its decimal conversion functions can be used if desired (see
real.h).
-The first part of this file interfaces gcc to ieee.c, which is a
-floating point arithmetic suite that was not written with gcc in
-mind. The interface is followed by ieee.c itself and related
-items. Avoid changing ieee.c unless you have suitable test
-programs available. A special version of the PARANOIA floating
-point arithmetic tester, modified for this purpose, can be found
-on usc.edu : /pub/C-numanal/ieeetest.zoo. Some tutorial
-information on ieee.c is given in my book: S. L. Moshier,
-_Methods and Programs for Mathematical Functions_, Prentice-Hall
-or Simon & Schuster Int'l, 1989. A library of XFmode elementary
-transcendental functions can be obtained by ftp from
-research.att.com: netlib/cephes/ldouble.shar.Z */
+The first part of this file interfaces gcc to a floating point
+arithmetic suite that was not written with gcc in mind. Avoid
+changing the low-level arithmetic routines unless you have suitable
+test programs available. A special version of the PARANOIA floating
+point arithmetic tester, modified for this purpose, can be found on
+usc.edu: /pub/C-numanal/ieeetest.zoo. Other tests, and libraries of
+XFmode and TFmode transcendental functions, can be obtained by ftp from
+netlib.att.com: netlib/cephes. */
\f
/* Type of computer arithmetic.
Only one of DEC, IBM, IEEE, or UNK should get defined.
- `IEEE', when FLOAT_WORDS_BIG_ENDIAN is non-zero, refers generically
+ `IEEE', when REAL_WORDS_BIG_ENDIAN is non-zero, refers generically
to big-endian IEEE floating-point data structure. This definition
should work in SFmode `float' type and DFmode `double' type on
virtually all big-endian IEEE machines. If LONG_DOUBLE_TYPE_SIZE
XFmode (`long double' type) data structure used by the Motorola
680x0 series processors.
- `IEEE', when FLOAT_WORDS_BIG_ENDIAN is zero, refers generally to
+ `IEEE', when REAL_WORDS_BIG_ENDIAN is zero, refers generally to
little-endian IEEE machines. In this case, if LONG_DOUBLE_TYPE_SIZE
has been defined to be 96, then IEEE also invokes the particular
XFmode `long double' data structure used by the Intel 80x86 series
#endif /* not IBM */
#endif /* not VAX */
+#define REAL_WORDS_BIG_ENDIAN FLOAT_WORDS_BIG_ENDIAN
+
#else
/* REAL_ARITHMETIC not defined means that the *host's* data
structure will be used. It may differ by endian-ness from the
#endif /* not IBM */
#endif /* not VAX */
+#define REAL_WORDS_BIG_ENDIAN HOST_FLOAT_WORDS_BIG_ENDIAN
+
#endif /* REAL_ARITHMETIC not defined */
/* Define INFINITY for support of infinity.
#define GET_REAL(r,e) \
do { \
- if (HOST_FLOAT_WORDS_BIG_ENDIAN == FLOAT_WORDS_BIG_ENDIAN) \
+ if (HOST_FLOAT_WORDS_BIG_ENDIAN == REAL_WORDS_BIG_ENDIAN) \
e53toe ((unsigned EMUSHORT*) (r), (e)); \
else \
{ \
#define PUT_REAL(e,r) \
do { \
- if (HOST_FLOAT_WORDS_BIG_ENDIAN == FLOAT_WORDS_BIG_ENDIAN) \
+ if (HOST_FLOAT_WORDS_BIG_ENDIAN == REAL_WORDS_BIG_ENDIAN) \
etoe53 ((e), (unsigned EMUSHORT *) (r)); \
else \
{ \
{
unsigned long th, t;
- if (FLOAT_WORDS_BIG_ENDIAN)
+ if (REAL_WORDS_BIG_ENDIAN)
{
switch (mode)
{
#endif
}
-
/* Check whether a REAL_VALUE_TYPE item is a NaN. */
int
}
\f
-/* Target values are arrays of host longs. A long is guaranteed
- to be at least 32 bits wide. */
+/* The following routines convert REAL_VALUE_TYPE to the various floating
+ point formats that are meaningful to supported computers.
+
+ The results are returned in 32-bit pieces, each piece stored in a `long'.
