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

1 files changed, 33 insertions, 0 deletions

diff --git a/libgo/go/math/ldexp.go b/libgo/go/math/ldexp.go
new file mode 100644
index 00000000000..d04bf1581ad
--- /dev/null
+++ b/libgo/go/math/ldexp.go
@@ -0,0 +1,33 @@
+// 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
+
+// Ldexp is the inverse of Frexp.
+// It returns frac × 2**exp.
+func Ldexp(frac float64, exp int) float64 {
+	// TODO(rsc): Remove manual inlining of IsNaN, IsInf
+	// when compiler does it for us
+	// special cases
+	switch {
+	case frac == 0:
+		return frac // correctly return -0
+	case frac != frac: // IsNaN(frac):
+		return NaN()
+	}
+	x := Float64bits(frac)
+	exp += int(x>>shift) & mask
+	if exp <= 0 {
+		return 0 // underflow
+	}
+	if exp >= mask { // overflow
+		if frac < 0 {
+			return Inf(-1)
+		}
+		return Inf(1)
+	}
+	x &^= mask << shift
+	x |= uint64(exp) << shift
+	return Float64frombits(x)
+}