[llvm] r174336 - [Stack Alignment] emit warning instead of a hard error

[Eric Christopher]

Also I could be missing it but I couldn't spot the code that checks for the
usage of the bits in not aligning/warning/erroring? Quick pointer?

Thanks!

-eric


On Mon, Feb 4, 2013 at 5:41 PM, Eric Christopher <echristo at gmail.com> wrote:

>
>
>
> On Mon, Feb 4, 2013 at 5:35 PM, Manman Ren <mren at apple.com> wrote:
>
>>
>> Yes, there are related discussions in r169197 and "[PATCH] Stack
>> Alignment: clamp the alignment of stack objects in MachineFrameInfo".
>>
>> But people can use a 32-byte alignment attribute on a machine which only
>> supports 16-byte stack alignment.
>> If the source code further assumes the low bits are zeros, they will get
>> wrong result.
>> But if not, a hard error is too much and it will make existing code which
>> can compile with earlier version failed to build with this patch.
>>
>
> And to use the other side of the argument that won last time :)
>
> But this means that if people aren't looking at the warning or hard
> erroring on warnings then we're going to emit bad code instead of making it
> an error.
>
> -eric
>
>
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