diff --git a/src/pkg/reflect/all_test.go b/src/pkg/reflect/all_test.go index 842b507507..4ebe055305 100644 --- a/src/pkg/reflect/all_test.go +++ b/src/pkg/reflect/all_test.go @@ -2664,6 +2664,45 @@ func TestConvert(t *testing.T) { } } +func TestOverflow(t *testing.T) { + if ovf := V(float64(0)).OverflowFloat(1e300); ovf { + t.Errorf("%v wrongly overflows float64", 1e300) + } + + maxFloat32 := float64((1<<24 - 1) << (127 - 23)) + if ovf := V(float32(0)).OverflowFloat(maxFloat32); ovf { + t.Errorf("%v wrongly overflows float32", maxFloat32) + } + ovfFloat32 := float64((1<<24-1)<<(127-23) + 1<<(127-52)) + if ovf := V(float32(0)).OverflowFloat(ovfFloat32); !ovf { + t.Errorf("%v should overflow float32", ovfFloat32) + } + if ovf := V(float32(0)).OverflowFloat(-ovfFloat32); !ovf { + t.Errorf("%v should overflow float32", -ovfFloat32) + } + + maxInt32 := int64(0x7fffffff) + if ovf := V(int32(0)).OverflowInt(maxInt32); ovf { + t.Errorf("%v wrongly overflows int32", maxInt32) + } + if ovf := V(int32(0)).OverflowInt(-1 << 31); ovf { + t.Errorf("%v wrongly overflows int32", -int64(1)<<31) + } + ovfInt32 := int64(1 << 31) + if ovf := V(int32(0)).OverflowInt(ovfInt32); !ovf { + t.Errorf("%v should overflow int32", ovfInt32) + } + + maxUint32 := uint64(0xffffffff) + if ovf := V(uint32(0)).OverflowUint(maxUint32); ovf { + t.Errorf("%v wrongly overflows uint32", maxUint32) + } + ovfUint32 := uint64(1 << 32) + if ovf := V(uint32(0)).OverflowUint(ovfUint32); !ovf { + t.Errorf("%v should overflow uint32", ovfUint32) + } +} + type B1 struct { X int Y int diff --git a/src/pkg/reflect/value.go b/src/pkg/reflect/value.go index be5d03504e..2d217a5180 100644 --- a/src/pkg/reflect/value.go +++ b/src/pkg/reflect/value.go @@ -1179,7 +1179,7 @@ func overflowFloat32(x float64) bool { if x < 0 { x = -x } - return math.MaxFloat32 <= x && x <= math.MaxFloat64 + return math.MaxFloat32 < x && x <= math.MaxFloat64 } // OverflowInt returns true if the int64 x cannot be represented by v's type.