// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
-//
-// This file describes how to lower LLVM code to machine code. This has two
-// main components:
-//
-// 1. Which ValueTypes are natively supported by the target.
-// 2. Which operations are supported for supported ValueTypes.
-// 3. Cost thresholds for alternative implementations of certain operations.
-//
-// In addition it has a few other components, like information about FP
-// immediates.
-//
+///
+/// \file
+/// This file describes how to lower LLVM code to machine code. This has two
+/// main components:
+///
+/// 1. Which ValueTypes are natively supported by the target.
+/// 2. Which operations are supported for supported ValueTypes.
+/// 3. Cost thresholds for alternative implementations of certain operations.
+///
+/// In addition it has a few other components, like information about FP
+/// immediates.
+///
//===----------------------------------------------------------------------===//
#ifndef LLVM_TARGET_TARGETLOWERING_H
#define LLVM_TARGET_TARGETLOWERING_H
#include "llvm/ADT/DenseMap.h"
-#include "llvm/AddressingMode.h"
-#include "llvm/Attributes.h"
-#include "llvm/CallingConv.h"
+#include "llvm/CodeGen/DAGCombine.h"
#include "llvm/CodeGen/RuntimeLibcalls.h"
#include "llvm/CodeGen/SelectionDAGNodes.h"
-#include "llvm/InlineAsm.h"
-#include "llvm/Support/CallSite.h"
-#include "llvm/Support/DebugLoc.h"
+#include "llvm/IR/Attributes.h"
+#include "llvm/IR/CallSite.h"
+#include "llvm/IR/CallingConv.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/InlineAsm.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/Target/TargetCallingConv.h"
#include "llvm/Target/TargetMachine.h"
#include <climits>
class MachineFunction;
class MachineInstr;
class MachineJumpTableInfo;
+ class MachineLoop;
+ class Mangler;
class MCContext;
class MCExpr;
+ class MCSymbol;
template<typename T> class SmallVectorImpl;
class DataLayout;
class TargetRegisterClass;
};
}
+/// This base class for TargetLowering contains the SelectionDAG-independent
+/// parts that can be used from the rest of CodeGen.
+class TargetLoweringBase {
+ TargetLoweringBase(const TargetLoweringBase&) LLVM_DELETED_FUNCTION;
+ void operator=(const TargetLoweringBase&) LLVM_DELETED_FUNCTION;
-//===----------------------------------------------------------------------===//
-/// TargetLowering - This class defines information used to lower LLVM code to
-/// legal SelectionDAG operators that the target instruction selector can accept
-/// natively.
-///
-/// This class also defines callbacks that targets must implement to lower
-/// target-specific constructs to SelectionDAG operators.
-///
-class TargetLowering {
- TargetLowering(const TargetLowering&) LLVM_DELETED_FUNCTION;
- void operator=(const TargetLowering&) LLVM_DELETED_FUNCTION;
public:
- /// LegalizeAction - This enum indicates whether operations are valid for a
- /// target, and if not, what action should be used to make them valid.
+ /// This enum indicates whether operations are valid for a target, and if not,
+ /// what action should be used to make them valid.
enum LegalizeAction {
Legal, // The target natively supports this operation.
Promote, // This operation should be executed in a larger type.
Custom // Use the LowerOperation hook to implement custom lowering.
};
- /// LegalizeTypeAction - This enum indicates whether a types are legal for a
- /// target, and if not, what action should be used to make them valid.
+ /// This enum indicates whether a types are legal for a target, and if not,
+ /// what action should be used to make them valid.
enum LegalizeTypeAction {
TypeLegal, // The target natively supports this type.
TypePromoteInteger, // Replace this integer with a larger one.
/// in order to type-legalize it.
typedef std::pair<LegalizeTypeAction, EVT> LegalizeKind;
- enum BooleanContent { // How the target represents true/false values.
+ /// Enum that describes how the target represents true/false values.
+ enum BooleanContent {
UndefinedBooleanContent, // Only bit 0 counts, the rest can hold garbage.
ZeroOrOneBooleanContent, // All bits zero except for bit 0.
ZeroOrNegativeOneBooleanContent // All bits equal to bit 0.
};
+ /// Enum that describes what type of support for selects the target has.
enum SelectSupportKind {
ScalarValSelect, // The target supports scalar selects (ex: cmov).
ScalarCondVectorVal, // The target supports selects with a scalar condition
llvm_unreachable("Invalid content kind");
}
- /// NOTE: The constructor takes ownership of TLOF.
- explicit TargetLowering(const TargetMachine &TM,
- const TargetLoweringObjectFile *TLOF);
- virtual ~TargetLowering();
+ /// NOTE: The TargetMachine owns TLOF.
+ explicit TargetLoweringBase(const TargetMachine &TM);
+ virtual ~TargetLoweringBase() {}
+
+protected:
+ /// \brief Initialize all of the actions to default values.
+ void initActions();
+public:
const TargetMachine &getTargetMachine() const { return TM; }
- const DataLayout *getDataLayout() const { return TD; }
- const TargetLoweringObjectFile &getObjFileLowering() const { return TLOF; }
+ const DataLayout *getDataLayout() const { return DL; }
+ const TargetLoweringObjectFile &getObjFileLowering() const {
+ return *TM.getObjFileLowering();
+ }
bool isBigEndian() const { return !IsLittleEndian; }
bool isLittleEndian() const { return IsLittleEndian; }
- // Return the pointer type for the given address space, defaults to
- // the pointer type from the data layout.
- // FIXME: The default needs to be removed once all the code is updated.
- virtual MVT getPointerTy(uint32_t AS = 0) const { return PointerTy; }
- virtual MVT getShiftAmountTy(EVT LHSTy) const;
-
- /// isSelectExpensive - Return true if the select operation is expensive for
- /// this target.
+
+ /// Return the pointer type for the given address space, defaults to
+ /// the pointer type from the data layout.
+ /// FIXME: The default needs to be removed once all the code is updated.
+ virtual MVT getPointerTy(uint32_t /*AS*/ = 0) const;
+ unsigned getPointerSizeInBits(uint32_t AS = 0) const;
+ unsigned getPointerTypeSizeInBits(Type *Ty) const;
+ virtual MVT getScalarShiftAmountTy(EVT LHSTy) const;
+
+ EVT getShiftAmountTy(EVT LHSTy) const;
+
+ /// Returns the type to be used for the index operand of:
+ /// ISD::INSERT_VECTOR_ELT, ISD::EXTRACT_VECTOR_ELT,
+ /// ISD::INSERT_SUBVECTOR, and ISD::EXTRACT_SUBVECTOR
+ virtual MVT getVectorIdxTy() const {
+ return getPointerTy();
+ }
+
+ /// Return true if the select operation is expensive for this target.
bool isSelectExpensive() const { return SelectIsExpensive; }
- virtual bool isSelectSupported(SelectSupportKind kind) const { return true; }
+ virtual bool isSelectSupported(SelectSupportKind /*kind*/) const {
+ return true;
+ }
+
+ /// Return true if multiple condition registers are available.
+ bool hasMultipleConditionRegisters() const {
+ return HasMultipleConditionRegisters;
+ }
- /// shouldSplitVectorElementType - Return true if a vector of the given type
- /// should be split (TypeSplitVector) instead of promoted
- /// (TypePromoteInteger) during type legalization.
- virtual bool shouldSplitVectorElementType(EVT VT) const { return false; }
+ /// Return true if the target has BitExtract instructions.
+ bool hasExtractBitsInsn() const { return HasExtractBitsInsn; }
+
+ /// Return the preferred vector type legalization action.
+ virtual TargetLoweringBase::LegalizeTypeAction
+ getPreferredVectorAction(EVT VT) const {
+ // The default action for one element vectors is to scalarize
+ if (VT.getVectorNumElements() == 1)
+ return TypeScalarizeVector;
+ // The default action for other vectors is to promote
+ return TypePromoteInteger;
+ }
+
+ // There are two general methods for expanding a BUILD_VECTOR node:
+ // 1. Use SCALAR_TO_VECTOR on the defined scalar values and then shuffle
+ // them together.
+ // 2. Build the vector on the stack and then load it.
+ // If this function returns true, then method (1) will be used, subject to
+ // the constraint that all of the necessary shuffles are legal (as determined
+ // by isShuffleMaskLegal). If this function returns false, then method (2) is
+ // always used. The vector type, and the number of defined values, are
+ // provided.
+ virtual bool
+ shouldExpandBuildVectorWithShuffles(EVT /* VT */,
+ unsigned DefinedValues) const {
+ return DefinedValues < 3;
+ }
- /// isIntDivCheap() - Return true if integer divide is usually cheaper than
- /// a sequence of several shifts, adds, and multiplies for this target.
+ /// Return true if integer divide is usually cheaper than a sequence of
+ /// several shifts, adds, and multiplies for this target.
bool isIntDivCheap() const { return IntDivIsCheap; }
- /// isSlowDivBypassed - Returns true if target has indicated at least one
- /// type should be bypassed.
+ /// Return true if sqrt(x) is as cheap or cheaper than 1 / rsqrt(x)
+ bool isFsqrtCheap() const {
+ return FsqrtIsCheap;
+ }
+
+ /// Returns true if target has indicated at least one type should be bypassed.
bool isSlowDivBypassed() const { return !BypassSlowDivWidths.empty(); }
- /// getBypassSlowDivTypes - Returns map of slow types for division or
- /// remainder with corresponding fast types
+ /// Returns map of slow types for division or remainder with corresponding
+ /// fast types
const DenseMap<unsigned int, unsigned int> &getBypassSlowDivWidths() const {
return BypassSlowDivWidths;
}
- /// isPow2DivCheap() - Return true if pow2 div is cheaper than a chain of
- /// srl/add/sra.
- bool isPow2DivCheap() const { return Pow2DivIsCheap; }
+ /// Return true if pow2 sdiv is cheaper than a chain of sra/srl/add/sra.
+ bool isPow2SDivCheap() const { return Pow2SDivIsCheap; }
- /// isJumpExpensive() - Return true if Flow Control is an expensive operation
- /// that should be avoided.
+ /// Return true if Flow Control is an expensive operation that should be
+ /// avoided.
bool isJumpExpensive() const { return JumpIsExpensive; }
- /// isPredictableSelectExpensive - Return true if selects are only cheaper
- /// than branches if the branch is unlikely to be predicted right.
+ /// Return true if selects are only cheaper than branches if the branch is
+ /// unlikely to be predicted right.
bool isPredictableSelectExpensive() const {
- return predictableSelectIsExpensive;
+ return PredictableSelectIsExpensive;
+ }
+
+ /// isLoadBitCastBeneficial() - Return true if the following transform
+ /// is beneficial.
+ /// fold (conv (load x)) -> (load (conv*)x)
+ /// On architectures that don't natively support some vector loads efficiently,
+ /// casting the load to a smaller vector of larger types and loading
+ /// is more efficient, however, this can be undone by optimizations in
+ /// dag combiner.
+ virtual bool isLoadBitCastBeneficial(EVT /* Load */, EVT /* Bitcast */) const {
+ return true;
+ }
+
+ /// \brief Return true if it is cheap to speculate a call to intrinsic cttz.
+ virtual bool isCheapToSpeculateCttz() const {
+ return false;
+ }
+
+ /// \brief Return true if it is cheap to speculate a call to intrinsic ctlz.
+ virtual bool isCheapToSpeculateCtlz() const {
+ return false;
+ }
+
+ /// \brief Return if the target supports combining a
+ /// chain like:
+ /// \code
+ /// %andResult = and %val1, #imm-with-one-bit-set;
+ /// %icmpResult = icmp %andResult, 0
+ /// br i1 %icmpResult, label %dest1, label %dest2
+ /// \endcode
+ /// into a single machine instruction of a form like:
+ /// \code
+ /// brOnBitSet %register, #bitNumber, dest
+ /// \endcode
+ bool isMaskAndBranchFoldingLegal() const {
+ return MaskAndBranchFoldingIsLegal;
+ }
+
+ /// \brief Return true if the target wants to use the optimization that
+ /// turns ext(promotableInst1(...(promotableInstN(load)))) into
+ /// promotedInst1(...(promotedInstN(ext(load)))).
+ bool enableExtLdPromotion() const { return EnableExtLdPromotion; }
+
+ /// Return true if the target can combine store(extractelement VectorTy,
+ /// Idx).
+ /// \p Cost[out] gives the cost of that transformation when this is true.
+ virtual bool canCombineStoreAndExtract(Type *VectorTy, Value *Idx,
+ unsigned &Cost) const {
+ return false;
+ }
+
+ /// Return true if target supports floating point exceptions.
+ bool hasFloatingPointExceptions() const {
+ return HasFloatingPointExceptions;
}
- /// getSetCCResultType - Return the ValueType of the result of SETCC
- /// operations. Also used to obtain the target's preferred type for
- /// the condition operand of SELECT and BRCOND nodes. In the case of
- /// BRCOND the argument passed is MVT::Other since there are no other
- /// operands to get a type hint from.
- virtual EVT getSetCCResultType(EVT VT) const;
+ /// Return true if target always beneficiates from combining into FMA for a
+ /// given value type. This must typically return false on targets where FMA
+ /// takes more cycles to execute than FADD.
+ virtual bool enableAggressiveFMAFusion(EVT VT) const {
+ return false;
+ }
- /// getCmpLibcallReturnType - Return the ValueType for comparison
- /// libcalls. Comparions libcalls include floating point comparion calls,
- /// and Ordered/Unordered check calls on floating point numbers.
+ /// Return the ValueType of the result of SETCC operations.
+ virtual EVT getSetCCResultType(LLVMContext &Context, EVT VT) const;
+
+ /// Return the ValueType for comparison libcalls. Comparions libcalls include
+ /// floating point comparion calls, and Ordered/Unordered check calls on
+ /// floating point numbers.
virtual
MVT::SimpleValueType getCmpLibcallReturnType() const;
- /// getBooleanContents - For targets without i1 registers, this gives the
- /// nature of the high-bits of boolean values held in types wider than i1.
+ /// For targets without i1 registers, this gives the nature of the high-bits
+ /// of boolean values held in types wider than i1.
+ ///
/// "Boolean values" are special true/false values produced by nodes like
/// SETCC and consumed (as the condition) by nodes like SELECT and BRCOND.
- /// Not to be confused with general values promoted from i1.
- /// Some cpus distinguish between vectors of boolean and scalars; the isVec
- /// parameter selects between the two kinds. For example on X86 a scalar
- /// boolean should be zero extended from i1, while the elements of a vector
- /// of booleans should be sign extended from i1.
- BooleanContent getBooleanContents(bool isVec) const {
- return isVec ? BooleanVectorContents : BooleanContents;
+ /// Not to be confused with general values promoted from i1. Some cpus
+ /// distinguish between vectors of boolean and scalars; the isVec parameter
+ /// selects between the two kinds. For example on X86 a scalar boolean should
+ /// be zero extended from i1, while the elements of a vector of booleans
+ /// should be sign extended from i1.
+ ///
+ /// Some cpus also treat floating point types the same way as they treat
+ /// vectors instead of the way they treat scalars.
+ BooleanContent getBooleanContents(bool isVec, bool isFloat) const {
+ if (isVec)
+ return BooleanVectorContents;
+ return isFloat ? BooleanFloatContents : BooleanContents;
+ }
+
+ BooleanContent getBooleanContents(EVT Type) const {
+ return getBooleanContents(Type.isVector(), Type.isFloatingPoint());
}
- /// getSchedulingPreference - Return target scheduling preference.
+ /// Return target scheduling preference.
Sched::Preference getSchedulingPreference() const {
return SchedPreferenceInfo;
}
- /// getSchedulingPreference - Some scheduler, e.g. hybrid, can switch to
- /// different scheduling heuristics for different nodes. This function returns
- /// the preference (or none) for the given node.
+ /// Some scheduler, e.g. hybrid, can switch to different scheduling heuristics
+ /// for different nodes. This function returns the preference (or none) for
+ /// the given node.
virtual Sched::Preference getSchedulingPreference(SDNode *) const {
return Sched::None;
}
- /// getRegClassFor - Return the register class that should be used for the
- /// specified value type.
+ /// Return the register class that should be used for the specified value
+ /// type.
virtual const TargetRegisterClass *getRegClassFor(MVT VT) const {
const TargetRegisterClass *RC = RegClassForVT[VT.SimpleTy];
assert(RC && "This value type is not natively supported!");
return RC;
}
- /// getRepRegClassFor - Return the 'representative' register class for the
- /// specified value type. The 'representative' register class is the largest
- /// legal super-reg register class for the register class of the value type.
- /// For example, on i386 the rep register class for i8, i16, and i32 are GR32;
- /// while the rep register class is GR64 on x86_64.
+ /// Return the 'representative' register class for the specified value
+ /// type.
+ ///
+ /// The 'representative' register class is the largest legal super-reg
+ /// register class for the register class of the value type. For example, on
+ /// i386 the rep register class for i8, i16, and i32 are GR32; while the rep
+ /// register class is GR64 on x86_64.
virtual const TargetRegisterClass *getRepRegClassFor(MVT VT) const {
const TargetRegisterClass *RC = RepRegClassForVT[VT.SimpleTy];
return RC;
}
- /// getRepRegClassCostFor - Return the cost of the 'representative' register
- /// class for the specified value type.
+ /// Return the cost of the 'representative' register class for the specified
+ /// value type.
virtual uint8_t getRepRegClassCostFor(MVT VT) const {
return RepRegClassCostForVT[VT.SimpleTy];
}
- /// isTypeLegal - Return true if the target has native support for the
- /// specified value type. This means that it has a register that directly
- /// holds it without promotions or expansions.
+ /// Return true if the target has native support for the specified value type.
+ /// This means that it has a register that directly holds it without
+ /// promotions or expansions.
bool isTypeLegal(EVT VT) const {
assert(!VT.isSimple() ||
(unsigned)VT.getSimpleVT().SimpleTy < array_lengthof(RegClassForVT));
- return VT.isSimple() && RegClassForVT[VT.getSimpleVT().SimpleTy] != 0;
+ return VT.isSimple() && RegClassForVT[VT.getSimpleVT().SimpleTy] != nullptr;
}
class ValueTypeActionImpl {
public:
ValueTypeActionImpl() {
- std::fill(ValueTypeActions, array_endof(ValueTypeActions), 0);
+ std::fill(std::begin(ValueTypeActions), std::end(ValueTypeActions), 0);
}
LegalizeTypeAction getTypeAction(MVT VT) const {
return ValueTypeActions;
}
- /// getTypeAction - Return how we should legalize values of this type, either
- /// it is already legal (return 'Legal') or we need to promote it to a larger
- /// type (return 'Promote'), or we need to expand it into multiple registers
- /// of smaller integer type (return 'Expand'). 'Custom' is not an option.
+ /// Return how we should legalize values of this type, either it is already
+ /// legal (return 'Legal') or we need to promote it to a larger type (return
+ /// 'Promote'), or we need to expand it into multiple registers of smaller
+ /// integer type (return 'Expand'). 'Custom' is not an option.
LegalizeTypeAction getTypeAction(LLVMContext &Context, EVT VT) const {
return getTypeConversion(Context, VT).first;
}
return ValueTypeActions.getTypeAction(VT);
}
- /// getTypeToTransformTo - For types supported by the target, this is an
- /// identity function. For types that must be promoted to larger types, this
- /// returns the larger type to promote to. For integer types that are larger
- /// than the largest integer register, this contains one step in the expansion
- /// to get to the smaller register. For illegal floating point types, this
- /// returns the integer type to transform to.
+ /// For types supported by the target, this is an identity function. For
+ /// types that must be promoted to larger types, this returns the larger type
+ /// to promote to. For integer types that are larger than the largest integer
+ /// register, this contains one step in the expansion to get to the smaller
+ /// register. For illegal floating point types, this returns the integer type
+ /// to transform to.
EVT getTypeToTransformTo(LLVMContext &Context, EVT VT) const {
return getTypeConversion(Context, VT).second;
}
- /// getTypeToExpandTo - For types supported by the target, this is an
- /// identity function. For types that must be expanded (i.e. integer types
- /// that are larger than the largest integer register or illegal floating
- /// point types), this returns the largest legal type it will be expanded to.
+ /// For types supported by the target, this is an identity function. For
+ /// types that must be expanded (i.e. integer types that are larger than the
+ /// largest integer register or illegal floating point types), this returns
+ /// the largest legal type it will be expanded to.
EVT getTypeToExpandTo(LLVMContext &Context, EVT VT) const {
assert(!VT.isVector());
while (true) {
}
}
- /// getVectorTypeBreakdown - Vector types are broken down into some number of
- /// legal first class types. For example, EVT::v8f32 maps to 2 EVT::v4f32
- /// with Altivec or SSE1, or 8 promoted EVT::f64 values with the X86 FP stack.
- /// Similarly, EVT::v2i64 turns into 4 EVT::i32 values with both PPC and X86.
+ /// Vector types are broken down into some number of legal first class types.
+ /// For example, EVT::v8f32 maps to 2 EVT::v4f32 with Altivec or SSE1, or 8
+ /// promoted EVT::f64 values with the X86 FP stack. Similarly, EVT::v2i64
+ /// turns into 4 EVT::i32 values with both PPC and X86.
///
/// This method returns the number of registers needed, and the VT for each
/// register. It also returns the VT and quantity of the intermediate values
/// before they are promoted/expanded.
