obtained gcc-4.6.4.tar.bz2 from upstream website;upstream

verified gcc-4.6.4.tar.bz2.sig;
imported gcc-4.6.4 source tree from verified upstream tarball.

downloading a git-generated archive based on the 'upstream' tag
should provide you with a source tree that is binary identical
to the one extracted from the above tarball.

if you have obtained the source via the command 'git clone',
however, do note that line-endings of files in your working
directory might differ from line-endings of the respective
files in the upstream repository.

1 files changed, 63 insertions, 0 deletions

diff --git a/libgo/go/math/hypot_port.go b/libgo/go/math/hypot_port.go
new file mode 100644
index 000000000..27f335ba2
--- /dev/null
+++ b/libgo/go/math/hypot_port.go
@@ -0,0 +1,63 @@
+// Copyright 2009-2010 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
+
+/*
+	Hypot -- sqrt(p*p + q*q), but overflows only if the result does.
+	See:
+		Cleve Moler and Donald Morrison,
+		Replacing Square Roots by Pythagorean Sums
+		IBM Journal of Research and Development,
+		Vol. 27, Number 6, pp. 577-581, Nov. 1983
+*/
+
+// Hypot computes Sqrt(p*p + q*q), taking care to avoid
+// unnecessary overflow and underflow.
+//
+// Special cases are:
+//	Hypot(p, q) = +Inf if p or q is infinite
+//	Hypot(p, q) = NaN if p or q is NaN
+func hypotGo(p, q float64) float64 {
+	// TODO(rsc): Remove manual inlining of IsNaN, IsInf
+	// when compiler does it for us
+	// special cases
+	switch {
+	case p < -MaxFloat64 || p > MaxFloat64 || q < -MaxFloat64 || q > MaxFloat64: // IsInf(p, 0) || IsInf(q, 0):
+		return Inf(1)
+	case p != p || q != q: // IsNaN(p) || IsNaN(q):
+		return NaN()
+	}
+	if p < 0 {
+		p = -p
+	}
+	if q < 0 {
+		q = -q
+	}
+
+	if p < q {
+		p, q = q, p
+	}
+
+	if p == 0 {
+		return 0
+	}
+
+	pfac := p
+	q = q / p
+	r := q
+	p = 1
+	for {
+		r = r * r
+		s := r + 4
+		if s == 4 {
+			return p * pfac
+		}
+		r = r / s
+		p = p + 2*r*p
+		q = q * r
+		r = q / p
+	}
+	panic("unreachable")
+}