[mirror_qemu.git] / libdecnumber / dpd / decimal32.c

/* Decimal 32-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 32-bit format module					      */
/* ------------------------------------------------------------------ */
/* This module comprises the routines for decimal32 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  7      /* make decNumbers with space for 7 */
#include "libdecnumber/decNumber.h"
#include "libdecnumber/decNumberLocal.h"
#include "libdecnumber/dpd/decimal32.h"

/* Utility tables and routines [in decimal64.c] */
extern const uInt   COMBEXP[32], COMBMSD[32];
extern const uByte  BIN2CHAR[4001];

extern void decDigitsToDPD(const decNumber *, uInt *, Int);
extern void decDigitsFromDPD(decNumber *, const uInt *, Int);

#if DECTRACE || DECCHECK
void decimal32Show(const decimal32 *);		  /* 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))

/* ------------------------------------------------------------------ */
/* decimal32FromNumber -- convert decNumber to decimal32	      */
/*								      */
/*   ds is the target decimal32					      */
/*   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 DECIMAL32_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.      */
/* ------------------------------------------------------------------ */
decimal32 * decimal32FromNumber(decimal32 *d32, 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 targ=0;			   /* target 32-bit */

  /* 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 */
  /* decimal32] */
  ae=dn->exponent+dn->digits-1;		     /* [0 if special] */
  if (dn->digits>DECIMAL32_Pmax		     /* too many digits */
   || ae>DECIMAL32_Emax			     /* likely overflow */
   || ae<DECIMAL32_Emin) {		     /* likely underflow */
    decContextDefault(&dc, DEC_INIT_DECIMAL32); /* [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) targ=DECIMAL_Inf<<24;
     else {					  /* sNaN or qNaN */
      if ((*dn->lsu!=0 || dn->digits>1)		  /* non-zero coefficient */
       && (dn->digits<DECIMAL32_Pmax)) {	  /* coefficient fits */
	decDigitsToDPD(dn, &targ, 0);
	}
      if (dn->bits&DECNAN) targ|=DECIMAL_NaN<<24;
       else targ|=DECIMAL_sNaN<<24;
      } /* a NaN */
    } /* special */

   else { /* is finite */
    if (decNumberIsZero(dn)) {		     /* is a zero */
      /* set and clamp exponent */
      if (dn->exponent<-DECIMAL32_Bias) {
	exp=0;				     /* low clamp */
	status|=DEC_Clamped;
	}
       else {
	exp=dn->exponent+DECIMAL32_Bias;     /* bias exponent */
	if (exp>DECIMAL32_Ehigh) {	     /* top clamp */
	  exp=DECIMAL32_Ehigh;
	  status|=DEC_Clamped;
	  }
	}
      comb=(exp>>3) & 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+DECIMAL32_Bias);	  /* bias exponent */
      if (exp>DECIMAL32_Ehigh) {		  /* fold-down case */
	pad=exp-DECIMAL32_Ehigh;
	exp=DECIMAL32_Ehigh;			  /* [to maximum] */
	status|=DEC_Clamped;
	}

      /* fastpath common case */
      if (DECDPUN==3 && pad==0) {
	targ=BIN2DPD[dn->lsu[0]];
	if (dn->digits>3) targ|=(uInt)(BIN2DPD[dn->lsu[1]])<<10;
	msd=(dn->digits==7 ? dn->lsu[2] : 0);
	}
       else { /* general case */
	decDigitsToDPD(dn, &targ, pad);
	/* save and clear the top digit */
	msd=targ>>20;
	targ&=0x000fffff;
	}

      /* create the combination field */
      if (msd>=8) comb=0x18 | ((exp>>5) & 0x06) | (msd & 0x01);
	     else comb=((exp>>3) & 0x18) | msd;
      }
    targ|=comb<<26;		   /* add combination field .. */
    targ|=(exp&0x3f)<<20;	   /* .. and exponent continuation */
    } /* finite */

  if (dn->bits&DECNEG) targ|=0x80000000;  /* add sign bit */

  /* now write to storage; this is endian */
  pu=(uInt *)d32->bytes;	   /* overlay */
  *pu=targ;			   /* directly store the int */

  if (status!=0) decContextSetStatus(set, status); /* pass on status */
  /* decimal32Show(d32); */
  return d32;
  } /* decimal32FromNumber */

