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[/] [openrisc/] [tags/] [gnu-src/] [gcc-4.5.1/] [gcc-4.5.1-or32-1.0rc3/] [libdecnumber/] [dpd/] [decimal64.c] - Rev 516
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/* Decimal 64-bit format module for the decNumber C Library. Copyright (C) 2005, 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/>. */ /* ------------------------------------------------------------------ */ /* Decimal 64-bit format module */ /* ------------------------------------------------------------------ */ /* This module comprises the routines for decimal64 format numbers. */ /* Conversions are supplied to and from decNumber and String. */ /* */ /* This is used when decNumber provides operations, either for all */ /* operations or as a proxy between decNumber and decSingle. */ /* */ /* Error handling is the same as decNumber (qv.). */ /* ------------------------------------------------------------------ */ #include <string.h> /* [for memset/memcpy] */ #include <stdio.h> /* [for printf] */ #include "dconfig.h" /* GCC definitions */ #define DECNUMDIGITS 16 /* make decNumbers with space for 16 */ #include "decNumber.h" /* base number library */ #include "decNumberLocal.h" /* decNumber local types, etc. */ #include "decimal64.h" /* our primary include */ /* Utility routines and tables [in decimal64.c]; externs for C++ */ extern const uInt COMBEXP[32], COMBMSD[32]; extern const uShort DPD2BIN[1024]; extern const uShort BIN2DPD[1000]; extern const uByte BIN2CHAR[4001]; extern void decDigitsFromDPD(decNumber *, const uInt *, Int); extern void decDigitsToDPD(const decNumber *, uInt *, Int); #if DECTRACE || DECCHECK void decimal64Show(const decimal64 *); /* for debug */ extern void decNumberShow(const decNumber *); /* .. */ #endif /* Useful macro */ /* Clear a structure (e.g., a decNumber) */ #define DEC_clear(d) memset(d, 0, sizeof(*d)) /* define and include the tables to use for conversions */ #define DEC_BIN2CHAR 1 #define DEC_DPD2BIN 1 #define DEC_BIN2DPD 1 /* used for all sizes */ #include "decDPD.h" /* lookup tables */ /* ------------------------------------------------------------------ */ /* decimal64FromNumber -- convert decNumber to decimal64 */ /* */ /* ds is the target decimal64 */ /* dn is the source number (assumed valid) */ /* set is the context, used only for reporting errors */ /* */ /* The set argument is used only for status reporting and for the */ /* rounding mode (used if the coefficient is more than DECIMAL64_Pmax */ /* digits or an overflow is detected). If the exponent is out of the */ /* valid range then Overflow or Underflow will be raised. */ /* After Underflow a subnormal result is possible. */ /* */ /* DEC_Clamped is set if the number has to be 'folded down' to fit, */ /* by reducing its exponent and multiplying the coefficient by a */ /* power of ten, or if the exponent on a zero had to be clamped. */ /* ------------------------------------------------------------------ */ decimal64 * decimal64FromNumber(decimal64 *d64, const decNumber *dn, decContext *set) { uInt status=0; /* status accumulator */ Int ae; /* adjusted exponent */ decNumber dw; /* work */ decContext dc; /* .. */ uInt comb, exp; /* .. */ uInt uiwork; /* for macros */ uInt targar[2]={0, 0}; /* target 64-bit */ #define targhi targar[1] /* name the word with the sign */ #define targlo targar[0] /* and the other */ /* If the number has too many digits, or the exponent could be */ /* out of range then reduce the number under the appropriate */ /* constraints. This could push the number to Infinity or zero, */ /* so this check and rounding must be done before generating the */ /* decimal64] */ ae=dn->exponent+dn->digits-1; /* [0 if special] */ if (dn->digits>DECIMAL64_Pmax /* too many digits */ || ae>DECIMAL64_Emax /* likely overflow */ || ae<DECIMAL64_Emin) { /* likely underflow */ decContextDefault(&dc, DEC_INIT_DECIMAL64); /* [no traps] */ dc.round=set->round; /* use supplied rounding */ decNumberPlus(&dw, dn, &dc); /* (round and check) */ /* [this changes -0 to 0, so enforce the sign...] */ dw.bits|=dn->bits&DECNEG; status=dc.status; /* save status */ dn=&dw; /* use the work number */ } /* maybe out of range */ if (dn->bits&DECSPECIAL) { /* a special value */ if (dn->bits&DECINF) targhi=DECIMAL_Inf<<24; else { /* sNaN or qNaN */ if ((*dn->lsu!=0 || dn->digits>1) /* non-zero coefficient */ && (dn->digits<DECIMAL64_Pmax)) { /* coefficient fits */ decDigitsToDPD(dn, targar, 0); } if (dn->bits&DECNAN) targhi|=DECIMAL_NaN<<24; else targhi|=DECIMAL_sNaN<<24; } /* a NaN */ } /* special */ else { /* is finite */ if (decNumberIsZero(dn)) { /* is a zero */ /* set and clamp exponent */ if (dn->exponent<-DECIMAL64_Bias) { exp=0; /* low clamp */ status|=DEC_Clamped; } else { exp=dn->exponent+DECIMAL64_Bias; /* bias exponent */ if (exp>DECIMAL64_Ehigh) { /* top clamp */ exp=DECIMAL64_Ehigh; status|=DEC_Clamped; } } comb=(exp>>5) & 0x18; /* msd=0, exp top 2 bits .. */ } else { /* non-zero finite number */ uInt msd; /* work */ Int pad=0; /* coefficient pad digits */ /* the dn is known to fit, but it may need to be padded */ exp=(uInt)(dn->exponent+DECIMAL64_Bias); /* bias exponent */ if (exp>DECIMAL64_Ehigh) { /* fold-down case */ pad=exp-DECIMAL64_Ehigh; exp=DECIMAL64_Ehigh; /* [to maximum] */ status|=DEC_Clamped; } /* fastpath common case */ if (DECDPUN==3 && pad==0) { uInt dpd[6]={0,0,0,0,0,0}; uInt i; Int d=dn->digits; for (i=0; d>0; i++, d-=3) dpd[i]=BIN2DPD[dn->lsu[i]]; targlo =dpd[0]; targlo|=dpd[1]<<10; targlo|=dpd[2]<<20; if (dn->digits>6) { targlo|=dpd[3]<<30; targhi =dpd[3]>>2; targhi|=dpd[4]<<8; } msd=dpd[5]; /* [did not really need conversion] */ } else { /* general case */ decDigitsToDPD(dn, targar, pad); /* save and clear the top digit */ msd=targhi>>18; targhi&=0x0003ffff; } /* create the combination field */ if (msd>=8) comb=0x18 | ((exp>>7) & 0x06) | (msd & 0x01); else comb=((exp>>5) & 0x18) | msd; } targhi|=comb<<26; /* add combination field .. */ targhi|=(exp&0xff)<<18; /* .. and exponent continuation */ } /* finite */ if (dn->bits&DECNEG) targhi|=0x80000000; /* add sign bit */ /* now write to storage; this is now always endian */ if (DECLITEND) { /* lo int then hi */ UBFROMUI(d64->bytes, targar[0]); UBFROMUI(d64->bytes+4, targar[1]); } else { /* hi int then lo */ UBFROMUI(d64->bytes, targar[1]); UBFROMUI(d64->bytes+4, targar[0]); } if (status!=0) decContextSetStatus(set, status); /* pass on status */ /* decimal64Show(d64); */ return d64; } /* decimal64FromNumber */ /* ------------------------------------------------------------------ */ /* decimal64ToNumber -- convert decimal64 to decNumber */ /* d64 is the source decimal64 */ /* dn is the target number, with appropriate space */ /* No error is possible. */ /* ------------------------------------------------------------------ */ decNumber * decimal64ToNumber(const decimal64 *d64, decNumber *dn) { uInt