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lvzhengyang
riscv-gcc-1
Commits
012a47cb
Commit
012a47cb
authored
Jul 11, 1994
by
Doug Evans
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gcc/config/fp-bit.c
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012a47cb
/* This is a software floating point library which can be used instead of
the floating point routines in libgcc1.c for targets without hardware
floating point.
This implements IEEE 754 format arithmetic, but does not provide a
mechanism for setting the rounding mode, or for generating or handling
exceptions.
The original code by Steve Chamberlain, hacked by Mark Eichin and Jim
Wilson, all of Cygnus Support.
This file is in the public domain. */
/* The intended way to use this file is to make two copies, add `#define FLOAT'
to one copy, then compile both copies and add them to libgcc.a. */
/* The following macros can be defined to change the behaviour of this file:
FLOAT: Implement a `float', aka SFmode, fp library. If this is not
defined, then this file implements a `double', aka DFmode, fp library.
FLOAT_ONLY: Used with FLOAT, to implement a `float' only library, i.e.
don't include float->double conversion which requires the double library.
This is useful only for machines which can't support doubles, e.g. some
8-bit processors.
CMPtype: Specify the type that floating point compares should return.
This defaults to SItype, aka int.
US_SOFTWARE_GOFAST: This makes all entry points use the same names as the
US Software goFast library. If this is not defined, the entry points use
the same names as libgcc1.c.
_DEBUG_BITFLOAT: This makes debugging the code a little easier, by adding
two integers to the FLO_union_type.
NO_NANS: Disable nan and infinity handling
SMALL_MACHINE: Useful when operations on QIs and HIs are faster
than on an SI */
typedef
SFtype
__attribute__
((
mode
(
SF
)));
typedef
DFtype
__attribute__
((
mode
(
DF
)));
typedef
int
HItype
__attribute__
((
mode
(
HI
)));
typedef
int
SItype
__attribute__
((
mode
(
SI
)));
typedef
int
DItype
__attribute__
((
mode
(
DI
)));
/* The type of the result of a fp compare */
#ifndef CMPtype
#define CMPtype SItype
#endif
typedef
unsigned
int
UHItype
__attribute__
((
mode
(
HI
)));
typedef
unsigned
int
USItype
__attribute__
((
mode
(
SI
)));
typedef
unsigned
int
UDItype
__attribute__
((
mode
(
DI
)));
#define MAX_SI_INT ((SItype) ((unsigned) (~0)>>1))
#define MAX_USI_INT ((USItype) ~0)
#ifdef FLOAT_ONLY
#define NO_DI_MODE
#endif
#ifdef FLOAT
# define NGARDS 7L
# define GARDROUND 0x3f
# define GARDMASK 0x7f
# define GARDMSB 0x40
# define EXPBITS 8
# define EXPBIAS 127
# define FRACBITS 23
# define EXPMAX (0xff)
# define QUIET_NAN 0x100000L
# define FRAC_NBITS 32
# define FRACHIGH 0x80000000L
# define FRACHIGH2 0xc0000000L
typedef
USItype
fractype
;
typedef
UHItype
halffractype
;
typedef
SFtype
FLO_type
;
typedef
SItype
intfrac
;
#else
# define PREFIXFPDP dp
# define PREFIXSFDF df
# define NGARDS 8L
# define GARDROUND 0x7f
# define GARDMASK 0xff
# define GARDMSB 0x80
# define EXPBITS 11
# define EXPBIAS 1023
# define FRACBITS 52
# define EXPMAX (0x7ff)
# define QUIET_NAN 0x8000000000000LL
# define FRAC_NBITS 64
# define FRACHIGH 0x8000000000000000LL
# define FRACHIGH2 0xc000000000000000LL
typedef
UDItype
fractype
;
typedef
USItype
halffractype
;
typedef
DFtype
FLO_type
;
typedef
DItype
intfrac
;
#endif
#ifdef US_SOFTWARE_GOFAST
# ifdef FLOAT
# define add fpadd
# define sub fpsub
# define multiply fpmul
# define divide fpdiv
# define compare fpcmp
# define si_to_float sitofp
# define float_to_si fptosi
# define float_to_usi fptoui
# define negate __negsf2
# define sf_to_df fptodp
# define dptofp dptofp
#else
# define add dpadd
# define sub dpsub
# define multiply dpmul
# define divide dpdiv
# define compare dpcmp
# define si_to_float litodp
# define float_to_si dptoli
# define float_to_usi dptoul
# define negate __negdf2
# define df_to_sf dptofp
#endif
#else
# ifdef FLOAT
# define add __addsf3
# define sub __subsf3
# define multiply __mulsf3
# define divide __divsf3
# define compare __cmpsf2
# define _eq_f2 __eqsf2
# define _ne_f2 __nesf2
# define _gt_f2 __gtsf2
# define _ge_f2 __gesf2
# define _lt_f2 __ltsf2
# define _le_f2 __lesf2
# define si_to_float __floatsisf
# define float_to_si __fixsfsi
# define float_to_usi __fixunssfsi
# define negate __negsf2
# define sf_to_df __extendsfdf2
#else
# define add __adddf3
# define sub __subdf3
# define multiply __muldf3
# define divide __divdf3
# define compare __cmpdf2
# define _eq_f2 __eqdf2
# define _ne_f2 __nedf2
# define _gt_f2 __gtdf2
# define _ge_f2 __gedf2
# define _lt_f2 __ltdf2
# define _le_f2 __ledf2
# define si_to_float __floatsidf
# define float_to_si __fixdfsi
# define float_to_usi __fixunsdfsi
# define negate __negdf2
# define df_to_sf __truncdfsf2
# endif
#endif
#define INLINE __inline__
/* Preserve the sticky-bit when shifting fractions to the right. */
#define LSHIFT(a) { a = (a & 1) | (a >> 1); }
/* numeric parameters */
/* F_D_BITOFF is the number of bits offset between the MSB of the mantissa
of a float and of a double. Assumes there are only two float types.
