1 // errorcheck 2 3 // Check flagging of invalid conversion of constant to float32/float64 near min/max boundaries. 4 5 // Copyright 2014 The Go Authors. All rights reserved. 6 // Use of this source code is governed by a BSD-style 7 // license that can be found in the LICENSE file. 8 9 package main 10 11 // See float_lit2.go for motivation for these values. 12 const ( 13 two24 = 1.0 * (1 << 24) 14 two53 = 1.0 * (1 << 53) 15 two64 = 1.0 * (1 << 64) 16 two128 = two64 * two64 17 two256 = two128 * two128 18 two512 = two256 * two256 19 two768 = two512 * two256 20 two1024 = two512 * two512 21 22 ulp32 = two128 / two24 23 max32 = two128 - ulp32 24 25 ulp64 = two1024 / two53 26 max64 = two1024 - ulp64 27 ) 28 29 var x = []interface{}{ 30 float32(max32 + ulp32/2 - 1), // ok 31 float32(max32 + ulp32/2 - two128/two256), // ok 32 float32(max32 + ulp32/2), // ERROR "constant 3\.40282e\+38 overflows float32" 33 34 float32(-max32 - ulp32/2 + 1), // ok 35 float32(-max32 - ulp32/2 + two128/two256), // ok 36 float32(-max32 - ulp32/2), // ERROR "constant -3\.40282e\+38 overflows float32" 37 38 // If the compiler's internal floating point representation 39 // is shorter than 1024 bits, it cannot distinguish max64+ulp64/2-1 and max64+ulp64/2. 40 // gc uses fewer than 1024 bits, so allow it to print the overflow error for the -1 case. 41 float64(max64 + ulp64/2 - two1024/two256), // ok 42 float64(max64 + ulp64/2 - 1), // GC_ERROR "constant 1\.79769e\+308 overflows float64" 43 float64(max64 + ulp64/2), // ERROR "constant 1\.79769e\+308 overflows float64" 44 45 float64(-max64 - ulp64/2 + two1024/two256), // ok 46 float64(-max64 - ulp64/2 + 1), // GC_ERROR "constant -1\.79769e\+308 overflows float64" 47 float64(-max64 - ulp64/2), // ERROR "constant -1\.79769e\+308 overflows float64" 48 } 49
