test_ds_prism fails on s390x

[drew-parsons]

test_ds_prism [float64] is failing on s390x,
test log at https://ci.debian.net/packages/f/fenics-ffcx/testing/s390x/67306878/

142s =================================== FAILURES ===================================
142s ____________________________ test_ds_prism[float64] ____________________________
142s 
142s compile_args = ['-O1', '-Wall', '-Werror'], dtype = 'float64'
142s 
142s     @pytest.mark.parametrize("dtype", ["float64"])
142s     def test_ds_prism(compile_args, dtype):
142s         element = basix.ufl.element("Lagrange", "prism", 1)
142s         domain = ufl.Mesh(basix.ufl.element("Lagrange", "prism", 1, shape=(3,)))
142s         space = ufl.FunctionSpace(domain, element)
142s         u, v = ufl.TrialFunction(space), ufl.TestFunction(space)
142s     
142s         a = ufl.inner(u, v) * ufl.ds
142s         forms = [a]
142s         compiled_forms, module, _code = ffcx.codegeneration.jit.compile_forms(
142s             forms, options={"scalar_type": dtype}, cffi_extra_compile_args=compile_args
142s         )
142s     
142s         for f, compiled_f in zip(forms, compiled_forms):
142s             assert compiled_f.rank == len(f.arguments())
142s     
142s         ffi = module.ffi
142s         form0 = compiled_forms[0]
142s     
142s         offsets = form0.form_integral_offsets
142s         cell = module.lib.cell
142s         exterior_facet = module.lib.exterior_facet
142s         interior_facet = module.lib.interior_facet
142s         assert offsets[cell + 1] - offsets[cell] == 0
142s         assert offsets[exterior_facet + 1] - offsets[exterior_facet] == 2
142s         assert offsets[interior_facet + 1] - offsets[interior_facet] == 0
142s     
142s         integral_id0 = form0.form_integral_ids[offsets[exterior_facet]]
142s         integral_id1 = form0.form_integral_ids[offsets[exterior_facet] + 1]
142s         assert integral_id0 == integral_id1 == -1
142s     
142s         integral0 = form0.form_integrals[offsets[exterior_facet]]
142s         integral1 = form0.form_integrals[offsets[exterior_facet] + 1]
142s     
142s         if basix.CellType(integral0.domain) == basix.CellType.triangle:
142s             assert basix.CellType(integral1.domain) == basix.CellType.quadrilateral
142s             integral_tri = integral0
142s             integral_quad = integral1
142s         else:
142s             assert basix.CellType(integral0.domain) == basix.CellType.quadrilateral
142s             assert basix.CellType(integral1.domain) == basix.CellType.triangle
142s             integral_tri = integral1
142s             integral_quad = integral0
142s     
142s         w = np.array([], dtype=dtype)
142s         c = np.array([], dtype=dtype)
142s         entity_perm = np.array([0], dtype=np.uint8)
142s     
142s         # Test integral over triangle (facet 0)
142s         A = np.zeros((6, 6), dtype=dtype)
142s         entity_index = np.array([0], dtype=int)
142s     
142s         xdtype = dtype_to_scalar_dtype(dtype)
142s         coords = np.array(
142s             [
142s                 [0.0, 0.0, 0.0],
142s                 [1.0, 0.0, 0.0],
142s                 [0.0, 1.0, 0.0],
142s                 [0.0, 0.0, 1.0],
142s                 [1.0, 0.0, 1.0],
142s                 [0.0, 1.0, 1.0],
142s             ],
142s             dtype=xdtype,
142s         )
142s     
142s         c_type, c_xtype = dtype_to_c_type(dtype), dtype_to_c_type(xdtype)
142s     
142s         kernel = getattr(integral_tri, f"tabulate_tensor_{dtype}")
142s     
142s         kernel(
142s             ffi.cast(f"{c_type} *", A.ctypes.data),
142s             ffi.cast(f"{c_type} *", w.ctypes.data),
142s             ffi.cast(f"{c_type} *", c.ctypes.data),
142s             ffi.cast(f"{c_xtype} *", coords.ctypes.data),
142s             ffi.cast("int *", entity_index.ctypes.data),
142s             ffi.cast("uint8_t *", entity_perm.ctypes.data),
142s             ffi.NULL,
142s         )
142s     
142s         assert np.allclose(
142s             A,
142s             np.array(
142s                 [
142s                     [1 / 12, 1 / 24, 1 / 24, 0, 0, 0],
142s                     [1 / 24, 1 / 12, 1 / 24, 0, 0, 0],
142s                     [1 / 24, 1 / 24, 1 / 12, 0, 0, 0],
142s                     [0, 0, 0, 0, 0, 0],
142s                     [0, 0, 0, 0, 0, 0],
142s                     [0, 0, 0, 0, 0, 0],
142s                 ]
142s             ),
142s         )
142s     
142s         # Test integral over quadrilateral (facet 1)
142s         A = np.zeros((6, 6), dtype=dtype)
142s         entity_index = np.array([1], dtype=np.int64)
142s     
142s         xdtype = dtype_to_scalar_dtype(dtype)
142s         coords = np.array(
142s             [
142s                 [0.0, 0.0, 0.0],
