symbolic_hamsim_by_gqsp does not qubit count

[mpharrigan]

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
File ~/qutran/qutran/qualtran/resource_counting/_qubit_counts.py:110, in QubitCount.compute(self, bloq, get_callee_cost)
    109     logger.info("Computing %s for %s from its decomposition", self, bloq)
--> 110     return _cbloq_max_width(cbloq._binst_graph, get_callee_cost)
    111 except (DecomposeNotImplementedError, DecomposeTypeError):

File ~/qutran/qutran/qualtran/resource_counting/_qubit_counts.py:60, in _cbloq_max_width(binst_graph, _bloq_max_width)
     56 if not isinstance(binst, DanglingT):
     57     # During the application of the binst, we have "observer" connections that have
     58     # width as well as the width from the binst itself. We consider the case where
     59     # the bloq may have a max_width greater than the max of its left/right registers.
---> 60     during_size = _bloq_max_width(binst.bloq) + sum(s.shape for s in in_play)
     61     max_width = smax(max_width, during_size)

File ~/qutran/qutran/qualtran/resource_counting/_costing.py:142, in _get_cost_value.<locals>._get_cost_val_internal(callee)
    141 def _get_cost_val_internal(callee: 'Bloq'):
--> 142     return _get_cost_value(callee, cost_key, costs_cache=costs_cache, generalizer=generalizer)

File ~/qutran/qutran/qualtran/resource_counting/_costing.py:146, in _get_cost_value(bloq, cost_key, costs_cache, generalizer)
    145 tstart = time.perf_counter()
--> 146 computed_cost = cost_key.compute(bloq, _get_cost_val_internal)
    147 tdur = time.perf_counter() - tstart

File ~/qutran/qutran/qualtran/resource_counting/_qubit_counts.py:123, in QubitCount.compute(self, bloq, get_callee_cost)
    122 min_bloq_size = bloq.signature.n_qubits()
--> 123 callees = get_bloq_callee_counts(bloq)
    124 tot: int = min_bloq_size

File ~/qutran/qutran/qualtran/resource_counting/_call_graph.py:122, in get_bloq_callee_counts(bloq, generalizer, ssa, ignore_decomp_failure)
    121 try:
--> 122     return _generalize_callees(bloq.build_call_graph(ssa), cast(GeneralizerT, generalizer))
    123 except (DecomposeNotImplementedError, DecomposeTypeError) as e:

File ~/qutran/qutran/qualtran/bloqs/qsp/generalized_qsp.py:383, in GeneralizedQSP.build_call_graph(self, ssa)
    381 counts[self.U.adjoint().controlled()] += smin(degree, self.negative_power)
--> 383 return set((bloq, count) for bloq, count in counts.items() if not is_zero(count))

File ~/qutran/qutran/qualtran/bloqs/qsp/generalized_qsp.py:383, in <genexpr>(.0)
    381 counts[self.U.adjoint().controlled()] += smin(degree, self.negative_power)
--> 383 return set((bloq, count) for bloq, count in counts.items() if not is_zero(count))

File ~/qutran/qutran/qualtran/symbolics/math_funcs.py:326, in is_zero(x)
    325 if is_symbolic(x):
--> 326     return x.equals(0)
    327 return x == 0

File ~/qutran/py311-cf/lib/python3.11/site-packages/sympy/core/expr.py:757, in Expr.equals(self, other, failing_expression)
    755         return any(fac_zero)
--> 757 constant = diff.is_constant(simplify=False, failing_number=True)
    759 if constant is False:

File ~/qutran/py311-cf/lib/python3.11/site-packages/sympy/core/expr.py:661, in Expr.is_constant(self, *wrt, **flags)
    660 try:
--> 661     a = expr.subs(list(zip(free, [0]*len(free))),
    662         simultaneous=True)
    663     if a is S.NaN:
    664         # evaluation may succeed when substitution fails

File ~/qutran/py311-cf/lib/python3.11/site-packages/sympy/core/basic.py:1036, in Basic.subs(self, *args, **kwargs)
   1035     reps[m] = S.One  # get rid of m
-> 1036     return rv.xreplace(reps)
   1037 else:

File ~/qutran/py311-cf/lib/python3.11/site-packages/sympy/core/basic.py:1230, in Basic.xreplace(self, rule)
   1169 """
   1170 Replace occurrences of objects within the expression.
   1171 
   (...)
   1228 
   1229 """
-> 1230 value, _ = self._xreplace(rule)
   1231 return value

File ~/qutran/py311-cf/lib/python3.11/site-packages/sympy/core/basic.py:1252, in Basic._xreplace(self, rule)
   1251     if changed:
-> 1252         return self.func(*args), True
   1253 return self, False

