WebSVN – HelenOS-historic – Diff – //uspace/trunk/softfloat/generic/conversion.c



#include "conversion.h"
 
float64 convertFloat32ToFloat64(float32 a)
{
    float64 result;
    __u64 frac;
   
    result.parts.sign = a.parts.sign;
    result.parts.fraction = a.parts.fraction;
    result.parts.fraction <<= (FLOAT64_FRACTION_SIZE - FLOAT32_FRACTION_SIZE );
   
    if ((isFloat32Infinity(a))||(isFloat32NaN(a))) {
        result.parts.exp = 0x7FF;
        /* TODO; check if its correct for SigNaNs*/
        return result;

   
    result.parts.exp = a.parts.exp + ( (int)FLOAT64_BIAS - FLOAT32_BIAS );
    if (a.parts.exp == 0) {
        /* normalize denormalized numbers */
 
        if (result.parts.fraction == 0ll) { /* fix zero */
            result.parts.exp = 0ll;
            return result;
        }
           
        frac = result.parts.fraction;
       
        while (!(frac & (0x10000000000000ll))) {
            frac <<= 1;
            --result.parts.exp;
        };
       
        ++result.parts.exp;
        result.parts.fraction = frac;
    };
   
    return result;
   
};
 
float32 convertFloat64ToFloat32(float64 a)
{
    float32 result;
    __s32 exp;
    __u64 frac;
   
    result.parts.sign = a.parts.sign;
   
    if (isFloat64NaN(a)) {
       
        result.parts.exp = 0xFF;
       
        if (isFloat64SigNaN(a)) {
            result.parts.fraction = 0x800000; /* set first bit of fraction nonzero */
            return result;
        }
   
        result.parts.fraction = 0x1; /* fraction nonzero but its first bit is zero */
        return result;
    };
 
    if (isFloat64Infinity(a)) {
        result.parts.fraction = 0;
        result.parts.exp = 0xFF;
        return result;
    };
 
    exp = (int)a.parts.exp - FLOAT64_BIAS + FLOAT32_BIAS;
   
    if (exp >= 0xFF) {
        /*FIXME: overflow*/
        result.parts.fraction = 0;
        result.parts.exp = 0xFF;
        return result;
       
    } else if (exp <= 0 ) {
       
        /* underflow or denormalized */
       
        result.parts.exp = 0;
       
        exp *= -1; 
        if (exp > FLOAT32_FRACTION_SIZE ) {
            /* FIXME: underflow */
            result.parts.fraction = 0;
            return result;
        };
       
        /* denormalized */
       
        frac = a.parts.fraction;
        frac |= 0x10000000000000ll; /* denormalize and set hidden bit */
       
        frac >>= (FLOAT64_FRACTION_SIZE - FLOAT32_FRACTION_SIZE + 1);
       
        while (exp > 0) {
            --exp;
            frac >>= 1;
        };
        result.parts.fraction = frac;
       
        return result;
    };
 
    result.parts.exp = exp;
    result.parts.fraction = a.parts.fraction >> (FLOAT64_FRACTION_SIZE - FLOAT32_FRACTION_SIZE);
    return result;
};
 

