Artur,
I just tried playing around with this, and it appears the the "-S" flag
is interfering. Perhaps by stopping the compilation process in that
way, it prevents the generation of the "listing file".
I tried compiling your example function as follows:
gcc -c -g -O3 -Wa,-adhls=func.list func.c
And got the following output (in func.list):
1 .file "func.c"
4 .text
5 Ltext0:
28 .p2align 4,,15
32 .globl _func
34 _func:
1:func.c **** float func( float a, float b )
2:func.c **** {
36 LM1:
37 0000 55 pushl %ebp
38 0001 89E5 movl %esp, %ebp
40 LM2:
41 0003 D9450C flds 12(%ebp)
3:func.c **** return a * b;
43 LM3:
44 0006 D84D08 fmuls 8(%ebp)
4:func.c **** }
46 LM4:
47 0009 5D popl %ebp
48 000a C3 ret
50 Lscope0:
52 .text
54 000b 90909090 Letext:
54 90
This appears to be the sort of output you are looking for, right?
--
Tony Wetmore
Solipsys Corporation (http://www.solipsys.com)
mailto:tony.wetmore@xxxxxxxxxxxx
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;
}
and try to generate the assembly with
g++ -g -O3 -Wa,-addhls test.cxx -S
I would get the following (This output is truncated, I left out all the debug
symbols at the end):
# ... bla bla bla...
.LFB2:
.file 1 "test.cxx"
.loc 1 3 0
.LVL0:
pushl %ebp
.LCFI0:
movl %esp, %ebp
.LCFI1:
.loc 1 3 0
flds 12(%ebp)
.LBB2:
.loc 1 4 0
fmuls 8(%ebp)
.LBE2:
.loc 1 5 0
leave
ret
.LFE2:
.size _Z4funcff, .-_Z4funcff
# ... etc ...
And I dont see any comments containing my c++ source lines. I would have
expected something like:
# ... bla bla bla...
.LFB2:
.file 1 "test.cxx"
.loc 1 3 0
# float func(float a, float b)
# {
.LVL0:
pushl %ebp
# return a * b;
.LCFI0:
movl %esp, %ebp
.LCFI1:
.loc 1 3 0
flds 12(%ebp)
.LBB2:
.loc 1 4 0
fmuls 8(%ebp)
.LBE2:
.loc 1 5 0
leave
ret
# }
.LFE2:
.size _Z4funcff, .-_Z4funcff
# ... etc ...
Any ideas how to get his kind of output?
