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path: root/lib/CodeGen/SelectionDAG/TargetLowering.cpp
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-rw-r--r--lib/CodeGen/SelectionDAG/TargetLowering.cpp111
1 files changed, 55 insertions, 56 deletions
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 792de75..e341e15 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -39,28 +39,6 @@ static cl::opt<bool>
AllowPromoteIntElem("promote-elements", cl::Hidden, cl::init(true),
cl::desc("Allow promotion of integer vector element types"));
-namespace llvm {
-TLSModel::Model getTLSModel(const GlobalValue *GV, Reloc::Model reloc) {
- bool isLocal = GV->hasLocalLinkage();
- bool isDeclaration = GV->isDeclaration();
- // FIXME: what should we do for protected and internal visibility?
- // For variables, is internal different from hidden?
- bool isHidden = GV->hasHiddenVisibility();
-
- if (reloc == Reloc::PIC_) {
- if (isLocal || isHidden)
- return TLSModel::LocalDynamic;
- else
- return TLSModel::GeneralDynamic;
- } else {
- if (!isDeclaration || isHidden)
- return TLSModel::LocalExec;
- else
- return TLSModel::InitialExec;
- }
-}
-}
-
/// InitLibcallNames - Set default libcall names.
///
static void InitLibcallNames(const char **Names) {
@@ -1101,8 +1079,12 @@ unsigned TargetLowering::getJumpTableEncoding() const {
SDValue TargetLowering::getPICJumpTableRelocBase(SDValue Table,
SelectionDAG &DAG) const {
// If our PIC model is GP relative, use the global offset table as the base.
- if (getJumpTableEncoding() == MachineJumpTableInfo::EK_GPRel32BlockAddress)
+ unsigned JTEncoding = getJumpTableEncoding();
+
+ if ((JTEncoding == MachineJumpTableInfo::EK_GPRel64BlockAddress) ||
+ (JTEncoding == MachineJumpTableInfo::EK_GPRel32BlockAddress))
return DAG.getGLOBAL_OFFSET_TABLE(getPointerTy());
+
return Table;
}
@@ -1244,7 +1226,7 @@ bool TargetLowering::SimplifyDemandedBits(SDValue Op,
if (Depth != 0) {
// If not at the root, Just compute the KnownZero/KnownOne bits to
// simplify things downstream.
- TLO.DAG.ComputeMaskedBits(Op, DemandedMask, KnownZero, KnownOne, Depth);
+ TLO.DAG.ComputeMaskedBits(Op, KnownZero, KnownOne, Depth);
return false;
}
// If this is the root being simplified, allow it to have multiple uses,
@@ -1263,8 +1245,8 @@ bool TargetLowering::SimplifyDemandedBits(SDValue Op,
switch (Op.getOpcode()) {
case ISD::Constant:
// We know all of the bits for a constant!
- KnownOne = cast<ConstantSDNode>(Op)->getAPIntValue() & NewMask;
- KnownZero = ~KnownOne & NewMask;
+ KnownOne = cast<ConstantSDNode>(Op)->getAPIntValue();
+ KnownZero = ~KnownOne;
return false; // Don't fall through, will infinitely loop.
case ISD::AND:
// If the RHS is a constant, check to see if the LHS would be zero without
@@ -1274,8 +1256,7 @@ bool TargetLowering::SimplifyDemandedBits(SDValue Op,
if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
APInt LHSZero, LHSOne;
// Do not increment Depth here; that can cause an infinite loop.
- TLO.DAG.ComputeMaskedBits(Op.getOperand(0), NewMask,
- LHSZero, LHSOne, Depth);
+ TLO.DAG.ComputeMaskedBits(Op.getOperand(0), LHSZero, LHSOne, Depth);
// If the LHS already has zeros where RHSC does, this and is dead.
if ((LHSZero & NewMask) == (~RHSC->getAPIntValue() & NewMask))
return TLO.CombineTo(Op, Op.getOperand(0));
@@ -1386,8 +1367,9 @@ bool TargetLowering::SimplifyDemandedBits(SDValue Op,
// bits on that side are also known to be set on the other side, turn this
// into an AND, as we know the bits will be cleared.