/* ------------------------------------------------------------------ */
/* decimal32ToNumber -- convert decimal32 to decNumber		      */
/*   d32 is the source decimal32				      */
/*   dn is the target number, with appropriate space		      */
/* No error is possible.					      */
/* ------------------------------------------------------------------ */
decNumber * decimal32ToNumber(const decimal32 *d32, decNumber *dn) {
  uInt msd;			   /* coefficient MSD */
  uInt exp;			   /* exponent top two bits */
  uInt comb;			   /* combination field */
  uInt sour;			   /* source 32-bit */
  const uInt *pu;		   /* work */

  /* load source from storage; this is endian */
  pu=(const uInt *)d32->bytes;	   /* overlay */
  sour=*pu;			   /* directly load the int */

  comb=(sour>>26)&0x1f;		   /* combination field */

  decNumberZero(dn);		   /* clean number */
  if (sour&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 (sour&0x02000000) dn->bits|=DECSNAN;
    else dn->bits|=DECNAN;
    msd=0;			   /* no top digit */
    }
   else {			   /* is a finite number */
    dn->exponent=(exp<<6)+((sour>>20)&0x3f)-DECIMAL32_Bias; /* unbiased */
    }

  /* get the coefficient */
  sour&=0x000fffff;		   /* clean coefficient continuation */
  if (msd) {			   /* non-zero msd */
    sour|=msd<<20;		   /* prefix to coefficient */
    decDigitsFromDPD(dn, &sour, 3); /* process 3 declets */
    return dn;
    }
  /* msd=0 */
  if (!sour) return dn;		   /* easy: coefficient is 0 */
  if (sour&0x000ffc00)		   /* need 2 declets? */
    decDigitsFromDPD(dn, &sour, 2); /* process 2 declets */
   else
    decDigitsFromDPD(dn, &sour, 1); /* process 1 declet */
  return dn;
  } /* decimal32ToNumber */

/* ------------------------------------------------------------------ */
/* to-scientific-string -- conversion to numeric string		      */
/* to-engineering-string -- conversion to numeric string	      */
/*								      */
/*   decimal32ToString(d32, string);				      */
/*   decimal32ToEngString(d32, string);				      */
/*								      */
/*  d32 is the decimal32 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 * decimal32ToEngString(const decimal32 *d32, char *string){
  decNumber dn;				/* work */
  decimal32ToNumber(d32, &dn);
  decNumberToEngString(&dn, string);
  return string;
  } /* decimal32ToEngString */

char * decimal32ToString(const decimal32 *d32, 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 */
  const uByte *u;		   /* .. */
  char *s, *t;			   /* .. (source, target) */
  Int  dpd;			   /* .. */
  Int  pre, e;			   /* .. */
  uInt sour;			   /* source 32-bit */

  /* load source from storage; this is endian */
  pu=(const uInt *)d32->bytes;	   /* overlay */
  sour=*pu;			   /* directly load the int */

  c=string;			   /* where result will go */
  if (((Int)sour)<0) *c++='-';	   /* handle sign */

  comb=(sour>>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 (sour&0x02000000) *c++='s'; /* sNaN */
    strcpy(c, "NaN");		   /* complete word */
    c+=3;			   /* step past */
    if ((sour&0x000fffff)==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<<6)+((sour>>20)&0x3f)-DECIMAL32_Bias; /* unbiased */

  /* convert 7 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=(sour>>10)&0x3ff;		   /* declet 1 */
  dpd2char;
  dpd=(sour)&0x3ff;		   /* declet 2 */
  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 (E-101 case) */
    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;
  } /* decimal32ToString */

