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-rw-r--r--lib/CodeGen/SelectionDAG/SelectionDAG.cpp171
1 files changed, 17 insertions, 154 deletions
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 00293814b0..5a0f5b1e99 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -736,8 +736,8 @@ SDOperand SelectionDAG::getSrcValue(const Value *V, int Offset) {
return SDOperand(N, 0);
}
-SDOperand SelectionDAG::SimplifySetCC(MVT::ValueType VT, SDOperand N1,
- SDOperand N2, ISD::CondCode Cond) {
+SDOperand SelectionDAG::FoldSetCC(MVT::ValueType VT, SDOperand N1,
+ SDOperand N2, ISD::CondCode Cond) {
// These setcc operations always fold.
switch (Cond) {
default: break;
@@ -759,18 +759,18 @@ SDOperand SelectionDAG::SimplifySetCC(MVT::ValueType VT, SDOperand N1,
assert(!MVT::isInteger(N1.getValueType()) && "Illegal setcc for integer!");
break;
}
-
+
if (ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.Val)) {
uint64_t C2 = N2C->getValue();
if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val)) {
uint64_t C1 = N1C->getValue();
-
+
// Sign extend the operands if required
if (ISD::isSignedIntSetCC(Cond)) {
C1 = N1C->getSignExtended();
C2 = N2C->getSignExtended();
}
-
+
switch (Cond) {
default: assert(0 && "Unknown integer setcc!");
case ISD::SETEQ: return getConstant(C1 == C2, VT);
@@ -784,156 +784,12 @@ SDOperand SelectionDAG::SimplifySetCC(MVT::ValueType VT, SDOperand N1,
case ISD::SETLE: return getConstant((int64_t)C1 <= (int64_t)C2, VT);
case ISD::SETGE: return getConstant((int64_t)C1 >= (int64_t)C2, VT);
}
- } else {
- // If the LHS is a ZERO_EXTEND, perform the comparison on the input.
- if (N1.getOpcode() == ISD::ZERO_EXTEND) {
- unsigned InSize = MVT::getSizeInBits(N1.getOperand(0).getValueType());
-
- // If the comparison constant has bits in the upper part, the
- // zero-extended value could never match.
- if (C2 & (~0ULL << InSize)) {
- unsigned VSize = MVT::getSizeInBits(N1.getValueType());
- switch (Cond) {
- case ISD::SETUGT:
- case ISD::SETUGE:
- case ISD::SETEQ: return getConstant(0, VT);
- case ISD::SETULT:
- case ISD::SETULE:
- case ISD::SETNE: return getConstant(1, VT);
- case ISD::SETGT:
- case ISD::SETGE:
- // True if the sign bit of C2 is set.
- return getConstant((C2 & (1ULL << VSize)) != 0, VT);
- case ISD::SETLT:
- case ISD::SETLE:
- // True if the sign bit of C2 isn't set.
- return getConstant((C2 & (1ULL << VSize)) == 0, VT);
- default:
- break;
- }
- }
-
- // Otherwise, we can perform the comparison with the low bits.
- switch (Cond) {
- case ISD::SETEQ:
- case ISD::SETNE:
- case ISD::SETUGT:
- case ISD::SETUGE:
- case ISD::SETULT:
- case ISD::SETULE:
- return getSetCC(VT, N1.getOperand(0),
- getConstant(C2, N1.getOperand(0).getValueType()),
- Cond);
- default:
- break; // todo, be more careful with signed comparisons
- }
- } else if (N1.getOpcode() == ISD::SIGN_EXTEND_INREG &&
- (Cond == ISD::SETEQ || Cond == ISD::SETNE)) {
- MVT::ValueType ExtSrcTy = cast<VTSDNode>(N1.getOperand(1))->getVT();
- unsigned ExtSrcTyBits = MVT::getSizeInBits(ExtSrcTy);
- MVT::ValueType ExtDstTy = N1.getValueType();
- unsigned ExtDstTyBits = MVT::getSizeInBits(ExtDstTy);
-
- // If the extended part has any inconsistent bits, it cannot ever
- // compare equal. In other words, they have to be all ones or all
- // zeros.
- uint64_t ExtBits =
- (~0ULL >> (64-ExtSrcTyBits)) & (~0ULL << (ExtDstTyBits-1));
- if ((C2 & ExtBits) != 0 && (C2 & ExtBits) != ExtBits)
- return getConstant(Cond == ISD::SETNE, VT);
-
- // Otherwise, make this a use of a zext.
- return getSetCC(VT, getZeroExtendInReg(N1.getOperand(0), ExtSrcTy),
- getConstant(C2 & (~0ULL>>(64-ExtSrcTyBits)), ExtDstTy),
- Cond);
- }
-
- uint64_t MinVal, MaxVal;
- unsigned OperandBitSize = MVT::getSizeInBits(N2C->getValueType(0));
- if (ISD::isSignedIntSetCC(Cond)) {
- MinVal = 1ULL << (OperandBitSize-1);
- if (OperandBitSize != 1) // Avoid X >> 64, which is undefined.
- MaxVal = ~0ULL >> (65-OperandBitSize);
- else
- MaxVal = 0;
- } else {
- MinVal = 0;
- MaxVal = ~0ULL >> (64-OperandBitSize);
- }
-
- // Canonicalize GE/LE comparisons to use GT/LT comparisons.
