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-rw-r--r--libdecnumber/dpd/decimal128.c725
1 files changed, 472 insertions, 253 deletions
diff --git a/libdecnumber/dpd/decimal128.c b/libdecnumber/dpd/decimal128.c
index 92b4f618eff..0e32ceb181c 100644
--- a/libdecnumber/dpd/decimal128.c
+++ b/libdecnumber/dpd/decimal128.c
@@ -1,5 +1,5 @@
-/* Decimal 128-bit format module from the decNumber C Library.
- Copyright (C) 2005 Free Software Foundation, Inc.
+/* Decimal 128-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.
@@ -29,26 +29,37 @@
02110-1301, USA. */
/* ------------------------------------------------------------------ */
+/* Decimal 128-bit format module */
+/* ------------------------------------------------------------------ */
/* This module comprises the routines for decimal128 format numbers. */
-/* Conversions are supplied to and from decNumber and String. */
-/* */
-/* No arithmetic routines are included; decNumber provides these. */
-/* */
-/* Error handling is the same as decNumber (qv.). */
+/* 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 <string.h> /* [for memset/memcpy] */
+#include <stdio.h> /* [for printf] */
+
+#include "config.h" /* GCC definitions */
+#define DECNUMDIGITS 34 /* make decNumbers with space for 34 */
+#include "decNumber.h" /* base number library */
+#include "decNumberLocal.h" /* decNumber local types, etc. */
+#include "decimal128.h" /* our primary include */
-#define DECNUMDIGITS 34 /* we need decNumbers with space for 34 */
-#include "config.h"
-#include "decNumber.h" /* base number library */
-#include "decNumberLocal.h" /* decNumber local types, etc. */
-#include "decimal128.h" /* our primary include */
-#include "decUtility.h" /* utility routines */
+/* Utility routines and tables [in decimal64.c] */
+extern const uInt COMBEXP[32], COMBMSD[32];
+extern const uShort DPD2BIN[1024];
+extern const uShort BIN2DPD[1000]; /* [not used] */
+extern const uByte BIN2CHAR[4001];
+
+extern void decDigitsFromDPD(decNumber *, const uInt *, Int);
+extern void decDigitsToDPD(const decNumber *, uInt *, Int);
#if DECTRACE || DECCHECK
-void decimal128Show (const decimal128 *); /* for debug */
-void decNumberShow (const decNumber *); /* .. */
+void decimal128Show(const decimal128 *); /* for debug */
+extern void decNumberShow(const decNumber *); /* .. */
#endif
/* Useful macro */
@@ -56,292 +67,500 @@ void decNumberShow (const decNumber *); /* .. */
#define DEC_clear(d) memset(d, 0, sizeof(*d))
/* ------------------------------------------------------------------ */
-/* decimal128FromNumber -- convert decNumber to decimal128 */
-/* */
-/* ds is the target decimal128 */
-/* dn is the source number (assumed valid) */
-/* set is the context, used only for reporting errors */
-/* */
+/* decimal128FromNumber -- convert decNumber to decimal128 */
+/* */
+/* ds is the target decimal128 */
+/* 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 DECIMAL128_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. */
-/* */
+/* 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. */
/* ------------------------------------------------------------------ */
-decimal128 *
-decimal128FromNumber (decimal128 * d128, const decNumber * dn, decContext * set)
-{
- uInt status = 0; /* status accumulator */
- Int pad = 0; /* coefficient pad digits */
- decNumber dw; /* work */
- decContext dc; /* .. */
- uByte isneg = dn->bits & DECNEG; /* non-0 if original sign set */
- uInt comb, exp; /* work */
-
- /* If the number is finite, and has too many digits, or the exponent */
