Comments in assember output

[malc]

On Thu, 30 Nov 2006, Artur Krzysztof Szostak wrote:

>> I don't think there is any simple way to do this without using the -g
>> option.
>>
>> Note that the -g option does not affect code generation in any way.
>> You can use -O3 with or without -g, and you will get the same code.
>>
>
> Will the -g -O3 option truly give me code that executed at the same speed
> as -O3? I was not aware of that. In that case -g is fine. But even with -g I
> am not getting the result I want. I guess it is time for a specific example:
> Lets say I have the fillowing code in test.cxx
>
> float func(float a, float b)
> {
> 	return a * b;
> }
>

[..snip..]

Something like
<transcript>
cas$ g++ -c -g -O3 -Wa,-ahl=cas.s cas.c
cas$ sed -n /func/,40p cas.s
   12                    .globl _Z4funcff
   13                            .type   _Z4funcff, @function
   14                    _Z4funcff:
   15                    .LFB3:
   16                            .file 1 "cas.c"
    1:cas.c         **** float func(float a, float b)
    2:cas.c         **** {
   17                            .loc 1 2 0
   18                    .LVL0:
   19 0000 55                    pushl   %ebp
   20                    .LCFI0:
   21 0001 89E5                  movl    %esp, %ebp
   22                    .LCFI1:
   23 0003 D9450C                flds    12(%ebp)
    3:cas.c         ****         return a * b;
   24                            .loc 1 3 0
   25                    .LBB2:
   26 0006 D84D08                fmuls   8(%ebp)
    4:cas.c         **** }
   27                            .loc 1 4 0
   28 0009 5D                    popl    %ebp
   29 000a C3                    ret
   32                            .size   _Z4funcff, .-_Z4funcff
  215 0012 66756E63              .string "func"
  233 0006 66756E63              .string "func"
</transcript>

perhaps

-- 
vale