+ This is so they can be printed by statements like
+
+ fprintf (file, "%lx, %lx", L[0], L[1]);
+
+ that will work on both narrow- and wide-word host computers. */
-/* 128-bit long double */
+/* Convert R to a 128-bit long double precision value. The output array L
+ contains four 32-bit pieces of the result, in the order they would appear
+ in memory. */
void
etartdouble (r, l)
endian (e, l, TFmode);
}
-/* 80-bit long double */
+/* Convert R to a double extended precision value. The output array L
+ contains three 32-bit pieces of the result, in the order they would
+ appear in memory. */
void
etarldouble (r, l)
endian (e, l, XFmode);
}
+/* Convert R to a double precision value. The output array L contains two
+ 32-bit pieces of the result, in the order they would appear in memory. */
+
void
etardouble (r, l)
REAL_VALUE_TYPE r;
endian (e, l, DFmode);
}
+/* Convert R to a single precision float value stored in the least-significant
+ bits of a `long'. */
+
long
etarsingle (r)
REAL_VALUE_TYPE r;
return ((long) l);
}
+/* Convert X to a decimal ASCII string S for output to an assembly
+ language file. Note, there is no standard way to spell infinity or
+ a NaN, so these values may require special treatment in the tm.h
+ macros. */
+
void
ereal_to_decimal (x, s)
REAL_VALUE_TYPE x;
etoasc (e, s, 20);
}
+/* Compare X and Y. Return 1 if X > Y, 0 if X == Y, -1 if X < Y,
+ or -2 if either is a NaN. */
+
int
ereal_cmp (x, y)
REAL_VALUE_TYPE x, y;
return (ecmp (ex, ey));
}
+/* Return 1 if the sign bit of X is set, else return 0. */
+
int
ereal_isneg (x)
REAL_VALUE_TYPE x;
short integers. The arguments of the routines are pointers to
the arrays.
- External e type data structure, simulates Intel 8087 chip
+ External e type data structure, similar to Intel 8087 chip
temporary real format but possibly with a larger significand:
NE-1 significand words (least significant word first,
top bit is the sign)
- Internal data structure of a number (a "word" is 16 bits):
+ Internal exploded e-type data structure of a number (a "word" is 16 bits):
ei[0] sign word (0 for positive, 0xffff for negative)
ei[1] biased exponent (value = EXONE for the number 1.0)
- Routines for external format numbers
+ Routines for external format e-type numbers
asctoe (string, e) ASCII string to extended double e type
asctoe64 (string, &d) ASCII string to long double
eisnan (e) 1 if e is a NaN
- Routines for internal format numbers
+ Routines for internal format exploded e-type numbers
eaddm (ai, bi) add significands, bi = bi + ai
ecleaz (ei) ei = 0
For computers, such as IBM PC, that follow the IEEE
Standard for Binary Floating Point Arithmetic (ANSI/IEEE
- Std 754-1985), the symbol IBMPC or MIEEE should be defined.
+ Std 754-1985), the symbol IEEE should be defined.
These numbers have 53-bit significands. In this mode, constants
are provided as arrays of hexadecimal 16 bit integers.
- [This has been changed to instead check the preprocessor macros IEEE
- and FLOAT_WORDS_BIG_ENDIAN].
+ The endian-ness of generated values is controlled by
+ REAL_WORDS_BIG_ENDIAN.
To accommodate other types of computer arithmetic, all
constants are also provided in a normal decimal radix
{0xc4c6, 0xc234, 0020550, 0155242, 0144417, 0040000,};
#endif
-
-
/* Control register for rounding precision.
This can be set to 113 (if NE=10), 80 (if NE=6), 64, 56, 53, or 24 bits. */
int rndprc = NBITS;
extern int rndprc;
-/* Clear out entire external format number. */
+/* Clear out entire e-type number X. */
static void
eclear (x)
*x++ = 0;
}
-
-
-/* Move external format number from a to b. */
+/* Move e-type number from A to B. */
static void
emov (a, b)
}
-/* Absolute value of external format number. */
+/* Absolute value of e-type X. */
static void
eabs (x)
x[NE - 1] &= 0x7fff;
}
-/* Negate external format number. */
+/* Negate the e-type number X. */
static void
eneg (x)
x[NE - 1] ^= 0x8000; /* Toggle the sign bit */
}
-
-
-/* Return 1 if sign bit of external format number is nonzero, else zero. */
+/* Return 1 if sign bit of e-type number X is nonzero, else zero. */
static int
eisneg (x)
return (0);
}
-
-/* Return 1 if external format number is infinity, else return zero. */
+/* Return 1 if e-type number X is infinity, else return zero. */
static int
eisinf (x)
return (0);
}
-
/* Check if e-type number is not a number. The bit pattern is one that we
defined, so we know for sure how to detect it. */
return (0);
}
-/* Fill external format number with infinity pattern (IEEE)
+/* Fill e-type number X with infinity pattern (IEEE)
or largest possible number (non-IEEE). */
static void
#endif
}
-
/* Output an e-type NaN.
This generates Intel's quiet NaN pattern for extended real.
