gcc-4.5/4.4: Bug in .subreg1 pass?

[Georg-Johann Lay]

Georg-Johann Lay schrieb:
> Denis Chertykov schrieb:
> 
>> 2011/2/26 Georg Johann Lay <avr@gjlay.de>
>>
>>> Eric Botcazou schrieb:
>>>
>>>>> What does "word" mean here? Is it a 32-bit entity or is it 
>>>>> according to
>>>>> word_mode which is QImode for avr?
>>>>
>>>>
>>>> The latter, it is machine-dependent.
>>>>
>>>>
>>>>
>>>>> So the same should be true for QI-subregs of scalar modes if
>>>>> UNITS_PER_WORT = 1. Right?
>>>>
>>>>
>>>> Right.
>>>
>>>
>>> Thanks for that definite clarification.
>>
>>
>>
>> As I understand PR46779 and PR45291 no longer an AVR port bugs.
>> And the following comment is not a true anymore:
>> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45291#c2
>> Am I right ?
> 
> 
> At least the analysis I gave there is incorrect.
> 
> I remember a problem in avr backend concerning the frame pointer because 
> QImode was allowed in FP's hard regs... that sort of problem. Was that 
> fixed here or just in some distribution like WinAVR? So perhaps it's 
> still this FP problem?

Ok, this is the patch I meant:

http://gcc.gnu.org/viewcvs?view=revision&revision=86842

it allows just Pmode in r29:r28 because of some spill failures in 
PR15417 and PR12017.

Johann