cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
Log | Files | Refs | Submodules | LICENSE | sfeed.txt

decimal64.c (32951B)


      1/* Decimal 64-bit format module for the decNumber C Library.
      2   Copyright (C) 2005, 2007 Free Software Foundation, Inc.
      3   Contributed by IBM Corporation.  Author Mike Cowlishaw.
      4
      5   This file is part of GCC.
      6
      7   GCC is free software; you can redistribute it and/or modify it under
      8   the terms of the GNU General Public License as published by the Free
      9   Software Foundation; either version 2, or (at your option) any later
     10   version.
     11
     12   In addition to the permissions in the GNU General Public License,
     13   the Free Software Foundation gives you unlimited permission to link
     14   the compiled version of this file into combinations with other
     15   programs, and to distribute those combinations without any
     16   restriction coming from the use of this file.  (The General Public
     17   License restrictions do apply in other respects; for example, they
     18   cover modification of the file, and distribution when not linked
     19   into a combine executable.)
     20
     21   GCC is distributed in the hope that it will be useful, but WITHOUT ANY
     22   WARRANTY; without even the implied warranty of MERCHANTABILITY or
     23   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
     24   for more details.
     25
     26   You should have received a copy of the GNU General Public License
     27   along with GCC; see the file COPYING.  If not, write to the Free
     28   Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
     29   02110-1301, USA.  */
     30
     31/* ------------------------------------------------------------------ */
     32/* Decimal 64-bit format module					      */
     33/* ------------------------------------------------------------------ */
     34/* This module comprises the routines for decimal64 format numbers.   */
     35/* Conversions are supplied to and from decNumber and String.	      */
     36/*								      */
     37/* This is used when decNumber provides operations, either for all    */
     38/* operations or as a proxy between decNumber and decSingle.	      */
     39/*								      */
     40/* Error handling is the same as decNumber (qv.).		      */
     41/* ------------------------------------------------------------------ */
     42#include "qemu/osdep.h"
     43
     44#include "libdecnumber/dconfig.h"
     45#define	 DECNUMDIGITS 16      /* make decNumbers with space for 16 */
     46#include "libdecnumber/decNumber.h"
     47#include "libdecnumber/decNumberLocal.h"
     48#include "libdecnumber/dpd/decimal64.h"
     49
     50/* Utility routines and tables [in decimal64.c]; externs for C++ */
     51extern const uInt COMBEXP[32], COMBMSD[32];
     52extern const uByte  BIN2CHAR[4001];
     53
     54extern void decDigitsFromDPD(decNumber *, const uInt *, Int);
     55extern void decDigitsToDPD(const decNumber *, uInt *, Int);
     56
     57#if DECTRACE || DECCHECK
     58void decimal64Show(const decimal64 *);		  /* for debug */
     59extern void decNumberShow(const decNumber *);	  /* .. */
     60#endif
     61
     62/* Useful macro */
     63/* Clear a structure (e.g., a decNumber) */
     64#define DEC_clear(d) memset(d, 0, sizeof(*d))
     65
     66/* define and include the tables to use for conversions */
     67#define DEC_BIN2CHAR 1
     68#define DEC_DPD2BIN  1
     69#define DEC_BIN2DPD  1		   /* used for all sizes */
     70#include "libdecnumber/decDPD.h"
     71
     72/* ------------------------------------------------------------------ */
     73/* decimal64FromNumber -- convert decNumber to decimal64	      */
     74/*								      */
     75/*   ds is the target decimal64					      */
     76/*   dn is the source number (assumed valid)			      */
     77/*   set is the context, used only for reporting errors		      */
     78/*								      */
     79/* The set argument is used only for status reporting and for the     */
     80/* rounding mode (used if the coefficient is more than DECIMAL64_Pmax */
     81/* digits or an overflow is detected).	If the exponent is out of the */
     82/* valid range then Overflow or Underflow will be raised.	      */
     83/* After Underflow a subnormal result is possible.		      */
     84/*								      */
     85/* DEC_Clamped is set if the number has to be 'folded down' to fit,   */
     86/* by reducing its exponent and multiplying the coefficient by a      */
     87/* power of ten, or if the exponent on a zero had to be clamped.      */
     88/* ------------------------------------------------------------------ */
     89decimal64 * decimal64FromNumber(decimal64 *d64, const decNumber *dn,
     90				decContext *set) {
