squiid/llvm
1
0
Fork 0
Code Issues Pull requests Activity

[SelectionDAG] Require constant index for INSERT/EXTRACT_SUBVECTOR.

Browse source 
It sounds like an interesting idea in theory, but nothing is actually
taking advantage of it, and specifying/implementing the edge cases is
painful. So just forbid it.

Differential Revision: https://reviews.llvm.org/D79814
This commit is contained in:
Eli Friedman 2020-05-12 15:09:10 -07:00
parent bd541b217f
commit ed428c429e
2 changed files with 59 additions and 65 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

15
llvm/include/llvm/CodeGen/ISDOpcodes.h
View file

@ -409,16 +409,17 @@ namespace ISD {
CONCAT_VECTORS,
/// INSERT_SUBVECTOR(VECTOR1, VECTOR2, IDX) - Returns a vector
/// with VECTOR2 inserted into VECTOR1 at the (potentially
/// variable) element number IDX, which must be a multiple of the
/// VECTOR2 vector length. The elements of VECTOR1 starting at
/// IDX are overwritten with VECTOR2. Elements IDX through
/// vector_length(VECTOR2) must be valid VECTOR1 indices.
/// with VECTOR2 inserted into VECTOR1 at the constant element number
/// IDX, which must be a multiple of the VECTOR2 vector length. The
/// elements of VECTOR1 starting at IDX are overwritten with VECTOR2.
/// Elements IDX through vector_length(VECTOR2) must be valid VECTOR1
/// indices.
INSERT_SUBVECTOR,
/// EXTRACT_SUBVECTOR(VECTOR, IDX) - Returns a subvector from VECTOR (an
/// vector value) starting with the element number IDX, which must be a
/// constant multiple of the result vector length.
/// vector value) starting with the constant element number IDX, which
/// must be a multiple of the result vector length. Elements IDX through
/// vector_length(VECTOR) must be valid VECTOR indices.
EXTRACT_SUBVECTOR,
/// VECTOR_SHUFFLE(VEC1, VEC2) - Returns a vector, of the same type as