The exponent is 7fff, the leading mantissa word is c000. */
*x = (sign << 15) | 0x7fff;
}
-
-/* Move in external format number, converting it to internal format. */
+/* Move in an e-type number A, converting it to exploded e-type B. */
static void
emovi (a, b)
*q = 0;
}
-
-/* Move internal format number out, converting it to external format. */
+/* Move out exploded e-type number A, converting it to e type B. */
static void
emovo (a, b)
*q-- = *p++;
}
-/* Clear out internal format number. */
+/* Clear out exploded e-type number XI. */
static void
ecleaz (xi)
*xi++ = 0;
}
-
-/* Same, but don't touch the sign. */
+/* Clear out exploded e-type XI, but don't touch the sign. */
static void
ecleazs (xi)
*xi++ = 0;
}
-
-
-/* Move internal format number from a to b. */
+/* Move exploded e-type number from A to B. */
static void
emovz (a, b)
*b = 0;
}
-/* Generate internal format NaN.
+/* Generate exploded e-type NaN.
The explicit pattern for this is maximum exponent and
top two significant bits set. */
x[M + 1] = 0xc000;
}
-/* Return nonzero if internal format number is a NaN. */
+/* Return nonzero if exploded e-type X is a NaN. */
static int
eiisnan (x)
return (0);
}
-/* Return nonzero if sign of internal format number is nonzero. */
+/* Return nonzero if sign of exploded e-type X is nonzero. */
static int
eiisneg (x)
return x[0] != 0;
}
-/* Fill internal format number with infinity pattern.
+/* Fill exploded e-type X with infinity pattern.
This has maximum exponent and significand all zeros. */
static void
x[E] = 0x7fff;
}
-/* Return nonzero if internal format number is infinite. */
+/* Return nonzero if exploded e-type X is infinite. */
static int
eiisinf (x)
}
-/* Compare significands of numbers in internal format.
+/* Compare significands of numbers in internal exploded e-type format.
Guard words are included in the comparison.
Returns +1 if a > b
return (-1);
}
-
-/* Shift significand down by 1 bit. */
+/* Shift significand of exploded e-type X down by 1 bit. */
static void
eshdn1 (x)
}
}
-
-
-/* Shift significand up by 1 bit. */
+/* Shift significand of exploded e-type X up by 1 bit. */
static void
eshup1 (x)
}
-/* Shift significand down by 8 bits. */
+/* Shift significand of exploded e-type X down by 8 bits. */
static void
eshdn8 (x)
}
}
-/* Shift significand up by 8 bits. */
+/* Shift significand of exploded e-type X up by 8 bits. */
static void
eshup8 (x)
}
}
-/* Shift significand up by 16 bits. */
+/* Shift significand of exploded e-type X up by 16 bits. */
static void
eshup6 (x)
*p = 0;
}
-/* Shift significand down by 16 bits. */
+/* Shift significand of exploded e-type X down by 16 bits. */
static void
eshdn6 (x)
*(--p) = 0;
}
-\f
-/* Add significands. x + y replaces y. */
+
+/* Add significands of exploded e-type X and Y. X + Y replaces Y. */
static void
eaddm (x, y)
}
}
-/* Subtract significands. y - x replaces y. */
+/* Subtract significands of exploded e-type X and Y. Y - X replaces Y. */
static void
esubm (x, y)
#else
-/* Radix 65536 versions of multiply and divide */
-
+/* Radix 65536 versions of multiply and divide. */
-/* Multiply significand of e-type number b
- by 16-bit quantity a, e-type result to c. */
+/* Multiply significand of e-type number B
+ by 16-bit quantity A, return e-type result to C. */
static void
m16m (a, b, c)
unsigned int a;
- unsigned short b[], c[];
+ unsigned EMUSHORT b[], c[];
{
- register unsigned short *pp;
- register unsigned long carry;
- unsigned short *ps;
- unsigned short p[NI];
- unsigned long aa, m;
+ register unsigned EMUSHORT *pp;
+ register unsigned EMULONG carry;
+ unsigned EMUSHORT *ps;
+ unsigned EMUSHORT p[NI];
+ unsigned EMULONG aa, m;
int i;
aa = a;
}
else
{
- m = (unsigned long) aa * *ps--;
+ m = (unsigned EMULONG) aa * *ps--;
carry = (m & 0xffff) + *pp;
- *pp-- = (unsigned short)carry;
+ *pp-- = (unsigned EMUSHORT)carry;
carry = (carry >> 16) + (m >> 16) + *pp;
- *pp = (unsigned short)carry;
+ *pp = (unsigned EMUSHORT)carry;
*(pp-1) = carry >> 16;
}
}
c[i] = p[i];
}
-
-/* Divide significands. Neither the numerator nor the denominator
- is permitted to have its high guard word nonzero. */
+/* Divide significands of exploded e-types NUM / DEN. Neither the
+ numerator NUM nor the denominator DEN is permitted to have its high guard
+ word nonzero. */
static int
edivm (den, num)
- unsigned short den[], num[];
+ unsigned EMUSHORT den[], num[];
{
int i;
- register unsigned short *p;
- unsigned long tnum;
- unsigned short j, tdenm, tquot;
- unsigned short tprod[NI+1];
+ register unsigned EMUSHORT *p;
+ unsigned EMULONG tnum;
+ unsigned EMUSHORT j, tdenm, tquot;
+ unsigned EMUSHORT tprod[NI+1];
p = &equot[0];
*p++ = num[0];
for (i=M; i<NI; i++)
{
/* Find trial quotient digit (the radix is 65536). */
- tnum = (((unsigned long) num[M]) << 16) + num[M+1];
+ tnum = (((unsigned EMULONG) num[M]) << 16) + num[M+1];
/* Do not execute the divide instruction if it will overflow. */
if ((tdenm * 0xffffL) < tnum)
return ((int)j);
}
+/* Multiply significands of exploded e-type A and B, result in B. */
-
-/* Multiply significands */
static int
emulm (a, b)
- unsigned short a[], b[];
+ unsigned EMUSHORT a[], b[];
{
- unsigned short *p, *q;
- unsigned short pprod[NI];
- unsigned short j;
+ unsigned EMUSHORT *p, *q;
+ unsigned EMUSHORT pprod[NI];
+ unsigned EMUSHORT j;
int i;
equot[0] = b[0];
/* Normalize and round off.