     91  uInt status=0;		   /* status accumulator */
     92  Int ae;			   /* adjusted exponent */
     93  decNumber  dw;		   /* work */
     94  decContext dc;		   /* .. */
     95  uInt *pu;			   /* .. */
     96  uInt comb, exp;		   /* .. */
     97  uInt targar[2]={0, 0};	   /* target 64-bit */
     98  #define targhi targar[1]	   /* name the word with the sign */
     99  #define targlo targar[0]	   /* and the other */
    100
    101  /* If the number has too many digits, or the exponent could be */
    102  /* out of range then reduce the number under the appropriate */
    103  /* constraints.  This could push the number to Infinity or zero, */
    104  /* so this check and rounding must be done before generating the */
    105  /* decimal64] */
    106  ae=dn->exponent+dn->digits-1;		     /* [0 if special] */
    107  if (dn->digits>DECIMAL64_Pmax		     /* too many digits */
    108   || ae>DECIMAL64_Emax			     /* likely overflow */
    109   || ae<DECIMAL64_Emin) {		     /* likely underflow */
    110    decContextDefault(&dc, DEC_INIT_DECIMAL64); /* [no traps] */
    111    dc.round=set->round;		     /* use supplied rounding */
    112    decNumberPlus(&dw, dn, &dc);	     /* (round and check) */
    113    /* [this changes -0 to 0, so enforce the sign...] */
    114    dw.bits|=dn->bits&DECNEG;
    115    status=dc.status;			     /* save status */
    116    dn=&dw;				     /* use the work number */
    117    } /* maybe out of range */
    118
    119  if (dn->bits&DECSPECIAL) {			  /* a special value */
    120    if (dn->bits&DECINF) targhi=DECIMAL_Inf<<24;
    121     else {					  /* sNaN or qNaN */
    122      if ((*dn->lsu!=0 || dn->digits>1)		  /* non-zero coefficient */
    123       && (dn->digits<DECIMAL64_Pmax)) {	  /* coefficient fits */
    124	decDigitsToDPD(dn, targar, 0);
    125	}
    126      if (dn->bits&DECNAN) targhi|=DECIMAL_NaN<<24;
    127       else targhi|=DECIMAL_sNaN<<24;
    128      } /* a NaN */
    129    } /* special */
    130
    131   else { /* is finite */
    132    if (decNumberIsZero(dn)) {		     /* is a zero */
    133      /* set and clamp exponent */
    134      if (dn->exponent<-DECIMAL64_Bias) {
    135	exp=0;				     /* low clamp */
    136	status|=DEC_Clamped;
    137	}
    138       else {
    139	exp=dn->exponent+DECIMAL64_Bias;     /* bias exponent */
    140	if (exp>DECIMAL64_Ehigh) {	     /* top clamp */
    141	  exp=DECIMAL64_Ehigh;
    142	  status|=DEC_Clamped;
    143	  }
    144	}
    145      comb=(exp>>5) & 0x18;		/* msd=0, exp top 2 bits .. */
    146      }
    147     else {				/* non-zero finite number */
    148      uInt msd;				/* work */
    149      Int pad=0;			/* coefficient pad digits */
    150
    151      /* the dn is known to fit, but it may need to be padded */
    152      exp=(uInt)(dn->exponent+DECIMAL64_Bias);	  /* bias exponent */
    153      if (exp>DECIMAL64_Ehigh) {		  /* fold-down case */
    154	pad=exp-DECIMAL64_Ehigh;
    155	exp=DECIMAL64_Ehigh;			  /* [to maximum] */
    156	status|=DEC_Clamped;
    157	}
    158
    159      /* fastpath common case */
    160      if (DECDPUN==3 && pad==0) {
    161	uInt dpd[6]={0,0,0,0,0,0};
    162	uInt i;
    163	Int d=dn->digits;
    164	for (i=0; d>0; i++, d-=3) dpd[i]=BIN2DPD[dn->lsu[i]];
    165	targlo =dpd[0];
    166	targlo|=dpd[1]<<10;
    167	targlo|=dpd[2]<<20;
    168	if (dn->digits>6) {
    169	  targlo|=dpd[3]<<30;
    170	  targhi =dpd[3]>>2;
    171	  targhi|=dpd[4]<<8;
    172	  }
    173	msd=dpd[5];		   /* [did not really need conversion] */
    174	}
    175       else { /* general case */
    176	decDigitsToDPD(dn, targar, pad);
    177	/* save and clear the top digit */
    178	msd=targhi>>18;
    179	targhi&=0x0003ffff;
    180	}
    181
    182      /* create the combination field */
    183      if (msd>=8) comb=0x18 | ((exp>>7) & 0x06) | (msd & 0x01);
    184	     else comb=((exp>>5) & 0x18) | msd;
    185      }
    186    targhi|=comb<<26;		   /* add combination field .. */
    187    targhi|=(exp&0xff)<<18;	   /* .. and exponent continuation */
    188    } /* finite */
    189
    190  if (dn->bits&DECNEG) targhi|=0x80000000; /* add sign bit */
    191
    192  /* now write to storage; this is now always endian */
    193  pu=(uInt *)d64->bytes;	   /* overlay */
    194  if (DECLITEND) {
    195    pu[0]=targar[0];		   /* directly store the low int */
    196    pu[1]=targar[1];		   /* then the high int */
    197    }
    198   else {
    199    pu[0]=targar[1];		   /* directly store the high int */
    200    pu[1]=targar[0];		   /* then the low int */
    201    }
    202
    203  if (status!=0) decContextSetStatus(set, status); /* pass on status */
    204  /* decimal64Show(d64); */
    205  return d64;
    206  } /* decimal64FromNumber */
    207
    208/* ------------------------------------------------------------------ */
