libgo: Update to revision 15193:6fdc1974457c of master library.

From-SVN: r194692

5 files changed, 60 insertions, 2 deletions

diff --git a/libgo/go/math/all_test.go b/libgo/go/math/all_test.go
index cdea8035f9a..0d8b10f67fa 100644
--- a/libgo/go/math/all_test.go
+++ b/libgo/go/math/all_test.go
@@ -2281,6 +2281,13 @@ func TestLog2(t *testing.T) {
 			t.Errorf("Log2(%g) = %g, want %g", vflogSC[i], f, logSC[i])
 		}
 	}
+	for i := -1074; i <= 1023; i++ {
+		f := Ldexp(1, i)
+		l := Log2(f)
+		if l != float64(i) {
+			t.Errorf("Log2(2**%d) = %g, want %d", i, l, i)
+		}
+	}
 }
 
 func TestModf(t *testing.T) {
diff --git a/libgo/go/math/big/int.go b/libgo/go/math/big/int.go
index 95c0d58ee97..63a4536e2a0 100644
--- a/libgo/go/math/big/int.go
+++ b/libgo/go/math/big/int.go
@@ -51,6 +51,13 @@ func (z *Int) SetInt64(x int64) *Int {
 	return z
 }
 
+// SetUint64 sets z to x and returns z.
+func (z *Int) SetUint64(x uint64) *Int {
+	z.abs = z.abs.setUint64(uint64(x))
+	z.neg = false
+	return z
+}
+
 // NewInt allocates and returns a new Int set to x.
 func NewInt(x int64) *Int {
 	return new(Int).SetInt64(x)
@@ -519,6 +526,19 @@ func (x *Int) Int64() int64 {
 	return v
 }
 
+// Uint64 returns the int64 representation of x.
+// If x cannot be represented in an uint64, the result is undefined.
+func (x *Int) Uint64() uint64 {
+	if len(x.abs) == 0 {
+		return 0
+	}
+	v := uint64(x.abs[0])
+	if _W == 32 && len(x.abs) > 1 {
+		v |= uint64(x.abs[1]) << 32
+	}
+	return v
+}
+
 // SetString sets z to the value of s, interpreted in the given base,
 // and returns z and a boolean indicating success. If SetString fails,
 // the value of z is undefined but the returned value is nil.
diff --git a/libgo/go/math/big/int_test.go b/libgo/go/math/big/int_test.go
index d3c5a0e8bfe..fd6d152b39d 100644
--- a/libgo/go/math/big/int_test.go
+++ b/libgo/go/math/big/int_test.go
@@ -1135,6 +1135,36 @@ func TestInt64(t *testing.T) {
 	}
 }
 
+var uint64Tests = []uint64{
+	0,
+	1,
+	4294967295,
+	4294967296,
+	8589934591,
+	8589934592,
+	9223372036854775807,
+	9223372036854775808,
+	18446744073709551615, // 1<<64 - 1
+}
+
+func TestUint64(t *testing.T) {
+	in := new(Int)
+	for i, testVal := range uint64Tests {
+		in.SetUint64(testVal)
+		out := in.Uint64()
+
+		if out != testVal {
+			t.Errorf("#%d got %d want %d", i, out, testVal)
+		}
+
+		str := fmt.Sprint(testVal)
+		strOut := in.String()
+		if strOut != str {
+			t.Errorf("#%d.String got %s want %s", i, strOut, str)
+		}
+	}
+}
+
 var bitwiseTests = []struct {
 	x, y                 string
 	and, or, xor, andNot string
diff --git a/libgo/go/math/big/nat.go b/libgo/go/math/big/nat.go
index 13a623a7032..9d09f97b77b 100644
--- a/libgo/go/math/big/nat.go
+++ b/libgo/go/math/big/nat.go
@@ -826,7 +826,7 @@ func (x nat) string(charset string) string {
 
 // Convert words of q to base b digits in s. If q is large, it is recursively "split in half"
 // by nat/nat division using tabulated divisors. Otherwise, it is converted iteratively using
-// repeated nat/Word divison.
+// repeated nat/Word division.
 //
 // The iterative method processes n Words by n divW() calls, each of which visits every Word in the
 // incrementally shortened q for a total of n + (n-1) + (n-2) ... + 2 + 1, or n(n+1)/2 divW()'s.
diff --git a/libgo/go/math/log10.go b/libgo/go/math/log10.go
index 3d2cec6656c..d880ec2040d 100644
--- a/libgo/go/math/log10.go
+++ b/libgo/go/math/log10.go
@@ -26,5 +26,6 @@ func Log2(x float64) float64 {
 }
 
 func log2(x float64) float64 {
-	return Log(x) * (1 / Ln2)
+	frac, exp := Frexp(x)
+	return Log(frac)*(1/Ln2) + float64(exp)
 }