mirror of
https://github.com/c64scene-ar/llvm-6502.git
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Enable Nate's excellent DAG combiner work by default. This allows the
removal of a bunch of ad-hoc and crufty code from SelectionDAG.cpp. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23682 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner
parent
7b1fe15de0
commit
af21d55aee
@ -27,11 +27,6 @@
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#include <algorithm>
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using namespace llvm;
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// Temporary boolean for testing the dag combiner
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namespace llvm {
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extern bool CombinerEnabled;
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}
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static bool isCommutativeBinOp(unsigned Opcode) {
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switch (Opcode) {
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case ISD::ADD:
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@ -643,6 +638,20 @@ static bool MaskedValueIsZero(const SDOperand &Op, uint64_t Mask,
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return MaskedValueIsZero(Op.getOperand(0), NewVal, TLI);
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}
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return false;
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case ISD::ADD:
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// (add X, Y) & C == 0 iff (X&C)|(Y&C) == 0 and all bits are low bits.
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if ((Mask&(Mask+1)) == 0) { // All low bits
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if (MaskedValueIsZero(Op.getOperand(0), Mask, TLI) &&
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MaskedValueIsZero(Op.getOperand(1), Mask, TLI)) {
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std::cerr << "MASK: ";
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Op.getOperand(0).Val->dump();
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std::cerr << " - ";
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Op.getOperand(1).Val->dump();
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std::cerr << "\n";
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return true;
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}
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}
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break;
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case ISD::SUB:
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if (ConstantSDNode *CLHS = dyn_cast<ConstantSDNode>(Op.getOperand(0))) {
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// We know that the top bits of C-X are clear if X contains less bits
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@ -876,133 +885,6 @@ SDOperand SelectionDAG::SimplifySetCC(MVT::ValueType VT, SDOperand N1,
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return getSetCC(VT, N2, N1, ISD::getSetCCSwappedOperands(Cond));
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}
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if (!CombinerEnabled) {
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if (N1 == N2) {
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// We can always fold X == Y for integer setcc's.
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if (MVT::isInteger(N1.getValueType()))
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return getConstant(ISD::isTrueWhenEqual(Cond), VT);
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unsigned UOF = ISD::getUnorderedFlavor(Cond);
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if (UOF == 2) // FP operators that are undefined on NaNs.
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return getConstant(ISD::isTrueWhenEqual(Cond), VT);
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if (UOF == unsigned(ISD::isTrueWhenEqual(Cond)))
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return getConstant(UOF, VT);
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// Otherwise, we can't fold it. However, we can simplify it to SETUO/SETO
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// if it is not already.
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ISD::CondCode NewCond = UOF == 0 ? ISD::SETUO : ISD::SETO;
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if (NewCond != Cond)
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return getSetCC(VT, N1, N2, NewCond);
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}
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if (Cond == ISD::SETEQ || Cond == ISD::SETNE) {
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if (N1.getOpcode() == ISD::ADD || N1.getOpcode() == ISD::SUB ||
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N1.getOpcode() == ISD::XOR) {
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// Simplify (X+Y) == (X+Z) --> Y == Z
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if (N1.getOpcode() == N2.getOpcode()) {
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if (N1.getOperand(0) == N2.getOperand(0))
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return getSetCC(VT, N1.getOperand(1), N2.getOperand(1), Cond);
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if (N1.getOperand(1) == N2.getOperand(1))
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return getSetCC(VT, N1.getOperand(0), N2.getOperand(0), Cond);
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if (isCommutativeBinOp(N1.getOpcode())) {
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// If X op Y == Y op X, try other combinations.
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if (N1.getOperand(0) == N2.getOperand(1))
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return getSetCC(VT, N1.getOperand(1), N2.getOperand(0), Cond);
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if (N1.getOperand(1) == N2.getOperand(0))
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return getSetCC(VT, N1.getOperand(1), N2.getOperand(1), Cond);
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}
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}
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// FIXME: move this stuff to the DAG Combiner when it exists!
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// Turn (X^C1) == C2 into X == C1^C2 iff X&~C1 = 0. Common for condcodes.
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if (N1.getOpcode() == ISD::XOR)
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if (ConstantSDNode *XORC = dyn_cast<ConstantSDNode>(N1.getOperand(1)))
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if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(N2)) {
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// If we know that all of the inverted bits are zero, don't bother
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// performing the inversion.