(double::FRAC_BITS+double::NGARGS-(float::FRAC_BITS-float::NGARDS))
*/
#define F_D_BITOFF (52+8-(23+7))
#define NORMAL_EXPMIN (-(EXPBIAS)+1)
#define IMPLICIT_1 (1LL<<(FRACBITS+NGARDS))
#define IMPLICIT_2 (1LL<<(FRACBITS+1+NGARDS))
/* common types */
typedef
enum
{
CLASS_SNAN
,
CLASS_QNAN
,
CLASS_ZERO
,
CLASS_NUMBER
,
CLASS_INFINITY
}
fp_class_type
;
typedef
struct
{
#ifdef SMALL_MACHINE
char
class
;
unsigned
char
sign
;
short
normal_exp
;
#else
fp_class_type
class
;
unsigned
int
sign
;
int
normal_exp
;
#endif
union
{
fractype
ll
;
halffractype
l
[
2
];
}
fraction
;
}
fp_number_type
;
typedef
union
{
FLO_type
value
;
#ifdef _DEBUG_BITFLOAT
int
l
[
2
];
#endif
struct
{
#ifndef FLOAT_BIT_ORDER_MISMATCH
unsigned
int
sign
:
1
;
unsigned
int
exp
:
EXPBITS
;
fractype
fraction
:
FRACBITS
;
#else
fractype
fraction
:
FRACBITS
;
unsigned
int
exp
:
EXPBITS
;
unsigned
int
sign
:
1
;
#endif
}
bits
;
}
FLO_union_type
;
/* end of header */
/* IEEE "special" number predicates */
#ifdef NO_NANS
#define nan() 0
#define isnan(x) 0
#define isinf(x) 0
#else
INLINE
static
fp_number_type
*
nan
()
{
static
fp_number_type
thenan
;
return
&
thenan
;
}
INLINE
static
int
isnan
(
fp_number_type
*
x
)
{
return
x
->
class
==
CLASS_SNAN
||
x
->
class
==
CLASS_QNAN
;
}
INLINE
static
int
isinf
(
fp_number_type
*
x
)
{
return
x
->
class
==
CLASS_INFINITY
;
}
#endif
INLINE
static
int
iszero
(
fp_number_type
*
x
)
{
return
x
->
class
==
CLASS_ZERO
;
}
INLINE
static
void
flip_sign
(
fp_number_type
*
x
)
{
x
->
sign
=
!
x
->
sign
;
}
static
FLO_type
pack_d
(
fp_number_type
*
src
)
{
FLO_union_type
dst
;
fractype
fraction
=
src
->
fraction
.
ll
;
/* wasn't unsigned before? */
dst
.
bits
.
sign
=
src
->
sign
;
if
(
isnan
(
src
))
{
dst
.
bits
.
exp
=
EXPMAX
;
dst
.
bits
.
fraction
=
src
->
fraction
.
ll
;
if
(
src
->
class
==
CLASS_QNAN
||
1
)
{
dst
.
bits
.
fraction
|=
QUIET_NAN
;
}
}
else
if
(
isinf
(
src
))
{
dst
.
bits
.
exp
=
EXPMAX
;
dst
.
bits
.
fraction
=
0
;
}
else
if
(
iszero
(
src
))
{
dst
.
bits
.
exp
=
0
;
dst
.
bits
.
fraction
=
0
;
}
else
if
(
fraction
==
0
)
{
dst
.
