[llvm-dev] Instruction arguments

[Ehud Katz via llvm-dev]

Constants are created via the `getXXX` routines. They are cached internally
in the LLVMContext, so a particular constant won't be created twice in the
same context ( -> unique). The common idiom for testing a constant is to
compare the pointer itself with the one that you want. Look through the
source code and you will see many examples.

To actually get the value inside the constant you will need to use the API
I described before, which seems like what you are actually looking for.

If all you need is to compare with 1, then there is even a simpler API for
this: Constant::isOneValue().


On Mon, Jan 20, 2020 at 11:23 AM Abid Malik <abidmuslim at gmail.com> wrote:

> Thanks, Ehud.
>
> Thanks, Johannes.
> I am trying to compare the call instruction (openMP ) compatibility wrt
> scheduling, iteration, and chunk size. I think accessing these constant
> values makes sense to form the set of call of instructions which are
> compatible. What do you think?
>
> Can you elaborate?
> "These are SSA values on which pointer equality
> works, especially since constants, e.g., i32 1, are unique."
>
> "i32 1" is constant. But how I can use this constant for equality check?
> It is not a sting or datatype that can be used for binary equality check.
> Thanks,
>
> On Sun, Jan 19, 2020 at 9:02 PM Doerfert, Johannes <jdoerfert at anl.gov>
> wrote:
>
>> On 01/19, Abid Malik via llvm-dev wrote:
>> > How can I convert the arg for binary comparison(== etc.)? If I am
>> correct,
>> > it is not a string. If the argument is "i32 1", Is there a way to access
>> > the content value "1" directly?
>>
>> You don't want to access "1" directly if you want to compare it to
>> something other than a native C++ integer type such as
>> `int/unsigned/long/...`. These are SSA values on which pointer equality
>> works, especially since constants, e.g., i32 1, are unique.
>>
>> Cheers,
>>   Johannes
>>
>
>
> --
> Abid M. Malik
> ******************************************************
> "I have learned silence from the talkative, toleration from the
> intolerant, and kindness from the unkind"---Gibran
> "Success is not for the chosen few, but for the few who choose" --- John
> Maxwell
> "Being a good person does not depend on your religion or status in life,
> your race or skin color, political views or culture. IT DEPENDS ON HOW GOOD
> YOU TREAT OTHERS"--- Abid
> "The Universe is talking to us, and the language of the Universe is
> mathematics."----Abid
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20200120/91a98945/attachment.html>