    209/* decimal64ToNumber -- convert decimal64 to decNumber		      */
    210/*   d64 is the source decimal64				      */
    211/*   dn is the target number, with appropriate space		      */
    212/* No error is possible.					      */
    213/* ------------------------------------------------------------------ */
    214decNumber * decimal64ToNumber(const decimal64 *d64, decNumber *dn) {
    215  uInt msd;			   /* coefficient MSD */
    216  uInt exp;			   /* exponent top two bits */
    217  uInt comb;			   /* combination field */
    218  const uInt *pu;		   /* work */
    219  Int  need;			   /* .. */
    220  uInt sourar[2];		   /* source 64-bit */
    221  #define sourhi sourar[1]	   /* name the word with the sign */
    222  #define sourlo sourar[0]	   /* and the lower word */
    223
    224  /* load source from storage; this is endian */
    225  pu=(const uInt *)d64->bytes;	   /* overlay */
    226  if (DECLITEND) {
    227    sourlo=pu[0];		   /* directly load the low int */
    228    sourhi=pu[1];		   /* then the high int */
    229    }
    230   else {
    231    sourhi=pu[0];		   /* directly load the high int */
    232    sourlo=pu[1];		   /* then the low int */
    233    }
    234
    235  comb=(sourhi>>26)&0x1f;	   /* combination field */
    236
    237  decNumberZero(dn);		   /* clean number */
    238  if (sourhi&0x80000000) dn->bits=DECNEG; /* set sign if negative */
    239
    240  msd=COMBMSD[comb];		   /* decode the combination field */
    241  exp=COMBEXP[comb];		   /* .. */
    242
    243  if (exp==3) {			   /* is a special */
    244    if (msd==0) {
    245      dn->bits|=DECINF;
    246      return dn;		   /* no coefficient needed */
    247      }
    248    else if (sourhi&0x02000000) dn->bits|=DECSNAN;
    249    else dn->bits|=DECNAN;
    250    msd=0;			   /* no top digit */
    251    }
    252   else {			   /* is a finite number */
    253    dn->exponent=(exp<<8)+((sourhi>>18)&0xff)-DECIMAL64_Bias; /* unbiased */
    254    }
    255
    256  /* get the coefficient */
    257  sourhi&=0x0003ffff;		   /* clean coefficient continuation */
    258  if (msd) {			   /* non-zero msd */
    259    sourhi|=msd<<18;		   /* prefix to coefficient */
    260    need=6;			   /* process 6 declets */
    261    }
    262   else { /* msd=0 */
    263    if (!sourhi) {		   /* top word 0 */
    264      if (!sourlo) return dn;	   /* easy: coefficient is 0 */
    265      need=3;			   /* process at least 3 declets */
    266      if (sourlo&0xc0000000) need++; /* process 4 declets */
    267      /* [could reduce some more, here] */
    268      }
    269     else {			   /* some bits in top word, msd=0 */
    270      need=4;			   /* process at least 4 declets */
    271      if (sourhi&0x0003ff00) need++; /* top declet!=0, process 5 */
    272      }
    273    } /*msd=0 */
    274
    275  decDigitsFromDPD(dn, sourar, need);	/* process declets */
    276  return dn;
    277  } /* decimal64ToNumber */
    278
    279
    280/* ------------------------------------------------------------------ */
    281/* to-scientific-string -- conversion to numeric string		      */
    282/* to-engineering-string -- conversion to numeric string	      */
    283/*								      */
    284/*   decimal64ToString(d64, string);				      */
    285/*   decimal64ToEngString(d64, string);				      */
    286/*								      */
    287/*  d64 is the decimal64 format number to convert		      */
    288/*  string is the string where the result will be laid out	      */
    289/*								      */
    290/*  string must be at least 24 characters			      */
    291/*								      */
    292/*  No error is possible, and no status can be set.		      */
    293/* ------------------------------------------------------------------ */
    294char * decimal64ToEngString(const decimal64 *d64, char *string){
    295  decNumber dn;				/* work */
    296  decimal64ToNumber(d64, &dn);
    297  decNumberToEngString(&dn, string);
    298  return string;
    299  } /* decimal64ToEngString */
    300
    301char * decimal64ToString(const decimal64 *d64, char *string){
    302  uInt msd;			   /* coefficient MSD */
    303  Int  exp;			   /* exponent top two bits or full */
    304  uInt comb;			   /* combination field */
    305  char *cstart;			   /* coefficient start */
    306  char *c;			   /* output pointer in string */
    307  const uInt *pu;		   /* work */
    308  char *s, *t;			   /* .. (source, target) */
    309  Int  dpd;			   /* .. */
    310  Int  pre, e;			   /* .. */
    311  const uByte *u;		   /* .. */
    312
    313  uInt sourar[2];		   /* source 64-bit */
    314  #define sourhi sourar[1]	   /* name the word with the sign */
    315  #define sourlo sourar[0]	   /* and the lower word */
    316
    317  /* load source from storage; this is endian */
    318  pu=(const uInt *)d64->bytes;	   /* overlay */
