github.com/mdempsky/go@v0.0.0-20151201204031-5dd372bd1e70/test/floatcmp.go (about)

     1  // run
     2  
     3  // Copyright 2009 The Go Authors. All rights reserved.
     4  // Use of this source code is governed by a BSD-style
     5  // license that can be found in the LICENSE file.
     6  
     7  // Test floating-point comparison involving NaN.
     8  
     9  package main
    10  
    11  import "math"
    12  
    13  type floatTest struct {
    14  	name string
    15  	expr bool
    16  	want bool
    17  }
    18  
    19  var nan float64 = math.NaN()
    20  var f float64 = 1
    21  
    22  var tests = []floatTest{
    23  	floatTest{"nan == nan", nan == nan, false},
    24  	floatTest{"nan != nan", nan != nan, true},
    25  	floatTest{"nan < nan", nan < nan, false},
    26  	floatTest{"nan > nan", nan > nan, false},
    27  	floatTest{"nan <= nan", nan <= nan, false},
    28  	floatTest{"nan >= nan", nan >= nan, false},
    29  	floatTest{"f == nan", f == nan, false},
    30  	floatTest{"f != nan", f != nan, true},
    31  	floatTest{"f < nan", f < nan, false},
    32  	floatTest{"f > nan", f > nan, false},
    33  	floatTest{"f <= nan", f <= nan, false},
    34  	floatTest{"f >= nan", f >= nan, false},
    35  	floatTest{"nan == f", nan == f, false},
    36  	floatTest{"nan != f", nan != f, true},
    37  	floatTest{"nan < f", nan < f, false},
    38  	floatTest{"nan > f", nan > f, false},
    39  	floatTest{"nan <= f", nan <= f, false},
    40  	floatTest{"nan >= f", nan >= f, false},
    41  	floatTest{"!(nan == nan)", !(nan == nan), true},
    42  	floatTest{"!(nan != nan)", !(nan != nan), false},
    43  	floatTest{"!(nan < nan)", !(nan < nan), true},
    44  	floatTest{"!(nan > nan)", !(nan > nan), true},
    45  	floatTest{"!(nan <= nan)", !(nan <= nan), true},
    46  	floatTest{"!(nan >= nan)", !(nan >= nan), true},
    47  	floatTest{"!(f == nan)", !(f == nan), true},
    48  	floatTest{"!(f != nan)", !(f != nan), false},
    49  	floatTest{"!(f < nan)", !(f < nan), true},
    50  	floatTest{"!(f > nan)", !(f > nan), true},
    51  	floatTest{"!(f <= nan)", !(f <= nan), true},
    52  	floatTest{"!(f >= nan)", !(f >= nan), true},
    53  	floatTest{"!(nan == f)", !(nan == f), true},
    54  	floatTest{"!(nan != f)", !(nan != f), false},
    55  	floatTest{"!(nan < f)", !(nan < f), true},
    56  	floatTest{"!(nan > f)", !(nan > f), true},
    57  	floatTest{"!(nan <= f)", !(nan <= f), true},
    58  	floatTest{"!(nan >= f)", !(nan >= f), true},
    59  	floatTest{"!!(nan == nan)", !!(nan == nan), false},
    60  	floatTest{"!!(nan != nan)", !!(nan != nan), true},
    61  	floatTest{"!!(nan < nan)", !!(nan < nan), false},
    62  	floatTest{"!!(nan > nan)", !!(nan > nan), false},
    63  	floatTest{"!!(nan <= nan)", !!(nan <= nan), false},
    64  	floatTest{"!!(nan >= nan)", !!(nan >= nan), false},
    65  	floatTest{"!!(f == nan)", !!(f == nan), false},
    66  	floatTest{"!!(f != nan)", !!(f != nan), true},
    67  	floatTest{"!!(f < nan)", !!(f < nan), false},
    68  	floatTest{"!!(f > nan)", !!(f > nan), false},
    69  	floatTest{"!!(f <= nan)", !!(f <= nan), false},
    70  	floatTest{"!!(f >= nan)", !!(f >= nan), false},
    71  	floatTest{"!!(nan == f)", !!(nan == f), false},
    72  	floatTest{"!!(nan != f)", !!(nan != f), true},
    73  	floatTest{"!!(nan < f)", !!(nan < f), false},
    74  	floatTest{"!!(nan > f)", !!(nan > f), false},
    75  	floatTest{"!!(nan <= f)", !!(nan <= f), false},
    76  	floatTest{"!!(nan >= f)", !!(nan >= f), false},
    77  }
    78  
    79  func main() {
    80  	bad := false
    81  	for _, t := range tests {
    82  		if t.expr != t.want {
    83  			if !bad {
    84  				bad = true
    85  				println("BUG: floatcmp")
    86  			}
    87  			println(t.name, "=", t.expr, "want", t.want)
    88  		}
    89  	}
    90  	if bad {
    91  		panic("floatcmp failed")
    92  	}
    93  }