diff options
Diffstat (limited to 'include/llvm/Target/TargetLowering.h')
| -rw-r--r-- | include/llvm/Target/TargetLowering.h | 295 |
1 files changed, 198 insertions, 97 deletions
diff --git a/include/llvm/Target/TargetLowering.h b/include/llvm/Target/TargetLowering.h index 17d761c..3e36fb7 100644 --- a/include/llvm/Target/TargetLowering.h +++ b/include/llvm/Target/TargetLowering.h @@ -94,6 +94,19 @@ public: Custom // Use the LowerOperation hook to implement custom lowering. }; + /// LegalizeAction - 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. + TypeExpandInteger, // Split this integer into two of half the size. + TypeSoftenFloat, // Convert this float to a same size integer type. + TypeExpandFloat, // Split this float into two of half the size. + TypeScalarizeVector, // Replace this one-element vector with its element. + TypeSplitVector, // Split this vector into two of half the size. + TypeWidenVector // This vector should be widened into a larger vector. + }; + enum BooleanContent { // How the target represents true/false values. UndefinedBooleanContent, // Only bit 0 counts, the rest can hold garbage. ZeroOrOneBooleanContent, // All bits zero except for bit 0. @@ -200,71 +213,20 @@ public: } class ValueTypeActionImpl { - /// ValueTypeActions - For each value type, keep a LegalizeAction enum + /// ValueTypeActions - For each value type, keep a LegalizeTypeAction enum /// that indicates how instruction selection should deal with the type. uint8_t ValueTypeActions[MVT::LAST_VALUETYPE]; - LegalizeAction getExtendedTypeAction(EVT VT) const { - // Handle non-vector integers. - if (!VT.isVector()) { - assert(VT.isInteger() && "Unsupported extended type!"); - unsigned BitSize = VT.getSizeInBits(); - // First promote to a power-of-two size, then expand if necessary. - if (BitSize < 8 || !isPowerOf2_32(BitSize)) - return Promote; - return Expand; - } - - // Vectors with only one element are always scalarized. - if (VT.getVectorNumElements() == 1) - return Expand; - - // Vectors with a number of elements that is not a power of two are always - // widened, for example <3 x float> -> <4 x float>. - if (!VT.isPow2VectorType()) - return Promote; - - // Vectors with a crazy element type are always expanded, for example - // <4 x i2> is expanded into two vectors of type <2 x i2>. - if (!VT.getVectorElementType().isSimple()) - return Expand; - - // If this type is smaller than a legal vector type then widen it, - // otherwise expand it. E.g. <2 x float> -> <4 x float>. - MVT EltType = VT.getVectorElementType().getSimpleVT(); - unsigned NumElts = VT.getVectorNumElements(); - while (1) { - // Round up to the next power of 2. - NumElts = (unsigned)NextPowerOf2(NumElts); - - // If there is no simple vector type with this many elements then there - // cannot be a larger legal vector type. Note that this assumes that - // there are no skipped intermediate vector types in the simple types. - MVT LargerVector = MVT::getVectorVT(EltType, NumElts); - if (LargerVector == MVT()) - return Expand; - - // If this type is legal then widen the vector. - if (getTypeAction(LargerVector) == Legal) - return Promote; - } - } public: ValueTypeActionImpl() { std::fill(ValueTypeActions, array_endof(ValueTypeActions), 0); } - LegalizeAction getTypeAction(EVT VT) const { - if (!VT.isExtended()) - return getTypeAction(VT.getSimpleVT()); - return getExtendedTypeAction(VT); - } - - LegalizeAction getTypeAction(MVT VT) const { - return (LegalizeAction)ValueTypeActions[VT.SimpleTy]; + LegalizeTypeAction getTypeAction(MVT VT) const { + return (LegalizeTypeAction)ValueTypeActions[VT.SimpleTy]; } - void setTypeAction(EVT VT, LegalizeAction Action) { + void setTypeAction(EVT VT, LegalizeTypeAction Action) { unsigned I = VT.getSimpleVT().SimpleTy; ValueTypeActions[I] = Action; } @@ -278,10 +240,10 @@ public: /// 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. - LegalizeAction getTypeAction(EVT VT) const { - return ValueTypeActions.getTypeAction(VT); + LegalizeTypeAction getTypeAction(LLVMContext &Context, EVT VT) const { + return getTypeConversion(Context, VT).first; } - LegalizeAction getTypeAction(MVT VT) const { + LegalizeTypeAction getTypeAction(MVT VT) const { return ValueTypeActions.getTypeAction(VT); } @@ -292,38 +254,7 @@ public: /// 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 { - if (VT.isSimple()) { - assert((unsigned)VT.getSimpleVT().SimpleTy < - array_lengthof(TransformToType)); - EVT NVT = TransformToType[VT.getSimpleVT().SimpleTy]; - assert(getTypeAction(NVT) != Promote && - "Promote may not follow Expand or Promote"); - return NVT; - } - - if (VT.isVector()) { - EVT NVT = VT.getPow2VectorType(Context); - if (NVT == VT) { - // Vector length is a power of 2 - split to half the size. - unsigned NumElts = VT.getVectorNumElements(); - EVT EltVT = VT.getVectorElementType(); - return (NumElts == 1) ? - EltVT : EVT::getVectorVT(Context, EltVT, NumElts / 2); - } - // Promote to a power of two size, avoiding multi-step promotion. - return getTypeAction(NVT) == Promote ? - getTypeToTransformTo(Context, NVT) : NVT; - } else if (VT.isInteger()) { - EVT NVT = VT.getRoundIntegerType(Context); - if (NVT == VT) // Size is a power of two - expand to half the size. - return EVT::getIntegerVT(Context, VT.getSizeInBits() / 2); - - // Promote to a power of two size, avoiding multi-step promotion. - return getTypeAction(NVT) == Promote ? - getTypeToTransformTo(Context, NVT) : NVT; - } - assert(0 && "Unsupported extended type!"); - return MVT(MVT::Other); // Not reached + return getTypeConversion(Context, VT).second; } /// getTypeToExpandTo - For types supported by the target, this is an @@ -333,7 +264,7 @@ public: EVT getTypeToExpandTo(LLVMContext &Context, EVT VT) const { assert(!VT.isVector()); while (true) { - switch (getTypeAction(VT)) { + switch (getTypeAction(Context, VT)) { case Legal: return VT; case Expand: @@ -761,6 +692,18 @@ public: return MinStackArgumentAlignment; } + /// getMinFunctionAlignment - return the minimum function alignment. + /// + unsigned getMinFunctionAlignment() const { + return MinFunctionAlignment; + } + + /// getPrefFunctionAlignment - return the preferred function alignment. + /// + unsigned getPrefFunctionAlignment() const { + return PrefFunctionAlignment; + } + /// getPrefLoopAlignment - return the preferred loop alignment. /// unsigned getPrefLoopAlignment() const { @@ -824,9 +767,6 @@ public: /// PIC relocation models. virtual bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const; - /// getFunctionAlignment - Return the Log2 alignment of this function. - virtual unsigned getFunctionAlignment(const Function *) const = 0; - /// 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 @@ -1167,6 +1107,18 @@ protected: JumpBufAlignment = Align; } + /// setMinFunctionAlignment - Set the target's minimum function alignment. + 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 + 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. void setPrefLoopAlignment(unsigned Align) { @@ -1259,7 +1211,8 @@ public: /// 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, bool isVarArg, + virtual bool CanLowerReturn(CallingConv::ID CallConv, + MachineFunction &MF, bool isVarArg, const SmallVectorImpl<ISD::OutputArg> &Outs, LLVMContext &Context) const { @@ -1497,7 +1450,7 @@ public: /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops /// vector. If it is invalid, don't add anything to Ops. - virtual void LowerAsmOperandForConstraint(SDValue Op, char ConstraintLetter, + virtual void LowerAsmOperandForConstraint(SDValue Op, std::string &Constraint, std::vector<SDValue> &Ops, SelectionDAG &DAG) const; @@ -1583,6 +1536,14 @@ public: 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 Imm) const { + return true; + } + //===--------------------------------------------------------------------===// // Div utility functions // @@ -1637,6 +1598,13 @@ private: const TargetData *TD; const TargetLoweringObjectFile &TLOF; + /// We are in the process of implementing a new TypeLegalization action + /// which is the promotion of vector elements. This feature is under + /// development. Until this feature is complete, it is only enabled using a + /// flag. We pass this flag using a member because of circular dep issues. + /// This member will be removed with the flag once we complete the transition. + bool mayPromoteElements; + /// PointerTy - The type to use for pointers, usually i32 or i64. /// MVT PointerTy; @@ -1693,7 +1661,18 @@ private: /// unsigned MinStackArgumentAlignment; - /// PrefLoopAlignment - The perferred loop alignment. + /// MinFunctionAlignment - 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). + /// + unsigned PrefFunctionAlignment; + + /// PrefLoopAlignment - The preferred loop alignment. /// unsigned PrefLoopAlignment; @@ -1774,6 +1753,128 @@ private: ValueTypeActionImpl ValueTypeActions; + typedef std::pair<LegalizeTypeAction, EVT> LegalizeKind; + + LegalizeKind + getTypeConversion(LLVMContext &Context, EVT VT) const { + // If this is a simple type, use the ComputeRegisterProp mechanism. + if (VT.isSimple()) { + assert((unsigned)VT.getSimpleVT().SimpleTy < + array_lengthof(TransformToType)); + EVT NVT = TransformToType[VT.getSimpleVT().SimpleTy]; + LegalizeTypeAction LA = ValueTypeActions.getTypeAction(VT.getSimpleVT()); + + assert( + (!