- if (Cond == ISD::SETGE || Cond == ISD::SETUGE) {
- if (C2 == MinVal) return getConstant(1, VT); // X >= MIN --> true
- --C2; // X >= C1 --> X > (C1-1)
- return getSetCC(VT, N1, getConstant(C2, N2.getValueType()),
- (Cond == ISD::SETGE) ? ISD::SETGT : ISD::SETUGT);
- }
-
- if (Cond == ISD::SETLE || Cond == ISD::SETULE) {
- if (C2 == MaxVal) return getConstant(1, VT); // X <= MAX --> true
- ++C2; // X <= C1 --> X < (C1+1)
- return getSetCC(VT, N1, getConstant(C2, N2.getValueType()),
- (Cond == ISD::SETLE) ? ISD::SETLT : ISD::SETULT);
- }
-
- if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C2 == MinVal)
- return getConstant(0, VT); // X < MIN --> false
-
- // Canonicalize setgt X, Min --> setne X, Min
- if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C2 == MinVal)
- return getSetCC(VT, N1, N2, ISD::SETNE);
-
- // If we have setult X, 1, turn it into seteq X, 0
- if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C2 == MinVal+1)
- return getSetCC(VT, N1, getConstant(MinVal, N1.getValueType()),
- ISD::SETEQ);
- // If we have setugt X, Max-1, turn it into seteq X, Max
- else if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C2 == MaxVal-1)
- return getSetCC(VT, N1, getConstant(MaxVal, N1.getValueType()),
- ISD::SETEQ);
-
- // If we have "setcc X, C1", check to see if we can shrink the immediate
- // by changing cc.
-
- // SETUGT X, SINTMAX -> SETLT X, 0
- if (Cond == ISD::SETUGT && OperandBitSize != 1 &&
- C2 == (~0ULL >> (65-OperandBitSize)))
- return getSetCC(VT, N1, getConstant(0, N2.getValueType()), ISD::SETLT);
-
- // FIXME: Implement the rest of these.
-
-
- // Fold bit comparisons when we can.
- if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
- VT == N1.getValueType() && N1.getOpcode() == ISD::AND)
- if (ConstantSDNode *AndRHS =
- dyn_cast<ConstantSDNode>(N1.getOperand(1))) {
- if (Cond == ISD::SETNE && C2 == 0) {// (X & 8) != 0 --> (X & 8) >> 3
- // Perform the xform if the AND RHS is a single bit.
- if (isPowerOf2_64(AndRHS->getValue())) {
- return getNode(ISD::SRL, VT, N1,
- getConstant(Log2_64(AndRHS->getValue()),
- TLI.getShiftAmountTy()));
- }
- } else if (Cond == ISD::SETEQ && C2 == AndRHS->getValue()) {
- // (X & 8) == 8 --> (X & 8) >> 3
- // Perform the xform if C2 is a single bit.
- if (isPowerOf2_64(C2)) {
- return getNode(ISD::SRL, VT, N1,
- getConstant(Log2_64(C2),TLI.getShiftAmountTy()));
- }
- }
- }
}
- } else if (isa<ConstantSDNode>(N1.Val)) {
- // Ensure that the constant occurs on the RHS.
- return getSetCC(VT, N2, N1, ISD::getSetCCSwappedOperands(Cond));
}
-
if (ConstantFPSDNode *N1C = dyn_cast<ConstantFPSDNode>(N1.Val))
if (ConstantFPSDNode *N2C = dyn_cast<ConstantFPSDNode>(N2.Val)) {
double C1 = N1C->getValue(), C2 = N2C->getValue();
-
+
switch (Cond) {
default: break; // FIXME: Implement the rest of these!
case ISD::SETEQ: return getConstant(C1 == C2, VT);
@@ -947,11 +803,12 @@ SDOperand SelectionDAG::SimplifySetCC(MVT::ValueType VT, SDOperand N1,
// Ensure that the constant occurs on the RHS.
return getSetCC(VT, N2, N1, ISD::getSetCCSwappedOperands(Cond));
}
-
+
// Could not fold it.
return SDOperand();
}
+
/// getNode - Gets or creates the specified node.
///
SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT) {
@@ -1369,8 +1226,14 @@ SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,
}
}
- // Finally, fold operations that do not require constants.
+ // Fold operations.
switch (Opcode) {
+ case ISD::AND:
+ // (X & 0) -> 0. This commonly occurs when legalizing i64 values, so it's
+ // worth handling here.
+ if (N2C && N2C->getValue() == 0)
+ return N2;
+ break;
case ISD::FP_ROUND_INREG:
if (cast<VTSDNode>(N2)->getVT() == VT) return N1; // Not actually rounding.
break;
@@ -1445,8 +1308,8 @@ SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,
//ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N3.Val);
switch (Opcode) {
case ISD::SETCC: {
- // Use SimplifySetCC to simplify SETCC's.
- SDOperand Simp = SimplifySetCC(VT, N1, N2, cast<CondCodeSDNode>(N3)->get());
+ // Use FoldSetCC to simplify SETCC's.
+ SDOperand Simp = FoldSetCC(VT, N1, N2, cast<CondCodeSDNode>(N3)->get());
if (Simp.Val) return Simp;
break;
}
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2025-05-12 22:06:37 +0000