- ///
unsigned getVectorTypeBreakdown(LLVMContext &Context, EVT VT,
EVT &IntermediateVT,
unsigned &NumIntermediates,
MVT &RegisterVT) const;
- /// getTgtMemIntrinsic: Given an intrinsic, checks if on the target the
- /// intrinsic will need to map to a MemIntrinsicNode (touches memory). If
- /// this is the case, it returns true and store the intrinsic
- /// information into the IntrinsicInfo that was passed to the function.
struct IntrinsicInfo {
unsigned opc; // target opcode
EVT memVT; // memory VT
const Value* ptrVal; // value representing memory location
int offset; // offset off of ptrVal
+ unsigned size; // the size of the memory location
+ // (taken from memVT if zero)
unsigned align; // alignment
bool vol; // is volatile?
bool readMem; // reads memory?
bool writeMem; // writes memory?
+
+ IntrinsicInfo() : opc(0), ptrVal(nullptr), offset(0), size(0), align(1),
+ vol(false), readMem(false), writeMem(false) {}
};
+ /// Given an intrinsic, checks if on the target the intrinsic will need to map
+ /// to a MemIntrinsicNode (touches memory). If this is the case, it returns
+ /// true and store the intrinsic information into the IntrinsicInfo that was
+ /// passed to the function.
virtual bool getTgtMemIntrinsic(IntrinsicInfo &, const CallInst &,
unsigned /*Intrinsic*/) const {
return false;
}
- /// isFPImmLegal - Returns true if the target can instruction select the
- /// specified FP immediate natively. If false, the legalizer will materialize
- /// the FP immediate as a load from a constant pool.
+ /// Returns true if the target can instruction select the specified FP
+ /// immediate natively. If false, the legalizer will materialize the FP
+ /// immediate as a load from a constant pool.
virtual bool isFPImmLegal(const APFloat &/*Imm*/, EVT /*VT*/) const {
return false;
}
- /// isShuffleMaskLegal - Targets can use this to indicate that they only
- /// support *some* VECTOR_SHUFFLE operations, those with specific masks.
- /// By default, if a target supports the VECTOR_SHUFFLE node, all mask values
- /// are assumed to be legal.
+ /// Targets can use this to indicate that they only support *some*
+ /// VECTOR_SHUFFLE operations, those with specific masks. By default, if a
+ /// target supports the VECTOR_SHUFFLE node, all mask values are assumed to be
+ /// legal.
virtual bool isShuffleMaskLegal(const SmallVectorImpl<int> &/*Mask*/,
EVT /*VT*/) const {
return true;
}
- /// canOpTrap - Returns true if the operation can trap for the value type.
+ /// Returns true if the operation can trap for the value type.
+ ///
/// VT must be a legal type. By default, we optimistically assume most
/// operations don't trap except for divide and remainder.
virtual bool canOpTrap(unsigned Op, EVT VT) const;
- /// isVectorClearMaskLegal - Similar to isShuffleMaskLegal. This is
- /// used by Targets can use this to indicate if there is a suitable
- /// VECTOR_SHUFFLE that can be used to replace a VAND with a constant
- /// pool entry.
+ /// Similar to isShuffleMaskLegal. This is used by Targets can use this to
+ /// indicate if there is a suitable VECTOR_SHUFFLE that can be used to replace
+ /// a VAND with a constant pool entry.
virtual bool isVectorClearMaskLegal(const SmallVectorImpl<int> &/*Mask*/,
EVT /*VT*/) const {
return false;
}
- /// getOperationAction - Return how this operation should be treated: either
- /// it is legal, needs to be promoted to a larger size, needs to be
- /// expanded to some other code sequence, or the target has a custom expander
- /// for it.
+ /// Return how this operation should be treated: either it is legal, needs to
+ /// be promoted to a larger size, needs to be expanded to some other code
+ /// sequence, or the target has a custom expander for it.
LegalizeAction getOperationAction(unsigned Op, EVT VT) const {
if (VT.isExtended()) return Expand;
// If a target-specific SDNode requires legalization, require the target
return (LegalizeAction)OpActions[I][Op];
}
- /// isOperationLegalOrCustom - Return true if the specified operation is
- /// legal on this target or can be made legal with custom lowering. This
- /// is used to help guide high-level lowering decisions.
+ /// Return true if the specified operation is legal on this target or can be
+ /// made legal with custom lowering. This is used to help guide high-level
+ /// lowering decisions.
bool isOperationLegalOrCustom(unsigned Op, EVT VT) const {
return (VT == MVT::Other || isTypeLegal(VT)) &&
(getOperationAction(Op, VT) == Legal ||
getOperationAction(Op, VT) == Custom);
}
- /// isOperationExpand - Return true if the specified operation is illegal on
- /// this target or unlikely to be made legal with custom lowering. This is
- /// used to help guide high-level lowering decisions.
+ /// Return true if the specified operation is legal on this target or can be
+ /// made legal using promotion. This is used to help guide high-level lowering
+ /// decisions.
+ bool isOperationLegalOrPromote(unsigned Op, EVT VT) const {
+ return (VT == MVT::Other || isTypeLegal(VT)) &&
+ (getOperationAction(Op, VT) == Legal ||
+ getOperationAction(Op, VT) == Promote);
+ }
+
+ /// Return true if the specified operation is illegal on this target or
+ /// unlikely to be made legal with custom lowering. This is used to help guide
+ /// high-level lowering decisions.
bool isOperationExpand(unsigned Op, EVT VT) const {
return (!isTypeLegal(VT) || getOperationAction(Op, VT) == Expand);
}
- /// isOperationLegal - Return true if the specified operation is legal on this
- /// target.
+ /// Return true if the specified operation is legal on this target.
bool isOperationLegal(unsigned Op, EVT VT) const {
return (VT == MVT::Other || isTypeLegal(VT)) &&
getOperationAction(Op, VT) == Legal;
}
- /// getLoadExtAction - Return how this load with extension should be treated:
- /// either it is legal, needs to be promoted to a larger size, needs to be
- /// expanded to some other code sequence, or the target has a custom expander
- /// for it.
- LegalizeAction getLoadExtAction(unsigned ExtType, MVT VT) const {
- assert(ExtType < ISD::LAST_LOADEXT_TYPE && VT < MVT::LAST_VALUETYPE &&
+ /// Return how this load with extension should be treated: either it is legal,
+ /// needs to be promoted to a larger size, needs to be expanded to some other
+ /// code sequence, or the target has a custom expander for it.
+ LegalizeAction getLoadExtAction(unsigned ExtType, EVT ValVT, EVT MemVT) const {
+ if (ValVT.isExtended() || MemVT.isExtended()) return Expand;
+ unsigned ValI = (unsigned) ValVT.getSimpleVT().SimpleTy;
+ unsigned MemI = (unsigned) MemVT.getSimpleVT().SimpleTy;
+ assert(ExtType < ISD::LAST_LOADEXT_TYPE && ValI < MVT::LAST_VALUETYPE &&
+ MemI < MVT::LAST_VALUETYPE && "Table isn't big enough!");
+ return (LegalizeAction)LoadExtActions[ValI][MemI][ExtType];
+ }
+
+ /// Return true if the specified load with extension is legal on this target.
+ bool isLoadExtLegal(unsigned ExtType, EVT ValVT, EVT MemVT) const {
+ return ValVT.isSimple() && MemVT.isSimple() &&
+ getLoadExtAction(ExtType, ValVT, MemVT) == Legal;
+ }
+
+ /// Return how this store with truncation should be treated: either it is
+ /// legal, needs to be promoted to a larger size, needs to be expanded to some
+ /// other code sequence, or the target has a custom expander for it.
+ LegalizeAction getTruncStoreAction(EVT ValVT, EVT MemVT) const {
+ if (ValVT.isExtended() || MemVT.isExtended()) return Expand;
+ unsigned ValI = (unsigned) ValVT.getSimpleVT().SimpleTy;
+ unsigned MemI = (unsigned) MemVT.getSimpleVT().SimpleTy;
+ assert(ValI < MVT::LAST_VALUETYPE && MemI < MVT::LAST_VALUETYPE &&
"Table isn't big enough!");
- return (LegalizeAction)LoadExtActions[VT.SimpleTy][ExtType];
+ return (LegalizeAction)TruncStoreActions[ValI][MemI];
}
- /// isLoadExtLegal - Return true if the specified load with extension is legal
- /// on this target.
- bool isLoadExtLegal(unsigned ExtType, EVT VT) const {
- return VT.isSimple() &&
- getLoadExtAction(ExtType, VT.getSimpleVT()) == Legal;
- }
-
- /// getTruncStoreAction - Return how this store with truncation should be
- /// treated: either it is legal, needs to be promoted to a larger size, needs
- /// to be expanded to some other code sequence, or the target has a custom
- /// expander for it.
- LegalizeAction getTruncStoreAction(MVT ValVT, MVT MemVT) const {
- assert(ValVT < MVT::LAST_VALUETYPE && MemVT < MVT::LAST_VALUETYPE &&
- "Table isn't big enough!");
- return (LegalizeAction)TruncStoreActions[ValVT.SimpleTy]
- [MemVT.SimpleTy];
- }
-
- /// isTruncStoreLegal - Return true if the specified store with truncation is
- /// legal on this target.
+ /// Return true if the specified store with truncation is legal on this
+ /// target.
bool isTruncStoreLegal(EVT ValVT, EVT MemVT) const {
return isTypeLegal(ValVT) && MemVT.isSimple() &&
getTruncStoreAction(ValVT.getSimpleVT(), MemVT.getSimpleVT()) == Legal;
}
- /// getIndexedLoadAction - Return how the indexed load should be treated:
- /// either it is legal, needs to be promoted to a larger size, needs to be
- /// expanded to some other code sequence, or the target has a custom expander
- /// for it.
+ /// Return how the indexed load should be treated: either it is legal, needs
+ /// to be promoted to a larger size, needs to be expanded to some other code
+ /// sequence, or the target has a custom expander for it.
LegalizeAction
getIndexedLoadAction(unsigned IdxMode, MVT VT) const {
- assert(IdxMode < ISD::LAST_INDEXED_MODE && VT < MVT::LAST_VALUETYPE &&
+ assert(IdxMode < ISD::LAST_INDEXED_MODE && VT.isValid() &&
"Table isn't big enough!");
unsigned Ty = (unsigned)VT.SimpleTy;
return (LegalizeAction)((IndexedModeActions[Ty][IdxMode] & 0xf0) >> 4);
}
- /// isIndexedLoadLegal - Return true if the specified indexed load is legal
- /// on this target.
+ /// Return true if the specified indexed load is legal on this target.
bool isIndexedLoadLegal(unsigned IdxMode, EVT VT) const {
return VT.isSimple() &&
(getIndexedLoadAction(IdxMode, VT.getSimpleVT()) == Legal ||
getIndexedLoadAction(IdxMode, VT.getSimpleVT()) == Custom);
}
- /// getIndexedStoreAction - Return how the indexed store should be treated:
- /// either it is legal, needs to be promoted to a larger size, needs to be
- /// expanded to some other code sequence, or the target has a custom expander
- /// for it.
+ /// Return how the indexed store should be treated: either it is legal, needs
+ /// to be promoted to a larger size, needs to be expanded to some other code
+ /// sequence, or the target has a custom expander for it.
LegalizeAction
getIndexedStoreAction(unsigned IdxMode, MVT VT) const {
- assert(IdxMode < ISD::LAST_INDEXED_MODE && VT < MVT::LAST_VALUETYPE &&
+ assert(IdxMode < ISD::LAST_INDEXED_MODE && VT.isValid() &&
"Table isn't big enough!");
unsigned Ty = (unsigned)VT.SimpleTy;
return (LegalizeAction)(IndexedModeActions[Ty][IdxMode] & 0x0f);
}
- /// isIndexedStoreLegal - Return true if the specified indexed load is legal
- /// on this target.
+ /// Return true if the specified indexed load is legal on this target.
bool isIndexedStoreLegal(unsigned IdxMode, EVT VT) const {
return VT.isSimple() &&
(getIndexedStoreAction(IdxMode, VT.getSimpleVT()) == Legal ||
getIndexedStoreAction(IdxMode, VT.getSimpleVT()) == Custom);
}
- /// getCondCodeAction - Return how the condition code should be treated:
- /// either it is legal, needs to be expanded to some other code sequence,
- /// or the target has a custom expander for it.
+ /// Return how the condition code should be treated: either it is legal, needs
+ /// to be expanded to some other code sequence, or the target has a custom
+ /// expander for it.
LegalizeAction
getCondCodeAction(ISD::CondCode CC, MVT VT) const {
assert((unsigned)CC < array_lengthof(CondCodeActions) &&
- (unsigned)VT.SimpleTy < sizeof(CondCodeActions[0])*4 &&
+ ((unsigned)VT.SimpleTy >> 4) < array_lengthof(CondCodeActions[0]) &&
"Table isn't big enough!");
- /// The lower 5 bits of the SimpleTy index into Nth 2bit set from the 64bit
- /// value and the upper 27 bits index into the second dimension of the
- /// array to select what 64bit value to use.
- LegalizeAction Action = (LegalizeAction)
- ((CondCodeActions[CC][VT.SimpleTy >> 5] >> (2*(VT.SimpleTy & 0x1F))) & 3);
+ // See setCondCodeAction for how this is encoded.
+ uint32_t Shift = 2 * (VT.SimpleTy & 0xF);
+ uint32_t Value = CondCodeActions[CC][VT.SimpleTy >> 4];
+ LegalizeAction Action = (LegalizeAction) ((Value >> Shift) & 0x3);
assert(Action != Promote && "Can't promote condition code!");
return Action;
}
- /// isCondCodeLegal - Return true if the specified condition code is legal
- /// on this target.
+ /// Return true if the specified condition code is legal on this target.
bool isCondCodeLegal(ISD::CondCode CC, MVT VT) const {
return
getCondCodeAction(CC, VT) == Legal ||
}
- /// getTypeToPromoteTo - If the action for this operation is to promote, this
- /// method returns the ValueType to promote to.
+ /// If the action for this operation is to promote, this method returns the
+ /// ValueType to promote to.
MVT getTypeToPromoteTo(unsigned Op, MVT VT) const {
assert(getOperationAction(Op, VT) == Promote &&
"This operation isn't promoted!");
return NVT;
}
- /// getValueType - Return the EVT corresponding to this LLVM type.
- /// This is fixed by the LLVM operations except for the pointer size. If
- /// AllowUnknown is true, this will return MVT::Other for types with no EVT
- /// counterpart (e.g. structs), otherwise it will assert.
+ /// Return the EVT corresponding to this LLVM type. This is fixed by the LLVM
+ /// operations except for the pointer size. If AllowUnknown is true, this
+ /// will return MVT::Other for types with no EVT counterpart (e.g. structs),
+ /// otherwise it will assert.
EVT getValueType(Type *Ty, bool AllowUnknown = false) const {
// Lower scalar pointers to native pointer types.
- if (Ty->isPointerTy()) return PointerTy;
+ if (PointerType *PTy = dyn_cast<PointerType>(Ty))
+ return getPointerTy(PTy->getAddressSpace());
if (Ty->isVectorTy()) {
VectorType *VTy = cast<VectorType>(Ty);
Type *Elm = VTy->getElementType();
// Lower vectors of pointers to native pointer types.
- if (Elm->isPointerTy())
- Elm = EVT(PointerTy).getTypeForEVT(Ty->getContext());
+ if (PointerType *PT = dyn_cast<PointerType>(Elm)) {
+ EVT PointerTy(getPointerTy(PT->getAddressSpace()));
+ Elm = PointerTy.getTypeForEVT(Ty->getContext());
+ }
+
return EVT::getVectorVT(Ty->getContext(), EVT::getEVT(Elm, false),
VTy->getNumElements());
}
return getValueType(Ty, AllowUnknown).getSimpleVT();
}
- /// getByValTypeAlignment - Return the desired alignment for ByVal aggregate
- /// function arguments in the caller parameter area. This is the actual
- /// alignment, not its logarithm.
+ /// Return the desired alignment for ByVal or InAlloca aggregate function
+ /// arguments in the caller parameter area. This is the actual alignment, not
+ /// its logarithm.
virtual unsigned getByValTypeAlignment(Type *Ty) const;
- /// getRegisterType - Return the type of registers that this ValueType will
- /// eventually require.
+ /// Return the type of registers that this ValueType will eventually require.
MVT getRegisterType(MVT VT) const {
assert((unsigned)VT.SimpleTy < array_lengthof(RegisterTypeForVT));
return RegisterTypeForVT[VT.SimpleTy];
}
- /// getRegisterType - Return the type of registers that this ValueType will
- /// eventually require.
+ /// Return the type of registers that this ValueType will eventually require.
MVT getRegisterType(LLVMContext &Context, EVT VT) const {
if (VT.isSimple()) {
assert((unsigned)VT.getSimpleVT().SimpleTy <
llvm_unreachable("Unsupported extended type!");
}
- /// getNumRegisters - Return the number of registers that this ValueType will
- /// eventually require. This is one for any types promoted to live in larger
- /// registers, but may be more than one for types (like i64) that are split
- /// into pieces. For types like i140, which are first promoted then expanded,
- /// it is the number of registers needed to hold all the bits of the original
- /// type. For an i140 on a 32 bit machine this means 5 registers.
+ /// Return the number of registers that this ValueType will eventually
+ /// require.
+ ///
+ /// This is one for any types promoted to live in larger registers, but may be
+ /// more than one for types (like i64) that are split into pieces. For types
+ /// like i140, which are first promoted then expanded, it is the number of
+ /// registers needed to hold all the bits of the original type. For an i140
+ /// on a 32 bit machine this means 5 registers.
unsigned getNumRegisters(LLVMContext &Context, EVT VT) const {
if (VT.isSimple()) {
assert((unsigned)VT.getSimpleVT().SimpleTy <
llvm_unreachable("Unsupported extended type!");
}
- /// ShouldShrinkFPConstant - If true, then instruction selection should
- /// seek to shrink the FP constant of the specified type to a smaller type
- /// in order to save space and / or reduce runtime.
+ /// If true, then instruction selection should seek to shrink the FP constant
+ /// of the specified type to a smaller type in order to save space and / or
+ /// reduce runtime.
virtual bool ShouldShrinkFPConstant(EVT) const { return true; }
- /// hasTargetDAGCombine - If true, the target has custom DAG combine
- /// transformations that it can perform for the specified node.
+ // Return true if it is profitable to reduce the given load node to a smaller
+ // type.
+ //
+ // e.g. (i16 (trunc (i32 (load x))) -> i16 load x should be performed
+ virtual bool shouldReduceLoadWidth(SDNode *Load,
+ ISD::LoadExtType ExtTy,
+ EVT NewVT) const {
+ return true;
+ }
+
+ /// When splitting a value of the specified type into parts, does the Lo
+ /// or Hi part come first? This usually follows the endianness, except
+ /// for ppcf128, where the Hi part always comes first.
+ bool hasBigEndianPartOrdering(EVT VT) const {
+ return isBigEndian() || VT == MVT::ppcf128;
+ }
+
+ /// If true, the target has custom DAG combine transformations that it can
+ /// perform for the specified node.
bool hasTargetDAGCombine(ISD::NodeType NT) const {
assert(unsigned(NT >> 3) < array_lengthof(TargetDAGCombineArray));
return TargetDAGCombineArray[NT >> 3] & (1 << (NT&7));
}
+ /// \brief Get maximum # of store operations permitted for llvm.memset
+ ///
/// This function returns the maximum number of store operations permitted
/// to replace a call to llvm.memset. The value is set by the target at the
/// performance threshold for such a replacement. If OptSize is true,
/// return the limit for functions that have OptSize attribute.
- /// @brief Get maximum # of store operations permitted for llvm.memset
unsigned getMaxStoresPerMemset(bool OptSize) const {
- return OptSize ? maxStoresPerMemsetOptSize : maxStoresPerMemset;
+ return OptSize ? MaxStoresPerMemsetOptSize : MaxStoresPerMemset;
}
+ /// \brief Get maximum # of store operations permitted for llvm.memcpy
+ ///
/// This function returns the maximum number of store operations permitted
/// to replace a call to llvm.memcpy. The value is set by the target at the
/// performance threshold for such a replacement. If OptSize is true,
/// return the limit for functions that have OptSize attribute.
- /// @brief Get maximum # of store operations permitted for llvm.memcpy
unsigned getMaxStoresPerMemcpy(bool OptSize) const {
- return OptSize ? maxStoresPerMemcpyOptSize : maxStoresPerMemcpy;
+ return OptSize ? MaxStoresPerMemcpyOptSize : MaxStoresPerMemcpy;
}
+ /// \brief Get maximum # of store operations permitted for llvm.memmove
+ ///
/// This function returns the maximum number of store operations permitted
/// to replace a call to llvm.memmove. The value is set by the target at the
/// performance threshold for such a replacement. If OptSize is true,
/// return the limit for functions that have OptSize attribute.
- /// @brief Get maximum # of store operations permitted for llvm.memmove
unsigned getMaxStoresPerMemmove(bool OptSize) const {
- return OptSize ? maxStoresPerMemmoveOptSize : maxStoresPerMemmove;
- }
-
- /// This function returns true if the target allows unaligned memory accesses.
- /// of the specified type. If true, it also returns whether the unaligned
- /// memory access is "fast" in the second argument by reference. This is used,
- /// for example, in situations where an array copy/move/set is converted to a
- /// sequence of store operations. It's use helps to ensure that such
- /// replacements don't generate code that causes an alignment error (trap) on
- /// the target machine.
