"not" doesn't affect flags, "xor $-1" does.

diff --git a/src/arch/i386/prefix/unnrv2b.S b/src/arch/i386/prefix/unnrv2b.S
index 50776dc..d62441a 100644 (file)
--- a/src/arch/i386/prefix/unnrv2b.S
+++ b/src/arch/i386/prefix/unnrv2b.S
@@ -128,7 +128,7 @@ loop1_n2b:
        shl     $8, %xAX        
        movb    (%xSI), %al     /* m_off = (m_off - 3)*256 + src[ilen++] */
        inc     %xSI
-       not     %xAX    
+       xor     $-1, %xAX
        jz      decompr_end_n2b /* if (m_off == 0xffffffff) goto decomp_end_n2b */
        mov     %xAX, %xBP      /* last_m_off = m_off ?*/
 decompr_ebpeax_n2b: