#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/MRegisterInfo.h"
+#include "llvm/DerivedTypes.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Support/MathExtras.h"
TargetLowering::TargetLowering(TargetMachine &tm)
: TM(tm), TD(TM.getTargetData()) {
- assert(ISD::BUILTIN_OP_END <= 128 &&
+ assert(ISD::BUILTIN_OP_END <= 156 &&
"Fixed size array in TargetLowering is not large enough!");
// All operations default to being supported.
memset(OpActions, 0, sizeof(OpActions));
ShiftAmountTy = SetCCResultTy = PointerTy = getValueType(TD.getIntPtrType());
ShiftAmtHandling = Undefined;
memset(RegClassForVT, 0,MVT::LAST_VALUETYPE*sizeof(TargetRegisterClass*));
+ memset(TargetDAGCombineArray, 0,
+ sizeof(TargetDAGCombineArray)/sizeof(TargetDAGCombineArray[0]));
maxStoresPerMemset = maxStoresPerMemcpy = maxStoresPerMemmove = 8;
allowUnalignedMemoryAccesses = false;
UseUnderscoreSetJmpLongJmp = false;
// Set MVT::Vector to always be Expanded
SetValueTypeAction(MVT::Vector, Expand, *this, TransformToType,
ValueTypeActions);
+
+ // Loop over all of the legal vector value types, specifying an identity type
+ // transformation.
+ for (unsigned i = MVT::FIRST_VECTOR_VALUETYPE;
+ i <= MVT::LAST_VECTOR_VALUETYPE; ++i) {
+ if (isTypeLegal((MVT::ValueType)i))
+ TransformToType[i] = (MVT::ValueType)i;
+ }
assert(isTypeLegal(MVT::f64) && "Target does not support FP?");
TransformToType[MVT::f64] = MVT::f64;
return NULL;
}
+/// getPackedTypeBreakdown - Packed types are broken down into some number of
+/// legal scalar types. For example, <8 x float> maps to 2 MVT::v2f32 values
+/// with Altivec or SSE1, or 8 promoted MVT::f64 values with the X86 FP stack.
+///
+/// This method returns the number and type of the resultant breakdown.
+///
+unsigned TargetLowering::getPackedTypeBreakdown(const PackedType *PTy,
+ MVT::ValueType &PTyElementVT,
+ MVT::ValueType &PTyLegalElementVT) const {
+ // Figure out the right, legal destination reg to copy into.
+ unsigned NumElts = PTy->getNumElements();
+ MVT::ValueType EltTy = getValueType(PTy->getElementType());
+
+ unsigned NumVectorRegs = 1;
+
+ // Divide the input until we get to a supported size. This will always
+ // end with a scalar if the target doesn't support vectors.
+ while (NumElts > 1 && !isTypeLegal(getVectorType(EltTy, NumElts))) {
+ NumElts >>= 1;
+ NumVectorRegs <<= 1;
+ }
+
+ MVT::ValueType VT;
+ if (NumElts == 1) {
+ VT = EltTy;
+ } else {
+ VT = getVectorType(EltTy, NumElts);
+ }
+ PTyElementVT = VT;
+
+ MVT::ValueType DestVT = getTypeToTransformTo(VT);
+ PTyLegalElementVT = DestVT;
+ if (DestVT < VT) {
+ // Value is expanded, e.g. i64 -> i16.
+ return NumVectorRegs*(MVT::getSizeInBits(VT)/MVT::getSizeInBits(DestVT));
+ } else {
+ // Otherwise, promotion or legal types use the same number of registers as
+ // the vector decimated to the appropriate level.
+ return NumVectorRegs;
+ }
+
+ return DestVT;
+}
+
//===----------------------------------------------------------------------===//
// Optimization Methods
//===----------------------------------------------------------------------===//
/// constant and return true.
bool TargetLowering::TargetLoweringOpt::ShrinkDemandedConstant(SDOperand Op,
uint64_t Demanded) {
- // FIXME: ISD::SELECT
+ // FIXME: ISD::SELECT, ISD::SELECT_CC
switch(Op.getOpcode()) {
default: break;
case ISD::AND:
// We know all of the bits for a constant!
KnownOne = cast<ConstantSDNode>(Op)->getValue() & DemandedMask;
KnownZero = ~KnownOne & DemandedMask;
- return false;
+ return false; // Don't fall through, will infinitely loop.
case ISD::AND:
- // If either the LHS or the RHS are Zero, the result is zero.
+ // If the RHS is a constant, check to see if the LHS would be zero without
+ // using the bits from the RHS. Below, we use knowledge about the RHS to
+ // simplify the LHS, here we're using information from the LHS to simplify
+ // the RHS.
