From dc9e958b0f8a9fb8eaa0f11acf75d6ed9bf3eb19 Mon Sep 17 00:00:00 2001
From: Ajax <commial@gmail.com>
Date: Fri, 23 Dec 2016 15:12:36 +0100
Subject: AAS sem: avoid an ExprOp('-', a, b)

---
 miasm2/arch/x86/sem.py | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

(limited to 'miasm2')

diff --git a/miasm2/arch/x86/sem.py b/miasm2/arch/x86/sem.py
index 5dc49efc..ced545be 100644
--- a/miasm2/arch/x86/sem.py
+++ b/miasm2/arch/x86/sem.py
@@ -2663,8 +2663,13 @@ def _tpl_aaa(ir, instr, op):
     cond |= af & i1
 
     to_add = m2_expr.ExprInt(0x106, size=r_ax.size)
-    new_ax = m2_expr.ExprOp(op, r_ax, to_add) & m2_expr.ExprInt(0xff0f,
-                                                                size=r_ax.size)
+    if op == "-":
+        # Avoid ExprOp("-", A, B), should be ExprOp("+", A, ExprOp("-", B))
+        first_part = r_ax - to_add
+    else:
+        first_part = m2_expr.ExprOp(op, r_ax, to_add)
+    new_ax = first_part & m2_expr.ExprInt(0xff0f,
+                                          size=r_ax.size)
     # set AL
     e.append(m2_expr.ExprAff(r_ax, m2_expr.ExprCond(cond, new_ax, r_ax)))
     e.append(m2_expr.ExprAff(af, cond))
-- 
cgit 1.4.1