go/test/fixedbugs/issue12577.go
Robert Griesemer 76285213b8 cmd/compile/internal/gc: there are no -0 floating-point constants
Fixes #12577.

Change-Id: Id469cd92f5f9436b0ef948ee1a252ed1842bc7aa
Reviewed-on: https://go-review.googlesource.com/16133
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2015-10-20 22:11:11 +00:00

66 lines
1,011 B
Go

// run
// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Issue 12577: Test that there are no -0 floating-point constants.
package main
import "math"
const (
z0 = 0.0
z1 = -0.0
z2 = -z0
z3 = -z2
)
var (
x0 float32 = z0
x1 float32 = z1
x2 float32 = z2
x3 float32 = z3
y0 float64 = z0
y1 float64 = z1
y2 float64 = z2
y3 float64 = z3
)
func test32(f float32) {
if f != 0 || math.Signbit(float64(f)) {
println("BUG: got", f, "want 0.0")
return
}
}
func test64(f float64) {
if f != 0 || math.Signbit(f) {
println("BUG: got", f, "want 0.0")
return
}
}
func main() {
if f := -x0; f != 0 || !math.Signbit(float64(f)) {
println("BUG: got", f, "want -0.0")
}
test32(-0.0)
test32(x0)
test32(x1)
test32(x2)
test32(x3)
if f := -y0; f != 0 || !math.Signbit(f) {
println("BUG: got", f, "want -0.0")
}
test64(-0.0)
test64(y0)
test64(y1)
test64(y2)
test64(y3)
}