msd; /* coefficient MSD */ uInt exp; /* exponent top two bits */ uInt comb; /* combination field */ Int need; /* work */ uInt uiwork; /* for macros */ uInt sourar[2]; /* source 64-bit */ #define sourhi sourar[1] /* name the word with the sign */ #define sourlo sourar[0] /* and the lower word */ /* load source from storage; this is endian */ if (DECLITEND) { sourlo=UBTOUI(d64->bytes ); /* directly load the low int */ sourhi=UBTOUI(d64->bytes+4); /* then the high int */ } else { sourhi=UBTOUI(d64->bytes ); /* directly load the high int */ sourlo=UBTOUI(d64->bytes+4); /* then the low int */ } comb=(sourhi>>26)&0x1f; /* combination field */ decNumberZero(dn); /* clean number */ if (sourhi&0x80000000) dn->bits=DECNEG; /* set sign if negative */ msd=COMBMSD[comb]; /* decode the combination field */ exp=COMBEXP[comb]; /* .. */ if (exp==3) { /* is a special */ if (msd==0) { dn->bits|=DECINF; return dn; /* no coefficient needed */ } else if (sourhi&0x02000000) dn->bits|=DECSNAN; else dn->bits|=DECNAN; msd=0; /* no top digit */ } else { /* is a finite number */ dn->exponent=(exp<<8)+((sourhi>>18)&0xff)-DECIMAL64_Bias; /* unbiased */ } /* get the coefficient */ sourhi&=0x0003ffff; /* clean coefficient continuation */ if (msd) { /* non-zero msd */ sourhi|=msd<<18; /* prefix to coefficient */ need=6; /* process 6 declets */ } else { /* msd=0 */ if (!sourhi) { /* top word 0 */ if (!sourlo) return dn; /* easy: coefficient is 0 */ need=3; /* process at least 3 declets */ if (sourlo&0xc0000000) need++; /* process 4 declets */ /* [could reduce some more, here] */ } else { /* some bits in top word, msd=0 */ need=4; /* process at least 4 declets */ if (sourhi&0x0003ff00) need++; /* top declet!=0, process 5 */ } } /*msd=0 */ decDigitsFromDPD(dn, sourar, need); /* process declets */ return dn; } /* decimal64ToNumber */ /* ------------------------------------------------------------------ */ /* to-scientific-string -- conversion to numeric string */ /* to-engineering-string -- conversion to numeric string */ /* */ /* decimal64ToString(d64, string); */ /* decimal64ToEngString(d64, string); */ /* */ /* d64 is the decimal64 format number to convert */ /* string is the string where the result will be laid out */ /* */ /* string must be at least 24 characters */ /* */ /* No error is possible, and no status can be set. */ /* ------------------------------------------------------------------ */ char * decimal64ToEngString(const decimal64 *d64, char *string){ decNumber dn; /* work */ decimal64ToNumber(d64, &dn); decNumberToEngString(&dn, string); return string; } /* decimal64ToEngString */ char * decimal64ToString(const decimal64 *d64, 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 */ const uByte *u; /* work */ char *s, *t; /* .. (source, target) */ Int dpd; /* .. */ Int pre, e; /* .. */ uInt uiwork; /* for macros */ uInt sourar[2]; /* source 64-bit */ #define sourhi sourar[1] /* name the word with the sign */ #define sourlo sourar[0] /* and the lower word */ /* load source from storage; this is endian */ if (DECLITEND) { sourlo=UBTOUI(d64->bytes ); /* directly load the low int */ sourhi=UBTOUI(d64->bytes+4); /* then the high int */ } else { sourhi=UBTOUI(d64->bytes ); /* directly load the high int */ sourlo=UBTOUI(d64->bytes+4); /* then the low int */ } c=string; /* where result will go */ if (((Int)sourhi)<0) *c++='-'; /* handle sign */ comb=(sourhi>>26)&0x1f; /* combination field */ msd=COMBMSD[comb]; /* decode the combination