checked by this routine, so the correct error (Underflow or */ | |
| /* Overflow) can be reported or rounding applied, as necessary. */ | |
| /* */ | |
| /* There is no limit to the coefficient length for finite inputs; */ | |
| /* NaN payloads must be integers with no more than DECPMAX-1 digits. */ | |
| /* Exponents may have up to nine significant digits. */ | |
| /* */ | |
| /* If bad syntax is detected, the result will be a quiet NaN. */ | |
| /* ------------------------------------------------------------------ */ | |
| decFloat * decFloatFromString(decFloat *result, const char *string, | |
| decContext *set) { | |
| Int digits; // count of digits in coefficient | |
| const char *dotchar=NULL; // where dot was found [NULL if none] | |
| const char *cfirst=string; // -> first character of decimal part | |
| const char *c; // work | |
| uByte *ub; // .. | |
| uInt uiwork; // for macros | |
| bcdnum num; // collects data for finishing | |
| uInt error=DEC_Conversion_syntax; // assume the worst | |
| uByte buffer[ROUNDUP(DECSTRING+11, 8)]; // room for most coefficents, | |
| // some common rounding, +3, & pad | |
| #if DECTRACE | |
| // printf("FromString %s ...\n", string); | |
| #endif | |
| for(;;) { // once-only 'loop' | |
| num.sign=0; // assume non-negative | |
| num.msd=buffer; // MSD is here always | |
| // detect and validate the coefficient, including any leading, | |
| // trailing, or embedded '.' | |
| // [could test four-at-a-time here (saving 10% for decQuads), | |
| // but that risks storage violation because the position of the | |
| // terminator is unknown] | |
| for (c=string;; c++) { // -> input character | |
| if (((unsigned)(*c-'0'))<=9) continue; // '0' through '9' is good | |
| if (*c=='\0') break; // most common non-digit | |
| if (*c=='.') { | |
| if (dotchar!=NULL) break; // not first '.' | |
| dotchar=c; // record offset into decimal part | |
| continue;} | |
| if (c==string) { // first in string... | |
| if (*c=='-') { // valid - sign | |
| cfirst++; | |
| num.sign=DECFLOAT_Sign; | |
| continue;} | |
| if (*c=='+') { // valid + sign | |
| cfirst++; | |
| continue;} | |
| } | |
| // *c is not a digit, terminator, or a valid +, -, or '.' | |
| break; | |
| } // c loop | |
| digits=(uInt)(c-cfirst); // digits (+1 if a dot) | |
| if (digits>0) { // had digits and/or dot | |
| const char *clast=c-1; // note last coefficient char position | |
| Int exp=0; // exponent accumulator | |
| if (*c!='\0') { // something follows the coefficient | |
| uInt edig; // unsigned work | |
| // had some digits and more to come; expect E[+|-]nnn now | |
| const char *firstexp; // exponent first non-zero | |
| if (*c!='E' && *c!='e') break; | |
| c++; // to (optional) sign | |
| if (*c=='-' || *c=='+') c++; // step over sign (c=clast+2) | |
| if (*c=='\0') break; // no digits! (e.g., '1.2E') | |
| for (; *c=='0';) c++; // skip leading zeros [even last] | |
| firstexp=c; // remember start [maybe '\0'] | |
| // gather exponent digits | |
| edig=(uInt)*c-(uInt)'0'; | |
| if (edig<=9) { // [check not bad or terminator] | |
| exp+=edig; // avoid initial X10 | |
| c++; | |
| for (;; c++) { | |
| edig=(uInt)*c-(uInt)'0'; | |
| if (edig>9) break; | |
| exp=exp*10+edig; | |
| } | |
| } | |
| // if not now on the '\0', *c must not be a digit | |
| if (*c!='\0') break; | |
| // (this next test must be after the syntax checks) | |
| // if definitely more than the possible digits for format then | |
| // the exponent may have wrapped, so simply set it to a certain | |
| // over/underflow value | |
| if (c>firstexp+DECEMAXD) exp=DECEMAX*2; | |
| if (*(clast+2)=='-') exp=-exp; // was negative | |
| } // exponent part | |
| if (dotchar!=NULL) { // had a '.' | |
| digits--; // remove from digits count | |
| if (digits==0) break; // was dot alone: bad syntax | |
| exp-=(Int)(clast-dotchar); // adjust exponent | |
| // [the '.' can now be ignored] | |
| } | |
| num.exponent=exp; // exponent is good; store it | |
| // Here when whole string has been inspected and syntax is good | |
| // cfirst->first digit or dot, clast->last digit or dot | |
| error=0; // no error possible now | |
| // if the number of digits in the coefficient will fit in buffer | |
| // then it can simply be converted to bcd8 and copied -- decFinalize | |
| // will take care of leading zeros and rounding; the buffer is big | |
| // enough for all canonical coefficients, including 0.00000nn... | |
| ub=buffer; | |
| if (digits<=(Int)(sizeof(buffer)-3)) { // [-3 allows by-4s copy] | |
| c=cfirst; | |
| if (dotchar!=NULL) { // a dot to worry about | |
| if (*(c+1)=='.') { // common canonical case | |
| *ub++=(uByte)(*c-'0'); // copy leading digit | |
| c+=2; // prepare to handle rest | |
| } | |
| else for (; c<=clast;) { // '.' could be anywhere | |
| // as usual, go by fours when safe; NB it has been asserted | |
| // that a '.' does not have the same mask as a digit | |
| if (c<=clast-3 // safe for four | |
| && (UBTOUI(c)&0xf0f0f0f0)==CHARMASK) { // test four | |
| UBFROMUI(ub, UBTOUI(c)&0x0f0f0f0f); // to BCD8 | |
| ub+=4; | |
| c+=4; | |
| continue; | |
| } | |
| if (*c=='.') { // found the dot | |
| c++; // step over it .. | |
| break; // .. and handle the rest | |
| } | |
| *ub++=(uByte)(*c++-'0'); | |
| } | |
| } // had dot | |
| // Now no dot; do this by fours (where safe) | |
| for (; c<=clast-3; c+=4, ub+=4) UBFROMUI(ub, UBTOUI(c)&0x0f0f0f0f); | |
| for (; c<=clast; c++, ub++) *ub=(uByte)(*c-'0'); | |
| num.lsd=buffer+digits-1; // record new LSD | |
| } // fits | |
| else { // too long for buffer | |
| // [This is a rare and unusual case; arbitrary-length input] | |
| // strip leading zeros [but leave final 0 if all 0's] | |
| if (*cfirst=='.') cfirst++; // step past dot at start | |
| if (*cfirst=='0') { // [cfirst always -> digit] | |
| for (; cfirst<clast; cfirst++) { | |
| if (*cfirst!='0') { // non-zero found | |
| if (*cfirst=='.') continue; // [ignore] | |
| break; // done | |
| } | |
| digits--; // 0 stripped | |
| } // cfirst | |
| } // at least one leading 0 | |
| // the coefficient is now as short as possible, but may still | |
| // be too long; copy up to Pmax+1 digits to the buffer, then | |
| // just record any non-zeros (set round-for-reround digit) | |
| for (c=cfirst; c<=clast && ub<=buffer+DECPMAX; c++) { | |
| // (see commentary just above) | |
| if (c<=clast-3 // safe for four | |
| && (UBTOUI(c)&0xf0f0f0f0)==CHARMASK) { // four digits | |
| UBFROMUI(ub, UBTOUI(c)&0x0f0f0f0f); // to BCD8 | |
| ub+=4; | |
| c+=3; // [will become 4] | |
| continue; | |
| } | |
| if (*c=='.') continue; // [ignore] | |
| *ub++=(uByte)(*c-'0'); | |
| } | |
| ub--; // -> LSD | |
| for (; c<=clast; c++) { // inspect remaining chars | |
| if (*c!='0') { // sticky bit needed | |
| if (*c=='.') continue; // [ignore] | |
| *ub=DECSTICKYTAB[*ub]; // update round-for-reround | |
| break; // no need to look at more | |
| } | |
| } | |
| num.lsd=ub; // record LSD | |
| // adjust exponent for dropped digits | |
| num.exponent+=digits-(Int)(ub-buffer+1); | |
| } // too long for buffer | |
| } // digits and/or dot | |
| else { // no digits or dot were found | |
| // only Infinities and NaNs are allowed, here | |
| if (*c=='\0') break; // nothing there is bad | |
| buffer[0]=0; // default a coefficient of 0 | |
| num.lsd=buffer; // .. | |
| if (decBiStr(c, "infinity", "INFINITY") | |
| || decBiStr(c, "inf", "INF")) num.exponent=DECFLOAT_Inf; | |
| else { // should be a NaN | |
| num.exponent=DECFLOAT_qNaN; // assume quiet NaN | |
| if (*c=='s' || *c=='S') { // probably an sNaN | |
| num.exponent=DECFLOAT_sNaN; // effect the 's' | |
| c++; // and step over it | |
| } | |
| if (*c!='N' && *c!='n') break; // check caseless "NaN" | |
| c++; | |
| if (*c!='a' && *c!='A') break; // .. | |
| c++; | |
| if (*c!='N' && *c!='n') break; // .. | |
| c++; | |
| // now either nothing, or nnnn payload (no dots), expected | |
| // -> start of integer, and skip leading 0s [including plain 0] | |
| for (cfirst=c; *cfirst=='0';) cfirst++; | |
| if (*cfirst!='\0') { // not empty or all-0, payload | |
| // payload found; check all valid digits and copy to buffer as bcd8 | |
| ub=buffer; | |
| for (c=cfirst;; c++, ub++) { | |
| if ((unsigned)(*c-'0')>9) break; // quit if not 0-9 | |
| if (c-cfirst==DECPMAX-1) break; // too many digits | |
| *ub=(uByte)(*c-'0'); // good bcd8 | |
| } | |
| if (*c!='\0') break; // not all digits, or too many | |
| num.lsd=ub-1; // record new LSD | |
| } | |
| } // NaN or sNaN | |
| error=0; // syntax is OK | |
| } // digits=0 (special expected) | |
| break; // drop out | |
| } // [for(;;) once-loop] | |
| // decShowNum(&num, "fromStr"); | |
| if (error!=0) { | |
| set->status|=error; | |
| num.exponent=DECFLOAT_qNaN; // set up quiet NaN | |
| num.sign=0; // .. with 0 sign | |
| buffer[0]=0; // .. and coefficient | |
| num.lsd=buffer; // .. | |
| // decShowNum(&num, "oops"); | |
| } | |
| // decShowNum(&num, "dffs"); | |
| decFinalize(result, &num, set); // round, check, and lay out | |
| // decFloatShow(result, "fromString"); | |
| return result; | |
| } // decFloatFromString | |
| /* ------------------------------------------------------------------ */ | |
| /* decFloatFromWider -- conversion from next-wider format */ | |
| /* */ | |
| /* result is the decFloat format number which gets the result of */ | |
| /* the conversion */ | |
| /* wider is the decFloatWider format number which will be narrowed */ | |
| /* set is the context */ | |
| /* returns result */ | |
| /* */ | |
| /* Narrowing can cause rounding, overflow, etc., but not Invalid */ | |
| /* operation (sNaNs are copied and do not signal). */ | |
| /* ------------------------------------------------------------------ */ | |
| // narrow-to is not possible for decQuad format numbers; simply omit | |
| #if !QUAD | |
| decFloat * decFloatFromWider(decFloat *result, const decFloatWider *wider, | |
| decContext *set) { | |
| bcdnum num; // collects data for finishing | |
| uByte bcdar[DECWPMAX]; // room for wider coefficient | |
| uInt widerhi=DFWWORD(wider, 0); // top word | |
| Int exp; | |
| GETWCOEFF(wider, bcdar); | |
| num.msd=bcdar; // MSD is here always | |
| num.lsd=bcdar+DECWPMAX-1; // LSD is here always | |
| num.sign=widerhi&0x80000000; // extract sign [DECFLOAT_Sign=Neg] | |
| // decode the wider combination field to exponent | |
| exp=DECCOMBWEXP[widerhi>>26]; // decode from wider combination field | |
| // if it is a special there's nothing to do unless sNaN; if it's | |
| // finite then add the (wider) exponent continuation and unbias | |
| if (EXPISSPECIAL(exp)) exp=widerhi&0x7e000000; // include sNaN selector | |
| else exp+=GETWECON(wider)-DECWBIAS; | |
| num.exponent=exp; | |
| // decShowNum(&num, "dffw"); | |
