Re: je,pn : Is it an intel instruction ?

[Sandeep Kumar <sandeepksinha at gmail dot com>]

On 2/8/06, H. J. Lu <hjl@lucon.org> wrote:
> On Wed, Feb 08, 2006 at 07:28:37PM +0530, Sandeep Kumar wrote:
> > Hello everyone,
> > While using objdump with the -S option the assembly for the above code is shown
> >
> > 2e 74 c0          je,pn 8048....
> >
> > 2e is a cs_  prefix and 74 is opcode for jmp with 8 bit displacement.
> >
> > Then why is the objdump showing : je,pn . Does it have some other
> > significance ?
> > Is je,pn an instruction in intel machines ?
> > We can also see je,pa at places.
> >
> > And where is the cs : prefix gone in the assembly source code ?
>
> Do you have .s and .o to show this?
>
>
> H.J.
>

[root@OpenDos ~]# objdump -S  /usr/bin/bc

After executing this, this is the part of the output....

 8049733:       83 ad 30 fb ff ff 02    subl   $0x2,0xfffffb30(%ebp)
 804973a:       83 ad 2c fb ff ff 04    subl   $0x4,0xfffffb2c(%ebp)
 8049741:       8b 85 30 fb ff ff       mov    0xfffffb30(%ebp),%eax
 8049747:       0f bf 18                movswl (%eax),%ebx
 804974a:       0f bf 9c 1b a0 2d 05    movswl 0x8052da0(%ebx,%ebx,1),%ebx
 8049751:       08
 8049752:       81 fb 00 80 ff ff       cmp    $0xffff8000,%ebx
 8049758:       89 9d 34 fb ff ff       mov    %ebx,0xfffffb34(%ebp)
 804975e:       2e 74 c0                je,pn  8049721 <strcpy@plt+0x9a5>
 8049761:       83 85 34 fb ff ff 01    addl   $0x1,0xfffffb34(%ebp)
 8049768:       81 bd 34 fb ff ff b5    cmpl   $0x2b5,0xfffffb34(%ebp)
 804976f:       02 00 00
 8049772:       2e 77 ac                ja,pn  8049721 <strcpy@plt+0x9a5>
 8049775:       8b 95 34 fb ff ff       mov    0xfffffb34(%ebp),%edx
 804977b:       66 83 bc 12 e0 26 05    cmpw   $0x1,0x80526e0(%edx,%edx,1)
 8049782:       08 01


--
Regards,
Sandeep


A man with one watch knows what time it is; a man with two watches is
never quite sure.