1 // run 2 3 // Copyright 2016 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 // This test checks if the compiler's internal constant 8 // arithmetic correctly rounds denormal float32 values. 9 10 package main 11 12 import ( 13 "fmt" 14 "math" 15 ) 16 17 func main() { 18 for _, t := range []struct { 19 value float32 20 bits uint32 21 }{ 22 {0e+00, 0x00000000}, 23 {1e-46, 0x00000000}, 24 {0.5e-45, 0x00000000}, 25 {0.8e-45, 0x00000001}, 26 {1e-45, 0x00000001}, 27 {2e-45, 0x00000001}, 28 {3e-45, 0x00000002}, 29 {4e-45, 0x00000003}, 30 {5e-45, 0x00000004}, 31 {6e-45, 0x00000004}, 32 {7e-45, 0x00000005}, 33 {8e-45, 0x00000006}, 34 {9e-45, 0x00000006}, 35 {1.0e-44, 0x00000007}, 36 {1.1e-44, 0x00000008}, 37 {1.2e-44, 0x00000009}, 38 } { 39 got := math.Float32bits(t.value) 40 want := t.bits 41 if got != want { 42 panic(fmt.Sprintf("bits(%g) = 0x%08x; want 0x%08x", t.value, got, want)) 43 } 44 } 45 } 46
