Patchwork [v3,2/6] target: add symbols for PowerPC cpu features

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Submitter Samuel Martin
Date June 10, 2012, 11:46 a.m.
Message ID <1339328813-6269-5-git-send-email-s.martin49@gmail.com>
Download mbox | patch
Permalink /patch/163987/
State Superseded
Headers show

Comments

Samuel Martin - June 10, 2012, 11:46 a.m.
Signed-off-by: Samuel Martin <s.martin49@gmail.com>
Arnout Vandecappelle - June 12, 2012, 6:15 a.m.
On 06/10/12 13:46, Samuel Martin wrote:
> +# PowerPC cpu features
> +config BR2_POWERPC_CPU_G3
> +	bool
> +config BR2_POWERPC_CPU_G4
> +	bool
> +config BR2_POWERPC_CPU_G5
> +	bool

  I was expecting Altivec here, not the PowerPC CPU generations...  These CPU
features are relevant mostly to allow libraries to select optimized assembly
code, and I don't see much use of G5-specific assembly.  And anyway, the
-mcpu options for a particular CPU are already passed by buildroot.

  Regards,
  Arnout
Gustavo Zacarias - June 12, 2012, 9:48 a.m.
On 2012-06-12 03:15, Arnout Vandecappelle wrote:

> On 06/10/12 13:46, Samuel Martin wrote:
>> +# PowerPC cpu features
>> +config BR2_POWERPC_CPU_G3
>> +	bool
>> +config BR2_POWERPC_CPU_G4
>> +	bool
>> +config BR2_POWERPC_CPU_G5
>> +	bool
>
>  I was expecting Altivec here, not the PowerPC CPU generations...  
> These CPU
> features are relevant mostly to allow libraries to select optimized 
> assembly
> code, and I don't see much use of G5-specific assembly.  And anyway, 
> the
> -mcpu options for a particular CPU are already passed by buildroot.
>
>  Regards,
>  Arnout

Also the G5 is 64-bit capable so one might expect some issues down the 
line since we're not ppc64-capable at the moment.
Regards.
Samuel Martin - June 13, 2012, 10:44 p.m.
Hi Arnout, Gustavoz,

2012/6/12 Gustavo Zacarias <gustavo@zacarias.com.ar>:
> On 2012-06-12 03:15, Arnout Vandecappelle wrote:
>
>> On 06/10/12 13:46, Samuel Martin wrote:
>>>
>>> +# PowerPC cpu features
>>> +config BR2_POWERPC_CPU_G3
>>> +       bool
>>> +config BR2_POWERPC_CPU_G4
>>> +       bool
>>> +config BR2_POWERPC_CPU_G5
>>> +       bool
>>
>>
>>  I was expecting Altivec here, not the PowerPC CPU generations...  These
>> CPU
>> features are relevant mostly to allow libraries to select optimized
>> assembly
>> code, and I don't see much use of G5-specific assembly.  And anyway, the
>> -mcpu options for a particular CPU are already passed by buildroot.
I would expect nothing less ;-)

>>
>>  Regards,
>>  Arnout
>
>
> Also the G5 is 64-bit capable so one might expect some issues down the line
> since we're not ppc64-capable at the moment.
> Regards.
>

So, to sum up and make the relation with the question I asked on the
pacth 6/6 of the serie, you suggest I always turn off the
ENABLE_POWERPC option in the opencv package. That's it?

BTW, I can add an Altivec symbol, and let you (or others) use it in
packages that may take benefit from such optimization.
Let me know...

Regards,

Patch

diff --git a/target/Config.in.arch b/target/Config.in.arch
index 49c01e5..02aa931 100644
--- a/target/Config.in.arch
+++ b/target/Config.in.arch
@@ -600,6 +600,14 @@  config BR2_xtensa_core_name
 	default "dc232b"		if BR2_xtensa_dc232b
 #	default "s5000"			if BR2_xtensa_s5000
 
+# PowerPC cpu features
+config BR2_POWERPC_CPU_G3
+	bool
+config BR2_POWERPC_CPU_G4
+	bool
+config BR2_POWERPC_CPU_G5
+	bool
+
 choice
 	prompt "Target Architecture Variant"
 	depends on BR2_powerpc
@@ -640,12 +648,18 @@  config BR2_powerpc_630
 	bool "630"
 config BR2_powerpc_740
 	bool "740"
+	select BR2_POWERPC_CPU_G3
 config BR2_powerpc_7400
 	bool "7400"
+	select BR2_POWERPC_CPU_G3
+	select BR2_POWERPC_CPU_G4
 config BR2_powerpc_7450
 	bool "7450"
+	select BR2_POWERPC_CPU_G3
+	select BR2_POWERPC_CPU_G4
 config BR2_powerpc_750
 	bool "750"
+	select BR2_POWERPC_CPU_G3
 config BR2_powerpc_801
 	bool "801"
 config BR2_powerpc_821
@@ -656,6 +670,9 @@  config BR2_powerpc_860
 	bool "860"
 config BR2_powerpc_970
 	bool "970"
+	select BR2_POWERPC_CPU_G3
+	select BR2_POWERPC_CPU_G4
+	select BR2_POWERPC_CPU_G5
 config BR2_powerpc_8540
 	bool "8540 / e500v1"
 config BR2_powerpc_8548