109
llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
View file

@ -5461,44 +5461,40 @@ SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, EVT VT,
}
break;
case ISD::EXTRACT_SUBVECTOR:
if (VT.isSimple() && N1.getValueType().isSimple()) {
assert(VT.isVector() && N1.getValueType().isVector() &&
"Extract subvector VTs must be a vectors!");
assert(VT.getVectorElementType() ==
N1.getValueType().getVectorElementType() &&
"Extract subvector VTs must have the same element type!");
assert(VT.getSimpleVT() <= N1.getSimpleValueType() &&
"Extract subvector must be from larger vector to smaller vector!");
assert(VT.isVector() && N1.getValueType().isVector() &&
"Extract subvector VTs must be a vectors!");
assert(VT.getVectorElementType() ==
N1.getValueType().getVectorElementType() &&
"Extract subvector VTs must have the same element type!");
assert(VT.getVectorNumElements() <=
N1.getValueType().getVectorNumElements() &&
"Extract subvector must be from larger vector to smaller vector!");
assert(N2C && "Extract subvector index must be a constant");
assert(VT.getVectorNumElements() + N2C->getZExtValue() <=
N1.getValueType().getVectorNumElements() &&
"Extract subvector overflow!");
if (N2C) {
assert((VT.getVectorNumElements() + N2C->getZExtValue()
<= N1.getValueType().getVectorNumElements())
&& "Extract subvector overflow!");
}
// Trivial extraction.
if (VT == N1.getValueType())
return N1;
// Trivial extraction.
if (VT.getSimpleVT() == N1.getSimpleValueType())
return N1;
// EXTRACT_SUBVECTOR of an UNDEF is an UNDEF.
if (N1.isUndef())
return getUNDEF(VT);
// EXTRACT_SUBVECTOR of an UNDEF is an UNDEF.
if (N1.isUndef())
return getUNDEF(VT);
// EXTRACT_SUBVECTOR of CONCAT_VECTOR can be simplified if the pieces of
// the concat have the same type as the extract.
if (N2C && N1.getOpcode() == ISD::CONCAT_VECTORS &&
N1.getNumOperands() > 0 &&
VT == N1.getOperand(0).getValueType()) {
unsigned Factor = VT.getVectorNumElements();
return N1.getOperand(N2C->getZExtValue() / Factor);
}
// EXTRACT_SUBVECTOR of INSERT_SUBVECTOR is often created
// during shuffle legalization.
if (N1.getOpcode() == ISD::INSERT_SUBVECTOR && N2 == N1.getOperand(2) &&
VT == N1.getOperand(1).getValueType())
return N1.getOperand(1);
// EXTRACT_SUBVECTOR of CONCAT_VECTOR can be simplified if the pieces of
// the concat have the same type as the extract.
if (N2C && N1.getOpcode() == ISD::CONCAT_VECTORS &&
N1.getNumOperands() > 0 && VT == N1.getOperand(0).getValueType()) {
unsigned Factor = VT.getVectorNumElements();
return N1.getOperand(N2C->getZExtValue() / Factor);
}
// EXTRACT_SUBVECTOR of INSERT_SUBVECTOR is often created
// during shuffle legalization.
if (N1.getOpcode() == ISD::INSERT_SUBVECTOR && N2 == N1.getOperand(2) &&
VT == N1.getOperand(1).getValueType())
return N1.getOperand(1);
break;
}
@ -5670,32 +5666,29 @@ SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, EVT VT,
if (N1.isUndef() && N2.isUndef())
return getUNDEF(VT);
SDValue Index = N3;
if (VT.isSimple() && N1.getValueType().isSimple()
&& N2.getValueType().isSimple()) {
assert(VT.isVector() && N1.getValueType().isVector() &&
N2.getValueType().isVector() &&
"Insert subvector VTs must be a vectors");
assert(VT == N1.getValueType() &&
"Dest and insert subvector source types must match!");
assert(N2.getSimpleValueType() <= N1.getSimpleValueType() &&
"Insert subvector must be from smaller vector to larger vector!");
if (isa<ConstantSDNode>(Index)) {
assert((N2.getValueType().getVectorNumElements() +
cast<ConstantSDNode>(Index)->getZExtValue()
<= VT.getVectorNumElements())
&& "Insert subvector overflow!");
}
assert(VT.isVector() && N1.getValueType().isVector() &&
N2.getValueType().isVector() &&
"Insert subvector VTs must be a vectors");
assert(VT == N1.getValueType() &&
"Dest and insert subvector source types must match!");
assert(N2.getSimpleValueType() <= N1.getSimpleValueType() &&
"Insert subvector must be from smaller vector to larger vector!");
assert(isa<ConstantSDNode>(Index) &&
"Insert subvector index must be constant");
assert(N2.getValueType().getVectorNumElements() +
cast<ConstantSDNode>(Index)->getZExtValue() <=
VT.getVectorNumElements() &&
"Insert subvector overflow!");
// Trivial insertion.
if (VT.getSimpleVT() == N2.getSimpleValueType())
return N2;
// Trivial insertion.
if (VT == N2.getValueType())
return N2;
// If this is an insert of an extracted vector into an undef vector, we
// can just use the input to the extract.
if (N1.isUndef() && N2.getOpcode() == ISD::EXTRACT_SUBVECTOR &&
N2.getOperand(1) == N3 && N2.getOperand(0).getValueType() == VT)
return N2.getOperand(0);
}
// If this is an insert of an extracted vector into an undef vector, we
// can just use the input to the extract.
if (N1.isUndef() && N2.getOpcode() == ISD::EXTRACT_SUBVECTOR &&
N2.getOperand(1) == N3 && N2.getOperand(0).getValueType() == VT)
return N2.getOperand(0);
break;
}
case ISD::BITCAST: