gitee.com/quant1x/gox@v1.21.2/encoding/binary/struc/custom_float16_test.go (about)

     1  package struc
     2  
     3  import (
     4  	"bytes"
     5  	"encoding/binary"
     6  	"fmt"
     7  	"math"
     8  	"strconv"
     9  	"strings"
    10  	"testing"
    11  )
    12  
    13  func TestFloat16(t *testing.T) {
    14  	// test cases from https://en.wikipedia.org/wiki/Half-precision_floating-point_format#Half_precision_examples
    15  	tests := []struct {
    16  		B string
    17  		F float64
    18  	}{
    19  		//s expnt significand
    20  		{"0 01111 0000000000", 1},
    21  		{"0 01111 0000000001", 1.0009765625},
    22  		{"1 10000 0000000000", -2},
    23  		{"0 11110 1111111111", 65504},
    24  		// {"0 00001 0000000000", 0.0000610352},
    25  		// {"0 00000 1111111111", 0.0000609756},
    26  		// {"0 00000 0000000001", 0.0000000596046},
    27  		{"0 00000 0000000000", 0},
    28  		// {"1 00000 0000000000", -0},
    29  		{"0 11111 0000000000", math.Inf(1)},
    30  		{"1 11111 0000000000", math.Inf(-1)},
    31  		{"0 01101 0101010101", 0.333251953125},
    32  	}
    33  	for _, test := range tests {
    34  		var buf bytes.Buffer
    35  		f := Float16(test.F)
    36  		if err := Pack(&buf, &f); err != nil {
    37  			t.Error("pack failed:", err)
    38  			continue
    39  		}
    40  		bitval, _ := strconv.ParseUint(strings.Replace(test.B, " ", "", -1), 2, 16)
    41  		tmp := binary.BigEndian.Uint16(buf.Bytes())
    42  		if tmp != uint16(bitval) {
    43  			t.Errorf("incorrect pack: %s != %016b (%f)", test.B, tmp, test.F)
    44  			continue
    45  		}
    46  		var f2 Float16
    47  		if err := Unpack(&buf, &f2); err != nil {
    48  			t.Error("unpack failed:", err)
    49  			continue
    50  		}
    51  		// let sprintf deal with (im)precision for me here
    52  		if fmt.Sprintf("%f", f) != fmt.Sprintf("%f", f2) {
    53  			t.Errorf("incorrect unpack: %016b %f != %f", bitval, f, f2)
    54  		}
    55  	}
    56  }