| return decFinalize(result, &num, set);// round, check, and lay out | |
| } // decFloatFromWider | |
| #endif | |
| /* ------------------------------------------------------------------ */ | |
| /* decFloatGetCoefficient -- get coefficient as BCD8 */ | |
| /* */ | |
| /* df is the decFloat from which to extract the coefficient */ | |
| /* bcdar is where DECPMAX bytes will be written, one BCD digit in */ | |
| /* each byte (BCD8 encoding); if df is a NaN the first byte will */ | |
| /* be zero, and if it is infinite they will all be zero */ | |
| /* returns the sign of the coefficient (DECFLOAT_Sign if negative, */ | |
| /* 0 otherwise) */ | |
| /* */ | |
| /* No error is possible, and no status will be set. If df is a */ | |
| /* special value the array is set to zeros (for Infinity) or to the */ | |
| /* payload of a qNaN or sNaN. */ | |
| /* ------------------------------------------------------------------ */ | |
| Int decFloatGetCoefficient(const decFloat *df, uByte *bcdar) { | |
| if (DFISINF(df)) memset(bcdar, 0, DECPMAX); | |
| else { | |
| GETCOEFF(df, bcdar); // use macro | |
| if (DFISNAN(df)) bcdar[0]=0; // MSD needs correcting | |
| } | |
| return GETSIGN(df); | |
| } // decFloatGetCoefficient | |
| /* ------------------------------------------------------------------ */ | |
| /* decFloatGetExponent -- get unbiased exponent */ | |
| /* */ | |
| /* df is the decFloat from which to extract the exponent */ | |
| /* returns the exponent, q. */ | |
| /* */ | |
| /* No error is possible, and no status will be set. If df is a */ | |
| /* special value the first seven bits of the decFloat are returned, */ | |
| /* left adjusted and with the first (sign) bit set to 0 (followed by */ | |
| /* 25 0 bits). e.g., -sNaN would return 0x7e000000 (DECFLOAT_sNaN). */ | |
| /* ------------------------------------------------------------------ */ | |
| Int decFloatGetExponent(const decFloat *df) { | |
| if (DFISSPECIAL(df)) return DFWORD(df, 0)&0x7e000000; | |
| return GETEXPUN(df); | |
| } // decFloatGetExponent | |
| /* ------------------------------------------------------------------ */ | |
| /* decFloatSetCoefficient -- set coefficient from BCD8 */ | |
| /* */ | |
| /* df is the target decFloat (and source of exponent/special value) */ | |
| /* bcdar holds DECPMAX digits to set the coefficient from, one */ | |
| /* digit in each byte (BCD8 encoding); the first (MSD) is ignored */ | |
| /* if df is a NaN; all are ignored if df is infinite. */ | |
| /* sig is DECFLOAT_Sign to set the sign bit, 0 otherwise */ | |
| /* returns df, which will be canonical */ | |
| /* */ | |
| /* No error is possible, and no status will be set. */ | |
| /* ------------------------------------------------------------------ */ | |
| decFloat * decFloatSetCoefficient(decFloat *df, const uByte *bcdar, | |
| Int sig) { | |
| uInt exp; // for exponent | |
| uByte bcdzero[DECPMAX]; // for infinities | |
| // Exponent/special code is extracted from df | |
| if (DFISSPECIAL(df)) { | |
| exp=DFWORD(df, 0)&0x7e000000; | |
| if (DFISINF(df)) { | |
| memset(bcdzero, 0, DECPMAX); | |
| return decFloatFromBCD(df, exp, bcdzero, sig); | |
| } | |
| } | |
| else exp=GETEXPUN(df); | |
| return decFloatFromBCD(df, exp, bcdar, sig); | |
| } // decFloatSetCoefficient | |
| /* ------------------------------------------------------------------ */ | |
| /* decFloatSetExponent -- set exponent or special value */ | |
| /* */ | |
| /* df is the target decFloat (and source of coefficient/payload) */ | |
| /* set is the context for reporting status */ | |
| /* exp is the unbiased exponent, q, or a special value in the form */ | |
| /* returned by decFloatGetExponent */ | |
| /* returns df, which will be canonical */ | |
| /* */ | |
| /* No error is possible, but Overflow or Underflow might occur. */ | |
| /* ------------------------------------------------------------------ */ | |
| decFloat * decFloatSetExponent(decFloat *df, decContext *set, Int exp) { | |
| uByte bcdcopy[DECPMAX]; // for coefficient | |
| bcdnum num; // work | |
| num.exponent=exp; | |
| num.sign=decFloatGetCoefficient(df, bcdcopy); // extract coefficient | |
| if (DFISSPECIAL(df)) { // MSD or more needs correcting | |
| if (DFISINF(df)) memset(bcdcopy, 0, DECPMAX); | |
| bcdcopy[0]=0; | |
| } | |
| num.msd=bcdcopy; | |
| num.lsd=bcdcopy+DECPMAX-1; | |
| return decFinalize(df, &num, set); | |
| } // decFloatSetExponent | |
| /* ------------------------------------------------------------------ */ | |
| /* decFloatRadix -- returns the base (10) */ | |
| /* */ | |
| /* df is any decFloat of this format */ | |
| /* ------------------------------------------------------------------ */ | |
| uInt decFloatRadix(const decFloat *df) { | |
| if (df) return 10; // to placate compiler | |
| return 10; | |
| } // decFloatRadix | |
| /* The following function is not available if DECPRINT=0 */ | |
| #if DECPRINT | |
| /* ------------------------------------------------------------------ */ | |
| /* decFloatShow -- printf a decFloat in hexadecimal and decimal */ | |
| /* df is the decFloat to show */ | |
| /* tag is a tag string displayed with the number */ | |
| /* */ | |
| /* This is a debug aid; the precise format of the string may change. */ | |
| /* ------------------------------------------------------------------ */ | |
| void decFloatShow(const decFloat *df, const char *tag) { | |
