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[x86] Switch the blend implementation to use a MVT switch rather than 

awkward conditions. The readability improvement of this will be even
more important as I generalize it to handle more types.

No functionality changed.

llvm-svn: 218205
This commit is contained in:
Chandler Carruth 2014-09-21 10:36:12 +00:00
parent f098cee2e3
commit 8d0a1b209b
1 changed files with 24 additions and 17 deletions
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41
llvm/lib/Target/X86/X86ISelLowering.cpp
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@ -7234,27 +7234,34 @@ static SDValue lowerVectorShuffleAsBlend(SDLoc DL, MVT VT, SDValue V1,
if (Mask[i] >= 0 && Mask[i] != i)
return SDValue(); // Shuffled V1 input!
}
if (VT == MVT::v4f32 || VT == MVT::v2f64)
switch (VT.SimpleTy) {
case MVT::v2f64:
case MVT::v4f32:
return DAG.getNode(X86ISD::BLENDI, DL, VT, V1, V2,
DAG.getConstant(BlendMask, MVT::i8));
assert(!VT.isFloatingPoint() && "Only v4f32 and v2f64 are supported!");
// For integer shuffles we need to expand the mask and cast the inputs to
// v8i16s prior to blending.
assert((VT == MVT::v8i16 || VT == MVT::v4i32 || VT == MVT::v2i64) &&
"Not a supported integer vector type!");
int Scale = 8 / VT.getVectorNumElements();
BlendMask = 0;
for (int i = 0, Size = Mask.size(); i < Size; ++i)
if (Mask[i] >= Size)
for (int j = 0; j < Scale; ++j)
BlendMask |= 1u << (i * Scale + j);
case MVT::v8i16:
case MVT::v4i32:
case MVT::v2i64: {
// For integer shuffles we need to expand the mask and cast the inputs to
// v8i16s prior to blending.
int Scale = 8 / VT.getVectorNumElements();
BlendMask = 0;
for (int i = 0, Size = Mask.size(); i < Size; ++i)
if (Mask[i] >= Size)
for (int j = 0; j < Scale; ++j)
BlendMask |= 1u << (i * Scale + j);
V1 = DAG.getNode(ISD::BITCAST, DL, MVT::v8i16, V1);
V2 = DAG.getNode(ISD::BITCAST, DL, MVT::v8i16, V2);
return DAG.getNode(ISD::BITCAST, DL, VT,
DAG.getNode(X86ISD::BLENDI, DL, MVT::v8i16, V1, V2,
DAG.getConstant(BlendMask, MVT::i8)));
V1 = DAG.getNode(ISD::BITCAST, DL, MVT::v8i16, V1);
V2 = DAG.getNode(ISD::BITCAST, DL, MVT::v8i16, V2);
return DAG.getNode(ISD::BITCAST, DL, VT,
DAG.getNode(X86ISD::BLENDI, DL, MVT::v8i16, V1, V2,
DAG.getConstant(BlendMask, MVT::i8)));
}
default:
llvm_unreachable("Not a supported integer vector type!");
}
}
/// \brief Try to lower a vector shuffle as a byte rotation.