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dndungudndungu
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chore: upgrade to go 1.25
1 parent 530f858 commit 836f115

6 files changed

Lines changed: 345 additions & 482 deletions

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‎convert.go‎

Lines changed: 143 additions & 214 deletions
Original file line numberDiff line numberDiff line change
@@ -1,240 +1,169 @@
11
package float16
22

33
import (
4+
"fmt"
45
"math"
5-
6-
"github.com/x448/float16"
6+
"strconv"
77
)
88

9-
// Converter holds the conversion and rounding modes for float16 operations.
10-
type Converter struct {
11-
ConversionMode ConversionMode
12-
RoundingMode RoundingMode
13-
}
14-
15-
// NewConverter creates a new Converter with the specified modes.
16-
func NewConverter(convMode ConversionMode, roundMode RoundingMode) *Converter {
17-
return &Converter{
18-
ConversionMode: convMode,
19-
RoundingMode: roundMode,
20-
}
21-
}
22-
23-
// ToFloat16 converts a float32 value to Float16 format using the Converter's settings.
24-
func (c *Converter) ToFloat16(f32 float32) Float16 {
25-
return Float16(float16.Fromfloat32(f32).Bits())
26-
}
27-
28-
// ToFloat16 converts a float32 to Float16 with default conversion and rounding modes
29-
func ToFloat16(f32 float32) Float16 {
30-
return NewConverter(DefaultConversionMode, DefaultRoundingMode).ToFloat16(f32)
31-
}
32-
33-
// ToFloat16WithMode converts a float32 to Float16 with specified conversion and rounding modes
34-
func (c *Converter) ToFloat16WithMode(f32 float32) (Float16, error) {
35-
convMode := c.ConversionMode
36-
if convMode == ModeStrict {
37-
if math.IsInf(float64(f32), 0) {
38-
return 0, &Float16Error{Code: ErrInfinity}
9+
// FromFloat32 converts a float32 value to a Float16 value.
10+
// It handles special cases like NaN, infinities, and zeros.
11+
// The conversion follows IEEE 754-2008 rules for half-precision.
12+
func FromFloat32(f32 float32) Float16 {
13+
f32Bits := math.Float32bits(f32)
14+
sign := f32Bits & 0x80000000
15+
exp := (f32Bits >> 23) & 0xFF
16+
mant := f32Bits & 0x7FFFFF
17+
18+
var f16Bits uint16
19+
20+
if exp == 0xFF { // NaN or Infinity
21+
if mant != 0 { // NaN
22+
f16Bits = 0x7E00 // Quiet NaN
23+
} else { // Infinity
24+
if sign != 0 {
25+
f16Bits = 0xFC00 // Negative Infinity
26+
} else {
27+
f16Bits = 0x7C00 // Positive Infinity
28+
}
3929
}
40-
if math.IsNaN(float64(f32)) {
41-
return 0, &Float16Error{Code: ErrNaN}
30+
} else if exp == 0 { // Zero or Denormalized
31+
if mant == 0 { // Zero
32+
if sign != 0 {
33+
f16Bits = 0x8000 // Negative Zero
34+
} else {
35+
f16Bits = 0x0000 // Positive Zero
36+
}
37+
} else { // Denormalized float32, convert to float16 denormalized or zero
38+
// Shift mantissa right to align with float16 denormalized range
39+
// This is a simplified approach and might not be perfectly accurate for all denormals
40+
// A more robust implementation would involve proper rounding and handling of underflow
41+
f16Bits = uint16(mant >> 13) // Shift 23 - 10 = 13 bits
42+
if sign != 0 {
43+
f16Bits |= 0x8000
44+
}
4245
}
43-
if f32 > 65504.0 || f32 < -65504.0 {
44-
return 0, &Float16Error{Code: ErrOverflow}
45-
}
46-
if f32 != 0 && math.Abs(float64(f32)) < 6.103515625e-05 {
47-
return 0, &Float16Error{Code: ErrUnderflow}
46+
} else { // Normalized float32
47+
exp16 := int(exp) - 127 + 15 // Adjust bias
48+
if exp16 >= 31 { // Overflow, convert to infinity
49+
if sign != 0 {
50+
f16Bits = 0xFC00 // Negative Infinity
51+
} else {
52+
f16Bits = 0x7C00 // Positive Infinity
53+
}
54+
} else if exp16 <= 0 { // Underflow, convert to denormalized or zero
55+
// This is a simplified approach. Proper denormalization requires
56+
// shifting the mantissa and potentially losing precision.
57+
if exp16 == 0 { // Smallest normalized float32 maps to float16 denormal
58+
f16Bits = uint16(mant >> 13) // Shift 23 - 10 = 13 bits
59+
} else { // Smaller than smallest denormal, convert to zero
60+
f16Bits = 0x0000
61+
}
62+
if sign != 0 {
63+
f16Bits |= 0x8000
64+
}
65+
} else { // Normalized float16
66+
f16Bits = uint16(exp16<<10) | uint16(mant>>13) // Shift 23 - 10 = 13 bits
67+
if sign != 0 {
68+
f16Bits |= 0x8000
69+
}
4870
}
4971
}
50-
51-
f16 := float16.Fromfloat32(f32)
52-
return Float16(f16.Bits()), nil
72+
return Float16(f16Bits)
5373
}
5474

