Add 7D broadcast test with non-adjacent dimensions

Tests element space size calculation when two non-adjacent middle
dimensions (dims 2 and 4) have stride 0 (broadcast).

Author: tenpercent

test/util/unit_tensor_descriptor_helper.cpp

@@ -40,6 +40,22 @@ TEST(MakeNaiveTensorDescriptor, BroadcastDimension)
     EXPECT_EQ(desc.GetElementSpaceSize(), 5);
 }
 
+TEST(MakeNaiveTensorDescriptor, BroadcastNonAdjacentDims7D)
+{
+    // 7D tensor: 2x3x5x7x11x13x17 with broadcast on dims 2 and 4 (non-adjacent)
+    // Underlying data is 2x3x7x13x17 = 9282 elements, broadcast over dims 2 and 4
+    // strides: [4641, 1547, 0, 221, 0, 17, 1]
+    // element_space_size = 1 + (2-1)*4641 + (3-1)*1547 + (5-1)*0 + (7-1)*221
+    //                        + (11-1)*0 + (13-1)*17 + (17-1)*1
+    //                    = 1 + 4641 + 3094 + 0 + 1326 + 0 + 204 + 16 = 9282
+    constexpr auto lengths = make_tuple(Number<2>{}, Number<3>{}, Number<5>{}, Number<7>{},
+                                        Number<11>{}, Number<13>{}, Number<17>{});
+    constexpr auto strides = make_tuple(Number<4641>{}, Number<1547>{}, Number<0>{}, Number<221>{},
+                                        Number<0>{}, Number<17>{}, Number<1>{});
+    constexpr auto desc    = make_naive_tensor_descriptor(lengths, strides);
+    EXPECT_EQ(desc.GetElementSpaceSize(), 9282);
+}
+
 TEST(MakeNaiveTensorDescriptor, WithPaddingArbitrary)
 {
     // 11x7x3 tensor with arbitrary strides [2, 97, 23] (prime numbers, no common factors)