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if (MaskedValueIsZero(N1.getOperand(0), ~XORC->getValue(), TLI))
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return getSetCC(VT, N1.getOperand(0),
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getConstant(XORC->getValue()^RHSC->getValue(),
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N1.getValueType()), Cond);
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}
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// Simplify (X+Z) == X --> Z == 0
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if (N1.getOperand(0) == N2)
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return getSetCC(VT, N1.getOperand(1),
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getConstant(0, N1.getValueType()), Cond);
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if (N1.getOperand(1) == N2) {
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if (isCommutativeBinOp(N1.getOpcode()))
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return getSetCC(VT, N1.getOperand(0),
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getConstant(0, N1.getValueType()), Cond);
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else {
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assert(N1.getOpcode() == ISD::SUB && "Unexpected operation!");
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// (Z-X) == X --> Z == X<<1
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return getSetCC(VT, N1.getOperand(0),
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getNode(ISD::SHL, N2.getValueType(),
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N2, getConstant(1, TLI.getShiftAmountTy())),
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Cond);
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}
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}
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}
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if (N2.getOpcode() == ISD::ADD || N2.getOpcode() == ISD::SUB ||
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N2.getOpcode() == ISD::XOR) {
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// Simplify X == (X+Z) --> Z == 0
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if (N2.getOperand(0) == N1) {
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return getSetCC(VT, N2.getOperand(1),
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getConstant(0, N2.getValueType()), Cond);
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} else if (N2.getOperand(1) == N1) {
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if (isCommutativeBinOp(N2.getOpcode())) {
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return getSetCC(VT, N2.getOperand(0),
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getConstant(0, N2.getValueType()), Cond);
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} else {
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assert(N2.getOpcode() == ISD::SUB && "Unexpected operation!");
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// X == (Z-X) --> X<<1 == Z
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return getSetCC(VT, getNode(ISD::SHL, N2.getValueType(), N1,
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getConstant(1, TLI.getShiftAmountTy())),
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N2.getOperand(0), Cond);
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}
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}
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}
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}
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// Fold away ALL boolean setcc's.
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if (N1.getValueType() == MVT::i1) {
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switch (Cond) {
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default: assert(0 && "Unknown integer setcc!");
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case ISD::SETEQ: // X == Y -> (X^Y)^1
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N1 = getNode(ISD::XOR, MVT::i1,
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getNode(ISD::XOR, MVT::i1, N1, N2),
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getConstant(1, MVT::i1));
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break;
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case ISD::SETNE: // X != Y --> (X^Y)
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N1 = getNode(ISD::XOR, MVT::i1, N1, N2);
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break;
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case ISD::SETGT: // X >s Y --> X == 0 & Y == 1 --> X^1 & Y
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case ISD::SETULT: // X <u Y --> X == 0 & Y == 1 --> X^1 & Y
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N1 = getNode(ISD::AND, MVT::i1, N2,
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getNode(ISD::XOR, MVT::i1, N1, getConstant(1, MVT::i1)));
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break;
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case ISD::SETLT: // X <s Y --> X == 1 & Y == 0 --> Y^1 & X
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case ISD::SETUGT: // X >u Y --> X == 1 & Y == 0 --> Y^1 & X
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N1 = getNode(ISD::AND, MVT::i1, N1,
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getNode(ISD::XOR, MVT::i1, N2, getConstant(1, MVT::i1)));
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break;
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case ISD::SETULE: // X <=u Y --> X == 0 | Y == 1 --> X^1 | Y
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case ISD::SETGE: // X >=s Y --> X == 0 | Y == 1 --> X^1 | Y
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N1 = getNode(ISD::OR, MVT::i1, N2,
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getNode(ISD::XOR, MVT::i1, N1, getConstant(1, MVT::i1)));
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break;
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case ISD::SETUGE: // X >=u Y --> X == 1 | Y == 0 --> Y^1 | X
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case ISD::SETLE: // X <=s Y --> X == 1 | Y == 0 --> Y^1 | X
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N1 = getNode(ISD::OR, MVT::i1, N1,
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getNode(ISD::XOR, MVT::i1, N2, getConstant(1, MVT::i1)));
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break;
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}
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if (VT != MVT::i1)
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N1 = getNode(ISD::ZERO_EXTEND, VT, N1);
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return N1;
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}
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}
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// Could not fold it.