| char hexbuf[DECBYTES*2+DECBYTES/4+1]; // NB blank after every fourth | |
| char buff[DECSTRING]; // for value in decimal | |
| Int i, j=0; | |
| for (i=0; i<DECBYTES; i++) { | |
| #if DECLITEND | |
| sprintf(&hexbuf[j], "%02x", df->bytes[DECBYTES-1-i]); | |
| #else | |
| sprintf(&hexbuf[j], "%02x", df->bytes[i]); | |
| #endif | |
| j+=2; | |
| // the next line adds blank (and terminator) after final pair, too | |
| if ((i+1)%4==0) {strcpy(&hexbuf[j], " "); j++;} | |
| } | |
| decFloatToString(df, buff); | |
| printf(">%s> %s [big-endian] %s\n", tag, hexbuf, buff); | |
| return; | |
| } // decFloatShow | |
| #endif | |
| /* ------------------------------------------------------------------ */ | |
| /* decFloatToBCD -- get sign, exponent, and BCD8 from a decFloat */ | |
| /* */ | |
| /* df is the source decFloat */ | |
| /* exp will be set to the unbiased exponent, q, or to a special */ | |
| /* value in the form returned by decFloatGetExponent */ | |
| /* bcdar is where DECPMAX bytes will be written, one BCD digit in */ | |
| /* each byte (BCD8 encoding); if df is a NaN the first byte will */ | |
| /* be zero, and if it is infinite they will all be zero */ | |
| /* returns the sign of the coefficient (DECFLOAT_Sign if negative, */ | |
| /* 0 otherwise) */ | |
| /* */ | |
| /* No error is possible, and no status will be set. */ | |
| /* ------------------------------------------------------------------ */ | |
| Int decFloatToBCD(const decFloat *df, Int *exp, uByte *bcdar) { | |
| if (DFISINF(df)) { | |
| memset(bcdar, 0, DECPMAX); | |
| *exp=DFWORD(df, 0)&0x7e000000; | |
| } | |
| else { | |
| GETCOEFF(df, bcdar); // use macro | |
| if (DFISNAN(df)) { | |
| bcdar[0]=0; // MSD needs correcting | |
| *exp=DFWORD(df, 0)&0x7e000000; | |
| } | |
| else { // finite | |
| *exp=GETEXPUN(df); | |
| } | |
| } | |
| return GETSIGN(df); | |
| } // decFloatToBCD | |
| /* ------------------------------------------------------------------ */ | |
| /* decFloatToEngString -- conversion to numeric string, engineering */ | |
| /* */ | |
| /* df is the decFloat format number to convert */ | |
| /* string is the string where the result will be laid out */ | |
| /* */ | |
| /* string must be at least DECPMAX+9 characters (the worst case is */ | |
| /* "-0.00000nnn...nnn\0", which is as long as the exponent form when */ | |
| /* DECEMAXD<=4); this condition is asserted above */ | |
| /* */ | |
| /* No error is possible, and no status will be set */ | |
| /* ------------------------------------------------------------------ */ | |
| char * decFloatToEngString(const decFloat *df, char *string){ | |
| uInt msd; // coefficient MSD | |
| Int exp; // exponent top two bits or full | |
| uInt comb; // combination field | |
| char *cstart; // coefficient start | |
| char *c; // output pointer in string | |
| char *s, *t; // .. (source, target) | |
| Int pre, e; // work | |
| const uByte *u; // .. | |
| uInt uiwork; // for macros [one compiler needs | |
| // volatile here to avoid bug, but | |
| // that doubles execution time] | |
| // Source words; macro handles endianness | |
| uInt sourhi=DFWORD(df, 0); // word with sign | |
| #if DECPMAX==16 | |
| uInt sourlo=DFWORD(df, 1); | |
| #elif DECPMAX==34 | |
| uInt sourmh=DFWORD(df, 1); | |
| uInt sourml=DFWORD(df, 2); | |
| uInt sourlo=DFWORD(df, 3); | |
| #endif | |
| c=string; // where result will go | |
| if (((Int)sourhi)<0) *c++='-'; // handle sign | |
| comb=sourhi>>26; // sign+combination field | |
| msd=DECCOMBMSD[comb]; // decode the combination field | |
| exp=DECCOMBEXP[comb]; // .. | |
| if (EXPISSPECIAL(exp)) { // special | |
| if (exp==DECFLOAT_Inf) { // infinity | |
| strcpy(c, "Inf"); | |
| strcpy(c+3, "inity"); | |
| return string; // easy | |
| } | |
| if (sourhi&0x02000000) *c++='s'; // sNaN | |
| strcpy(c, "NaN"); // complete word | |
| c+=3; // step past | |
| // quick exit if the payload is zero | |
| #if DECPMAX==7 | |
| if ((sourhi&0x000fffff)==0) return string; | |
| #elif DECPMAX==16 | |
| if (sourlo==0 && (sourhi&0x0003ffff)==0) return string; | |
| #elif DECPMAX==34 | |
| if (sourlo==0 && sourml==0 && sourmh==0 | |
| && (sourhi&0x00003fff)==0) return string; | |
| #endif | |
| // otherwise drop through to add integer; set correct exp etc. | |
| exp=0; msd=0; // setup for following code | |
| } | |
| else { // complete exponent; top two bits are in place | |
| exp+=GETECON(df)-DECBIAS; // .. + continuation and unbias | |
| } | |
| /* convert the digits of the significand to characters */ | |
| cstart=c; // save start of coefficient | |
| if (msd) *c++=(char)('0'+(char)msd); // non-zero most significant digit | |
| // Decode the declets. After extracting each declet, it is | |
| // decoded to a 4-uByte sequence by table lookup; the four uBytes | |
| // are the three encoded BCD8 digits followed by a 1-byte length | |
| // (significant digits, except that 000 has length 0). This allows | |
| // us to left-align the first declet with non-zero content, then | |
| // the remaining ones are full 3-char length. Fixed-length copies | |
| // are used because variable-length memcpy causes a subroutine call | |
| // in at least two compilers. (The copies are length 4 for speed | |
| // and are safe because the last item in the array is of length | |
| // three and has the length byte following.) | |
