1 files changed, 66 insertions, 0 deletions
diff --git a/test/fixedbugs/issue12577.go b/test/fixedbugs/issue12577.go
new file mode 100644
index 0000000..249b4f2
--- /dev/null
+++ b/test/fixedbugs/issue12577.go
@@ -0,0 +1,66 @@
+// 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)
+}