From 7a9389330e91acc3ed05deac2d198af25d13cf3c Mon Sep 17 00:00:00 2001
From: Ian Lance Taylor <ian@gcc.gnu.org>
Date: Fri, 3 Dec 2010 04:34:57 +0000
Subject: 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
---
 libgo/go/math/bits.go | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 libgo/go/math/bits.go

(limited to 'libgo/go/math/bits.go')

diff --git a/libgo/go/math/bits.go b/libgo/go/math/bits.go
new file mode 100644
index 0000000..d36cd18
--- /dev/null
+++ b/libgo/go/math/bits.go
@@ -0,0 +1,49 @@
+// 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
+}
-- 
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