[RFH] - Less than optimal code compiling 252.eon -O2 for x86

[fjahanian]

On Jun 24, 2005, at 5:20 PM, fjahanian wrote:

>
> On Jun 24, 2005, at 5:06 PM, Steven Bosscher wrote:
>
>
>> On Saturday 25 June 2005 01:48, fjahanian wrote:
>>
>>
>>> On Jun 24, 2005, at 3:16 PM, Andrew Pinski wrote:
>>>
>>>
>>>> I wonder why combine can do the simplification though which is why
>>>> still
>>>> produce good code for the simple testcase:
>>>> void f1(double *d,float *f2)
>>>> {
>>>>   *f2 = 0.0;
>>>>   *d = 0.0;
>>>> }
>>>>
>>>>
>>>
>>> It is hard to reproduce the simple test case, exhibiting the same
>>> problem (-O1 producing better code than -O2). Yes, small test cases
>>> move the desired simplification to other phases.
>>>
>>>
>>
>> It often helps if you know what function your poorer code is in.  You
>> could e.g. try to make the .optimized dump of that function  
>> compilable
>> and see if the problem shows up there again.  Then work your way down
>> to something small.
>>
>
> Yes, I am planning to do this. My first question was though if the  
> RTL generated by -O2, which does not get simplified, is correct and  
> should be optimized in one of the rtl optimizers. If not, then  
> focus shifts to tree optimizers.

This email went through late and superseded by earlier exchanges, It  
turned out to be all RTL related issues.

- faribrz

>
> - Thanks ,fariborz
>
>
>>
>> Gr.
>> Steven
>>
>>
>>
>
>