x86_64

x86_64

[Ananda Bhattacharya]

Hi,
	This is a pretty simple quesion, I was wondering if 
anyone here compiled povray on an Opteron, and if so what 
flags were uses in the Makefie CFLAGS and CXFLAGS options.

I just cannot get it to compile any help regarding this 
matter will be great. 

Here is the error that i am getting 

Making all in src
make[1]: Entering directory 
`/arnold/keg/anandab/download/povray-3.50c/src'
c++ -DPREFIX=\"/usr/local\" 
-DPOV_LIB_DIR=\"/usr/local/share/povray-3.5\" 
-DCOMPILER_VER=\".Linux.gcc\" 
-DSYSCONFDIR=\"/usr/local/etc\" -DUSE_IO_RESTRICTIONS=\"\"     
`if [ "Xgcc" = "Xgcc" ]; then echo "-Wno-multichar"; fi ` 
-O3 -finline-functions -ffast-math -fomit-frame-pointer 
-funroll-loops -fexpensive-optimizations  
-foptimize-sibling-calls -minline-all-stringops 
-Wno-multichar  -c bbox.cpp
In file included from bbox.cpp:47:
optout.h:49:2: #error You must complete the following 
DISTRIBUTION_MESSAGE macro
bbox.cpp: In function `int sort_and_split(BBOX_TREE**, 
BBOX_TREE**&, long int*, 
   long int, long int)':
bbox.cpp:1872: warning: assignment to `long int' from 
`double'
bbox.cpp:1872: warning: argument to `long int' from `double'
make[1]: *** [bbox.o] Error 1


##################################################
What should my correct compiler flags be. 
thanks 

PS this might be a trivial problem so sorry for bothering 
anyone. 
-Ananda 



-- 
Recruiter: "How do you write a perl script?"
Canidate : "You type it."
	-Actual phone interview, Circa Nov 2003

Re: x86_64

[Andrew Haley]

Bob Plantz wrote:
> On Mon, 2009-01-19 at 18:34 +0000, Andrew Haley wrote:
> 
>> http://refspecs.freestandards.org/elf/x86_64-abi-0.95.pdf

> 
> v0.99 is available at
> 
> http://www.x86-64.org/documentation.html

Yeah, thanks.  I've tried to persuade the LSB to update that link,
but the ABI is frozen at that version, bugs and all.

Andrew.

Re: x86_64

[Bob Plantz]

On Mon, 2009-01-19 at 18:34 +0000, Andrew Haley wrote:

> 
> http://refspecs.freestandards.org/elf/x86_64-abi-0.95.pdf
> 
> Andrew.
> 

v0.99 is available at

http://www.x86-64.org/documentation.html

Bob

Re: x86_64

[Andrew Haley]

John Fine wrote:
> Andrew Haley wrote:
>> Yang Zhang wrote:
>>  
>>> The x86_64 output also sports a .section eh_frame despite the fact that
>>> I'm not using g++, which seems to just contain some data layout
>>> description of the above labeled items.
>>>     
>>
>> I presume you saw my reply; all the answers are there.
>>
>>   
> 
> Was that content that shouldn't go to the mailing list for some reason?

Not at all; I don't know why the reply didn't go to the list

The reply was:

Start at

http://refspecs.freestandards.org/

then

http://refspecs.freestandards.org/elf/x86_64-abi-0.95.pdf

Andrew.

Re: x86_64

[John Fine]

Andrew Haley wrote:
> Yang Zhang wrote:
>   
>> The x86_64 output also sports a .section eh_frame despite the fact that
>> I'm not using g++, which seems to just contain some data layout
>> description of the above labeled items.
>>     
>
> I presume you saw my reply; all the answers are there.
>
>   

Was that content that shouldn't go to the mailing list for some reason?

I know a fair amount of this stuff myself already, but not so much that 
I don't want to learn more.  Also, someone finding this question later 
by a search of the mailing list archive might want to see the answers as 
well.
(Your reply with answers is not visible at 
http://gcc.gnu.org/ml/gcc-help/2009-01/ )

Re: x86_64

[Yang Zhang]

Andrew Haley wrote:
> Yang Zhang wrote:
>> John Fine wrote:
>>> If you understand the 32-bit and you can read the AMD manuals, I don't
>>> see what else might be confusing you (actually even the above register
>>> lists were in one of the AMD manuals).
>>>
>>> What is confusing about the use of local labels by the compiler?
>> There are many of these labels in the x86_64 output and none in the x86
>> output.  I can't piece together how they're being used.
>>
>> The x86_64 output also sports a .section eh_frame despite the fact that
>> I'm not using g++, which seems to just contain some data layout
>> description of the above labeled items.
> 
> I presume you saw my reply; all the answers are there.
> 
> Andrew.