+ if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
+ uint64_t LHSZero, LHSOne;
+ ComputeMaskedBits(Op.getOperand(0), DemandedMask,
+ LHSZero, LHSOne, Depth+1);
+ // If the LHS already has zeros where RHSC does, this and is dead.
+ if ((LHSZero & DemandedMask) == (~RHSC->getValue() & DemandedMask))
+ return TLO.CombineTo(Op, Op.getOperand(0));
+ // If any of the set bits in the RHS are known zero on the LHS, shrink
+ // the constant.
+ if (TLO.ShrinkDemandedConstant(Op, ~LHSZero & DemandedMask))
+ return true;
+ }
+
if (SimplifyDemandedBits(Op.getOperand(1), DemandedMask, KnownZero,
KnownOne, TLO, Depth+1))
return true;
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
- // If something is known zero on the RHS, the bits aren't demanded on the
- // LHS.
if (SimplifyDemandedBits(Op.getOperand(0), DemandedMask & ~KnownZero,
KnownZero2, KnownOne2, TLO, Depth+1))
return true;
// If the RHS is a constant, see if we can simplify it.
if (TLO.ShrinkDemandedConstant(Op, DemandedMask & ~KnownZero2))
return true;
-
+
// Output known-1 bits are only known if set in both the LHS & RHS.
KnownOne &= KnownOne2;
// Output known-0 are known to be clear if zero in either the LHS | RHS.
if (TLO.ShrinkDemandedConstant(Op, DemandedMask))
return true;
+ // Only known if known in both the LHS and RHS.
+ KnownOne &= KnownOne2;
+ KnownZero &= KnownZero2;
+ break;
+ case ISD::SELECT_CC:
+ if (SimplifyDemandedBits(Op.getOperand(3), DemandedMask, KnownZero,
+ KnownOne, TLO, Depth+1))
+ return true;
+ if (SimplifyDemandedBits(Op.getOperand(2), DemandedMask, KnownZero2,
+ KnownOne2, TLO, Depth+1))
+ return true;
+ assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
+ assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
+
+ // If the operands are constants, see if we can simplify them.
+ if (TLO.ShrinkDemandedConstant(Op, DemandedMask))
+ return true;
+
// Only known if known in both the LHS and RHS.
KnownOne &= KnownOne2;
KnownZero &= KnownZero2;
MVT::ValueType VT = Op.getValueType();
MVT::ValueType EVT = cast<VTSDNode>(Op.getOperand(1))->getVT();
- // Sign or Zero extension. Compute the bits in the result that are not
+ // Sign extension. Compute the demanded bits in the result that are not
// present in the input.
- uint64_t NotIn = ~MVT::getIntVTBitMask(EVT);
- uint64_t NewBits = MVT::getIntVTBitMask(VT) & NotIn;
+ uint64_t NewBits = ~MVT::getIntVTBitMask(EVT) & DemandedMask;
- // Sign extension.
+ // If none of the extended bits are demanded, eliminate the sextinreg.
+ if (NewBits == 0)
+ return TLO.CombineTo(Op, Op.getOperand(0));
+
uint64_t InSignBit = MVT::getIntVTSignBit(EVT);
int64_t InputDemandedBits = DemandedMask & MVT::getIntVTBitMask(EVT);
- // If any of the sign extended bits are demanded, we know that the sign
+ // Since the sign extended bits are demanded, we know that the sign
// bit is demanded.
- if (NewBits & DemandedMask)
- InputDemandedBits |= InSignBit;
+ InputDemandedBits |= InSignBit;
if (SimplifyDemandedBits(Op.getOperand(0), InputDemandedBits,
KnownZero, KnownOne, TLO, Depth+1))
// If the sign bit of the input is known set or clear, then we know the
// top bits of the result.
- // If the input sign bit is known zero, or if the NewBits are not demanded
- // convert this into a zero extension.
- if ((KnownZero & InSignBit) || (NewBits & ~DemandedMask) == NewBits) {
- return TLO.CombineTo(Op, Op.getOperand(0));
- } else if (KnownOne & InSignBit) { // Input sign bit known set
+ // If the input sign bit is known zero, convert this into a zero extension.