field */ exp=COMBEXP[comb]; /* .. */ if (exp==3) { if (msd==0) { /* 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 */ if (sourlo==0 && (sourhi&0x0003ffff)==0) return string; /* zero payload */ /* otherwise drop through to add integer; set correct exp */ exp=0; msd=0; /* setup for following code */ } else exp=(exp<<8)+((sourhi>>18)&0xff)-DECIMAL64_Bias; /* convert 16 digits of significand to characters */ cstart=c; /* save start of coefficient */ if (msd) *c++='0'+(char)msd; /* non-zero most significant digit */ /* Now decode the declets. After extracting each one, it is */ /* decoded to binary and then to a 4-char sequence by table lookup; */ /* the 4-chars are a 1-char length (significant digits, except 000 */ /* has length 0). This allows us to left-align the first declet */ /* with non-zero content, then remaining ones are full 3-char */ /* length. We use fixed-length memcpys because variable-length */ /* causes a subroutine call in GCC. (These are length 4 for speed */ /* and are safe because the array has an extra terminator byte.) */ #define dpd2char u=&BIN2CHAR[DPD2BIN[dpd]*4]; \ if (c!=cstart) {memcpy(c, u+1, 4); c+=3;} \ else if (*u) {memcpy(c, u+4-*u, 4); c+=*u;} dpd=(sourhi>>8)&0x3ff; /* declet 1 */ dpd2char; dpd=((sourhi&0xff)<<2) | (sourlo>>30); /* declet 2 */ dpd2char; dpd=(sourlo>>20)&0x3ff; /* declet 3 */ dpd2char; dpd=(sourlo>>10)&0x3ff; /* declet 4 */ dpd2char; dpd=(sourlo)&0x3ff; /* declet 5 */ dpd2char; if (c==cstart) *c++='0'; /* all zeros -- make 0 */ if (exp==0) { /* integer or NaN case -- easy */ *c='\0'; /* terminate */ return string; } /* non-0 exponent */ e=0; /* assume no E */ pre=c-cstart+exp; /* [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 */ s=c-1; /* source (LSD) */ if (pre>0) { /* ddd.ddd (plain), perhaps with E */ char *dotat=cstart+pre; if (dotat<c) { /* if embedded dot needed... */ t=c; /* target */ for (; s>=dotat; s--, t--) *t=*s; /* open the gap; leave t at gap */ *t='.'; /* insert the dot */ c++; /* length increased by one */ } /* finally add the E-part, if needed; it will never be 0, and has */ /* a maximum length of 3 digits */ if (e!=0) { *c++='E'; /* starts with E */ *c++='+'; /* assume positive */ if (e<0) { *(c-1)='-'; /* oops, need '-' */ e=-e; /* uInt, please */ } u=&BIN2CHAR[e*4]; /* -> length byte */ memcpy(c, u+4-*u, 4); /* copy fixed 4 characters [is safe] */ c+=*u; /* bump pointer appropriately */ } *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) */ t=c+1-pre; *(t+1)='\0'; /* can add terminator now */ for (; s>=cstart; s--, t--) *t=*s; /* shift whole coefficient right */ c=cstart; *c++='0'; /* always starts with 0. */ *c++='.'; for (; pre<0; pre++) *c++='0'; /* add any 0's after '.' */ /*printf("res %s\n", string); */ return string; } /* decimal64ToString */ /* ------------------------------------------------------------------ */ /* to-number -- conversion from numeric string */ /* */ /* decimal64FromString(result, string, set); */ /* */ /* result is the decimal64 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) */ /* set is the context */ /* */ /* The context is supplied to this routine is used for error handling */ /* (setting of status and traps) and for the rounding mode, only. */ /* If an error occurs, the result will be a valid decimal64 NaN. */ /* ------------------------------------------------------------------ */ decimal64 * decimal64FromString(decimal64 *result, const char *string, decContext *set) { decContext dc; /* work */ decNumber dn; /* .. */ decContextDefault(&dc, DEC_INIT_DECIMAL64); /* no traps, please */ dc.round=set->round; /* use supplied rounding */ decNumberFromString(&dn, string, &dc); /* will round if needed */ decimal64FromNumber(result, &dn, &dc); if (dc.status!