| #define dpd2char(dpdin) u=&DPD2BCD8[((dpdin)&0x3ff)*4]; \ | |
| if (c!=cstart) {UBFROMUI(c, UBTOUI(u)|CHARMASK); c+=3;} \ | |
| else if (*(u+3)) { \ | |
| UBFROMUI(c, UBTOUI(u+3-*(u+3))|CHARMASK); c+=*(u+3);} | |
| #if DECPMAX==7 | |
| dpd2char(sourhi>>10); // declet 1 | |
| dpd2char(sourhi); // declet 2 | |
| #elif DECPMAX==16 | |
| dpd2char(sourhi>>8); // declet 1 | |
| dpd2char((sourhi<<2) | (sourlo>>30)); // declet 2 | |
| dpd2char(sourlo>>20); // declet 3 | |
| dpd2char(sourlo>>10); // declet 4 | |
| dpd2char(sourlo); // declet 5 | |
| #elif DECPMAX==34 | |
| dpd2char(sourhi>>4); // declet 1 | |
| dpd2char((sourhi<<6) | (sourmh>>26)); // declet 2 | |
| dpd2char(sourmh>>16); // declet 3 | |
| dpd2char(sourmh>>6); // declet 4 | |
| dpd2char((sourmh<<4) | (sourml>>28)); // declet 5 | |
| dpd2char(sourml>>18); // declet 6 | |
| dpd2char(sourml>>8); // declet 7 | |
| dpd2char((sourml<<2) | (sourlo>>30)); // declet 8 | |
| dpd2char(sourlo>>20); // declet 9 | |
| dpd2char(sourlo>>10); // declet 10 | |
| dpd2char(sourlo); // declet 11 | |
| #endif | |
| if (c==cstart) *c++='0'; // all zeros, empty -- make "0" | |
| if (exp==0) { // integer or NaN case -- easy | |
| *c='\0'; // terminate | |
| return string; | |
| } | |
| /* non-0 exponent */ | |
| e=0; // assume no E | |
| pre=(Int)(c-cstart)+exp; // length+exp [c->LSD+1] | |
| // [here, pre-exp is the digits count (==1 for zero)] | |
| if (exp>0 || pre<-5) { // need exponential form | |
| e=pre-1; // calculate E value | |
| pre=1; // assume one digit before '.' | |
| if (e!=0) { // engineering: may need to adjust | |
| Int adj; // adjustment | |
| // The C remainder operator is undefined for negative numbers, so | |
| // a positive remainder calculation must be used here | |
| if (e<0) { | |
| adj=(-e)%3; | |
| if (adj!=0) adj=3-adj; | |
| } | |
| else { // e>0 | |
| adj=e%3; | |
| } | |
| e=e-adj; | |
| // if dealing with zero still produce an exponent which is a | |
| // multiple of three, as expected, but there will only be the | |
| // one zero before the E, still. Otherwise note the padding. | |
| if (!DFISZERO(df)) pre+=adj; | |
| else { // is zero | |
| if (adj!=0) { // 0.00Esnn needed | |
| e=e+3; | |
| pre=-(2-adj); | |
| } | |
| } // zero | |
| } // engineering adjustment | |
| } // exponential form | |
| // printf("e=%ld pre=%ld exp=%ld\n", (LI)e, (LI)pre, (LI)exp); | |
| /* modify the coefficient, adding 0s, '.', and E+nn as needed */ | |
| if (pre>0) { // ddd.ddd (plain), perhaps with E | |
| // or dd00 padding for engineering | |
| char *dotat=cstart+pre; | |
| if (dotat<c) { // if embedded dot needed... | |
| // move by fours; there must be space for junk at the end | |
| // because there is still space for exponent | |
| s=dotat+ROUNDDOWN4(c-dotat); // source | |
| t=s+1; // target | |
| // open the gap [cannot use memcpy] | |
| for (; s>=dotat; s-=4, t-=4) UBFROMUI(t, UBTOUI(s)); | |
| *dotat='.'; | |
| c++; // length increased by one | |
| } // need dot? | |
| else for (; c<dotat; c++) *c='0'; // pad for engineering | |
| } // pre>0 | |
| else { | |
| /* -5<=pre<=0: here for plain 0.ddd or 0.000ddd forms (may have | |
| E, but only for 0.00E+3 kind of case -- with plenty of spare | |
| space in this case */ | |
| pre=-pre+2; // gap width, including "0." | |
| t=cstart+ROUNDDOWN4(c-cstart)+pre; // preferred first target point | |
| // backoff if too far to the right | |
| if (t>string+DECSTRING-5) t=string+DECSTRING-5; // adjust to fit | |
| // now shift the entire coefficient to the right, being careful not | |
| // to access to the left of string [cannot use memcpy] | |
| for (s=t-pre; s>=string; s-=4, t-=4) UBFROMUI(t, UBTOUI(s)); | |
| // for Quads and Singles there may be a character or two left... | |
| s+=3; // where next would come from | |
| for(; s>=cstart; s--, t--) *(t+3)=*(s); | |
| // now have fill 0. through 0.00000; use overlaps to avoid tests | |
| if (pre>=4) { | |
| memcpy(cstart+pre-4, "0000", 4); | |
| memcpy(cstart, "0.00", 4); | |
| } | |
| else { // 2 or 3 | |
| *(cstart+pre-1)='0'; | |
| memcpy(cstart, "0.", 2); | |
| } | |
| c+=pre; // to end | |
| } | |
| // finally add the E-part, if needed; it will never be 0, and has | |
| // a maximum length of 3 or 4 digits (asserted above) | |
| if (e!=0) { | |
| memcpy(c, "E+", 2); // starts with E, assume + | |
| c++; | |
| if (e<0) { | |
| *c='-'; // oops, need '-' | |
| e=-e; // uInt, please | |
| } | |
| c++; | |
| // Three-character exponents are easy; 4-character a little trickier | |
| #if DECEMAXD<=3 | |
| u=&BIN2BCD8[e*4]; // -> 3 digits + length byte | |
| // copy fixed 4 characters [is safe], starting at non-zero | |
| // and with character mask to convert BCD to char | |
| UBFROMUI(c, UBTOUI(u+3-*(u+3))|CHARMASK); | |
| c+=*(u+3); // bump pointer appropriately | |
| #elif DECEMAXD==4 | |
| if (e<1000) { // 3 (or fewer) digits case | |
| u=&BIN2BCD8[e*4]; // -> 3 digits + length byte | |
| UBFROMUI(c, UBTOUI(u+3-*(u+3))|CHARMASK); // [as above] | |
| c+=*(u+3); // bump pointer appropriately | |
| } | |
| else { // 4-digits | |
| Int thou=((e>>3)*1049)>>17; // e/1000 | |
| Int rem=e-(1000*thou); // e%1000 | |
| *c++=(char)('0'+(char)thou); // the thousands digit | |
| u=&BIN2BCD8[rem*4]; // -> 3 digits + length byte | |
| UBFROMUI(c, UBTOUI(u)|CHARMASK);// copy fixed 3+1 characters [is safe] | |
| c+=3; // bump pointer, always 3 digits | |
| } | |
