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RE: [PATCH 2/3] record-btrace, disas: omit pc prefix
> -----Original Message-----
> From: Jan Kratochvil [mailto:jan.kratochvil@redhat.com]
> Sent: Wednesday, February 27, 2013 8:59 AM
> To: Metzger, Markus T
> Cc: gdb-patches@sourceware.org; markus.t.metzger@gmail.com
> Subject: Re: [PATCH 2/3] record-btrace, disas: omit pc prefix
>
> On Mon, 25 Feb 2013 17:15:16 +0100, markus.t.metzger@intel.com wrote:
> > From: Markus Metzger <markus.t.metzger@intel.com>
> >
> > Add a disassembly flag to omit the pc prefix and use it in the "record
> > instruction-history" command of record-btrace.
> >
> > The pc prefix would appear multiple times in the branch trace disassembly,
> > which is more confusing than helpful.
>
> I do not see it, moreover I find the output better without this patch:
Within a loop, you will see repeating => very frequently.
(gdb) rec inst -
0x00000000004006ec <_ZL4loopPv+8>: mov 0x200955(%rip),%rax # 0x601048 <_ZL6shared>
=> 0x00000000004006f3 <_ZL4loopPv+15>: add $0x1,%rax
0x00000000004006f7 <_ZL4loopPv+19>: mov %rax,0x20094a(%rip) # 0x601048 <_ZL6shared>
0x00000000004006fe <_ZL4loopPv+26>: jmp 0x4006ec <_ZL4loopPv+8>
0x00000000004006ec <_ZL4loopPv+8>: mov 0x200955(%rip),%rax # 0x601048 <_ZL6shared>
=> 0x00000000004006f3 <_ZL4loopPv+15>: add $0x1,%rax
0x00000000004006f7 <_ZL4loopPv+19>: mov %rax,0x20094a(%rip) # 0x601048 <_ZL6shared>
0x00000000004006fe <_ZL4loopPv+26>: jmp 0x4006ec <_ZL4loopPv+8>
0x00000000004006ec <_ZL4loopPv+8>: mov 0x200955(%rip),%rax # 0x601048 <_ZL6shared>
=> 0x00000000004006f3 <_ZL4loopPv+15>: add $0x1,%rax
(gdb)
[...]
> (gdb) record instruction-history
> warning: Recorded trace may be corrupted.
> warning: Recorded trace may be corrupted.
> warning: Recorded trace may be corrupted.
That's unexpected. If you can reproduce this, would you please send
me the reproducer so I can have a look at it?
[...]
Thanks,
Markus.
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