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  // TODO: This test probably should be in a different place.
    15  
    16  func TestFloatTruncation(t *testing.T) {
    17  	testdata := []struct {
    18  		input      float64
    19  		convInt64  int64
    20  		convUInt64 uint64
    21  		overflow   bool
    22  	}{
    23  		// max +- 1
    24  		{
    25  			input:      0x7fffffffffffffff,
    26  			convInt64:  0x7fffffffffffffff,
    27  			convUInt64: 0x8000000000000000,
    28  		},
    29  		// For out-of-bounds conversion, the result is implementation-dependent.
    30  		// This test verifies the implementation of wasm architecture, which is,
    31  		// saturating to the min/max value.
    32  		{
    33  			input:      0x8000000000000000,
    34  			convInt64:  0x7fffffffffffffff,
    35  			convUInt64: 0x8000000000000000,
    36  		},
    37  		{
    38  			input:      0x7ffffffffffffffe,
    39  			convInt64:  0x7fffffffffffffff,
    40  			convUInt64: 0x8000000000000000,
    41  		},
    42  		// neg max +- 1
    43  		{
    44  			input:      -0x8000000000000000,
    45  			convInt64:  -0x8000000000000000,
    46  			convUInt64: 0,
    47  		},
    48  		{
    49  			input:      -0x8000000000000001,
    50  			convInt64:  -0x8000000000000000,
    51  			convUInt64: 0,
    52  		},
    53  		{
    54  			input:      -0x7fffffffffffffff,
    55  			convInt64:  -0x8000000000000000,
    56  			convUInt64: 0,
    57  		},
    58  		// trunc point +- 1
    59  		{
    60  			input:      0x7ffffffffffffdff,
    61  			convInt64:  0x7ffffffffffffc00,
    62  			convUInt64: 0x7ffffffffffffc00,
    63  		},
    64  		{
    65  			input:      0x7ffffffffffffe00,
    66  			convInt64:  0x7fffffffffffffff,
    67  			convUInt64: 0x8000000000000000,
    68  		},
    69  		{
    70  			input:      0x7ffffffffffffdfe,
    71  			convInt64:  0x7ffffffffffffc00,
    72  			convUInt64: 0x7ffffffffffffc00,
    73  		},
    74  		// neg trunc point +- 1
    75  		{
    76  			input:      -0x7ffffffffffffdff,
    77  			convInt64:  -0x7ffffffffffffc00,
    78  			convUInt64: 0,
    79  		},
    80  		{
    81  			input:      -0x7ffffffffffffe00,
    82  			convInt64:  -0x8000000000000000,
    83  			convUInt64: 0,
    84  		},
    85  		{
    86  			input:      -0x7ffffffffffffdfe,
    87  			convInt64:  -0x7ffffffffffffc00,
    88  			convUInt64: 0,
    89  		},
    90  		// umax +- 1
    91  		{
    92  			input:      0xffffffffffffffff,
    93  			convInt64:  0x7fffffffffffffff,
    94  			convUInt64: 0xffffffffffffffff,
    95  		},
    96  		{
    97  			input:      0x10000000000000000,
    98  			convInt64:  0x7fffffffffffffff,
    99  			convUInt64: 0xffffffffffffffff,
   100  		},
   101  		{
   102  			input:      0xfffffffffffffffe,
   103  			convInt64:  0x7fffffffffffffff,
   104  			convUInt64: 0xffffffffffffffff,
   105  		},
   106  		// umax trunc +- 1
   107  		{
   108  			input:      0xfffffffffffffbff,
   109  			convInt64:  0x7fffffffffffffff,
   110  			convUInt64: 0xfffffffffffff800,
   111  		},
   112  		{
   113  			input:      0xfffffffffffffc00,
   114  			convInt64:  0x7fffffffffffffff,
   115  			convUInt64: 0xffffffffffffffff,
   116  		},
   117  		{
   118  			input:      0xfffffffffffffbfe,
   119  			convInt64:  0x7fffffffffffffff,
   120  			convUInt64: 0xfffffffffffff800,
   121  		},
   122  	}
   123  	for _, item := range testdata {
   124  		if got, want := int64(item.input), item.convInt64; got != want {
   125  			t.Errorf("int64(%f): got %x, want %x", item.input, got, want)
   126  		}
   127  		if got, want := uint64(item.input), item.convUInt64; got != want {
   128  			t.Errorf("uint64(%f): got %x, want %x", item.input, got, want)
   129  		}
   130  	}
   131  }
   132
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