484 lines
19 KiB
C
484 lines
19 KiB
C
/* Decimal 32-bit format module for the decNumber C Library.
|
|
Copyright (C) 2005-2014 Free Software Foundation, Inc.
|
|
Contributed by IBM Corporation. Author Mike Cowlishaw.
|
|
|
|
This file is part of GCC.
|
|
|
|
GCC is free software; you can redistribute it and/or modify it under
|
|
the terms of the GNU General Public License as published by the Free
|
|
Software Foundation; either version 3, or (at your option) any later
|
|
version.
|
|
|
|
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
|
|
WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
|
for more details.
|
|
|
|
Under Section 7 of GPL version 3, you are granted additional
|
|
permissions described in the GCC Runtime Library Exception, version
|
|
3.1, as published by the Free Software Foundation.
|
|
|
|
You should have received a copy of the GNU General Public License and
|
|
a copy of the GCC Runtime Library Exception along with this program;
|
|
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* Decimal 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 <string.h> /* [for memset/memcpy] */
|
|
#include <stdio.h> /* [for printf] */
|
|
|
|
#include "dconfig.h" /* GCC definitions */
|
|
#define DECNUMDIGITS 7 /* make decNumbers with space for 7 */
|
|
#include "decNumber.h" /* base number library */
|
|
#include "decNumberLocal.h" /* decNumber local types, etc. */
|
|
#include "decimal32.h" /* our primary include */
|
|
|
|
/* Utility tables and routines [in decimal64.c] */
|
|
extern const uInt COMBEXP[32], COMBMSD[32];
|
|
extern const uShort DPD2BIN[1024];
|
|
extern const uShort BIN2DPD[1000];
|
|
extern const uByte BIN2CHAR[4001];
|
|
|
|
extern void 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 comb, exp; /* .. */
|
|
uInt uiwork; /* for macros */
|
|
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 */
|
|
UBFROMUI(d32->bytes, 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 */
|
|
uInt uiwork; /* for macros */
|
|
|
|
/* load source from storage; this is endian */
|
|
sour=UBTOUI(d32->bytes); /* 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 uByte *u; /* work */
|
|
char *s, *t; /* .. (source, target) */
|
|
Int dpd; /* .. */
|
|
Int pre, e; /* .. */
|
|
uInt uiwork; /* for macros */
|
|
uInt sour; /* source 32-bit */
|
|
|
|
/* load source from storage; this is endian */
|
|
sour=UBTOUI(d32->bytes); /* 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. */
|
|
/* ------------------------------------------------------------------ */
|
|
uInt 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]|=(uByte)((e)>>4); \
|
|
(d)->bytes[1]|=(uByte)(((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
|