// e.g. (X | C1) ^ C2 --> (X | C1) & ~C2 iff (C1&C2) == C2
- if ((NewMask & (KnownZero|KnownOne)) == NewMask) { // all known
- if ((KnownOne & KnownOne2) == KnownOne) {
+ // NB: it is okay if more bits are known than are requested
+ if ((NewMask & (KnownZero|KnownOne)) == NewMask) { // all known on one side
+ if (KnownOne == KnownOne2) { // set bits are the same on both sides
EVT VT = Op.getValueType();
SDValue ANDC = TLO.DAG.getConstant(~KnownOne & NewMask, VT);
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::AND, dl, VT,
@@ -1725,11 +1707,11 @@ bool TargetLowering::SimplifyDemandedBits(SDValue Op,
// If the sign bit is known one, the top bits match.
if (KnownOne.intersects(InSignBit)) {
- KnownOne |= NewBits;
- KnownZero &= ~NewBits;
+ KnownOne |= NewBits;
+ assert((KnownZero & NewBits) == 0);
} else { // Otherwise, top bits aren't known.
- KnownOne &= ~NewBits;
- KnownZero &= ~NewBits;
+ assert((KnownOne & NewBits) == 0);
+ assert((KnownZero & NewBits) == 0);
}
break;
}
@@ -1863,7 +1845,7 @@ bool TargetLowering::SimplifyDemandedBits(SDValue Op,
// FALL THROUGH
default:
// Just use ComputeMaskedBits to compute output bits.
- TLO.DAG.ComputeMaskedBits(Op, NewMask, KnownZero, KnownOne, Depth);
+ TLO.DAG.ComputeMaskedBits(Op, KnownZero, KnownOne, Depth);
break;
}
@@ -1879,7 +1861,6 @@ bool TargetLowering::SimplifyDemandedBits(SDValue Op,
/// in Mask are known to be either zero or one and return them in the
/// KnownZero/KnownOne bitsets.
void TargetLowering::computeMaskedBitsForTargetNode(const SDValue Op,
- const APInt &Mask,
APInt &KnownZero,
APInt &KnownOne,
const SelectionDAG &DAG,
@@ -1890,7 +1871,7 @@ void TargetLowering::computeMaskedBitsForTargetNode(const SDValue Op,
Op.getOpcode() == ISD::INTRINSIC_VOID) &&
"Should use MaskedValueIsZero if you don't know whether Op"
" is a target node!");
- KnownZero = KnownOne = APInt(Mask.getBitWidth(), 0);
+ KnownZero = KnownOne = APInt(KnownOne.getBitWidth(), 0);
}
/// ComputeNumSignBitsForTargetNode - This method can be implemented by
@@ -1934,9 +1915,8 @@ static bool ValueHasExactlyOneBitSet(SDValue Val, const SelectionDAG &DAG) {
// Fall back to ComputeMaskedBits to catch other known cases.
EVT OpVT = Val.getValueType();
unsigned BitWidth = OpVT.getScalarType().getSizeInBits();
- APInt Mask = APInt::getAllOnesValue(BitWidth);
APInt KnownZero, KnownOne;
- DAG.ComputeMaskedBits(Val, Mask, KnownZero, KnownOne);
+ DAG.ComputeMaskedBits(Val, KnownZero, KnownOne);
return (KnownZero.countPopulation() == BitWidth - 1) &&
(KnownOne.countPopulation() == 1);
}
@@ -2432,8 +2412,15 @@ TargetLowering::SimplifySetCC(EVT VT, SDValue N0, SDValue N1,
if (N0 == N1) {
// We can always fold X == X for integer setcc's.