| #endif | |
| } | |
| *c='\0'; // terminate | |
| //printf("res %s\n", string); | |
| return string; | |
| } // decFloatToEngString | |
| /* ------------------------------------------------------------------ */ | |
| /* decFloatToPacked -- convert decFloat to Packed decimal + exponent */ | |
| /* */ | |
| /* df is the source decFloat */ | |
| /* exp will be set to the unbiased exponent, q, or to a special */ | |
| /* value in the form returned by decFloatGetExponent */ | |
| /* packed is where DECPMAX nibbles will be written with the sign as */ | |
| /* final nibble (0x0c for +, 0x0d for -); a NaN has a first nibble */ | |
| /* of zero, and an infinity is all zeros. decDouble and decQuad */ | |
| /* have a additional leading zero nibble, leading to result */ | |
| /* lengths of 4, 9, and 18 bytes. */ | |
| /* returns the sign of the coefficient (DECFLOAT_Sign if negative, */ | |
| /* 0 otherwise) */ | |
| /* */ | |
| /* No error is possible, and no status will be set. */ | |
| /* ------------------------------------------------------------------ */ | |
| Int decFloatToPacked(const decFloat *df, Int *exp, uByte *packed) { | |
| uByte bcdar[DECPMAX+2]; // work buffer | |
| uByte *ip=bcdar, *op=packed; // work pointers | |
| if (DFISINF(df)) { | |
| memset(bcdar, 0, DECPMAX+2); | |
| *exp=DECFLOAT_Inf; | |
| } | |
| else { | |
| GETCOEFF(df, bcdar+1); // use macro | |
| if (DFISNAN(df)) { | |
| bcdar[1]=0; // MSD needs clearing | |
| *exp=DFWORD(df, 0)&0x7e000000; | |
| } | |
| else { // finite | |
| *exp=GETEXPUN(df); | |
| } | |
| } | |
| // now pack; coefficient currently at bcdar+1 | |
| #if SINGLE | |
| ip++; // ignore first byte | |
| #else | |
| *ip=0; // need leading zero | |
| #endif | |
| // set final byte to Packed BCD sign value | |
| bcdar[DECPMAX+1]=(DFISSIGNED(df) ? DECPMINUS : DECPPLUS); | |
| // pack an even number of bytes... | |
| for (; op<packed+((DECPMAX+2)/2); op++, ip+=2) { | |
| *op=(uByte)((*ip<<4)+*(ip+1)); | |
| } | |
| return (bcdar[DECPMAX+1]==DECPMINUS ? DECFLOAT_Sign : 0); | |
| } // decFloatToPacked | |
| /* ------------------------------------------------------------------ */ | |
| /* decFloatToString -- conversion to numeric string */ | |
| /* */ | |
| /* df is the decFloat format number to convert */ | |
| /* string is the string where the result will be laid out */ | |
| /* */ | |
| /* string must be at least DECPMAX+9 characters (the worst case is */ | |
| /* "-0.00000nnn...nnn\0", which is as long as the exponent form when */ | |
| /* DECEMAXD<=4); this condition is asserted above */ | |
| /* */ | |
| /* No error is possible, and no status will be set */ | |
| /* ------------------------------------------------------------------ */ | |
| char * decFloatToString(const decFloat *df, char *string){ | |
| uInt msd; // coefficient MSD | |
| Int exp; // exponent top two bits or full | |
| uInt comb; // combination field | |
| char *cstart; // coefficient start | |
| char *c; // output pointer in string | |
| char *s, *t; // .. (source, target) | |
| Int pre, e; // work | |
| const uByte *u; // .. | |
| uInt uiwork; // for macros [one compiler needs | |
| // volatile here to avoid bug, but | |
| // that doubles execution time] | |
| // Source words; macro handles endianness | |
| uInt sourhi=DFWORD(df, 0); // word with sign | |
| #if DECPMAX==16 | |
| uInt sourlo=DFWORD(df, 1); | |
| #elif DECPMAX==34 | |
| uInt sourmh=DFWORD(df, 1); | |
| uInt sourml=DFWORD(df, 2); | |
| uInt sourlo=DFWORD(df, 3); | |
| #endif | |
| c=string; // where result will go | |
| if (((Int)sourhi)<0) *c++='-'; // handle sign | |
| comb=sourhi>>26; // sign+combination field | |
| msd=DECCOMBMSD[comb]; // decode the combination field | |
| exp=DECCOMBEXP[comb]; // .. | |
| if (!EXPISSPECIAL(exp)) { // finite | |
| // complete exponent; top two bits are in place | |
| exp+=GETECON(df)-DECBIAS; // .. + continuation and unbias | |
| } | |
| else { // IS special | |
| if (exp==DECFLOAT_Inf) { // infinity | |
| strcpy(c, "Infinity"); | |
| return string; // easy | |
| } | |
| if (sourhi&0x02000000) *c++='s'; // sNaN | |
| strcpy(c, "NaN"); // complete word | |
| c+=3; // step past | |
| // quick exit if the payload is zero | |
| #if DECPMAX==7 | |
| if ((sourhi&0x000fffff)==0) return string; | |
| #elif DECPMAX==16 | |
| if (sourlo==0 && (sourhi&0x0003ffff)==0) return string; | |
| #elif DECPMAX==34 | |
| if (sourlo==0 && sourml==0 && sourmh==0 | |
| && (sourhi&0x00003fff)==0) return string; | |
| #endif | |
| // otherwise drop through to add integer; set correct exp etc. | |
| exp=0; msd=0; // setup for following code | |
| } | |
| /* convert the digits of the significand to characters */ | |
| cstart=c; // save start of coefficient | |
| if (msd) *c++=(char)('0'+(char)msd); // non-zero most significant digit | |
| // Decode the declets. After extracting each declet, it is | |
| // decoded to a 4-uByte sequence by table lookup; the four uBytes | |
| // are the three encoded BCD8 digits followed by a 1-byte length | |
| // (significant digits, except that 000 has length 0). This allows | |
| // us to left-align the first declet with non-zero content, then | |
| // the remaining ones are full 3-char length. Fixed-length copies | |
| // are used because variable-length memcpy causes a subroutine call | |
| // in at least two compilers. (The copies are length 4 for speed | |
