Re: [PATCH v4 2/2] perf report: Implement visual marker for macro fusion in annotate

[Arnaldo Carvalho de Melo]

Em Fri, Jul 07, 2017 at 01:06:35PM +0800, Jin Yao escreveu:
> For marking the fused instructions clearly, This patch adds a line
> before the first instruction of pair and joins it with the arrow of the
> jump.
> 
> For example, when je is selected in annotate view, the line before cmpl
> is displayed and joins the arrow of je.
> 
>        â   âââcmpl   $0x0,argp_program_version_hook
>  81.93 â   âââje     20
>        â   â  lock   cmpxchg %esi,0x38a9a4(%rip)
>        â   ââ jne    29
>        â   ââ jmp    43
>  11.47 â20:âââcmpxch %esi,0x38a999(%rip)
> 
> That means the cmpl+je is fused instruction pair and they should be
> considered together.

I applied this one, no unnecessary parsing of cpuid done at each
jump->target arrow rendering, much better, thanks!

One thing for a follow up patch:

We have this when the cursor is at a jump instruction:

       â      âââtest   %ecx,%ecx
->     â      âââje     714cf
       â      â  mov    LINES+0xb40,%edx
       â      â  test   %edx,%edx
       â      ââ je     71580
       â714cf:âââmov    LINES+0x10c8,%eax

But if we go up a line, to that "test" instruction, we get:

->     â         test   %ecx,%ecx
       â       â je     714cf
       â         mov    LINES+0xb40,%edx
       â         test   %edx,%edx
       â       â je     71580
       â714cf:   mov    LINES+0x10c8,%eax

I suggest that this be changed to:

->     â       ââtest   %ecx,%ecx
       â       â je     714cf
       â         mov    LINES+0xb40,%edx
       â         test   %edx,%edx
       â       â je     71580
       â714cf:   mov    LINES+0x10c8,%eax

I.e. even before going to the jump instruction line with the cursor, we
would see the fused instructions.

To do that perhaps we should improve annotate_browser__draw_current_jump
to improve that part that looks for is_valid_jump() to consider
instructions that could be fused with jumps for the machine where the
perf data came from, etc.

But the current situation is better already, thanks for your work,
applied!

- Arnaldo