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return SDOperand();
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}
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@ -1337,204 +1219,6 @@ SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,
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std::swap(N1, N2);
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}
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}
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if (!CombinerEnabled) {
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switch (Opcode) {
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default: break;
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case ISD::SHL: // shl 0, X -> 0
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if (N1C->isNullValue()) return N1;
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break;
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case ISD::SRL: // srl 0, X -> 0
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if (N1C->isNullValue()) return N1;
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break;
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case ISD::SRA: // sra -1, X -> -1
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if (N1C->isAllOnesValue()) return N1;
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break;
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case ISD::SIGN_EXTEND_INREG: // SIGN_EXTEND_INREG N1C, EVT
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// Extending a constant? Just return the extended constant.
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SDOperand Tmp = getNode(ISD::TRUNCATE, cast<VTSDNode>(N2)->getVT(), N1);
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return getNode(ISD::SIGN_EXTEND, VT, Tmp);
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}
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}
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}
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if (!CombinerEnabled) {
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if (N2C) {
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uint64_t C2 = N2C->getValue();
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switch (Opcode) {
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case ISD::ADD:
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if (!C2) return N1; // add X, 0 -> X
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break;
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case ISD::SUB:
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if (!C2) return N1; // sub X, 0 -> X
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return getNode(ISD::ADD, VT, N1, getConstant(-C2, VT));
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case ISD::MUL:
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if (!C2) return N2; // mul X, 0 -> 0
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if (N2C->isAllOnesValue()) // mul X, -1 -> 0-X
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return getNode(ISD::SUB, VT, getConstant(0, VT), N1);
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// FIXME: Move this to the DAG combiner when it exists.
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if ((C2 & C2-1) == 0) {
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SDOperand ShAmt = getConstant(Log2_64(C2), TLI.getShiftAmountTy());
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return getNode(ISD::SHL, VT, N1, ShAmt);
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}
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break;
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case ISD::MULHU:
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case ISD::MULHS:
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if (!C2) return N2; // mul X, 0 -> 0
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if (C2 == 1) // 0X*01 -> 0X hi(0X) == 0
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return getConstant(0, VT);
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// Many others could be handled here, including -1, powers of 2, etc.
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break;
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case ISD::UDIV:
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// FIXME: Move this to the DAG combiner when it exists.
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if ((C2 & C2-1) == 0 && C2) {
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SDOperand ShAmt = getConstant(Log2_64(C2), TLI.getShiftAmountTy());
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return getNode(ISD::SRL, VT, N1, ShAmt);
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}
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break;
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case ISD::SHL:
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case ISD::SRL:
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case ISD::SRA:
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// If the shift amount is bigger than the size of the data, then all the
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// bits are shifted out. Simplify to undef.
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if (C2 >= MVT::getSizeInBits(N1.getValueType())) {
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return getNode(ISD::UNDEF, N1.getValueType());
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}
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if (C2 == 0) return N1;
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if (Opcode == ISD::SRA) {
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// If the sign bit is known to be zero, switch this to a SRL.
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if (MaskedValueIsZero(N1,
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1ULL << (MVT::getSizeInBits(N1.getValueType())-1),
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TLI))
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return getNode(ISD::SRL, N1.getValueType(), N1, N2);
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} else {
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// If the part left over is known to be zero, the whole thing is zero.