/* ------------------------------------------------------------------ */
/* to-number -- conversion from numeric string			      */
/*								      */
/*   decimal32FromString(result, string, set);			      */
/*								      */
/*  result  is the decimal32 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 decimal32 NaN.      */
/* ------------------------------------------------------------------ */
decimal32 * decimal32FromString(decimal32 *result, const char *string,
				decContext *set) {
  decContext dc;			     /* work */
  decNumber dn;				     /* .. */

  decContextDefault(&dc, DEC_INIT_DECIMAL32); /* no traps, please */
  dc.round=set->round;			      /* use supplied rounding */

  decNumberFromString(&dn, string, &dc);     /* will round if needed */
  decimal32FromNumber(result, &dn, &dc);
  if (dc.status!=0) {			     /* something happened */
    decContextSetStatus(set, dc.status);     /* .. pass it on */
    }
  return result;
  } /* decimal32FromString */

/* ------------------------------------------------------------------ */
/* decimal32IsCanonical -- test whether encoding is canonical	      */
/*   d32 is the source decimal32				      */
/*   returns 1 if the encoding of d32 is canonical, 0 otherwise	      */
/* No error is possible.					      */
/* ------------------------------------------------------------------ */
uint32_t decimal32IsCanonical(const decimal32 *d32) {
  decNumber dn;				/* work */
  decimal32 canon;			/* .. */
  decContext dc;			/* .. */
  decContextDefault(&dc, DEC_INIT_DECIMAL32);
  decimal32ToNumber(d32, &dn);
  decimal32FromNumber(&canon, &dn, &dc);/* canon will now be canonical */
  return memcmp(d32, &canon, DECIMAL32_Bytes)==0;
  } /* decimal32IsCanonical */

/* ------------------------------------------------------------------ */
/* decimal32Canonical -- copy an encoding, ensuring it is canonical   */
/*   d32 is the source decimal32				      */
/*   result is the target (may be the same decimal32)		      */
/*   returns result						      */
/* No error is possible.					      */
/* ------------------------------------------------------------------ */
decimal32 * decimal32Canonical(decimal32 *result, const decimal32 *d32) {
  decNumber dn;				/* work */
  decContext dc;			/* .. */
  decContextDefault(&dc, DEC_INIT_DECIMAL32);
  decimal32ToNumber(d32, &dn);
  decimal32FromNumber(result, &dn, &dc);/* result will now be canonical */
  return result;
  } /* decimal32Canonical */

#if DECTRACE || DECCHECK
/* Macros for accessing decimal32 fields.  These assume the argument
   is a reference (pointer) to the decimal32 structure, and the
   decimal32 is in network byte order (big-endian) */
/* Get sign */
#define decimal32Sign(d)       ((unsigned)(d)->bytes[0]>>7)

/* Get combination field */
#define decimal32Comb(d)       (((d)->bytes[0] & 0x7c)>>2)

/* Get exponent continuation [does not remove bias] */
#define decimal32ExpCon(d)     ((((d)->bytes[0] & 0x03)<<4)	      \
			     | ((unsigned)(d)->bytes[1]>>4))

/* Set sign [this assumes sign previously 0] */
#define decimal32SetSign(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 decimal32SetExpCon(d, e) {				      \
  (d)->bytes[0]|=(uint8_t)((e)>>4);				      \
  (d)->bytes[1]|=(uint8_t)(((e)&0x0F)<<4);}

/* ------------------------------------------------------------------ */
/* decimal32Show -- display a decimal32 in hexadecimal [debug aid]    */
/*   d32 -- the number to show					      */
/* ------------------------------------------------------------------ */
/* Also shows sign/cob/expconfields extracted - valid bigendian only */
void decimal32Show(const decimal32 *d32) {
  char buf[DECIMAL32_Bytes*2+1];
  Int i, j=0;

