/* Common code for fixed-size types in the decNumber C Library.

/* Common code for fixed-size types in the decNumber C Library.
Copyright (C) 2007-2018 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 accepted. */
/* */
/* 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