- /* could be out of range then we reduce the number under the */
- /* appropriate constraints */
- if (!(dn->bits & DECSPECIAL))
- { /* not a special value */
- Int ae = dn->exponent + dn->digits - 1; /* adjusted exponent */
- if (dn->digits > DECIMAL128_Pmax /* too many digits */
- || ae > DECIMAL128_Emax /* likely overflow */
- || ae < DECIMAL128_Emin)
- { /* likely underflow */
- decContextDefault (&dc, DEC_INIT_DECIMAL128); /* [no traps] */
- dc.round = set->round; /* use supplied rounding */
- decNumberPlus (&dw, dn, &dc); /* (round and check) */
- /* [this changes -0 to 0, but it will be restored below] */
- status |= dc.status; /* save status */
- dn = &dw; /* use the work number */
- }
- /* [this could have pushed number to Infinity or zero, so this */
- /* rounding must be done before we generate the decimal128] */
- }
+decimal128 * decimal128FromNumber(decimal128 *d128, const decNumber *dn,
+ decContext *set) {
+ uInt status=0; /* status accumulator */
+ Int ae; /* adjusted exponent */
+ decNumber dw; /* work */
+ decContext dc; /* .. */
+ uInt *pu; /* .. */
+ uInt comb, exp; /* .. */
+ uInt targar[4]={0,0,0,0}; /* target 128-bit */
+ #define targhi targar[3] /* name the word with the sign */
+ #define targmh targar[2] /* name the words */
+ #define targml targar[1] /* .. */
+ #define targlo targar[0] /* .. */
+
+ /* 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 */
+ /* decimal128] */
+ ae=dn->exponent+dn->digits-1; /* [0 if special] */
+ if (dn->digits>DECIMAL128_Pmax /* too many digits */
+ || ae>DECIMAL128_Emax /* likely overflow */
+ || ae<DECIMAL128_Emin) { /* likely underflow */
+ decContextDefault(&dc, DEC_INIT_DECIMAL128); /* [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 */
- DEC_clear (d128); /* clean the target */
- if (dn->bits & DECSPECIAL)
- { /* a special value */
- uByte top; /* work */
- if (dn->bits & DECINF)
- top = DECIMAL_Inf;
- else
- { /* sNaN or qNaN */
- if ((*dn->lsu != 0 || dn->digits > 1) /* non-zero coefficient */
- && (dn->digits < DECIMAL128_Pmax))
- { /* coefficient fits */
- decDensePackCoeff (dn, d128->bytes, sizeof (d128->bytes), 0);
- }
- if (dn->bits & DECNAN)
- top = DECIMAL_NaN;
- else
- top = DECIMAL_sNaN;
+ if (dn->bits&DECSPECIAL) { /* a special value */
+ if (dn->bits&DECINF) targhi=DECIMAL_Inf<<24;
+ else { /* sNaN or qNaN */
+ if ((*dn->lsu!=0 || dn->digits>1) /* non-zero coefficient */
+ && (dn->digits<DECIMAL128_Pmax)) { /* coefficient fits */
+ decDigitsToDPD(dn, targar, 0);
}
- d128->bytes[0] = top;
- }
- else if (decNumberIsZero (dn))
- { /* a zero */
+ if (dn->bits&DECNAN) targhi|=DECIMAL_NaN<<24;
+ else targhi|=DECIMAL_sNaN<<24;
+ } /* a NaN */
+ } /* special */
+
+ else { /* is finite */
+ if (decNumberIsZero(dn)) { /* is a zero */
/* set and clamp exponent */
- if (dn->exponent < -DECIMAL128_Bias)
- {
- exp = 0;
- status |= DEC_Clamped;
+ if (dn->exponent<-DECIMAL128_Bias) {
+ exp=0; /* low clamp */
+ status|=DEC_Clamped;
}
- else
- {
- exp = dn->exponent + DECIMAL128_Bias; /* bias exponent */
- if (exp > DECIMAL128_Ehigh)
- { /* top clamp */
- exp = DECIMAL128_Ehigh;
- status |= DEC_Clamped;
- }
- }
- comb = (exp >> 9) & 0x18; /* combination field */
- d128->bytes[0] = (uByte) (comb << 2);
- exp &= 0xfff; /* remaining exponent bits */
- decimal128SetExpCon (d128, exp);
- }
- else
- { /* non-zero finite number */
- uInt msd; /* work */
-
- /* we have a dn that fits, but it may need to be padded */
- exp = (uInt) (dn->exponent + DECIMAL128_Bias); /* bias exponent */
