Expression: add simp cond

2 files changed, 15 insertions, 0 deletions

diff --git a/miasm2/expression/simplifications.py b/miasm2/expression/simplifications.py
index d3628ae8..e090d806 100644
--- a/miasm2/expression/simplifications.py
+++ b/miasm2/expression/simplifications.py
@@ -56,6 +56,9 @@ class ExpressionSimplifier(object):
             simplifications_common.simp_cond_flag,
             simplifications_common.simp_cond_int,
             simplifications_common.simp_cmp_int_arg,
+
+            simplifications_common.simp_cond_eq_zero,
+
         ],
         m2_expr.ExprMem: [simplifications_common.simp_mem],
 
diff --git a/miasm2/expression/simplifications_common.py b/miasm2/expression/simplifications_common.py
index b01b1d1d..2bdccdbd 100644
--- a/miasm2/expression/simplifications_common.py
+++ b/miasm2/expression/simplifications_common.py
@@ -1021,3 +1021,15 @@ def simp_zeroext_eq_cst(expr_s, expr):
         # Always false
         return ExprInt(0, 1)
     return ExprOp("==", src, ExprInt(int(arg2), src.size))
+
+
+def simp_cond_eq_zero(expr_s, expr):
+    # (X == 0)?(A:B) => X?(B:A)
+    cond = expr.cond
+    if not cond.is_op('=='):
+        return expr
+    arg1, arg2 = cond.args
+    if not arg2.is_int(0):
+        return expr
+    new_expr = ExprCond(arg1, expr.src2, expr.src1)
+    return new_expr