[llvm-commits] Major regressions

[Reid Spencer]

On Sat, 2007-04-21 at 18:28 -0500, Christopher Lamb wrote:
> On Apr 21, 2007, at 6:12 PM, Reid Spencer wrote:
> 
> > On Sat, 2007-04-21 at 18:07 -0500, Christopher Lamb wrote:
> >> I'm getting a regression after my fixes that's coming from
> >> getABIAlignment not finding an alignment to use for a <float x1>  
> >> type,
> >> is this a bug?
> >
> > It could be. <float x 1> isn't a useful vector so it probably doesn't
> > have an ABI Alignment. It should, however, default to whatever the
> > target's alignment is for float. Perhaps that case isn't covered in
> > TargetData or there's something else wrong with TargetData?
> >
> > Did you walk through it in the debugger?
> 
> Yes. It appears that TargetData doesn't have logic to match the case  
> of vector types smaller than the smallest defined ABI vector type.  
> It's asserting in TargetData::getAlignmentInfo:
> 
> assert(BestMatchIdx != -1 && "Didn't find alignment info for this  
> datatype!");

That makes sense.

> 
> I don't think it has enough information to be able to determine  
> whether or not it's being asked for the alignment of a smaller vector  
> type that could be mapped onto a non-vector type.

What is your datalayout specification?

> 
> My feeling is that in this case getAlignmentInfo should return a  
> conservative fallback alignment the same way that's done for integers.

Perhaps, we'll need to discuss with Duncan and Chris though. 

Reid.

> 
> --
> Christopher Lamb
> 
> 
> 
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