bug447.go

     1  // runoutput
     2  
     3  // Copyright 2012 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  // Issue 3804
     8  // test all possible float -> integer conversions
     9  
    10  package main
    11  
    12  import (
    13  	"bytes"
    14  	"fmt"
    15  	"strings"
    16  )
    17  
    18  var (
    19  	intWidths = []int{8, 16, 32, 64} // int%d and uint%d
    20  	floatWidths = []int{32, 64} // float%d
    21  )
    22  
    23  func main() {
    24  
    25  	var names, funcs bytes.Buffer
    26  
    27  	for _, iWidth := range intWidths {
    28  		for _, typ := range []string{"int", "uint"} {
    29  			var segs bytes.Buffer
    30  			itype := fmt.Sprintf("%s%d", typ, iWidth)
    31  			names.WriteString("\ttest" + itype + ",\n")
    32  			for _, fWidth := range floatWidths {
    33  				ftype := fmt.Sprintf("float%d", fWidth)
    34  				seg := strings.Replace(testSegment, "$F", ftype, -1)
    35  				seg = strings.Replace(seg, "$I", itype, -1)
    36  				segs.WriteString(seg)
    37  			}
    38  			body := strings.Replace(testFunc, "$I", itype, -1)
    39  			if typ[0] == 'u' {
    40  				body = strings.Replace(body, "$TEST", " || i < 0", 1)
    41  			} else {
    42  				body = strings.Replace(body, "$TEST", "", 1)
    43  			}
    44  			body = strings.Replace(body, "$TESTSEGMENTS", segs.String(), 1)
    45  			funcs.WriteString(body)
    46  		}
    47  	}
    48  
    49  	program = strings.Replace(program, "$NAMES", names.String(), 1)
    50  	program = strings.Replace(program, "$FUNCS", funcs.String(), 1)
    51  	fmt.Print(program)
    52  }
    53  
    54  const testSegment = `
    55  	f$F := $F(f)
    56  	if math.Abs(float64(f$F) - f) < 0.05 {
    57  		if v := $I(f$F); v != $I(i) {
    58  			fmt.Printf("$I($F(%f)) = %v, expected %v\n", f, v, i)
    59  		}
    60  	}`
    61  
    62  const testFunc =
    63  `func test$I(f float64, i int64) {
    64  	if i != int64($I(i))$TEST {
    65  		return
    66  	}
    67  $TESTSEGMENTS
    68  }
    69  `
    70  
    71  var program =
    72  `package main
    73  
    74  import (
    75  	"fmt"
    76  	"math"
    77  )
    78  
    79  var tests = []struct {
    80  	f float64
    81  	i int64
    82  }{
    83  	{39.7, 39},
    84  	{-39.7, -39},
    85  	{258.6, 258},
    86  	{-258.6, -258},
    87  	{65538.9, 65538},
    88  	{-65538.9, -65538},
    89  	{4294967298.8, 4294967298},
    90  	{-4294967298.8, -4294967298},
    91  }
    92  
    93  var funcs = []func(float64, int64){
    94  $NAMES
    95  }
    96  
    97  $FUNCS
    98  func main() {
    99  	for _, t := range tests {
   100  		for _, f := range funcs {
   101  			f(t.f, t.i)
   102  		}
   103  	}
   104  }
   105  `
   106
View as plain text