llvm dev - Oct 2009 - [LLVMdev] Dereference PointerType?

Daniel Waterworth <da.waterworth at googlemail.com> writes:

[snip]

Use the getElementType method of PointerType.
>> size_t size;
>> if (isa<PointerType>(allocated_type)) {
>>   size = sizeof(void*) * 8;
>> } else {
>>   size = allocated_type->getPrimitiveSizeInBits();
>> }
>> // size now equals the size (in bits) of the type allocated
This looks suspicious to me. Maybe you intented

if (isa<PointerType>(allocated_type)) {
  size = sizeof(void*);
} else {
  size = allocated_type->getPrimitiveSizeInBits() * 8;
}

but take a look at getPrimitiveSizeInBits' documentation to make sure
that it is really what you want:

http://llvm.org/doxygen/classllvm_1_1Type.html

-- 
Óscar

Óscar Fuentes wrote:
> Daniel Waterworth <da.waterworth at googlemail.com> writes:
> 
> [snip]
> 
> Use the getElementType method of PointerType.
> 
>>> size_t size;
>>> if (isa<PointerType>(allocated_type)) {
>>>   size = sizeof(void*) * 8;
>>> } else {
>>>   size = allocated_type->getPrimitiveSizeInBits();
>>> }
>>> // size now equals the size (in bits) of the type allocated
> 
> This looks suspicious to me.
Probably he wants getTypeAllocSize (available from target data).  The
special casing of PointerType is both useless and bogus.

Ciao,

Duncan.

It may not be the best way to do what I'm trying to do, but it's not
useless
and bogus. Consider the following:

%1 = alloca i32* ; %1 is of type i32**, dereferenced it becomes a type i32*
and
                         ; the size of that is sizeof(void *) bytes

Having said that I am looking at the target data getTypeAllocSize method.

Daniel

2009/10/20 Duncan Sands <baldrick at free.fr>
> Óscar Fuentes wrote:
>
>> Daniel Waterworth <da.waterworth at googlemail.com> writes:
>>
>> [snip]
>>
>> Use the getElementType method of PointerType.
>>
>>  size_t size;
>>>> if (isa<PointerType>(allocated_type)) {
>>>>  size = sizeof(void*) * 8;
>>>> } else {
>>>>  size = allocated_type->getPrimitiveSizeInBits();
>>>> }
>>>> // size now equals the size (in bits) of the type allocated
>>>>
>>>
>> This looks suspicious to me.
>>
>
> Probably he wants getTypeAllocSize (available from target data).  The
> special casing of PointerType is both useless and bogus.
>
> Ciao,
>
> Duncan.
>
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