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[X86] Remove some unreachable code from LowerBITCAST. 

llvm-svn: 368965
This commit is contained in:
Craig Topper 2019-08-15 05:51:50 +00:00
parent 1542ff5282
commit ba39fcd8c6
1 changed files with 27 additions and 43 deletions
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70
llvm/lib/Target/X86/X86ISelLowering.cpp
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@ -26196,53 +26196,37 @@ static SDValue LowerBITCAST(SDValue Op, const X86Subtarget &Subtarget,
return DAG.getZExtOrTrunc(V, DL, DstVT);
}
if (SrcVT == MVT::v2i32 || SrcVT == MVT::v4i16 || SrcVT == MVT::v8i8 ||
SrcVT == MVT::i64) {
assert(Subtarget.hasSSE2() && "Requires at least SSE2!");
if (DstVT != MVT::f64 && DstVT != MVT::i64 &&
!(DstVT == MVT::x86mmx && SrcVT.isVector()))
// This conversion needs to be expanded.
return SDValue();
assert((SrcVT == MVT::v2i32 || SrcVT == MVT::v4i16 || SrcVT == MVT::v8i8 ||
SrcVT == MVT::i64) && "Unexpected VT!");
SDLoc dl(Op);
if (SrcVT.isVector()) {
// Widen the vector in input in the case of MVT::v2i32.
// Example: from MVT::v2i32 to MVT::v4i32.
MVT NewVT = MVT::getVectorVT(SrcVT.getVectorElementType(),
SrcVT.getVectorNumElements() * 2);
Src = DAG.getNode(ISD::CONCAT_VECTORS, dl, NewVT, Src,
DAG.getUNDEF(SrcVT));
} else {
assert(SrcVT == MVT::i64 && !Subtarget.is64Bit() &&
"Unexpected source type in LowerBITCAST");
Src = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, MVT::v2i64, Src);
}
assert(Subtarget.hasSSE2() && "Requires at least SSE2!");
if (DstVT != MVT::f64 && DstVT != MVT::i64 &&
!(DstVT == MVT::x86mmx && SrcVT.isVector()))
// This conversion needs to be expanded.
return SDValue();
MVT V2X64VT = DstVT == MVT::f64 ? MVT::v2f64 : MVT::v2i64;
Src = DAG.getNode(ISD::BITCAST, dl, V2X64VT, Src);
if (DstVT == MVT::x86mmx)
return DAG.getNode(X86ISD::MOVDQ2Q, dl, DstVT, Src);
return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, DstVT, Src,
DAG.getIntPtrConstant(0, dl));
SDLoc dl(Op);
if (SrcVT.isVector()) {
// Widen the vector in input in the case of MVT::v2i32.
// Example: from MVT::v2i32 to MVT::v4i32.
MVT NewVT = MVT::getVectorVT(SrcVT.getVectorElementType(),
SrcVT.getVectorNumElements() * 2);
Src = DAG.getNode(ISD::CONCAT_VECTORS, dl, NewVT, Src,
DAG.getUNDEF(SrcVT));
} else {
assert(SrcVT == MVT::i64 && !Subtarget.is64Bit() &&
"Unexpected source type in LowerBITCAST");
Src = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, MVT::v2i64, Src);
}
assert(Subtarget.is64Bit() && !Subtarget.hasSSE2() &&
Subtarget.hasMMX() && "Unexpected custom BITCAST");
assert((DstVT == MVT::i64 ||
(DstVT.isVector() && DstVT.getSizeInBits()==64)) &&
"Unexpected custom BITCAST");
// i64 <=> MMX conversions are Legal.
if (SrcVT==MVT::i64 && DstVT.isVector())
return Op;
if (DstVT==MVT::i64 && SrcVT.isVector())
return Op;
// MMX <=> MMX conversions are Legal.
if (SrcVT.isVector() && DstVT.isVector())
return Op;
// All other conversions need to be expanded.
return SDValue();
MVT V2X64VT = DstVT == MVT::f64 ? MVT::v2f64 : MVT::v2i64;
Src = DAG.getNode(ISD::BITCAST, dl, V2X64VT, Src);
if (DstVT == MVT::x86mmx)
return DAG.getNode(X86ISD::MOVDQ2Q, dl, DstVT, Src);
return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, DstVT, Src,
DAG.getIntPtrConstant(0, dl));
}
/// Compute the horizontal sum of bytes in V for the elements of VT.