gcc/libgo/go/math/nextafter.go
Ian Lance Taylor 7a9389330e Add Go frontend, libgo library, and Go testsuite.
gcc/:
	* gcc.c (default_compilers): Add entry for ".go".
	* common.opt: Add -static-libgo as a driver option.
	* doc/install.texi (Configuration): Mention libgo as an option for
	--enable-shared.  Mention go as an option for --enable-languages.
	* doc/invoke.texi (Overall Options): Mention .go as a file name
	suffix.  Mention go as a -x option.
	* doc/frontends.texi (G++ and GCC): Mention Go as a supported
	language.
	* doc/sourcebuild.texi (Top Level): Mention libgo.
	* doc/standards.texi (Standards): Add section on Go language.
	Move references for other languages into their own section.
	* doc/contrib.texi (Contributors): Mention that I contributed the
	Go frontend.
gcc/testsuite/:
	* lib/go.exp: New file.
	* lib/go-dg.exp: New file.
	* lib/go-torture.exp: New file.
	* lib/target-supports.exp (check_compile): Match // Go.

From-SVN: r167407
2010-12-03 04:34:57 +00:00

30 lines
775 B
Go

// Copyright 2010 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 math
// Nextafter returns the next representable value after x towards y.
// If x == y, then x is returned.
//
// Special cases are:
// Nextafter(NaN, y) = NaN
// Nextafter(x, NaN) = NaN
func Nextafter(x, y float64) (r float64) {
// TODO(rsc): Remove manual inlining of IsNaN
// when compiler does it for us
switch {
case x != x || y != y: // IsNaN(x) || IsNaN(y): // special case
r = NaN()
case x == y:
r = x
case x == 0:
r = Copysign(Float64frombits(1), y)
case (y > x) == (x > 0):
r = Float64frombits(Float64bits(x) + 1)
default:
r = Float64frombits(Float64bits(x) - 1)
}
return r
}