| // and are safe because the last item in the array is of length | |
| // three and has the length byte following.) | |
| #define dpd2char(dpdin) u=&DPD2BCD8[((dpdin)&0x3ff)*4]; \ | |
| if (c!=cstart) {UBFROMUI(c, UBTOUI(u)|CHARMASK); c+=3;} \ | |
| else if (*(u+3)) { \ | |
| UBFROMUI(c, UBTOUI(u+3-*(u+3))|CHARMASK); c+=*(u+3);} | |
| #if DECPMAX==7 | |
| dpd2char(sourhi>>10); // declet 1 | |
| dpd2char(sourhi); // declet 2 | |
| #elif DECPMAX==16 | |
| dpd2char(sourhi>>8); // declet 1 | |
| dpd2char((sourhi<<2) | (sourlo>>30)); // declet 2 | |
| dpd2char(sourlo>>20); // declet 3 | |
| dpd2char(sourlo>>10); // declet 4 | |
| dpd2char(sourlo); // declet 5 | |
| #elif DECPMAX==34 | |
| dpd2char(sourhi>>4); // declet 1 | |
| dpd2char((sourhi<<6) | (sourmh>>26)); // declet 2 | |
| dpd2char(sourmh>>16); // declet 3 | |
| dpd2char(sourmh>>6); // declet 4 | |
| dpd2char((sourmh<<4) | (sourml>>28)); // declet 5 | |
| dpd2char(sourml>>18); // declet 6 | |
| dpd2char(sourml>>8); // declet 7 | |
| dpd2char((sourml<<2) | (sourlo>>30)); // declet 8 | |
| dpd2char(sourlo>>20); // declet 9 | |
| dpd2char(sourlo>>10); // declet 10 | |
| dpd2char(sourlo); // declet 11 | |
| #endif | |
| if (c==cstart) *c++='0'; // all zeros, empty -- make "0" | |
| //[This fast path is valid but adds 3-5 cycles to worst case length] | |
| //if (exp==0) { // integer or NaN case -- easy | |
| // *c='\0'; // terminate | |
| // return string; | |
| // } | |
| e=0; // assume no E | |
| pre=(Int)(c-cstart)+exp; // length+exp [c->LSD+1] | |
| // [here, pre-exp is the digits count (==1 for zero)] | |
| if (exp>0 || pre<-5) { // need exponential form | |
| e=pre-1; // calculate E value | |
| pre=1; // assume one digit before '.' | |
| } // exponential form | |
| /* modify the coefficient, adding 0s, '.', and E+nn as needed */ | |
| if (pre>0) { // ddd.ddd (plain), perhaps with E | |
| char *dotat=cstart+pre; | |
| if (dotat<c) { // if embedded dot needed... | |
| // [memmove is a disaster, here] | |
| // move by fours; there must be space for junk at the end | |
| // because exponent is still possible | |
| s=dotat+ROUNDDOWN4(c-dotat); // source | |
| t=s+1; // target | |
| // open the gap [cannot use memcpy] | |
| for (; s>=dotat; s-=4, t-=4) UBFROMUI(t, UBTOUI(s)); | |
| *dotat='.'; | |
| c++; // length increased by one | |
| } // need dot? | |
| // finally add the E-part, if needed; it will never be 0, and has | |
| // a maximum length of 3 or 4 digits (asserted above) | |
| if (e!=0) { | |
| memcpy(c, "E+", 2); // starts with E, assume + | |
| c++; | |
| if (e<0) { | |
| *c='-'; // oops, need '-' | |
| e=-e; // uInt, please | |
| } | |
| c++; | |
| // Three-character exponents are easy; 4-character a little trickier | |
| #if DECEMAXD<=3 | |
| u=&BIN2BCD8[e*4]; // -> 3 digits + length byte | |
| // copy fixed 4 characters [is safe], starting at non-zero | |
| // and with character mask to convert BCD to char | |
| UBFROMUI(c, UBTOUI(u+3-*(u+3))|CHARMASK); | |
| c+=*(u+3); // bump pointer appropriately | |
| #elif DECEMAXD==4 | |
| if (e<1000) { // 3 (or fewer) digits case | |
| u=&BIN2BCD8[e*4]; // -> 3 digits + length byte | |
| UBFROMUI(c, UBTOUI(u+3-*(u+3))|CHARMASK); // [as above] | |
| c+=*(u+3); // bump pointer appropriately | |
| } | |
| else { // 4-digits | |
| Int thou=((e>>3)*1049)>>17; // e/1000 | |
| Int rem=e-(1000*thou); // e%1000 | |
| *c++=(char)('0'+(char)thou); // the thousands digit | |
| u=&BIN2BCD8[rem*4]; // -> 3 digits + length byte | |
| UBFROMUI(c, UBTOUI(u)|CHARMASK); // copy fixed 3+1 characters [is safe] | |
| c+=3; // bump pointer, always 3 digits | |
| } | |
| #endif | |
| } | |
| *c='\0'; // add terminator | |
| //printf("res %s\n", string); | |
| return string; | |
| } // pre>0 | |
| /* -5<=pre<=0: here for plain 0.ddd or 0.000ddd forms (can never have E) */ | |
| // Surprisingly, this is close to being the worst-case path, so the | |
| // shift is done by fours; this is a little tricky because the | |
| // rightmost character to be written must not be beyond where the | |
| // rightmost terminator could be -- so backoff to not touch | |
| // terminator position if need be (this can make exact alignments | |
| // for full Doubles, but in some cases needs care not to access too | |
| // far to the left) | |
| pre=-pre+2; // gap width, including "0." | |
| t=cstart+ROUNDDOWN4(c-cstart)+pre; // preferred first target point | |
| // backoff if too far to the right | |
| if (t>string+DECSTRING-5) t=string+DECSTRING-5; // adjust to fit | |
| // now shift the entire coefficient to the right, being careful not | |
| // to access to the left of string [cannot use memcpy] | |
| for (s=t-pre; s>=string; s-=4, t-=4) UBFROMUI(t, UBTOUI(s)); | |
| // for Quads and Singles there may be a character or two left... | |
| s+=3; // where next would come from | |
| for(; s>=cstart; s--, t--) *(t+3)=*(s); | |
| // now have fill 0. through 0.00000; use overlaps to avoid tests | |
| if (pre>=4) { | |
| memcpy(cstart+pre-4, "0000", 4); | |
| memcpy(cstart, "0.00", 4); | |
| } | |
| else { // 2 or 3 | |
| *(cstart+pre-1)='0'; | |
| memcpy(cstart, "0.", 2); | |
| } | |
| *(c+pre)='\0'; // terminate | |
| return string; | |
| } // decFloatToString | |
| /* ------------------------------------------------------------------ */ | |
| /* decFloatToWider -- conversion to next-wider format */ | |
| /* */ | |