  if (DECLITEND) {
    for (i=0; i<DECIMAL32_Bytes; i++, j+=2) {
      sprintf(&buf[j], "%02x", d32->bytes[3-i]);
      }
    printf(" D32> %s [S:%d Cb:%02x Ec:%02x] LittleEndian\n", buf,
	   d32->bytes[3]>>7, (d32->bytes[3]>>2)&0x1f,
	   ((d32->bytes[3]&0x3)<<4)| (d32->bytes[2]>>4));
    }
   else {
    for (i=0; i<DECIMAL32_Bytes; i++, j+=2) {
      sprintf(&buf[j], "%02x", d32->bytes[i]);
      }
    printf(" D32> %s [S:%d Cb:%02x Ec:%02x] BigEndian\n", buf,
	   decimal32Sign(d32), decimal32Comb(d32), decimal32ExpCon(d32));
    }
  } /* decimal32Show */
#endif
Commit	Line	Data
72ac97cd TM	1	/* Decimal 32-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 32-bit format module */
	33	/* ------------------------------------------------------------------ */
	34	/* This module comprises the routines for decimal32 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	/* ------------------------------------------------------------------ */
7a4e543d	42	#include "qemu/osdep.h"
72ac97cd	43
0f2d3732	44	#include "libdecnumber/dconfig.h"
72ac97cd	45	#define DECNUMDIGITS 7 /* make decNumbers with space for 7 */
0f2d3732 TM	46	#include "libdecnumber/decNumber.h"
	47	#include "libdecnumber/decNumberLocal.h"
	48	#include "libdecnumber/dpd/decimal32.h"
72ac97cd TM	49
	50	/* Utility tables and routines [in decimal64.c] */
	51	extern const uInt COMBEXP[32], COMBMSD[32];
72ac97cd TM	52	extern const uByte BIN2CHAR[4001];
	53
	54	extern void decDigitsToDPD(const decNumber , uInt , Int);
	55	extern void decDigitsFromDPD(decNumber , const uInt , Int);
	56
	57	#if DECTRACE \|\| DECCHECK
	58	void decimal32Show(const decimal32 ); / for debug */
	59	extern 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	/* ------------------------------------------------------------------ */
	67	/* decimal32FromNumber -- convert decNumber to decimal32 */
	68	/* */
	69	/* ds is the target decimal32 */
	70	/* dn is the source number (assumed valid) */
	71	/* set is the context, used only for reporting errors */
	72	/* */
	73	/* The set argument is used only for status reporting and for the */
	74	/* rounding mode (used if the coefficient is more than DECIMAL32_Pmax */
	75	/* digits or an overflow is detected). If the exponent is out of the */
	76	/* valid range then Overflow or Underflow will be raised. */
	77	/* After Underflow a subnormal result is possible. */
	78	/* */
	79	/* DEC_Clamped is set if the number has to be 'folded down' to fit, */
	80	/* by reducing its exponent and multiplying the coefficient by a */
	81	/* power of ten, or if the exponent on a zero had to be clamped. */
	82	/* ------------------------------------------------------------------ */
	83	decimal32 * decimal32FromNumber(decimal32 d32, const decNumber dn,
	84	decContext *set) {
	85	uInt status=0; /* status accumulator */
	86	Int ae; /* adjusted exponent */
	87	decNumber dw; /* work */
	88	decContext dc; /* .. */
	89	uInt pu; / .. */
	90	uInt comb, exp; /* .. */
	91	uInt targ=0; /* target 32-bit */
	92
	93	/* If the number has too many digits, or the exponent could be */
	94	/* out of range then reduce the number under the appropriate */
	95	/* constraints. This could push the number to Infinity or zero, */
	96	/* so this check and rounding must be done before generating the */
	97	/* decimal32] */
	98	ae=dn->exponent+dn->digits-1; /* [0 if special] */
	99	if (dn->digits>DECIMAL32_Pmax /* too many digits */
	100	\|\| ae>DECIMAL32_Emax /* likely overflow */
	101	\|\| ae<DECIMAL32_Emin) { /* likely underflow */
	102	decContextDefault(&dc, DEC_INIT_DECIMAL32); /* [no traps] */