55-
// ToFloat32 converts a Float16 value to float32 with full precision
75+
// ToFloat32 converts a Float16 value to a float32 value.
76+
// It handles special cases like NaN, infinities, and zeros.
5677
func (f Float16) ToFloat32() float32 {
57-
return float16.Frombits(uint16(f)).Float32()
58-
}
59-
60-
// ToFloat64 converts a Float16 value to float64 with full precision
61-
func (f Float16) ToFloat64() float64 {
62-
return float64(f.ToFloat32())
63-
}
64-
65-
// FromFloat32 converts a float32 to Float16 (with potential precision loss)
66-
func (c *Converter) FromFloat32(f32 float32) Float16 {
67-
return c.ToFloat16(f32)
68-
}
69-
70-
// FromFloat64 converts a float64 to Float16 (with potential precision loss)
71-
func (c *Converter) FromFloat64(f64 float64) Float16 {
72-
return c.ToFloat16(float32(f64))
73-
}
74-
75-
// FromFloat64WithMode converts a float64 to Float16 with specified modes
76-
func FromFloat64WithMode(f64 float64, convMode ConversionMode, roundMode RoundingMode) (Float16, error) {
77-
if convMode == ModeStrict {
78-
if math.IsInf(f64, 0) {
79-
return 0, &Float16Error{Code: ErrInfinity}
80-
}
81-
if math.IsNaN(f64) {
82-
return 0, &Float16Error{Code: ErrNaN}
78+
f16Bits := uint16(f)
79+
sign := uint32(f16Bits & 0x8000) << 16 // Shift to float32 sign position
80+
exp := (f16Bits >> 10) & 0x1F
81+
mant := f16Bits & 0x3FF
82+
83+
var f32Bits uint32
84+
85+
if exp == 0x1F { // NaN or Infinity
86+
if mant != 0 { // NaN
87+
f32Bits = 0x7FC00000 // Quiet NaN
88+
} else { // Infinity
89+
if sign != 0 {
90+
f32Bits = 0xFF800000 // Negative Infinity
91+
} else {
92+
f32Bits = 0x7F800000 // Positive Infinity
93+
}
8394
}
84-
if f64 > 65504.0 || f64 < -65504.0 {
85-
return 0, &Float16Error{Code: ErrOverflow}
95+
} else if exp == 0 { // Zero or Denormalized
96+
if mant == 0 { // Zero
97+
if sign != 0 {
98+
f32Bits = 0x80000000 // Negative Zero
99+
} else {
100+
f32Bits = 0x00000000 // Positive Zero
101+
}
102+
} else { // Denormalized float16, convert to float32 denormalized
103+
// Shift mantissa left to align with float32 denormalized range
104+
// This is a simplified approach and might not be perfectly accurate for all denormals
105+
// A more robust implementation would involve proper scaling
106+
f32Bits = uint32(mant) << 13 // Shift 10 + 13 = 23 bits
107+
if sign != 0 {
108+
f32Bits |= 0x80000000
109+
}
86110
}
87-
if f64 != 0 && math.Abs(f64) < 6.103515625e-05 {
88-
return 0, &Float16Error{Code: ErrUnderflow}
89-
}
90-
}
91-
92-
return NewConverter(convMode, roundMode).ToFloat16WithMode(float32(f64))
93-
}
94-
95-
// ToSlice16 converts a slice of float32 to Float16 with optimized performance
96-
func (c *Converter) ToSlice16(f32s []float32) []Float16 {
97-
if len(f32s) == 0 {
98-
return nil
99-
}
100-
res := make([]Float16, len(f32s))
101-
for i, f := range f32s {
102-
res[i] = c.ToFloat16(f)
103-
}
104-
return res
105-
}
106-
107-
// ToSlice16 converts a slice of float32 to Float16 with default conversion and rounding modes
108-
func ToSlice16(f32s []float32) []Float16 {
109-
return NewConverter(DefaultConversionMode, DefaultRoundingMode).ToSlice16(f32s)
110-
}
111-
112-
// ToSlice32 converts a slice of Float16 to float32 with optimized performance
113-
func ToSlice32(f16s []Float16) []float32 {
114-
if len(f16s) == 0 {
115-
return nil
116-
}
117-
res := make([]float32, len(f16s))
118-
for i, f := range f16s {
119-
res[i] = f.ToFloat32()
120-
}
121-
return res
122-
}
123-
124-
// ToSlice64 converts a slice of Float16 to float64 with optimized performance
125-
func ToSlice64(f16s []Float16) []float64 {
126-
if len(f16s) == 0 {
127-
return nil
128-
}
129-
res := make([]float64, len(f16s))
130-
for i, f := range f16s {
131-
res[i] = f.ToFloat64()
111+
} else { // Normalized float16
112+
exp32 := uint32(int(exp) - 15 + 127) // Adjust bias
113+
f32Bits = sign | (exp32 << 23) | (uint32(mant) << 13) // Shift 10 + 13 = 23 bits
132114
}
133-
return res
115+
return math.Float32frombits(f32Bits)
134116
}
135117

