Re: [PATCH 4/5] perf, tools, script: Add support for printing assembler

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Mon, Jan 23, 2017 at 11:55:21AM -0800, Andi Kleen escreveu:
> > Do you know if there is any tool comparing the output of objdump -d to what is
> > produced by a similar xed based tool?
> 
> I'm not aware of such a tool, but could be written using the "xed" tool
> in the xed distribution. However I would trust xed over objdump,

It would go both ways, and I was not implying which one is "better",
just checking differences in the output.

> it is used widely in Intel tools with likely far more testing
> than binutils
> 
> >   4b8506  jz 0x4b84d0 <perf_evsel__enable+0x70>      74 c8                 je     4b84d0 <perf_evsel__enable+0x70>
> >   4b84d0  add $0x1, %r14                                                   add    $0x1,%r14
> >   4b84d4  cmp %r14d, %ebx                                                  cmp    %r14d,%ebx
> >   4b84d7  jle 0x4b8530 <perf_evsel__enable+0xd0>                           jle    4b8530 <perf_evsel__enable+0xd0>
> >   4b8530  add $0x1, %r12                                                   add    $0x1,%r12
> >   4b8534  cmp %r12d, %r13d                                                 cmp    %r12d,%r13d
> >   4b8537  jnle 0x4b84c2 <perf_evsel__enable+0x62>    7f 89                 jg     4b84c2 <perf_evsel__enable+0x62>
> >   4b84c2  xor %r14d, %r14d                                                 xor    %r14d,%r14d
> >   4b84c5  test %ebx, %ebx                                                  test   %ebx,%ebx
> >   4b84c7  jnle 0x4b84d9 <perf_evsel__enable+0x79>    7f 10                 jg     4b84d9 <perf_evsel__enable+0x79>
> >   4b84d9  movq  0x90(%r15), %rax                     49 8b 87 90 00 00 00  mov    0x90(%r15),%rax
> >   4b84e0  mov %r12, %rdx                                                   mov    %r12,%rdx
> >   4b84e3  mov %r14, %rcx                                                   mov    %r14,%rcx
> >   4b84e6  mov $0x2400, %esi                                                mov    $0x2400,%esi
> >   4b84eb  imulq  (%rax), %rdx                        48 0f af 10           imul   (%rax),%rdx
> >   4b84ef  imulq  0x8(%rax), %rcx                     48 0f af 48 08        imul   0x8(%rax),%rcx
> >   4b84f4  add %rdx, %rax                                                   add    %rdx,%rax
> >   4b84f7  xor %edx, %edx                                                   xor    %edx,%edx
> >   4b84f9  movl  0x18(%rcx,%rax,1), %edi              8b 7c 01 18           mov    0x18(%rcx,%rax,1),%edi
> >   4b84fd  xor %eax, %eax                                                   xor    %eax,%eax
> >   4b84ff  callq  0x42d990 <ioctl@plt>                                      callq  42d990 <ioctl@plt>
> >   4b8504  test %eax, %eax                                                  test   %eax,%eax
> >   4b8506  jz 0x4b84d0 <perf_evsel__enable+0x70>      74 c8                 je     4b84d0 <perf_evsel__enable+0x70>
> 
> Yes all the differences are ok. It's just synonyms of the instructions.
> 
> -Andi