[llvm-commits] [llvm] r58964 - in /llvm/trunk: docs/LangRef.html lib/Bitcode/Reader/BitcodeReader.cpp lib/CodeGen/SelectionDAG/DAGCombiner.cpp lib/CodeGen/SelectionDAG/LegalizeDAG.cpp lib/CodeGen/SelectionDAG/LegalizeTypes.h lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp lib/CodeGen/SelectionDAG/SelectionDAG.cpp lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp lib/Transforms/Scalar/InstructionCombining.cpp lib/VMCore/ConstantFold.cpp lib/VMCore/Instructions.cpp lib/VMCore/Verifier.cpp

[Chris Lattner]

On Nov 9, 2008, at 8:46 PM, Mon P Wang wrote:
> URL: http://llvm.org/viewvc/llvm-project?rev=58964&view=rev
> Log:
> Added support for the following definition of shufflevector
> <result> = shufflevector <n x <ty>> <v1>, <n x <ty>> <v2>, <m x i32>  
> <mask>

Very nice Mon Ping!

One import comment though:

> +++ llvm/trunk/lib/Bitcode/Reader/BitcodeReader.cpp Sun Nov  9  
> 22:46:22 2008
> @@ -1592,16 +1592,12 @@
>           getValue(Record, OpNum, Vec1->getType(), Vec2))
>         return Error("Invalid SHUFFLEVEC record");
>
> -      const Type *MaskTy =
> -        VectorType::get(Type::Int32Ty,
> -                        cast<VectorType>(Vec1->getType())- 
> >getNumElements());
> -
> -      if (getValue(Record, OpNum, MaskTy, Mask))
> +      if (getValueTypePair(Record, OpNum, NextValueNo, Mask))
>         return Error("Invalid SHUFFLEVEC record");
>       I = new ShuffleVectorInst(Vec1, Vec2, Mask);
>       break;
>     }

AFAICT, this will break compatibility with LLVM 2.4 bc files.  This  
isn't good.  It should be possible to check the number of operands in  
Record.  If there are N+1 entries, it is the new format, if there are  
N, it is the old format.  Please verify that you can read 2.4 (or  
earlier) bc files with shuffles in them.

-Chris