[FRONTEND] Raise broadcast error (#555)

python/test/unit/language/test_core.py

@@ -385,6 +385,8 @@ def test_index1d(expr, dtype_str, device='cuda'):
     rank_y = expr.count(',') + 1
     shape_x = [32 for _ in range(rank_x)]
     shape_z = [32 for _ in range(rank_y)]
+    shape_z_rank_mismatch = [32 for _ in range(rank_y + 1)]
+    shape_z_dim_mismatch = [64 for _ in range(rank_y)]
 
     # Triton kernel
     @triton.jit
@@ -395,12 +397,17 @@ def test_index1d(expr, dtype_str, device='cuda'):
         z = GENERATE_TEST_HERE
         tl.store(Z_PTR_EXPR, z)
 
-    to_replace = {
-        'X_PTR_EXPR': make_ptr_str('X', shape_x),
-        'Z_PTR_EXPR': make_ptr_str('Z', shape_z),
-        'GENERATE_TEST_HERE': expr,
-    }
-    kernel = patch_kernel(kernel, to_replace)
+    def generate_kernel(shape_x, shape_z):
+        to_replace = {
+            'X_PTR_EXPR': make_ptr_str('X', shape_x),
+            'Z_PTR_EXPR': make_ptr_str('Z', shape_z),
+            'GENERATE_TEST_HERE': expr,
+        }
+        return patch_kernel(kernel, to_replace)
+
+    kernel_match = generate_kernel(shape_x, shape_z)
+    kernel_dim_mismatch = generate_kernel(shape_x, shape_z_dim_mismatch)
+    kernel_rank_mismatch = generate_kernel(shape_x, shape_z_rank_mismatch)
 
     # torch result
     x = numpy_random(shape_x, dtype_str=dtype_str)
@@ -409,10 +416,21 @@ def test_index1d(expr, dtype_str, device='cuda'):
     # triton result
     z_tri = to_triton(np.empty_like(z_ref), device=device)
     x_tri = to_triton(x)
-    kernel[(1, )](z_tri, x_tri, num_warps=1, SIZE=shape_x[0])
+    kernel_match[(1, )](z_tri, x_tri, num_warps=1, SIZE=shape_x[0])
     # compare
     assert (z_ref == to_numpy(z_tri)).all()
 
+    def catch_compilation_error(kernel):
+        try:
+            kernel[(1, )](z_tri, x_tri, num_warps=1, SIZE=shape_x[0])
+        except triton.code_gen.CompilationError as e:
+            np.testing.assert_(True)
+        except BaseException:
+            np.testing.assert_(False)
+
+    catch_compilation_error(kernel_dim_mismatch)
+    catch_compilation_error(kernel_rank_mismatch)
+
 
 # ---------------
 # test tuples

python/triton/language/semantic.py

@@ -482,6 +482,11 @@ def broadcast_impl_shape(input: tl.tensor,
         raise ValueError(f"Cannot broadcast, rank mismatch: {src_shape}, {shape}")
     if shape == src_shape:
         return input
+    for i in range(len(src_shape)):
+        if shape[i] != src_shape[i] and src_shape[i] != 1:
+            raise ValueError(f"Cannot broadcast, the expanded size of the tensor ({shape[i]})"
+                             f" must match the existing size ({src_shape[1]}) at non-singleton dimension"
+                             f" {i}: {src_shape}, {shape}")
     ret_ty = tl.block_type(input.type.scalar, shape)
     return tl.tensor(builder.create_broadcast(input.handle, shape), ret_ty)