github.com/tidwall/go@v0.0.0-20170415222209-6694a6888b7d/src/cmd/compile/internal/gc/testdata/sqrt_const.go (about)

     1  // Copyright 2016 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package main
     6  
     7  import (
     8  	"fmt"
     9  	"math"
    10  )
    11  
    12  var tests = [...]struct {
    13  	name string
    14  	in   float64 // used for error messages, not an input
    15  	got  float64
    16  	want float64
    17  }{
    18  	{"sqrt0", 0, math.Sqrt(0), 0},
    19  	{"sqrt1", 1, math.Sqrt(1), 1},
    20  	{"sqrt2", 2, math.Sqrt(2), math.Sqrt2},
    21  	{"sqrt4", 4, math.Sqrt(4), 2},
    22  	{"sqrt100", 100, math.Sqrt(100), 10},
    23  	{"sqrt101", 101, math.Sqrt(101), 10.04987562112089},
    24  }
    25  
    26  var nanTests = [...]struct {
    27  	name string
    28  	in   float64 // used for error messages, not an input
    29  	got  float64
    30  }{
    31  	{"sqrtNaN", math.NaN(), math.Sqrt(math.NaN())},
    32  	{"sqrtNegative", -1, math.Sqrt(-1)},
    33  	{"sqrtNegInf", math.Inf(-1), math.Sqrt(math.Inf(-1))},
    34  }
    35  
    36  var failed = false
    37  
    38  func main() {
    39  	for _, test := range tests {
    40  		if test.got != test.want {
    41  			fmt.Printf("%s: math.Sqrt(%f): got %f, want %f\n", test.name, test.in, test.got, test.want)
    42  			failed = true
    43  		}
    44  	}
    45  	for _, test := range nanTests {
    46  		if math.IsNaN(test.got) != true {
    47  			fmt.Printf("%s: math.Sqrt(%f): got %f, want NaN\n", test.name, test.in, test.got)
    48  			failed = true
    49  		}
    50  	}
    51  	if got := math.Sqrt(math.Inf(1)); !math.IsInf(got, 1) {
    52  		fmt.Printf("math.Sqrt(+Inf), got %f, want +Inf\n", got)
    53  		failed = true
    54  	}
    55  
    56  	if failed {
    57  		panic("failed")
    58  	}
    59  }