- /// @brief Determine if the target supports unaligned memory accesses.
- virtual bool allowsUnalignedMemoryAccesses(EVT, bool *Fast = 0) const {
+ return OptSize ? MaxStoresPerMemmoveOptSize : MaxStoresPerMemmove;
+ }
+
+ /// \brief Determine if the target supports unaligned memory accesses.
+ ///
+ /// This function returns true if the target allows unaligned memory accesses
+ /// of the specified type in the given address space. If true, it also returns
+ /// whether the unaligned memory access is "fast" in the last argument by
+ /// reference. This is used, for example, in situations where an array
+ /// copy/move/set is converted to a sequence of store operations. Its use
+ /// helps to ensure that such replacements don't generate code that causes an
+ /// alignment error (trap) on the target machine.
+ virtual bool allowsMisalignedMemoryAccesses(EVT,
+ unsigned AddrSpace = 0,
+ unsigned Align = 1,
+ bool * /*Fast*/ = nullptr) const {
return false;
}
- /// This function returns true if the target would benefit from code placement
- /// optimization.
- /// @brief Determine if the target should perform code placement optimization.
- bool shouldOptimizeCodePlacement() const {
- return benefitFromCodePlacementOpt;
- }
-
- /// getOptimalMemOpType - Returns the target specific optimal type for load
- /// and store operations as a result of memset, memcpy, and memmove
- /// lowering. If DstAlign is zero that means it's safe to destination
- /// alignment can satisfy any constraint. Similarly if SrcAlign is zero it
- /// means there isn't a need to check it against alignment requirement,
- /// probably because the source does not need to be loaded. If 'IsMemset' is
- /// true, that means it's expanding a memset. If 'ZeroMemset' is true, that
- /// means it's a memset of zero. 'MemcpyStrSrc' indicates whether the memcpy
- /// source is constant so it does not need to be loaded.
- /// It returns EVT::Other if the type should be determined using generic
- /// target-independent logic.
+ /// Returns the target specific optimal type for load and store operations as
+ /// a result of memset, memcpy, and memmove lowering.
+ ///
+ /// If DstAlign is zero that means it's safe to destination alignment can
+ /// satisfy any constraint. Similarly if SrcAlign is zero it means there isn't
+ /// a need to check it against alignment requirement, probably because the
+ /// source does not need to be loaded. If 'IsMemset' is true, that means it's
+ /// expanding a memset. If 'ZeroMemset' is true, that means it's a memset of
+ /// zero. 'MemcpyStrSrc' indicates whether the memcpy source is constant so it
+ /// does not need to be loaded. It returns EVT::Other if the type should be
+ /// determined using generic target-independent logic.
virtual EVT getOptimalMemOpType(uint64_t /*Size*/,
unsigned /*DstAlign*/, unsigned /*SrcAlign*/,
bool /*IsMemset*/,
return MVT::Other;
}
- /// isSafeMemOpType - Returns true if it's safe to use load / store of the
- /// specified type to expand memcpy / memset inline. This is mostly true
- /// for all types except for some special cases. For example, on X86
- /// targets without SSE2 f64 load / store are done with fldl / fstpl which
- /// also does type conversion. Note the specified type doesn't have to be
- /// legal as the hook is used before type legalization.
- virtual bool isSafeMemOpType(MVT VT) const {
- return true;
- }
+ /// Returns true if it's safe to use load / store of the specified type to
+ /// expand memcpy / memset inline.
+ ///
+ /// This is mostly true for all types except for some special cases. For
+ /// example, on X86 targets without SSE2 f64 load / store are done with fldl /
+ /// fstpl which also does type conversion. Note the specified type doesn't
+ /// have to be legal as the hook is used before type legalization.
+ virtual bool isSafeMemOpType(MVT /*VT*/) const { return true; }
- /// usesUnderscoreSetJmp - Determine if we should use _setjmp or setjmp
- /// to implement llvm.setjmp.
+ /// Determine if we should use _setjmp or setjmp to implement llvm.setjmp.
bool usesUnderscoreSetJmp() const {
return UseUnderscoreSetJmp;
}
- /// usesUnderscoreLongJmp - Determine if we should use _longjmp or longjmp
- /// to implement llvm.longjmp.
+ /// Determine if we should use _longjmp or longjmp to implement llvm.longjmp.
bool usesUnderscoreLongJmp() const {
return UseUnderscoreLongJmp;
}
- /// supportJumpTables - return whether the target can generate code for
- /// jump tables.
- bool supportJumpTables() const {
- return SupportJumpTables;
- }
-
- /// getMinimumJumpTableEntries - return integer threshold on number of
- /// blocks to use jump tables rather than if sequence.
+ /// Return integer threshold on number of blocks to use jump tables rather
+ /// than if sequence.
int getMinimumJumpTableEntries() const {
return MinimumJumpTableEntries;
}
- /// getStackPointerRegisterToSaveRestore - If a physical register, this
- /// specifies the register that llvm.savestack/llvm.restorestack should save
- /// and restore.
+ /// If a physical register, this specifies the register that
+ /// llvm.savestack/llvm.restorestack should save and restore.
unsigned getStackPointerRegisterToSaveRestore() const {
return StackPointerRegisterToSaveRestore;
}
- /// getExceptionPointerRegister - If a physical register, this returns
- /// the register that receives the exception address on entry to a landing
- /// pad.
+ /// If a physical register, this returns the register that receives the
+ /// exception address on entry to a landing pad.
unsigned getExceptionPointerRegister() const {
return ExceptionPointerRegister;
}
- /// getExceptionSelectorRegister - If a physical register, this returns
- /// the register that receives the exception typeid on entry to a landing
- /// pad.
+ /// If a physical register, this returns the register that receives the
+ /// exception typeid on entry to a landing pad.
unsigned getExceptionSelectorRegister() const {
return ExceptionSelectorRegister;
}
- /// getJumpBufSize - returns the target's jmp_buf size in bytes (if never
- /// set, the default is 200)
+ /// Returns the target's jmp_buf size in bytes (if never set, the default is
+ /// 200)
unsigned getJumpBufSize() const {
return JumpBufSize;
}
- /// getJumpBufAlignment - returns the target's jmp_buf alignment in bytes
- /// (if never set, the default is 0)
+ /// Returns the target's jmp_buf alignment in bytes (if never set, the default
+ /// is 0)
unsigned getJumpBufAlignment() const {
return JumpBufAlignment;
}
- /// getMinStackArgumentAlignment - return the minimum stack alignment of an
- /// argument.
+ /// Return the minimum stack alignment of an argument.
unsigned getMinStackArgumentAlignment() const {
return MinStackArgumentAlignment;
}
- /// getMinFunctionAlignment - return the minimum function alignment.
- ///
+ /// Return the minimum function alignment.
unsigned getMinFunctionAlignment() const {
return MinFunctionAlignment;
}
- /// getPrefFunctionAlignment - return the preferred function alignment.
- ///
+ /// Return the preferred function alignment.
unsigned getPrefFunctionAlignment() const {
return PrefFunctionAlignment;
}
- /// getPrefLoopAlignment - return the preferred loop alignment.
- ///
- unsigned getPrefLoopAlignment() const {
+ /// Return the preferred loop alignment.
+ virtual unsigned getPrefLoopAlignment(MachineLoop *ML = nullptr) const {
return PrefLoopAlignment;
}
- /// getShouldFoldAtomicFences - return whether the combiner should fold
- /// fence MEMBARRIER instructions into the atomic intrinsic instructions.
- ///
- bool getShouldFoldAtomicFences() const {
- return ShouldFoldAtomicFences;
- }
-
- /// getInsertFencesFor - return whether the DAG builder should automatically
- /// insert fences and reduce ordering for atomics.
- ///
+ /// Return whether the DAG builder should automatically insert fences and
+ /// reduce ordering for atomics.
bool getInsertFencesForAtomic() const {
return InsertFencesForAtomic;
}
- /// getPreIndexedAddressParts - returns true by value, base pointer and
- /// offset pointer and addressing mode by reference if the node's address
- /// can be legally represented as pre-indexed load / store address.
- virtual bool getPreIndexedAddressParts(SDNode * /*N*/, SDValue &/*Base*/,
- SDValue &/*Offset*/,
- ISD::MemIndexedMode &/*AM*/,
- SelectionDAG &/*DAG*/) const {
- return false;
- }
-
- /// getPostIndexedAddressParts - returns true by value, base pointer and
- /// offset pointer and addressing mode by reference if this node can be
- /// combined with a load / store to form a post-indexed load / store.
- virtual bool getPostIndexedAddressParts(SDNode * /*N*/, SDNode * /*Op*/,
- SDValue &/*Base*/, SDValue &/*Offset*/,
- ISD::MemIndexedMode &/*AM*/,
- SelectionDAG &/*DAG*/) const {
- return false;
- }
-
- /// getJumpTableEncoding - Return the entry encoding for a jump table in the
- /// current function. The returned value is a member of the
- /// MachineJumpTableInfo::JTEntryKind enum.
- virtual unsigned getJumpTableEncoding() const;
-
- virtual const MCExpr *
- LowerCustomJumpTableEntry(const MachineJumpTableInfo * /*MJTI*/,
- const MachineBasicBlock * /*MBB*/, unsigned /*uid*/,
- MCContext &/*Ctx*/) const {
- llvm_unreachable("Need to implement this hook if target has custom JTIs");
- }
-
- /// getPICJumpTableRelocaBase - Returns relocation base for the given PIC
- /// jumptable.
- virtual SDValue getPICJumpTableRelocBase(SDValue Table,
- SelectionDAG &DAG) const;
-
- /// getPICJumpTableRelocBaseExpr - This returns the relocation base for the
- /// given PIC jumptable, the same as getPICJumpTableRelocBase, but as an
- /// MCExpr.
- virtual const MCExpr *
- getPICJumpTableRelocBaseExpr(const MachineFunction *MF,
- unsigned JTI, MCContext &Ctx) const;
-
- /// isOffsetFoldingLegal - Return true if folding a constant offset
- /// with the given GlobalAddress is legal. It is frequently not legal in
- /// PIC relocation models.
- virtual bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const;
-
- /// getStackCookieLocation - Return true if the target stores stack
- /// protector cookies at a fixed offset in some non-standard address
- /// space, and populates the address space and offset as
- /// appropriate.
+ /// Return true if the target stores stack protector cookies at a fixed offset
+ /// in some non-standard address space, and populates the address space and
+ /// offset as appropriate.
virtual bool getStackCookieLocation(unsigned &/*AddressSpace*/,
unsigned &/*Offset*/) const {
return false;
}
- /// getMaximalGlobalOffset - Returns the maximal possible offset which can be
- /// used for loads / stores from the global.
+ /// Returns the maximal possible offset which can be used for loads / stores
+ /// from the global.
virtual unsigned getMaximalGlobalOffset() const {
return 0;
}
- //===--------------------------------------------------------------------===//
- // TargetLowering Optimization Methods
- //
-
- /// TargetLoweringOpt - A convenience struct that encapsulates a DAG, and two
- /// SDValues for returning information from TargetLowering to its clients
- /// that want to combine
- struct TargetLoweringOpt {
- SelectionDAG &DAG;
- bool LegalTys;
- bool LegalOps;
- SDValue Old;
- SDValue New;
-
- explicit TargetLoweringOpt(SelectionDAG &InDAG,
- bool LT, bool LO) :
- DAG(InDAG), LegalTys(LT), LegalOps(LO) {}
-
- bool LegalTypes() const { return LegalTys; }
- bool LegalOperations() const { return LegalOps; }
-
- bool CombineTo(SDValue O, SDValue N) {
- Old = O;
- New = N;
- return true;
- }
-
- /// ShrinkDemandedConstant - Check to see if the specified operand of the
- /// specified instruction is a constant integer. If so, check to see if
- /// there are any bits set in the constant that are not demanded. If so,
- /// shrink the constant and return true.
- bool ShrinkDemandedConstant(SDValue Op, const APInt &Demanded);
-
- /// ShrinkDemandedOp - Convert x+y to (VT)((SmallVT)x+(SmallVT)y) if the
- /// casts are free. This uses isZExtFree and ZERO_EXTEND for the widening
- /// cast, but it could be generalized for targets with other types of
- /// implicit widening casts.
- bool ShrinkDemandedOp(SDValue Op, unsigned BitWidth, const APInt &Demanded,
- DebugLoc dl);
- };
-
- /// SimplifyDemandedBits - Look at Op. At this point, we know that only the
- /// DemandedMask bits of the result of Op are ever used downstream. If we can
- /// use this information to simplify Op, create a new simplified DAG node and
- /// return true, returning the original and new nodes in Old and New.
- /// Otherwise, analyze the expression and return a mask of KnownOne and
- /// KnownZero bits for the expression (used to simplify the caller).
- /// The KnownZero/One bits may only be accurate for those bits in the
- /// DemandedMask.
- bool SimplifyDemandedBits(SDValue Op, const APInt &DemandedMask,
- APInt &KnownZero, APInt &KnownOne,
- TargetLoweringOpt &TLO, unsigned Depth = 0) const;
-
- /// computeMaskedBitsForTargetNode - Determine which of the bits specified in
- /// Mask are known to be either zero or one and return them in the
- /// KnownZero/KnownOne bitsets.
- virtual void computeMaskedBitsForTargetNode(const SDValue Op,
- APInt &KnownZero,
- APInt &KnownOne,
- const SelectionDAG &DAG,
- unsigned Depth = 0) const;
-
- /// ComputeNumSignBitsForTargetNode - This method can be implemented by
- /// targets that want to expose additional information about sign bits to the
- /// DAG Combiner.
- virtual unsigned ComputeNumSignBitsForTargetNode(SDValue Op,
- unsigned Depth = 0) const;
-
- struct DAGCombinerInfo {
- void *DC; // The DAG Combiner object.
- bool BeforeLegalize;
- bool BeforeLegalizeOps;
- bool CalledByLegalizer;
- public:
- SelectionDAG &DAG;
-
- DAGCombinerInfo(SelectionDAG &dag, bool bl, bool blo, bool cl, void *dc)
- : DC(dc), BeforeLegalize(bl), BeforeLegalizeOps(blo),
- CalledByLegalizer(cl), DAG(dag) {}
-
- bool isBeforeLegalize() const { return BeforeLegalize; }
- bool isBeforeLegalizeOps() const { return BeforeLegalizeOps; }
- bool isCalledByLegalizer() const { return CalledByLegalizer; }
-
- void AddToWorklist(SDNode *N);
- void RemoveFromWorklist(SDNode *N);
- SDValue CombineTo(SDNode *N, const std::vector<SDValue> &To,
- bool AddTo = true);
- SDValue CombineTo(SDNode *N, SDValue Res, bool AddTo = true);
- SDValue CombineTo(SDNode *N, SDValue Res0, SDValue Res1, bool AddTo = true);
-
- void CommitTargetLoweringOpt(const TargetLoweringOpt &TLO);
- };
+ /// Returns true if a cast between SrcAS and DestAS is a noop.
+ virtual bool isNoopAddrSpaceCast(unsigned SrcAS, unsigned DestAS) const {
+ return false;
+ }
- /// SimplifySetCC - Try to simplify a setcc built with the specified operands
- /// and cc. If it is unable to simplify it, return a null SDValue.
- SDValue SimplifySetCC(EVT VT, SDValue N0, SDValue N1,
- ISD::CondCode Cond, bool foldBooleans,
- DAGCombinerInfo &DCI, DebugLoc dl) const;
+ //===--------------------------------------------------------------------===//
+ /// \name Helpers for TargetTransformInfo implementations
+ /// @{
- /// isGAPlusOffset - Returns true (and the GlobalValue and the offset) if the
- /// node is a GlobalAddress + offset.
- virtual bool
- isGAPlusOffset(SDNode *N, const GlobalValue* &GA, int64_t &Offset) const;
+ /// Get the ISD node that corresponds to the Instruction class opcode.
+ int InstructionOpcodeToISD(unsigned Opcode) const;
- /// PerformDAGCombine - This method will be invoked for all target nodes and
- /// for any target-independent nodes that the target has registered with
- /// invoke it for.
- ///
- /// The semantics are as follows:
- /// Return Value:
- /// SDValue.Val == 0 - No change was made
- /// SDValue.Val == N - N was replaced, is dead, and is already handled.
- /// otherwise - N should be replaced by the returned Operand.
- ///
- /// In addition, methods provided by DAGCombinerInfo may be used to perform
- /// more complex transformations.
- ///
- virtual SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const;
+ /// Estimate the cost of type-legalization and the legalized type.
+ std::pair<unsigned, MVT> getTypeLegalizationCost(Type *Ty) const;
- /// isTypeDesirableForOp - Return true if the target has native support for
- /// the specified value type and it is 'desirable' to use the type for the
- /// given node type. e.g. On x86 i16 is legal, but undesirable since i16
- /// instruction encodings are longer and some i16 instructions are slow.
- virtual bool isTypeDesirableForOp(unsigned /*Opc*/, EVT VT) const {
- // By default, assume all legal types are desirable.
- return isTypeLegal(VT);
- }
+ /// @}
- /// isDesirableToPromoteOp - Return true if it is profitable for dag combiner
- /// to transform a floating point op of specified opcode to a equivalent op of
- /// an integer type. e.g. f32 load -> i32 load can be profitable on ARM.
- virtual bool isDesirableToTransformToIntegerOp(unsigned /*Opc*/,
- EVT /*VT*/) const {
+ //===--------------------------------------------------------------------===//
+ /// \name Helpers for atomic expansion.
+ /// @{
+
+ /// True if AtomicExpandPass should use emitLoadLinked/emitStoreConditional
+ /// and expand AtomicCmpXchgInst.
+ virtual bool hasLoadLinkedStoreConditional() const { return false; }
+
+ /// Perform a load-linked operation on Addr, returning a "Value *" with the
+ /// corresponding pointee type. This may entail some non-trivial operations to
+ /// truncate or reconstruct types that will be illegal in the backend. See
+ /// ARMISelLowering for an example implementation.
+ virtual Value *emitLoadLinked(IRBuilder<> &Builder, Value *Addr,
+ AtomicOrdering Ord) const {
+ llvm_unreachable("Load linked unimplemented on this target");
+ }
+
+ /// Perform a store-conditional operation to Addr. Return the status of the
+ /// store. This should be 0 if the store succeeded, non-zero otherwise.
+ virtual Value *emitStoreConditional(IRBuilder<> &Builder, Value *Val,
+ Value *Addr, AtomicOrdering Ord) const {
+ llvm_unreachable("Store conditional unimplemented on this target");
+ }
+
+ /// Inserts in the IR a target-specific intrinsic specifying a fence.
+ /// It is called by AtomicExpandPass before expanding an
+ /// AtomicRMW/AtomicCmpXchg/AtomicStore/AtomicLoad.
+ /// RMW and CmpXchg set both IsStore and IsLoad to true.
+ /// This function should either return a nullptr, or a pointer to an IR-level
+ /// Instruction*. Even complex fence sequences can be represented by a
+ /// single Instruction* through an intrinsic to be lowered later.
+ /// Backends with !getInsertFencesForAtomic() should keep a no-op here.
+ /// Backends should override this method to produce target-specific intrinsic
+ /// for their fences.
+ /// FIXME: Please note that the default implementation here in terms of
+ /// IR-level fences exists for historical/compatibility reasons and is
+ /// *unsound* ! Fences cannot, in general, be used to restore sequential
+ /// consistency. For example, consider the following example:
+ /// atomic<int> x = y = 0;
+ /// int r1, r2, r3, r4;
+ /// Thread 0:
+ /// x.store(1);
+ /// Thread 1:
+ /// y.store(1);
+ /// Thread 2:
+ /// r1 = x.load();
+ /// r2 = y.load();
+ /// Thread 3:
+ /// r3 = y.load();
+ /// r4 = x.load();
+ /// r1 = r3 = 1 and r2 = r4 = 0 is impossible as long as the accesses are all
+ /// seq_cst. But if they are lowered to monotonic accesses, no amount of
+ /// IR-level fences can prevent it.
+ /// @{
+ virtual Instruction* emitLeadingFence(IRBuilder<> &Builder, AtomicOrdering Ord,
+ bool IsStore, bool IsLoad) const {
+ if (!getInsertFencesForAtomic())
+ return nullptr;
+
+ if (isAtLeastRelease(Ord) && IsStore)
+ return Builder.CreateFence(Ord);
+ else
+ return nullptr;
+ }
+
+ virtual Instruction* emitTrailingFence(IRBuilder<> &Builder, AtomicOrdering Ord,
+ bool IsStore, bool IsLoad) const {
+ if (!getInsertFencesForAtomic())
+ return nullptr;
+
+ if (isAtLeastAcquire(Ord))
+ return Builder.CreateFence(Ord);
+ else
+ return nullptr;
+ }
+ /// @}
+
+ /// Returns true if the given (atomic) store should be expanded by the
+ /// IR-level AtomicExpand pass into an "atomic xchg" which ignores its input.
+ virtual bool shouldExpandAtomicStoreInIR(StoreInst *SI) const {
return false;
}
- /// IsDesirableToPromoteOp - This method query the target whether it is
- /// beneficial for dag combiner to promote the specified node. If true, it
- /// should return the desired promotion type by reference.
- virtual bool IsDesirableToPromoteOp(SDValue /*Op*/, EVT &/*PVT*/) const {
+ /// Returns true if the given (atomic) load should be expanded by the
+ /// IR-level AtomicExpand pass into a load-linked instruction
+ /// (through emitLoadLinked()).
+ virtual bool shouldExpandAtomicLoadInIR(LoadInst *LI) const { return false; }
+
+ /// Returns true if the given AtomicRMW should be expanded by the
+ /// IR-level AtomicExpand pass into a loop using LoadLinked/StoreConditional.
+ virtual bool shouldExpandAtomicRMWInIR(AtomicRMWInst *RMWI) const {
return false;
}
+ /// On some platforms, an AtomicRMW that never actually modifies the value
+ /// (such as fetch_add of 0) can be turned into a fence followed by an
+ /// atomic load. This may sound useless, but it makes it possible for the
+ /// processor to keep the cacheline shared, dramatically improving
+ /// performance. And such idempotent RMWs are useful for implementing some
+ /// kinds of locks, see for example (justification + benchmarks):
+ /// http://www.hpl.hp.com/techreports/2012/HPL-2012-68.pdf
+ /// This method tries doing that transformation, returning the atomic load if
+ /// it succeeds, and nullptr otherwise.
+ /// If shouldExpandAtomicLoadInIR returns true on that load, it will undergo
+ /// another round of expansion.
+ virtual LoadInst *lowerIdempotentRMWIntoFencedLoad(AtomicRMWInst *RMWI) const {
+ return nullptr;
+ }
//===--------------------------------------------------------------------===//
// TargetLowering Configuration Methods - These methods should be invoked by
// the derived class constructor to configure this object for the target.
//
+ /// \brief Reset the operation actions based on target options.
+ virtual void resetOperationActions() {}
+
protected:
- /// setBooleanContents - Specify how the target extends the result of a
- /// boolean value from i1 to a wider type. See getBooleanContents.
- void setBooleanContents(BooleanContent Ty) { BooleanContents = Ty; }
- /// setBooleanVectorContents - Specify how the target extends the result
- /// of a vector boolean value from a vector of i1 to a wider type. See
- /// getBooleanContents.
+ /// Specify how the target extends the result of integer and floating point
+ /// boolean values from i1 to a wider type. See getBooleanContents.
+ void setBooleanContents(BooleanContent Ty) {
+ BooleanContents = Ty;
+ BooleanFloatContents = Ty;
+ }
+
+ /// Specify how the target extends the result of integer and floating point
+ /// boolean values from i1 to a wider type. See getBooleanContents.
+ void setBooleanContents(BooleanContent IntTy, BooleanContent FloatTy) {
+ BooleanContents = IntTy;
+ BooleanFloatContents = FloatTy;
+ }
+
+ /// Specify how the target extends the result of a vector boolean value from a
+ /// vector of i1 to a wider type. See getBooleanContents.
void setBooleanVectorContents(BooleanContent Ty) {
BooleanVectorContents = Ty;
}
- /// setSchedulingPreference - Specify the target scheduling preference.
+ /// Specify the target scheduling preference.
void setSchedulingPreference(Sched::Preference Pref) {
SchedPreferenceInfo = Pref;
}
- /// setUseUnderscoreSetJmp - Indicate whether this target prefers to
- /// use _setjmp to implement llvm.setjmp or the non _ version.
- /// Defaults to false.
+ /// Indicate whether this target prefers to use _setjmp to implement
+ /// llvm.setjmp or the version without _. Defaults to false.
void setUseUnderscoreSetJmp(bool Val) {
UseUnderscoreSetJmp = Val;
}
- /// setUseUnderscoreLongJmp - Indicate whether this target prefers to
- /// use _longjmp to implement llvm.longjmp or the non _ version.
- /// Defaults to false.
+ /// Indicate whether this target prefers to use _longjmp to implement
+ /// llvm.longjmp or the version without _. Defaults to false.
void setUseUnderscoreLongJmp(bool Val) {
UseUnderscoreLongJmp = Val;
}
- /// setSupportJumpTables - Indicate whether the target can generate code for
- /// jump tables.
- void setSupportJumpTables(bool Val) {
- SupportJumpTables = Val;
- }
-
- /// setMinimumJumpTableEntries - Indicate the number of blocks to generate
- /// jump tables rather than if sequence.
+ /// Indicate the number of blocks to generate jump tables rather than if
+ /// sequence.
void setMinimumJumpTableEntries(int Val) {
MinimumJumpTableEntries = Val;
}
- /// setStackPointerRegisterToSaveRestore - If set to a physical register, this
- /// specifies the register that llvm.savestack/llvm.restorestack should save
- /// and restore.
+ /// If set to a physical register, this specifies the register that
+ /// llvm.savestack/llvm.restorestack should save and restore.
void setStackPointerRegisterToSaveRestore(unsigned R) {
StackPointerRegisterToSaveRestore = R;
}
- /// setExceptionPointerRegister - If set to a physical register, this sets
- /// the register that receives the exception address on entry to a landing
- /// pad.
+ /// If set to a physical register, this sets the register that receives the
+ /// exception address on entry to a landing pad.
void setExceptionPointerRegister(unsigned R) {
ExceptionPointerRegister = R;
}
- /// setExceptionSelectorRegister - If set to a physical register, this sets
- /// the register that receives the exception typeid on entry to a landing
- /// pad.
+ /// If set to a physical register, this sets the register that receives the
+ /// exception typeid on entry to a landing pad.
void setExceptionSelectorRegister(unsigned R) {
ExceptionSelectorRegister = R;
}
- /// SelectIsExpensive - Tells the code generator not to expand operations
- /// into sequences that use the select operations if possible.
+ /// Tells the code generator not to expand operations into sequences that use
+ /// the select operations if possible.
void setSelectIsExpensive(bool isExpensive = true) {
SelectIsExpensive = isExpensive;
}
- /// JumpIsExpensive - Tells the code generator not to expand sequence of
- /// operations into a separate sequences that increases the amount of
- /// flow control.
+ /// Tells the code generator that the target has multiple (allocatable)
+ /// condition registers that can be used to store the results of comparisons
+ /// for use by selects and conditional branches. With multiple condition
+ /// registers, the code generator will not aggressively sink comparisons into
+ /// the blocks of their users.
+ void setHasMultipleConditionRegisters(bool hasManyRegs = true) {
+ HasMultipleConditionRegisters = hasManyRegs;
+ }
+
+ /// Tells the code generator that the target has BitExtract instructions.
+ /// The code generator will aggressively sink "shift"s into the blocks of
+ /// their users if the users will generate "and" instructions which can be
+ /// combined with "shift" to BitExtract instructions.
+ void setHasExtractBitsInsn(bool hasExtractInsn = true) {
+ HasExtractBitsInsn = hasExtractInsn;
+ }
+
+ /// Tells the code generator not to expand sequence of operations into a
+ /// separate sequences that increases the amount of flow control.
void setJumpIsExpensive(bool isExpensive = true) {
JumpIsExpensive = isExpensive;
}
- /// setIntDivIsCheap - Tells the code generator that integer divide is
- /// expensive, and if possible, should be replaced by an alternate sequence
- /// of instructions not containing an integer divide.
+ /// Tells the code generator that integer divide is expensive, and if
+ /// possible, should be replaced by an alternate sequence of instructions not
+ /// containing an integer divide.
void setIntDivIsCheap(bool isCheap = true) { IntDivIsCheap = isCheap; }
- /// addBypassSlowDiv - Tells the code generator which bitwidths to bypass.
+ /// Tells the code generator that fsqrt is cheap, and should not be replaced
+ /// with an alternative sequence of instructions.
+ void setFsqrtIsCheap(bool isCheap = true) { FsqrtIsCheap = isCheap; }
+
+ /// Tells the code generator that this target supports floating point
+ /// exceptions and cares about preserving floating point exception behavior.
+ void setHasFloatingPointExceptions(bool FPExceptions = true) {
+ HasFloatingPointExceptions = FPExceptions;
+ }
+
+ /// Tells the code generator which bitwidths to bypass.
void addBypassSlowDiv(unsigned int SlowBitWidth, unsigned int FastBitWidth) {
BypassSlowDivWidths[SlowBitWidth] = FastBitWidth;
}
- /// setPow2DivIsCheap - Tells the code generator that it shouldn't generate
- /// srl/add/sra for a signed divide by power of two, and let the target handle
- /// it.
- void setPow2DivIsCheap(bool isCheap = true) { Pow2DivIsCheap = isCheap; }
+ /// Tells the code generator that it shouldn't generate sra/srl/add/sra for a
+ /// signed divide by power of two; let the target handle it.
+ void setPow2SDivIsCheap(bool isCheap = true) { Pow2SDivIsCheap = isCheap; }
- /// addRegisterClass - Add the specified register class as an available
- /// regclass for the specified value type. This indicates the selector can
- /// handle values of that class natively.
+ /// Add the specified register class as an available regclass for the
+ /// specified value type. This indicates the selector can handle values of
+ /// that class natively.
void addRegisterClass(MVT VT, const TargetRegisterClass *RC) {
assert((unsigned)VT.SimpleTy < array_lengthof(RegClassForVT));
AvailableRegClasses.push_back(std::make_pair(VT, RC));
RegClassForVT[VT.SimpleTy] = RC;
}
- /// findRepresentativeClass - Return the largest legal super-reg register class
- /// of the register class for the specified type and its associated "cost".
+ /// Remove all register classes.
+ void clearRegisterClasses() {
+ memset(RegClassForVT, 0,MVT::LAST_VALUETYPE * sizeof(TargetRegisterClass*));
+
+ AvailableRegClasses.clear();
+ }
+
+ /// \brief Remove all operation actions.
+ void clearOperationActions() {
+ }
+
+ /// Return the largest legal super-reg register class of the register class
+ /// for the specified type and its associated "cost".
virtual std::pair<const TargetRegisterClass*, uint8_t>
findRepresentativeClass(MVT VT) const;
- /// computeRegisterProperties - Once all of the register classes are added,
- /// this allows us to compute derived properties we expose.
+ /// Once all of the register classes are added, this allows us to compute
+ /// derived properties we expose.
void computeRegisterProperties();
- /// setOperationAction - Indicate that the specified operation does not work
- /// with the specified type and indicate what to do about it.
+ /// Indicate that the specified operation does not work with the specified
+ /// type and indicate what to do about it.
void setOperationAction(unsigned Op, MVT VT,
LegalizeAction Action) {
assert(Op < array_lengthof(OpActions[0]) && "Table isn't big enough!");
OpActions[(unsigned)VT.SimpleTy][Op] = (uint8_t)Action;
}
- /// setLoadExtAction - Indicate that the specified load with extension does
- /// not work with the specified type and indicate what to do about it.
- void setLoadExtAction(unsigned ExtType, MVT VT,
+ /// Indicate that the specified load with extension does not work with the
+ /// specified type and indicate what to do about it.
+ void setLoadExtAction(unsigned ExtType, MVT ValVT, MVT MemVT,
LegalizeAction Action) {
- assert(ExtType < ISD::LAST_LOADEXT_TYPE && VT < MVT::LAST_VALUETYPE &&
- "Table isn't big enough!");
- LoadExtActions[VT.SimpleTy][ExtType] = (uint8_t)Action;
+ assert(ExtType < ISD::LAST_LOADEXT_TYPE && ValVT.isValid() &&
+ MemVT.isValid() && "Table isn't big enough!");
+ LoadExtActions[ValVT.SimpleTy][MemVT.SimpleTy][ExtType] = (uint8_t)Action;
}
- /// setTruncStoreAction - Indicate that the specified truncating store does
- /// not work with the specified type and indicate what to do about it.
+ /// Indicate that the specified truncating store does not work with the
+ /// specified type and indicate what to do about it.
void setTruncStoreAction(MVT ValVT, MVT MemVT,
LegalizeAction Action) {
- assert(ValVT < MVT::LAST_VALUETYPE && MemVT < MVT::LAST_VALUETYPE &&
- "Table isn't big enough!");
+ assert(ValVT.isValid() && MemVT.isValid() && "Table isn't big enough!");
TruncStoreActions[ValVT.SimpleTy][MemVT.SimpleTy] = (uint8_t)Action;
}
- /// setIndexedLoadAction - Indicate that the specified indexed load does or
- /// does not work with the specified type and indicate what to do abort
- /// it. NOTE: All indexed mode loads are initialized to Expand in
+ /// Indicate that the specified indexed load does or does not work with the
+ /// specified type and indicate what to do abort it.
+ ///
+ /// NOTE: All indexed mode loads are initialized to Expand in
/// TargetLowering.cpp
void setIndexedLoadAction(unsigned IdxMode, MVT VT,
LegalizeAction Action) {
- assert(VT < MVT::LAST_VALUETYPE && IdxMode < ISD::LAST_INDEXED_MODE &&
+ assert(VT.isValid() && IdxMode < ISD::LAST_INDEXED_MODE &&
(unsigned)Action < 0xf && "Table isn't big enough!");
// Load action are kept in the upper half.
IndexedModeActions[(unsigned)VT.SimpleTy][IdxMode] &= ~0xf0;
IndexedModeActions[(unsigned)VT.SimpleTy][IdxMode] |= ((uint8_t)Action) <<4;
}
- /// setIndexedStoreAction - Indicate that the specified indexed store does or
- /// does not work with the specified type and indicate what to do about
- /// it. NOTE: All indexed mode stores are initialized to Expand in
+ /// Indicate that the specified indexed store does or does not work with the
+ /// specified type and indicate what to do about it.
+ ///
+ /// NOTE: All indexed mode stores are initialized to Expand in
/// TargetLowering.cpp
void setIndexedStoreAction(unsigned IdxMode, MVT VT,
LegalizeAction Action) {
- assert(VT < MVT::LAST_VALUETYPE && IdxMode < ISD::LAST_INDEXED_MODE &&
+ assert(VT.isValid() && IdxMode < ISD::LAST_INDEXED_MODE &&
(unsigned)Action < 0xf && "Table isn't big enough!");
// Store action are kept in the lower half.
IndexedModeActions[(unsigned)VT.SimpleTy][IdxMode] &= ~0x0f;
IndexedModeActions[(unsigned)VT.SimpleTy][IdxMode] |= ((uint8_t)Action);
}
- /// setCondCodeAction - Indicate that the specified condition code is or isn't
- /// supported on the target and indicate what to do about it.
+ /// Indicate that the specified condition code is or isn't supported on the
+ /// target and indicate what to do about it.
void setCondCodeAction(ISD::CondCode CC, MVT VT,
LegalizeAction Action) {
- assert(VT < MVT::LAST_VALUETYPE &&
- (unsigned)CC < array_lengthof(CondCodeActions) &&
+ assert(VT.isValid() && (unsigned)CC < array_lengthof(CondCodeActions) &&
"Table isn't big enough!");
- /// The lower 5 bits of the SimpleTy index into Nth 2bit set from the 64bit
- /// value and the upper 27 bits index into the second dimension of the
- /// array to select what 64bit value to use.
- CondCodeActions[(unsigned)CC][VT.SimpleTy >> 5]
- &= ~(uint64_t(3UL) << (VT.SimpleTy & 0x1F)*2);
- CondCodeActions[(unsigned)CC][VT.SimpleTy >> 5]
- |= (uint64_t)Action << (VT.SimpleTy & 0x1F)*2;
- }
-
- /// AddPromotedToType - If Opc/OrigVT is specified as being promoted, the
- /// promotion code defaults to trying a larger integer/fp until it can find
- /// one that works. If that default is insufficient, this method can be used
- /// by the target to override the default.
+ /// The lower 5 bits of the SimpleTy index into Nth 2bit set from the 32-bit
+ /// value and the upper 27 bits index into the second dimension of the array
+ /// to select what 32-bit value to use.
+ uint32_t Shift = 2 * (VT.SimpleTy & 0xF);
+ CondCodeActions[CC][VT.SimpleTy >> 4] &= ~((uint32_t)0x3 << Shift);
+ CondCodeActions[CC][VT.SimpleTy >> 4] |= (uint32_t)Action << Shift;
+ }
+
+ /// If Opc/OrigVT is specified as being promoted, the promotion code defaults
+ /// to trying a larger integer/fp until it can find one that works. If that
+ /// default is insufficient, this method can be used by the target to override
+ /// the default.
void AddPromotedToType(unsigned Opc, MVT OrigVT, MVT DestVT) {
PromoteToType[std::make_pair(Opc, OrigVT.SimpleTy)] = DestVT.SimpleTy;
}
- /// setTargetDAGCombine - Targets should invoke this method for each target
- /// independent node that they want to provide a custom DAG combiner for by
- /// implementing the PerformDAGCombine virtual method.
+ /// Targets should invoke this method for each target independent node that
+ /// they want to provide a custom DAG combiner for by implementing the
+ /// PerformDAGCombine virtual method.
void setTargetDAGCombine(ISD::NodeType NT) {
assert(unsigned(NT >> 3) < array_lengthof(TargetDAGCombineArray));
TargetDAGCombineArray[NT >> 3] |= 1 << (NT&7);
}
- /// setJumpBufSize - Set the target's required jmp_buf buffer size (in
- /// bytes); default is 200
+ /// Set the target's required jmp_buf buffer size (in bytes); default is 200
void setJumpBufSize(unsigned Size) {
JumpBufSize = Size;
}
- /// setJumpBufAlignment - Set the target's required jmp_buf buffer
- /// alignment (in bytes); default is 0
+ /// Set the target's required jmp_buf buffer alignment (in bytes); default is
+ /// 0
void setJumpBufAlignment(unsigned Align) {
JumpBufAlignment = Align;
}
- /// setMinFunctionAlignment - Set the target's minimum function alignment (in
- /// log2(bytes))
+ /// Set the target's minimum function alignment (in log2(bytes))
void setMinFunctionAlignment(unsigned Align) {
MinFunctionAlignment = Align;
}
- /// setPrefFunctionAlignment - Set the target's preferred function alignment.
- /// This should be set if there is a performance benefit to
- /// higher-than-minimum alignment (in log2(bytes))
+ /// Set the target's preferred function alignment. This should be set if
+ /// there is a performance benefit to higher-than-minimum alignment (in
+ /// log2(bytes))
void setPrefFunctionAlignment(unsigned Align) {
PrefFunctionAlignment = Align;
}
- /// setPrefLoopAlignment - Set the target's preferred loop alignment. Default
- /// alignment is zero, it means the target does not care about loop alignment.
- /// The alignment is specified in log2(bytes).
+ /// Set the target's preferred loop alignment. Default alignment is zero, it
+ /// means the target does not care about loop alignment. The alignment is
+ /// specified in log2(bytes). The target may also override
+ /// getPrefLoopAlignment to provide per-loop values.
void setPrefLoopAlignment(unsigned Align) {
PrefLoopAlignment = Align;
}
- /// setMinStackArgumentAlignment - Set the minimum stack alignment of an
- /// argument (in log2(bytes)).
+ /// Set the minimum stack alignment of an argument (in log2(bytes)).
void setMinStackArgumentAlignment(unsigned Align) {
MinStackArgumentAlignment = Align;
}
- /// setShouldFoldAtomicFences - Set if the target's implementation of the
- /// atomic operation intrinsics includes locking. Default is false.
- void setShouldFoldAtomicFences(bool fold) {
- ShouldFoldAtomicFences = fold;
- }
-
- /// setInsertFencesForAtomic - Set if the DAG builder should
- /// automatically insert fences and reduce the order of atomic memory
- /// operations to Monotonic.
+ /// Set if the DAG builder should automatically insert fences and reduce the
+ /// order of atomic memory operations to Monotonic.
void setInsertFencesForAtomic(bool fence) {
InsertFencesForAtomic = fence;
}
public:
//===--------------------------------------------------------------------===//
- // Lowering methods - These methods must be implemented by targets so that
- // the SelectionDAGBuilder code knows how to lower these.
+ // Addressing mode description hooks (used by LSR etc).
//
- /// LowerFormalArguments - This hook must be implemented to lower the
- /// incoming (formal) arguments, described by the Ins array, into the
- /// specified DAG. The implementation should fill in the InVals array
- /// with legal-type argument values, and return the resulting token
- /// chain value.
- ///
- virtual SDValue
- LowerFormalArguments(SDValue /*Chain*/, CallingConv::ID /*CallConv*/,
- bool /*isVarArg*/,
- const SmallVectorImpl<ISD::InputArg> &/*Ins*/,
- DebugLoc /*dl*/, SelectionDAG &/*DAG*/,
- SmallVectorImpl<SDValue> &/*InVals*/) const {
- llvm_unreachable("Not Implemented");
+ /// CodeGenPrepare sinks address calculations into the same BB as Load/Store
+ /// instructions reading the address. This allows as much computation as
+ /// possible to be done in the address mode for that operand. This hook lets
+ /// targets also pass back when this should be done on intrinsics which
+ /// load/store.
+ virtual bool GetAddrModeArguments(IntrinsicInst * /*I*/,
+ SmallVectorImpl<Value*> &/*Ops*/,
+ Type *&/*AccessTy*/) const {
+ return false;
}
- struct ArgListEntry {
- SDValue Node;
- Type* Ty;
- bool isSExt : 1;
- bool isZExt : 1;
- bool isInReg : 1;
- bool isSRet : 1;
- bool isNest : 1;
- bool isByVal : 1;
- uint16_t Alignment;
-
- ArgListEntry() : isSExt(false), isZExt(false), isInReg(false),
- isSRet(false), isNest(false), isByVal(false), Alignment(0) { }
- };
- typedef std::vector<ArgListEntry> ArgListTy;
-
- /// CallLoweringInfo - This structure contains all information that is
- /// necessary for lowering calls. It is passed to TLI::LowerCallTo when the
- /// SelectionDAG builder needs to lower a call, and targets will see this
- /// struct in their LowerCall implementation.