+ if (KnownZero & InSignBit)
+ return TLO.CombineTo(Op,
+ TLO.DAG.getZeroExtendInReg(Op.getOperand(0), EVT));
+
+ if (KnownOne & InSignBit) { // Input sign bit known set
KnownOne |= NewBits;
KnownZero &= ~NewBits;
- } else { // Input sign bit unknown
+ } else { // Input sign bit unknown
KnownZero &= ~NewBits;
KnownOne &= ~NewBits;
}
break;
}
- case ISD::ADD:
- if (ConstantSDNode *AA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
- if (SimplifyDemandedBits(Op.getOperand(0), DemandedMask, KnownZero,
- KnownOne, TLO, Depth+1))
- return true;
- // Compute the KnownOne/KnownZero masks for the constant, so we can set
- // KnownZero appropriately if we're adding a constant that has all low
- // bits cleared.
- ComputeMaskedBits(Op.getOperand(1),
- MVT::getIntVTBitMask(Op.getValueType()),
- KnownZero2, KnownOne2, Depth+1);
-
- uint64_t KnownZeroOut = std::min(CountTrailingZeros_64(~KnownZero),
- CountTrailingZeros_64(~KnownZero2));
- KnownZero = (1ULL << KnownZeroOut) - 1;
- KnownOne = 0;
-
- SDOperand SH = Op.getOperand(0);
- // fold (add (shl x, c1), (shl c2, c1)) -> (shl (add x, c2), c1)
- if (KnownZero && SH.getOpcode() == ISD::SHL && SH.Val->hasOneUse() &&
- Op.Val->hasOneUse()) {
- if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(SH.getOperand(1))) {
- MVT::ValueType VT = Op.getValueType();
- unsigned ShiftAmt = SA->getValue();
- uint64_t AddAmt = AA->getValue();
- uint64_t AddShr = AddAmt >> ShiftAmt;
- if (AddAmt == (AddShr << ShiftAmt)) {
- SDOperand ADD = TLO.DAG.getNode(ISD::ADD, VT, SH.getOperand(0),
- TLO.DAG.getConstant(AddShr, VT));
- SDOperand SHL = TLO.DAG.getNode(ISD::SHL, VT, ADD,SH.getOperand(1));
- return TLO.CombineTo(Op, SHL);
- }
- }
- }
- }
- break;
case ISD::CTTZ:
case ISD::CTLZ:
case ISD::CTPOP: {
KnownOne = 0;
break;
}
+ case ISD::ZEXTLOAD: {
+ MVT::ValueType VT = cast<VTSDNode>(Op.getOperand(3))->getVT();
+ KnownZero |= ~MVT::getIntVTBitMask(VT) & DemandedMask;
+ break;
+ }
+ case ISD::ZERO_EXTEND: {
+ uint64_t InMask = MVT::getIntVTBitMask(Op.getOperand(0).getValueType());
+
+ // If none of the top bits are demanded, convert this into an any_extend.
+ uint64_t NewBits = (~InMask) & DemandedMask;
+ if (NewBits == 0)
+ return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::ANY_EXTEND,
+ Op.getValueType(),
+ Op.getOperand(0)));
+
+ if (SimplifyDemandedBits(Op.getOperand(0), DemandedMask & InMask,
+ KnownZero, KnownOne, TLO, Depth+1))
+ return true;
+ assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
+ KnownZero |= NewBits;
+ break;
}
+ case ISD::SIGN_EXTEND: {
+ MVT::ValueType InVT = Op.getOperand(0).getValueType();
+ uint64_t InMask = MVT::getIntVTBitMask(InVT);
+ uint64_t InSignBit = MVT::getIntVTSignBit(InVT);
+ uint64_t NewBits = (~InMask) & DemandedMask;
+
+ // If none of the top bits are demanded, convert this into an any_extend.
+ if (NewBits == 0)
+ return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::ANY_EXTEND,Op.getValueType(),
+ Op.getOperand(0)));
+
+ // Since some of the sign extended bits are demanded, we know that the sign
+ // bit is demanded.
+ uint64_t InDemandedBits = DemandedMask & InMask;
+ InDemandedBits |= InSignBit;
+
+ if (SimplifyDemandedBits(Op.getOperand(0), InDemandedBits, KnownZero,
+ KnownOne, TLO, Depth+1))
+ return true;
+
+ // If the sign bit is known zero, convert this to a zero extend.
+ if (KnownZero & InSignBit)
+ return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::ZERO_EXTEND,
+ Op.getValueType(),
+ Op.getOperand(0)));
+
+ // If the sign bit is known one, the top bits match.
+ if (KnownOne & InSignBit) {
+ KnownOne |= NewBits;
+ KnownZero &= ~NewBits;
+ } else { // Otherwise, top bits aren't known.