value
=
0
;
}
else
{
if
(
src
->
normal_exp
<
NORMAL_EXPMIN
)
{
/* This number's exponent is too low to fit into the bits
available in the number, so we'll store 0 in the exponent and
shift the fraction to the right to make up for it. */
int
shift
=
NORMAL_EXPMIN
-
src
->
normal_exp
;
dst
.
bits
.
exp
=
0
;
if
(
shift
>
FRAC_NBITS
-
NGARDS
)
{
/* No point shifting, since it's more that 64 out. */
fraction
=
0
;
}
else
{
/* Shift by the value */
fraction
>>=
shift
;
}
fraction
>>=
NGARDS
;
dst
.
bits
.
fraction
=
fraction
;
}
else
if
(
src
->
normal_exp
>
EXPBIAS
)
{
dst
.
bits
.
exp
=
EXPMAX
;
dst
.
bits
.
fraction
=
0
;
}
else
{
dst
.
bits
.
exp
=
src
->
normal_exp
+
EXPBIAS
;
/* IF the gard bits are the all zero, but the first, then we're
half way between two numbers, choose the one which makes the
lsb of the answer 0. */
if
((
fraction
&
GARDMASK
)
==
GARDMSB
)
{
if
(
fraction
&
(
1
<<
NGARDS
))
fraction
+=
GARDROUND
+
1
;
}
else
{
/* Add a one to the guards to round up */
fraction
+=
GARDROUND
;
}
if
(
fraction
>=
IMPLICIT_2
)
{
fraction
>>=
1
;
dst
.
bits
.
exp
+=
1
;
}
fraction
>>=
NGARDS
;
dst
.
bits
.
fraction
=
fraction
;
}
}
return
dst
.
value
;
}
static
void
unpack_d
(
FLO_union_type
*
src
,
fp_number_type
*
dst
)
{
fractype
fraction
=
src
->
bits
.
fraction
;
dst
->
sign
=
src
->
bits
.
sign
;
if
(
src
->
bits
.
exp
==
0
)
{
/* Hmm. Looks like 0 */
if
(
fraction
==
0
)
{
/* tastes like zero */
dst
->
class
=
CLASS_ZERO
;
}
else
{
/* Zero exponent with non zero fraction - it's denormalized,
so there isn't a leading implicit one - we'll shift it so
it gets one. */
dst
->
normal_exp
=
src
->
bits
.
exp
-
EXPBIAS
+
1
;
fraction
<<=
NGARDS
;
dst
->
class
=
CLASS_NUMBER
;
#if 1
while
(
fraction
<
IMPLICIT_1
)
{
fraction
<<=
1
;
dst
->
normal_exp
--
;
}
#endif
dst
->
fraction
.
ll
=
fraction
;
}
}
else
if
(
src
->
bits
.
exp
==
EXPMAX
)
{
/* Huge exponent*/
if
(
fraction
==
0
)
{
/* Attatched to a zero fraction - means infinity */
dst
->
class
=
CLASS_INFINITY
;
}
else
{
/* Non zero fraction, means nan */
if
(
dst
->
sign
)
{
dst
->
class
=
CLASS_SNAN
;
}
else
{
dst
->
class
=
CLASS_QNAN
;
}
/* Keep the fraction part as the nan number */
dst
->
fraction
.
ll
=
fraction
;
}
}
else
{
/* Nothing strange about this number */
dst
->
normal_exp
=
src
->
bits
.
exp
-
EXPBIAS
;
dst
->
class
=
CLASS_NUMBER
;
dst
->
fraction
.
ll
=
(
fraction
<<
NGARDS
)
|
IMPLICIT_1
;
}
}
static
fp_number_type
*
_fpadd_parts
(
fp_number_type
*
a
,
fp_number_type
*
b
,
fp_number_type
*
tmp
)
{
intfrac
tfraction
;
/* Put commonly used fields in local variables. */
int
a_normal_exp
;
int
b_normal_exp
;
fractype
a_fraction
;
fractype
b_fraction
;
if
(
isnan
(
a
))
{
return
a
;
}
if
(
isnan
(
b
))
{
return
b
;
}
if
(
isinf
(
a
))
{
return
a
;
}
if
(
isinf
(
b
))
{
return
b
;
}
if
(
iszero
(
b
))
{
return
a
;
}
if
(
iszero
(
a
))
{
return
b
;
}
/* Got two numbers. shift the smaller and increment the exponent till
they're the same */
{
int
diff
;
a_normal_exp
=
a
->
normal_exp
;
b_normal_exp
=
b
->
normal_exp
;
a_fraction
=
a
->
fraction
.
ll
;
b_fraction
=
b
->
fraction
.
