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go/test/float_lit3.go
Emmanuel Odeke 53fd522c0d all: make copyright headers consistent with one space after period
Follows suit with https://go-review.googlesource.com/#/c/20111.

Generated by running
$ grep -R 'Go Authors.  All' * | cut -d":" -f1 | while read F;do perl -pi -e 's/Go
Authors.  All/Go Authors. All/g' $F;done

The code in cmd/internal/unvendor wasn't changed.

Fixes #15213

Change-Id: I4f235cee0a62ec435f9e8540a1ec08ae03b1a75f
Reviewed-on: https://go-review.googlesource.com/21819
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-02 13:43:18 +00:00

49 lines
1.8 KiB
Go

// errorcheck
// Check flagging of invalid conversion of constant to float32/float64 near min/max boundaries.
// Copyright 2014 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.
package main
// See float_lit2.go for motivation for these values.
const (
two24 = 1.0 * (1 << 24)
two53 = 1.0 * (1 << 53)
two64 = 1.0 * (1 << 64)
two128 = two64 * two64
two256 = two128 * two128
two512 = two256 * two256
two768 = two512 * two256
two1024 = two512 * two512
ulp32 = two128 / two24
max32 = two128 - ulp32
ulp64 = two1024 / two53
max64 = two1024 - ulp64
)
var x = []interface{}{
float32(max32 + ulp32/2 - 1), // ok
float32(max32 + ulp32/2 - two128/two256), // ok
float32(max32 + ulp32/2), // ERROR "constant 3\.40282e\+38 overflows float32"
float32(-max32 - ulp32/2 + 1), // ok
float32(-max32 - ulp32/2 + two128/two256), // ok
float32(-max32 - ulp32/2), // ERROR "constant -3\.40282e\+38 overflows float32"
// If the compiler's internal floating point representation
// is shorter than 1024 bits, it cannot distinguish max64+ulp64/2-1 and max64+ulp64/2.
// gc uses fewer than 1024 bits, so allow it to print the overflow error for the -1 case.
float64(max64 + ulp64/2 - two1024/two256), // ok
float64(max64 + ulp64/2 - 1), // GC_ERROR "constant 1\.79769e\+308 overflows float64"
float64(max64 + ulp64/2), // ERROR "constant 1\.79769e\+308 overflows float64"
float64(-max64 - ulp64/2 + two1024/two256), // ok
float64(-max64 - ulp64/2 + 1), // GC_ERROR "constant -1\.79769e\+308 overflows float64"
float64(-max64 - ulp64/2), // ERROR "constant -1\.79769e\+308 overflows float64"
}