Use faster xreplace everywhere.

2 files changed, 2 insertions, 2 deletions

diff --git a/pyecsca/ec/curve.py b/pyecsca/ec/curve.py
index fedf65f..ff89819 100644
--- a/pyecsca/ec/curve.py
+++ b/pyecsca/ec/curve.py
@@ -121,7 +121,7 @@ class EllipticCurve:
                 expr = sympify(f"{rhs} - {lhs}")
                 for symbol in expr.free_symbols:
                     if (val := self.parameters.get(str(symbol), None)) is not None:
-                        expr = expr.subs(symbol, val)
+                        expr = expr.xreplace({symbol: val})
                 if len(expr.free_symbols) > 0:
                     raise ValueError(
                         f"Missing necessary coordinate model parameter ({assumption_string})."
diff --git a/pyecsca/ec/formula/unroll.py b/pyecsca/ec/formula/unroll.py
index 83a7517..3c63e00 100644
--- a/pyecsca/ec/formula/unroll.py
+++ b/pyecsca/ec/formula/unroll.py
@@ -39,7 +39,7 @@ def unroll_formula_expr(formula: Formula) -> List[Tuple[str, Expr]]:
             # Handle a symbolic assignment to a new parameter.
             expr = sympify(rhs, evaluate=False)
             for curve_param, value in params.items():
-                expr = expr.subs(curve_param, value)
+                expr = expr.xreplace({curve_param: value})
             params[lhs] = expr
 
     locls = {**params, **inputs}