    319  if (DECLITEND) {
    320    sourlo=pu[0];		   /* directly load the low int */
    321    sourhi=pu[1];		   /* then the high int */
    322    }
    323   else {
    324    sourhi=pu[0];		   /* directly load the high int */
    325    sourlo=pu[1];		   /* then the low int */
    326    }
    327
    328  c=string;			   /* where result will go */
    329  if (((Int)sourhi)<0) *c++='-';   /* handle sign */
    330
    331  comb=(sourhi>>26)&0x1f;	   /* combination field */
    332  msd=COMBMSD[comb];		   /* decode the combination field */
    333  exp=COMBEXP[comb];		   /* .. */
    334
    335  if (exp==3) {
    336    if (msd==0) {		   /* infinity */
    337      strcpy(c,	  "Inf");
    338      strcpy(c+3, "inity");
    339      return string;		   /* easy */
    340      }
    341    if (sourhi&0x02000000) *c++='s'; /* sNaN */
    342    strcpy(c, "NaN");		   /* complete word */
    343    c+=3;			   /* step past */
    344    if (sourlo==0 && (sourhi&0x0003ffff)==0) return string; /* zero payload */
    345    /* otherwise drop through to add integer; set correct exp */
    346    exp=0; msd=0;		   /* setup for following code */
    347    }
    348   else exp=(exp<<8)+((sourhi>>18)&0xff)-DECIMAL64_Bias;
    349
    350  /* convert 16 digits of significand to characters */
    351  cstart=c;			   /* save start of coefficient */
    352  if (msd) *c++='0'+(char)msd;	   /* non-zero most significant digit */
    353
    354  /* Now decode the declets.  After extracting each one, it is */
    355  /* decoded to binary and then to a 4-char sequence by table lookup; */
    356  /* the 4-chars are a 1-char length (significant digits, except 000 */
    357  /* has length 0).  This allows us to left-align the first declet */
    358  /* with non-zero content, then remaining ones are full 3-char */
    359  /* length.  We use fixed-length memcpys because variable-length */
    360  /* causes a subroutine call in GCC.  (These are length 4 for speed */
    361  /* and are safe because the array has an extra terminator byte.) */
    362  #define dpd2char u=&BIN2CHAR[DPD2BIN[dpd]*4];			  \
    363		   if (c!=cstart) {memcpy(c, u+1, 4); c+=3;}	  \
    364		    else if (*u)  {memcpy(c, u+4-*u, 4); c+=*u;}
    365
    366  dpd=(sourhi>>8)&0x3ff;		     /* declet 1 */
    367  dpd2char;
    368  dpd=((sourhi&0xff)<<2) | (sourlo>>30);     /* declet 2 */
    369  dpd2char;
    370  dpd=(sourlo>>20)&0x3ff;		     /* declet 3 */
    371  dpd2char;
    372  dpd=(sourlo>>10)&0x3ff;		     /* declet 4 */
    373  dpd2char;
    374  dpd=(sourlo)&0x3ff;			     /* declet 5 */
    375  dpd2char;
    376
    377  if (c==cstart) *c++='0';	   /* all zeros -- make 0 */
    378
    379  if (exp==0) {			   /* integer or NaN case -- easy */
    380    *c='\0';			   /* terminate */
    381    return string;
    382    }
    383
    384  /* non-0 exponent */
    385  e=0;				   /* assume no E */
    386  pre=c-cstart+exp;
    387  /* [here, pre-exp is the digits count (==1 for zero)] */
    388  if (exp>0 || pre<-5) {	   /* need exponential form */
    389    e=pre-1;			   /* calculate E value */
    390    pre=1;			   /* assume one digit before '.' */
    391    } /* exponential form */
    392
    393  /* modify the coefficient, adding 0s, '.', and E+nn as needed */
    394  s=c-1;			   /* source (LSD) */
    395  if (pre>0) {			   /* ddd.ddd (plain), perhaps with E */
    396    char *dotat=cstart+pre;
    397    if (dotat<c) {		   /* if embedded dot needed... */
    398      t=c;				/* target */
    399      for (; s>=dotat; s--, t--) *t=*s; /* open the gap; leave t at gap */
    400      *t='.';				/* insert the dot */
    401      c++;				/* length increased by one */
    402      }
    403
    404    /* finally add the E-part, if needed; it will never be 0, and has */
    405    /* a maximum length of 3 digits */
    406    if (e!=0) {
    407      *c++='E';			   /* starts with E */
    408      *c++='+';			   /* assume positive */
    409      if (e<0) {
    410	*(c-1)='-';		   /* oops, need '-' */
    411	e=-e;			   /* uInt, please */
    412	}
    413      u=&BIN2CHAR[e*4];		   /* -> length byte */
    414      memcpy(c, u+4-*u, 4);	   /* copy fixed 4 characters [is safe] */
    415      c+=*u;			   /* bump pointer appropriately */
    416      }
    417    *c='\0';			   /* add terminator */
    418    /*printf("res %s\n", string); */
    419    return string;
    420    } /* pre>0 */
    421
    422  /* -5<=pre<=0: here for plain 0.ddd or 0.000ddd forms (can never have E) */
    423  t=c+1-pre;
    424  *(t+1)='\0';				/* can add terminator now */
    425  for (; s>=cstart; s--, t--) *t=*s;	/* shift whole coefficient right */
    426  c=cstart;
    427  *c++='0';				/* always starts with 0. */
    428  *c++='.';
    429  for (; pre<0; pre++) *c++='0';	/* add any 0's after '.' */