+ KnownOne &= ~NewBits;
+ KnownZero &= ~NewBits;
+ }
+ break;
+ }
+ case ISD::ANY_EXTEND: {
+ uint64_t InMask = MVT::getIntVTBitMask(Op.getOperand(0).getValueType());
+ if (SimplifyDemandedBits(Op.getOperand(0), DemandedMask & InMask,
+ KnownZero, KnownOne, TLO, Depth+1))
+ return true;
+ assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
+ break;
+ }
+ case ISD::AssertZext: {
+ MVT::ValueType VT = cast<VTSDNode>(Op.getOperand(1))->getVT();
+ uint64_t InMask = MVT::getIntVTBitMask(VT);
+ if (SimplifyDemandedBits(Op.getOperand(0), DemandedMask & InMask,
+ KnownZero, KnownOne, TLO, Depth+1))
+ return true;
+ assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
+ KnownZero |= ~InMask & DemandedMask;
+ break;
+ }
+ case ISD::ADD:
+ case ISD::SUB:
+ // Just use ComputeMaskedBits to compute output bits, there are no
+ // simplifications that can be done here, and sub always demands all input
+ // bits.
+ ComputeMaskedBits(Op, DemandedMask, KnownZero, KnownOne, Depth);
+ break;
+ }
+
+ // If we know the value of all of the demanded bits, return this as a
+ // constant.
+ if ((DemandedMask & (KnownZero|KnownOne)) == DemandedMask)
+ return TLO.CombineTo(Op, TLO.DAG.getConstant(KnownOne, Op.getValueType()));
+
return false;
}
}
}
return;
+ case ISD::SIGN_EXTEND_INREG: {
+ MVT::ValueType VT = Op.getValueType();
+ MVT::ValueType EVT = cast<VTSDNode>(Op.getOperand(1))->getVT();
+
+ // Sign extension. Compute the demanded bits in the result that are not
+ // present in the input.
+ uint64_t NewBits = ~MVT::getIntVTBitMask(EVT) & Mask;
+
+ uint64_t InSignBit = MVT::getIntVTSignBit(EVT);
+ int64_t InputDemandedBits = Mask & MVT::getIntVTBitMask(EVT);
+
+ // If the sign extended bits are demanded, we know that the sign
+ // bit is demanded.
+ if (NewBits)
+ InputDemandedBits |= InSignBit;
+
+ ComputeMaskedBits(Op.getOperand(0), InputDemandedBits,
+ KnownZero, KnownOne, Depth+1);
+ assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
+
+ // If the sign bit of the input is known set or clear, then we know the
+ // top bits of the result.
+ if (KnownZero & InSignBit) { // Input sign bit known clear
+ KnownZero |= NewBits;
+ KnownOne &= ~NewBits;
+ } else if (KnownOne & InSignBit) { // Input sign bit known set
+ KnownOne |= NewBits;
+ KnownZero &= ~NewBits;
+ } else { // Input sign bit unknown
+ KnownZero &= ~NewBits;
+ KnownOne &= ~NewBits;
+ }
+ return;
+ }
case ISD::CTTZ:
case ISD::CTLZ:
case ISD::CTPOP: {
return;
}
case ISD::ZEXTLOAD: {
- unsigned SrcBits =
- MVT::getSizeInBits(cast<VTSDNode>(Op.getOperand(3))->getVT());
- KnownZero |= ~((1ULL << SrcBits)-1);
+ MVT::ValueType VT = cast<VTSDNode>(Op.getOperand(3))->getVT();
+ KnownZero |= ~MVT::getIntVTBitMask(VT) & Mask;
return;
}
case ISD::ZERO_EXTEND: {
- unsigned SrcBits =
- MVT::getSizeInBits(Op.getOperand(0).getValueType());
- KnownZero |= ~((1ULL << SrcBits)-1);
+ uint64_t InMask = MVT::getIntVTBitMask(Op.getOperand(0).getValueType());
+ uint64_t NewBits = (~InMask) & Mask;
+ ComputeMaskedBits(Op.getOperand(0), Mask & InMask, KnownZero,
+ KnownOne, Depth+1);
+ KnownZero |= NewBits & Mask;
+ KnownOne &= ~NewBits;
+ return;
+ }
+ case ISD::SIGN_EXTEND: {
+ MVT::ValueType InVT = Op.getOperand(0).getValueType();
+ unsigned InBits = MVT::getSizeInBits(InVT);
+ uint64_t InMask = MVT::getIntVTBitMask(InVT);
+ uint64_t InSignBit = 1ULL << (InBits-1);
+ uint64_t NewBits = (~InMask) & Mask;
+ uint64_t InDemandedBits = Mask & InMask;
+
+ // If any of the sign extended bits are demanded, we know that the sign
+ // bit is demanded.