-
- if (exp > DECIMAL128_Ehigh)
- { /* fold-down case */
- pad = exp - DECIMAL128_Ehigh;
- exp = DECIMAL128_Ehigh; /* [to maximum] */
- status |= DEC_Clamped;
+ else {
+ exp=dn->exponent+DECIMAL128_Bias; /* bias exponent */
+ if (exp>DECIMAL128_Ehigh) { /* top clamp */
+ exp=DECIMAL128_Ehigh;
+ status|=DEC_Clamped;
+ }
}
+ comb=(exp>>9) & 0x18; /* msd=0, exp top 2 bits .. */
+ }
+ else { /* non-zero finite number */
+ uInt msd; /* work */
+ Int pad=0; /* coefficient pad digits */
- decDensePackCoeff (dn, d128->bytes, sizeof (d128->bytes), pad);
+ /* the dn is known to fit, but it may need to be padded */
+ exp=(uInt)(dn->exponent+DECIMAL128_Bias); /* bias exponent */
+ if (exp>DECIMAL128_Ehigh) { /* fold-down case */
+ pad=exp-DECIMAL128_Ehigh;
+ exp=DECIMAL128_Ehigh; /* [to maximum] */
+ status|=DEC_Clamped;
+ }
+ /* [fastpath for common case is not a win, here] */
+ decDigitsToDPD(dn, targar, pad);
/* save and clear the top digit */
- msd = ((unsigned) d128->bytes[1] << 2) & 0x0c; /* top 2 bits */
- msd |= ((unsigned) d128->bytes[2] >> 6); /* low 2 bits */
- d128->bytes[1] &= 0xfc;
- d128->bytes[2] &= 0x3f;
+ msd=targhi>>14;
+ targhi&=0x00003fff;
/* create the combination field */
- if (msd >= 8)
- comb = 0x18 | (msd & 0x01) | ((exp >> 11) & 0x06);
- else
- comb = (msd & 0x07) | ((exp >> 9) & 0x18);
- d128->bytes[0] = (uByte) (comb << 2);
- exp &= 0xfff; /* remaining exponent bits */
- decimal128SetExpCon (d128, exp);
- }
+ if (msd>=8) comb=0x18 | ((exp>>11) & 0x06) | (msd & 0x01);
+ else comb=((exp>>9) & 0x18) | msd;
+ }
+ targhi|=comb<<26; /* add combination field .. */
+ targhi|=(exp&0xfff)<<14; /* .. and exponent continuation */
+ } /* finite */
- if (isneg)
- decimal128SetSign (d128, 1);
- if (status != 0)
- decContextSetStatus (set, status); /* pass on status */
+ if (dn->bits&DECNEG) targhi|=0x80000000; /* add sign bit */
+ /* now write to storage; this is endian */
+ pu=(uInt *)d128->bytes; /* overlay */
+ if (DECLITEND) {
+ pu[0]=targlo; /* directly store the low int */
+ pu[1]=targml; /* then the mid-low */
+ pu[2]=targmh; /* then the mid-high */
+ pu[3]=targhi; /* then the high int */
+ }
+ else {
+ pu[0]=targhi; /* directly store the high int */
+ pu[1]=targmh; /* then the mid-high */
+ pu[2]=targml; /* then the mid-low */
+ pu[3]=targlo; /* then the low int */
+ }
+
+ if (status!=0) decContextSetStatus(set, status); /* pass on status */
/* decimal128Show(d128); */
return d128;
-}
+ } /* decimal128FromNumber */
/* ------------------------------------------------------------------ */
-/* decimal128ToNumber -- convert decimal128 to decNumber */
-/* d128 is the source decimal128 */
-/* dn is the target number, with appropriate space */
-/* No error is possible. */
+/* decimal128ToNumber -- convert decimal128 to decNumber */
+/* d128 is the source decimal128 */
+/* dn is the target number, with appropriate space */
+/* No error is possible. */
/* ------------------------------------------------------------------ */
-decNumber *
-decimal128ToNumber (const decimal128 * d128, decNumber * dn)
-{
- uInt msd; /* coefficient MSD */
- decimal128 wk; /* working copy, if needed */
- uInt top = d128->bytes[0] & 0x7f; /* top byte, less sign bit */
- decNumberZero (dn); /* clean target */
- /* set the sign if negative */
- if (decimal128Sign (d128))
- dn->bits = DECNEG;
-
- if (top >= 0x78)
- { /* is a special */
- if ((top & 0x7c) == (DECIMAL_Inf & 0x7c))
- dn->bits |= DECINF;
- else if ((top & 0x7e) == (DECIMAL_NaN & 0x7e))
- dn->bits |= DECNAN;
- else
- dn->bits |= DECSNAN;