=0) { /* something happened */ decContextSetStatus(set, dc.status); /* .. pass it on */ } return result; } /* decimal64FromString */ /* ------------------------------------------------------------------ */ /* decimal64IsCanonical -- test whether encoding is canonical */ /* d64 is the source decimal64 */ /* returns 1 if the encoding of d64 is canonical, 0 otherwise */ /* No error is possible. */ /* ------------------------------------------------------------------ */ uInt decimal64IsCanonical(const decimal64 *d64) { decNumber dn; /* work */ decimal64 canon; /* .. */ decContext dc; /* .. */ decContextDefault(&dc, DEC_INIT_DECIMAL64); decimal64ToNumber(d64, &dn); decimal64FromNumber(&canon, &dn, &dc);/* canon will now be canonical */ return memcmp(d64, &canon, DECIMAL64_Bytes)==0; } /* decimal64IsCanonical */ /* ------------------------------------------------------------------ */ /* decimal64Canonical -- copy an encoding, ensuring it is canonical */ /* d64 is the source decimal64 */ /* result is the target (may be the same decimal64) */ /* returns result */ /* No error is possible. */ /* ------------------------------------------------------------------ */ decimal64 * decimal64Canonical(decimal64 *result, const decimal64 *d64) { decNumber dn; /* work */ decContext dc; /* .. */ decContextDefault(&dc, DEC_INIT_DECIMAL64); decimal64ToNumber(d64, &dn); decimal64FromNumber(result, &dn, &dc);/* result will now be canonical */ return result; } /* decimal64Canonical */ #if DECTRACE || DECCHECK /* Macros for accessing decimal64 fields. These assume the argument is a reference (pointer) to the decimal64 structure, and the decimal64 is in network byte order (big-endian) */ /* Get sign */ #define decimal64Sign(d) ((unsigned)(d)->bytes[0]>>7) /* Get combination field */ #define decimal64Comb(d) (((d)->bytes[0] & 0x7c)>>2) /* Get exponent continuation [does not remove bias] */ #define decimal64ExpCon(d) ((((d)->bytes[0] & 0x03)<<6) \ | ((unsigned)(d)->bytes[1]>>2)) /* Set sign [this assumes sign previously 0] */ #define decimal64SetSign(d, b) { \ (d)->bytes[0]|=((unsigned)(b)<<7);} /* Set exponent continuation [does not apply bias] */ /* This assumes range has been checked and exponent previously 0; */ /* type of exponent must be unsigned */ #define decimal64SetExpCon(d, e) { \ (d)->bytes[0]|=(uByte)((e)>>6); \ (d)->bytes[1]|=(uByte)(((e)&0x3F)<<2);} /* ------------------------------------------------------------------ */ /* decimal64Show -- display a decimal64 in hexadecimal [debug aid] */ /* d64 -- the number to show */ /* ------------------------------------------------------------------ */ /* Also shows sign/cob/expconfields extracted */ void decimal64Show(const decimal64 *d64) { char buf[DECIMAL64_Bytes*2+1]; Int i, j=0; if (DECLITEND) { for (i=0; i<DECIMAL64_Bytes; i++, j+=2) { sprintf(&buf[j], "%02x", d64->bytes[7-i]); } printf(" D64> %s [S:%d Cb:%02x Ec:%02x] LittleEndian\n", buf, d64->bytes[7]>>7, (d64->bytes[7]>>2)&0x1f, ((d64->bytes[7]&0x3)<<6)| (d64->bytes[6]>>2)); } else { /* big-endian */ for (i=0; i<DECIMAL64_Bytes; i++, j+=2) { sprintf(&buf[j], "%02x", d64->bytes[i]); } printf(" D64> %s [S:%d Cb:%02x