On Thu, Aug 16, 2012 at 1:43 PM, Gopalasubramanian, Ganesh
wrote:
>> This won't work, since we have to prefer FMA3 also in case when only "-mfma
>> -mfma4" without -mtune=XX is used.
>> We can add TARGET_FMA_BOTH though, but I doubt there will ever be target
>> that implements both insn sets wit
opalasubramanian, Ganesh; gcc-patches@gcc.gnu.org
Subject: Re: [PATCH,i386] fma,fma4 and xop flags
On Mon, Aug 13, 2012 at 9:50 PM, Richard Henderson wrote:
> On 08/13/2012 12:33 PM, Uros Bizjak wrote:
>> AFAIU fma3 is better than fma4 for bdver2 (the only CPU that
>> implements b
On Mon, Aug 13, 2012 at 9:50 PM, Richard Henderson wrote:
> On 08/13/2012 12:33 PM, Uros Bizjak wrote:
>> AFAIU fma3 is better than fma4 for bdver2 (the only CPU that
>> implements both FMA sets). Current description of bdver2 doesn't even
>> enable fma4 in processor_alias_table due to this fact.
On 08/13/2012 12:33 PM, Uros Bizjak wrote:
> AFAIU fma3 is better than fma4 for bdver2 (the only CPU that
> implements both FMA sets). Current description of bdver2 doesn't even
> enable fma4 in processor_alias_table due to this fact.
>
> The change you are referring to adds preference for fma3 in
On Mon, Aug 13, 2012 at 9:03 PM, Richard Henderson wrote:
>> + (eq_attr "isa" "fma") (symbol_ref "TARGET_FMA")
>> + (eq_attr "isa" "fma4")
>> +(symbol_ref "TARGET_FMA4 && !TARGET_FMA")
>
> Why the !TARGET_FMA for fma4?
>
> If both ISAs are enabled, I don't see why we couldn't ch
On 08/10/2012 03:24 PM, Uros Bizjak wrote:
> + (eq_attr "isa" "fma") (symbol_ref "TARGET_FMA")
> + (eq_attr "isa" "fma4")
> +(symbol_ref "TARGET_FMA4 && !TARGET_FMA")
Why the !TARGET_FMA for fma4?
If both ISAs are enabled, I don't see why we couldn't choose from either.
If they
: [PATCH,i386] fma,fma4 and xop flags
On Fri, Aug 10, 2012 at 10:02 PM, Richard Henderson wrote:
> On 2012-08-10 12:59, Uros Bizjak wrote:
>> Actually, this is the problem you are trying to solve. The fma4
>> patterns are defined before fma3, so gcc prefers these.
>
> The Real
On Fri, Aug 10, 2012 at 10:02 PM, Richard Henderson wrote:
> On 2012-08-10 12:59, Uros Bizjak wrote:
>> Actually, this is the problem you are trying to solve. The fma4
>> patterns are defined before fma3, so gcc prefers these.
>
> The Real Problem is that they should not be separate patterns.
> Th
On Fri, Aug 10, 2012 at 10:22 PM, Richard Henderson wrote:
> On 2012-08-10 13:21, Uros Bizjak wrote:
>> Do you think that enabled isa is also appropriate for 4.7?
>
> I think it's more reliable than relying on pattern ordering.
OK, I will write incremental patch that uses enabled attribute for
ma
On 2012-08-10 13:21, Uros Bizjak wrote:
> Do you think that enabled isa is also appropriate for 4.7?
I think it's more reliable than relying on pattern ordering.
r~
On Fri, Aug 10, 2012 at 10:02 PM, Richard Henderson wrote:
> On 2012-08-10 12:59, Uros Bizjak wrote:
>> Actually, this is the problem you are trying to solve. The fma4
>> patterns are defined before fma3, so gcc prefers these.
>
> The Real Problem is that they should not be separate patterns.
> Th
On 2012-08-10 12:59, Uros Bizjak wrote:
> Actually, this is the problem you are trying to solve. The fma4
> patterns are defined before fma3, so gcc prefers these.
The Real Problem is that they should not be separate patterns.
They should be a single pattern that selects alternatives via
the enabl
On Fri, Aug 10, 2012 at 7:27 AM, Gopalasubramanian, Ganesh
wrote:
>> -mxop implies -mfma4, but reverse is not true.
>
> I think this handling went in for bdver1.
> But, with bdver2, we have both fma and fma4.
> So for bdver2, -mxop should not be enabling one of them.
>
>> if someone set -mfma4 tog
ags.
This will be a one to one mapping and leave the user with lot more liberty.
Please let me know your opinion.
Regards
Ganesh
-Original Message-
From: Uros Bizjak [mailto:ubiz...@gmail.com]
Sent: Friday, August 10, 2012 1:21 AM
To: Gopalasubramanian, Ganesh
Cc: gcc-patches@gcc.gnu.org
S
On Wed, Aug 8, 2012 at 1:31 PM, wrote:
> Bdver2 cpu supports both fma and fma4 instructions.
> Previous to patch, option "-mno-xop" removes "-mfma4".
> Similarly, option "-mno-fma4" removes "-mxop".
It looks to me that there is some misunderstanding. AFAICS:
-mxop implies -mfma4, but reverse i
looks reasonable then. I'll defer to x86 maintainers for
approval though.
Thanks,
Richard.
> Regards
> Ganesh
>
> -Original Message-
> From: Richard Guenther [mailto:richard.guent...@gmail.com]
> Sent: Wednesday, August 08, 2012 5:12 PM
> To: Gopalasubramanian, Gan
w your opinion.
Regards
Ganesh
-Original Message-
From: Richard Guenther [mailto:richard.guent...@gmail.com]
Sent: Wednesday, August 08, 2012 5:12 PM
To: Gopalasubramanian, Ganesh
Cc: gcc-patches@gcc.gnu.org; ubiz...@gmail.com
Subject: Re: [PATCH,i386] fma,fma4 and xop flags
On Wed, Aug 8
On Wed, Aug 8, 2012 at 1:31 PM, wrote:
> Hello,
>
> Bdver2 cpu supports both fma and fma4 instructions.
> Previous to patch, option "-mno-xop" removes "-mfma4".
> Similarly, option "-mno-fma4" removes "-mxop".
Eh? Why's that? I think we should disentangle -mxop and -mfma4
instead. Otherwise,
Hello,
Bdver2 cpu supports both fma and fma4 instructions.
Previous to patch, option "-mno-xop" removes "-mfma4".
Similarly, option "-mno-fma4" removes "-mxop".
So, the patch conditionally disables "-mfma" or "-mfma4".
Enabling "-mxop" is done by also checking "-mfma".
Ok for trunk?
Regards
Gan
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