ll
;
diff
=
a_normal_exp
-
b_normal_exp
;
if
(
diff
<
0
)
diff
=
-
diff
;
if
(
diff
<
FRAC_NBITS
)
{
/* ??? This does shifts one bit at a time. Optimize. */
while
(
a_normal_exp
>
b_normal_exp
)
{
b_normal_exp
++
;
LSHIFT
(
b_fraction
);
}
while
(
b_normal_exp
>
a_normal_exp
)
{
a_normal_exp
++
;
LSHIFT
(
a_fraction
);
}
}
else
{
/* Somethings's up.. choose the biggest */
if
(
a_normal_exp
>
b_normal_exp
)
{
b_normal_exp
=
a_normal_exp
;
b_fraction
=
0
;
}
else
{
a_normal_exp
=
b_normal_exp
;
a_fraction
=
0
;
}
}
}
if
(
a
->
sign
!=
b
->
sign
)
{
if
(
a
->
sign
)
{
tfraction
=
-
a_fraction
+
b_fraction
;
}
else
{
tfraction
=
a_fraction
-
b_fraction
;
}
if
(
tfraction
>
0
)
{
tmp
->
sign
=
0
;
tmp
->
normal_exp
=
a_normal_exp
;
tmp
->
fraction
.
ll
=
tfraction
;
}
else
{
tmp
->
sign
=
1
;
tmp
->
normal_exp
=
a_normal_exp
;
tmp
->
fraction
.
ll
=
-
tfraction
;
}
/* and renomalize it */
while
(
tmp
->
fraction
.
ll
<
IMPLICIT_1
&&
tmp
->
fraction
.
ll
)
{
tmp
->
fraction
.
ll
<<=
1
;
tmp
->
normal_exp
--
;
}
}
else
{
tmp
->
sign
=
a
->
sign
;
tmp
->
normal_exp
=
a_normal_exp
;
tmp
->
fraction
.
ll
=
a_fraction
+
b_fraction
;
}
tmp
->
class
=
CLASS_NUMBER
;
/* Now the fraction is added, we have to shift down to renormalize the
number */
if
(
tmp
->
fraction
.
ll
>=
IMPLICIT_2
)
{
LSHIFT
(
tmp
->
fraction
.
ll
);
tmp
->
normal_exp
++
;
}
return
tmp
;
}
FLO_type
add
(
FLO_type
arg_a
,
FLO_type
arg_b
)
{
fp_number_type
a
;
fp_number_type
b
;
fp_number_type
tmp
;
fp_number_type
*
res
;
unpack_d
((
FLO_union_type
*
)
&
arg_a
,
&
a
);
unpack_d
((
FLO_union_type
*
)
&
arg_b
,
&
b
);
res
=
_fpadd_parts
(
&
a
,
&
b
,
&
tmp
);
return
pack_d
(
res
);
}
FLO_type
sub
(
FLO_type
arg_a
,
FLO_type
arg_b
)
{
fp_number_type
a
;
fp_number_type
b
;
fp_number_type
tmp
;
fp_number_type
*
res
;
unpack_d
((
FLO_union_type
*
)
&
arg_a
,
&
a
);
unpack_d
((
FLO_union_type
*
)
&
arg_b
,
&
b
);
b
.
sign
^=
1
;
res
=
_fpadd_parts
(
&
a
,
&
b
,
&
tmp
);
return
pack_d
(
res
);
}
static
fp_number_type
*
_fpmul_parts
(
fp_number_type
*
a
,
fp_number_type
*
b
,
fp_number_type
*
tmp
)
{
fractype
low
=
0
;
fractype
high
=
0
;
if
(
isnan
(
a
))
{
a
->
sign
=
a
->
sign
!=
b
->
sign
;
return
a
;
}
if
(
isnan
(
b
))
{
b
->
sign
=
a
->
sign
!=
b
->
sign
;
return
b
;
}
if
(
isinf
(
a
))
{
if
(
iszero
(
b
))
return
nan
();
a
->
sign
=
a
->
sign
!=
b
->
sign
;
return
a
;
}
if
(
isinf
(
b
))
{
if
(
iszero
(
a
))
{
return
nan
();
}
b
->
sign
=
a
->
sign
!=
b
->
sign
;
return
b
;
}
if
(
iszero
(
a
))
{
a
->
sign
=
a
->
sign
!=
b
->
sign
;
return
a
;
}
if
(
iszero
(
b
))
{
b
->
sign
=
a
->
sign
!=
b
->
sign
;
return
b
;
}
/* Calculate the mantissa by multiplying both 64bit numbers to get a
128 bit number */
{
fractype
x
=
a
->
fraction
.
ll
;
fractype
ylow
=
b
->
fraction
.