	103	dc.round=set->round; /* use supplied rounding */
	104	decNumberPlus(&dw, dn, &dc); /* (round and check) */
	105	/* [this changes -0 to 0, so enforce the sign...] */
	106	dw.bits\|=dn->bits&DECNEG;
	107	status=dc.status; /* save status */
	108	dn=&dw; /* use the work number */
	109	} /* maybe out of range */
	110
	111	if (dn->bits&DECSPECIAL) { /* a special value */
	112	if (dn->bits&DECINF) targ=DECIMAL_Inf<<24;
	113	else { /* sNaN or qNaN */
	114	if ((dn->lsu!=0 \|\| dn->digits>1) / non-zero coefficient */
	115	&& (dn->digits<DECIMAL32_Pmax)) { /* coefficient fits */
116	decDigitsToDPD(dn, &targ, 0);
117	}
118	if (dn->bits&DECNAN) targ\|=DECIMAL_NaN<<24;
119	else targ\|=DECIMAL_sNaN<<24;
120	} /* a NaN */
121	} /* special */
122
123	else { /* is finite */
124	if (decNumberIsZero(dn)) { /* is a zero */
125	/* set and clamp exponent */
126	if (dn->exponent<-DECIMAL32_Bias) {
127	exp=0; /* low clamp */
128	status\|=DEC_Clamped;
129	}
130	else {
131	exp=dn->exponent+DECIMAL32_Bias; /* bias exponent */
132	if (exp>DECIMAL32_Ehigh) { /* top clamp */
133	exp=DECIMAL32_Ehigh;
134	status\|=DEC_Clamped;
135	}
136	}
137	comb=(exp>>3) & 0x18; /* msd=0, exp top 2 bits .. */
138	}
139	else { /* non-zero finite number */
140	uInt msd; /* work */
141	Int pad=0; /* coefficient pad digits */
142
143	/* the dn is known to fit, but it may need to be padded */
144	exp=(uInt)(dn->exponent+DECIMAL32_Bias); /* bias exponent */
145	if (exp>DECIMAL32_Ehigh) { /* fold-down case */
146	pad=exp-DECIMAL32_Ehigh;
147	exp=DECIMAL32_Ehigh; /* [to maximum] */
148	status\|=DEC_Clamped;
149	}
150
151	/* fastpath common case */
152	if (DECDPUN==3 && pad==0) {
153	targ=BIN2DPD[dn->lsu[0]];
154	if (dn->digits>3) targ\|=(uInt)(BIN2DPD[dn->lsu[1]])<<10;
155	msd=(dn->digits==7 ? dn->lsu[2] : 0);
156	}
157	else { /* general case */
158	decDigitsToDPD(dn, &targ, pad);
159	/* save and clear the top digit */
160	msd=targ>>20;
161	targ&=0x000fffff;
162	}
163
164	/* create the combination field */
165	if (msd>=8) comb=0x18 \| ((exp>>5) & 0x06) \| (msd & 0x01);
166	else comb=((exp>>3) & 0x18) \| msd;
167	}
168	targ\|=comb<<26; /* add combination field .. */
169	targ\|=(exp&0x3f)<<20; /* .. and exponent continuation */
170	} /* finite */
171
172	if (dn->bits&DECNEG) targ\|=0x80000000; /* add sign bit */
173
174	/* now write to storage; this is endian */
175	pu=(uInt )d32->bytes; / overlay */
176	pu=targ; / directly store the int */
177
178	if (status!=0) decContextSetStatus(set, status); /* pass on status */
179	/* decimal32Show(d32); */
180	return d32;
181	} /* decimal32FromNumber */
182
183	/* ------------------------------------------------------------------ */
184	/* decimal32ToNumber -- convert decimal32 to decNumber */
185	/* d32 is the source decimal32 */
186	/* dn is the target number, with appropriate space */
187	/* No error is possible. */
188	/* ------------------------------------------------------------------ */
189	decNumber * decimal32ToNumber(const decimal32 d32, decNumber dn) {
190	uInt msd; /* coefficient MSD */
191	uInt exp; /* exponent top two bits */
192	uInt comb; /* combination field */
193	uInt sour; /* source 32-bit */
194	const uInt pu; / work */
195
196	/* load source from storage; this is endian */
197	pu=(const uInt )d32->bytes; / overlay */
198	sour=pu; / directly load the int */
199
200	comb=(sour>>26)&0x1f; /* combination field */
201
202	decNumberZero(dn); /* clean number */
203	if (sour&0x80000000) dn->bits=DECNEG; /* set sign if negative */
204
205	msd=COMBMSD[comb]; /* decode the combination field */
206	exp=COMBEXP[comb]; /* .. */
207