File ~/qutran/py311-cf/lib/python3.11/site-packages/sympy/core/cache.py:72, in __cacheit.<locals>.func_wrapper.<locals>.wrapper(*args, **kwargs)
     71 try:
---> 72     retval = cfunc(*args, **kwargs)
     73 except TypeError as e:

File ~/qutran/py311-cf/lib/python3.11/site-packages/sympy/series/order.py:154, in Order.__new__(cls, expr, *args, **kwargs)
    153 if not all(v.is_symbol for v in variables):
--> 154     raise TypeError('Variables are not symbols, got %s' % variables)
    156 if len(list(uniq(variables))) != len(variables):

TypeError: Variables are not symbols, got [0, 1]

The above exception was the direct cause of the following exception:

RuntimeError                              Traceback (most recent call last)
Cell In[14], line 4
      2 be = get_bloq_example('symbolic_hamsim_by_gqsp')
      3 bloq = be.make()
----> 4 show_call_graph(bloq, max_depth=1)

File ~/qutran/qutran/qualtran/drawing/_show_funcs.py:120, in show_call_graph(item, max_depth, agg_gate_counts)
    102 """Display a graph representation of the call graph.
    103 
    104 Args:
   (...)
    116 
    117 """
    118 if isinstance(item, Bloq):
    119     IPython.display.display(
--> 120         GraphvizCallGraph.from_bloq(
    121             item, max_depth=max_depth, agg_gate_counts=agg_gate_counts
    122         ).get_svg()
    123     )
    124 else:
    125     IPython.display.display(GraphvizCounts(item).get_svg())

File ~/qutran/qutran/qualtran/drawing/bloq_counts_graph.py:330, in GraphvizCallGraph.from_bloq(cls, bloq, max_depth, agg_gate_counts)
    327 from qualtran.resource_counting import QECGatesCost, QubitCount, query_costs
    329 call_graph, _ = bloq.call_graph(max_depth=max_depth)
--> 330 cost_data: Dict['Bloq', Dict[CostKey, Any]] = query_costs(
    331     bloq, [QubitCount(), QECGatesCost()]
    332 )
    333 formatted_cost_data = cls.format_cost_data(cost_data, agg_gate_counts=agg_gate_counts)
    334 return cls(g=call_graph, bloq_data=formatted_cost_data)

File ~/qutran/qutran/qualtran/resource_counting/_costing.py:249, in query_costs(bloq, cost_keys, generalizer)
    247 costs: Dict['Bloq', Dict[CostKey, CostValT]] = defaultdict(dict)
    248 for cost_key in cost_keys:
--> 249     cost_for_bloqs = get_cost_cache(bloq, cost_key, generalizer=generalizer)
    250     for bloq, val in cost_for_bloqs.items():
    251         costs[bloq][cost_key] = val

File ~/qutran/qutran/qualtran/resource_counting/_costing.py:220, in get_cost_cache(bloq, cost_key, costs_cache, generalizer)
    217 if isinstance(generalizer, collections.abc.Sequence):
    218     generalizer = _make_composite_generalizer(*generalizer)
--> 220 _get_cost_value(bloq, cost_key, costs_cache=costs_cache, generalizer=generalizer)
    221 return costs_cache

File ~/qutran/qutran/qualtran/resource_counting/_costing.py:146, in _get_cost_value(bloq, cost_key, costs_cache, generalizer)
    144 # part b. call the compute method and cache the result.
    145 tstart = time.perf_counter()
--> 146 computed_cost = cost_key.compute(bloq, _get_cost_val_internal)
    147 tdur = time.perf_counter() - tstart
    148 logger.info("Computed %s for %s in %g s", cost_key, bloq, tdur)

File ~/qutran/qutran/qualtran/resource_counting/_qubit_counts.py:114, in QubitCount.compute(self, bloq, get_callee_cost)
    112     pass
    113 except Exception as e:
--> 114     raise RuntimeError(
    115         f"An unexpected error occurred when trying to compute {self} for {bloq}: {e}"
    116     ) from e
    118 # Fallback:
    119 # Use the simple maximum of callees and of this bloq's signature. If there
    120 # are no callees, this will be the number of qubits implied by the signature.
    121 # In any case, this strategy is likely an under-estimate of the qubit count.
    122 min_bloq_size = bloq.signature.n_qubits()

RuntimeError: An unexpected error occurred when trying to compute qubit count for HamiltonianSimulationByGQSP: Variables are not symbols, got [0, 1]

It seems that the is_zero function is choking on some counts in GeneralizedQSP.build_call_graph

@anurudhp changed this recently can you investigate