- struct CallLoweringInfo {
- SDValue Chain;
- Type *RetTy;
- bool RetSExt : 1;
- bool RetZExt : 1;
- bool IsVarArg : 1;
- bool IsInReg : 1;
- bool DoesNotReturn : 1;
- bool IsReturnValueUsed : 1;
-
- // IsTailCall should be modified by implementations of
- // TargetLowering::LowerCall that perform tail call conversions.
- bool IsTailCall;
-
- unsigned NumFixedArgs;
- CallingConv::ID CallConv;
- SDValue Callee;
- ArgListTy &Args;
- SelectionDAG &DAG;
- DebugLoc DL;
- ImmutableCallSite *CS;
- SmallVector<ISD::OutputArg, 32> Outs;
- SmallVector<SDValue, 32> OutVals;
- SmallVector<ISD::InputArg, 32> Ins;
-
-
- /// CallLoweringInfo - Constructs a call lowering context based on the
- /// ImmutableCallSite \p cs.
- CallLoweringInfo(SDValue chain, Type *retTy,
- FunctionType *FTy, bool isTailCall, SDValue callee,
- ArgListTy &args, SelectionDAG &dag, DebugLoc dl,
- ImmutableCallSite &cs)
- : Chain(chain), RetTy(retTy), RetSExt(cs.paramHasAttr(0, Attribute::SExt)),
- RetZExt(cs.paramHasAttr(0, Attribute::ZExt)), IsVarArg(FTy->isVarArg()),
- IsInReg(cs.paramHasAttr(0, Attribute::InReg)),
- DoesNotReturn(cs.doesNotReturn()),
- IsReturnValueUsed(!cs.getInstruction()->use_empty()),
- IsTailCall(isTailCall), NumFixedArgs(FTy->getNumParams()),
- CallConv(cs.getCallingConv()), Callee(callee), Args(args), DAG(dag),
- DL(dl), CS(&cs) {}
-
- /// CallLoweringInfo - Constructs a call lowering context based on the
- /// provided call information.
- CallLoweringInfo(SDValue chain, Type *retTy, bool retSExt, bool retZExt,
- bool isVarArg, bool isInReg, unsigned numFixedArgs,
- CallingConv::ID callConv, bool isTailCall,
- bool doesNotReturn, bool isReturnValueUsed, SDValue callee,
- ArgListTy &args, SelectionDAG &dag, DebugLoc dl)
- : Chain(chain), RetTy(retTy), RetSExt(retSExt), RetZExt(retZExt),
- IsVarArg(isVarArg), IsInReg(isInReg), DoesNotReturn(doesNotReturn),
- IsReturnValueUsed(isReturnValueUsed), IsTailCall(isTailCall),
- NumFixedArgs(numFixedArgs), CallConv(callConv), Callee(callee),
- Args(args), DAG(dag), DL(dl), CS(NULL) {}
+ /// This represents an addressing mode of:
+ /// BaseGV + BaseOffs + BaseReg + Scale*ScaleReg
+ /// If BaseGV is null, there is no BaseGV.
+ /// If BaseOffs is zero, there is no base offset.
+ /// If HasBaseReg is false, there is no base register.
+ /// If Scale is zero, there is no ScaleReg. Scale of 1 indicates a reg with
+ /// no scale.
+ struct AddrMode {
+ GlobalValue *BaseGV;
+ int64_t BaseOffs;
+ bool HasBaseReg;
+ int64_t Scale;
+ AddrMode() : BaseGV(nullptr), BaseOffs(0), HasBaseReg(false), Scale(0) {}
};
- /// LowerCallTo - This function lowers an abstract call to a function into an
- /// actual call. This returns a pair of operands. The first element is the
- /// return value for the function (if RetTy is not VoidTy). The second
- /// element is the outgoing token chain. It calls LowerCall to do the actual
- /// lowering.
- std::pair<SDValue, SDValue> LowerCallTo(CallLoweringInfo &CLI) const;
+ /// Return true if the addressing mode represented by AM is legal for this
+ /// target, for a load/store of the specified type.
+ ///
+ /// The type may be VoidTy, in which case only return true if the addressing
+ /// mode is legal for a load/store of any legal type. TODO: Handle
+ /// pre/postinc as well.
+ virtual bool isLegalAddressingMode(const AddrMode &AM, Type *Ty) const;
- /// LowerCall - This hook must be implemented to lower calls into the
- /// the specified DAG. The outgoing arguments to the call are described
- /// by the Outs array, and the values to be returned by the call are
- /// described by the Ins array. The implementation should fill in the
- /// InVals array with legal-type return values from the call, and return
- /// the resulting token chain value.
- virtual SDValue
- LowerCall(CallLoweringInfo &/*CLI*/,
- SmallVectorImpl<SDValue> &/*InVals*/) const {
- llvm_unreachable("Not Implemented");
+ /// \brief Return the cost of the scaling factor used in the addressing mode
+ /// represented by AM for this target, for a load/store of the specified type.
+ ///
+ /// If the AM is supported, the return value must be >= 0.
+ /// If the AM is not supported, it returns a negative value.
+ /// TODO: Handle pre/postinc as well.
+ virtual int getScalingFactorCost(const AddrMode &AM, Type *Ty) const {
+ // Default: assume that any scaling factor used in a legal AM is free.
+ if (isLegalAddressingMode(AM, Ty)) return 0;
+ return -1;
}
- /// HandleByVal - Target-specific cleanup for formal ByVal parameters.
- virtual void HandleByVal(CCState *, unsigned &, unsigned) const {}
-
- /// CanLowerReturn - This hook should be implemented to check whether the
- /// return values described by the Outs array can fit into the return
- /// registers. If false is returned, an sret-demotion is performed.
- ///
- virtual bool CanLowerReturn(CallingConv::ID /*CallConv*/,
- MachineFunction &/*MF*/, bool /*isVarArg*/,
- const SmallVectorImpl<ISD::OutputArg> &/*Outs*/,
- LLVMContext &/*Context*/) const
- {
- // Return true by default to get preexisting behavior.
+ /// Return true if the specified immediate is legal icmp immediate, that is
+ /// the target has icmp instructions which can compare a register against the
+ /// immediate without having to materialize the immediate into a register.
+ virtual bool isLegalICmpImmediate(int64_t) const {
return true;
}
- /// LowerReturn - This hook must be implemented to lower outgoing
- /// return values, described by the Outs array, into the specified
- /// DAG. The implementation should return the resulting token chain
- /// value.
- ///
- virtual SDValue
- LowerReturn(SDValue /*Chain*/, CallingConv::ID /*CallConv*/,
- bool /*isVarArg*/,
- const SmallVectorImpl<ISD::OutputArg> &/*Outs*/,
- const SmallVectorImpl<SDValue> &/*OutVals*/,
- DebugLoc /*dl*/, SelectionDAG &/*DAG*/) const {
- llvm_unreachable("Not Implemented");
+ /// Return true if the specified immediate is legal add immediate, that is the
+ /// target has add instructions which can add a register with the immediate
+ /// without having to materialize the immediate into a register.
+ virtual bool isLegalAddImmediate(int64_t) const {
+ return true;
}
- /// isUsedByReturnOnly - Return true if result of the specified node is used
- /// by a return node only. It also compute and return the input chain for the
- /// tail call.
- /// This is used to determine whether it is possible
- /// to codegen a libcall as tail call at legalization time.
- virtual bool isUsedByReturnOnly(SDNode *, SDValue &Chain) const {
+ /// Return true if it's significantly cheaper to shift a vector by a uniform
+ /// scalar than by an amount which will vary across each lane. On x86, for
+ /// example, there is a "psllw" instruction for the former case, but no simple
+ /// instruction for a general "a << b" operation on vectors.
+ virtual bool isVectorShiftByScalarCheap(Type *Ty) const {
return false;
}
- /// mayBeEmittedAsTailCall - Return true if the target may be able emit the
- /// call instruction as a tail call. This is used by optimization passes to
- /// determine if it's profitable to duplicate return instructions to enable
- /// tailcall optimization.
- virtual bool mayBeEmittedAsTailCall(CallInst *) const {
+ /// Return true if it's free to truncate a value of type Ty1 to type
+ /// Ty2. e.g. On x86 it's free to truncate a i32 value in register EAX to i16
+ /// by referencing its sub-register AX.
+ virtual bool isTruncateFree(Type * /*Ty1*/, Type * /*Ty2*/) const {
return false;
}
- /// getTypeForExtArgOrReturn - Return the type that should be used to zero or
- /// sign extend a zeroext/signext integer argument or return value.
- /// FIXME: Most C calling convention requires the return type to be promoted,
- /// but this is not true all the time, e.g. i1 on x86-64. It is also not
- /// necessary for non-C calling conventions. The frontend should handle this
- /// and include all of the necessary information.
- virtual EVT getTypeForExtArgOrReturn(LLVMContext &Context, EVT VT,
- ISD::NodeType /*ExtendKind*/) const {
- EVT MinVT = getRegisterType(Context, MVT::i32);
- return VT.bitsLT(MinVT) ? MinVT : VT;
+ /// Return true if a truncation from Ty1 to Ty2 is permitted when deciding
+ /// whether a call is in tail position. Typically this means that both results
+ /// would be assigned to the same register or stack slot, but it could mean
+ /// the target performs adequate checks of its own before proceeding with the
+ /// tail call.
+ virtual bool allowTruncateForTailCall(Type * /*Ty1*/, Type * /*Ty2*/) const {
+ return false;
}
- /// LowerOperationWrapper - This callback is invoked by the type legalizer
- /// to legalize nodes with an illegal operand type but legal result types.
- /// It replaces the LowerOperation callback in the type Legalizer.
- /// The reason we can not do away with LowerOperation entirely is that
- /// LegalizeDAG isn't yet ready to use this callback.
- /// TODO: Consider merging with ReplaceNodeResults.
-
- /// The target places new result values for the node in Results (their number
- /// and types must exactly match those of the original return values of
- /// the node), or leaves Results empty, which indicates that the node is not
- /// to be custom lowered after all.
- /// The default implementation calls LowerOperation.
- virtual void LowerOperationWrapper(SDNode *N,
- SmallVectorImpl<SDValue> &Results,
- SelectionDAG &DAG) const;
-
- /// LowerOperation - This callback is invoked for operations that are
- /// unsupported by the target, which are registered to use 'custom' lowering,
- /// and whose defined values are all legal.
- /// If the target has no operations that require custom lowering, it need not
- /// implement this. The default implementation of this aborts.
- virtual SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const;
-
- /// ReplaceNodeResults - This callback is invoked when a node result type is
- /// illegal for the target, and the operation was registered to use 'custom'
- /// lowering for that result type. The target places new result values for
- /// the node in Results (their number and types must exactly match those of
- /// the original return values of the node), or leaves Results empty, which
- /// indicates that the node is not to be custom lowered after all.
- ///
- /// If the target has no operations that require custom lowering, it need not
- /// implement this. The default implementation aborts.
- virtual void ReplaceNodeResults(SDNode * /*N*/,
- SmallVectorImpl<SDValue> &/*Results*/,
- SelectionDAG &/*DAG*/) const {
- llvm_unreachable("ReplaceNodeResults not implemented for this target!");
+ virtual bool isTruncateFree(EVT /*VT1*/, EVT /*VT2*/) const {
+ return false;
}
- /// getTargetNodeName() - This method returns the name of a target specific
- /// DAG node.
- virtual const char *getTargetNodeName(unsigned Opcode) const;
-
- /// createFastISel - This method returns a target specific FastISel object,
- /// or null if the target does not support "fast" ISel.
- virtual FastISel *createFastISel(FunctionLoweringInfo &,
- const TargetLibraryInfo *) const {
- return 0;
+ /// Return true if any actual instruction that defines a value of type Ty1
+ /// implicitly zero-extends the value to Ty2 in the result register.
+ ///
+ /// This does not necessarily include registers defined in unknown ways, such
+ /// as incoming arguments, or copies from unknown virtual registers. Also, if
+ /// isTruncateFree(Ty2, Ty1) is true, this does not necessarily apply to
+ /// truncate instructions. e.g. on x86-64, all instructions that define 32-bit
+ /// values implicit zero-extend the result out to 64 bits.
+ virtual bool isZExtFree(Type * /*Ty1*/, Type * /*Ty2*/) const {
+ return false;
}
- //===--------------------------------------------------------------------===//
- // Inline Asm Support hooks
- //
-
- /// ExpandInlineAsm - This hook allows the target to expand an inline asm
- /// call to be explicit llvm code if it wants to. This is useful for
- /// turning simple inline asms into LLVM intrinsics, which gives the
- /// compiler more information about the behavior of the code.
- virtual bool ExpandInlineAsm(CallInst *) const {
+ virtual bool isZExtFree(EVT /*VT1*/, EVT /*VT2*/) const {
return false;
}
- enum ConstraintType {
- C_Register, // Constraint represents specific register(s).
- C_RegisterClass, // Constraint represents any of register(s) in class.
- C_Memory, // Memory constraint.
- C_Other, // Something else.
- C_Unknown // Unsupported constraint.
- };
-
- enum ConstraintWeight {
- // Generic weights.
- CW_Invalid = -1, // No match.
- CW_Okay = 0, // Acceptable.
- CW_Good = 1, // Good weight.
- CW_Better = 2, // Better weight.
- CW_Best = 3, // Best weight.
-
- // Well-known weights.
- CW_SpecificReg = CW_Okay, // Specific register operands.
- CW_Register = CW_Good, // Register operands.
- CW_Memory = CW_Better, // Memory operands.
- CW_Constant = CW_Best, // Constant operand.
- CW_Default = CW_Okay // Default or don't know type.
- };
-
- /// AsmOperandInfo - This contains information for each constraint that we are
- /// lowering.
- struct AsmOperandInfo : public InlineAsm::ConstraintInfo {
- /// ConstraintCode - This contains the actual string for the code, like "m".
- /// TargetLowering picks the 'best' code from ConstraintInfo::Codes that
- /// most closely matches the operand.
- std::string ConstraintCode;
-
- /// ConstraintType - Information about the constraint code, e.g. Register,
- /// RegisterClass, Memory, Other, Unknown.
- TargetLowering::ConstraintType ConstraintType;
-
- /// CallOperandval - If this is the result output operand or a
- /// clobber, this is null, otherwise it is the incoming operand to the
- /// CallInst. This gets modified as the asm is processed.
- Value *CallOperandVal;
-
- /// ConstraintVT - The ValueType for the operand value.
- EVT ConstraintVT;
-
- /// isMatchingInputConstraint - Return true of this is an input operand that
- /// is a matching constraint like "4".
- bool isMatchingInputConstraint() const;
-
- /// getMatchedOperand - If this is an input matching constraint, this method
- /// returns the output operand it matches.
- unsigned getMatchedOperand() const;
-
- /// Copy constructor for copying from an AsmOperandInfo.
- AsmOperandInfo(const AsmOperandInfo &info)
- : InlineAsm::ConstraintInfo(info),
- ConstraintCode(info.ConstraintCode),
- ConstraintType(info.ConstraintType),
- CallOperandVal(info.CallOperandVal),
- ConstraintVT(info.ConstraintVT) {
- }
-
- /// Copy constructor for copying from a ConstraintInfo.
- AsmOperandInfo(const InlineAsm::ConstraintInfo &info)
- : InlineAsm::ConstraintInfo(info),
- ConstraintType(TargetLowering::C_Unknown),
- CallOperandVal(0), ConstraintVT(MVT::Other) {
- }
- };
-
- typedef std::vector<AsmOperandInfo> AsmOperandInfoVector;
-
- /// ParseConstraints - Split up the constraint string from the inline
- /// assembly value into the specific constraints and their prefixes,
- /// and also tie in the associated operand values.
- /// If this returns an empty vector, and if the constraint string itself
- /// isn't empty, there was an error parsing.
- virtual AsmOperandInfoVector ParseConstraints(ImmutableCallSite CS) const;
-
- /// Examine constraint type and operand type and determine a weight value.
- /// The operand object must already have been set up with the operand type.
- virtual ConstraintWeight getMultipleConstraintMatchWeight(
- AsmOperandInfo &info, int maIndex) const;
-
- /// Examine constraint string and operand type and determine a weight value.
- /// The operand object must already have been set up with the operand type.
- virtual ConstraintWeight getSingleConstraintMatchWeight(
- AsmOperandInfo &info, const char *constraint) const;
-
- /// ComputeConstraintToUse - Determines the constraint code and constraint
- /// type to use for the specific AsmOperandInfo, setting
- /// OpInfo.ConstraintCode and OpInfo.ConstraintType. If the actual operand
- /// being passed in is available, it can be passed in as Op, otherwise an
- /// empty SDValue can be passed.
- virtual void ComputeConstraintToUse(AsmOperandInfo &OpInfo,
- SDValue Op,
- SelectionDAG *DAG = 0) const;
-
- /// getConstraintType - Given a constraint, return the type of constraint it
- /// is for this target.
- virtual ConstraintType getConstraintType(const std::string &Constraint) const;
-
- /// getRegForInlineAsmConstraint - Given a physical register constraint (e.g.
- /// {edx}), return the register number and the register class for the
- /// register.
+ /// Return true if the target supplies and combines to a paired load
+ /// two loaded values of type LoadedType next to each other in memory.
+ /// RequiredAlignment gives the minimal alignment constraints that must be met
+ /// to be able to select this paired load.
///
- /// Given a register class constraint, like 'r', if this corresponds directly
- /// to an LLVM register class, return a register of 0 and the register class
- /// pointer.
+ /// This information is *not* used to generate actual paired loads, but it is
+ /// used to generate a sequence of loads that is easier to combine into a
+ /// paired load.
+ /// For instance, something like this:
+ /// a = load i64* addr
+ /// b = trunc i64 a to i32
+ /// c = lshr i64 a, 32
+ /// d = trunc i64 c to i32
+ /// will be optimized into:
+ /// b = load i32* addr1
+ /// d = load i32* addr2
+ /// Where addr1 = addr2 +/- sizeof(i32).
///
- /// This should only be used for C_Register constraints. On error,
- /// this returns a register number of 0 and a null register class pointer..
- virtual std::pair<unsigned, const TargetRegisterClass*>
- getRegForInlineAsmConstraint(const std::string &Constraint,
- EVT VT) const;
-
- /// LowerXConstraint - try to replace an X constraint, which matches anything,
- /// with another that has more specific requirements based on the type of the
- /// corresponding operand. This returns null if there is no replacement to
- /// make.
- virtual const char *LowerXConstraint(EVT ConstraintVT) const;
-
- /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
- /// vector. If it is invalid, don't add anything to Ops.
- virtual void LowerAsmOperandForConstraint(SDValue Op, std::string &Constraint,
- std::vector<SDValue> &Ops,
- SelectionDAG &DAG) const;
-
- //===--------------------------------------------------------------------===//
- // Instruction Emitting Hooks
- //
-
- // EmitInstrWithCustomInserter - This method should be implemented by targets
- // that mark instructions with the 'usesCustomInserter' flag. These
- // instructions are special in various ways, which require special support to
- // insert. The specified MachineInstr is created but not inserted into any
- // basic blocks, and this method is called to expand it into a sequence of
- // instructions, potentially also creating new basic blocks and control flow.
- virtual MachineBasicBlock *
- EmitInstrWithCustomInserter(MachineInstr *MI, MachineBasicBlock *MBB) const;
-
- /// AdjustInstrPostInstrSelection - This method should be implemented by
- /// targets that mark instructions with the 'hasPostISelHook' flag. These
- /// instructions must be adjusted after instruction selection by target hooks.
- /// e.g. To fill in optional defs for ARM 's' setting instructions.
- virtual void
- AdjustInstrPostInstrSelection(MachineInstr *MI, SDNode *Node) const;
-
- //===--------------------------------------------------------------------===//
- // Addressing mode description hooks (used by LSR etc).
- //
-
- /// GetAddrModeArguments - CodeGenPrepare sinks address calculations into the
- /// same BB as Load/Store instructions reading the address. This allows as
- /// much computation as possible to be done in the address mode for that
- /// operand. This hook lets targets also pass back when this should be done
- /// on intrinsics which load/store.
- virtual bool GetAddrModeArguments(IntrinsicInst *I,
- SmallVectorImpl<Value*> &Ops,
- Type *&AccessTy) const {
+ /// In other words, unless the target performs a post-isel load combining,
+ /// this information should not be provided because it will generate more
+ /// loads.
+ virtual bool hasPairedLoad(Type * /*LoadedType*/,
+ unsigned & /*RequiredAligment*/) const {
return false;
}
- /// isLegalAddressingMode - Return true if the addressing mode represented by
- /// AM is legal for this target, for a load/store of the specified type.
- /// The type may be VoidTy, in which case only return true if the addressing
- /// mode is legal for a load/store of any legal type.
- /// TODO: Handle pre/postinc as well.
- virtual bool isLegalAddressingMode(const AddrMode &AM, Type *Ty) const;
-
- /// isLegalICmpImmediate - Return true if the specified immediate is legal
- /// icmp immediate, that is the target has icmp instructions which can compare
- /// a register against the immediate without having to materialize the
- /// immediate into a register.
- virtual bool isLegalICmpImmediate(int64_t) const {
- return true;
- }
-
- /// isLegalAddImmediate - Return true if the specified immediate is legal
- /// add immediate, that is the target has add instructions which can add
- /// a register with the immediate without having to materialize the
- /// immediate into a register.