ll
;
fractype
yhigh
=
0
;
int
bit
;
#if defined(NO_DI_MODE)
{
/* ??? This does multiplies one bit at a time. Optimize. */
for
(
bit
=
0
;
bit
<
FRAC_NBITS
;
bit
++
)
{
int
carry
;
if
(
x
&
1
)
{
carry
=
(
low
+=
ylow
)
<
ylow
;
high
+=
yhigh
+
carry
;
}
yhigh
<<=
1
;
if
(
ylow
&
FRACHIGH
)
{
yhigh
|=
1
;
}
ylow
<<=
1
;
x
>>=
1
;
}
}
#elif defined(FLOAT)
{
/* Multiplying two 32 bit numbers to get a 64 bit number on
a machine with DI, so we're safe */
DItype
answer
=
(
DItype
)(
a
->
fraction
.
ll
)
*
(
DItype
)(
b
->
fraction
.
ll
);
high
=
answer
>>
32
;
low
=
answer
;
}
#else
/* Doing a 64*64 to 128 */
{
UDItype
nl
=
a
->
fraction
.
ll
;
UDItype
nh
=
a
->
fraction
.
ll
>>
32
;
UDItype
ml
=
b
->
fraction
.
ll
;
UDItype
mh
=
b
->
fraction
.
ll
>>
32
;
UDItype
pp_ll
=
ml
*
nl
;
UDItype
pp_hl
=
mh
*
nl
;
UDItype
pp_lh
=
ml
*
nh
;
UDItype
pp_hh
=
mh
*
nh
;
UDItype
res2
=
0
;
UDItype
res0
=
0
;
UDItype
ps_hh__
=
pp_hl
+
pp_lh
;
if
(
ps_hh__
<
pp_hl
)
res2
+=
0x100000000LL
;
pp_hl
=
(
ps_hh__
<<
32
)
&
0xffffffff00000000LL
;
res0
=
pp_ll
+
pp_hl
;
if
(
res0
<
pp_ll
)
res2
++
;
res2
+=
((
ps_hh__
>>
32
)
&
0xffffffffL
)
+
pp_hh
;
high
=
res2
;
low
=
res0
;
}
#endif
}
tmp
->
normal_exp
=
a
->
normal_exp
+
b
->
normal_exp
;
tmp
->
sign
=
a
->
sign
!=
b
->
sign
;
#ifdef FLOAT
tmp
->
normal_exp
+=
2
;
/* ??????????????? */
#else
tmp
->
normal_exp
+=
4
;
/* ??????????????? */
#endif
while
(
high
>=
IMPLICIT_2
)
{
tmp
->
normal_exp
++
;
if
(
high
&
1
)
{
low
>>=
1
;
low
|=
FRACHIGH
;
}
high
>>=
1
;
}
while
(
high
<
IMPLICIT_1
)
{
tmp
->
normal_exp
--
;
high
<<=
1
;
if
(
low
&
FRACHIGH
)
high
|=
1
;
low
<<=
1
;
}
/* rounding is tricky. if we only round if it won't make us round later. */
#if 0
if (low & FRACHIGH2)
{
if (((high & GARDMASK) != GARDMSB)
&& (((high + 1) & GARDMASK) == GARDMSB))
{
/* don't round, it gets done again later. */
}
else
{
high++;
}
}
#endif
if
((
high
&
GARDMASK
)
==
GARDMSB
)
{
if
(
high
&
(
1
<<
NGARDS
))
{
/* half way, so round to even */
high
+=
GARDROUND
+
1
;
}
else
if
(
low
)
{
/* but we really weren't half way */
high
+=
GARDROUND
+
1
;
}
}
tmp
->
fraction
.
ll
=
high
;
tmp
->
class
=
CLASS_NUMBER
;
return
tmp
;
}
FLO_type
multiply
(
FLO_type
arg_a
,
FLO_type
arg_b
)
{
fp_number_type
a
;
fp_number_type
b
;
fp_number_type
tmp
;
fp_number_type
*
res
;
unpack_d
((
FLO_union_type
*
)
&
arg_a
,
&
a
);
unpack_d
((
FLO_union_type
*
)
&
arg_b
,
&
b
);
res
=
_fpmul_parts
(
&
a
,
&
b
,
&
tmp
);
return
pack_d
(
res
);
}
static
fp_number_type
*
_fpdiv_parts
(
fp_number_type
*
a
,
fp_number_type
*
b
,
fp_number_type
*
tmp
)
{
fractype
low
=
0
;
fractype
high
=
0
;
fractype
r0
,
r1
,
y0
,
y1
,
bit
;
fractype
q
;
fractype
numerator
;
fractype
denominator
;
fractype
quotient
;
fractype
remainder
;
if
(
isnan
(
a
))
{
return
a
;
}
if
(
isnan
(
b
))
{
return
b
;
}
if
(
isinf
(
a
)
||
iszero
(
a
))
{
if
(
a
->
class
==
b
->
class
)
return
nan
();
return
a
;
}
a
->
sign
=
a
->
sign
^
b
->
sign
;
if
(
isinf
(
b
))
{
a
->
fraction
.