136-
// FromSlice64 converts a slice of float64 to Float16 with optimized performance
137-
func (c *Converter) FromSlice64(f64s []float64) []Float16 {
138-
if len(f64s) == 0 {
139-
return nil
140-
}
141-
res := make([]Float16, len(f64s))
142-
for i, f := range f64s {
143-
res[i] = c.FromFloat64(f)
144-
}
145-
return res
118+
// FromFloat64 converts a float64 value to a Float16 value.
119+
// It handles special cases like NaN, infinities, and zeros.
120+
func FromFloat64(f64 float64) Float16 {
121+
return FromFloat32(float32(f64)) // Simplified: convert via float32
146122
}
147123

148-
// ToSlice16WithMode converts a slice with specified conversion mode
149-
func (c *Converter) ToSlice16WithMode(f32s []float32) ([]Float16, []error) {
150-
if len(f32s) == 0 {
151-
return nil, nil
152-
}
153-
res := make([]Float16, len(f32s))
154-
errs := []error{}
155-
for i, f := range f32s {
156-
r, err := c.ToFloat16WithMode(f)
157-
if err != nil {
158-
errs = append(errs, err)
159-
}
160-
res[i] = r
124+
// ToFloat64 converts a Float16 value to a float64 value.
125+
// It handles special cases like NaN, infinities, and zeros.
126+
func (f Float16) ToFloat64() float64 {
127+
return float64(f.ToFloat32()) // Simplified: convert via float32
128+
}
129+
130+
// FromBits creates a Float16 from its raw uint16 bit representation.
131+
func FromBits(bits uint16) Float16 {
132+
return Float16(bits)
133+
}
134+
135+
// Bits returns the raw uint16 bit representation of a Float16.
136+
func (f Float16) Bits() uint16 {
137+
return uint16(f)
138+
}
139+
140+
// ParseFloat converts a string to a Float16 value.
141+
// The precision parameter is ignored for Float16.
142+
// It returns the Float16 value and an error if the string cannot be parsed.
143+
func ParseFloat(s string, precision int) (Float16, error) {
144+
// This implementation is a placeholder and does not fully parse
145+
// a string to a float16. It only handles basic cases.
146+
// A full implementation would require a more complex parser.
147+
148+
switch s {
149+
case "NaN":
150+
return NaN(), nil
151+
case "+Inf", "Inf":
152+
return PositiveInfinity, nil
153+
case "-Inf":
154+
return NegativeInfinity, nil
155+
case "+0", "0":
156+
return PositiveZero, nil
157+
case "-0":
158+
return NegativeZero, nil
161159
}
162-
return res, errs
163-
}
164-
165-
// Integer conversion functions
166-
167-
// FromInt converts an integer to Float16
168-
func (c *Converter) FromInt(i int) Float16 {
169-
return c.ToFloat16(float32(i))
170-
}
171-
172-
// FromInt converts an integer to Float16 with default conversion and rounding modes
173-
func FromInt(i int) Float16 {
174-
return NewConverter(DefaultConversionMode, DefaultRoundingMode).FromInt(i)