Ec:%02x] BigEndian\n", buf, decimal64Sign(d64), decimal64Comb(d64), decimal64ExpCon(d64)); } } /* decimal64Show */ #endif /* ================================================================== */ /* Shared utility routines and tables */ /* ================================================================== */ /* define and include the conversion tables to use for shared code */ #if DECDPUN==3 #define DEC_DPD2BIN 1 #else #define DEC_DPD2BCD 1 #endif #include "decDPD.h" /* lookup tables */ /* The maximum number of decNumberUnits needed for a working copy of */ /* the units array is the ceiling of digits/DECDPUN, where digits is */ /* the maximum number of digits in any of the formats for which this */ /* is used. decimal128.h must not be included in this module, so, as */ /* a very special case, that number is defined as a literal here. */ #define DECMAX754 34 #define DECMAXUNITS ((DECMAX754+DECDPUN-1)/DECDPUN) /* ------------------------------------------------------------------ */ /* Combination field lookup tables (uInts to save measurable work) */ /* */ /* COMBEXP - 2-bit most-significant-bits of exponent */ /* [11 if an Infinity or NaN] */ /* COMBMSD - 4-bit most-significant-digit */ /* [0=Infinity, 1=NaN if COMBEXP=11] */ /* */ /* Both are indexed by the 5-bit combination field (0-31) */ /* ------------------------------------------------------------------ */ const uInt COMBEXP[32]={0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 0, 0, 1, 1, 2, 2, 3, 3}; const uInt COMBMSD[32]={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, 1}; /* ------------------------------------------------------------------ */ /* decDigitsToDPD -- pack coefficient into DPD form */ /* */ /* dn is the source number (assumed valid, max DECMAX754 digits) */ /* targ is 1, 2, or 4-element uInt array, which the caller must */ /* have cleared to zeros */ /* shift is the number of 0 digits to add on the right (normally 0) */ /* */ /* The coefficient must be known small enough to fit. The full */ /* coefficient is copied, including the leading 'odd' digit. This */ /* digit is retrieved and packed into the combination field by the */ /* caller. */ /* */ /* The target uInts are altered only as necessary to receive the */ /* digits of the decNumber. When more than one uInt is needed, they */ /* are filled from left to right (that is, the uInt at offset 0 will */ /* end up with the least-significant digits). */ /* */ /* shift is used for 'fold-down' padding. */ /* */ /* No error is possible. */ /* ------------------------------------------------------------------ */ #if DECDPUN<=4 /* Constant multipliers for divide-by-power-of five using reciprocal */ /* multiply, after removing powers of 2 by shifting, and final shift */ /* of 17 [we only need up to **4] */ static const uInt multies[]={131073, 26215, 5243, 1049, 210}; /* QUOT10 -- macro to return the quotient of unit u divided by 10**n */ #define QUOT10(u, n) ((((uInt)(u)>>(n))*multies[n])>>17) #endif void decDigitsToDPD(const decNumber *dn, uInt *targ, Int shift) { Int cut; /* work */ Int n; /* output bunch counter */ Int digits=dn->digits; /* digit countdown */ uInt dpd; /* densely packed decimal value */ uInt bin; /* binary value 0-999 */ uInt *uout=targ; /* -> current output uInt */ uInt uoff=0; /* -> current output offset [from right] */ const Unit *inu=dn->lsu; /* -> current input unit */ Unit uar[DECMAXUNITS]; /* working copy of units, iff shifted */ #if DECDPUN!