| /* Decimal 64-bit format module for the decNumber C Library. |
| Copyright (C) 2005, 2007 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 2, or (at your option) any later |
| version. |
| |
| In addition to the permissions in the GNU General Public License, |
| the Free Software Foundation gives you unlimited permission to link |
| the compiled version of this file into combinations with other |
| programs, and to distribute those combinations without any |
| restriction coming from the use of this file. (The General Public |
| License restrictions do apply in other respects; for example, they |
| cover modification of the file, and distribution when not linked |
| into a combine executable.) |
| |
| 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. |
| |
| You should have received a copy of the GNU General Public License |
| along with GCC; see the file COPYING. If not, write to the Free |
| Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301, USA. */ |
| |
| /* ------------------------------------------------------------------ */ |
| /* 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 "qemu/osdep.h" |
| |
| #include "libdecnumber/dconfig.h" |
| #define DECNUMDIGITS 16 /* make decNumbers with space for 16 */ |
| #include "libdecnumber/decNumber.h" |
| #include "libdecnumber/decNumberLocal.h" |
| #include "libdecnumber/dpd/decimal64.h" |
| |
| /* Utility routines and tables [in decimal64.c]; externs for C++ */ |
| extern const uInt COMBEXP[32], COMBMSD[32]; |
| 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 "libdecnumber/decDPD.h" |
| |
| /* ------------------------------------------------------------------ */ |
| /* 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 *pu; /* .. */ |
| uInt comb, exp; /* .. */ |
| 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 */ |
| pu=(uInt *)d64->bytes; /* overlay */ |
| if (DECLITEND) { |
| pu[0]=targar[0]; /* directly store the low int */ |
| pu[1]=targar[1]; /* then the high int */ |
| } |
| else { |
| pu[0]=targar[1]; /* directly store the high int */ |
| pu[1]=targar[0]; /* then the low int */ |
| } |
| |
| 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 */ |
| const uInt *pu; /* work */ |
| Int need; /* .. */ |
| 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 */ |
| pu=(const uInt *)d64->bytes; /* overlay */ |
| if (DECLITEND) { |
| sourlo=pu[0]; /* directly load the low int */ |
| sourhi=pu[1]; /* then the high int */ |
| } |
| else { |
| sourhi=pu[0]; /* directly load the high int */ |
| sourlo=pu[1]; /* 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 uInt *pu; /* work */ |
| char *s, *t; /* .. (source, target) */ |
| Int dpd; /* .. */ |
| Int pre, e; /* .. */ |
| const uByte *u; /* .. */ |
| |
| 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 */ |
| pu=(const uInt *)d64->bytes; /* overlay */ |
| if (DECLITEND) { |
| sourlo=pu[0]; /* directly load the low int */ |
| sourhi=pu[1]; /* then the high int */ |
| } |
| else { |
| sourhi=pu[0]; /* directly load the high int */ |
| sourlo=pu[1]; /* 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. */ |
| /* ------------------------------------------------------------------ */ |
| uint32_t 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]|=(uint8_t)((e)>>6); \ |
| (d)->bytes[1]|=(uint8_t)(((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 "libdecnumber/decDPD.h" |
| |
| /* 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 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 |
| |
| while (digits > 0) { /* 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 */ |
