On Sat, Dec 26, 2009 at 2:07 AM, Daniel Berlin wrote:
>> In general it will be tricky for latter passes to clean up the messes.
>> The fundamental problem is that the address computation is exposed to
>> PRE prematurely (for a given target ) at GIMPLE level.
>
>
> Yeah, i'm not sure PRE can reall
> In general it will be tricky for latter passes to clean up the messes.
> The fundamental problem is that the address computation is exposed to
> PRE prematurely (for a given target ) at GIMPLE level.
Yeah, i'm not sure PRE can really do anything different here.
I also think you would have a ve
Similar situation happens in non loop context as well. PRE commoned
address computation without knowing the existence of advanced
addressing mode, which result in unnecessary address computation
instruction. The forward substitution code makes local heuristics and
looks at each use individually --
On Wed, Dec 23, 2009 at 10:06 AM, Paolo Bonzini wrote:
> On 12/23/2009 06:47 PM, H.J. Lu wrote:
>>
>> On Wed, Dec 23, 2009 at 8:41 AM, Paolo Bonzini wrote:
>>>
>>> On 12/23/2009 04:19 PM, Bingfeng Mei wrote:
It seems that just commenting out this check in fwprop.c should work.
>>>
>>> Y
On 12/23/2009 06:47 PM, H.J. Lu wrote:
On Wed, Dec 23, 2009 at 8:41 AM, Paolo Bonzini wrote:
On 12/23/2009 04:19 PM, Bingfeng Mei wrote:
It seems that just commenting out this check in fwprop.c should work.
Yes, but it would pessimize x86.
Is there a bug open for x86? Can't we make it ta
On Wed, Dec 23, 2009 at 8:41 AM, Paolo Bonzini wrote:
> On 12/23/2009 04:19 PM, Bingfeng Mei wrote:
>>
>> It seems that just commenting out this check in fwprop.c should work.
>
> Yes, but it would pessimize x86.
>
Is there a bug open for x86? Can't we make it target dependent, something
like
/
On 12/23/2009 04:19 PM, Bingfeng Mei wrote:
It seems that just commenting out this check in fwprop.c should work.
Yes, but it would pessimize x86.
Paolo
On Wed, 2009-12-23 at 16:00 +0100, Paolo Bonzini wrote:
> On 12/23/2009 03:27 PM, Bingfeng Mei wrote:
> > Do you mean if TARGET_ADDRES_COST (non-x86) is defined properly,
> > this should be fixed? Or it requires extra patch?
>
> No, if TARGET_ADDRESS_COST was fixed for x86 (and of course defined
aolo Bonzini [mailto:paolo.bonz...@gmail.com] On
> Behalf Of Paolo Bonzini
> Sent: 23 December 2009 15:01
> To: Bingfeng Mei
> Cc: Steven Bosscher; gcc@gcc.gnu.org; dber...@dberlin.org
> Subject: Re: Unnecessary PRE optimization
>
> On 12/23/2009 03:27 PM, Bingfeng Mei wrote:
> >
On 12/23/2009 03:27 PM, Bingfeng Mei wrote:
Do you mean if TARGET_ADDRES_COST (non-x86) is defined properly,
this should be fixed? Or it requires extra patch?
No, if TARGET_ADDRESS_COST was fixed for x86 (and of course defined
properly for your target), we could fix this very easily.
Paolo
Steven Bosscher
> Cc: Bingfeng Mei; gcc@gcc.gnu.org; dber...@dberlin.org
> Subject: Re: Unnecessary PRE optimization
>
> On 12/23/2009 01:01 PM, Steven Bosscher wrote:
> > On Wed, Dec 23, 2009 at 12:49 PM, Bingfeng
> Mei wrote:
> >> Hello,
> >> I encount
On 12/23/2009 03:05 PM, Joern Rennecke wrote:
So if this is only useful for a limited set of targets, why isn't it
controlled by an option or a target hook so that it is only turned on
on the targets where it is deemed to make sense overall?
Well, this optimization is basically the opposite of
Quoting Paolo Bonzini :
On 12/23/2009 01:01 PM, Steven Bosscher wrote:
On Wed, Dec 23, 2009 at 12:49 PM, Bingfeng Mei wrote:
Hello,
I encounter an issue with PRE optimization, which created worse
Is this at -O2 or -O3?
I think this could be fixed if fwprop propagated addresses into loops;
On 12/23/2009 01:01 PM, Steven Bosscher wrote:
On Wed, Dec 23, 2009 at 12:49 PM, Bingfeng Mei wrote:
Hello,
I encounter an issue with PRE optimization, which created worse
Is this at -O2 or -O3?
I think this could be fixed if fwprop propagated addresses into loops;
it doesn't because it ma
-O2
> -Original Message-
> From: Steven Bosscher [mailto:stevenb@gmail.com]
> Sent: 23 December 2009 12:01
> To: Bingfeng Mei
> Cc: gcc@gcc.gnu.org; dber...@dberlin.org
> Subject: Re: Unnecessary PRE optimization
>
> On Wed, Dec 23, 2009 at 12:49 PM
On Wed, Dec 23, 2009 at 12:49 PM, Bingfeng Mei wrote:
> Hello,
> I encounter an issue with PRE optimization, which created worse
Is this at -O2 or -O3?
Ciao!
Steven
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