Change the peep for EXTRACT_VECTOR_ELT of BUILD_PAIR to look for

the new CONCAT_VECTORS node type instead, as that's what legalize
uses now. And add a peep for EXTRACT_VECTOR_ELT of INSERT_VECTOR_ELT.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@38503 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dan Gohman 2007-07-10 18:20:44 +00:00
parent e314eb3255
commit 743d3a7548
3 changed files with 37 additions and 7 deletions

View File

@ -1968,19 +1968,31 @@ SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,
case ISD::EXTRACT_VECTOR_ELT:
assert(N2C && "Bad EXTRACT_VECTOR_ELT!");
// EXTRACT_VECTOR_ELT of BUILD_PAIR is often formed while lowering is
// EXTRACT_VECTOR_ELT of CONCAT_VECTORS is often formed while lowering is
// expanding copies of large vectors from registers.
if (N1.getOpcode() == ISD::BUILD_PAIR) {
unsigned NewNumElts = MVT::getVectorNumElements(N1.getValueType()) / 2;
bool Low = N2C->getValue() < NewNumElts;
return getNode(ISD::EXTRACT_VECTOR_ELT, VT, N1.getOperand(!Low),
Low ? N2 : getConstant(N2C->getValue() - NewNumElts,
N2.getValueType()));
if (N1.getOpcode() == ISD::CONCAT_VECTORS &&
N1.getNumOperands() > 0) {
unsigned Factor =
MVT::getVectorNumElements(N1.getOperand(0).getValueType());
return getNode(ISD::EXTRACT_VECTOR_ELT, VT,
N1.getOperand(N2C->getValue() / Factor),
getConstant(N2C->getValue() % Factor, N2.getValueType()));
}
// EXTRACT_VECTOR_ELT of BUILD_VECTOR is often formed while lowering is
// expanding large vector constants.
if (N1.getOpcode() == ISD::BUILD_VECTOR)
return N1.getOperand(N2C->getValue());
// EXTRACT_VECTOR_ELT of INSERT_VECTOR_ELT is often formed when vector
// operations are lowered to scalars.
if (N1.getOpcode() == ISD::INSERT_VECTOR_ELT)
if (ConstantSDNode *IEC = dyn_cast<ConstantSDNode>(N1.getOperand(2))) {
if (IEC == N2C)
return N1.getOperand(1);
else
return getNode(ISD::EXTRACT_VECTOR_ELT, VT, N1.getOperand(0), N2);
}
break;
case ISD::EXTRACT_ELEMENT:
assert(N2C && (unsigned)N2C->getValue() < 2 && "Bad EXTRACT_ELEMENT!");

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@ -0,0 +1,6 @@
; RUN: llvm-as < %s | llc -march=x86-64 | grep {shufps \$3, %xmm0, %xmm0}
define float @foo(<8 x float> %a) {
%c = extractelement <8 x float> %a, i32 3
ret float %c
}

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@ -0,0 +1,12 @@
; RUN: llvm-as < %s | llc -march=x86-64 | grep {pxor %xmm0, %xmm0} | wc -l | grep 2
define float @foo(<4 x float> %a) {
%b = insertelement <4 x float> %a, float 0.0, i32 3
%c = extractelement <4 x float> %b, i32 3
ret float %c
}
define float @bar(float %a) {
%b = insertelement <4 x float> <float 3.4, float 4.5, float 0.0, float 9.2>, float %a, i32 3
%c = extractelement <4 x float> %b, i32 2
ret float %c
}