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uint64_t TypeMask = ~0ULL >> (64-MVT::getSizeInBits(N1.getValueType()));
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if (Opcode == ISD::SRL) {
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if (MaskedValueIsZero(N1, TypeMask << C2, TLI))
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return getConstant(0, N1.getValueType());
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} else if (Opcode == ISD::SHL) {
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if (MaskedValueIsZero(N1, TypeMask >> C2, TLI))
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return getConstant(0, N1.getValueType());
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}
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}
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if (Opcode == ISD::SHL && N1.getNumOperands() == 2)
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if (ConstantSDNode *OpSA = dyn_cast<ConstantSDNode>(N1.getOperand(1))) {
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unsigned OpSAC = OpSA->getValue();
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if (N1.getOpcode() == ISD::SHL) {
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if (C2+OpSAC >= MVT::getSizeInBits(N1.getValueType()))
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return getConstant(0, N1.getValueType());
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return getNode(ISD::SHL, N1.getValueType(), N1.getOperand(0),
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getConstant(C2+OpSAC, N2.getValueType()));
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} else if (N1.getOpcode() == ISD::SRL) {
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// (X >> C1) << C2: if C2 > C1, ((X & ~0<<C1) << C2-C1)
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SDOperand Mask = getNode(ISD::AND, VT, N1.getOperand(0),
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getConstant(~0ULL << OpSAC, VT));
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if (C2 > OpSAC) {
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return getNode(ISD::SHL, VT, Mask,
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getConstant(C2-OpSAC, N2.getValueType()));
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} else {
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// (X >> C1) << C2: if C2 <= C1, ((X & ~0<<C1) >> C1-C2)
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return getNode(ISD::SRL, VT, Mask,
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getConstant(OpSAC-C2, N2.getValueType()));
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}
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} else if (N1.getOpcode() == ISD::SRA) {
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// if C1 == C2, just mask out low bits.
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if (C2 == OpSAC)
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return getNode(ISD::AND, VT, N1.getOperand(0),
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getConstant(~0ULL << C2, VT));
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}
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}
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break;
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case ISD::AND:
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if (!C2) return N2; // X and 0 -> 0
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if (N2C->isAllOnesValue())
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return N1; // X and -1 -> X
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if (MaskedValueIsZero(N1, C2, TLI)) // X and 0 -> 0
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return getConstant(0, VT);
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{
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uint64_t NotC2 = ~C2;
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if (VT != MVT::i64)
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NotC2 &= (1ULL << MVT::getSizeInBits(VT))-1;
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if (MaskedValueIsZero(N1, NotC2, TLI))
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return N1; // if (X & ~C2) -> 0, the and is redundant
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}
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// FIXME: Should add a corresponding version of this for
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// ZERO_EXTEND/SIGN_EXTEND by converting them to an ANY_EXTEND node which
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// we don't have yet.
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// FIXME: NOW WE DO, add this.
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// and (sign_extend_inreg x:16:32), 1 -> and x, 1
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if (N1.getOpcode() == ISD::SIGN_EXTEND_INREG) {
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// If we are masking out the part of our input that was extended, just
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// mask the input to the extension directly.
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unsigned ExtendBits =
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MVT::getSizeInBits(cast<VTSDNode>(N1.getOperand(1))->getVT());
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if ((C2 & (~0ULL << ExtendBits)) == 0)
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return getNode(ISD::AND, VT, N1.getOperand(0), N2);
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} else if (N1.getOpcode() == ISD::OR) {
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if (ConstantSDNode *ORI = dyn_cast<ConstantSDNode>(N1.getOperand(1)))
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if ((ORI->getValue() & C2) == C2) {
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// If the 'or' is setting all of the bits that we are masking for,
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// we know the result of the AND will be the AND mask itself.
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return N2;
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}
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}
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break;
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case ISD::OR:
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if (!C2)return N1; // X or 0 -> X
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if (N2C->isAllOnesValue())
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return N2; // X or -1 -> -1
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break;
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case ISD::XOR:
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if (!C2) return N1; // X xor 0 -> X
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if (N2C->getValue() == 1 && N1.Val->getOpcode() == ISD::SETCC) {
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SDNode *SetCC = N1.Val;
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// !(X op Y) -> (X !op Y)
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bool isInteger = MVT::isInteger(SetCC->getOperand(0).getValueType());
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ISD::CondCode CC = cast<CondCodeSDNode>(SetCC->getOperand(2))->get();
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return getSetCC(SetCC->getValueType(0),
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SetCC->getOperand(0), SetCC->getOperand(1),
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ISD::getSetCCInverse(CC, isInteger));
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} else if (N2C->isAllOnesValue()) {
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if (N1.getOpcode() == ISD::AND || N1.getOpcode() == ISD::OR) {
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SDNode *Op = N1.Val;
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// !(X or Y) -> (!X and !Y) iff X or Y are freely invertible
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// !(X and Y) -> (!X or !Y) iff X or Y are freely invertible
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SDOperand LHS = Op->getOperand(0), RHS = Op->getOperand(1);
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if (isInvertibleForFree(RHS) || isInvertibleForFree(LHS)) {
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LHS = getNode(ISD::XOR, VT, LHS, N2); // RHS = ~LHS
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RHS = getNode(ISD::XOR, VT, RHS, N2); // RHS = ~RHS
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if (Op->getOpcode() == ISD::AND)
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return getNode(ISD::OR, VT, LHS, RHS);
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return getNode(ISD::AND, VT, LHS, RHS);
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}
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}
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// X xor -1 -> not(x) ?
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}
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break;
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}
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// Reassociate ((X op C1) op C2) if possible.
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if (N1.getOpcode() == Opcode && isAssociativeBinOp(Opcode))
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if (ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N1.Val->getOperand(1)))
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return getNode(Opcode, VT, N1.Val->getOperand(0),
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getNode(Opcode, VT, N2, N1.Val->getOperand(1)));
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}
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}
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ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1.Val);
|
||||
@ -1560,180 +1244,16 @@ SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,
|
||||
std::swap(N1, N2);
|
||||
}
|
||||
}
|
||||
|
||||
if (!CombinerEnabled) {
|
||||
if (Opcode == ISD::FP_ROUND_INREG)
|
||||
return getNode(ISD::FP_EXTEND, VT,
|
||||
getNode(ISD::FP_ROUND, cast<VTSDNode>(N2)->getVT(), N1));
|
||||
}
|
||||
}
|
||||
|
||||
// Finally, fold operations that do not require constants.
|
||||
switch (Opcode) {
|
||||
case ISD::TokenFactor:
|
||||
if (!CombinerEnabled) {
|
||||
if (N1.getOpcode() == ISD::EntryToken)
|
||||
return N2;
|
||||
if (N2.getOpcode() == ISD::EntryToken)
|
||||
return N1;
|
||||
}
|
||||
break;
|
||||
case ISD::SDIV: {
|
||||
if (CombinerEnabled) break;
|
||||
|
||||
// If we know the sign bits of both operands are zero, strength reduce to a
|
||||
// udiv instead. Handles (X&15) /s 4 -> X&15 >> 2
|
||||
uint64_t SignBit = 1ULL << (MVT::getSizeInBits(VT)-1);
|
||||
if (MaskedValueIsZero(N2, SignBit, TLI) &&
|
||||
MaskedValueIsZero(N1, SignBit, TLI))
|
||||
return getNode(ISD::UDIV, VT, N1, N2);
|
||||
break;
|
||||
}
|
||||
|
||||
case ISD::AND:
|
||||
case ISD::OR:
|
||||
if (!CombinerEnabled) {
|
||||
if (N1.Val->getOpcode() == ISD::SETCC && N2.Val->getOpcode() == ISD::SETCC){
|
||||
SDNode *LHS = N1.Val, *RHS = N2.Val;
|
||||
SDOperand LL = LHS->getOperand(0), RL = RHS->getOperand(0);
|
||||
SDOperand LR = LHS->getOperand(1), RR = RHS->getOperand(1);
|
||||
ISD::CondCode Op1 = cast<CondCodeSDNode>(LHS->getOperand(2))->get();
|
||||
ISD::CondCode Op2 = cast<CondCodeSDNode>(RHS->getOperand(2))->get();
|
||||
|
||||
if (LR == RR && isa<ConstantSDNode>(LR) &&
|
||||
Op2 == Op1 && MVT::isInteger(LL.getValueType())) {
|
||||
// (X != 0) | (Y != 0) -> (X|Y != 0)
|
||||
// (X == 0) & (Y == 0) -> (X|Y == 0)
|
||||
// (X < 0) | (Y < 0) -> (X|Y < 0)
|
||||
if (cast<ConstantSDNode>(LR)->getValue() == 0 &&
|
||||
((Op2 == ISD::SETEQ && Opcode == ISD::AND) ||
|
||||
(Op2 == ISD::SETNE && Opcode == ISD::OR) ||
|
||||
(Op2 == ISD::SETLT && Opcode == ISD::OR)))
|
||||
return getSetCC(VT, getNode(ISD::OR, LR.getValueType(), LL, RL), LR,
|
||||
Op2);
|
||||
|
||||
if (cast<ConstantSDNode>(LR)->isAllOnesValue()) {
|
||||
// (X == -1) & (Y == -1) -> (X&Y == -1)
|
||||
// (X != -1) | (Y != -1) -> (X&Y != -1)
|
||||
// (X > -1) | (Y > -1) -> (X&Y > -1)
|
||||
if ((Opcode == ISD::AND && Op2 == ISD::SETEQ) ||
|
||||
(Opcode == ISD::OR && Op2 == ISD::SETNE) ||
|
||||
(Opcode == ISD::OR && Op2 == ISD::SETGT))
|
||||
return getSetCC(VT, getNode(ISD::AND, LR.getValueType(), LL, RL),
|
||||
LR, Op2);
|
||||
// (X > -1) & (Y > -1) -> (X|Y > -1)
|
||||
if (Opcode == ISD::AND && Op2 == ISD::SETGT)
|
||||
return getSetCC(VT, getNode(ISD::OR, LR.getValueType(), LL, RL),
|
||||
LR, Op2);
|
||||
}
|
||||
}
|
||||
|
||||
// (X op1 Y) | (Y op2 X) -> (X op1 Y) | (X swapop2 Y)
|
||||
if (LL == RR && LR == RL) {
|
||||
Op2 = ISD::getSetCCSwappedOperands(Op2);
|
||||
goto MatchedBackwards;
|
||||
}
|
||||
|
||||
if (LL == RL && LR == RR) {
|
||||
MatchedBackwards:
|
||||
ISD::CondCode Result;
|
||||
bool isInteger = MVT::isInteger(LL.getValueType());
|
||||
if (Opcode == ISD::OR)
|
||||
Result = ISD::getSetCCOrOperation(Op1, Op2, isInteger);
|
||||
else
|
||||
Result = ISD::getSetCCAndOperation(Op1, Op2, isInteger);
|
||||
|
||||
if (Result != ISD::SETCC_INVALID)
|
||||
return getSetCC(LHS->getValueType(0), LL, LR, Result);
|
||||
}
|
||||
}
|
||||
|
||||
// and/or zext(a), zext(b) -> zext(and/or a, b)
|
||||
if (N1.getOpcode() == ISD::ZERO_EXTEND &&
|
||||
N2.getOpcode() == ISD::ZERO_EXTEND &&
|
||||
N1.getOperand(0).getValueType() == N2.getOperand(0).getValueType())
|
||||
return getNode(ISD::ZERO_EXTEND, VT,
|
||||
getNode(Opcode, N1.getOperand(0).getValueType(),
|
||||
N1.getOperand(0), N2.getOperand(0)));
|
||||
}
|
||||
break;
|
||||
case ISD::XOR:
|
||||
if (!CombinerEnabled) {
|
||||
if (N1 == N2) return getConstant(0, VT); // xor X, Y -> 0
|
||||
}
|
||||
break;
|
||||
case ISD::ADD:
|
||||
if (!CombinerEnabled) {
|
||||
if (N1.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N1.getOperand(0)) &&
|
||||
cast<ConstantSDNode>(N1.getOperand(0))->getValue() == 0)
|
||||
return getNode(ISD::SUB, VT, N2, N1.getOperand(1)); // (0-A)+B -> B-A
|
||||
if (N2.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N2.getOperand(0)) &&
|
||||
cast<ConstantSDNode>(N2.getOperand(0))->getValue() == 0)
|
||||
return getNode(ISD::SUB, VT, N1, N2.getOperand(1)); // A+(0-B) -> A-B
|
||||
if (N2.getOpcode() == ISD::SUB && N1 == N2.Val->getOperand(1))
|
||||
return N2.Val->getOperand(0); // A+(B-A) -> B
|
||||
}
|
||||
break;
|
||||
case ISD::FADD:
|
||||
if (!CombinerEnabled) {
|
||||
if (N2.getOpcode() == ISD::FNEG) // (A+ (-B) -> A-B
|
||||
return getNode(ISD::FSUB, VT, N1, N2.getOperand(0));
|
||||
if (N1.getOpcode() == ISD::FNEG) // ((-A)+B) -> B-A
|
||||
return getNode(ISD::FSUB, VT, N2, N1.getOperand(0));
|
||||
}
|
||||
break;
|
||||
|
||||
case ISD::SUB:
|
||||
if (!CombinerEnabled) {
|
||||
if (N1.getOpcode() == ISD::ADD) {
|
||||
if (N1.Val->getOperand(0) == N2)
|
||||
return N1.Val->getOperand(1); // (A+B)-A == B
|
||||
if (N1.Val->getOperand(1) == N2)
|
||||
return N1.Val->getOperand(0); // (A+B)-B == A
|
||||
}
|
||||
}
|
||||
break;
|
||||
case ISD::FSUB:
|
||||
if (!CombinerEnabled) {
|
||||
if (N2.getOpcode() == ISD::FNEG) // (A- (-B) -> A+B
|
||||
return getNode(ISD::FADD, VT, N1, N2.getOperand(0));
|
||||
}
|
||||
break;
|
||||
case ISD::FP_ROUND_INREG:
|
||||
if (cast<VTSDNode>(N2)->getVT() == VT) return N1; // Not actually rounding.
|
||||
break;
|
||||
case ISD::SIGN_EXTEND_INREG: {
|
||||
MVT::ValueType EVT = cast<VTSDNode>(N2)->getVT();
|
||||
if (EVT == VT) return N1; // Not actually extending
|
||||
if (!CombinerEnabled) {
|
||||
// If we are sign extending an extension, use the original source.
|
||||
if (N1.getOpcode() == ISD::SIGN_EXTEND_INREG ||
|
||||
N1.getOpcode() == ISD::AssertSext)
|
||||
if (cast<VTSDNode>(N1.getOperand(1))->getVT() <= EVT)
|
||||
return N1;
|
||||
|
||||
// If we are sign extending a sextload, return just the load.
|
||||
if (N1.getOpcode() == ISD::SEXTLOAD)
|
||||
if (cast<VTSDNode>(N1.getOperand(3))->getVT() <= EVT)
|
||||
return N1;
|
||||
|
||||
// If we are extending the result of a setcc, and we already know the
|
||||
// contents of the top bits, eliminate the extension.
|
||||
if (N1.getOpcode() == ISD::SETCC &&
|
||||
TLI.getSetCCResultContents() ==
|
||||
TargetLowering::ZeroOrNegativeOneSetCCResult)
|
||||
return N1;
|
||||
|
||||
// If we are sign extending the result of an (and X, C) operation, and we
|
||||
// know the extended bits are zeros already, don't do the extend.
|
||||
if (N1.getOpcode() == ISD::AND)
|
||||
if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getOperand(1))) {
|
||||
uint64_t Mask = N1C->getValue();
|
||||
unsigned NumBits = MVT::getSizeInBits(EVT);
|
||||
if ((Mask & (~0ULL << (NumBits-1))) == 0)
|
||||
return N1;
|
||||
}
|
||||
}
|
||||
break;
|
||||
}
|
||||
|
||||
@ -1840,36 +1360,6 @@ SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,
|
||||
return N3; // select false, X, Y -> Y
|
||||
|
||||
if (N2 == N3) return N2; // select C, X, X -> X
|
||||
|
||||
if (!CombinerEnabled) {
|
||||
if (VT == MVT::i1) { // Boolean SELECT
|
||||
if (N2C) {
|
||||
if (N2C->getValue()) // select C, 1, X -> C | X
|
||||
return getNode(ISD::OR, VT, N1, N3);
|
||||
else // select C, 0, X -> ~C & X
|
||||
return getNode(ISD::AND, VT,
|
||||
getNode(ISD::XOR, N1.getValueType(), N1,
|
||||
getConstant(1, N1.getValueType())), N3);
|
||||
} else if (N3C) {
|
||||
if (N3C->getValue()) // select C, X, 1 -> ~C | X
|
||||
return getNode(ISD::OR, VT,
|
||||
getNode(ISD::XOR, N1.getValueType(), N1,
|
||||
getConstant(1, N1.getValueType())), N2);
|
||||
else // select C, X, 0 -> C & X
|
||||
return getNode(ISD::AND, VT, N1, N2);
|
||||
}
|
||||
|
||||
if (N1 == N2) // X ? X : Y --> X ? 1 : Y --> X | Y
|
||||
return getNode(ISD::OR, VT, N1, N3);
|
||||
if (N1 == N3) // X ? Y : X --> X ? Y : 0 --> X & Y
|
||||
return getNode(ISD::AND, VT, N1, N2);
|
||||
}
|
||||
if (N1.getOpcode() == ISD::SETCC) {
|
||||
SDOperand Simp = SimplifySelectCC(N1.getOperand(0), N1.getOperand(1), N2,
|
||||
N3, cast<CondCodeSDNode>(N1.getOperand(2))->get());
|
||||
if (Simp.Val) return Simp;
|
||||
}
|
||||
}
|
||||
break;
|
||||
case ISD::BRCOND:
|
||||
if (N2C)
|
||||
@ -1999,24 +1489,6 @@ SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,
|
||||
assert(Ops.size() == 5 && "BR_CC takes 5 operands!");
|
||||
assert(Ops[2].getValueType() == Ops[3].getValueType() &&
|
||||
"LHS/RHS of comparison should match types!");
|
||||
|
||||
if (CombinerEnabled) break; // xforms moved to dag combine.