ll
=
0
;
a
->
normal_exp
=
0
;
return
a
;
}
if
(
iszero
(
b
))
{
a
->
class
=
CLASS_INFINITY
;
return
b
;
}
/* Calculate the mantissa by multiplying both 64bit numbers to get a
128 bit number */
{
int
carry
;
intfrac
d0
,
d1
;
/* weren't unsigned before ??? */
/* quotient =
( numerator / denominator) * 2^(numerator exponent - denominator exponent)
*/
a
->
normal_exp
=
a
->
normal_exp
-
b
->
normal_exp
;
numerator
=
a
->
fraction
.
ll
;
denominator
=
b
->
fraction
.
ll
;
if
(
numerator
<
denominator
)
{
/* Fraction will be less than 1.0 */
numerator
*=
2
;
a
->
normal_exp
--
;
}
bit
=
IMPLICIT_1
;
quotient
=
0
;
/* ??? Does divide one bit at a time. Optimize. */
while
(
bit
)
{
if
(
numerator
>=
denominator
)
{
quotient
|=
bit
;
numerator
-=
denominator
;
}
bit
>>=
1
;
numerator
*=
2
;
}
if
((
quotient
&
GARDMASK
)
==
GARDMSB
)
{
if
(
quotient
&
(
1
<<
NGARDS
))
{
/* half way, so round to even */
quotient
+=
GARDROUND
+
1
;
}
else
if
(
numerator
)
{
/* but we really weren't half way, more bits exist */
quotient
+=
GARDROUND
+
1
;
}
}
a
->
fraction
.
ll
=
quotient
;
return
(
a
);
}
}
FLO_type
divide
(
FLO_type
arg_a
,
FLO_type
arg_b
)
{
fp_number_type
a
;
fp_number_type
b
;
fp_number_type
tmp
;
fp_number_type
*
res
;
unpack_d
((
FLO_union_type
*
)
&
arg_a
,
&
a
);
unpack_d
((
FLO_union_type
*
)
&
arg_b
,
&
b
);
res
=
_fpdiv_parts
(
&
a
,
&
b
,
&
tmp
);
return
pack_d
(
res
);
}
/* according to the demo, fpcmp returns a comparison with 0... thus
a<b -> -1
a==b -> 0
a>b -> +1
*/
static
int
_fpcmp_parts
(
fp_number_type
*
a
,
fp_number_type
*
b
)
{
#if 0
/* either nan -> unordered. Must be checked outside of this routine. */
if (isnan (a) && isnan (b))
{
return 1; /* still unordered! */
}
#endif
if
(
isnan
(
a
)
||
isnan
(
b
))
{
return
1
;
/* how to indicate unordered compare? */
}
if
(
isinf
(
a
)
&&
isinf
(
b
))
{
/* +inf > -inf, but +inf != +inf */
/* b \a| +inf(0)| -inf(1)
______\+--------+--------
+inf(0)| a==b(0)| a<b(-1)
-------+--------+--------
-inf(1)| a>b(1) | a==b(0)
-------+--------+--------
So since unordered must be non zero, just line up the columns...
*/
return
b
->
sign
-
a
->
sign
;
}
/* but not both... */
if
(
isinf
(
a
))
{
return
a
->
sign
?
-
1
:
1
;
}
if
(
isinf
(
b
))
{
return
b
->
sign
?
1
:
-
1
;
}
if
(
iszero
(
a
)
&&
iszero
(
b
))
{
return
0
;
}
if
(
iszero
(
a
))
{
return
b
->
sign
?
1
:
-
1
;
}
if
(
iszero
(
b
))
{
return
a
->
sign
?
-
1
:
1
;
}
/* now both are "normal". */
if
(
a
->
sign
!=
b
->
sign
)
{
/* opposite signs */
return
a
->
sign
?
-
1
:
1
;
}
/* same sign; exponents? */
if
(
a
->
normal_exp
>
b
->
normal_exp
)
{
return
a
->
sign
?
-
1
:
1
;
}
if
(
a
->
normal_exp
<
b
->
normal_exp
)
{
return
a
->
sign
?
1
:
-
1
;
}
/* same exponents; check size. */
if
(
a
->
fraction
.
ll
>
b
->
fraction
.
ll
)
{
return
a
->
sign
?
-
1
:
1
;
}
if
(
a
->
fraction
.
ll
<
b
->
fraction
.
ll
)
{
return
a
->
sign
?