| /* source is the decFloat format number which gets the result of */ | |
| /* the conversion */ | |
| /* wider is the decFloatWider format number which will be narrowed */ | |
| /* returns wider */ | |
| /* */ | |
| /* Widening is always exact; no status is set (sNaNs are copied and */ | |
| /* do not signal). The result will be canonical if the source is, */ | |
| /* and may or may not be if the source is not. */ | |
| /* ------------------------------------------------------------------ */ | |
| // widening is not possible for decQuad format numbers; simply omit | |
| #if !QUAD | |
| decFloatWider * decFloatToWider(const decFloat *source, decFloatWider *wider) { | |
| uInt msd; | |
| /* Construct and copy the sign word */ | |
| if (DFISSPECIAL(source)) { | |
| // copy sign, combination, and first bit of exponent (sNaN selector) | |
| DFWWORD(wider, 0)=DFWORD(source, 0)&0xfe000000; | |
| msd=0; | |
| } | |
| else { // is finite number | |
| uInt exp=GETEXPUN(source)+DECWBIAS; // get unbiased exponent and rebias | |
| uInt code=(exp>>DECWECONL)<<29; // set two bits of exp [msd=0] | |
| code|=(exp<<(32-6-DECWECONL)) & 0x03ffffff; // add exponent continuation | |
| code|=DFWORD(source, 0)&0x80000000; // add sign | |
| DFWWORD(wider, 0)=code; // .. and place top word in wider | |
| msd=GETMSD(source); // get source coefficient MSD [0-9] | |
| } | |
| /* Copy the coefficient and clear any 'unused' words to left */ | |
| #if SINGLE | |
| DFWWORD(wider, 1)=(DFWORD(source, 0)&0x000fffff)|(msd<<20); | |
| #elif DOUBLE | |
| DFWWORD(wider, 2)=(DFWORD(source, 0)&0x0003ffff)|(msd<<18); | |
| DFWWORD(wider, 3)=DFWORD(source, 1); | |
| DFWWORD(wider, 1)=0; | |
| #endif | |
| return wider; | |
| } // decFloatToWider | |
| #endif | |
| /* ------------------------------------------------------------------ */ | |
| /* decFloatVersion -- return package version string */ | |
| /* */ | |
| /* returns a constant string describing this package */ | |
| /* ------------------------------------------------------------------ */ | |
| const char *decFloatVersion(void) { | |
| return DECVERSION; | |
| } // decFloatVersion | |
| /* ------------------------------------------------------------------ */ | |
| /* decFloatZero -- set to canonical (integer) zero */ | |
| /* */ | |
| /* df is the decFloat format number to integer +0 (q=0, c=+0) */ | |
| /* returns df */ | |
| /* */ | |
| /* No error is possible, and no status can be set. */ | |
| /* ------------------------------------------------------------------ */ | |
| decFloat * decFloatZero(decFloat *df){ | |
| DFWORD(df, 0)=ZEROWORD; // set appropriate top word | |
| #if DOUBLE || QUAD | |
| DFWORD(df, 1)=0; | |
| #if QUAD | |
| DFWORD(df, 2)=0; | |
| DFWORD(df, 3)=0; | |
| #endif | |
| #endif | |
| // decFloatShow(df, "zero"); | |
| return df; | |
| } // decFloatZero | |
| /* ------------------------------------------------------------------ */ | |
| /* Private generic function (not format-specific) for development use */ | |
| /* ------------------------------------------------------------------ */ | |
| // This is included once only, for all to use | |
| #if QUAD && (DECCHECK || DECTRACE) | |
| /* ---------------------------------------------------------------- */ | |
| /* decShowNum -- display bcd8 number in debug form */ | |
| /* */ | |
| /* num is the bcdnum to display */ | |
| /* tag is a string to label the display */ | |
| /* ---------------------------------------------------------------- */ | |
| void decShowNum(const bcdnum *num, const char *tag) { | |
| const char *csign="+"; // sign character | |
| uByte *ub; // work | |
| uInt uiwork; // for macros | |
| if (num->sign==DECFLOAT_Sign) csign="-"; | |
| printf(">%s> ", tag); | |
| if (num->exponent==DECFLOAT_Inf) printf("%sInfinity", csign); | |
| else if (num->exponent==DECFLOAT_qNaN) printf("%sqNaN", csign); | |
| else if (num->exponent==DECFLOAT_sNaN) printf("%ssNaN", csign); | |
| else { // finite | |
| char qbuf[10]; // for right-aligned q | |
| char *c; // work | |
| const uByte *u; // .. | |
| Int e=num->exponent; // .. exponent | |
| strcpy(qbuf, "q="); | |
| c=&qbuf[2]; // where exponent will go | |
| // lay out the exponent | |
| if (e<0) { | |
| *c++='-'; // add '-' | |
| e=-e; // uInt, please | |
| } | |
| #if DECEMAXD>4 | |
| #error Exponent form is too long for ShowNum to lay out | |
| #endif | |
| if (e==0) *c++='0'; // 0-length case | |
| else if (e<1000) { // 3 (or fewer) digits case | |
| u=&BIN2BCD8[e*4]; // -> 3 digits + length byte | |
| UBFROMUI(c, UBTOUI(u+3-*(u+3))|CHARMASK); // [as above] | |
| c+=*(u+3); // bump pointer appropriately | |
| } | |
| else { // 4-digits | |
| Int thou=((e>>3)*1049)>>17; // e/1000 | |
| Int rem=e-(1000*thou); // e%1000 | |
| *c++=(char)('0'+(char)thou); // the thousands digit | |
| u=&BIN2BCD8[rem*4]; // -> 3 digits + length byte | |
| UBFROMUI(c, UBTOUI(u)|CHARMASK); // copy fixed 3+1 characters [is safe] | |
| c+=3; // bump pointer, always 3 digits | |
| } | |
| *c='\0'; // add terminator | |
| printf("%7s c=%s", qbuf, csign); | |
| } | |
| if (!EXPISSPECIAL(num->exponent) || num->msd!=num->lsd || *num->lsd!=0) { | |
| for (ub=num->msd; ub<=num->lsd; ub++) { // coefficient... | |
| printf("%1x", *ub); | |
| if ((num->lsd-ub)%3==0 && ub!=num->lsd) printf(" "); // 4-space | |
| } | |
| } | |
| printf("\n"); | |
| } // decShowNum | |
| #endif |