    430  /*printf("res %s\n", string); */
    431  return string;
    432  } /* decimal64ToString */
    433
    434/* ------------------------------------------------------------------ */
    435/* to-number -- conversion from numeric string			      */
    436/*								      */
    437/*   decimal64FromString(result, string, set);			      */
    438/*								      */
    439/*  result  is the decimal64 format number which gets the result of   */
    440/*	    the conversion					      */
    441/*  *string is the character string which should contain a valid      */
    442/*	    number (which may be a special value)		      */
    443/*  set	    is the context					      */
    444/*								      */
    445/* The context is supplied to this routine is used for error handling */
    446/* (setting of status and traps) and for the rounding mode, only.     */
    447/* If an error occurs, the result will be a valid decimal64 NaN.      */
    448/* ------------------------------------------------------------------ */
    449decimal64 * decimal64FromString(decimal64 *result, const char *string,
    450				decContext *set) {
    451  decContext dc;			     /* work */
    452  decNumber dn;				     /* .. */
    453
    454  decContextDefault(&dc, DEC_INIT_DECIMAL64); /* no traps, please */
    455  dc.round=set->round;			      /* use supplied rounding */
    456
    457  decNumberFromString(&dn, string, &dc);     /* will round if needed */
    458
    459  decimal64FromNumber(result, &dn, &dc);
    460  if (dc.status!=0) {			     /* something happened */
    461    decContextSetStatus(set, dc.status);     /* .. pass it on */
    462    }
    463  return result;
    464  } /* decimal64FromString */
    465
    466/* ------------------------------------------------------------------ */
    467/* decimal64IsCanonical -- test whether encoding is canonical	      */
    468/*   d64 is the source decimal64				      */
    469/*   returns 1 if the encoding of d64 is canonical, 0 otherwise	      */
    470/* No error is possible.					      */
    471/* ------------------------------------------------------------------ */
    472uint32_t decimal64IsCanonical(const decimal64 *d64) {
    473  decNumber dn;				/* work */
    474  decimal64 canon;			/* .. */
    475  decContext dc;			/* .. */
    476  decContextDefault(&dc, DEC_INIT_DECIMAL64);
    477  decimal64ToNumber(d64, &dn);
    478  decimal64FromNumber(&canon, &dn, &dc);/* canon will now be canonical */
    479  return memcmp(d64, &canon, DECIMAL64_Bytes)==0;
    480  } /* decimal64IsCanonical */
    481
    482/* ------------------------------------------------------------------ */
    483/* decimal64Canonical -- copy an encoding, ensuring it is canonical   */
    484/*   d64 is the source decimal64				      */
    485/*   result is the target (may be the same decimal64)		      */
    486/*   returns result						      */
    487/* No error is possible.					      */
    488/* ------------------------------------------------------------------ */
    489decimal64 * decimal64Canonical(decimal64 *result, const decimal64 *d64) {
    490  decNumber dn;				/* work */
    491  decContext dc;			/* .. */
    492  decContextDefault(&dc, DEC_INIT_DECIMAL64);
    493  decimal64ToNumber(d64, &dn);
    494  decimal64FromNumber(result, &dn, &dc);/* result will now be canonical */
    495  return result;
    496  } /* decimal64Canonical */
    497
    498#if DECTRACE || DECCHECK
    499/* Macros for accessing decimal64 fields.  These assume the
    500   argument is a reference (pointer) to the decimal64 structure,
    501   and the decimal64 is in network byte order (big-endian) */
    502/* Get sign */
    503#define decimal64Sign(d)       ((unsigned)(d)->bytes[0]>>7)
    504
    505/* Get combination field */
    506#define decimal64Comb(d)       (((d)->bytes[0] & 0x7c)>>2)
    507
    508/* Get exponent continuation [does not remove bias] */
    509#define decimal64ExpCon(d)     ((((d)->bytes[0] & 0x03)<<6)	      \
    510			     | ((unsigned)(d)->bytes[1]>>2))
    511
    512/* Set sign [this assumes sign previously 0] */
    513#define decimal64SetSign(d, b) {				      \
    514  (d)->bytes[0]|=((unsigned)(b)<<7);}
    515
    516/* Set exponent continuation [does not apply bias] */
    517/* This assumes range has been checked and exponent previously 0; */
    518/* type of exponent must be unsigned */
    519#define decimal64SetExpCon(d, e) {				      \
    520  (d)->bytes[0]|=(uint8_t)((e)>>6);				      \
    521  (d)->bytes[1]|=(uint8_t)(((e)&0x3F)<<2);}
    522
    523/* ------------------------------------------------------------------ */
    524/* decimal64Show -- display a decimal64 in hexadecimal [debug aid]    */
    525/*   d64 -- the number to show					      */
    526/* ------------------------------------------------------------------ */