- virtual bool isLegalAddImmediate(int64_t) const {
- return true;
- }
-
- /// isTruncateFree - Return true if it's free to truncate a value of
- /// type Ty1 to type Ty2. e.g. On x86 it's free to truncate a i32 value in
- /// register EAX to i16 by referencing its sub-register AX.
- virtual bool isTruncateFree(Type * /*Ty1*/, Type * /*Ty2*/) const {
+ virtual bool hasPairedLoad(EVT /*LoadedType*/,
+ unsigned & /*RequiredAligment*/) const {
return false;
}
- virtual bool isTruncateFree(EVT /*VT1*/, EVT /*VT2*/) const {
- return false;
+ /// Return true if zero-extending the specific node Val to type VT2 is free
+ /// (either because it's implicitly zero-extended such as ARM ldrb / ldrh or
+ /// because it's folded such as X86 zero-extending loads).
+ virtual bool isZExtFree(SDValue Val, EVT VT2) const {
+ return isZExtFree(Val.getValueType(), VT2);
}
- /// isZExtFree - Return true if any actual instruction that defines a
- /// value of type Ty1 implicitly zero-extends the value to Ty2 in the result
- /// register. This does not necessarily include registers defined in
- /// unknown ways, such as incoming arguments, or copies from unknown
- /// virtual registers. Also, if isTruncateFree(Ty2, Ty1) is true, this
- /// does not necessarily apply to truncate instructions. e.g. on x86-64,
- /// all instructions that define 32-bit values implicit zero-extend the
- /// result out to 64 bits.
- virtual bool isZExtFree(Type * /*Ty1*/, Type * /*Ty2*/) const {
+ /// Return true if an fpext operation is free (for instance, because
+ /// single-precision floating-point numbers are implicitly extended to
+ /// double-precision).
+ virtual bool isFPExtFree(EVT VT) const {
+ assert(VT.isFloatingPoint());
return false;
}
- virtual bool isZExtFree(EVT /*VT1*/, EVT /*VT2*/) const {
+ /// Return true if an fneg operation is free to the point where it is never
+ /// worthwhile to replace it with a bitwise operation.
+ virtual bool isFNegFree(EVT VT) const {
+ assert(VT.isFloatingPoint());
return false;
}
- /// isZExtFree - Return true if zero-extending the specific node Val to type
- /// VT2 is free (either because it's implicitly zero-extended such as ARM
- /// ldrb / ldrh or because it's folded such as X86 zero-extending loads).
- virtual bool isZExtFree(SDValue Val, EVT VT2) const {
- return isZExtFree(Val.getValueType(), VT2);
+ /// Return true if an fabs operation is free to the point where it is never
+ /// worthwhile to replace it with a bitwise operation.
+ virtual bool isFAbsFree(EVT VT) const {
+ assert(VT.isFloatingPoint());
+ return false;
}
- /// isFNegFree - Return true if an fneg operation is free to the point where
- /// it is never worthwhile to replace it with a bitwise operation.
- virtual bool isFNegFree(EVT) const {
+ /// Return true if an FMA operation is faster than a pair of fmul and fadd
+ /// instructions. fmuladd intrinsics will be expanded to FMAs when this method
+ /// returns true, otherwise fmuladd is expanded to fmul + fadd.
+ ///
+ /// NOTE: This may be called before legalization on types for which FMAs are
+ /// not legal, but should return true if those types will eventually legalize
+ /// to types that support FMAs. After legalization, it will only be called on
+ /// types that support FMAs (via Legal or Custom actions)
+ virtual bool isFMAFasterThanFMulAndFAdd(EVT) const {
return false;
}
- /// isFAbsFree - Return true if an fneg operation is free to the point where
- /// it is never worthwhile to replace it with a bitwise operation.
- virtual bool isFAbsFree(EVT) const {
+ /// Return true if it's profitable to narrow operations of type VT1 to
+ /// VT2. e.g. on x86, it's profitable to narrow from i32 to i8 but not from
+ /// i32 to i16.
+ virtual bool isNarrowingProfitable(EVT /*VT1*/, EVT /*VT2*/) const {
return false;
}
- /// isFMAFasterThanMulAndAdd - Return true if an FMA operation is faster than
- /// a pair of mul and add instructions. fmuladd intrinsics will be expanded to
- /// FMAs when this method returns true (and FMAs are legal), otherwise fmuladd
- /// is expanded to mul + add.
- virtual bool isFMAFasterThanMulAndAdd(EVT) const {
+ /// \brief Return true if it is beneficial to convert a load of a constant to
+ /// just the constant itself.
+ /// On some targets it might be more efficient to use a combination of
+ /// arithmetic instructions to materialize the constant instead of loading it
+ /// from a constant pool.
+ virtual bool shouldConvertConstantLoadToIntImm(const APInt &Imm,
+ Type *Ty) const {
return false;
}
- /// isNarrowingProfitable - Return true if it's profitable to narrow
- /// operations of type VT1 to VT2. e.g. on x86, it's profitable to narrow
- /// from i32 to i8 but not from i32 to i16.
- virtual bool isNarrowingProfitable(EVT /*VT1*/, EVT /*VT2*/) const {
+ /// Return true if EXTRACT_SUBVECTOR is cheap for this result type
+ /// with this index. This is needed because EXTRACT_SUBVECTOR usually
+ /// has custom lowering that depends on the index of the first element,
+ /// and only the target knows which lowering is cheap.
+ virtual bool isExtractSubvectorCheap(EVT ResVT, unsigned Index) const {
return false;
}
- //===--------------------------------------------------------------------===//
- // Div utility functions
- //
- SDValue BuildExactSDIV(SDValue Op1, SDValue Op2, DebugLoc dl,
- SelectionDAG &DAG) const;
- SDValue BuildSDIV(SDNode *N, SelectionDAG &DAG, bool IsAfterLegalization,
- std::vector<SDNode*> *Created) const;
- SDValue BuildUDIV(SDNode *N, SelectionDAG &DAG, bool IsAfterLegalization,
- std::vector<SDNode*> *Created) const;
-
-
//===--------------------------------------------------------------------===//
// Runtime Library hooks
//
- /// setLibcallName - Rename the default libcall routine name for the specified
- /// libcall.
+ /// Rename the default libcall routine name for the specified libcall.
void setLibcallName(RTLIB::Libcall Call, const char *Name) {
LibcallRoutineNames[Call] = Name;
}
- /// getLibcallName - Get the libcall routine name for the specified libcall.
- ///
+ /// Get the libcall routine name for the specified libcall.
const char *getLibcallName(RTLIB::Libcall Call) const {
return LibcallRoutineNames[Call];
}
- /// setCmpLibcallCC - Override the default CondCode to be used to test the
- /// result of the comparison libcall against zero.
+ /// Override the default CondCode to be used to test the result of the
+ /// comparison libcall against zero.
void setCmpLibcallCC(RTLIB::Libcall Call, ISD::CondCode CC) {
CmpLibcallCCs[Call] = CC;
}
- /// getCmpLibcallCC - Get the CondCode that's to be used to test the result of
- /// the comparison libcall against zero.
+ /// Get the CondCode that's to be used to test the result of the comparison
+ /// libcall against zero.
ISD::CondCode getCmpLibcallCC(RTLIB::Libcall Call) const {
return CmpLibcallCCs[Call];
}
- /// setLibcallCallingConv - Set the CallingConv that should be used for the
- /// specified libcall.
+ /// Set the CallingConv that should be used for the specified libcall.
void setLibcallCallingConv(RTLIB::Libcall Call, CallingConv::ID CC) {
LibcallCallingConvs[Call] = CC;
}
- /// getLibcallCallingConv - Get the CallingConv that should be used for the
- /// specified libcall.
+ /// Get the CallingConv that should be used for the specified libcall.
CallingConv::ID getLibcallCallingConv(RTLIB::Libcall Call) const {
return LibcallCallingConvs[Call];
}
private:
const TargetMachine &TM;
- const DataLayout *TD;
- const TargetLoweringObjectFile &TLOF;
-
- /// PointerTy - The type to use for pointers for the default address space,
- /// usually i32 or i64.
- ///
- MVT PointerTy;
+ const DataLayout *DL;
- /// IsLittleEndian - True if this is a little endian target.
- ///
+ /// True if this is a little endian target.
bool IsLittleEndian;
- /// SelectIsExpensive - Tells the code generator not to expand operations
- /// into sequences that use the select operations if possible.
+ /// Tells the code generator not to expand operations into sequences that use
+ /// the select operations if possible.
bool SelectIsExpensive;
- /// IntDivIsCheap - Tells the code generator not to expand integer divides by
- /// constants into a sequence of muls, adds, and shifts. This is a hack until
- /// a real cost model is in place. If we ever optimize for size, this will be
- /// set to true unconditionally.
+ /// Tells the code generator that the target has multiple (allocatable)
+ /// condition registers that can be used to store the results of comparisons
+ /// for use by selects and conditional branches. With multiple condition
+ /// registers, the code generator will not aggressively sink comparisons into
+ /// the blocks of their users.
+ bool HasMultipleConditionRegisters;
+
+ /// Tells the code generator that the target has BitExtract instructions.
+ /// The code generator will aggressively sink "shift"s into the blocks of
+ /// their users if the users will generate "and" instructions which can be
+ /// combined with "shift" to BitExtract instructions.
+ bool HasExtractBitsInsn;
+
+ /// Tells the code generator not to expand integer divides by constants into a
+ /// sequence of muls, adds, and shifts. This is a hack until a real cost
+ /// model is in place. If we ever optimize for size, this will be set to true
+ /// unconditionally.
bool IntDivIsCheap;
- /// BypassSlowDivMap - Tells the code generator to bypass slow divide or
- /// remainder instructions. For example, BypassSlowDivWidths[32,8] tells the
- /// code generator to bypass 32-bit integer div/rem with an 8-bit unsigned
- /// integer div/rem when the operands are positive and less than 256.
+ // Don't expand fsqrt with an approximation based on the inverse sqrt.
+ bool FsqrtIsCheap;
+
+ /// Tells the code generator to bypass slow divide or remainder
+ /// instructions. For example, BypassSlowDivWidths[32,8] tells the code
+ /// generator to bypass 32-bit integer div/rem with an 8-bit unsigned integer
+ /// div/rem when the operands are positive and less than 256.
DenseMap <unsigned int, unsigned int> BypassSlowDivWidths;
- /// Pow2DivIsCheap - Tells the code generator that it shouldn't generate
- /// srl/add/sra for a signed divide by power of two, and let the target handle
- /// it.
- bool Pow2DivIsCheap;
+ /// Tells the code generator that it shouldn't generate sra/srl/add/sra for a
+ /// signed divide by power of two; let the target handle it.
+ bool Pow2SDivIsCheap;
- /// JumpIsExpensive - Tells the code generator that it shouldn't generate
- /// extra flow control instructions and should attempt to combine flow
- /// control instructions via predication.
+ /// Tells the code generator that it shouldn't generate extra flow control
+ /// instructions and should attempt to combine flow control instructions via
+ /// predication.
bool JumpIsExpensive;
- /// UseUnderscoreSetJmp - This target prefers to use _setjmp to implement
- /// llvm.setjmp. Defaults to false.
+ /// Whether the target supports or cares about preserving floating point
+ /// exception behavior.
+ bool HasFloatingPointExceptions;
+
+ /// This target prefers to use _setjmp to implement llvm.setjmp.
+ ///
+ /// Defaults to false.
bool UseUnderscoreSetJmp;
- /// UseUnderscoreLongJmp - This target prefers to use _longjmp to implement
- /// llvm.longjmp. Defaults to false.
+ /// This target prefers to use _longjmp to implement llvm.longjmp.
+ ///
+ /// Defaults to false.
bool UseUnderscoreLongJmp;
- /// SupportJumpTables - Whether the target can generate code for jumptables.
- /// If it's not true, then each jumptable must be lowered into if-then-else's.
- bool SupportJumpTables;
-
- /// MinimumJumpTableEntries - Number of blocks threshold to use jump tables.
+ /// Number of blocks threshold to use jump tables.
int MinimumJumpTableEntries;
- /// BooleanContents - Information about the contents of the high-bits in
- /// boolean values held in a type wider than i1. See getBooleanContents.
+ /// Information about the contents of the high-bits in boolean values held in
+ /// a type wider than i1. See getBooleanContents.
BooleanContent BooleanContents;
- /// BooleanVectorContents - Information about the contents of the high-bits
- /// in boolean vector values when the element type is wider than i1. See
- /// getBooleanContents.
+
+ /// Information about the contents of the high-bits in boolean values held in
+ /// a type wider than i1. See getBooleanContents.
+ BooleanContent BooleanFloatContents;
+
+ /// Information about the contents of the high-bits in boolean vector values
+ /// when the element type is wider than i1. See getBooleanContents.
BooleanContent BooleanVectorContents;
- /// SchedPreferenceInfo - The target scheduling preference: shortest possible
- /// total cycles or lowest register usage.
+ /// The target scheduling preference: shortest possible total cycles or lowest
+ /// register usage.
Sched::Preference SchedPreferenceInfo;
- /// JumpBufSize - The size, in bytes, of the target's jmp_buf buffers
+ /// The size, in bytes, of the target's jmp_buf buffers
unsigned JumpBufSize;
- /// JumpBufAlignment - The alignment, in bytes, of the target's jmp_buf
- /// buffers
+ /// The alignment, in bytes, of the target's jmp_buf buffers
unsigned JumpBufAlignment;
- /// MinStackArgumentAlignment - The minimum alignment that any argument
- /// on the stack needs to have.
- ///
+ /// The minimum alignment that any argument on the stack needs to have.
unsigned MinStackArgumentAlignment;
- /// MinFunctionAlignment - The minimum function alignment (used when
- /// optimizing for size, and to prevent explicitly provided alignment
- /// from leading to incorrect code).
- ///
+ /// The minimum function alignment (used when optimizing for size, and to
+ /// prevent explicitly provided alignment from leading to incorrect code).
unsigned MinFunctionAlignment;
- /// PrefFunctionAlignment - The preferred function alignment (used when
- /// alignment unspecified and optimizing for speed).
- ///
+ /// The preferred function alignment (used when alignment unspecified and
+ /// optimizing for speed).
unsigned PrefFunctionAlignment;
- /// PrefLoopAlignment - The preferred loop alignment.
- ///
+ /// The preferred loop alignment.
unsigned PrefLoopAlignment;
- /// ShouldFoldAtomicFences - Whether fencing MEMBARRIER instructions should
- /// be folded into the enclosed atomic intrinsic instruction by the
- /// combiner.
- bool ShouldFoldAtomicFences;
-
- /// InsertFencesForAtomic - Whether the DAG builder should automatically
- /// insert fences and reduce ordering for atomics. (This will be set for
- /// for most architectures with weak memory ordering.)
+ /// Whether the DAG builder should automatically insert fences and reduce
+ /// ordering for atomics. (This will be set for for most architectures with
+ /// weak memory ordering.)
bool InsertFencesForAtomic;
- /// StackPointerRegisterToSaveRestore - If set to a physical register, this
- /// specifies the register that llvm.savestack/llvm.restorestack should save
- /// and restore.
+ /// If set to a physical register, this specifies the register that
+ /// llvm.savestack/llvm.restorestack should save and restore.
unsigned StackPointerRegisterToSaveRestore;
- /// ExceptionPointerRegister - If set to a physical register, this specifies
- /// the register that receives the exception address on entry to a landing
- /// pad.
+ /// If set to a physical register, this specifies the register that receives
+ /// the exception address on entry to a landing pad.
unsigned ExceptionPointerRegister;
- /// ExceptionSelectorRegister - If set to a physical register, this specifies
- /// the register that receives the exception typeid on entry to a landing
- /// pad.
+ /// If set to a physical register, this specifies the register that receives
+ /// the exception typeid on entry to a landing pad.
unsigned ExceptionSelectorRegister;
- /// RegClassForVT - This indicates the default register class to use for
- /// each ValueType the target supports natively.
+ /// This indicates the default register class to use for each ValueType the
+ /// target supports natively.
const TargetRegisterClass *RegClassForVT[MVT::LAST_VALUETYPE];
unsigned char NumRegistersForVT[MVT::LAST_VALUETYPE];
MVT RegisterTypeForVT[MVT::LAST_VALUETYPE];
- /// RepRegClassForVT - This indicates the "representative" register class to
- /// use for each ValueType the target supports natively. This information is
- /// used by the scheduler to track register pressure. By default, the
- /// representative register class is the largest legal super-reg register
- /// class of the register class of the specified type. e.g. On x86, i8, i16,
- /// and i32's representative class would be GR32.
+ /// This indicates the "representative" register class to use for each
+ /// ValueType the target supports natively. This information is used by the
+ /// scheduler to track register pressure. By default, the representative
+ /// register class is the largest legal super-reg register class of the
+ /// register class of the specified type. e.g. On x86, i8, i16, and i32's
+ /// representative class would be GR32.
const TargetRegisterClass *RepRegClassForVT[MVT::LAST_VALUETYPE];
- /// RepRegClassCostForVT - This indicates the "cost" of the "representative"
- /// register class for each ValueType. The cost is used by the scheduler to
- /// approximate register pressure.
+ /// This indicates the "cost" of the "representative" register class for each
+ /// ValueType. The cost is used by the scheduler to approximate register
+ /// pressure.
uint8_t RepRegClassCostForVT[MVT::LAST_VALUETYPE];
- /// TransformToType - For any value types we are promoting or expanding, this
- /// contains the value type that we are changing to. For Expanded types, this
- /// contains one step of the expand (e.g. i64 -> i32), even if there are
- /// multiple steps required (e.g. i64 -> i16). For types natively supported
- /// by the system, this holds the same type (e.g. i32 -> i32).
+ /// For any value types we are promoting or expanding, this contains the value
+ /// type that we are changing to. For Expanded types, this contains one step
+ /// of the expand (e.g. i64 -> i32), even if there are multiple steps required
+ /// (e.g. i64 -> i16). For types natively supported by the system, this holds
+ /// the same type (e.g. i32 -> i32).
MVT TransformToType[MVT::LAST_VALUETYPE];
- /// OpActions - For each operation and each value type, keep a LegalizeAction
- /// that indicates how instruction selection should deal with the operation.
- /// Most operations are Legal (aka, supported natively by the target), but
+ /// For each operation and each value type, keep a LegalizeAction that
+ /// indicates how instruction selection should deal with the operation. Most
+ /// operations are Legal (aka, supported natively by the target), but
/// operations that are not should be described. Note that operations on
/// non-legal value types are not described here.
uint8_t OpActions[MVT::LAST_VALUETYPE][ISD::BUILTIN_OP_END];
- /// LoadExtActions - For each load extension type and each value type,
- /// keep a LegalizeAction that indicates how instruction selection should deal
- /// with a load of a specific value type and extension type.
- uint8_t LoadExtActions[MVT::LAST_VALUETYPE][ISD::LAST_LOADEXT_TYPE];
+ /// For each load extension type and each value type, keep a LegalizeAction
+ /// that indicates how instruction selection should deal with a load of a
+ /// specific value type and extension type.
+ uint8_t LoadExtActions[MVT::LAST_VALUETYPE][MVT::LAST_VALUETYPE]
+ [ISD::LAST_LOADEXT_TYPE];
- /// TruncStoreActions - For each value type pair keep a LegalizeAction that
- /// indicates whether a truncating store of a specific value type and
- /// truncating type is legal.
+ /// For each value type pair keep a LegalizeAction that indicates whether a
+ /// truncating store of a specific value type and truncating type is legal.
uint8_t TruncStoreActions[MVT::LAST_VALUETYPE][MVT::LAST_VALUETYPE];
- /// IndexedModeActions - For each indexed mode and each value type,
- /// keep a pair of LegalizeAction that indicates how instruction
- /// selection should deal with the load / store. The first dimension is the
- /// value_type for the reference. The second dimension represents the various
- /// modes for load store.
+ /// For each indexed mode and each value type, keep a pair of LegalizeAction
+ /// that indicates how instruction selection should deal with the load /
+ /// store.
+ ///
+ /// The first dimension is the value_type for the reference. The second
+ /// dimension represents the various modes for load store.
uint8_t IndexedModeActions[MVT::LAST_VALUETYPE][ISD::LAST_INDEXED_MODE];
- /// CondCodeActions - For each condition code (ISD::CondCode) keep a
- /// LegalizeAction that indicates how instruction selection should
- /// deal with the condition code.
- /// Because each CC action takes up 2 bits, we need to have the array size
- /// be large enough to fit all of the value types. This can be done by
- /// dividing the MVT::LAST_VALUETYPE by 32 and adding one.
- uint64_t CondCodeActions[ISD::SETCC_INVALID][(MVT::LAST_VALUETYPE / 32) + 1];
+ /// For each condition code (ISD::CondCode) keep a LegalizeAction that
+ /// indicates how instruction selection should deal with the condition code.
+ ///
+ /// Because each CC action takes up 2 bits, we need to have the array size be
+ /// large enough to fit all of the value types. This can be done by rounding
+ /// up the MVT::LAST_VALUETYPE value to the next multiple of 16.