208	if (exp==3) { /* is a special */
209	if (msd==0) {
210	dn->bits\|=DECINF;
211	return dn; /* no coefficient needed */
212	}
213	else if (sour&0x02000000) dn->bits\|=DECSNAN;
214	else dn->bits\|=DECNAN;
215	msd=0; /* no top digit */
216	}
217	else { /* is a finite number */
218	dn->exponent=(exp<<6)+((sour>>20)&0x3f)-DECIMAL32_Bias; /* unbiased */
219	}
220
221	/* get the coefficient */
222	sour&=0x000fffff; /* clean coefficient continuation */
223	if (msd) { /* non-zero msd */
224	sour\|=msd<<20; /* prefix to coefficient */
225	decDigitsFromDPD(dn, &sour, 3); /* process 3 declets */
226	return dn;
227	}
228	/* msd=0 */
229	if (!sour) return dn; /* easy: coefficient is 0 */
230	if (sour&0x000ffc00) /* need 2 declets? */
231	decDigitsFromDPD(dn, &sour, 2); /* process 2 declets */
232	else
233	decDigitsFromDPD(dn, &sour, 1); /* process 1 declet */
234	return dn;
235	} /* decimal32ToNumber */
236
237	/* ------------------------------------------------------------------ */
238	/* to-scientific-string -- conversion to numeric string */
239	/* to-engineering-string -- conversion to numeric string */
240	/* */
241	/* decimal32ToString(d32, string); */
242	/* decimal32ToEngString(d32, string); */
243	/* */
244	/* d32 is the decimal32 format number to convert */
245	/* string is the string where the result will be laid out */
246	/* */
247	/* string must be at least 24 characters */
248	/* */
249	/* No error is possible, and no status can be set. */
250	/* ------------------------------------------------------------------ */
251	char * decimal32ToEngString(const decimal32 d32, char string){
252	decNumber dn; /* work */
253	decimal32ToNumber(d32, &dn);
254	decNumberToEngString(&dn, string);
255	return string;
256	} /* decimal32ToEngString */
257
258	char * decimal32ToString(const decimal32 d32, char string){
259	uInt msd; /* coefficient MSD */
260	Int exp; /* exponent top two bits or full */
261	uInt comb; /* combination field */
262	char cstart; / coefficient start */
263	char c; / output pointer in string */
264	const uInt pu; / work */
265	const uByte u; / .. */
266	char s, t; /* .. (source, target) */
267	Int dpd; /* .. */
268	Int pre, e; /* .. */
269	uInt sour; /* source 32-bit */
270
271	/* load source from storage; this is endian */
272	pu=(const uInt )d32->bytes; / overlay */
273	sour=pu; / directly load the int */
274
275	c=string; /* where result will go */
276	if (((Int)sour)<0) c++='-'; / handle sign */
277
278	comb=(sour>>26)&0x1f; /* combination field */
279	msd=COMBMSD[comb]; /* decode the combination field */
280	exp=COMBEXP[comb]; /* .. */
281
282	if (exp==3) {
283	if (msd==0) { /* infinity */
284	strcpy(c, "Inf");
285	strcpy(c+3, "inity");
286	return string; /* easy */
287	}
288	if (sour&0x02000000) c++='s'; / sNaN */
289	strcpy(c, "NaN"); /* complete word */
290	c+=3; /* step past */
291	if ((sour&0x000fffff)==0) return string; /* zero payload */
292	/* otherwise drop through to add integer; set correct exp */
293	exp=0; msd=0; /* setup for following code */
294	}
295	else exp=(exp<<6)+((sour>>20)&0x3f)-DECIMAL32_Bias; /* unbiased */
296
297	/* convert 7 digits of significand to characters */
298	cstart=c; /* save start of coefficient */
299	if (msd) c++='0'+(char)msd; / non-zero most significant digit */
300
301	/* Now decode the declets. After extracting each one, it is */
302	/* decoded to binary and then to a 4-char sequence by table lookup; */
303	/* the 4-chars are a 1-char length (significant digits, except 000 */
304	/* has length 0). This allows us to left-align the first declet */
305	/* with non-zero content, then remaining ones are full 3-char */