Rev 698	Rev 804
Line 30...	Line 30...
30	#include "conversion.h"	30	#include "conversion.h"
31		31
32	float64 convertFloat32ToFloat64(float32 a)	32	float64 convertFloat32ToFloat64(float32 a)
33	{	33	{
34	float64 result;	34	float64 result;
35	__u64 mant;	35	__u64 frac;
36		36
37	result.parts.sign = a.parts.sign;	37	result.parts.sign = a.parts.sign;
38	result.parts.mantisa = a.parts.mantisa;	38	result.parts.fraction = a.parts.fraction;
39	result.parts.mantisa <<= (FLOAT64_MANTISA_SIZE - FLOAT32_MANTISA_SIZE );	39	result.parts.fraction <<= (FLOAT64_FRACTION_SIZE - FLOAT32_FRACTION_SIZE );
40		40
41	if ((isFloat32Infinity(a))\|\|(isFloat32NaN(a))) {	41	if ((isFloat32Infinity(a))\|\|(isFloat32NaN(a))) {
42	result.parts.exp = 0x7FF;	42	result.parts.exp = 0x7FF;
43	/* TODO; check if its correct for SigNaNs*/	43	/* TODO; check if its correct for SigNaNs*/
44	return result;	44	return result;
Line 46...	Line 46...
46		46
47	result.parts.exp = a.parts.exp + ( (int)FLOAT64_BIAS - FLOAT32_BIAS );	47	result.parts.exp = a.parts.exp + ( (int)FLOAT64_BIAS - FLOAT32_BIAS );
48	if (a.parts.exp == 0) {	48	if (a.parts.exp == 0) {
49	/* normalize denormalized numbers */	49	/* normalize denormalized numbers */
50		50
51	if (result.parts.mantisa == 0ll) { /* fix zero */	51	if (result.parts.fraction == 0ll) { /* fix zero */
52	result.parts.exp = 0ll;	52	result.parts.exp = 0ll;
53	return result;	53	return result;
54	}	54	}
55		55
56	mant = result.parts.mantisa;	56	frac = result.parts.fraction;
57		57
58	while (!(mant & (0x10000000000000ll))) {	58	while (!(frac & (0x10000000000000ll))) {
59	mant <<= 1;	59	frac <<= 1;
60	--result.parts.exp;	60	--result.parts.exp;
61	};	61	};
62		62
63	++result.parts.exp;	63	++result.parts.exp;
64	result.parts.mantisa = mant;	64	result.parts.fraction = frac;
65	};	65	};
66		66
67	return result;	67	return result;
68		68
69	};	69	};
70		70
71	float32 convertFloat64ToFloat32(float64 a)	71	float32 convertFloat64ToFloat32(float64 a)
72	{	72	{
73	float32 result;	73	float32 result;
74	__s32 exp;	74	__s32 exp;
75	__u64 mant;	75	__u64 frac;
76		76
77	result.parts.sign = a.parts.sign;	77	result.parts.sign = a.parts.sign;
78		78
79	if (isFloat64NaN(a)) {	79	if (isFloat64NaN(a)) {
80		80
81	result.parts.exp = 0xFF;	81	result.parts.exp = 0xFF;
82		82
83	if (isFloat64SigNaN(a)) {	83	if (isFloat64SigNaN(a)) {
84	result.parts.mantisa = 0x800000; /* set first bit of mantisa nonzero */	84	result.parts.fraction = 0x800000; /* set first bit of fraction nonzero */
85	return result;	85	return result;
86	}	86	}
87		87
88	result.parts.mantisa = 0x1; /* mantisa nonzero but its first bit is zero */	88	result.parts.fraction = 0x1; /* fraction nonzero but its first bit is zero */
89	return result;	89	return result;
90	};	90	};
91		91
92	if (isFloat64Infinity(a)) {	92	if (isFloat64Infinity(a)) {
93	result.parts.mantisa = 0;	93	result.parts.fraction = 0;
94	result.parts.exp = 0xFF;	94	result.parts.exp = 0xFF;
95	return result;	95	return result;
96	};	96	};
97		97
98	exp = (int)a.parts.exp - FLOAT64_BIAS + FLOAT32_BIAS;	98	exp = (int)a.parts.exp - FLOAT64_BIAS + FLOAT32_BIAS;
99		99
100	if (exp >= 0xFF) {	100	if (exp >= 0xFF) {
101	/FIXME: overflow/	101	/FIXME: overflow/
102	result.parts.mantisa = 0;	102	result.parts.fraction = 0;
103	result.parts.exp = 0xFF;	103	result.parts.exp = 0xFF;
104	return result;	104	return result;
105		105
106	} else if (exp <= 0 ) {	106	} else if (exp <= 0 ) {
107		107
108	/* underflow or denormalized */	108	/* underflow or denormalized */
109		109
110	result.parts.exp = 0;	110	result.parts.exp = 0;
111		111
112	exp *= -1;	112	exp *= -1;
113	if (exp > FLOAT32_MANTISA_SIZE ) {	113	if (exp > FLOAT32_FRACTION_SIZE ) {
114	/* FIXME: underflow */	114	/* FIXME: underflow */
115	result.parts.mantisa = 0;	115	result.parts.fraction = 0;
116	return result;	116	return result;
117	};	117	};
118		118
119	/* denormalized */	119	/* denormalized */
120		120
121	mant = a.parts.mantisa;	121	frac = a.parts.fraction;
122	mant \|= 0x10000000000000ll; /* denormalize and set hidden bit */	122	frac \|= 0x10000000000000ll; /* denormalize and set hidden bit */
123		123
124	mant >>= (FLOAT64_MANTISA_SIZE - FLOAT32_MANTISA_SIZE + 1);	124	frac >>= (FLOAT64_FRACTION_SIZE - FLOAT32_FRACTION_SIZE + 1);
125		125
126	while (exp > 0) {	126	while (exp > 0) {
127	--exp;	127	--exp;
128	mant >>= 1;	128	frac >>= 1;
129	};	129	};
130	result.parts.mantisa = mant;	130	result.parts.fraction = frac;
131		131
132	return result;	132	return result;
133	};	133	};
134		134
135	result.parts.exp = exp;	135	result.parts.exp = exp;
136	result.parts.mantisa = a.parts.mantisa >> (FLOAT64_MANTISA_SIZE - FLOAT32_MANTISA_SIZE);	136	result.parts.fraction = a.parts.fraction >> (FLOAT64_FRACTION_SIZE - FLOAT32_FRACTION_SIZE);
137	return result;	137	return result;
138	};	138	};
139		139

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(root)//uspace/trunk/softfloat/generic/conversion.c – Rev 698 → 804