- The internal format number to be rounded is "s".
- Input "lost" indicates whether or not the number is exact.
- This is the so-called sticky bit.
+ The internal format number to be rounded is S.
+ Input LOST is 0 if the value is exact. This is the so-called sticky bit.
- Input "subflg" indicates whether the number was obtained
- by a subtraction operation. In that case if lost is nonzero
+ Input SUBFLG indicates whether the number was obtained
+ by a subtraction operation. In that case if LOST is nonzero
then the number is slightly smaller than indicated.
- Input "exp" is the biased exponent, which may be negative.
- the exponent field of "s" is ignored but is replaced by
- "exp" as adjusted by normalization and rounding.
+ Input EXP is the biased exponent, which may be negative.
+ the exponent field of S is ignored but is replaced by
+ EXP as adjusted by normalization and rounding.
- Input "rcntrl" is the rounding control.
+ Input RCNTRL is the rounding control. If it is nonzero, the
+ returned value will be rounded to RNDPRC bits.
For future reference: In order for emdnorm to round off denormal
significands at the right point, the input exponent must be
s[1] = (unsigned EMUSHORT) exp;
}
-
-
-/* Subtract external format numbers. */
+/* Subtract. C = B - A, all e type numbers. */
static int subflg = 0;
eadd1 (a, b, c);
}
-
-/* Add. */
+/* Add. C = A + B, all e type. */
static void
eadd (a, b, c)
eadd1 (a, b, c);
}
+/* Arithmetic common to both addition and subtraction. */
+
static void
eadd1 (a, b, c)
unsigned EMUSHORT *a, *b, *c;
emovo (bi, c);
}
-
-
-/* Divide. */
+/* Divide: C = B/A, all e type. */
static void
ediv (a, b, c)
emovo (bi, c);
}
-
-
-/* Multiply. */
+/* Multiply e-types A and B, return e-type product C. */
static void
emul (a, b, c)
emovo (bi, c);
}
-
-
-
-/* Convert IEEE double precision to e type. */
+/* Convert double precision PE to e-type Y. */
static void
e53toe (pe, y)
{
#ifdef DEC
- dectoe (pe, y); /* see etodec.c */
+ dectoe (pe, y);
#else
#ifdef IBM
e = pe;
denorm = 0; /* flag if denormalized number */
ecleaz (yy);
- if (! FLOAT_WORDS_BIG_ENDIAN)
+ if (! REAL_WORDS_BIG_ENDIAN)
e += 3;
r = *e;
yy[0] = 0;
if (r == 0x7ff0)
{
#ifdef NANS
- if (! FLOAT_WORDS_BIG_ENDIAN)
+ if (! REAL_WORDS_BIG_ENDIAN)
{
if (((pe[3] & 0xf) != 0) || (pe[2] != 0)
|| (pe[1] != 0) || (pe[0] != 0))
yy[E] = r;
p = &yy[M + 1];
#ifdef IEEE
- if (! FLOAT_WORDS_BIG_ENDIAN)
+ if (! REAL_WORDS_BIG_ENDIAN)
{
*p++ = *(--e);
*p++ = *(--e);
#endif /* not DEC */
}
+/* Convert double extended precision float PE to e type Y. */
+
static void
e64toe (pe, y)
unsigned EMUSHORT *pe, *y;
*p-- = *e++;
#endif
#ifdef IEEE
- if (! FLOAT_WORDS_BIG_ENDIAN)
+ if (! REAL_WORDS_BIG_ENDIAN)
{
for (i = 0; i < 5; i++)
*p++ = *e++;
if (*p == 0x7fff)
{
#ifdef NANS
- if (! FLOAT_WORDS_BIG_ENDIAN)
+ if (! REAL_WORDS_BIG_ENDIAN)
{
for (i = 0; i < 4; i++)
{
*q++ = *p++;
}
+/* Convert 128-bit long double precision float PE to e type Y. */
static void
e113toe (pe, y)
denorm = 0;
ecleaz (yy);
#ifdef IEEE
- if (! FLOAT_WORDS_BIG_ENDIAN)
+ if (! REAL_WORDS_BIG_ENDIAN)
e += 7;
#endif
r = *e;
if (r == 0x7fff)
{
