blas/gonum: add test for Zgeru
diff --git a/blas/gonum/level2cmplx128_test.go b/blas/gonum/level2cmplx128_test.go
index db784d4..ecb2198 100644
--- a/blas/gonum/level2cmplx128_test.go
+++ b/blas/gonum/level2cmplx128_test.go
@@ -13,3 +13,7 @@
 func TestZgerc(t *testing.T) {
 	testblas.ZgercTest(t, impl)
 }
+
+func TestZgeru(t *testing.T) {
+	testblas.ZgeruTest(t, impl)
+}
diff --git a/blas/testblas/zgeru.go b/blas/testblas/zgeru.go
new file mode 100644
index 0000000..09c66e7
--- /dev/null
+++ b/blas/testblas/zgeru.go
@@ -0,0 +1,257 @@
+// Copyright ©2017 The gonum 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 testblas
+
+import (
+	"testing"
+)
+
+type Zgeruer interface {
+	Zgeru(m, n int, alpha complex128, x []complex128, incX int, y []complex128, incY int, a []complex128, lda int)
+}
+
+func ZgeruTest(t *testing.T, impl Zgeruer) {
+	for tc, test := range []struct {
+		alpha complex128
+		x     []complex128
+		incX  int
+		y     []complex128
+		incY  int
+		a     []complex128
+
+		want []complex128
+	}{
+		{
+			incX:  1,
+			incY:  1,
+			alpha: 1 + 2i,
+		},
+		{
+			incX:  1,
+			incY:  1,
+			alpha: 1 + 2i,
+			x:     []complex128{1 + 13i, 18 + 15i, 10 + 18i},
+			y:     []complex128{15 + 12i, 4 + 8i, 5 + 16i, 19 + 12i},
+			a: []complex128{
+				4 + 7i, 4 + 7i, 12 + 3i, 9 + 10i,
+				3 + 3i, 1 + 2i, 17 + 17i, 9 + 18i,
+				14 + 12i, 9 + 16i, 1 + 1i, 9 + 1i,
+			},
+			want: []complex128{
+				-551 - 68i, -216 - 133i, -353 - 322i, -646 - 5i,
+				-789 + 624i, -455 + 110i, -859 + 80i, -831 + 843i,
+				-832 + 270i, -399 - 40i, -737 - 225i, -941 + 411i,
+			},
+		},
+		{
+			incX:  7,
+			incY:  13,
+			alpha: 1 + 2i,
+			x:     []complex128{1 + 13i, 18 + 15i, 10 + 18i},
+			y:     []complex128{15 + 12i, 4 + 8i, 5 + 16i, 19 + 12i},
+			a: []complex128{
+				4 + 7i, 4 + 7i, 12 + 3i, 9 + 10i,
+				3 + 3i, 1 + 2i, 17 + 17i, 9 + 18i,
+				14 + 12i, 9 + 16i, 1 + 1i, 9 + 1i,
+			},
+			want: []complex128{
+				-551 - 68i, -216 - 133i, -353 - 322i, -646 - 5i,
+				-789 + 624i, -455 + 110i, -859 + 80i, -831 + 843i,
+				-832 + 270i, -399 - 40i, -737 - 225i, -941 + 411i,
+			},
+		},
+		{
+			incX:  1,
+			incY:  13,
+			alpha: 1 + 2i,
+			x:     []complex128{1 + 13i, 18 + 15i, 10 + 18i},
+			y:     []complex128{15 + 12i, 4 + 8i, 5 + 16i, 19 + 12i},
+			a: []complex128{
+				4 + 7i, 4 + 7i, 12 + 3i, 9 + 10i,
+				3 + 3i, 1 + 2i, 17 + 17i, 9 + 18i,
+				14 + 12i, 9 + 16i, 1 + 1i, 9 + 1i,
+			},
+			want: []complex128{
+				-551 - 68i, -216 - 133i, -353 - 322i, -646 - 5i,
