llvm dev - Apr 2015 - [LLVMdev] Is bitcast now needed in LLVM?

Seems like a new change in LLVM has made it so that bitcast of bitcast i8*
%1 to %Foo* meaningless?

If I'm correct is there any need for the bitcast anymore?
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Hi Dave,

You can still bitcast between i32 and float, for example.

Cheers,

James

On Fri, 17 Apr 2015 at 09:03 Dave Pitsbawn <dpitsbawn at gmail.com> wrote:
> Seems like a new change in LLVM has made it so that bitcast of bitcast i8*
> %1 to %Foo* meaningless?
>
> If I'm correct is there any need for the bitcast anymore?
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
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I always thought that bitcast was a no-op internal llvm thing to fit the IR
type system.

I currently use sitofp, but I see your point.

On Fri, Apr 17, 2015 at 1:04 AM, James Molloy <james at jamesmolloy.co.uk>
wrote:
> Hi Dave,
>
> You can still bitcast between i32 and float, for example.
>
> Cheers,
>
> James
>
> On Fri, 17 Apr 2015 at 09:03 Dave Pitsbawn <dpitsbawn at gmail.com>
wrote:
>
>> Seems like a new change in LLVM has made it so that bitcast of bitcast
>> i8* %1 to %Foo* meaningless?
>>
>> If I'm correct is there any need for the bitcast anymore?
>> _______________________________________________
>> LLVM Developers mailing list
>> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>>
>
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On Apr 17, 2015 12:49 AM, "Dave Pitsbawn" <dpitsbawn at
gmail.com> wrote:
>
> Seems like a new change in LLVM has made it so that bitcast of bitcast
i8* %1 to %Foo* meaningless?
>
> If I'm correct is there any need for the bitcast anymore?
What particular observations are you referring to that gave you the
impression that these were not needed?

I'm part-way through migrating LLVM to not depend on the type a pointer
points to, with the intent to eventually remove typed pointers in favor of
a type less pointer type and remove all pointer to pointer bitcasts, but
that work is far from complete.
>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
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