+ uint32_t CondCodeActions[ISD::SETCC_INVALID][(MVT::LAST_VALUETYPE + 15) / 16];
ValueTypeActionImpl ValueTypeActions;
LegalizeTypeAction LA = ValueTypeActions.getTypeAction(SVT);
assert(
- (LA == TypeLegal ||
+ (LA == TypeLegal || LA == TypeSoftenFloat ||
ValueTypeActions.getTypeAction(NVT) != TypePromoteInteger)
&& "Promote may not follow Expand or Promote");
if (LA == TypeSplitVector)
- NVT = MVT::getVectorVT(SVT.getVectorElementType(),
- SVT.getVectorNumElements() / 2);
+ return LegalizeKind(LA, EVT::getVectorVT(Context,
+ SVT.getVectorElementType(),
+ SVT.getVectorNumElements()/2));
+ if (LA == TypeScalarizeVector)
+ return LegalizeKind(LA, SVT.getVectorElementType());
return LegalizeKind(LA, NVT);
}
if (NumElts == 1)
return LegalizeKind(TypeScalarizeVector, EltVT);
- // Try to widen vector elements until a legal type is found.
+ // Try to widen vector elements until the element type is a power of two and
+ // promote it to a legal type later on, for example:
+ // <3 x i8> -> <4 x i8> -> <4 x i32>
if (EltVT.isInteger()) {
// Vectors with a number of elements that is not a power of two are always
- // widened, for example <3 x float> -> <4 x float>.
+ // widened, for example <3 x i8> -> <4 x i8>.
if (!VT.isPow2VectorType()) {
NumElts = (unsigned)NextPowerOf2(NumElts);
EVT NVT = EVT::getVectorVT(Context, EltVT, NumElts);
// or until the element integer type is too big. If a legal type was not
// found, fallback to the usual mechanism of widening/splitting the
// vector.
+ EVT OldEltVT = EltVT;
while (1) {
// Increase the bitwidth of the element to the next pow-of-two
// (which is greater than 8 bits).
// Stop trying when getting a non-simple element type.
// Note that vector elements may be greater than legal vector element
- // types. Example: X86 XMM registers hold 64bit element on 32bit systems.
+ // types. Example: X86 XMM registers hold 64bit element on 32bit
+ // systems.
if (!EltVT.isSimple()) break;
// Build a new vector type and check if it is legal.
return LegalizeKind(TypePromoteInteger,
EVT::getVectorVT(Context, EltVT, NumElts));
}
+
+ // Reset the type to the unexpanded type if we did not find a legal vector
+ // type with a promoted vector element type.
+ EltVT = OldEltVT;
}
// Try to widen the vector until a legal type is found.
private:
std::vector<std::pair<MVT, const TargetRegisterClass*> > AvailableRegClasses;
- /// TargetDAGCombineArray - Targets can specify ISD nodes that they would
- /// like PerformDAGCombine callbacks for by calling setTargetDAGCombine(),
- /// which sets a bit in this array.
+ /// Targets can specify ISD nodes that they would like PerformDAGCombine
+ /// callbacks for by calling setTargetDAGCombine(), which sets a bit in this
+ /// array.
unsigned char
TargetDAGCombineArray[(ISD::BUILTIN_OP_END+CHAR_BIT-1)/CHAR_BIT];
- /// PromoteToType - For operations that must be promoted to a specific type,
- /// this holds the destination type. This map should be sparse, so don't hold
- /// it as an array.
+ /// For operations that must be promoted to a specific type, this holds the
+ /// destination type. This map should be sparse, so don't hold it as an
+ /// array.
///
/// Targets add entries to this map with AddPromotedToType(..), clients access
/// this with getTypeToPromoteTo(..).
std::map<std::pair<unsigned, MVT::SimpleValueType>, MVT::SimpleValueType>
PromoteToType;
- /// LibcallRoutineNames - Stores the name each libcall.
- ///
+ /// Stores the name each libcall.
const char *LibcallRoutineNames[RTLIB::UNKNOWN_LIBCALL];
- /// CmpLibcallCCs - The ISD::CondCode that should be used to test the result
- /// of each of the comparison libcall against zero.
+ /// The ISD::CondCode that should be used to test the result of each of the
+ /// comparison libcall against zero.
ISD::CondCode CmpLibcallCCs[RTLIB::UNKNOWN_LIBCALL];
- /// LibcallCallingConvs - Stores the CallingConv that should be used for each
- /// libcall.
+ /// Stores the CallingConv that should be used for each libcall.
CallingConv::ID LibcallCallingConvs[RTLIB::UNKNOWN_LIBCALL];
protected:
+ /// \brief Specify maximum number of store instructions per memset call.
+ ///
/// When lowering \@llvm.memset this field specifies the maximum number of
/// store operations that may be substituted for the call to memset. Targets
/// must set this value based on the cost threshold for that target. Targets
/// alignment restrictions. For example, storing 9 bytes on a 32-bit machine
/// with 16-bit alignment would result in four 2-byte stores and one 1-byte
/// store. This only applies to setting a constant array of a constant size.
- /// @brief Specify maximum number of store instructions per memset call.
- unsigned maxStoresPerMemset;
+ unsigned MaxStoresPerMemset;
/// Maximum number of stores operations that may be substituted for the call
/// to memset, used for functions with OptSize attribute.
- unsigned maxStoresPerMemsetOptSize;
+ unsigned MaxStoresPerMemsetOptSize;
+ /// \brief Specify maximum bytes of store instructions per memcpy call.
+ ///
/// When lowering \@llvm.memcpy this field specifies the maximum number of
/// store operations that may be substituted for a call to memcpy. Targets
/// must set this value based on the cost threshold for that target. Targets
/// with 32-bit alignment would result in one 4-byte store, a one 2-byte store
/// and one 1-byte store. This only applies to copying a constant array of
/// constant size.
- /// @brief Specify maximum bytes of store instructions per memcpy call.
- unsigned maxStoresPerMemcpy;
+ unsigned MaxStoresPerMemcpy;
- /// Maximum number of store operations that may be substituted for a call
- /// to memcpy, used for functions with OptSize attribute.
- unsigned maxStoresPerMemcpyOptSize;
+ /// Maximum number of store operations that may be substituted for a call to
+ /// memcpy, used for functions with OptSize attribute.
+ unsigned MaxStoresPerMemcpyOptSize;
+ /// \brief Specify maximum bytes of store instructions per memmove call.
+ ///
/// When lowering \@llvm.memmove this field specifies the maximum number of
/// store instructions that may be substituted for a call to memmove. Targets
/// must set this value based on the cost threshold for that target. Targets
/// alignment restrictions. For example, moving 9 bytes on a 32-bit machine
/// with 8-bit alignment would result in nine 1-byte stores. This only
/// applies to copying a constant array of constant size.
- /// @brief Specify maximum bytes of store instructions per memmove call.
- unsigned maxStoresPerMemmove;
+ unsigned MaxStoresPerMemmove;
- /// Maximum number of store instructions that may be substituted for a call
- /// to memmove, used for functions with OpSize attribute.
- unsigned maxStoresPerMemmoveOptSize;
+ /// Maximum number of store instructions that may be substituted for a call to
+ /// memmove, used for functions with OpSize attribute.
+ unsigned MaxStoresPerMemmoveOptSize;
- /// This field specifies whether the target can benefit from code placement
- /// optimization.
- bool benefitFromCodePlacementOpt;
+ /// Tells the code generator that select is more expensive than a branch if
+ /// the branch is usually predicted right.
+ bool PredictableSelectIsExpensive;
- /// predictableSelectIsExpensive - Tells the code generator that select is
- /// more expensive than a branch if the branch is usually predicted right.
- bool predictableSelectIsExpensive;
+ /// MaskAndBranchFoldingIsLegal - Indicates if the target supports folding
+ /// a mask of a single bit, a compare, and a branch into a single instruction.
+ bool MaskAndBranchFoldingIsLegal;
-private:
- /// isLegalRC - Return true if the value types that can be represented by the
- /// specified register class are all legal.
+ /// \see enableExtLdPromotion.
+ bool EnableExtLdPromotion;
+
+protected:
+ /// Return true if the value types that can be represented by the specified
+ /// register class are all legal.
bool isLegalRC(const TargetRegisterClass *RC) const;
+
+ /// Replace/modify any TargetFrameIndex operands with a targte-dependent
+ /// sequence of memory operands that is recognized by PrologEpilogInserter.
+ MachineBasicBlock *emitPatchPoint(MachineInstr *MI, MachineBasicBlock *MBB) const;
+};
+
+/// This class defines information used to lower LLVM code to legal SelectionDAG
+/// operators that the target instruction selector can accept natively.
+///
+/// This class also defines callbacks that targets must implement to lower
+/// target-specific constructs to SelectionDAG operators.
+class TargetLowering : public TargetLoweringBase {
+ TargetLowering(const TargetLowering&) LLVM_DELETED_FUNCTION;
+ void operator=(const TargetLowering&) LLVM_DELETED_FUNCTION;
+
+public:
+ /// NOTE: The TargetMachine owns TLOF.
+ explicit TargetLowering(const TargetMachine &TM);
+
+ /// Returns true by value, base pointer and offset pointer and addressing mode
+ /// by reference if the node's address can be legally represented as
+ /// pre-indexed load / store address.
+ virtual bool getPreIndexedAddressParts(SDNode * /*N*/, SDValue &/*Base*/,
+ SDValue &/*Offset*/,
+ ISD::MemIndexedMode &/*AM*/,
+ SelectionDAG &/*DAG*/) const {
+ return false;
+ }
+
+ /// Returns true by value, base pointer and offset pointer and addressing mode
+ /// by reference if this node can be combined with a load / store to form a
+ /// post-indexed load / store.
+ virtual bool getPostIndexedAddressParts(SDNode * /*N*/, SDNode * /*Op*/,
+ SDValue &/*Base*/,
+ SDValue &/*Offset*/,
+ ISD::MemIndexedMode &/*AM*/,
+ SelectionDAG &/*DAG*/) const {
+ return false;
+ }
+
+ /// Return the entry encoding for a jump table in the current function. The
+ /// returned value is a member of the MachineJumpTableInfo::JTEntryKind enum.
+ virtual unsigned getJumpTableEncoding() const;
+
+ virtual const MCExpr *
+ LowerCustomJumpTableEntry(const MachineJumpTableInfo * /*MJTI*/,
+ const MachineBasicBlock * /*MBB*/, unsigned /*uid*/,
+ MCContext &/*Ctx*/) const {
+ llvm_unreachable("Need to implement this hook if target has custom JTIs");
+ }
+
+ /// Returns relocation base for the given PIC jumptable.
+ virtual SDValue getPICJumpTableRelocBase(SDValue Table,
+ SelectionDAG &DAG) const;
+
+ /// This returns the relocation base for the given PIC jumptable, the same as
+ /// getPICJumpTableRelocBase, but as an MCExpr.
+ virtual const MCExpr *
+ getPICJumpTableRelocBaseExpr(const MachineFunction *MF,
+ unsigned JTI, MCContext &Ctx) const;
+
+ /// Return true if folding a constant offset with the given GlobalAddress is
+ /// legal. It is frequently not legal in PIC relocation models.
+ virtual bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const;
+
+ bool isInTailCallPosition(SelectionDAG &DAG, SDNode *Node,
+ SDValue &Chain) const;
+
+ void softenSetCCOperands(SelectionDAG &DAG, EVT VT,
+ SDValue &NewLHS, SDValue &NewRHS,
+ ISD::CondCode &CCCode, SDLoc DL) const;
+
+ /// Returns a pair of (return value, chain).
+ std::pair<SDValue, SDValue> makeLibCall(SelectionDAG &DAG, RTLIB::Libcall LC,
+ EVT RetVT, const SDValue *Ops,
+ unsigned NumOps, bool isSigned,
+ SDLoc dl, bool doesNotReturn = false,
+ bool isReturnValueUsed = true) const;
+
+ //===--------------------------------------------------------------------===//
+ // TargetLowering Optimization Methods
+ //
+
+ /// A convenience struct that encapsulates a DAG, and two SDValues for
+ /// returning information from TargetLowering to its clients that want to
+ /// combine.
+ struct TargetLoweringOpt {
+ SelectionDAG &DAG;
+ bool LegalTys;
+ bool LegalOps;
+ SDValue Old;
+ SDValue New;
+
+ explicit TargetLoweringOpt(SelectionDAG &InDAG,
+ bool LT, bool LO) :
+ DAG(InDAG), LegalTys(LT), LegalOps(LO) {}
+
+ bool LegalTypes() const { return LegalTys; }
+ bool LegalOperations() const { return LegalOps; }
+
+ bool CombineTo(SDValue O, SDValue N) {
+ Old = O;
+ New = N;
+ return true;
+ }
+
+ /// Check to see if the specified operand of the specified instruction is a
+ /// constant integer. If so, check to see if there are any bits set in the
+ /// constant that are not demanded. If so, shrink the constant and return
+ /// true.
+ bool ShrinkDemandedConstant(SDValue Op, const APInt &Demanded);
+
+ /// Convert x+y to (VT)((SmallVT)x+(SmallVT)y) if the casts are free. This
+ /// uses isZExtFree and ZERO_EXTEND for the widening cast, but it could be
+ /// generalized for targets with other types of implicit widening casts.
+ bool ShrinkDemandedOp(SDValue Op, unsigned BitWidth, const APInt &Demanded,
+ SDLoc dl);
+ };
+
+ /// Look at Op. At this point, we know that only the DemandedMask bits of the
+ /// result of Op are ever used downstream. If we can use this information to
+ /// simplify Op, create a new simplified DAG node and return true, returning
+ /// the original and new nodes in Old and New. Otherwise, analyze the
+ /// expression and return a mask of KnownOne and KnownZero bits for the
+ /// expression (used to simplify the caller). The KnownZero/One bits may only
+ /// be accurate for those bits in the DemandedMask.
+ bool SimplifyDemandedBits(SDValue Op, const APInt &DemandedMask,
+ APInt &KnownZero, APInt &KnownOne,
+ TargetLoweringOpt &TLO, unsigned Depth = 0) const;
+
+ /// Determine which of the bits specified in Mask are known to be either zero
+ /// or one and return them in the KnownZero/KnownOne bitsets.
+ virtual void computeKnownBitsForTargetNode(const SDValue Op,
+ APInt &KnownZero,
+ APInt &KnownOne,
+ const SelectionDAG &DAG,
+ unsigned Depth = 0) const;
+
+ /// This method can be implemented by targets that want to expose additional
+ /// information about sign bits to the DAG Combiner.
+ virtual unsigned ComputeNumSignBitsForTargetNode(SDValue Op,
+ const SelectionDAG &DAG,
+ unsigned Depth = 0) const;
+
+ struct DAGCombinerInfo {
+ void *DC; // The DAG Combiner object.
+ CombineLevel Level;
+ bool CalledByLegalizer;
+ public:
+ SelectionDAG &DAG;
+
+ DAGCombinerInfo(SelectionDAG &dag, CombineLevel level, bool cl, void *dc)
+ : DC(dc), Level(level), CalledByLegalizer(cl), DAG(dag) {}
+
+ bool isBeforeLegalize() const { return Level == BeforeLegalizeTypes; }
+ bool isBeforeLegalizeOps() const { return Level < AfterLegalizeVectorOps; }
+ bool isAfterLegalizeVectorOps() const {
+ return Level == AfterLegalizeDAG;
+ }
+ CombineLevel getDAGCombineLevel() { return Level; }
+ bool isCalledByLegalizer() const { return CalledByLegalizer; }
+
+ void AddToWorklist(SDNode *N);
+ void RemoveFromWorklist(SDNode *N);
+ SDValue CombineTo(SDNode *N, const std::vector<SDValue> &To,
+ bool AddTo = true);
+ SDValue CombineTo(SDNode *N, SDValue Res, bool AddTo = true);
+ SDValue CombineTo(SDNode *N, SDValue Res0, SDValue Res1, bool AddTo = true);
+
+ void CommitTargetLoweringOpt(const TargetLoweringOpt &TLO);
+ };
+
+ /// Return if the N is a constant or constant vector equal to the true value
+ /// from getBooleanContents().
+ bool isConstTrueVal(const SDNode *N) const;
+
+ /// Return if the N is a constant or constant vector equal to the false value
+ /// from getBooleanContents().
+ bool isConstFalseVal(const SDNode *N) const;
+
+ /// Try to simplify a setcc built with the specified operands and cc. If it is
+ /// unable to simplify it, return a null SDValue.
+ SDValue SimplifySetCC(EVT VT, SDValue N0, SDValue N1,
+ ISD::CondCode Cond, bool foldBooleans,
+ DAGCombinerInfo &DCI, SDLoc dl) const;
+
+ /// Returns true (and the GlobalValue and the offset) if the node is a
+ /// GlobalAddress + offset.
+ virtual bool
+ isGAPlusOffset(SDNode *N, const GlobalValue* &GA, int64_t &Offset) const;
+
+ /// This method will be invoked for all target nodes and for any
+ /// target-independent nodes that the target has registered with invoke it
+ /// for.
+ ///
+ /// The semantics are as follows:
+ /// Return Value:
+ /// SDValue.Val == 0 - No change was made
+ /// SDValue.Val == N - N was replaced, is dead, and is already handled.
+ /// otherwise - N should be replaced by the returned Operand.
+ ///
+ /// In addition, methods provided by DAGCombinerInfo may be used to perform
+ /// more complex transformations.
+ ///
+ virtual SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const;
+
+ /// Return true if it is profitable to move a following shift through this
+ // node, adjusting any immediate operands as necessary to preserve semantics.
+ // This transformation may not be desirable if it disrupts a particularly
+ // auspicious target-specific tree (e.g. bitfield extraction in AArch64).
+ // By default, it returns true.
+ virtual bool isDesirableToCommuteWithShift(const SDNode *N /*Op*/) const {
+ return true;
+ }
+
+ /// Return true if the target has native support for the specified value type
+ /// and it is 'desirable' to use the type for the given node type. e.g. On x86
+ /// i16 is legal, but undesirable since i16 instruction encodings are longer
+ /// and some i16 instructions are slow.
+ virtual bool isTypeDesirableForOp(unsigned /*Opc*/, EVT VT) const {
+ // By default, assume all legal types are desirable.
+ return isTypeLegal(VT);
+ }
+
+ /// Return true if it is profitable for dag combiner to transform a floating
+ /// point op of specified opcode to a equivalent op of an integer
+ /// type. e.g. f32 load -> i32 load can be profitable on ARM.
+ virtual bool isDesirableToTransformToIntegerOp(unsigned /*Opc*/,
+ EVT /*VT*/) const {
+ return false;
+ }
+
+ /// This method query the target whether it is beneficial for dag combiner to
+ /// promote the specified node. If true, it should return the desired
+ /// promotion type by reference.
+ virtual bool IsDesirableToPromoteOp(SDValue /*Op*/, EVT &/*PVT*/) const {
+ return false;
+ }
+
+ //===--------------------------------------------------------------------===//
+ // Lowering methods - These methods must be implemented by targets so that
+ // the SelectionDAGBuilder code knows how to lower these.
+ //
+
+ /// This hook must be implemented to lower the incoming (formal) arguments,
+ /// described by the Ins array, into the specified DAG. The implementation
+ /// should fill in the InVals array with legal-type argument values, and
+ /// return the resulting token chain value.
+ ///
+ virtual SDValue
+ LowerFormalArguments(SDValue /*Chain*/, CallingConv::ID /*CallConv*/,
+ bool /*isVarArg*/,
+ const SmallVectorImpl<ISD::InputArg> &/*Ins*/,
+ SDLoc /*dl*/, SelectionDAG &/*DAG*/,
+ SmallVectorImpl<SDValue> &/*InVals*/) const {
+ llvm_unreachable("Not Implemented");
+ }
+
+ struct ArgListEntry {
+ SDValue Node;
+ Type* Ty;
+ bool isSExt : 1;
+ bool isZExt : 1;
+ bool isInReg : 1;
+ bool isSRet : 1;
+ bool isNest : 1;
+ bool isByVal : 1;
+ bool isInAlloca : 1;
+ bool isReturned : 1;
+ uint16_t Alignment;
+
+ ArgListEntry() : isSExt(false), isZExt(false), isInReg(false),
+ isSRet(false), isNest(false), isByVal(false), isInAlloca(false),
+ isReturned(false), Alignment(0) { }
+
+ void setAttributes(ImmutableCallSite *CS, unsigned AttrIdx);
+ };
+ typedef std::vector<ArgListEntry> ArgListTy;
+
+ /// This structure contains all information that is necessary for lowering
+ /// calls. It is passed to TLI::LowerCallTo when the SelectionDAG builder
+ /// needs to lower a call, and targets will see this struct in their LowerCall
+ /// implementation.
+ struct CallLoweringInfo {
+ SDValue Chain;
+ Type *RetTy;
+ bool RetSExt : 1;
+ bool RetZExt : 1;
+ bool IsVarArg : 1;
+ bool IsInReg : 1;
+ bool DoesNotReturn : 1;
+ bool IsReturnValueUsed : 1;
+
+ // IsTailCall should be modified by implementations of
+ // TargetLowering::LowerCall that perform tail call conversions.
