Merge pull request #887 from w4kfu/shld_shrd_fix_mask_count

X86 SEM SH[LR]D : use masked count for all expression in _shift_tpl

1 files changed, 4 insertions, 4 deletions

diff --git a/miasm2/arch/x86/sem.py b/miasm2/arch/x86/sem.py
index 939cd400..b8317ea7 100644
--- a/miasm2/arch/x86/sem.py
+++ b/miasm2/arch/x86/sem.py
@@ -735,9 +735,9 @@ def _shift_tpl(op, ir, instr, a, b, c=None, op_inv=None, left=False,
 
         # An overflow can occured, emulate the 'undefined behavior'
         # Overflow behavior if (shift / size % 2)
-        base_cond_overflow = c if left else (
-            c - m2_expr.ExprInt(1, size=c.size))
-        cond_overflow = base_cond_overflow & m2_expr.ExprInt(a.size, c.size)
+        base_cond_overflow = shifter if left else (
+            shifter - m2_expr.ExprInt(1, size=shifter.size))
+        cond_overflow = base_cond_overflow & m2_expr.ExprInt(a.size, shifter.size)
         if left:
             # Overflow occurs one round before right
             mask = m2_expr.ExprCond(cond_overflow, mask, ~mask)
@@ -750,7 +750,7 @@ def _shift_tpl(op, ir, instr, a, b, c=None, op_inv=None, left=False,
 
         # Overflow case: cf come from src (bit number shifter % size)
         cf_from_src = m2_expr.ExprOp(op, b,
-                                     (c.zeroExtend(b.size) &
+                                     (shifter.zeroExtend(b.size) &
                                       m2_expr.ExprInt(a.size - 1, b.size)) - i1)
         cf_from_src = cf_from_src.msb() if left else cf_from_src[:1]
         new_cf = m2_expr.ExprCond(cond_overflow, cf_from_src, cf_from_dst)