ieee.h File Reference

Detailed Description

IEEE floating point functions.

Functions
void	ecleaz (eNI x)
	Clear (zero-out) the given value.
idaman THREAD_SAFE void ida_export	emovo (const eNI a, eNE b)
	Move eNI => eNE.
idaman THREAD_SAFE void ida_export	emovi (const eNE a, eNI b)
	Move eNE => eNI.
idaman THREAD_SAFE int ida_export	eshift (eNI x, int sc)
	Shift NI format up (+) or down.
idaman THREAD_SAFE int ida_export	emdnorm (eNI s, int lost, int subflg, int32 exp, int rndbase)
	Normalize and round off. More...
idaman THREAD_SAFE int ida_export	ieee_realcvt (void *m, eNE e, uint16 swt)
	Standard IEEE 754 floating point conversion function. More...
idaman THREAD_SAFE int ida_export	ecmp (const eNE a, const eNE b)
	Comparison. More...
idaman THREAD_SAFE fpvalue_kind_t ida_export	get_fpvalue_kind (const eNE a, uint16 max_exp)
	See fpvalue_kind_t.
Prototypes
IDP module event prototype – should be implemented in idp
int idaapi	realcvt (void *m, eNE e, uint16 swt)
	Floating point conversion function: implemented by processor_t::realcvt. More...
int	l_realcvt (void *m, eNE e, uint16 swt)
	Little endian.
int	b_realcvt (void *m, eNE e, uint16 swt)
	Big endian.

Misc arithmetic/conversion functions
Return values 0 ok 1 overfloat / underfloat 2 illegal data (asctoreal()) 3 divide by 0 (ediv()) 4 too big for integer (eetol())
#define	eclear(a)   memset(a, 0, sizeof(eNE))
	x = 0
#define	emov(a, b)   memcpy(b, a, sizeof(eNE))
	b = a
#define	eabs(x)   (x[IEEE_NE-1] &= 0x7fff)
	x = |x|
#define	esign(x)   (x[IEEE_NE-1] & 0x8000)
	x < 0 ? More...
idaman THREAD_SAFE void ida_export	realtoasc (char *buf, size_t bufsize, const eNE x, uint mode)
	IEEE to ascii string. More...
idaman THREAD_SAFE int ida_export	asctoreal (const char **sss, eNE y)
	ascii string to IEEE
idaman THREAD_SAFE void ida_export	eltoe (sval_t l, eNE e)
	long to IEEE
idaman THREAD_SAFE void ida_export	eltoe64 (int64 l, eNE e)
	int64 to IEEE
idaman THREAD_SAFE void ida_export	eltoe64u (uint64 l, eNE e)
	uint64 to IEEE
idaman THREAD_SAFE int ida_export	eetol (sval_t *l, const eNE a, bool roundflg)
	IEEE to long (+-0.5 if flg)
idaman THREAD_SAFE int ida_export	eetol64 (int64 *l, const eNE a, bool roundflg)
	IEEE to long (+-0.5 if flg)
idaman THREAD_SAFE int ida_export	eetol64u (uint64 *l, const eNE a, bool roundflg)
	IEEE to ulong (+-0.5 if flg)
idaman THREAD_SAFE int ida_export	eldexp (const eNE a, int32 pwr2, eNE b)
	b = a*(2**pwr2)
idaman THREAD_SAFE int ida_export	eadd (const eNE a, const eNE b, eNE c, int subflg)
	if(!subflg) c = a + b, else c = a - b
idaman THREAD_SAFE int ida_export	emul (const eNE a, const eNE b, eNE c)
	c = a * b
idaman THREAD_SAFE int ida_export	ediv (const eNE a, const eNE b, eNE c)
	c = a / b
void	eneg (eNE x)
	x = -x

Macros
#define	IEEE_NE   6
	Number of 16 bit words in eNE.
#define	IEEE_NI   (IEEE_NE+3)
	Number of 16 bit words in eNI.
#define	IEEE_E   1
	Array offset to exponent.
#define	IEEE_M   2
	Array offset to high guard word.
#define	IEEE_EXONE   (0x3fff)
	The exponent of 1.0.
#define	EZERO   { 0, 0000000,0000000,0000000,0000000,0000000 }
#define	EONE   { 0, 0000000,0000000,0000000,0100000,0x3fff }
#define	REAL_ERROR_FORMAT   -1
	not supported format for current .idp
#define	REAL_ERROR_RANGE   -2
	number too big (small) for store (mem NOT modified)
#define	REAL_ERROR_BADDATA   -3
	illegal real data for load (IEEE data not filled)

Typedefs
typedef uint16	eNE[IEEE_NE]
	External x type format.
typedef uint16	eNI[IEEE_NI]
	Internal format: More...