306	/* length. We use fixed-length memcpys because variable-length */
307	/* causes a subroutine call in GCC. (These are length 4 for speed */
308	/* and are safe because the array has an extra terminator byte.) */
309	#define dpd2char u=&BIN2CHAR[DPD2BIN[dpd]*4]; \
310	if (c!=cstart) {memcpy(c, u+1, 4); c+=3;} \
311	else if (u) {memcpy(c, u+4-u, 4); c+=*u;}
312
313	dpd=(sour>>10)&0x3ff; /* declet 1 */
314	dpd2char;
315	dpd=(sour)&0x3ff; /* declet 2 */
316	dpd2char;
317
318	if (c==cstart) c++='0'; / all zeros -- make 0 */
319
320	if (exp==0) { /* integer or NaN case -- easy */
321	c='\0'; / terminate */
322	return string;
323	}
324
325	/* non-0 exponent */
326	e=0; /* assume no E */
327	pre=c-cstart+exp;
328	/* [here, pre-exp is the digits count (==1 for zero)] */
329	if (exp>0 \|\| pre<-5) { /* need exponential form */
330	e=pre-1; /* calculate E value */
331	pre=1; /* assume one digit before '.' */
332	} /* exponential form */
333
334	/* modify the coefficient, adding 0s, '.', and E+nn as needed */
335	s=c-1; /* source (LSD) */
336	if (pre>0) { /* ddd.ddd (plain), perhaps with E */
337	char *dotat=cstart+pre;
338	if (dotat<c) { /* if embedded dot needed... */
339	t=c; /* target */
340	for (; s>=dotat; s--, t--) t=s; /* open the gap; leave t at gap */
341	t='.'; / insert the dot */
342	c++; /* length increased by one */
343	}
344
345	/* finally add the E-part, if needed; it will never be 0, and has */
346	/* a maximum length of 3 digits (E-101 case) */
347	if (e!=0) {
348	c++='E'; / starts with E */
349	c++='+'; / assume positive */
350	if (e<0) {
351	(c-1)='-'; / oops, need '-' */
352	e=-e; /* uInt, please */
353	}
354	u=&BIN2CHAR[e4]; / -> length byte */
355	memcpy(c, u+4-u, 4); / copy fixed 4 characters [is safe] */
356	c+=u; / bump pointer appropriately */
357	}
358	c='\0'; / add terminator */
359	/printf("res %s\n", string); /
360	return string;
361	} /* pre>0 */
362
363	/* -5<=pre<=0: here for plain 0.ddd or 0.000ddd forms (can never have E) */
364	t=c+1-pre;
365	(t+1)='\0'; / can add terminator now */
366	for (; s>=cstart; s--, t--) t=s; /* shift whole coefficient right */
367	c=cstart;
368	c++='0'; / always starts with 0. */
369	*c++='.';
370	for (; pre<0; pre++) c++='0'; / add any 0's after '.' */
371	/printf("res %s\n", string); /
372	return string;
373	} /* decimal32ToString */
374
375	/* ------------------------------------------------------------------ */
376	/* to-number -- conversion from numeric string */
377	/* */
378	/* decimal32FromString(result, string, set); */
379	/* */
380	/* result is the decimal32 format number which gets the result of */
381	/* the conversion */
382	/* string is the character string which should contain a valid /
383	/* number (which may be a special value) */
384	/* set is the context */
385	/* */
386	/* The context is supplied to this routine is used for error handling */
387	/* (setting of status and traps) and for the rounding mode, only. */
388	/* If an error occurs, the result will be a valid decimal32 NaN. */
389	/* ------------------------------------------------------------------ */
390	decimal32 * decimal32FromString(decimal32 result, const char string,
391	decContext *set) {
392	decContext dc; /* work */
393	decNumber dn; /* .. */
394
395	decContextDefault(&dc, DEC_INIT_DECIMAL32); /* no traps, please */
396	dc.round=set->round; /* use supplied rounding */
397
398	decNumberFromString(&dn, string, &dc); /* will round if needed */
399	decimal32FromNumber(result, &dn, &dc);
400	if (dc.status!=0) { /* something happened */
