diff options
Diffstat (limited to '')
| -rw-r--r-- | miasm2/arch/x86/sem.py | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/miasm2/arch/x86/sem.py b/miasm2/arch/x86/sem.py index 635206b6..6dcc76af 100644 --- a/miasm2/arch/x86/sem.py +++ b/miasm2/arch/x86/sem.py @@ -4212,6 +4212,31 @@ def _signed_saturation(expr, dst_size): ) +def _unsigned_saturation(expr, dst_size): + """Saturate the expr @expr for @dst_size bit + Unsigned saturation return MAX_INT or value depending on the value + """ + assert expr.size > dst_size + + zero = m2_expr.ExprInt(0, dst_size) + max_int = m2_expr.ExprInt(-1, dst_size) + value = expr[:dst_size] + signed = expr.msb() + + + # Bit hack: to avoid a double signed comparison, use mask + # ie., in unsigned, 0xXY > 0x0f iff X is not null + + return m2_expr.ExprCond( + signed, + zero, + m2_expr.ExprCond(expr[dst_size:], + max_int, + value), + ) + + + def packsswb(ir, instr, dst, src): out = [] for source in [dst, src]: @@ -4220,6 +4245,13 @@ def packsswb(ir, instr, dst, src): return [m2_expr.ExprAff(dst, m2_expr.ExprCompose(*out))], [] +def packuswb(ir, instr, dst, src): + out = [] + for source in [dst, src]: + for start in xrange(0, dst.size, 16): + out.append(_unsigned_saturation(source[start:start + 16], 8)) + return [m2_expr.ExprAff(dst, m2_expr.ExprCompose(*out))], [] + mnemo_func = {'mov': mov, 'xchg': xchg, @@ -4719,6 +4751,7 @@ mnemo_func = {'mov': mov, "pmovmskb": pmovmskb, "packsswb": packsswb, + "packuswb": packuswb, "smsw": smsw, |