[llvm-commits] [llvm-gcc-4.2] r46334 - /llvm-gcc-4.2/trunk/gcc/llvm-types.cpp

[Devang Patel]

Hi Duncan,

On Jan 25, 2008, at 1:01 AM, Duncan Sands wrote:

> Hi Devang,
>
>> Fix 2008-01-24-StructAlignAndBitFields.c test case.
>> Bit-field type does not influence struct alignment.
>
> I don't see the point of trying to get the LLVM type to have the same
> alignment as the gcc type.

This patch does not update llvm-gcc to generate LLVM type that matches  
GCC type. GCC type alignment is 2 byte here. Before this patch LLVM  
type alignment was 4 byte and now after this patch struct alignment is  
1 byte.

>  I think all the code that tries to obtain
> equal alignment should just be dropped.  Who cares if the LLVM type  
> has
> a different alignment to the gcc type?  Surely all that matters is  
> that
> when we allocate a variable (alloca or global), if the gcc declaration
> is more aligned than the LLVM type, then we should force the alloca/ 
> global
> to have the gcc alignment.

So idea is for llvm value you "fix" aligment, which can happen N  
number of times for each type instead of fixing type once. However, if  
you can simplify code then that is a good idea. Go for it.

-
Devang