- msd = 0; /* no top digit */
+decNumber * decimal128ToNumber(const decimal128 *d128, decNumber *dn) {
+ uInt msd; /* coefficient MSD */
+ uInt exp; /* exponent top two bits */
+ uInt comb; /* combination field */
+ const uInt *pu; /* work */
+ Int need; /* .. */
+ uInt sourar[4]; /* source 128-bit */
+ #define sourhi sourar[3] /* name the word with the sign */
+ #define sourmh sourar[2] /* and the mid-high word */
+ #define sourml sourar[1] /* and the mod-low word */
+ #define sourlo sourar[0] /* and the lowest word */
+
+ /* load source from storage; this is endian */
+ pu=(const uInt *)d128->bytes; /* overlay */
+ if (DECLITEND) {
+ sourlo=pu[0]; /* directly load the low int */
+ sourml=pu[1]; /* then the mid-low */
+ sourmh=pu[2]; /* then the mid-high */
+ sourhi=pu[3]; /* then the high int */
}
- else
- { /* have a finite number */
- uInt comb = top >> 2; /* combination field */
- uInt exp; /* exponent */
-
- if (comb >= 0x18)
- {
- msd = 8 + (comb & 0x01);
- exp = (comb & 0x06) << 11; /* MSBs */
- }
- else
- {
- msd = comb & 0x07;
- exp = (comb & 0x18) << 9;
- }
- dn->exponent = exp + decimal128ExpCon (d128) - DECIMAL128_Bias; /* remove bias */
+ else {
+ sourhi=pu[0]; /* directly load the high int */
+ sourmh=pu[1]; /* then the mid-high */
+ sourml=pu[2]; /* then the mid-low */
+ sourlo=pu[3]; /* then the low int */
}
- /* get the coefficient, unless infinite */
- if (!(dn->bits & DECINF))
- {
- Int bunches = DECIMAL128_Pmax / 3; /* coefficient full bunches to convert */
- Int odd = 0; /* assume MSD is 0 (no odd bunch) */
- if (msd != 0)
- { /* coefficient has leading non-0 digit */
- /* make a copy of the decimal128, with an extra bunch which has */
- /* the top digit ready for conversion */
- wk = *d128; /* take a copy */
- wk.bytes[0] = 0; /* clear all but coecon */
- wk.bytes[1] = 0; /* .. */
- wk.bytes[2] &= 0x3f; /* .. */
- wk.bytes[1] |= (msd >> 2); /* and prefix MSD */
- wk.bytes[2] |= (msd << 6); /* .. */
- odd++; /* indicate the extra */
- d128 = &wk; /* use the work copy */
- }
- decDenseUnpackCoeff (d128->bytes, sizeof (d128->bytes), dn, bunches,
- odd);
+ comb=(sourhi>>26)&0x1f; /* combination field */
+
+ decNumberZero(dn); /* clean number */
+ if (sourhi&0x80000000) dn->bits=DECNEG; /* set sign if negative */
+
+ msd=COMBMSD[comb]; /* decode the combination field */
+ exp=COMBEXP[comb]; /* .. */
+
+ if (exp==3) { /* is a special */
+ if (msd==0) {
+ dn->bits|=DECINF;
+ return dn; /* no coefficient needed */
+ }
+ else if (sourhi&0x02000000) dn->bits|=DECSNAN;
+ else dn->bits|=DECNAN;
+ msd=0; /* no top digit */
+ }
+ else { /* is a finite number */
+ dn->exponent=(exp<<12)+((sourhi>>14)&0xfff)-DECIMAL128_Bias; /* unbiased */
}
+ /* get the coefficient */
+ sourhi&=0x00003fff; /* clean coefficient continuation */
+ if (msd) { /* non-zero msd */
+ sourhi|=msd<<14; /* prefix to coefficient */
+ need=12; /* process 12 declets */
+ }
+ else { /* msd=0 */
+ if (sourhi) need=11; /* declets to process */
+ else if (sourmh) need=10;
+ else if (sourml) need=7;
+ else if (sourlo) need=4;
+ else return dn; /* easy: coefficient is 0 */
+ } /*msd=0 */
+
+ decDigitsFromDPD(dn, sourar, need); /* process declets */
/* decNumberShow(dn); */
return dn;
-}
+ } /* decimal128ToNumber */
/* ------------------------------------------------------------------ */
-/* to-scientific-string -- conversion to numeric string */
-/* to-engineering-string -- conversion to numeric string */
-/* */
-/* decimal128ToString(d128, string); */
-/* decimal128ToEngString(d128, string); */