    527/* Also shows sign/cob/expconfields extracted */
    528void decimal64Show(const decimal64 *d64) {
    529  char buf[DECIMAL64_Bytes*2+1];
    530  Int i, j=0;
    531
    532  if (DECLITEND) {
    533    for (i=0; i<DECIMAL64_Bytes; i++, j+=2) {
    534      sprintf(&buf[j], "%02x", d64->bytes[7-i]);
    535      }
    536    printf(" D64> %s [S:%d Cb:%02x Ec:%02x] LittleEndian\n", buf,
    537	   d64->bytes[7]>>7, (d64->bytes[7]>>2)&0x1f,
    538	   ((d64->bytes[7]&0x3)<<6)| (d64->bytes[6]>>2));
    539    }
    540   else { /* big-endian */
    541    for (i=0; i<DECIMAL64_Bytes; i++, j+=2) {
    542      sprintf(&buf[j], "%02x", d64->bytes[i]);
    543      }
    544    printf(" D64> %s [S:%d Cb:%02x Ec:%02x] BigEndian\n", buf,
    545	   decimal64Sign(d64), decimal64Comb(d64), decimal64ExpCon(d64));
    546    }
    547  } /* decimal64Show */
    548#endif
    549
    550/* ================================================================== */
    551/* Shared utility routines and tables				      */
    552/* ================================================================== */
    553/* define and include the conversion tables to use for shared code */
    554#if DECDPUN==3
    555  #define DEC_DPD2BIN 1
    556#else
    557  #define DEC_DPD2BCD 1
    558#endif
    559#include "libdecnumber/decDPD.h"
    560
    561/* The maximum number of decNumberUnits needed for a working copy of */
    562/* the units array is the ceiling of digits/DECDPUN, where digits is */
    563/* the maximum number of digits in any of the formats for which this */
    564/* is used.  decimal128.h must not be included in this module, so, as */
    565/* a very special case, that number is defined as a literal here. */
    566#define DECMAX754   34
    567#define DECMAXUNITS ((DECMAX754+DECDPUN-1)/DECDPUN)
    568
    569/* ------------------------------------------------------------------ */
    570/* Combination field lookup tables (uInts to save measurable work)    */
    571/*								      */
    572/*	COMBEXP - 2-bit most-significant-bits of exponent	      */
    573/*		  [11 if an Infinity or NaN]			      */
    574/*	COMBMSD - 4-bit most-significant-digit			      */
    575/*		  [0=Infinity, 1=NaN if COMBEXP=11]		      */
    576/*								      */
    577/* Both are indexed by the 5-bit combination field (0-31)	      */
    578/* ------------------------------------------------------------------ */
    579const uInt COMBEXP[32]={0, 0, 0, 0, 0, 0, 0, 0,
    580			1, 1, 1, 1, 1, 1, 1, 1,
    581			2, 2, 2, 2, 2, 2, 2, 2,
    582			0, 0, 1, 1, 2, 2, 3, 3};
    583const uInt COMBMSD[32]={0, 1, 2, 3, 4, 5, 6, 7,
    584			0, 1, 2, 3, 4, 5, 6, 7,
    585			0, 1, 2, 3, 4, 5, 6, 7,
    586			8, 9, 8, 9, 8, 9, 0, 1};
    587
    588/* ------------------------------------------------------------------ */
    589/* decDigitsToDPD -- pack coefficient into DPD form		      */
    590/*								      */
    591/*   dn	  is the source number (assumed valid, max DECMAX754 digits)  */
    592/*   targ is 1, 2, or 4-element uInt array, which the caller must     */
    593/*	  have cleared to zeros					      */
    594/*   shift is the number of 0 digits to add on the right (normally 0) */
    595/*								      */
    596/* The coefficient must be known small enough to fit.  The full	      */
    597/* coefficient is copied, including the leading 'odd' digit.  This    */
    598/* digit is retrieved and packed into the combination field by the    */
    599/* caller.							      */
    600/*								      */
    601/* The target uInts are altered only as necessary to receive the      */
    602/* digits of the decNumber.  When more than one uInt is needed, they  */
    603/* are filled from left to right (that is, the uInt at offset 0 will  */
    604/* end up with the least-significant digits).			      */
    605/*								      */
    606/* shift is used for 'fold-down' padding.			      */
    607/*								      */
    608/* No error is possible.					      */
    609/* ------------------------------------------------------------------ */
    610#if DECDPUN<=4
    611/* Constant multipliers for divide-by-power-of five using reciprocal */
    612/* multiply, after removing powers of 2 by shifting, and final shift */
    613/* of 17 [we only need up to **4] */
    614static const uInt multies[]={131073, 26215, 5243, 1049, 210};
    615/* QUOT10 -- macro to return the quotient of unit u divided by 10**n */
    616#define QUOT10(u, n) ((((uInt)(u)>>(n))*multies[n])>>17)
    617#endif
    618void decDigitsToDPD(const decNumber *dn, uInt *targ, Int shift) {
    619  Int  cut;		      /* work */
    620  Int  n;		      /* output bunch counter */
    621  Int  digits=dn->digits;     /* digit countdown */
    622  uInt dpd;		      /* densely packed decimal value */
    623  uInt bin;		      /* binary value 0-999 */
