Invalid shufflevector operands! LLVM JavaCPP

Question

I am trying to use LLVMBuildShuffleVector function which asks for:

LLVMBuildShuffleVector (LLVMBuilderRef, LLVMValueRef V1, LLVMValueRef V2, LLVMValueRef Mask, const char *Name)

I have this two LLVMValueRef:

LLVMValueRef value1 = getChildren().get(0).getLlvmValueRef();
LLVMValueRef value2 = getChildren().get(1).getLlvmValueRef();

With them I create mask, which is also a LLVMValueRef, where maskElemArray is an array with the mask's elements:

LLVMValueRef mask = LLVMConstVector(new PointerPointer(maskElemArray), maskElemArray.length);

Now I have to call LLVMBuildShuffleVector:

LLVMValueRef shuffleV = LLVMBuildShuffleVector(builderRef, value1, value2, mask, "shuffleV");

The problem is that I get this error:

Invalid shufflevector operands!
  %shuffleV = shufflevector [8 x i8] %a3, [4 x i8] %b4, <11 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 8, i32 9, i32 10, i32 11>
LLVM ERROR: Broken module found, compilation aborted!

What's the reason of this? What am I missing? Any hints how to solve it? Thanks for all your help!

score 1 · Answer 1 · answered Nov 25 '18 at 06:17

Your value1 and value2 are arrays, but shufflevector only works with vectors.

You'll need to either change the code that creates those arrays to create vectors instead, or you'll need to create vector that contain the arrays' elements (though the latter option does not make much sense as that doesn't have any advantage over just selecting the individual elements yourself and not using shufflevector at all).

Invalid shufflevector operands! LLVM JavaCPP

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