Enumerations
enum	fpvalue_kind_t {   FPV_BADARG, FPV_NORM, FPV_NAN, FPV_PINF,   FPV_NINF }
	Check for NaN/Inf. More...

Variables
const eNE	ieee_ezero
	0.0
const eNE	ieee_eone
	1.0
const eNE	ieee_etwo
	2.0
const eNE	ieee_e32
	32.0
const eNE	ieee_elog2
	6.93147180559945309417232121458176568075500134360255E-1
const eNE	ieee_esqrt2
	1.41421356237309504880168872420969807856967187537695E0
const eNE	ieee_eoneopi
	2/sqrt(PI) = 1.12837916709551257389615890312154517168810125865800E0
const eNE	ieee_epi
	3.14159265358979323846264338327950288419716939937511E0
const eNE	ieee_eeul
	5.7721566490153286060651209008240243104215933593992E-1
max_exp values
common values for max_exp (for IEEE floating point values)
const uint32	MAXEXP_FLOAT = 0x80
const uint32	MAXEXP_DOUBLE = 0x400
const uint32	MAXEXP_LNGDBL = 0x4000

Macro Definition Documentation

#define esign

(

x

)

(x[IEEE_NE-1] & 0x8000)

x < 0 ?

Note

non standard answer is returned

Typedef Documentation

typedef uint16 eNI[IEEE_NI]

Internal format:

• 0 : sign (0/1)
• 1 : exponent (based of IEEE_EXONE). If exp = 0, value = 0.
• 2 : high word of mantissa (always zero after normalize)

Enumeration Type Documentation

enum fpvalue_kind_t

Check for NaN/Inf.

Enumerator
FPV_BADARG	wrong value of max_exp
FPV_NORM	regular value
FPV_NAN	NaN.
FPV_PINF	positive infinity
FPV_NINF	negative infinity

Function Documentation

idaman THREAD_SAFE int ida_export emdnorm	(	eNI	s,
		int	lost,
		int	subflg,
		int32	exp,
		int	rndbase
	)

Normalize and round off.

Parameters

s	the internal format number to be rounded
lost	indicates whether or not the number is exact. this is the so-called sticky bit.
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.
exp	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.
rndbase	if 0 => is the rounding control. else is processor defined base (rndprc)

Returns

success

int idaapi realcvt	(	void *	m,
		eNE	e,
		uint16	swt
	)

Floating point conversion function: implemented by processor_t::realcvt.

Parameters

m	pointer to data
e	internal IEEE format data
swt	operation: 000: load trunc. float (DEC ^F) 2 bytes (m->e) 001: load float 4 bytes (m->e) 003: load double 8 bytes (m->e) 004: load long double 10 bytes (m->e) 005: load long double 12 bytes (m->e) 010: store trunc. float (DEC ^F) 2 bytes (e->m) 011: store float 4 bytes (e->m) 013: store double 8 bytes (e->m) 014: store long double 10 bytes (e->m) 015: store long double 12 bytes (e->m)

Return values

1	ok

idaman THREAD_SAFE int ida_export ieee_realcvt	(	void *	m,
		eNE	e,
		uint16	swt
	)

Standard IEEE 754 floating point conversion function.

See comment for realcvt().

idaman THREAD_SAFE void ida_export realtoasc	(	char *	buf,
		size_t	bufsize,
		const eNE	x,
		uint	mode
	)

IEEE to ascii string.

Parameters

mode	broken down into: low byte: number of digits after '.' second byte: FPNUM_LENGTH third byte: FPNUM_DIGITS

idaman THREAD_SAFE int ida_export ecmp	(	const eNE	a,
		const eNE	b
	)

Comparison.

Return values

0	if a = b
1	if a > b
-1	if a < b