Merge pull request #2578 from devitocodes/issue_2577

compiler: Fix issue 2577 - edit printer for unevaluation Mul

Author: mloubout

.github/workflows/pytest-core-nompi.yml

@@ -172,7 +172,7 @@ jobs:
 
     - name: Test with pytest
       run: |
-        ${{ env.RUN_CMD }} pytest -k "${{ matrix.test-set }}" -m "not parallel" --cov --cov-config=.coveragerc --cov-report=xml ${{ env.TESTS }}
+        ${{ env.RUN_CMD }} pytest -k "${{ matrix.test-set }}" -m "not parallel" --cov --cov-config=.coveragerc --cov-report=xml tests/
 
     - name: Upload coverage to Codecov
       if: "!contains(matrix.name, 'docker')"

devito/finite_differences/differentiable.py

@@ -17,7 +17,7 @@
 from devito.finite_differences.tools import make_shift_x0, coeff_priority
 from devito.logger import warning
 from devito.tools import (as_tuple, filter_ordered, flatten, frozendict,
-                          infer_dtype, is_integer, split)
+                          infer_dtype, is_integer, split, is_number)
 from devito.types import Array, DimensionTuple, Evaluable, StencilDimension
 from devito.types.basic import AbstractFunction
 
@@ -548,20 +548,19 @@ def __new__(cls, *args, **kwargs):
         nested, others = split(args, lambda e: isinstance(e, Mul))
         args = flatten(e.args for e in nested) + list(others)
 
+        # Gather all numbers and simplify
+        nums, others = split(args, lambda e: is_number(e))
+        scalar = sympy.Mul(*nums)
+
         # a*0 -> 0
-        if any(i == 0 for i in args):
+        if scalar == 0:
             return sympy.S.Zero
 
         # a*1 -> a
-        args = [i for i in args if i != 1]
-
-        # a*-1 -> a*-1
-        # a*-1*-1 -> a
-        # a*-1*-1*-1 -> a*-1
-        nminus = len([i for i in args if i == sympy.S.NegativeOne])
-        args = [i for i in args if i != sympy.S.NegativeOne]
-        if nminus % 2 == 1:
-            args.append(sympy.S.NegativeOne)
+        if scalar - 1 == 0:
+            args = others
+        else:
+            args = [scalar] + others
 
         # Reorder for homogeneity with pure SymPy types
         _mulsort(args)

devito/symbolics/extended_sympy.py

@@ -622,6 +622,10 @@ def __new__(cls, name, arguments=None, template=None, **kwargs):
 
         return obj
 
+    def _eval_is_commutative(self):
+        # DefFunction defaults to commutative
+        return True
+
     @property
     def name(self):
         return self._name

devito/tools/utils.py

@@ -12,7 +12,7 @@
            'roundm', 'powerset', 'invert', 'flatten', 'single_or', 'filter_ordered',
            'as_mapper', 'filter_sorted', 'pprint', 'sweep', 'all_equal', 'as_list',
            'indices_to_slices', 'indices_to_sections', 'transitive_closure',
-           'humanbytes', 'contains_val', 'sorted_priority', 'as_set']
+           'humanbytes', 'contains_val', 'sorted_priority', 'as_set', 'is_number']
 
 
 def prod(iterable, initial=1):
@@ -82,6 +82,13 @@ def is_integer(value):
     return isinstance(value, (int, np.integer, sympy.Integer))
 
 
+def is_number(value):
+    """
+    A thorough instance comparison for all number types.
+    """
+    return isinstance(value, (int, float, np.number, sympy.Number))
+
+
 def contains_val(val, items):
     try:
         return val in items

examples/seismic/tutorials/05_staggered_acoustic.ipynb

@@ -130,7 +130,7 @@
        "$\\displaystyle \\left[\\begin{matrix}v_x(t + dt, x + h_x/2, z)\\\\v_z(t + dt, x, z + h_z/2)\\end{matrix}\\right] = \\left[\\begin{matrix}dt \\left(1.0 \\frac{\\partial}{\\partial x} p(t, x, z) + \\frac{v_x(t, x + h_x/2, z)}{dt}\\right)\\\\dt \\left(1.0 \\frac{\\partial}{\\partial z} p(t, x, z) + \\frac{v_z(t, x, z + h_z/2)}{dt}\\right)\\end{matrix}\\right]$"
       ],
       "text/plain": [
-       "Eq(Vector(v_x(t + dt, x + h_x/2, z), v_z(t + dt, x, z + h_z/2)), Vector(dt*(1.0*Derivative(p(t, x, z), x) + v_x(t, x + h_x/2, z)/dt), dt*(1.0*Derivative(p(t, x, z), z) + v_z(t, x, z + h_z/2)/dt)))"
+       "Eq(Vector(v_x(t + dt, x + h_x/2, z), v_z(t + dt, x, z + h_z/2)), Vector(dt*(Derivative(p(t, x, z), x) + v_x(t, x + h_x/2, z)/dt), dt*(Derivative(p(t, x, z), z) + v_z(t, x, z + h_z/2)/dt)))"
       ]
      },
      "execution_count": 7,

tests/test_dse.py

@@ -88,7 +88,7 @@ def test_pow_to_mul(expr, expected):
 