|
||||
|
||||
// Use SimplifySetCC to simplify SETCC's.
|
||||
SDOperand Simp = SimplifySetCC(MVT::i1, Ops[2], Ops[3],
|
||||
cast<CondCodeSDNode>(Ops[1])->get());
|
||||
if (Simp.Val) {
|
||||
if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Simp)) {
|
||||
if (C->getValue() & 1) // Unconditional branch
|
||||
return getNode(ISD::BR, MVT::Other, Ops[0], Ops[4]);
|
||||
else
|
||||
return Ops[0]; // Unconditional Fall through
|
||||
} else if (Simp.Val->getOpcode() == ISD::SETCC) {
|
||||
Ops[2] = Simp.getOperand(0);
|
||||
Ops[3] = Simp.getOperand(1);
|
||||
Ops[1] = Simp.getOperand(2);
|
||||
}
|
||||
}
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
@ -37,18 +37,6 @@
|
||||
#include <iostream>
|
||||
using namespace llvm;
|
||||
|
||||
// Temporary command line code to enable use of the dag combiner as a beta
|
||||
// option.
|
||||
namespace llvm {
|
||||
bool CombinerEnabled;
|
||||
}
|
||||
namespace {
|
||||
cl::opt<bool, true>
|
||||
CombineDAG("enable-dag-combiner", cl::Hidden,
|
||||
cl::desc("Run the DAG combiner before and after Legalize"),
|
||||
cl::location(CombinerEnabled),
|
||||
cl::init(false));
|
||||
}
|
||||
#ifndef NDEBUG
|
||||
static cl::opt<bool>
|
||||
ViewDAGs("view-isel-dags", cl::Hidden,
|
||||
@ -1289,8 +1277,8 @@ void SelectionDAGISel::SelectBasicBlock(BasicBlock *LLVMBB, MachineFunction &MF,
|
||||
// types that are not supported by the target.
|
||||
BuildSelectionDAG(DAG, LLVMBB, PHINodesToUpdate, FuncInfo);
|
||||
|
||||
// Run the DAG combiner in pre-legalize mode, if we are told to do so
|
||||
if (CombinerEnabled) DAG.Combine(false);
|
||||
// Run the DAG combiner in pre-legalize mode.
|
||||
DAG.Combine(false);
|
||||
|
||||
DEBUG(std::cerr << "Lowered selection DAG:\n");
|
||||
DEBUG(DAG.dump());
|
||||
@ -1302,8 +1290,8 @@ void SelectionDAGISel::SelectBasicBlock(BasicBlock *LLVMBB, MachineFunction &MF,
|
||||
DEBUG(std::cerr << "Legalized selection DAG:\n");
|
||||
DEBUG(DAG.dump());
|
||||
|
||||
// Run the DAG combiner in post-legalize mode, if we are told to do so
|
||||
if (CombinerEnabled) DAG.Combine(true);
|
||||
// Run the DAG combiner in post-legalize mode.
|
||||
DAG.Combine(true);
|
||||
|
||||
if (ViewDAGs) DAG.viewGraph();
|
||||
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user