+				-789 + 624i, -455 + 110i, -859 + 80i, -831 + 843i,
+				-832 + 270i, -399 - 40i, -737 - 225i, -941 + 411i,
+			},
+		},
+		{
+			incX:  1,
+			incY:  -13,
+			alpha: 1 + 2i,
+			x:     []complex128{1 + 13i, 18 + 15i, 10 + 18i},
+			y:     []complex128{19 + 12i, 5 + 16i, 4 + 8i, 15 + 12i},
+			a: []complex128{
+				4 + 7i, 4 + 7i, 12 + 3i, 9 + 10i,
+				3 + 3i, 1 + 2i, 17 + 17i, 9 + 18i,
+				14 + 12i, 9 + 16i, 1 + 1i, 9 + 1i,
+			},
+			want: []complex128{
+				-551 - 68i, -216 - 133i, -353 - 322i, -646 - 5i,
+				-789 + 624i, -455 + 110i, -859 + 80i, -831 + 843i,
+				-832 + 270i, -399 - 40i, -737 - 225i, -941 + 411i,
+			},
+		},
+		{
+			incX:  7,
+			incY:  1,
+			alpha: 1 + 2i,
+			x:     []complex128{1 + 13i, 18 + 15i, 10 + 18i},
+			y:     []complex128{15 + 12i, 4 + 8i, 5 + 16i, 19 + 12i},
+			a: []complex128{
+				4 + 7i, 4 + 7i, 12 + 3i, 9 + 10i,
+				3 + 3i, 1 + 2i, 17 + 17i, 9 + 18i,
+				14 + 12i, 9 + 16i, 1 + 1i, 9 + 1i,
+			},
+			want: []complex128{
+				-551 - 68i, -216 - 133i, -353 - 322i, -646 - 5i,
+				-789 + 624i, -455 + 110i, -859 + 80i, -831 + 843i,
+				-832 + 270i, -399 - 40i, -737 - 225i, -941 + 411i,
+			},
+		},
+		{
+			incX:  -7,
+			incY:  1,
+			alpha: 1 + 2i,
+			x:     []complex128{10 + 18i, 18 + 15i, 1 + 13i},
+			y:     []complex128{15 + 12i, 4 + 8i, 5 + 16i, 19 + 12i},
+			a: []complex128{
+				4 + 7i, 4 + 7i, 12 + 3i, 9 + 10i,
+				3 + 3i, 1 + 2i, 17 + 17i, 9 + 18i,
+				14 + 12i, 9 + 16i, 1 + 1i, 9 + 1i,
+			},
+			want: []complex128{
+				-551 - 68i, -216 - 133i, -353 - 322i, -646 - 5i,
+				-789 + 624i, -455 + 110i, -859 + 80i, -831 + 843i,
+				-832 + 270i, -399 - 40i, -737 - 225i, -941 + 411i,
+			},
+		},
+		{
+			incX:  -7,
+			incY:  -13,
+			alpha: 1 + 2i,
+			x:     []complex128{10 + 18i, 18 + 15i, 1 + 13i},
+			y:     []complex128{19 + 12i, 5 + 16i, 4 + 8i, 15 + 12i},
+			a: []complex128{
+				4 + 7i, 4 + 7i, 12 + 3i, 9 + 10i,
+				3 + 3i, 1 + 2i, 17 + 17i, 9 + 18i,
+				14 + 12i, 9 + 16i, 1 + 1i, 9 + 1i,
+			},
+			want: []complex128{
+				-551 - 68i, -216 - 133i, -353 - 322i, -646 - 5i,
+				-789 + 624i, -455 + 110i, -859 + 80i, -831 + 843i,
+				-832 + 270i, -399 - 40i, -737 - 225i, -941 + 411i,
+			},
+		},
+		{
+			incX:  1,
+			incY:  1,
+			alpha: 1 + 2i,
+			x:     []complex128{5 + 16i, 12 + 19i, 9 + 7i, 2 + 4i},
+			y:     []complex128{18 + 7i, 20 + 15i, 12 + 14i},
+			a: []complex128{
+				8 + 17i, 2 + 2i, 8 + 17i,
+				1 + 10i, 10 + 15i, 4 + 18i,
+				11 + 3i, 15 + 7i, 12 + 15i,
+				20 + 10i, 8 + 13i, 19 + 10i,
+			},
+			want: []complex128{