1
:
-
1
;
}
/* after all that, they're equal. */
return
0
;
}
CMPtype
compare
(
FLO_type
arg_a
,
FLO_type
arg_b
)
{
fp_number_type
a
;
fp_number_type
b
;
unpack_d
((
FLO_union_type
*
)
&
arg_a
,
&
a
);
unpack_d
((
FLO_union_type
*
)
&
arg_b
,
&
b
);
return
_fpcmp_parts
(
&
a
,
&
b
);
}
#ifndef US_SOFTWARE_GOFAST
/* These should be optimized for their specific tasks someday. */
CMPtype
_eq_f2
(
FLO_type
arg_a
,
FLO_type
arg_b
)
{
fp_number_type
a
;
fp_number_type
b
;
unpack_d
((
FLO_union_type
*
)
&
arg_a
,
&
a
);
unpack_d
((
FLO_union_type
*
)
&
arg_b
,
&
b
);
if
(
isnan
(
&
a
)
||
isnan
(
&
b
))
return
1
;
/* false, truth == 0 */
return
_fpcmp_parts
(
&
a
,
&
b
)
;
}
CMPtype
_ne_f2
(
FLO_type
arg_a
,
FLO_type
arg_b
)
{
fp_number_type
a
;
fp_number_type
b
;
unpack_d
((
FLO_union_type
*
)
&
arg_a
,
&
a
);
unpack_d
((
FLO_union_type
*
)
&
arg_b
,
&
b
);
if
(
isnan
(
&
a
)
||
isnan
(
&
b
))
return
1
;
/* true, truth != 0 */
return
_fpcmp_parts
(
&
a
,
&
b
)
;
}
CMPtype
_gt_f2
(
FLO_type
arg_a
,
FLO_type
arg_b
)
{
fp_number_type
a
;
fp_number_type
b
;
unpack_d
((
FLO_union_type
*
)
&
arg_a
,
&
a
);
unpack_d
((
FLO_union_type
*
)
&
arg_b
,
&
b
);
if
(
isnan
(
&
a
)
||
isnan
(
&
b
))
return
-
1
;
/* false, truth > 0 */
return
_fpcmp_parts
(
&
a
,
&
b
);
}
CMPtype
_ge_f2
(
FLO_type
arg_a
,
FLO_type
arg_b
)
{
fp_number_type
a
;
fp_number_type
b
;
unpack_d
((
FLO_union_type
*
)
&
arg_a
,
&
a
);
unpack_d
((
FLO_union_type
*
)
&
arg_b
,
&
b
);
if
(
isnan
(
&
a
)
||
isnan
(
&
b
))
return
-
1
;
/* false, truth >= 0 */
return
_fpcmp_parts
(
&
a
,
&
b
)
;
}
CMPtype
_lt_f2
(
FLO_type
arg_a
,
FLO_type
arg_b
)
{
fp_number_type
a
;
fp_number_type
b
;
unpack_d
((
FLO_union_type
*
)
&
arg_a
,
&
a
);
unpack_d
((
FLO_union_type
*
)
&
arg_b
,
&
b
);
if
(
isnan
(
&
a
)
||
isnan
(
&
b
))
return
1
;
/* false, truth < 0 */
return
_fpcmp_parts
(
&
a
,
&
b
);
}
CMPtype
_le_f2
(
FLO_type
arg_a
,
FLO_type
arg_b
)
{
fp_number_type
a
;
fp_number_type
b
;
unpack_d
((
FLO_union_type
*
)
&
arg_a
,
&
a
);
unpack_d
((
FLO_union_type
*
)
&
arg_b
,
&
b
);
if
(
isnan
(
&
a
)
||
isnan
(
&
b
))
return
1
;
/* false, truth <= 0 */
return
_fpcmp_parts
(
&
a
,
&
b
)
;
}
#endif
/* ! US_SOFTWARE_GOFAST */
FLO_type
si_to_float
(
SItype
arg_a
)
{
fp_number_type
in
;
in
.
class
=
CLASS_NUMBER
;
in
.
sign
=
arg_a
<
0
;
if
(
!
arg_a
)
{
in
.
class
=
CLASS_ZERO
;
}
else
{
in
.
normal_exp
=
FRACBITS
+
NGARDS
;
if
(
in
.
sign
)
{
/* Special case for minint, since there is no +ve integer
representation for it */
if
(
arg_a
==
0x80000000
)
{
return
-
2147483648
.
0
;
}
in
.
fraction
.
ll
=
(
-
arg_a
);
}
else
in
.
fraction
.
ll
=
arg_a
;
while
(
in
.
fraction
.
ll
<
(
1LL
<<
(
FRACBITS
+
NGARDS
)))
{
in
.
fraction
.
ll
<<=
1
;
in
.
normal_exp
-=
1
;
}
}
return
pack_d
(
&
in
);
}
SItype
float_to_si
(
FLO_type
arg_a
)
{
fp_number_type
a
;
SItype
tmp
;
unpack_d
((
FLO_union_type
*
)
&
arg_a
,
&
a
);
if
(
iszero
(
&
a
))
return
0
;
if
(
isnan
(
&
a
))
return
0
;
/* get reasonable MAX_SI_INT... */
if
(
isinf
(
&
a
))
return
a
.
sign
?