-/* */
-/* d128 is the decimal128 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. */
+/* to-scientific-string -- conversion to numeric string */
+/* to-engineering-string -- conversion to numeric string */
+/* */
+/* decimal128ToString(d128, string); */
+/* decimal128ToEngString(d128, string); */
+/* */
+/* d128 is the decimal128 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 *
-decimal128ToString (const decimal128 * d128, char *string)
-{
- decNumber dn; /* work */
- decimal128ToNumber (d128, &dn);
- decNumberToString (&dn, string);
+char * decimal128ToEngString(const decimal128 *d128, char *string){
+ decNumber dn; /* work */
+ decimal128ToNumber(d128, &dn);
+ decNumberToEngString(&dn, string);
return string;
-}
-
-char *
-decimal128ToEngString (const decimal128 * d128, char *string)
-{
- decNumber dn; /* work */
- decimal128ToNumber (d128, &dn);
- decNumberToEngString (&dn, string);
+ } /* decimal128ToEngString */
+
+char * decimal128ToString(const decimal128 *d128, char *string){
+ uInt msd; /* coefficient MSD */
+ Int exp; /* exponent top two bits or full */
+ uInt comb; /* combination field */
+ char *cstart; /* coefficient start */
+ char *c; /* output pointer in string */
+ const uInt *pu; /* work */
+ char *s, *t; /* .. (source, target) */
+ Int dpd; /* .. */
+ Int pre, e; /* .. */
+ const uByte *u; /* .. */
+
+ uInt sourar[4]; /* source 128-bit */
+ #define sourhi sourar[3] /* name the word with the sign */
+ #define sourmh sourar[2] /* and the mid-high word */
+ #define sourml sourar[1] /* and the mod-low word */
+ #define sourlo sourar[0] /* and the lowest word */
+
+ /* load source from storage; this is endian */
+ pu=(const uInt *)d128->bytes; /* overlay */
+ if (DECLITEND) {
+ sourlo=pu[0]; /* directly load the low int */
+ sourml=pu[1]; /* then the mid-low */
+ sourmh=pu[2]; /* then the mid-high */
+ sourhi=pu[3]; /* then the high int */
+ }
+ else {
+ sourhi=pu[0]; /* directly load the high int */
+ sourmh=pu[1]; /* then the mid-high */
+ sourml=pu[2]; /* then the mid-low */
+ sourlo=pu[3]; /* then the low int */
+ }
+
+ c=string; /* where result will go */
+ if (((Int)sourhi)<0) *c++='-'; /* handle sign */
+
+ comb=(sourhi>>26)&0x1f; /* combination field */
+ msd=COMBMSD[comb]; /* decode the combination field */
+ exp=COMBEXP[comb]; /* .. */
+
+ if (exp==3) {
+ if (msd==0) { /* infinity */
+ strcpy(c, "Inf");
+ strcpy(c+3, "inity");
+ return string; /* easy */
+ }
+ if (sourhi&0x02000000) *c++='s'; /* sNaN */
+ strcpy(c, "NaN"); /* complete word */
+ c+=3; /* step past */
+ if (sourlo==0 && sourml==0 && sourmh==0
+ && (sourhi&0x0003ffff)==0) return string; /* zero payload */
+ /* otherwise drop through to add integer; set correct exp */
+ exp=0; msd=0; /* setup for following code */
+ }
+ else exp=(exp<<12)+((sourhi>>14)&0xfff)-DECIMAL128_Bias; /* unbiased */
+
+ /* convert 34 digits of significand to characters */
+ cstart=c; /* save start of coefficient */
+ if (msd) *c++='0'+(char)msd; /* non-zero most significant digit */
+
+ /* Now decode the declets. After extracting each one, it is */
+ /* decoded to binary and then to a 4-char sequence by table lookup; */
+ /* the 4-chars are a 1-char length (significant digits, except 000 */
+ /* has length 0). This allows us to left-align the first declet */
+ /* with non-zero content, then remaining ones are full 3-char */
+ /* length. We use fixed-length memcpys because variable-length */
+ /* causes a subroutine call in GCC. (These are length 4 for speed */