#ifdef NANS
- if (! FLOAT_WORDS_BIG_ENDIAN)
+ if (! REAL_WORDS_BIG_ENDIAN)
{
for (i = 0; i < 7; i++)
{
yy[E] = r;
p = &yy[M + 1];
#ifdef IEEE
- if (! FLOAT_WORDS_BIG_ENDIAN)
+ if (! REAL_WORDS_BIG_ENDIAN)
{
for (i = 0; i < 7; i++)
*p++ = *(--e);
emovo (yy, y);
}
-
-/* Convert IEEE single precision to e type. */
+/* Convert single precision float PE to e type Y. */
static void
e24toe (pe, y)
denorm = 0; /* flag if denormalized number */
ecleaz (yy);
#ifdef IEEE
- if (! FLOAT_WORDS_BIG_ENDIAN)
+ if (! REAL_WORDS_BIG_ENDIAN)
e += 1;
#endif
#ifdef DEC
if (r == 0x7f80)
{
#ifdef NANS
- if (FLOAT_WORDS_BIG_ENDIAN)
+ if (REAL_WORDS_BIG_ENDIAN)
{
if (((pe[0] & 0x7f) != 0) || (pe[1] != 0))
{
*p++ = *(--e);
#endif
#ifdef IEEE
- if (! FLOAT_WORDS_BIG_ENDIAN)
+ if (! REAL_WORDS_BIG_ENDIAN)
*p++ = *(--e);
else
{
#endif /* not IBM */
}
+/* Convert e-type X to IEEE 128-bit long double format E. */
static void
etoe113 (x, e)
toe113 (xi, e);
}
-/* Move out internal format to ieee long double */
+/* Convert exploded e-type X, that has already been rounded to
+ 113-bit precision, to IEEE 128-bit long double format Y. */
static void
toe113 (a, b)
}
#endif
p = a;
- if (FLOAT_WORDS_BIG_ENDIAN)
+ if (REAL_WORDS_BIG_ENDIAN)
q = b;
else
q = b + 7; /* point to output exponent */
}
/* combine sign and exponent */
i = *p++;
- if (FLOAT_WORDS_BIG_ENDIAN)
+ if (REAL_WORDS_BIG_ENDIAN)
{
if (i)
*q++ = *p++ | 0x8000;
/* skip over guard word */
++p;
/* move the significand */
- if (FLOAT_WORDS_BIG_ENDIAN)
+ if (REAL_WORDS_BIG_ENDIAN)
{
for (i = 0; i < 7; i++)
*q++ = *p++;
}
}
+/* Convert e-type X to IEEE double extended format E. */
+
static void
etoe64 (x, e)
unsigned EMUSHORT *x, *e;
toe64 (xi, e);
}
-
-/* Move out internal format to ieee long double. */
+/* Convert exploded e-type X, that has already been rounded to
+ 64-bit precision, to IEEE double extended format Y. */
static void
toe64 (a, b)
q = b + 4;
#endif
#ifdef IEEE
- if (FLOAT_WORDS_BIG_ENDIAN)
+ if (REAL_WORDS_BIG_ENDIAN)
q = b;
else
{
*q-- = *p++;
#endif
#ifdef IEEE
- if (FLOAT_WORDS_BIG_ENDIAN)
+ if (REAL_WORDS_BIG_ENDIAN)
{
if (i)
*q++ = *p++ | 0x8000;
*q-- = *p++;
#endif
#ifdef IEEE
- if (FLOAT_WORDS_BIG_ENDIAN)
+ if (REAL_WORDS_BIG_ENDIAN)
{
for (i = 0; i < 4; i++)
*q++ = *p++;
#endif
}
-
-/* e type to IEEE double precision. */
+/* e type to double precision. */
#ifdef DEC
+/* Convert e-type X to DEC-format double E. */
static void
etoe53 (x, e)
etodec (x, e); /* see etodec.c */
}
+/* Convert exploded e-type X, that has already been rounded to
+ 56-bit double precision, to DEC double Y. */
+
static void
toe53 (x, y)
unsigned EMUSHORT *x, *y;
#else
#ifdef IBM
+/* Convert e-type X to IBM 370-format double E. */
static void
etoe53 (x, e)
etoibm (x, e, DFmode);
}
+/* Convert exploded e-type X, that has already been rounded to
+ 56-bit precision, to IBM 370 double Y. */
+
static void
toe53 (x, y)
unsigned EMUSHORT *x, *y;
#else /* it's neither DEC nor IBM */
+/* Convert e-type X to IEEE double E. */
+
static void
etoe53 (x, e)
unsigned EMUSHORT *x, *e;
toe53 (xi, e);
}
+/* Convert exploded e-type X, that has already been rounded to