    624  uInt *uout=targ;	      /* -> current output uInt */
    625  uInt	uoff=0;		      /* -> current output offset [from right] */
    626  const Unit *inu=dn->lsu;    /* -> current input unit */
    627  Unit	uar[DECMAXUNITS];     /* working copy of units, iff shifted */
    628  #if DECDPUN!=3	      /* not fast path */
    629    Unit in;		      /* current unit */
    630  #endif
    631
    632  if (shift!=0) {	      /* shift towards most significant required */
    633    /* shift the units array to the left by pad digits and copy */
    634    /* [this code is a special case of decShiftToMost, which could */
    635    /* be used instead if exposed and the array were copied first] */
    636    const Unit *source;			/* .. */
    637    Unit  *target, *first;		/* .. */
    638    uInt  next=0;			/* work */
    639
    640    source=dn->lsu+D2U(digits)-1;	/* where msu comes from */
    641    target=uar+D2U(digits)-1+D2U(shift);/* where upper part of first cut goes */
    642    cut=DECDPUN-MSUDIGITS(shift);	/* where to slice */
    643    if (cut==0) {			/* unit-boundary case */
    644      for (; source>=dn->lsu; source--, target--) *target=*source;
    645      }
    646     else {
    647      first=uar+D2U(digits+shift)-1;	/* where msu will end up */
    648      for (; source>=dn->lsu; source--, target--) {
    649	/* split the source Unit and accumulate remainder for next */
    650	#if DECDPUN<=4
    651	  uInt quot=QUOT10(*source, cut);
    652	  uInt rem=*source-quot*DECPOWERS[cut];
    653	  next+=quot;
    654	#else
    655	  uInt rem=*source%DECPOWERS[cut];
    656	  next+=*source/DECPOWERS[cut];
    657	#endif
    658	if (target<=first) *target=(Unit)next; /* write to target iff valid */
    659	next=rem*DECPOWERS[DECDPUN-cut];       /* save remainder for next Unit */
    660	}
    661      } /* shift-move */
    662    /* propagate remainder to one below and clear the rest */
    663    for (; target>=uar; target--) {
    664      *target=(Unit)next;
    665      next=0;
    666      }
    667    digits+=shift;		   /* add count (shift) of zeros added */
    668    inu=uar;			   /* use units in working array */
    669    }
    670
    671  /* now densely pack the coefficient into DPD declets */
    672
    673  #if DECDPUN!=3		   /* not fast path */
    674    in=*inu;			   /* current unit */
    675    cut=0;			   /* at lowest digit */
    676    bin=0;			   /* [keep compiler quiet] */
    677  #endif
    678
    679  for(n=0; digits>0; n++) {	   /* each output bunch */
    680    #if DECDPUN==3		   /* fast path, 3-at-a-time */
    681      bin=*inu;			   /* 3 digits ready for convert */
    682      digits-=3;		   /* [may go negative] */
    683      inu++;			   /* may need another */
    684
    685    #else			   /* must collect digit-by-digit */
    686      Unit dig;			   /* current digit */
    687      Int j;			   /* digit-in-declet count */
    688      for (j=0; j<3; j++) {
    689	#if DECDPUN<=4
    690	  Unit temp=(Unit)((uInt)(in*6554)>>16);
    691	  dig=(Unit)(in-X10(temp));
    692	  in=temp;
    693	#else
    694	  dig=in%10;
    695	  in=in/10;
    696	#endif
    697	if (j==0) bin=dig;
    698	 else if (j==1)	 bin+=X10(dig);
    699	 else /* j==2 */ bin+=X100(dig);
    700	digits--;
    701	if (digits==0) break;	   /* [also protects *inu below] */
    702	cut++;
    703	if (cut==DECDPUN) {inu++; in=*inu; cut=0;}
    704	}
    705    #endif
    706    /* here there are 3 digits in bin, or have used all input digits */
    707
    708    dpd=BIN2DPD[bin];
    709
    710    /* write declet to uInt array */
    711    *uout|=dpd<<uoff;
    712    uoff+=10;
    713    if (uoff<32) continue;	   /* no uInt boundary cross */
    714    uout++;
    715    uoff-=32;
    716    *uout|=dpd>>(10-uoff);	   /* collect top bits */
    717    } /* n declets */
    718  return;
    719  } /* decDigitsToDPD */
    720
    721/* ------------------------------------------------------------------ */
    722/* decDigitsFromDPD -- unpack a format's coefficient		      */
    723/*								      */
    724/*   dn is the target number, with 7, 16, or 34-digit space.	      */
    725/*   sour is a 1, 2, or 4-element uInt array containing only declets  */
    726/*   declets is the number of (right-aligned) declets in sour to      */
    727/*     be processed.  This may be 1 more than the obvious number in   */
    728/*     a format, as any top digit is prefixed to the coefficient      */
    729/*     continuation field.  It also may be as small as 1, as the      */
    730/*     caller may pre-process leading zero declets.		      */
    731/*								      */
    732/* When doing the 'extra declet' case care is taken to avoid writing  */
    733/* extra digits when there are leading zeros, as these could overflow */
    734/* the units array when DECDPUN is not 3.			      */
    735/*								      */