=3 /* not fast path */ Unit in; /* current unit */ #endif if (shift!=0) { /* shift towards most significant required */ /* shift the units array to the left by pad digits and copy */ /* [this code is a special case of decShiftToMost, which could */ /* be used instead if exposed and the array were copied first] */ const Unit *source; /* .. */ Unit *target, *first; /* .. */ uInt next=0; /* work */ source=dn->lsu+D2U(digits)-1; /* where msu comes from */ target=uar+D2U(digits)-1+D2U(shift);/* where upper part of first cut goes */ cut=DECDPUN-MSUDIGITS(shift); /* where to slice */ if (cut==0) { /* unit-boundary case */ for (; source>=dn->lsu; source--, target--) *target=*source; } else { first=uar+D2U(digits+shift)-1; /* where msu will end up */ for (; source>=dn->lsu; source--, target--) { /* split the source Unit and accumulate remainder for next */ #if DECDPUN<=4 uInt quot=QUOT10(*source, cut); uInt rem=*source-quot*DECPOWERS[cut]; next+=quot; #else uInt rem=*source%DECPOWERS[cut]; next+=*source/DECPOWERS[cut]; #endif if (target<=first) *target=(Unit)next; /* write to target iff valid */ next=rem*DECPOWERS[DECDPUN-cut]; /* save remainder for next Unit */ } } /* shift-move */ /* propagate remainder to one below and clear the rest */ for (; target>=uar; target--) { *target=(Unit)next; next=0; } digits+=shift; /* add count (shift) of zeros added */ inu=uar; /* use units in working array */ } /* now densely pack the coefficient into DPD declets */ #if DECDPUN!=3 /* not fast path */ in=*inu; /* current unit */ cut=0; /* at lowest digit */ bin=0; /* [keep compiler quiet] */ #endif for(n=0; digits>0; n++) { /* each output bunch */ #if DECDPUN==3 /* fast path, 3-at-a-time */ bin=*inu; /* 3 digits ready for convert */ digits-=3; /* [may go negative] */ inu++; /* may need another */ #else /* must collect digit-by-digit */ Unit dig; /* current digit */ Int j; /* digit-in-declet count */ for (j=0; j<3; j++) { #if DECDPUN<=4 Unit temp=(Unit)((uInt)(in*6554)>>16); dig=(Unit)(in-X10(temp)); in=temp; #else dig=in%10; in=in/10; #endif if (j==0) bin=dig; else if (j==1) bin+=X10(dig); else /* j==2 */ bin+=X100(dig); digits--; if (digits==0) break; /* [also protects *inu below] */ cut++; if (cut==DECDPUN) {inu++; in=*inu; cut=0;} } #endif /* here there are 3 digits in bin, or have used all input digits */ dpd=BIN2DPD[bin]; /* write declet to uInt array */ *uout|=dpd<<uoff; uoff+=10; if (uoff<32) continue; /* no uInt boundary cross */ uout++; uoff-=32; *uout|=dpd>>(10-uoff); /* collect top bits */ } /* n declets */ return; } /* decDigitsToDPD */ /* ------------------------------------------------------------------ */ /* decDigitsFromDPD -- unpack a format's coefficient */ /* */ /* dn is the target number, with 7, 16, or 34-digit space. */ /* sour is a 1, 2, or 4-element uInt array containing only declets */ /* declets is the number of (right-aligned) declets in sour to */ /* be processed. This may be 1 more than the obvious number in */ /* a format, as any top digit is prefixed to the coefficient */ /* continuation field. It also may be as small as 1, as the */ /* caller may pre-process leading zero declets. */ /* */ /* When doing the 'extra declet' case care is taken to avoid writing */ /* extra digits when there are leading zeros, as these could overflow */ /* the units array when DECDPUN is not 3. */ /* */ /* The target uInts are used only as necessary to process declets */ /* declets into the decNumber. When more than one