+ /* and are safe because the array has an extra terminator byte.) */
+ #define dpd2char u=&BIN2CHAR[DPD2BIN[dpd]*4]; \
+ if (c!=cstart) {memcpy(c, u+1, 4); c+=3;} \
+ else if (*u) {memcpy(c, u+4-*u, 4); c+=*u;}
+ dpd=(sourhi>>4)&0x3ff; /* declet 1 */
+ dpd2char;
+ dpd=((sourhi&0xf)<<6) | (sourmh>>26); /* declet 2 */
+ dpd2char;
+ dpd=(sourmh>>16)&0x3ff; /* declet 3 */
+ dpd2char;
+ dpd=(sourmh>>6)&0x3ff; /* declet 4 */
+ dpd2char;
+ dpd=((sourmh&0x3f)<<4) | (sourml>>28); /* declet 5 */
+ dpd2char;
+ dpd=(sourml>>18)&0x3ff; /* declet 6 */
+ dpd2char;
+ dpd=(sourml>>8)&0x3ff; /* declet 7 */
+ dpd2char;
+ dpd=((sourml&0xff)<<2) | (sourlo>>30); /* declet 8 */
+ dpd2char;
+ dpd=(sourlo>>20)&0x3ff; /* declet 9 */
+ dpd2char;
+ dpd=(sourlo>>10)&0x3ff; /* declet 10 */
+ dpd2char;
+ dpd=(sourlo)&0x3ff; /* declet 11 */
+ 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 4 digits */
+ if (e!=0) {
+ *c++='E'; /* starts with E */
+ *c++='+'; /* assume positive */
+ if (e<0) {
+ *(c-1)='-'; /* oops, need '-' */
+ e=-e; /* uInt, please */
+ }
+ if (e<1000) { /* 3 (or fewer) digits case */
+ u=&BIN2CHAR[e*4]; /* -> length byte */
+ memcpy(c, u+4-*u, 4); /* copy fixed 4 characters [is safe] */
+ c+=*u; /* bump pointer appropriately */
+ }
+ else { /* 4-digits */
+ Int thou=((e>>3)*1049)>>17; /* e/1000 */
+ Int rem=e-(1000*thou); /* e%1000 */
+ *c++='0'+(char)thou;
+ u=&BIN2CHAR[rem*4]; /* -> length byte */
+ memcpy(c, u+1, 4); /* copy fixed 3+1 characters [is safe] */
+ c+=3; /* bump pointer, always 3 digits */
+ }
+ }
+ *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;
-}
+ } /* decimal128ToString */
/* ------------------------------------------------------------------ */
-/* to-number -- conversion from numeric string */
-/* */
-/* decimal128FromString(result, string, set); */
-/* */
+/* to-number -- conversion from numeric string */
+/* */
+/* decimal128FromString(result, string, set); */
+/* */
/* result is the decimal128 format number which gets the result of */
-/* the conversion */
+/* the conversion */
/* *string is the character string which should contain a valid */
-/* number (which may be a special value) */
-/* set is the context */
-/* */
+/* 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 decimal128 NaN. */
/* ------------------------------------------------------------------ */
-decimal128 *
-decimal128FromString (decimal128 * result, const char *string, decContext * set)
-{
- decContext dc; /* work */
- decNumber dn; /* .. */
-
- decContextDefault (&dc, DEC_INIT_DECIMAL128); /* no traps, please */
- dc.round = set->round; /* use supplied rounding */
-
- decNumberFromString (&dn, string, &dc); /* will round if needed */
- decimal128FromNumber (result, &dn, &dc);
- if (dc.status != 0)
- { /* something happened */
- decContextSetStatus (set, dc.status); /* .. pass it on */
+decimal128 * decimal128FromString(decimal128 *result, const char *string,
+ decContext *set) {
+ decContext dc; /* work */
+ decNumber dn; /* .. */
+
+ decContextDefault(&dc, DEC_INIT_DECIMAL128); /* no traps, please */
+ dc.round=set->round; /* use supplied rounding */
+
+ decNumberFromString(&dn, string, &dc); /* will round if needed */
+ decimal128FromNumber(result, &dn, &dc);
+ if (dc.status!=0) { /* something happened */
+ decContextSetStatus(set, dc.status); /* .. pass it on */
}
return result;
-}
+ } /* decimal128FromString */
+
+/* ------------------------------------------------------------------ */
+/* decimal128IsCanonical -- test whether encoding is canonical */
+/* d128 is the source decimal128 */