401	decContextSetStatus(set, dc.status); /* .. pass it on */
402	}
403	return result;
404	} /* decimal32FromString */
405
406	/* ------------------------------------------------------------------ */
407	/* decimal32IsCanonical -- test whether encoding is canonical */
408	/* d32 is the source decimal32 */
409	/* returns 1 if the encoding of d32 is canonical, 0 otherwise */
410	/* No error is possible. */
411	/* ------------------------------------------------------------------ */
412	uint32_t decimal32IsCanonical(const decimal32 *d32) {
413	decNumber dn; /* work */
414	decimal32 canon; /* .. */
415	decContext dc; /* .. */
416	decContextDefault(&dc, DEC_INIT_DECIMAL32);
417	decimal32ToNumber(d32, &dn);
418	decimal32FromNumber(&canon, &dn, &dc);/* canon will now be canonical */
419	return memcmp(d32, &canon, DECIMAL32_Bytes)==0;
420	} /* decimal32IsCanonical */
421
422	/* ------------------------------------------------------------------ */
423	/* decimal32Canonical -- copy an encoding, ensuring it is canonical */
424	/* d32 is the source decimal32 */
425	/* result is the target (may be the same decimal32) */
426	/* returns result */
427	/* No error is possible. */
428	/* ------------------------------------------------------------------ */
429	decimal32 * decimal32Canonical(decimal32 result, const decimal32 d32) {
430	decNumber dn; /* work */
431	decContext dc; /* .. */
432	decContextDefault(&dc, DEC_INIT_DECIMAL32);
433	decimal32ToNumber(d32, &dn);
434	decimal32FromNumber(result, &dn, &dc);/* result will now be canonical */
435	return result;
436	} /* decimal32Canonical */
437
438	#if DECTRACE \|\| DECCHECK
439	/* Macros for accessing decimal32 fields. These assume the argument
440	is a reference (pointer) to the decimal32 structure, and the
441	decimal32 is in network byte order (big-endian) */
442	/* Get sign */
443	#define decimal32Sign(d) ((unsigned)(d)->bytes[0]>>7)
444
445	/* Get combination field */
446	#define decimal32Comb(d) (((d)->bytes[0] & 0x7c)>>2)
447
448	/* Get exponent continuation [does not remove bias] */
449	#define decimal32ExpCon(d) ((((d)->bytes[0] & 0x03)<<4) \
450	\| ((unsigned)(d)->bytes[1]>>4))
451
452	/* Set sign [this assumes sign previously 0] */
453	#define decimal32SetSign(d, b) { \
454	(d)->bytes[0]\|=((unsigned)(b)<<7);}
455
456	/* Set exponent continuation [does not apply bias] */
457	/* This assumes range has been checked and exponent previously 0; */
458	/* type of exponent must be unsigned */
459	#define decimal32SetExpCon(d, e) { \
460	(d)->bytes[0]\|=(uint8_t)((e)>>4); \
461	(d)->bytes[1]\|=(uint8_t)(((e)&0x0F)<<4);}
462
463	/* ------------------------------------------------------------------ */
464	/* decimal32Show -- display a decimal32 in hexadecimal [debug aid] */
465	/* d32 -- the number to show */
466	/* ------------------------------------------------------------------ */
467	/* Also shows sign/cob/expconfields extracted - valid bigendian only */
468	void decimal32Show(const decimal32 *d32) {
469	char buf[DECIMAL32_Bytes*2+1];
470	Int i, j=0;
471
472	if (DECLITEND) {
473	for (i=0; i<DECIMAL32_Bytes; i++, j+=2) {
474	sprintf(&buf[j], "%02x", d32->bytes[3-i]);
475	}
476	printf(" D32> %s [S:%d Cb:%02x Ec:%02x] LittleEndian\n", buf,
477	d32->bytes[3]>>7, (d32->bytes[3]>>2)&0x1f,
478	((d32->bytes[3]&0x3)<<4)\| (d32->bytes[2]>>4));
479	}
480	else {
481	for (i=0; i<DECIMAL32_Bytes; i++, j+=2) {
482	sprintf(&buf[j], "%02x", d32->bytes[i]);
483	}
484	printf(" D32> %s [S:%d Cb:%02x Ec:%02x] BigEndian\n", buf,
485	decimal32Sign(d32), decimal32Comb(d32), decimal32ExpCon(d32));
486	}
487	} /* decimal32Show */
488	#endif