uInt is needed, */ /* they are used from left to right (that is, the uInt at offset 0 */ /* provides the least-significant digits). */ /* */ /* dn->digits is set, but not the sign or exponent. */ /* No error is possible [the redundant 888 codes are allowed]. */ /* ------------------------------------------------------------------ */ void decDigitsFromDPD(decNumber *dn, const uInt *sour, Int declets) { uInt dpd; /* collector for 10 bits */ Int n; /* counter */ Unit *uout=dn->lsu; /* -> current output unit */ Unit *last=uout; /* will be unit containing msd */ const uInt *uin=sour; /* -> current input uInt */ uInt uoff=0; /* -> current input offset [from right] */ #if DECDPUN!=3 uInt bcd; /* BCD result */ uInt nibble; /* work */ Unit out=0; /* accumulator */ Int cut=0; /* power of ten in current unit */ #endif #if DECDPUN>4 uInt const *pow; /* work */ #endif /* Expand the densely-packed integer, right to left */ for (n=declets-1; n>=0; n--) { /* count down declets of 10 bits */ dpd=*uin>>uoff; uoff+=10; if (uoff>32) { /* crossed uInt boundary */ uin++; uoff-=32; dpd|=*uin<<(10-uoff); /* get waiting bits */ } dpd&=0x3ff; /* clear uninteresting bits */ #if DECDPUN==3 if (dpd==0) *uout=0; else { *uout=DPD2BIN[dpd]; /* convert 10 bits to binary 0-999 */ last=uout; /* record most significant unit */ } uout++; } /* n */ #else /* DECDPUN!=3 */ if (dpd==0) { /* fastpath [e.g., leading zeros] */ /* write out three 0 digits (nibbles); out may have digit(s) */ cut++; if (cut==DECDPUN) {*uout=out; if (out) {last=uout; out=0;} uout++; cut=0;} if (n==0) break; /* [as below, works even if MSD=0] */ cut++; if (cut==DECDPUN) {*uout=out; if (out) {last=uout; out=0;} uout++; cut=0;} cut++; if (cut==DECDPUN) {*uout=out; if (out) {last=uout; out=0;} uout++; cut=0;} continue; } bcd=DPD2BCD[dpd]; /* convert 10 bits to 12 bits BCD */ /* now accumulate the 3 BCD nibbles into units */ nibble=bcd & 0x00f; if (nibble) out=(Unit)(out+nibble*DECPOWERS[cut]); cut++; if (cut==DECDPUN) {*uout=out; if (out) {last=uout; out=0;} uout++; cut=0;} bcd>>=4; /* if this is the last declet and the remaining nibbles in bcd */ /* are 00 then process no more nibbles, because this could be */ /* the 'odd' MSD declet and writing any more Units would then */ /* overflow the unit array */ if (n==0 && !bcd) break; nibble=bcd & 0x00f; if (nibble) out=(Unit)(out+nibble*DECPOWERS[cut]); cut++; if (cut==DECDPUN) {*uout=out; if (out) {last=uout; out=0;} uout++; cut=0;} bcd>>=4; nibble=bcd & 0x00f; if (nibble) out=(Unit)(out+nibble*DECPOWERS[cut]); cut++; if (cut==DECDPUN) {*uout=out; if (out) {last=uout; out=0;} uout++; cut=0;} } /* n */ if (cut!=0) { /* some more left over */ *uout=out; /* write out final unit */ if (out) last=uout; /* and note if non-zero */ } #endif /* here, last points to the most significant unit with digits; */ /* inspect it to get the final digits count -- this is essentially */ /* the same code as decGetDigits in decNumber.c */ dn->digits=(last-dn->lsu)*DECDPUN+1; /* floor of digits, plus */ /* must be at least 1 digit */ #if DECDPUN>1 if (*last<10) return; /* common odd digit or 0 */ dn->digits++; /* must be 2 at least */ #if DECDPUN>2 if (*last<100) return; /* 10-99 */ dn->digits++; /* must be 3 at least */ #if DECDPUN>3 if (*last<1000) return; /* 100-999 */ dn->digits++; /* must be 4 at least */ #if DECDPUN>4 for (pow=&DECPOWERS[4]; *last>=*pow; pow++) dn->digits++; #endif #endif #endif #endif return; } /*decDigitsFromDPD */