+ bool IsTailCall;
+
+ unsigned NumFixedArgs;
+ CallingConv::ID CallConv;
+ SDValue Callee;
+ ArgListTy Args;
+ SelectionDAG &DAG;
+ SDLoc DL;
+ ImmutableCallSite *CS;
+ bool IsPatchPoint;
+ SmallVector<ISD::OutputArg, 32> Outs;
+ SmallVector<SDValue, 32> OutVals;
+ SmallVector<ISD::InputArg, 32> Ins;
+
+ CallLoweringInfo(SelectionDAG &DAG)
+ : RetTy(nullptr), RetSExt(false), RetZExt(false), IsVarArg(false),
+ IsInReg(false), DoesNotReturn(false), IsReturnValueUsed(true),
+ IsTailCall(false), NumFixedArgs(-1), CallConv(CallingConv::C),
+ DAG(DAG), CS(nullptr), IsPatchPoint(false) {}
+
+ CallLoweringInfo &setDebugLoc(SDLoc dl) {
+ DL = dl;
+ return *this;
+ }
+
+ CallLoweringInfo &setChain(SDValue InChain) {
+ Chain = InChain;
+ return *this;
+ }
+
+ CallLoweringInfo &setCallee(CallingConv::ID CC, Type *ResultType,
+ SDValue Target, ArgListTy &&ArgsList,
+ unsigned FixedArgs = -1) {
+ RetTy = ResultType;
+ Callee = Target;
+ CallConv = CC;
+ NumFixedArgs =
+ (FixedArgs == static_cast<unsigned>(-1) ? Args.size() : FixedArgs);
+ Args = std::move(ArgsList);
+ return *this;
+ }
+
+ CallLoweringInfo &setCallee(Type *ResultType, FunctionType *FTy,
+ SDValue Target, ArgListTy &&ArgsList,
+ ImmutableCallSite &Call) {
+ RetTy = ResultType;
+
+ IsInReg = Call.paramHasAttr(0, Attribute::InReg);
+ DoesNotReturn = Call.doesNotReturn();
+ IsVarArg = FTy->isVarArg();
+ IsReturnValueUsed = !Call.getInstruction()->use_empty();
+ RetSExt = Call.paramHasAttr(0, Attribute::SExt);
+ RetZExt = Call.paramHasAttr(0, Attribute::ZExt);
+
+ Callee = Target;
+
+ CallConv = Call.getCallingConv();
+ NumFixedArgs = FTy->getNumParams();
+ Args = std::move(ArgsList);
+
+ CS = &Call;
+
+ return *this;
+ }
+
+ CallLoweringInfo &setInRegister(bool Value = true) {
+ IsInReg = Value;
+ return *this;
+ }
+
+ CallLoweringInfo &setNoReturn(bool Value = true) {
+ DoesNotReturn = Value;
+ return *this;
+ }
+
+ CallLoweringInfo &setVarArg(bool Value = true) {
+ IsVarArg = Value;
+ return *this;
+ }
+
+ CallLoweringInfo &setTailCall(bool Value = true) {
+ IsTailCall = Value;
+ return *this;
+ }
+
+ CallLoweringInfo &setDiscardResult(bool Value = true) {
+ IsReturnValueUsed = !Value;
+ return *this;
+ }
+
+ CallLoweringInfo &setSExtResult(bool Value = true) {
+ RetSExt = Value;
+ return *this;
+ }
+
+ CallLoweringInfo &setZExtResult(bool Value = true) {
+ RetZExt = Value;
+ return *this;
+ }
+
+ CallLoweringInfo &setIsPatchPoint(bool Value = true) {
+ IsPatchPoint = Value;
+ return *this;
+ }
+
+ ArgListTy &getArgs() {
+ return Args;
+ }
+ };
+
+ /// This function lowers an abstract call to a function into an actual call.
+ /// This returns a pair of operands. The first element is the return value
+ /// for the function (if RetTy is not VoidTy). The second element is the
+ /// outgoing token chain. It calls LowerCall to do the actual lowering.
+ std::pair<SDValue, SDValue> LowerCallTo(CallLoweringInfo &CLI) const;
+
+ /// This hook must be implemented to lower calls into the the specified
+ /// DAG. The outgoing arguments to the call are described by the Outs array,
+ /// and the values to be returned by the call are described by the Ins
+ /// array. The implementation should fill in the InVals array with legal-type
+ /// return values from the call, and return the resulting token chain value.
+ virtual SDValue
+ LowerCall(CallLoweringInfo &/*CLI*/,
+ SmallVectorImpl<SDValue> &/*InVals*/) const {
+ llvm_unreachable("Not Implemented");
+ }
+
+ /// Target-specific cleanup for formal ByVal parameters.
+ virtual void HandleByVal(CCState *, unsigned &, unsigned) const {}
+
+ /// This hook should be implemented to check whether the return values
+ /// described by the Outs array can fit into the return registers. If false
+ /// is returned, an sret-demotion is performed.
+ virtual bool CanLowerReturn(CallingConv::ID /*CallConv*/,
+ MachineFunction &/*MF*/, bool /*isVarArg*/,
+ const SmallVectorImpl<ISD::OutputArg> &/*Outs*/,
+ LLVMContext &/*Context*/) const
+ {
+ // Return true by default to get preexisting behavior.
+ return true;
+ }
+
+ /// This hook must be implemented to lower outgoing return values, described
+ /// by the Outs array, into the specified DAG. The implementation should
+ /// return the resulting token chain value.
+ virtual SDValue
+ LowerReturn(SDValue /*Chain*/, CallingConv::ID /*CallConv*/,
+ bool /*isVarArg*/,
+ const SmallVectorImpl<ISD::OutputArg> &/*Outs*/,
+ const SmallVectorImpl<SDValue> &/*OutVals*/,
+ SDLoc /*dl*/, SelectionDAG &/*DAG*/) const {
+ llvm_unreachable("Not Implemented");
+ }
+
+ /// Return true if result of the specified node is used by a return node
+ /// only. It also compute and return the input chain for the tail call.
+ ///
+ /// This is used to determine whether it is possible to codegen a libcall as
+ /// tail call at legalization time.
+ virtual bool isUsedByReturnOnly(SDNode *, SDValue &/*Chain*/) const {
+ return false;
+ }
+
+ /// Return true if the target may be able emit the call instruction as a tail
+ /// call. This is used by optimization passes to determine if it's profitable
+ /// to duplicate return instructions to enable tailcall optimization.
+ virtual bool mayBeEmittedAsTailCall(CallInst *) const {
+ return false;
+ }
+
+ /// Return the builtin name for the __builtin___clear_cache intrinsic
+ /// Default is to invoke the clear cache library call
+ virtual const char * getClearCacheBuiltinName() const {
+ return "__clear_cache";
+ }
+
+ /// Return the register ID of the name passed in. Used by named register
+ /// global variables extension. There is no target-independent behaviour
+ /// so the default action is to bail.
+ virtual unsigned getRegisterByName(const char* RegName, EVT VT) const {
+ report_fatal_error("Named registers not implemented for this target");
+ }
+
+ /// Return the type that should be used to zero or sign extend a
+ /// zeroext/signext integer argument or return value. FIXME: Most C calling
+ /// convention requires the return type to be promoted, but this is not true
+ /// all the time, e.g. i1 on x86-64. It is also not necessary for non-C
+ /// calling conventions. The frontend should handle this and include all of
+ /// the necessary information.
+ virtual EVT getTypeForExtArgOrReturn(LLVMContext &Context, EVT VT,
+ ISD::NodeType /*ExtendKind*/) const {
+ EVT MinVT = getRegisterType(Context, MVT::i32);
+ return VT.bitsLT(MinVT) ? MinVT : VT;
+ }
+
+ /// For some targets, an LLVM struct type must be broken down into multiple
+ /// simple types, but the calling convention specifies that the entire struct
+ /// must be passed in a block of consecutive registers.
+ virtual bool
+ functionArgumentNeedsConsecutiveRegisters(Type *Ty, CallingConv::ID CallConv,
+ bool isVarArg) const {
+ return false;
+ }
+
+ /// Returns a 0 terminated array of registers that can be safely used as
+ /// scratch registers.
+ virtual const MCPhysReg *getScratchRegisters(CallingConv::ID CC) const {
+ return nullptr;
+ }
+
+ /// This callback is used to prepare for a volatile or atomic load.
+ /// It takes a chain node as input and returns the chain for the load itself.
+ ///
+ /// Having a callback like this is necessary for targets like SystemZ,
+ /// which allows a CPU to reuse the result of a previous load indefinitely,
+ /// even if a cache-coherent store is performed by another CPU. The default
+ /// implementation does nothing.
+ virtual SDValue prepareVolatileOrAtomicLoad(SDValue Chain, SDLoc DL,
+ SelectionDAG &DAG) const {
+ return Chain;
+ }
+
+ /// This callback is invoked by the type legalizer to legalize nodes with an
+ /// illegal operand type but legal result types. It replaces the
+ /// LowerOperation callback in the type Legalizer. The reason we can not do
+ /// away with LowerOperation entirely is that LegalizeDAG isn't yet ready to
+ /// use this callback.
+ ///
+ /// TODO: Consider merging with ReplaceNodeResults.
+ ///
+ /// The target places new result values for the node in Results (their number
+ /// and types must exactly match those of the original return values of
+ /// the node), or leaves Results empty, which indicates that the node is not
+ /// to be custom lowered after all.
+ /// The default implementation calls LowerOperation.
+ virtual void LowerOperationWrapper(SDNode *N,
+ SmallVectorImpl<SDValue> &Results,
+ SelectionDAG &DAG) const;
+
+ /// This callback is invoked for operations that are unsupported by the
+ /// target, which are registered to use 'custom' lowering, and whose defined
+ /// values are all legal. If the target has no operations that require custom
+ /// lowering, it need not implement this. The default implementation of this
+ /// aborts.
+ virtual SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const;
+
+ /// This callback is invoked when a node result type is illegal for the
+ /// target, and the operation was registered to use 'custom' lowering for that
+ /// result type. The target places new result values for the node in Results
+ /// (their number and types must exactly match those of the original return
+ /// values of the node), or leaves Results empty, which indicates that the
+ /// node is not to be custom lowered after all.
+ ///
+ /// If the target has no operations that require custom lowering, it need not
+ /// implement this. The default implementation aborts.
+ virtual void ReplaceNodeResults(SDNode * /*N*/,
+ SmallVectorImpl<SDValue> &/*Results*/,
+ SelectionDAG &/*DAG*/) const {
+ llvm_unreachable("ReplaceNodeResults not implemented for this target!");
+ }
+
+ /// This method returns the name of a target specific DAG node.
+ virtual const char *getTargetNodeName(unsigned Opcode) const;
+
+ /// This method returns a target specific FastISel object, or null if the
+ /// target does not support "fast" ISel.
+ virtual FastISel *createFastISel(FunctionLoweringInfo &,
+ const TargetLibraryInfo *) const {
+ return nullptr;
+ }
+
+
+ bool verifyReturnAddressArgumentIsConstant(SDValue Op,
+ SelectionDAG &DAG) const;
+
+ //===--------------------------------------------------------------------===//
+ // Inline Asm Support hooks
+ //
+
+ /// This hook allows the target to expand an inline asm call to be explicit
+ /// llvm code if it wants to. This is useful for turning simple inline asms
+ /// into LLVM intrinsics, which gives the compiler more information about the
+ /// behavior of the code.
+ virtual bool ExpandInlineAsm(CallInst *) const {
+ return false;
+ }
+
+ enum ConstraintType {
+ C_Register, // Constraint represents specific register(s).
+ C_RegisterClass, // Constraint represents any of register(s) in class.
+ C_Memory, // Memory constraint.
+ C_Other, // Something else.
+ C_Unknown // Unsupported constraint.
+ };
+
+ enum ConstraintWeight {
+ // Generic weights.
+ CW_Invalid = -1, // No match.
+ CW_Okay = 0, // Acceptable.
+ CW_Good = 1, // Good weight.
+ CW_Better = 2, // Better weight.
+ CW_Best = 3, // Best weight.
+
+ // Well-known weights.
+ CW_SpecificReg = CW_Okay, // Specific register operands.
+ CW_Register = CW_Good, // Register operands.
+ CW_Memory = CW_Better, // Memory operands.
+ CW_Constant = CW_Best, // Constant operand.
+ CW_Default = CW_Okay // Default or don't know type.
+ };
+
+ /// This contains information for each constraint that we are lowering.
+ struct AsmOperandInfo : public InlineAsm::ConstraintInfo {
+ /// This contains the actual string for the code, like "m". TargetLowering
+ /// picks the 'best' code from ConstraintInfo::Codes that most closely
+ /// matches the operand.
+ std::string ConstraintCode;
+
+ /// Information about the constraint code, e.g. Register, RegisterClass,
+ /// Memory, Other, Unknown.
+ TargetLowering::ConstraintType ConstraintType;
+
+ /// If this is the result output operand or a clobber, this is null,
+ /// otherwise it is the incoming operand to the CallInst. This gets
+ /// modified as the asm is processed.
+ Value *CallOperandVal;
+
+ /// The ValueType for the operand value.
+ MVT ConstraintVT;
+
+ /// Return true of this is an input operand that is a matching constraint
+ /// like "4".
+ bool isMatchingInputConstraint() const;
+
+ /// If this is an input matching constraint, this method returns the output
+ /// operand it matches.
+ unsigned getMatchedOperand() const;
+
+ /// Copy constructor for copying from a ConstraintInfo.
+ AsmOperandInfo(InlineAsm::ConstraintInfo Info)
+ : InlineAsm::ConstraintInfo(std::move(Info)),
+ ConstraintType(TargetLowering::C_Unknown), CallOperandVal(nullptr),
+ ConstraintVT(MVT::Other) {}
+ };
+
+ typedef std::vector<AsmOperandInfo> AsmOperandInfoVector;
+
+ /// Split up the constraint string from the inline assembly value into the
+ /// specific constraints and their prefixes, and also tie in the associated
+ /// operand values. If this returns an empty vector, and if the constraint
+ /// string itself isn't empty, there was an error parsing.
+ virtual AsmOperandInfoVector ParseConstraints(ImmutableCallSite CS) const;
+
+ /// Examine constraint type and operand type and determine a weight value.
+ /// The operand object must already have been set up with the operand type.
+ virtual ConstraintWeight getMultipleConstraintMatchWeight(
+ AsmOperandInfo &info, int maIndex) const;
+
+ /// Examine constraint string and operand type and determine a weight value.
+ /// The operand object must already have been set up with the operand type.
+ virtual ConstraintWeight getSingleConstraintMatchWeight(
+ AsmOperandInfo &info, const char *constraint) const;
+
+ /// Determines the constraint code and constraint type to use for the specific
+ /// AsmOperandInfo, setting OpInfo.ConstraintCode and OpInfo.ConstraintType.
+ /// If the actual operand being passed in is available, it can be passed in as
+ /// Op, otherwise an empty SDValue can be passed.
+ virtual void ComputeConstraintToUse(AsmOperandInfo &OpInfo,
+ SDValue Op,
+ SelectionDAG *DAG = nullptr) const;
+
+ /// Given a constraint, return the type of constraint it is for this target.
+ virtual ConstraintType getConstraintType(const std::string &Constraint) const;
+
+ /// Given a physical register constraint (e.g. {edx}), return the register
+ /// number and the register class for the register.
+ ///
+ /// Given a register class constraint, like 'r', if this corresponds directly
+ /// to an LLVM register class, return a register of 0 and the register class
+ /// pointer.
+ ///
+ /// This should only be used for C_Register constraints. On error, this
+ /// returns a register number of 0 and a null register class pointer..
+ virtual std::pair<unsigned, const TargetRegisterClass*>
+ getRegForInlineAsmConstraint(const std::string &Constraint,
+ MVT VT) const;
+
+ /// Try to replace an X constraint, which matches anything, with another that
+ /// has more specific requirements based on the type of the corresponding
+ /// operand. This returns null if there is no replacement to make.
+ virtual const char *LowerXConstraint(EVT ConstraintVT) const;
+
+ /// Lower the specified operand into the Ops vector. If it is invalid, don't
+ /// add anything to Ops.
+ virtual void LowerAsmOperandForConstraint(SDValue Op, std::string &Constraint,
+ std::vector<SDValue> &Ops,
+ SelectionDAG &DAG) const;
+
+ //===--------------------------------------------------------------------===//
+ // Div utility functions
+ //
+ SDValue BuildExactSDIV(SDValue Op1, SDValue Op2, SDLoc dl,
+ SelectionDAG &DAG) const;
+ SDValue BuildSDIV(SDNode *N, const APInt &Divisor, SelectionDAG &DAG,
+ bool IsAfterLegalization,
+ std::vector<SDNode *> *Created) const;
+ SDValue BuildUDIV(SDNode *N, const APInt &Divisor, SelectionDAG &DAG,
+ bool IsAfterLegalization,
+ std::vector<SDNode *> *Created) const;
+ virtual SDValue BuildSDIVPow2(SDNode *N, const APInt &Divisor,
+ SelectionDAG &DAG,
+ std::vector<SDNode *> *Created) const {
+ return SDValue();
+ }
+
+ /// Indicate whether this target prefers to combine the given number of FDIVs
+ /// with the same divisor.
+ virtual bool combineRepeatedFPDivisors(unsigned NumUsers) const {
+ return false;
+ }
+
+ /// Hooks for building estimates in place of slower divisions and square
+ /// roots.
+
+ /// Return a reciprocal square root estimate value for the input operand.
+ /// The RefinementSteps output is the number of Newton-Raphson refinement
+ /// iterations required to generate a sufficient (though not necessarily
+ /// IEEE-754 compliant) estimate for the value type.
+ /// The boolean UseOneConstNR output is used to select a Newton-Raphson
+ /// algorithm implementation that uses one constant or two constants.
+ /// A target may choose to implement its own refinement within this function.
+ /// If that's true, then return '0' as the number of RefinementSteps to avoid
+ /// any further refinement of the estimate.
+ /// An empty SDValue return means no estimate sequence can be created.
+ virtual SDValue getRsqrtEstimate(SDValue Operand,
+ DAGCombinerInfo &DCI,
+ unsigned &RefinementSteps,
+ bool &UseOneConstNR) const {
+ return SDValue();
+ }
+
+ /// Return a reciprocal estimate value for the input operand.
+ /// The RefinementSteps output is the number of Newton-Raphson refinement
+ /// iterations required to generate a sufficient (though not necessarily
+ /// IEEE-754 compliant) estimate for the value type.
+ /// A target may choose to implement its own refinement within this function.
+ /// If that's true, then return '0' as the number of RefinementSteps to avoid
+ /// any further refinement of the estimate.
+ /// An empty SDValue return means no estimate sequence can be created.
+ virtual SDValue getRecipEstimate(SDValue Operand,
+ DAGCombinerInfo &DCI,
+ unsigned &RefinementSteps) const {
+ return SDValue();
+ }
+
+ //===--------------------------------------------------------------------===//
+ // Legalization utility functions
+ //
+
+ /// Expand a MUL into two nodes. One that computes the high bits of
+ /// the result and one that computes the low bits.
+ /// \param HiLoVT The value type to use for the Lo and Hi nodes.
+ /// \param LL Low bits of the LHS of the MUL. You can use this parameter
+ /// if you want to control how low bits are extracted from the LHS.
+ /// \param LH High bits of the LHS of the MUL. See LL for meaning.
+ /// \param RL Low bits of the RHS of the MUL. See LL for meaning
+ /// \param RH High bits of the RHS of the MUL. See LL for meaning.
+ /// \returns true if the node has been expanded. false if it has not
+ bool expandMUL(SDNode *N, SDValue &Lo, SDValue &Hi, EVT HiLoVT,
+ SelectionDAG &DAG, SDValue LL = SDValue(),
+ SDValue LH = SDValue(), SDValue RL = SDValue(),
+ SDValue RH = SDValue()) const;
+
+ /// Expand float(f32) to SINT(i64) conversion
+ /// \param N Node to expand
+ /// \param Result output after conversion
+ /// \returns True, if the expansion was successful, false otherwise
+ bool expandFP_TO_SINT(SDNode *N, SDValue &Result, SelectionDAG &DAG) const;
+
+ //===--------------------------------------------------------------------===//
+ // Instruction Emitting Hooks
+ //
+
+ /// This method should be implemented by targets that mark instructions with
+ /// the 'usesCustomInserter' flag. These instructions are special in various
+ /// ways, which require special support to insert. The specified MachineInstr
+ /// is created but not inserted into any basic blocks, and this method is
+ /// called to expand it into a sequence of instructions, potentially also
+ /// creating new basic blocks and control flow.
+ virtual MachineBasicBlock *
+ EmitInstrWithCustomInserter(MachineInstr *MI, MachineBasicBlock *MBB) const;
+
+ /// This method should be implemented by targets that mark instructions with
+ /// the 'hasPostISelHook' flag. These instructions must be adjusted after
+ /// instruction selection by target hooks. e.g. To fill in optional defs for
+ /// ARM 's' setting instructions.
+ virtual void
+ AdjustInstrPostInstrSelection(MachineInstr *MI, SDNode *Node) const;
+
+ /// If this function returns true, SelectionDAGBuilder emits a
+ /// LOAD_STACK_GUARD node when it is lowering Intrinsic::stackprotector.
+ virtual bool useLoadStackGuardNode() const {
+ return false;
+ }
};
-/// GetReturnInfo - Given an LLVM IR type and return type attributes,
-/// compute the return value EVTs and flags, and optionally also
-/// the offsets, if the return value is being lowered to memory.
-void GetReturnInfo(Type* ReturnType, Attribute attr,
+/// Given an LLVM IR type and return type attributes, compute the return value
+/// EVTs and flags, and optionally also the offsets, if the return value is
+/// being lowered to memory.
+void GetReturnInfo(Type* ReturnType, AttributeSet attr,
SmallVectorImpl<ISD::OutputArg> &Outs,
const TargetLowering &TLI);