+ 53-bit precision, to IEEE double Y. */
static void
toe53 (x, y)
#endif
p = &x[0];
#ifdef IEEE
- if (! FLOAT_WORDS_BIG_ENDIAN)
+ if (! REAL_WORDS_BIG_ENDIAN)
y += 3;
#endif
*y = 0; /* output high order */
{ /* Saturate at largest number less than infinity. */
#ifdef INFINITY
*y |= 0x7ff0;
- if (! FLOAT_WORDS_BIG_ENDIAN)
+ if (! REAL_WORDS_BIG_ENDIAN)
{
*(--y) = 0;
*(--y) = 0;
}
#else
*y |= (unsigned EMUSHORT) 0x7fef;
- if (! FLOAT_WORDS_BIG_ENDIAN)
+ if (! REAL_WORDS_BIG_ENDIAN)
{
*(--y) = 0xffff;
*(--y) = 0xffff;
}
i |= *p++ & (unsigned EMUSHORT) 0x0f; /* *p = xi[M] */
*y |= (unsigned EMUSHORT) i; /* high order output already has sign bit set */
- if (! FLOAT_WORDS_BIG_ENDIAN)
+ if (! REAL_WORDS_BIG_ENDIAN)
{
*(--y) = *p++;
*(--y) = *p++;
-/* e type to IEEE single precision. */
+/* e type to single precision. */
#ifdef IBM
+/* Convert e-type X to IBM 370 float E. */
static void
etoe24 (x, e)
etoibm (x, e, SFmode);
}
+/* Convert exploded e-type X, that has already been rounded to
+ float precision, to IBM 370 float Y. */
+
static void
toe24 (x, y)
unsigned EMUSHORT *x, *y;
}
#else
+/* Convert e-type X to IEEE float E. DEC float is the same as IEEE float. */
static void
etoe24 (x, e)
toe24 (xi, e);
}
+/* Convert exploded e-type X, that has already been rounded to
+ float precision, to IEEE float Y. */
+
static void
toe24 (x, y)
unsigned EMUSHORT *x, *y;
#endif
p = &x[0];
#ifdef IEEE
- if (! FLOAT_WORDS_BIG_ENDIAN)
+ if (! REAL_WORDS_BIG_ENDIAN)
y += 1;
#endif
#ifdef DEC
*(--y) = 0;
#endif
#ifdef IEEE
- if (! FLOAT_WORDS_BIG_ENDIAN)
+ if (! REAL_WORDS_BIG_ENDIAN)
*(--y) = 0;
else
{
*(--y) = 0xffff;
#endif
#ifdef IEEE
- if (! FLOAT_WORDS_BIG_ENDIAN)
+ if (! REAL_WORDS_BIG_ENDIAN)
*(--y) = 0xffff;
else
{
eshift (x, 8);
}
i |= *p++ & (unsigned EMUSHORT) 0x7f; /* *p = xi[M] */
- *y |= i; /* high order output already has sign bit set */
+ /* High order output already has sign bit set. */
+ *y |= i;
#ifdef DEC
*(--y) = *p;
#endif
#ifdef IEEE
- if (! FLOAT_WORDS_BIG_ENDIAN)
+ if (! REAL_WORDS_BIG_ENDIAN)
*(--y) = *p;
else
{
return (0); /* equality */
-
-
diff:
if (*(--p) > *(--q))
return (-msign); /* p is littler */
}
-
-
-
-/* Find nearest integer to x = floor (x + 0.5). */
+/* Find e-type nearest integer to X, as floor (X + 0.5). */
static void
eround (x, y)
efloor (y, y);
}
-
-
-
-/* Convert HOST_WIDE_INT to e type. */
+/* Convert HOST_WIDE_INT LP to e type Y. */
static void
ltoe (lp, y)
emovo (yi, y); /* output the answer */
}
-/* Convert unsigned HOST_WIDE_INT to e type. */
+/* Convert unsigned HOST_WIDE_INT LP to e type Y. */
static void
ultoe (lp, y)
}
-/* Find signed HOST_WIDE_INT integer and floating point fractional
- parts of e-type (packed internal format) floating point input X.
+/* Find signed HOST_WIDE_INT integer I and floating point fractional
+ part FRAC of e-type (packed internal format) floating point input X.
The integer output I has the sign of the input, except that
positive overflow is permitted if FIXUNS_TRUNC_LIKE_FIX_TRUNC.
The output e-type fraction FRAC is the positive fractional
}
-/* Find unsigned HOST_WIDE_INT integer and floating point fractional parts.