- if (N0.getValueType().isInteger())
- return DAG.getConstant(ISD::isTrueWhenEqual(Cond), VT);
+ if (N0.getValueType().isInteger()) {
+ switch (getBooleanContents(N0.getValueType().isVector())) {
+ case UndefinedBooleanContent:
+ case ZeroOrOneBooleanContent:
+ return DAG.getConstant(ISD::isTrueWhenEqual(Cond), VT);
+ case ZeroOrNegativeOneBooleanContent:
+ return DAG.getConstant(ISD::isTrueWhenEqual(Cond) ? -1 : 0, VT);
+ }
+ }
unsigned UOF = ISD::getUnorderedFlavor(Cond);
if (UOF == 2) // FP operators that are undefined on NaNs.
return DAG.getConstant(ISD::isTrueWhenEqual(Cond), VT);
@@ -2467,6 +2454,10 @@ TargetLowering::SimplifySetCC(EVT VT, SDValue N0, SDValue N1,
}
}
+ // If RHS is a legal immediate value for a compare instruction, we need
+ // to be careful about increasing register pressure needlessly.
+ bool LegalRHSImm = false;
+
if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(N1)) {
if (ConstantSDNode *LHSR = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
// Turn (X+C1) == C2 --> X == C2-C1
@@ -2501,25 +2492,33 @@ TargetLowering::SimplifySetCC(EVT VT, SDValue N0, SDValue N1,
Cond);
}
}
+
+ // Could RHSC fold directly into a compare?
+ if (RHSC->getValueType(0).getSizeInBits() <= 64)
+ LegalRHSImm = isLegalICmpImmediate(RHSC->getSExtValue());
}
// Simplify (X+Z) == X --> Z == 0
- if (N0.getOperand(0) == N1)
- return DAG.getSetCC(dl, VT, N0.getOperand(1),
- DAG.getConstant(0, N0.getValueType()), Cond);
- if (N0.getOperand(1) == N1) {
- if (DAG.isCommutativeBinOp(N0.getOpcode()))
- return DAG.getSetCC(dl, VT, N0.getOperand(0),
- DAG.getConstant(0, N0.getValueType()), Cond);
- else if (N0.getNode()->hasOneUse()) {
- assert(N0.getOpcode() == ISD::SUB && "Unexpected operation!");
- // (Z-X) == X --> Z == X<<1
- SDValue SH = DAG.getNode(ISD::SHL, dl, N1.getValueType(),
- N1,
+ // Don't do this if X is an immediate that can fold into a cmp
+ // instruction and X+Z has other uses. It could be an induction variable
+ // chain, and the transform would increase register pressure.
+ if (!LegalRHSImm || N0.getNode()->hasOneUse()) {
+ if (N0.getOperand(0) == N1)
+ return DAG.getSetCC(dl, VT, N0.getOperand(1),
+ DAG.getConstant(0, N0.getValueType()), Cond);
+ if (N0.getOperand(1) == N1) {
+ if (DAG.isCommutativeBinOp(N0.getOpcode()))
+ return DAG.getSetCC(dl, VT, N0.getOperand(0),
+ DAG.getConstant(0, N0.getValueType()), Cond);
+ else if (N0.getNode()->hasOneUse()) {
+ assert(N0.getOpcode() == ISD::SUB && "Unexpected operation!");
+ // (Z-X) == X --> Z == X<<1
+ SDValue SH = DAG.getNode(ISD::SHL, dl, N1.getValueType(), N1,
DAG.getConstant(1, getShiftAmountTy(N1.getValueType())));
- if (!DCI.isCalledByLegalizer())
- DCI.AddToWorklist(SH.getNode());
- return DAG.getSetCC(dl, VT, N0.getOperand(0), SH, Cond);
+ if (!DCI.isCalledByLegalizer())
+ DCI.AddToWorklist(SH.getNode());
+ return DAG.getSetCC(dl, VT, N0.getOperand(0), SH, Cond);
+ }
}
}
}
generated by cgit v1.1 at 2025-08-15 17:20:05 +0000