+/* returns 1 if the encoding of d128 is canonical, 0 otherwise */
+/* No error is possible. */
+/* ------------------------------------------------------------------ */
+uint32_t decimal128IsCanonical(const decimal128 *d128) {
+ decNumber dn; /* work */
+ decimal128 canon; /* .. */
+ decContext dc; /* .. */
+ decContextDefault(&dc, DEC_INIT_DECIMAL128);
+ decimal128ToNumber(d128, &dn);
+ decimal128FromNumber(&canon, &dn, &dc);/* canon will now be canonical */
+ return memcmp(d128, &canon, DECIMAL128_Bytes)==0;
+ } /* decimal128IsCanonical */
+/* ------------------------------------------------------------------ */
+/* decimal128Canonical -- copy an encoding, ensuring it is canonical */
+/* d128 is the source decimal128 */
+/* result is the target (may be the same decimal128) */
+/* returns result */
+/* No error is possible. */
+/* ------------------------------------------------------------------ */
+decimal128 * decimal128Canonical(decimal128 *result, const decimal128 *d128) {
+ decNumber dn; /* work */
+ decContext dc; /* .. */
+ decContextDefault(&dc, DEC_INIT_DECIMAL128);
+ decimal128ToNumber(d128, &dn);
+ decimal128FromNumber(result, &dn, &dc);/* result will now be canonical */
+ return result;
+ } /* decimal128Canonical */
#if DECTRACE || DECCHECK
+/* Macros for accessing decimal128 fields. These assume the argument
+ is a reference (pointer) to the decimal128 structure, and the
+ decimal128 is in network byte order (big-endian) */
+/* Get sign */
+#define decimal128Sign(d) ((unsigned)(d)->bytes[0]>>7)
+
+/* Get combination field */
+#define decimal128Comb(d) (((d)->bytes[0] & 0x7c)>>2)
+
+/* Get exponent continuation [does not remove bias] */
+#define decimal128ExpCon(d) ((((d)->bytes[0] & 0x03)<<10) \
+ | ((unsigned)(d)->bytes[1]<<2) \
+ | ((unsigned)(d)->bytes[2]>>6))
+
+/* Set sign [this assumes sign previously 0] */
+#define decimal128SetSign(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 decimal128SetExpCon(d, e) { \
+ (d)->bytes[0]|=(uint8_t)((e)>>10); \
+ (d)->bytes[1] =(uint8_t)(((e)&0x3fc)>>2); \
+ (d)->bytes[2]|=(uint8_t)(((e)&0x03)<<6);}
+
/* ------------------------------------------------------------------ */
-/* decimal128Show -- display a single in hexadecimal [debug aid] */
-/* d128 -- the number to show */
+/* decimal128Show -- display a decimal128 in hexadecimal [debug aid] */
+/* d128 -- the number to show */
/* ------------------------------------------------------------------ */
/* Also shows sign/cob/expconfields extracted */
-void
-decimal128Show (const decimal128 * d128)
-{
- char buf[DECIMAL128_Bytes * 2 + 1];
- Int i, j;
- j = 0;
- for (i = 0; i < DECIMAL128_Bytes; i++)
- {
- sprintf (&buf[j], "%02x", d128->bytes[i]);
- j = j + 2;
+void decimal128Show(const decimal128 *d128) {
+ char buf[DECIMAL128_Bytes*2+1];
+ Int i, j=0;
+
+ if (DECLITEND) {
+ for (i=0; i<DECIMAL128_Bytes; i++, j+=2) {
+ sprintf(&buf[j], "%02x", d128->bytes[15-i]);
+ }
+ printf(" D128> %s [S:%d Cb:%02x Ec:%02x] LittleEndian\n", buf,
+ d128->bytes[15]>>7, (d128->bytes[15]>>2)&0x1f,
+ ((d128->bytes[15]&0x3)<<10)|(d128->bytes[14]<<2)|
+ (d128->bytes[13]>>6));
+ }
+ else {
+ for (i=0; i<DECIMAL128_Bytes; i++, j+=2) {
+ sprintf(&buf[j], "%02x", d128->bytes[i]);
+ }
+ printf(" D128> %s [S:%d Cb:%02x Ec:%02x] BigEndian\n", buf,
+ decimal128Sign(d128), decimal128Comb(d128),
+ decimal128ExpCon(d128));
}
- printf (" D128> %s [S:%d Cb:%02x E:%d]\n", buf,
- decimal128Sign (d128), decimal128Comb (d128),
- decimal128ExpCon (d128));
-}
+ } /* decimal128Show */
#endif