llvm dev - Apr 2015 - [LLVMdev] How to do bitcast for double to <2 x double>

How can I write code to generate IR for:
%2 = bitcast double* %1 to <2 x double>*.
%3 = load <2 x double>* %2, align 16
Basically, it is similar to x86 _mm_load_pd1 intrinsics.

Thanks,
Zhi
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Create a type that is a "vector (array) of 2 double", and then a
pointer to that. Now use bitcast your on double pointer to that
pointer type you've created, and then create a load...

If you need more help, it would help if you post the code you are working on...

--
Mats

On 15 April 2015 at 19:51, zhi chen <zchenhn at gmail.com>
wrote:
> How can I write code to generate IR for:
> %2 = bitcast double* %1 to <2 x double>*.
> %3 = load <2 x double>* %2, align 16
> Basically, it is similar to x86 _mm_load_pd1 intrinsics.
>
> Thanks,
> Zhi
>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>

What I want to do is to change the pInst from : 2%= load double* %1, align
8 to 2% = load < 2 x double>* %1, align 16, where <2 x double>
should be
two double identical double values that is same as the one in the previous
instruction

Instruction* ScalarToVectorLoad(Instruction* pInst) {
  Value *loadValue = pInst->getOperand(0);
  Instruction *newLoad;   //this one should be 2% = load < 2 x double>* %1

  BitCastInst *scalarToVector = new BitCastInst(loadValue,
VectorType::get(Type::getDoubleTy(currF->getContext()), 2),
"vectorizedLoad", pInst);
  newLoad = new LoadInst(); //to be implemented...
  return newLoad;
}

On Wed, Apr 15, 2015 at 1:03 PM, mats petersson <mats at
planetcatfish.com>
wrote:
> Create a type that is a "vector (array) of 2 double", and then a
> pointer to that. Now use bitcast your on double pointer to that
> pointer type you've created, and then create a load...
>
> If you need more help, it would help if you post the code you are working
> on...
>
> --
> Mats
>
> On 15 April 2015 at 19:51, zhi chen <zchenhn at gmail.com> wrote:
> > How can I write code to generate IR for:
> > %2 = bitcast double* %1 to <2 x double>*.
> > %3 = load <2 x double>* %2, align 16
> > Basically, it is similar to x86 _mm_load_pd1 intrinsics.
> >
> > Thanks,
> > Zhi
> >
> > _______________________________________________
> > 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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