+				-660 + 296i, -928 + 117i, -680 - 49i,
+				-768 + 602i, -1155 + 485i, -910 + 170i,
+				-254 + 418i, -460 + 432i, -398 + 245i,
+				-144 + 112i, -232 + 83i, -165 + 22i,
+			},
+		},
+		{
+			incX:  7,
+			incY:  13,
+			alpha: 1 + 2i,
+			x:     []complex128{5 + 16i, 12 + 19i, 9 + 7i, 2 + 4i},
+			y:     []complex128{18 + 7i, 20 + 15i, 12 + 14i},
+			a: []complex128{
+				8 + 17i, 2 + 2i, 8 + 17i,
+				1 + 10i, 10 + 15i, 4 + 18i,
+				11 + 3i, 15 + 7i, 12 + 15i,
+				20 + 10i, 8 + 13i, 19 + 10i,
+			},
+			want: []complex128{
+				-660 + 296i, -928 + 117i, -680 - 49i,
+				-768 + 602i, -1155 + 485i, -910 + 170i,
+				-254 + 418i, -460 + 432i, -398 + 245i,
+				-144 + 112i, -232 + 83i, -165 + 22i,
+			},
+		},
+		{
+			incX:  -7,
+			incY:  -13,
+			alpha: 1 + 2i,
+			x:     []complex128{2 + 4i, 9 + 7i, 12 + 19i, 5 + 16i},
+			y:     []complex128{12 + 14i, 20 + 15i, 18 + 7i},
+			a: []complex128{
+				8 + 17i, 2 + 2i, 8 + 17i,
+				1 + 10i, 10 + 15i, 4 + 18i,
+				11 + 3i, 15 + 7i, 12 + 15i,
+				20 + 10i, 8 + 13i, 19 + 10i,
+			},
+			want: []complex128{
+				-660 + 296i, -928 + 117i, -680 - 49i,
+				-768 + 602i, -1155 + 485i, -910 + 170i,
+				-254 + 418i, -460 + 432i, -398 + 245i,
+				-144 + 112i, -232 + 83i, -165 + 22i,
+			},
+		},
+		{
+			incX:  -7,
+			incY:  -13,
+			alpha: 0,
+			x:     []complex128{5 + 16i, 12 + 19i, 9 + 7i, 2 + 4i},
+			y:     []complex128{18 + 7i, 20 + 15i, 12 + 14i},
+			a: []complex128{
+				8 + 17i, 2 + 2i, 8 + 17i,
+				1 + 10i, 10 + 15i, 4 + 18i,
+				11 + 3i, 15 + 7i, 12 + 15i,
+				20 + 10i, 8 + 13i, 19 + 10i,
+			},
+			want: []complex128{
+				8 + 17i, 2 + 2i, 8 + 17i,
+				1 + 10i, 10 + 15i, 4 + 18i,
+				11 + 3i, 15 + 7i, 12 + 15i,
+				20 + 10i, 8 + 13i, 19 + 10i,
+			},
+		},
+	} {
+		m := len(test.x)
+		n := len(test.y)
+		incX := test.incX
+		incY := test.incY
+
+		for _, lda := range []int{max(1, n), n + 20} {
+			x := makeZVector(test.x, incX)
+			xCopy := make([]complex128, len(x))
+			copy(xCopy, x)
+
+			y := makeZVector(test.y, incY)
+			yCopy := make([]complex128, len(y))
+			copy(yCopy, y)
+
+			a := makeZGeneral(test.a, m, n, lda)
+			want := makeZGeneral(test.want, m, n, lda)
+
+			impl.Zgeru(m, n, test.alpha, x, incX, y, incY, a, lda)
+
+			if !zsame(x, xCopy) {
+				t.Errorf("Case %v: unexpected modification of x", tc)
+			}
+			if !zsame(y, yCopy) {
+				t.Errorf("Case %v: unexpected modification of y", tc)
+			}
+			if !zsame(want, a) {
+				t.Errorf("Case %v: unexpected result\nwant %v\ngot %v", tc, want, a)
+			}
+		}
+	}
+}