- A negative e type input yields integer output = 0
- but correct fraction. */
+/* Find unsigned HOST_WIDE_INT integer I and floating point fractional part
+ FRAC of e-type X. A negative input yields integer output = 0 but
+ correct fraction. */
static void
euifrac (x, i, frac)
emovo (xi, frac);
}
-
-
-/* Shift significand area up or down by the number of bits given by SC. */
+/* Shift the significand of exploded e-type X up or down by SC bits. */
static int
eshift (x, sc)
return ((int) lost);
}
-
-
-/* Shift normalize the significand area pointed to by argument.
- Shift count (up = positive) is returned. */
+/* Shift normalize the significand area of exploded e-type X.
+ Return the shift count (up = positive). */
static int
enormlz (x)
return (sc);
}
-
-
-
-/* Convert e type number to decimal format ASCII string.
- The constants are for 64 bit precision. */
+/* Powers of ten used in decimal <-> binary conversions. */
#define NTEN 12
#define MAXP 4096
};
#endif
+/* Convert float value X to ASCII string STRING with NDIG digits after
+ the decimal point. */
+
static void
e24toasc (x, string, ndigs)
unsigned EMUSHORT x[];
etoasc (w, string, ndigs);
}
+/* Convert double value X to ASCII string STRING with NDIG digits after
+ the decimal point. */
static void
e53toasc (x, string, ndigs)
etoasc (w, string, ndigs);
}
+/* Convert double extended value X to ASCII string STRING with NDIG digits
+ after the decimal point. */
static void
e64toasc (x, string, ndigs)
etoasc (w, string, ndigs);
}
+/* Convert 128-bit long double value X to ASCII string STRING with NDIG digits
+ after the decimal point. */
+
static void
e113toasc (x, string, ndigs)
unsigned EMUSHORT x[];
etoasc (w, string, ndigs);
}
+/* Convert e-type X to ASCII string STRING with NDIGS digits after
+ the decimal point. */
static char wstring[80]; /* working storage for ASCII output */
}
-/* Convert ASCII string to quadruple precision floating point
+/* Convert ASCII string to floating point.
- Numeric input is free field decimal number with max of 15 digits with or
- without decimal point entered as ASCII from teletype. Entering E after
- the number followed by a second number causes the second number to be
- interpreted as a power of 10 to be multiplied by the first number
- (i.e., "scientific" notation). */
+ Numeric input is a free format decimal number of any length, with
+ or without decimal point. Entering E after the number followed by an
+ integer number causes the second number to be interpreted as a power of
+ 10 to be multiplied by the first number (i.e., "scientific" notation). */
-/* ASCII to single */
+/* Convert ASCII string S to single precision float value Y. */
static void
asctoe24 (s, y)
}
-/* ASCII to double */
+/* Convert ASCII string S to double precision value Y. */
static void
asctoe53 (s, y)
}
-/* ASCII to long double */
+/* Convert ASCII string S to double extended value Y. */
static void
asctoe64 (s, y)
asctoeg (s, y, 64);
}
-/* ASCII to 128-bit long double */
+/* Convert ASCII string S to 128-bit long double Y. */
static void
asctoe113 (s, y)
asctoeg (s, y, 113);
}
-/* ASCII to super double */
+/* Convert ASCII string S to e type Y. */
static void
asctoe (s, y)
asctoeg (s, y, NBITS);
}
-
-/* ASCII to e type, with specified rounding precision = oprec. */
+/* Convert ASCII string SS to e type Y, with a specified rounding precision
+ of OPREC bits. */
static void
asctoeg (ss, y, oprec)
-/* y = largest integer not greater than x (truncated toward minus infinity) */
+/* Return Y = largest integer not greater than X (truncated toward minus
+ infinity). */
static unsigned EMUSHORT bmask[] =
{
}
-/* Returns s and exp such that s * 2**exp = x and .5 <= s < 1.
- For example, 1.1 = 0.55 * 2**1
- Handles denormalized numbers properly using long integer exp. */
+/* Return S and EXP such that S * 2^EXP = X and .5 <= S < 1.
+ For example, 1.1 = 0.55 * 2^1. */
static void
efrexp (x, exp, s)
EMULONG li;
emovi (x, xi);
+ /* Handle denormalized numbers properly using long integer exponent. */
li = (EMULONG) ((EMUSHORT) xi[1]);
if (li == 0)
*exp = (int) (li - 0x3ffe);
}
-
-
-/* Return y = x * 2**pwr2. */
+/* Return e type Y = X * 2^PWR2. */
static void
eldexp (x, pwr2, y)
}
-/* c = remainder after dividing b by a
- Least significant integer quotient bits left in equot[]. */
+/* C = remainder after dividing B by A, all e type values.
+ Least significant integer quotient bits left in EQUOT. */
static void
eremain (a, b, c)
emovo (num, c);
}
+/* Return quotient of exploded e-types NUM / DEN in EQUOT,
+ remainder in NUM. */
+
static void
eiremain (den, num)
unsigned EMUSHORT den[], num[];
j = 1;
}
else
- {
j = 0;
- }
eshup1 (equot);
equot[NI - 1] |= j;
eshup1 (num);
emdnorm (num, 0, 0, ln, 0);
}
-/* This routine may be called to report one of the following
- error conditions (in the include file mconf.h).
