[cfe-commits] [llvm-commits] [PATCH] ARM ABI: handle varargs with vector types.
Eli Friedman
eli.friedman at gmail.com
Mon Oct 15 17:34:40 PDT 2012
On Mon, Oct 15, 2012 at 5:26 PM, Manman Ren <mren at apple.com> wrote:
>
> On Oct 15, 2012, at 5:11 PM, Eli Friedman wrote:
>
>> On Mon, Oct 15, 2012 at 4:46 PM, manman ren <mren at apple.com> wrote:
>>>
>>> The initial patch was updated and separated to two patches (attached).
>>>
>>> The first patch will fix passing legal vector types as varargs:
>>> We make sure the vector is correctly aligned before casting it to the vector type.
>>
>> + uint64_t Size = CGF.getContext().getTypeSize(Ty) / 8;
>> + uint64_t TyAlign = CGF.getContext().getTypeAlign(Ty) / 8;
>> +
>> + // The ABI alignment for vectors is 8 for AAPCS and 4 for APCS.
>> + if (Ty->getAs<VectorType>() && Size >= 8) {
>> + if (getABIKind() == ARMABIInfo::AAPCS_VFP ||
>> + getABIKind() == ARMABIInfo::AAPCS)
>> + TyAlign = 8;
>> + else
>> + TyAlign = 4;
>> + }
>>
>> We should be using the same rules here we do for argument passing. In
>> particular, for APCS, the argument-passing type alignment is
>> unconditionally 4. (This can have effects for structs marked with
>> "__attribute__((aligned(16)))", etc.)
> Is there an interface to query the argument-passing alignment?
Nothing cares about it other than the calling convention code, so
there isn't a general API. It's basically just "match whatever
ARMABIInfo::classifyArgumentType does".
-Eli
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