142s                 [1.0, 0.0, 0.0],
142s                 [0.0, 1.0, 0.0],
142s                 [0.0, 0.0, 1.0],
142s                 [1.0, 0.0, 1.0],
142s                 [0.0, 1.0, 1.0],
142s             ],
142s             dtype=xdtype,
142s         )
142s     
142s         c_type, c_xtype = dtype_to_c_type(dtype), dtype_to_c_type(xdtype)
142s     
142s         kernel = getattr(integral_quad, f"tabulate_tensor_{dtype}")
142s     
142s         kernel(
142s             ffi.cast(f"{c_type} *", A.ctypes.data),
142s             ffi.cast(f"{c_type} *", w.ctypes.data),
142s             ffi.cast(f"{c_type} *", c.ctypes.data),
142s             ffi.cast(f"{c_xtype} *", coords.ctypes.data),
142s             ffi.cast("int *", entity_index.ctypes.data),
142s             ffi.cast("uint8_t *", entity_perm.ctypes.data),
142s             ffi.NULL,
142s         )
142s     
142s >       assert np.allclose(
142s             A,
142s             np.array(
142s                 [
142s                     [1 / 9, 1 / 18, 0, 1 / 18, 1 / 36, 0],
142s                     [1 / 18, 1 / 9, 0, 1 / 36, 1 / 18, 0],
142s                     [0, 0, 0, 0, 0, 0],
142s                     [1 / 18, 1 / 36, 0, 1 / 9, 1 / 18, 0],
142s                     [1 / 36, 1 / 18, 0, 1 / 18, 1 / 9, 0],
142s                     [0, 0, 0, 0, 0, 0],
142s                 ]
142s             ),
142s         )
142s E       assert False
142s E        +  where False = <function allclose at 0x3ff8002f8f0>(array([[ 0.16666667, -0.08333333, -0.08333333,  0.        ,  0.        ,\n         0.        ],\n       [-0.08333333,  0.33333333,  0.25      ,  0.        ,  0.        ,\n         0.        ],\n       [-0.08333333,  0.25      ,  0.33333333,  0.        ,  0.        ,\n         0.        ],\n       [ 0.        ,  0.        ,  0.        ,  0.        ,  0.        ,\n         0.        ],\n       [ 0.        ,  0.        ,  0.        ,  0.        ,  0.        ,\n         0.        ],\n       [ 0.        ,  0.        ,  0.        ,  0.        ,  0.        ,\n         0.        ]]), array([[0.11111111, 0.05555556, 0.        , 0.05555556, 0.02777778,\n        0.        ],\n       [0.05555556, 0.11111111, 0.        , 0.02777778, 0.05555556,\n        0.        ],\n       [0.        , 0.        , 0.        , 0.        , 0.        ,\n        0.        ],\n       [0.05555556, 0.02777778, 0.        , 0.11111111, 0.05555556,\n        0.        ],\n       [0.02777778, 0.05555556, 0.        , 0.05555556, 0.11111111,\n        0.        ],\n       [0.        , 0.        , 0.        , 0.        , 0.        ,\n        0.        ]]))
142s E        +    where <function allclose at 0x3ff8002f8f0> = np.allclose
142s E        +    and   array([[0.11111111, 0.05555556, 0.        , 0.05555556, 0.02777778,\n        0.        ],\n       [0.05555556, 0.11111111, 0.        , 0.02777778, 0.05555556,\n        0.        ],\n       [0.        , 0.        , 0.        , 0.        , 0.        ,\n        0.        ],\n       [0.05555556, 0.02777778, 0.        , 0.11111111, 0.05555556,\n        0.        ],\n       [0.02777778, 0.05555556, 0.        , 0.05555556, 0.11111111,\n        0.        ],\n       [0.        , 0.        , 0.        , 0.        , 0.        ,\n        0.        ]]) = <built-in function array>([[0.1111111111111111, 0.05555555555555555, 0, 0.05555555555555555, 0.027777777777777776, 0], [0.05555555555555555, 0.1111111111111111, 0, 0.027777777777777776, 0.05555555555555555, 0], [0, 0, 0, 0, 0, 0], [0.05555555555555555, 0.027777777777777776, 0, 0.1111111111111111, 0.05555555555555555, 0], [0.027777777777777776, 0.05555555555555555, 0, 0.05555555555555555, 0.1111111111111111, 0], [0, 0, 0, 0, 0, 0]])
142s E        +      where <built-in function array> = np.array
142s 
142s /tmp/autopkgtest-lxc.nynvsvx6/downtmp/build.Ir2/src/test/test_jit_forms.py:1417: AssertionError
142s =========================== short test summary info ============================
142s SKIPPED [4] test/test_signatures.py:67: Numba not installed
142s FAILED test/test_jit_forms.py::test_ds_prism[float64] - assert False
142s ============= 1 failed, 197 passed, 4 skipped in 64.56s (0:01:04) ==============

I'll skip the test in the debian build in the meantime.

[schnellerhase]

s390x is a big-endian platform - could be caused by explicit bit layout assumptions in the orientation computation logic. Hard to replicate, is there a better solution than virtualisation?

[drew-parsons]

I'd expect a virtual machine ought to reproduce bigendian bit layout correctly.
But for actual hardware access, one option is to request guest access to the debian porterbox.

[schnellerhase]

Can replicate, with a virtualised CI at https://github.com/FEniCS/ffcx/tree/schnellerhase/s390x.