Yes, thanks - I'm looking through it now.
-- 
Yang Zhang
http://www.mit.edu/~y_z/

Re: x86_64

[Andrew Haley]

Yang Zhang wrote:
> John Fine wrote:
>> If you understand the 32-bit and you can read the AMD manuals, I don't
>> see what else might be confusing you (actually even the above register
>> lists were in one of the AMD manuals).
>>
>> What is confusing about the use of local labels by the compiler?
> 
> There are many of these labels in the x86_64 output and none in the x86
> output.  I can't piece together how they're being used.
> 
> The x86_64 output also sports a .section eh_frame despite the fact that
> I'm not using g++, which seems to just contain some data layout
> description of the above labeled items.

I presume you saw my reply; all the answers are there.

Andrew.

Re: x86_64

[Bob Plantz]

On Mon, 2009-01-19 at 05:16 -0500, Yang Zhang wrote:
> Are there any good resources for learning about gcc's x86_64 assembly 
> output?  When I run `gcc -S a.c` for a simple test C program like the 
> one below, I can completely understand the resulting go.s on a 32-bit 
> x86, but as soon as I run that on a 64-bit machine, I'm lost.  I know 
> what the instructions are (i.e. I know how to use the AMD manuals), but 
> I'd like to learn about gcc's assembly output: the exact new calling 
> conventions (registers seem to be more liberally used over the stack now 
> even without opt), all these 
> .LFB/.LCFI/.LFE/.Lframe/.LSCIE/.LSFDE/.LASFDE/... labels, and so on. 
> Thanks in advance for any guidance.
> 
> void foo(int a, int b, int c) { char xs[5]; char ys[10]; }
> int main() { foo(1,2,3); return 0; }
> 

Many of the local labels you see are coming from the DWARF2 unwind
table. I don't know a lot about it, but I believe it's used for
exception processing, for example, using a debugger.

You can eliminate this table with the following options:

$ gcc -O0 -g -Wa,-adhls -fno-asynchronous-unwind-tables \
> myProg.c > myProg.lst

These options will also provide some comments in the assembly listing
that refer back to the C source code. This should help you "cut to the
chase" in trying to figure this out.

Bob Plantz

Re: x86_64

[Yang Zhang]

John Fine wrote:
> If you understand the 32-bit and you can read the AMD manuals, I don't 
> see what else might be confusing you (actually even the above register 
> lists were in one of the AMD manuals).
> 
> What is confusing about the use of local labels by the compiler?

There are many of these labels in the x86_64 output and none in the x86 
output.  I can't piece together how they're being used.

The x86_64 output also sports a .section eh_frame despite the fact that 
I'm not using g++, which seems to just contain some data layout 
description of the above labeled items.

I'm using gcc 4.3.2 if that matters.

Yang

Re: x86_64

[John Fine]

I forget where it is documented.  I have the following two register 
lists taped on the bottom bezel of one of my CRT's, because I debug a 
lot of C++ code in assembler view and this key part of the calling 
convention is important whenever you debug C++ in assembler view:

1) Parameters passed in registers, left to right:  rdi, rsi, rdx, rcx, 
r8, r9
2) registers preserved by call:  rbp, rbx, r12-r15

so in your example, assuming foo was NOT optimized to be inline, "a" 
would be passed in rdi, "b" would be passed in rsi and "c" would be 
passed in rdx.

Obviously it gets more complicated when you mix in data types other than 
pointers and integers.  Also, I hope obvious, in member functions "this" 
is passed in as if it were the leftmost parameter.

If you understand the 32-bit and you can read the AMD manuals, I don't 
see what else might be confusing you (actually even the above register 
lists were in one of the AMD manuals).

What is confusing about the use of local labels by the compiler?


Yang Zhang wrote:
> Are there any good resources for learning about gcc's x86_64 assembly 
> output?  When I run `gcc -S a.c` for a simple test C program like the 
> one below, I can completely understand the resulting go.s on a 32-bit 
> x86, but as soon as I run that on a 64-bit machine, I'm lost.  I know 
> what the instructions are (i.e. I know how to use the AMD manuals), 
> but I'd like to learn about gcc's assembly output: the exact new 
> calling conventions (registers seem to be more liberally used over the 
> stack now even without opt), all these 
> .LFB/.LCFI/.LFE/.Lframe/.LSCIE/.LSFDE/.LASFDE/... labels, and so on. 
> Thanks in advance for any guidance.
>
> void foo(int a, int b, int c) { char xs[5]; char ys[10]; }
> int main() { foo(1,2,3); return 0; }
>

x86_64

[Yang Zhang]

Are there any good resources for learning about gcc's x86_64 assembly 
output?  When I run `gcc -S a.c` for a simple test C program like the 
one below, I can completely understand the resulting go.s on a 32-bit 
x86, but as soon as I run that on a 64-bit machine, I'm lost.  I know 
what the instructions are (i.e. I know how to use the AMD manuals), but 
I'd like to learn about gcc's assembly output: the exact new calling 
conventions (registers seem to be more liberally used over the stack now 
even without opt), all these 
.LFB/.LCFI/.LFE/.Lframe/.LSCIE/.LSFDE/.LASFDE/... labels, and so on. 
Thanks in advance for any guidance.

void foo(int a, int b, int c) { char xs[5]; char ys[10]; }
int main() { foo(1,2,3); return 0; }

-- 
Yang Zhang
http://www.mit.edu/~y_z/