 
 @pytest.mark.parametrize('expr,expected', [
-    ('s - SizeOf("int")*fa[x]', 's - fa[x]*sizeof(int)'),
+    ('s - SizeOf("int")*fa[x]', 's - sizeof(int)*fa[x]'),
     ('foo(4*fa[x] + 4*fb[x])', 'foo(4*(fa[x] + fb[x]))'),
     ('floor(0.1*a + 0.1*fa[x])', 'floor(0.1*(a + fa[x]))'),
     ('floor(0.1*(a + fa[x]))', 'floor(0.1*(a + fa[x]))'),

tests/test_symbolic_coefficients.py

@@ -202,8 +202,8 @@ def test_staggered_equation(self):
 
         eq_f = Eq(f, f.dx2(weights=weights))
 
-        expected = 'Eq(f(x + h_x/2), 1.0*f(x - h_x/2)/h_x**2 - 2.0*f(x + h_x/2)/h_x**2 '\
-            '+ 1.0*f(x + 3*h_x/2)/h_x**2)'
+        expected = 'Eq(f(x + h_x/2), f(x - h_x/2)/h_x**2 - 2.0*f(x + h_x/2)/h_x**2 '\
+            '+ f(x + 3*h_x/2)/h_x**2)'
         assert(str(eq_f.evaluate) == expected)
 
     @pytest.mark.parametrize('stagger', [True, False])

tests/test_symbolics.py

@@ -7,14 +7,14 @@
 from sympy import Expr, Number, Symbol
 from devito import (Constant, Dimension, Grid, Function, solve, TimeFunction, Eq,  # noqa
                     Operator, SubDimension, norm, Le, Ge, Gt, Lt, Abs, sin, cos,
-                    Min, Max)
-from devito.finite_differences.differentiable import SafeInv, Weights
+                    Min, Max, SubDomain)
+from devito.finite_differences.differentiable import SafeInv, Weights, Mul
 from devito.ir import Expression, FindNodes, ccode
 from devito.symbolics import (retrieve_functions, retrieve_indexed, evalrel,  # noqa
                               CallFromPointer, Cast, DefFunction, FieldFromPointer,
                               INT, FieldFromComposite, IntDiv, Namespace, Rvalue,
                               ReservedWord, ListInitializer, uxreplace, pow_to_mul,
-                              retrieve_derivatives, BaseCast)
+                              retrieve_derivatives, BaseCast, SizeOf)
 from devito.tools import as_tuple
 from devito.types import (Array, Bundle, FIndexed, LocalObject, Object,
                           ComponentAccess, StencilDimension, Symbol as dSymbol)
@@ -874,3 +874,41 @@ def test_assumptions(self, op, expr, assumptions, expected):
         assumptions = eval(assumptions)
         expected = eval(expected)
         assert evalrel(op, eqn, assumptions) == expected
+
+
+def test_issue_2577a():
+    u = TimeFunction(name='u', grid=Grid((2,)))
+    x = u.grid.dimensions[0]
+    expr = Mul(-1, -1., x, u)
+    assert expr.args == (x, u)
+    eq = Eq(u.forward, expr)
+    op = Operator(eq)
+
+    assert '--' not in str(op.ccode)
+
+
+def test_issue_2577b():
+    class SD0(SubDomain):
+        name = 'sd0'
+
+        def define(self, dimensions):
+            x, = dimensions
+            return {x: ('middle', 1, 1)}
+
+    grid = Grid(shape=(11,))
+
+    sd0 = SD0(grid=grid)
+
+    u = Function(name='u', grid=grid, space_order=2)
+
+    eq_u = Eq(u, -(u*u).dxc, subdomain=sd0)
+
+    op = Operator(eq_u)
+    assert '--' not in str(op.ccode)
+
+
+def test_print_div():
+    a = SizeOf(np.int32)
+    b = SizeOf(np.int64)
+    cstr = ccode(a / b)
+    assert cstr == 'sizeof(int)/sizeof(long)'