Altivec doesn't work?

Altivec doesn't work?

[Décio Luiz Gazzoni Filho]

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Hello,

I have `GNU gdb 6.1-20040303 (Apple version gdb-413)' running on Mac  
OS X 10.4.2. I wrote some Altivec code and tried to load it into gdb.  
Although gdb can print the vector registers, they are not updated by  
any instructions that are run: all regs stay at the value  
0x7FFFDEAD7FFFDEAD7FFFDEAD7FFFDEAD.

I believe it's not a compilation issue, or a processor issue (mine is  
an MPC7447). Outside of gdb, the code seems to run fine (doesn't give  
an invalid instruction exception).

This is my first foray into Altivec programming, so I'm wondering  
what I'm missing here? This can't be a bug as Google doesn't turn  
anything up.

Décio

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Re: Altivec doesn't work?

[Daniel Jacobowitz]

On Sat, Jul 16, 2005 at 03:00:18PM -0300, Décio Luiz Gazzoni Filho wrote:
> Hello,
> 
> I have `GNU gdb 6.1-20040303 (Apple version gdb-413)' running on Mac  
> OS X 10.4.2.

You're going to have to ask Apple about this - that version of GDB is
very heavily modified by Apple, and current GDB still does not support
Mac OS X.

-- 
Daniel Jacobowitz
CodeSourcery, LLC

Re: Altivec doesn't work?

[Jason Molenda]

Daniel was correct that this isn't the right forum for Apple gdb  
questions.  Please send these kinds of things to xcode- 
users@lists.apple.com.

You'll want to be more specific about your program that isn't working  
under gdb.  For instance, this works fine with gdb-413:

#include <altivec.h>
int main () {
   vector unsigned int x = ((vector unsigned int) vec_splat_u8 (-2));
}

(gdb) p/x x
$2 = {0xfefefefe, 0xfefefefe, 0xfefefefe, 0xfefefefe}
(gdb)

Please follow up on xcode-users@ if you have any questions or  
problems with the Apple tools.  Thanks!

Jason

On Jul 16, 2005, at 11:00 AM, Décio Luiz Gazzoni Filho wrote:

> Hello,
>
> I have `GNU gdb 6.1-20040303 (Apple version gdb-413)' running on  
> Mac OS X 10.4.2. I wrote some Altivec code and tried to load it  
> into gdb. Although gdb can print the vector registers, they are not  
> updated by any instructions that are run: all regs stay at the  
> value 0x7FFFDEAD7FFFDEAD7FFFDEAD7FFFDEAD.
>
> I believe it's not a compilation issue, or a processor issue (mine  
> is an MPC7447). Outside of gdb, the code seems to run fine (doesn't  
> give an invalid instruction exception).
>
> This is my first foray into Altivec programming, so I'm wondering  
> what I'm missing here? This can't be a bug as Google doesn't turn  
> anything up.
>
> Décio

Re: Altivec doesn't work?

[Décio Luiz Gazzoni Filho]

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On Jul 19, 2005, at 12:39 AM, Jason Molenda wrote:

> Daniel was correct that this isn't the right forum for Apple gdb  
> questions.  Please send these kinds of things to xcode- 
> users@lists.apple.com.
>
> You'll want to be more specific about your program that isn't  
> working under gdb.  For instance, this works fine with gdb-413:
>
> #include <altivec.h>
> int main () {
>   vector unsigned int x = ((vector unsigned int) vec_splat_u8 (-2));
> }
>
> (gdb) p/x x
> $2 = {0xfefefefe, 0xfefefefe, 0xfefefefe, 0xfefefefe}
> (gdb)
>
> Please follow up on xcode-users@ if you have any questions or  
> problems with the Apple tools.  Thanks!

I asked on the perfoptimization-dev@ list. But sometime between  
posting it and receiving an answer, I figured out the problem (forgot  
to set the clobberlist).

Thanks for the help anyway.

Décio


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