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Diffstat (limited to 'gcc-4.7/libdecnumber/decCommon.c')
| -rw-r--r-- | gcc-4.7/libdecnumber/decCommon.c | 1847 |
1 files changed, 1847 insertions, 0 deletions
diff --git a/gcc-4.7/libdecnumber/decCommon.c b/gcc-4.7/libdecnumber/decCommon.c new file mode 100644 index 000000000..add1f2ed7 --- /dev/null +++ b/gcc-4.7/libdecnumber/decCommon.c @@ -0,0 +1,1847 @@ +/* Common code for fixed-size types in the decNumber C Library. + Copyright (C) 2007, 2009 Free Software Foundation, Inc. + Contributed by IBM Corporation. Author Mike Cowlishaw. + + This file is part of GCC. + + GCC is free software; you can redistribute it and/or modify it under + the terms of the GNU General Public License as published by the Free + Software Foundation; either version 3, or (at your option) any later + version. + + GCC is distributed in the hope that it will be useful, but WITHOUT ANY + WARRANTY; without even the implied warranty of MERCHANTABILITY or + FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + for more details. + +Under Section 7 of GPL version 3, you are granted additional +permissions described in the GCC Runtime Library Exception, version +3.1, as published by the Free Software Foundation. + +You should have received a copy of the GNU General Public License and +a copy of the GCC Runtime Library Exception along with this program; +see the files COPYING3 and COPYING.RUNTIME respectively. If not, see +<http://www.gnu.org/licenses/>. */ + +/* ------------------------------------------------------------------ */ +/* decCommon.c -- common code for all three fixed-size types */ +/* ------------------------------------------------------------------ */ +/* 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. */ + +#include "decCommonSymbols.h" + +/* 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 */ + } /* digits>0 */ + + 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 or dot */ + + else { /* no digits or dot were found */ + if (*c=='\0') break; /* nothing to come is bad */ + /* only Infinities and NaNs are allowed, here */ + 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 */ + c++; + num.exponent=DECFLOAT_sNaN; /* assume is in fact sNaN */ + } + 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 */ + break; /* done with specials */ + } /* digits=0 (special expected) */ + break; + } /* [for(;;) break] */ + + /* 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 DFISSIGNED(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 */ + +#if (DECCHECK || DECTRACE) +/* ------------------------------------------------------------------ */ +/* 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 DFISSIGNED(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 |