diff options
Diffstat (limited to 'llvm/lib/Target/Mips/MipsSEISelLowering.cpp')
| -rw-r--r-- | llvm/lib/Target/Mips/MipsSEISelLowering.cpp | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/llvm/lib/Target/Mips/MipsSEISelLowering.cpp b/llvm/lib/Target/Mips/MipsSEISelLowering.cpp index c40426d0e20..2fe5714e841 100644 --- a/llvm/lib/Target/Mips/MipsSEISelLowering.cpp +++ b/llvm/lib/Target/Mips/MipsSEISelLowering.cpp @@ -2566,7 +2566,14 @@ static SDValue lowerVECTOR_SHUFFLE_VSHF(SDValue Op, EVT ResTy, else llvm_unreachable("shuffle vector mask references neither vector operand?"); - return DAG.getNode(MipsISD::VSHF, DL, ResTy, MaskVec, Op0, Op1); + // VECTOR_SHUFFLE concatenates the vectors in an vectorwise fashion. + // <0b00, 0b01> + <0b10, 0b11> -> <0b00, 0b01, 0b10, 0b11> + // VSHF concatenates the vectors in a bitwise fashion: + // <0b00, 0b01> + <0b10, 0b11> -> + // 0b0100 + 0b1110 -> 0b01001110 + // <0b10, 0b11, 0b00, 0b01> + // We must therefore swap the operands to get the correct result. + return DAG.getNode(MipsISD::VSHF, DL, ResTy, MaskVec, Op1, Op0); } // Lower VECTOR_SHUFFLE into one of a number of instructions depending on the |
