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| author | Daniel Sanders <daniel.sanders@imgtec.com> | 2014-03-21 16:56:51 +0000 |
|---|---|---|
| committer | Daniel Sanders <daniel.sanders@imgtec.com> | 2014-03-21 16:56:51 +0000 |
| commit | f88a29e66a860db291e5a5888fa1626a4b2ed65f (patch) | |
| tree | 65fdaeff8908b5682374faa3e853ce7a089d396e /llvm/lib | |
| parent | 1014ec3bcb4cb360f171f312b3cf84ecccf2b2e1 (diff) | |
| download | bcm5719-llvm-f88a29e66a860db291e5a5888fa1626a4b2ed65f.tar.gz bcm5719-llvm-f88a29e66a860db291e5a5888fa1626a4b2ed65f.zip | |
[mips] Correct lowering of VECTOR_SHUFFLE to VSHF.
Summary:
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.
The test case that discovered the issue was MultiSource/Benchmarks/nbench.
Reviewers: matheusalmeida
Reviewed By: matheusalmeida
Differential Revision: http://llvm-reviews.chandlerc.com/D3142
llvm-svn: 204480
Diffstat (limited to 'llvm/lib')
| -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 |