    736/* The target uInts are used only as necessary to process declets     */
    737/* declets into the decNumber.	When more than one uInt is needed,    */
    738/* they are used from left to right (that is, the uInt at offset 0    */
    739/* provides the least-significant digits).			      */
    740/*								      */
    741/* dn->digits is set, but not the sign or exponent.		      */
    742/* No error is possible [the redundant 888 codes are allowed].	      */
    743/* ------------------------------------------------------------------ */
    744void decDigitsFromDPD(decNumber *dn, const uInt *sour, Int declets) {
    745
    746  uInt	dpd;			   /* collector for 10 bits */
    747  Int	n;			   /* counter */
    748  Unit	*uout=dn->lsu;		   /* -> current output unit */
    749  Unit	*last=uout;		   /* will be unit containing msd */
    750  const uInt *uin=sour;		   /* -> current input uInt */
    751  uInt	uoff=0;			   /* -> current input offset [from right] */
    752
    753  #if DECDPUN!=3
    754  uInt	bcd;			   /* BCD result */
    755  uInt	nibble;			   /* work */
    756  Unit	out=0;			   /* accumulator */
    757  Int	cut=0;			   /* power of ten in current unit */
    758  #endif
    759  #if DECDPUN>4
    760  uInt const *pow;		   /* work */
    761  #endif
    762
    763  /* Expand the densely-packed integer, right to left */
    764  for (n=declets-1; n>=0; n--) {   /* count down declets of 10 bits */
    765    dpd=*uin>>uoff;
    766    uoff+=10;
    767    if (uoff>32) {		   /* crossed uInt boundary */
    768      uin++;
    769      uoff-=32;
    770      dpd|=*uin<<(10-uoff);	   /* get waiting bits */
    771      }
    772    dpd&=0x3ff;			   /* clear uninteresting bits */
    773
    774  #if DECDPUN==3
    775    if (dpd==0) *uout=0;
    776     else {
    777      *uout=DPD2BIN[dpd];	   /* convert 10 bits to binary 0-999 */
    778      last=uout;		   /* record most significant unit */
    779      }
    780    uout++;
    781    } /* n */
    782
    783  #else /* DECDPUN!=3 */
    784    if (dpd==0) {		   /* fastpath [e.g., leading zeros] */
    785      /* write out three 0 digits (nibbles); out may have digit(s) */
    786      cut++;
    787      if (cut==DECDPUN) {*uout=out; if (out) {last=uout; out=0;} uout++; cut=0;}
    788      if (n==0) break;		   /* [as below, works even if MSD=0] */
    789      cut++;
    790      if (cut==DECDPUN) {*uout=out; if (out) {last=uout; out=0;} uout++; cut=0;}
    791      cut++;
    792      if (cut==DECDPUN) {*uout=out; if (out) {last=uout; out=0;} uout++; cut=0;}
    793      continue;
    794      }
    795
    796    bcd=DPD2BCD[dpd];		   /* convert 10 bits to 12 bits BCD */
    797
    798    /* now accumulate the 3 BCD nibbles into units */
    799    nibble=bcd & 0x00f;
    800    if (nibble) out=(Unit)(out+nibble*DECPOWERS[cut]);
    801    cut++;
    802    if (cut==DECDPUN) {*uout=out; if (out) {last=uout; out=0;} uout++; cut=0;}
    803    bcd>>=4;
    804
    805    /* if this is the last declet and the remaining nibbles in bcd */
    806    /* are 00 then process no more nibbles, because this could be */
    807    /* the 'odd' MSD declet and writing any more Units would then */
    808    /* overflow the unit array */
    809    if (n==0 && !bcd) break;
    810
    811    nibble=bcd & 0x00f;
    812    if (nibble) out=(Unit)(out+nibble*DECPOWERS[cut]);
    813    cut++;
    814    if (cut==DECDPUN) {*uout=out; if (out) {last=uout; out=0;} uout++; cut=0;}
    815    bcd>>=4;
    816
    817    nibble=bcd & 0x00f;
    818    if (nibble) out=(Unit)(out+nibble*DECPOWERS[cut]);
    819    cut++;
    820    if (cut==DECDPUN) {*uout=out; if (out) {last=uout; out=0;} uout++; cut=0;}
    821    } /* n */
    822  if (cut!=0) {				/* some more left over */
    823    *uout=out;				/* write out final unit */
    824    if (out) last=uout;			/* and note if non-zero */
    825    }
    826  #endif
    827
    828  /* here, last points to the most significant unit with digits; */
    829  /* inspect it to get the final digits count -- this is essentially */
    830  /* the same code as decGetDigits in decNumber.c */
    831  dn->digits=(last-dn->lsu)*DECDPUN+1;	/* floor of digits, plus */
    832					/* must be at least 1 digit */
    833  #if DECDPUN>1
    834  if (*last<10) return;			/* common odd digit or 0 */
    835  dn->digits++;				/* must be 2 at least */
    836  #if DECDPUN>2
    837  if (*last<100) return;		/* 10-99 */
    838  dn->digits++;				/* must be 3 at least */
    839  #if DECDPUN>3
    840  if (*last<1000) return;		/* 100-999 */
    841  dn->digits++;				/* must be 4 at least */
    842  #if DECDPUN>4
    843  for (pow=&DECPOWERS[4]; *last>=*pow; pow++) dn->digits++;
    844  #endif
    845  #endif
    846  #endif
    847  #endif
    848  return;
    849  } /*decDigitsFromDPD */