(NVT.isSimple() && LA != TypeLegal) || + ValueTypeActions.getTypeAction(NVT.getSimpleVT()) != TypePromoteInteger) + && "Promote may not follow Expand or Promote"); + + return LegalizeKind(LA, NVT); + } + + // Handle Extended Scalar Types. + if (!VT.isVector()) { + assert(VT.isInteger() && "Float types must be simple"); + unsigned BitSize = VT.getSizeInBits(); + // First promote to a power-of-two size, then expand if necessary. + if (BitSize < 8 || !isPowerOf2_32(BitSize)) { + EVT NVT = VT.getRoundIntegerType(Context); + assert(NVT != VT && "Unable to round integer VT"); + LegalizeKind NextStep = getTypeConversion(Context, NVT); + // Avoid multi-step promotion. + if (NextStep.first == TypePromoteInteger) return NextStep; + // Return rounded integer type. + return LegalizeKind(TypePromoteInteger, NVT); + } + + return LegalizeKind(TypeExpandInteger, + EVT::getIntegerVT(Context, VT.getSizeInBits()/2)); + } + + // Handle vector types. + unsigned NumElts = VT.getVectorNumElements(); + EVT EltVT = VT.getVectorElementType(); + + // Vectors with only one element are always scalarized. + if (NumElts == 1) + return LegalizeKind(TypeScalarizeVector, EltVT); + + // If we allow the promotion of vector elements using a flag, + // then try to widen vector elements until a legal type is found. + if (mayPromoteElements && 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>. + if (!VT.isPow2VectorType()) { + NumElts = (unsigned)NextPowerOf2(NumElts); + EVT NVT = EVT::getVectorVT(Context, EltVT, NumElts); + return LegalizeKind(TypeWidenVector, NVT); + } + + // Examine the element type. + LegalizeKind LK = getTypeConversion(Context, EltVT); + + // If type is to be expanded, split the vector. + // <4 x i140> -> <2 x i140> + if (LK.first == TypeExpandInteger) + return LegalizeKind(TypeSplitVector, + EVT::getVectorVT(Context, EltVT, NumElts / 2)); + + // Promote the integer element types until a legal vector type is found + // 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. + while (1) { + // Increase the bitwidth of the element to the next pow-of-two + // (which is greater than 8 bits). + EltVT = EVT::getIntegerVT(Context, 1 + EltVT.getSizeInBits() + ).getRoundIntegerType(Context); + + // 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. + if (!EltVT.isSimple()) break; + + // Build a new vector type and check if it is legal. + MVT NVT = MVT::getVectorVT(EltVT.getSimpleVT(), NumElts); + + // Found a legal promoted vector type. + if (ValueTypeActions.getTypeAction(NVT) == TypeLegal) + return LegalizeKind(TypePromoteInteger, + EVT::getVectorVT(Context, EltVT, NumElts)); + } + } + + // Try to widen the vector until a legal type is found. + // If there is no wider legal type, split the vector. + while (1) { + // Round up to the next power of 2. + NumElts = (unsigned)NextPowerOf2(NumElts); + + // If there is no simple vector type with this many elements then there + // cannot be a larger legal vector type. Note that this assumes that + // there are no skipped intermediate vector types in the simple types. + MVT LargerVector = MVT::getVectorVT(EltVT.getSimpleVT(), NumElts); + if (LargerVector == MVT()) break; + + // If this type is legal then widen the vector. + if (ValueTypeActions.getTypeAction(LargerVector) == TypeLegal) + return LegalizeKind(TypeWidenVector, LargerVector); + } + + // Widen odd vectors to next power of two. + if (!VT.isPow2VectorType()) { + EVT NVT = VT.getPow2VectorType(Context); + return LegalizeKind(TypeWidenVector, NVT); + } + + // Vectors with illegal element types are expanded. + EVT NVT = EVT::getVectorVT(Context, EltVT, VT.getVectorNumElements() / 2); + return LegalizeKind(TypeSplitVector, NVT); + + assert(false && "Unable to handle this kind of vector type"); + return LegalizeKind(TypeLegal, VT); + } + std::vector<std::pair<EVT, TargetRegisterClass*> > AvailableRegClasses; /// TargetDAGCombineArray - Targets can specify ISD nodes that they would |