+ if (NewBits & Mask)
+ InDemandedBits |= InSignBit;
+
+ ComputeMaskedBits(Op.getOperand(0), InDemandedBits, KnownZero,
+ KnownOne, Depth+1);
+ // If the sign bit is known zero or one, the top bits match.
+ if (KnownZero & InSignBit) {
+ KnownZero |= NewBits;
+ KnownOne &= ~NewBits;
+ } else if (KnownOne & InSignBit) {
+ KnownOne |= NewBits;
+ KnownZero &= ~NewBits;
+ } else { // Otherwise, top bits aren't known.
+ KnownOne &= ~NewBits;
+ KnownZero &= ~NewBits;
+ }
return;
}
case ISD::ANY_EXTEND: {
- unsigned SrcBits =
- MVT::getSizeInBits(Op.getOperand(0).getValueType());
- KnownZero &= ((1ULL << SrcBits)-1);
- KnownOne &= ((1ULL << SrcBits)-1);
+ MVT::ValueType VT = Op.getOperand(0).getValueType();
+ ComputeMaskedBits(Op.getOperand(0), Mask & MVT::getIntVTBitMask(VT),
+ KnownZero, KnownOne, Depth+1);
return;
}
case ISD::AssertZext: {
- unsigned SrcBits =
- MVT::getSizeInBits(cast<VTSDNode>(Op.getOperand(1))->getVT());
- KnownZero |= ~((1ULL << SrcBits)-1);
+ MVT::ValueType VT = cast<VTSDNode>(Op.getOperand(1))->getVT();
+ uint64_t InMask = MVT::getIntVTBitMask(VT);
+ ComputeMaskedBits(Op.getOperand(0), Mask & InMask, KnownZero,
+ KnownOne, Depth+1);
+ KnownZero |= (~InMask) & Mask;
return;
}
case ISD::ADD: {
assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
// Output known-0 bits are known if clear or set in both the low clear bits
- // common to both LHS & RHS;
+ // common to both LHS & RHS. For example, 8+(X<<3) is known to have the
+ // low 3 bits clear.
uint64_t KnownZeroOut = std::min(CountTrailingZeros_64(~KnownZero),
CountTrailingZeros_64(~KnownZero2));
KnownOne = 0;
return;
}
- case ISD::SUB:
+ case ISD::SUB: {
+ ConstantSDNode *CLHS = dyn_cast<ConstantSDNode>(Op.getOperand(0));
+ if (!CLHS) return;
+
// We know that the top bits of C-X are clear if X contains less bits
// than C (i.e. no wrap-around can happen). For example, 20-X is
// positive if we can prove that X is >= 0 and < 16.
+ MVT::ValueType VT = CLHS->getValueType(0);
+ if ((CLHS->getValue() & MVT::getIntVTSignBit(VT)) == 0) { // sign bit clear
+ unsigned NLZ = CountLeadingZeros_64(CLHS->getValue()+1);
+ uint64_t MaskV = (1ULL << (63-NLZ))-1; // NLZ can't be 64 with no sign bit
+ MaskV = ~MaskV & MVT::getIntVTBitMask(VT);
+ ComputeMaskedBits(Op.getOperand(1), MaskV, KnownZero, KnownOne, Depth+1);
+
+ // If all of the MaskV bits are known to be zero, then we know the output
+ // top bits are zero, because we now know that the output is from [0-C].
+ if ((KnownZero & MaskV) == MaskV) {
+ unsigned NLZ2 = CountLeadingZeros_64(CLHS->getValue());
+ KnownZero = ~((1ULL << (64-NLZ2))-1) & Mask; // Top bits known zero.
+ KnownOne = 0; // No one bits known.
+ } else {
+ KnownOne = KnownOne = 0; // Otherwise, nothing known.
+ }
+ }
return;
+ }
default:
// Allow the target to implement this method for its nodes.
if (Op.getOpcode() >= ISD::BUILTIN_OP_END)
KnownOne = 0;
}
+SDOperand TargetLowering::
+PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const {
+ // Default implementation: no optimization.
+ return SDOperand();
+}
+
//===----------------------------------------------------------------------===//
// Inline Assembler Implementation Methods
//===----------------------------------------------------------------------===//
return std::pair<unsigned, const TargetRegisterClass*>(0, 0);
}
+
+//===----------------------------------------------------------------------===//
+// Loop Strength Reduction hooks
+//===----------------------------------------------------------------------===//
+
+/// isLegalAddressImmediate - Return true if the integer value or
+/// GlobalValue can be used as the offset of the target addressing mode.
+bool TargetLowering::isLegalAddressImmediate(int64_t V) const {
+ return false;
+}
+bool TargetLowering::isLegalAddressImmediate(GlobalValue *GV) const {
+ return false;
+}