+/* Report an error condition CODE encountered in function NAME.
+ CODE is one of the following:
Mnemonic Value Significance
EDOM 33 Unix domain error code
ERANGE 34 Unix range error code
- The default version of the file prints the function name,
- passed to it by the pointer fctnam, followed by the
- error condition. The display is directed to the standard
- output device. The routine then returns to the calling
- program. Users may wish to modify the program to abort by
- calling exit under severe error conditions such as domain
- errors.
-
- Since all error conditions pass control to this function,
- the display may be easily changed, eliminated, or directed
- to an error logging device. */
-
-/* Note: the order of appearance of the following messages is bound to the
+ The order of appearance of the following messages is bound to the
error codes defined above. */
#define NMSGS 8
{
char errstr[80];
- /* Display string passed by calling program, which is supposed to be the
+ /* The string passed by the calling program is supposed to be the
name of the function in which the error occurred.
-
- Display error message defined by the code argument. */
+ The code argument selects which error message string will be printed. */
if ((code <= 0) || (code >= NMSGS))
code = 0;
}
#ifdef DEC
-/* Convert DEC double precision to e type. */
+/* Convert DEC double precision D to e type E. */
static void
dectoe (d, e)
emovo (y, e);
}
-
-
-/*
-; convert e type to DEC double precision
-; double d;
-; EMUSHORT e[NE];
-; etodec (e, &d);
-*/
+/* Convert e type X to DEC double precision D. */
static void
etodec (x, d)
int rndsav;
emovi (x, xi);
- exp = (EMULONG) xi[E] - (EXONE - 0201); /* adjust exponent for offsets */
-/* round off to nearest or even */
+ /* Adjust exponent for offsets. */
+ exp = (EMULONG) xi[E] - (EXONE - 0201);
+ /* Round off to nearest or even. */
rndsav = rndprc;
rndprc = 56;
emdnorm (xi, 0, 0, exp, 64);
todec (xi, d);
}
+/* Convert exploded e-type X, that has already been rounded to
+ 56-bit precision, to DEC format double Y. */
+
static void
todec (x, y)
unsigned EMUSHORT *x, *y;
#if !defined(DEC) && !defined(IBM)
case TFmode:
n = 8;
- if (FLOAT_WORDS_BIG_ENDIAN)
+ if (REAL_WORDS_BIG_ENDIAN)
p = TFbignan;
else
p = TFlittlenan;
break;
case XFmode:
n = 6;
- if (FLOAT_WORDS_BIG_ENDIAN)
+ if (REAL_WORDS_BIG_ENDIAN)
p = XFbignan;
else
p = XFlittlenan;
break;
case DFmode:
n = 4;
- if (FLOAT_WORDS_BIG_ENDIAN)
+ if (REAL_WORDS_BIG_ENDIAN)
p = DFbignan;
else
p = DFlittlenan;
case HFmode:
case SFmode:
n = 2;
- if (FLOAT_WORDS_BIG_ENDIAN)
+ if (REAL_WORDS_BIG_ENDIAN)
p = SFbignan;
else
p = SFlittlenan;
default:
abort ();
}
- if (FLOAT_WORDS_BIG_ENDIAN)
+ if (REAL_WORDS_BIG_ENDIAN)
*nan++ = (sign << 15) | *p++;
while (--n != 0)
*nan++ = *p++;
- if (! FLOAT_WORDS_BIG_ENDIAN)
+ if (! REAL_WORDS_BIG_ENDIAN)
*nan = (sign << 15) | *p;
}
/* Convert 32 bit integer to array of 16 bit pieces in target machine order.
This is the inverse operation to what the function `endian' does. */
- if (FLOAT_WORDS_BIG_ENDIAN)
+ if (REAL_WORDS_BIG_ENDIAN)
{
s[0] = (unsigned EMUSHORT) (f >> 16);
s[1] = (unsigned EMUSHORT) f;
unsigned EMUSHORT e[NE];
/* Convert array of HOST_WIDE_INT to equivalent array of 16-bit pieces. */
- if (FLOAT_WORDS_BIG_ENDIAN)
+ if (REAL_WORDS_BIG_ENDIAN)
{
s[0] = (unsigned EMUSHORT) (d[0] >> 16);
s[1] = (unsigned EMUSHORT) d[0];
/* Convert target computer unsigned 64-bit integer to e-type.
The endian-ness of DImode follows the convention for integers,
- so we use WORDS_BIG_ENDIAN here, not FLOAT_WORDS_BIG_ENDIAN. */
+ so we use WORDS_BIG_ENDIAN here, not REAL_WORDS_BIG_ENDIAN. */
static void
uditoe (di, e)
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