[cfe-commits] [PATCH] struct{bool} -> int function argument coercion emits an invalid store on ARM

Evgeniy Stepanov eugeni.stepanov at gmail.com
Mon Feb 6 22:17:43 PST 2012


ping

On Sun, Feb 5, 2012 at 8:08 PM, Evgeniy Stepanov
<eugeni.stepanov at gmail.com> wrote:
> Please consider the new patch.
> This time, if the coerce-to type is larger than the real type, we
> reconstruct a value of the coerce-to type in a stack allocation, then
> bitcast & copy it into the destination.
> This is roughly the same logic as in CreateCoercedStore, but with
> multiple sources.
>
> On Sat, Feb 4, 2012 at 6:12 PM, Evgeniy Stepanov
> <eugeni.stepanov at gmail.com> wrote:
>> On Sat, Feb 4, 2012 at 1:07 AM, Eli Friedman <eli.friedman at gmail.com> wrote:
>>> On Fri, Feb 3, 2012 at 4:05 AM, Evgeniy Stepanov
>>> <eugeni.stepanov at gmail.com> wrote:
>>>> Hi,
>>>>
>>>> this is a fix for PR11905.
>>>>
>>>> The current behaviour when generation a function prolog for arguments
>>>> of coerced types is to allocate a stack temp of the real argument type
>>>> and store the argument(s) there. This is wrong, because storage size
>>>> of the coerce-to type can be larger than that of the real type.
>>>>
>>>> The new behaviour is to allocate a temp of the coerced type, copy it,
>>>> and then reference through a bitcasted pointer of the real type.
>>>>
>>>> Please review.
>>>
>>> The real type is sometimes larger than the coerced type... switching
>>> from one to the other only changes which cases are broken issues.
>>
>> Could you give an example of that?
>> In that case, what would you think of allocating the largest of the two types?
>>
>>>
>>> -Eli
-------------- next part --------------
A non-text attachment was scrubbed...
Name: arg.patch
Type: text/x-patch
Size: 3576 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20120207/688c3ab0/attachment.bin>


More information about the cfe-commits mailing list