7a9389330e
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
49 lines
1.5 KiB
Go
49 lines
1.5 KiB
Go
// Copyright 2009 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
|
|
|
|
const (
|
|
uvnan = 0x7FF0000000000001
|
|
uvinf = 0x7FF0000000000000
|
|
uvneginf = 0xFFF0000000000000
|
|
mask = 0x7FF
|
|
shift = 64 - 11 - 1
|
|
bias = 1022
|
|
)
|
|
|
|
// Inf returns positive infinity if sign >= 0, negative infinity if sign < 0.
|
|
func Inf(sign int) float64 {
|
|
var v uint64
|
|
if sign >= 0 {
|
|
v = uvinf
|
|
} else {
|
|
v = uvneginf
|
|
}
|
|
return Float64frombits(v)
|
|
}
|
|
|
|
// NaN returns an IEEE 754 ``not-a-number'' value.
|
|
func NaN() float64 { return Float64frombits(uvnan) }
|
|
|
|
// IsNaN returns whether f is an IEEE 754 ``not-a-number'' value.
|
|
func IsNaN(f float64) (is bool) {
|
|
// IEEE 754 says that only NaNs satisfy f != f.
|
|
// To avoid the floating-point hardware, could use:
|
|
// x := Float64bits(f);
|
|
// return uint32(x>>shift)&mask == mask && x != uvinf && x != uvneginf
|
|
return f != f
|
|
}
|
|
|
|
// IsInf returns whether f is an infinity, according to sign.
|
|
// If sign > 0, IsInf returns whether f is positive infinity.
|
|
// If sign < 0, IsInf returns whether f is negative infinity.
|
|
// If sign == 0, IsInf returns whether f is either infinity.
|
|
func IsInf(f float64, sign int) bool {
|
|
// Test for infinity by comparing against maximum float.
|
|
// To avoid the floating-point hardware, could use:
|
|
// x := Float64bits(f);
|
|
// return sign >= 0 && x == uvinf || sign <= 0 && x == uvneginf;
|
|
return sign >= 0 && f > MaxFloat64 || sign <= 0 && f < -MaxFloat64
|
|
}
|