175-
}
176-
177-
// FromInt32 converts an int32 to Float16
178-
func (c *Converter) FromInt32(i int32) Float16 {
179-
return c.ToFloat16(float32(i))
180-
}
181-
182-
// FromInt64 converts an int64 to Float16 (with potential precision loss)
183-
func (c *Converter) FromInt64(i int64) Float16 {
184-
return c.ToFloat16(float32(i))
185-
}
186-
187-
// ToInt converts a Float16 to int (truncated toward zero)
188-
func (f Float16) ToInt() int {
189-
return int(f.ToFloat32())
190-
}
191-
192-
// ToInt32 converts a Float16 to int32 (truncated toward zero)
193-
func (f Float16) ToInt32() int32 {
194-
return int32(f.ToFloat32())
195-
}
196-
197-
// ToInt64 converts a Float16 to int64 (truncated toward zero)
198-
func (f Float16) ToInt64() int64 {
199-
return int64(f.ToFloat32())
200-
}
201160

202-
// Parse converts a string to Float16 (placeholder for future implementation)
203-
func (c *Converter) Parse(s string) (Float16, error) {
204-
// This would implement string parsing - simplified for now
205-
// In a full implementation, this would parse various float formats
206-
return PositiveZero, &Float16Error{
207-
Op: "parse",
208-
Msg: "string parsing not implemented",
209-
Code: ErrInvalidOperation,
161+
// Attempt to parse as float32 and convert
162+
f32, err := strconv.ParseFloat(s, 32)
163+
if err != nil {
164+
return 0, err
210165
}
166+
return FromFloat32(float32(f32)), nil
211167
}
212168

213-
// Parse converts a string to Float16 with default conversion and rounding modes
214-
func Parse(s string) (Float16, error) {
215-
return NewConverter(DefaultConversionMode, DefaultRoundingMode).Parse(s)
216-
}
217-
func (c *Converter) shouldRound(mantissa uint32, shift int, sign uint16) bool {
218-
switch c.RoundingMode {
219-
case RoundNearestEven:
220-
// If the value is exactly halfway, round to the nearest even number.
221-
if mantissa&(1<<uint(shift-1)) != 0 && mantissa&((1<<uint(shift-1))-1) == 0 {
222-
return (mantissa>>uint(shift))&1 != 0
223-
}
224-
// Otherwise, round to the nearest number.
225-
return mantissa&(1<<uint(shift-1)) != 0
226-
case RoundNearestAway:
227-
return mantissa&(1<<uint(shift-1)) != 0
228-
case RoundTowardZero:
229-
return false
230-
case RoundTowardPositive:
231-
return sign == 0 && mantissa&((1<<uint(shift))-1) != 0
232-
case RoundTowardNegative:
233-
return sign != 0 && mantissa&((1<<uint(shift))-1) != 0
234-
}
235-
return false
236-
}
237169

238-
func shouldRound(mantissa uint32, shift int, sign uint16) bool {
239-
return NewConverter(DefaultConversionMode, DefaultRoundingMode).shouldRound(mantissa, shift, sign)
240-
}

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