conv_wasm_test.go

     1  // Copyright 2020 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 runtime_test
     6  
     7  import (
     8  	"testing"
     9  )
    10  
    11  var res int64
    12  var ures uint64
    13  
    14  func TestFloatTruncation(t *testing.T) {
    15  	testdata := []struct {
    16  		input      float64
    17  		convInt64  int64
    18  		convUInt64 uint64
    19  		overflow   bool
    20  	}{
    21  		// max +- 1
    22  		{
    23  			input:      0x7fffffffffffffff,
    24  			convInt64:  -0x8000000000000000,
    25  			convUInt64: 0x8000000000000000,
    26  		},
    27  		// For out-of-bounds conversion, the result is implementation-dependent.
    28  		// This test verifies the implementation of wasm architecture.
    29  		{
    30  			input:      0x8000000000000000,
    31  			convInt64:  -0x8000000000000000,
    32  			convUInt64: 0x8000000000000000,
    33  		},
    34  		{
    35  			input:      0x7ffffffffffffffe,
    36  			convInt64:  -0x8000000000000000,
    37  			convUInt64: 0x8000000000000000,
    38  		},
    39  		// neg max +- 1
    40  		{
    41  			input:      -0x8000000000000000,
    42  			convInt64:  -0x8000000000000000,
    43  			convUInt64: 0x8000000000000000,
    44  		},
    45  		{
    46  			input:      -0x8000000000000001,
    47  			convInt64:  -0x8000000000000000,
    48  			convUInt64: 0x8000000000000000,
    49  		},
    50  		{
    51  			input:      -0x7fffffffffffffff,
    52  			convInt64:  -0x8000000000000000,
    53  			convUInt64: 0x8000000000000000,
    54  		},
    55  		// trunc point +- 1
    56  		{
    57  			input:      0x7ffffffffffffdff,
    58  			convInt64:  0x7ffffffffffffc00,
    59  			convUInt64: 0x7ffffffffffffc00,
    60  		},
    61  		{
    62  			input:      0x7ffffffffffffe00,
    63  			convInt64:  -0x8000000000000000,
    64  			convUInt64: 0x8000000000000000,
    65  		},
    66  		{
    67  			input:      0x7ffffffffffffdfe,
    68  			convInt64:  0x7ffffffffffffc00,
    69  			convUInt64: 0x7ffffffffffffc00,
    70  		},
    71  		// neg trunc point +- 1
    72  		{
    73  			input:      -0x7ffffffffffffdff,
    74  			convInt64:  -0x7ffffffffffffc00,
    75  			convUInt64: 0x8000000000000000,
    76  		},
    77  		{
    78  			input:      -0x7ffffffffffffe00,
    79  			convInt64:  -0x8000000000000000,
    80  			convUInt64: 0x8000000000000000,
    81  		},
    82  		{
    83  			input:      -0x7ffffffffffffdfe,
    84  			convInt64:  -0x7ffffffffffffc00,
    85  			convUInt64: 0x8000000000000000,
    86  		},
    87  		// umax +- 1
    88  		{
    89  			input:      0xffffffffffffffff,
    90  			convInt64:  -0x8000000000000000,
    91  			convUInt64: 0x8000000000000000,
    92  		},
    93  		{
    94  			input:      0x10000000000000000,
    95  			convInt64:  -0x8000000000000000,
    96  			convUInt64: 0x8000000000000000,
    97  		},
    98  		{
    99  			input:      0xfffffffffffffffe,
   100  			convInt64:  -0x8000000000000000,
   101  			convUInt64: 0x8000000000000000,
   102  		},
   103  		// umax trunc +- 1
   104  		{
   105  			input:      0xfffffffffffffbff,
   106  			convInt64:  -0x8000000000000000,
   107  			convUInt64: 0xfffffffffffff800,
   108  		},
   109  		{
   110  			input:      0xfffffffffffffc00,
   111  			convInt64:  -0x8000000000000000,
   112  			convUInt64: 0x8000000000000000,
   113  		},
   114  		{
   115  			input:      0xfffffffffffffbfe,
   116  			convInt64:  -0x8000000000000000,
   117  			convUInt64: 0xfffffffffffff800,
   118  		},
   119  	}
   120  	for _, item := range testdata {
   121  		if got, want := int64(item.input), item.convInt64; got != want {
   122  			t.Errorf("int64(%f): got %x, want %x", item.input, got, want)
   123  		}
   124  		if got, want := uint64(item.input), item.convUInt64; got != want {
   125  			t.Errorf("uint64(%f): got %x, want %x", item.input, got, want)
   126  		}
   127  	}
   128  }
   129
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