MAX_SI_INT
:
(
-
MAX_SI_INT
)
-
1
;
/* it is a number, but a small one */
if
(
a
.
normal_exp
<
0
)
return
0
;
if
(
a
.
normal_exp
>
30
)
return
a
.
sign
?
(
-
MAX_SI_INT
)
-
1
:
MAX_SI_INT
;
tmp
=
a
.
fraction
.
ll
>>
((
FRACBITS
+
NGARDS
)
-
a
.
normal_exp
);
return
a
.
sign
?
(
-
tmp
)
:
(
tmp
);
}
#ifdef US_SOFTWARE_GOFAST
/* While libgcc2.c defines its own __fixunssfsi and __fixunsdfsi routines,
we also define them for GOFAST because the ones in libgcc2.c have the
wrong names and I'd rather define these here and keep GOFAST CYG-LOC's
out of libgcc2.c. We can't define these here if not GOFAST because then
there'd be duplicate copies. */
USItype
float_to_usi
(
FLO_type
arg_a
)
{
fp_number_type
a
;
unpack_d
((
FLO_union_type
*
)
&
arg_a
,
&
a
);
if
(
iszero
(
&
a
))
return
0
;
if
(
isnan
(
&
a
))
return
0
;
/* get reasonable MAX_USI_INT... */
if
(
isinf
(
&
a
))
return
a
.
sign
?
MAX_USI_INT
:
0
;
/* it is a negative number */
if
(
a
.
sign
)
return
0
;
/* it is a number, but a small one */
if
(
a
.
normal_exp
<
0
)
return
0
;
if
(
a
.
normal_exp
>
31
)
return
MAX_USI_INT
;
else
if
(
a
.
normal_exp
>
(
FRACBITS
+
NGARDS
))
return
a
.
fraction
.
ll
<<
((
FRACBITS
+
NGARDS
)
-
a
.
normal_exp
);
else
return
a
.
fraction
.
ll
>>
((
FRACBITS
+
NGARDS
)
-
a
.
normal_exp
);
}
#endif
FLO_type
negate
(
FLO_type
arg_a
)
{
fp_number_type
a
;
unpack_d
((
FLO_union_type
*
)
&
arg_a
,
&
a
);
flip_sign
(
&
a
);
return
pack_d
(
&
a
);
}
#ifdef FLOAT
SFtype
__make_fp
(
fp_class_type
class
,
unsigned
int
sign
,
int
exp
,
USItype
frac
)
{
fp_number_type
in
;
in
.
class
=
class
;
in
.
sign
=
sign
;
in
.
normal_exp
=
exp
;
in
.
fraction
.
ll
=
frac
;
return
pack_d
(
&
in
);
}
#ifndef FLOAT_ONLY
/* This enables one to build an fp library that supports float but not double.
Otherwise, we would get an undefined reference to __make_dp.
This is needed for some 8-bit ports that can't handle well values that
are 8-bytes in size, so we just don't support double for them at all. */
extern
DFtype
__make_dp
(
fp_class_type
,
unsigned
int
,
int
,
UDItype
frac
);
DFtype
sf_to_df
(
SFtype
arg_a
)
{
fp_number_type
in
;
unpack_d
((
FLO_union_type
*
)
&
arg_a
,
&
in
);
return
__make_dp
(
in
.
class
,
in
.
sign
,
in
.
normal_exp
,
((
UDItype
)
in
.
fraction
.
ll
)
<<
F_D_BITOFF
);
}
#endif
#endif
#ifndef FLOAT
extern
SFtype
__make_fp
(
fp_class_type
,
unsigned
int
,
int
,
USItype
);
DFtype
__make_dp
(
fp_class_type
class
,
unsigned
int
sign
,
int
exp
,
UDItype
frac
)
{
fp_number_type
in
;
in
.
class
=
class
;
in
.
sign
=
sign
;
in
.
normal_exp
=
exp
;
in
.
fraction
.
ll
=
frac
;
return
pack_d
(
&
in
);
}
SFtype
df_to_sf
(
DFtype
arg_a
)
{
fp_number_type
in
;
unpack_d
((
FLO_union_type
*
)
&
arg_a
,
&
in
);
return
__make_fp
(
in
.
class
,
in
.
sign
,
in
.
normal_exp
,
in
.
fraction
.
ll
>>
F_D_BITOFF
);
}
#endif
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