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Diffstat (limited to 'clang-r353983/include/llvm/CodeGen/MachineFrameInfo.h')
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diff --git a/clang-r353983/include/llvm/CodeGen/MachineFrameInfo.h b/clang-r353983/include/llvm/CodeGen/MachineFrameInfo.h new file mode 100644 index 00000000..402a2dc6 --- /dev/null +++ b/clang-r353983/include/llvm/CodeGen/MachineFrameInfo.h @@ -0,0 +1,787 @@ +//===-- CodeGen/MachineFrameInfo.h - Abstract Stack Frame Rep. --*- C++ -*-===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// The file defines the MachineFrameInfo class. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_CODEGEN_MACHINEFRAMEINFO_H +#define LLVM_CODEGEN_MACHINEFRAMEINFO_H + +#include "llvm/ADT/SmallVector.h" +#include "llvm/Support/DataTypes.h" +#include <cassert> +#include <vector> + +namespace llvm { +class raw_ostream; +class MachineFunction; +class MachineBasicBlock; +class BitVector; +class AllocaInst; + +/// The CalleeSavedInfo class tracks the information need to locate where a +/// callee saved register is in the current frame. +/// Callee saved reg can also be saved to a different register rather than +/// on the stack by setting DstReg instead of FrameIdx. +class CalleeSavedInfo { + unsigned Reg; + union { + int FrameIdx; + unsigned DstReg; + }; + /// Flag indicating whether the register is actually restored in the epilog. + /// In most cases, if a register is saved, it is also restored. There are + /// some situations, though, when this is not the case. For example, the + /// LR register on ARM is usually saved, but on exit from the function its + /// saved value may be loaded directly into PC. Since liveness tracking of + /// physical registers treats callee-saved registers are live outside of + /// the function, LR would be treated as live-on-exit, even though in these + /// scenarios it is not. This flag is added to indicate that the saved + /// register described by this object is not restored in the epilog. + /// The long-term solution is to model the liveness of callee-saved registers + /// by implicit uses on the return instructions, however, the required + /// changes in the ARM backend would be quite extensive. + bool Restored; + /// Flag indicating whether the register is spilled to stack or another + /// register. + bool SpilledToReg; + +public: + explicit CalleeSavedInfo(unsigned R, int FI = 0) + : Reg(R), FrameIdx(FI), Restored(true), SpilledToReg(false) {} + + // Accessors. + unsigned getReg() const { return Reg; } + int getFrameIdx() const { return FrameIdx; } + unsigned getDstReg() const { return DstReg; } + void setFrameIdx(int FI) { + FrameIdx = FI; + SpilledToReg = false; + } + void setDstReg(unsigned SpillReg) { + DstReg = SpillReg; + SpilledToReg = true; + } + bool isRestored() const { return Restored; } + void setRestored(bool R) { Restored = R; } + bool isSpilledToReg() const { return SpilledToReg; } +}; + +/// The MachineFrameInfo class represents an abstract stack frame until +/// prolog/epilog code is inserted. This class is key to allowing stack frame +/// representation optimizations, such as frame pointer elimination. It also +/// allows more mundane (but still important) optimizations, such as reordering +/// of abstract objects on the stack frame. +/// +/// To support this, the class assigns unique integer identifiers to stack +/// objects requested clients. These identifiers are negative integers for +/// fixed stack objects (such as arguments passed on the stack) or nonnegative +/// for objects that may be reordered. Instructions which refer to stack +/// objects use a special MO_FrameIndex operand to represent these frame +/// indexes. +/// +/// Because this class keeps track of all references to the stack frame, it +/// knows when a variable sized object is allocated on the stack. This is the +/// sole condition which prevents frame pointer elimination, which is an +/// important optimization on register-poor architectures. Because original +/// variable sized alloca's in the source program are the only source of +/// variable sized stack objects, it is safe to decide whether there will be +/// any variable sized objects before all stack objects are known (for +/// example, register allocator spill code never needs variable sized +/// objects). +/// +/// When prolog/epilog code emission is performed, the final stack frame is +/// built and the machine instructions are modified to refer to the actual +/// stack offsets of the object, eliminating all MO_FrameIndex operands from +/// the program. +/// +/// Abstract Stack Frame Information +class MachineFrameInfo { +public: + /// Stack Smashing Protection (SSP) rules require that vulnerable stack + /// allocations are located close the stack protector. + enum SSPLayoutKind { + SSPLK_None, ///< Did not trigger a stack protector. No effect on data + ///< layout. + SSPLK_LargeArray, ///< Array or nested array >= SSP-buffer-size. Closest + ///< to the stack protector. + SSPLK_SmallArray, ///< Array or nested array < SSP-buffer-size. 2nd closest + ///< to the stack protector. + SSPLK_AddrOf ///< The address of this allocation is exposed and + ///< triggered protection. 3rd closest to the protector. + }; + +private: + // Represent a single object allocated on the stack. + struct StackObject { + // The offset of this object from the stack pointer on entry to + // the function. This field has no meaning for a variable sized element. + int64_t SPOffset; + + // The size of this object on the stack. 0 means a variable sized object, + // ~0ULL means a dead object. + uint64_t Size; + + // The required alignment of this stack slot. + unsigned Alignment; + + // If true, the value of the stack object is set before + // entering the function and is not modified inside the function. By + // default, fixed objects are immutable unless marked otherwise. + bool isImmutable; + + // If true the stack object is used as spill slot. It + // cannot alias any other memory objects. + bool isSpillSlot; + + /// If true, this stack slot is used to spill a value (could be deopt + /// and/or GC related) over a statepoint. We know that the address of the + /// slot can't alias any LLVM IR value. This is very similar to a Spill + /// Slot, but is created by statepoint lowering is SelectionDAG, not the + /// register allocator. + bool isStatepointSpillSlot = false; + + /// Identifier for stack memory type analagous to address space. If this is + /// non-0, the meaning is target defined. Offsets cannot be directly + /// compared between objects with different stack IDs. The object may not + /// necessarily reside in the same contiguous memory block as other stack + /// objects. Objects with differing stack IDs should not be merged or + /// replaced substituted for each other. + // + /// It is assumed a target uses consecutive, increasing stack IDs starting + /// from 1. + uint8_t StackID; + + /// If this stack object is originated from an Alloca instruction + /// this value saves the original IR allocation. Can be NULL. + const AllocaInst *Alloca; + + // If true, the object was mapped into the local frame + // block and doesn't need additional handling for allocation beyond that. + bool PreAllocated = false; + + // If true, an LLVM IR value might point to this object. + // Normally, spill slots and fixed-offset objects don't alias IR-accessible + // objects, but there are exceptions (on PowerPC, for example, some byval + // arguments have ABI-prescribed offsets). + bool isAliased; + + /// If true, the object has been zero-extended. + bool isZExt = false; + + /// If true, the object has been zero-extended. + bool isSExt = false; + + uint8_t SSPLayout; + + StackObject(uint64_t Size, unsigned Alignment, int64_t SPOffset, + bool IsImmutable, bool IsSpillSlot, const AllocaInst *Alloca, + bool IsAliased, uint8_t StackID = 0) + : SPOffset(SPOffset), Size(Size), Alignment(Alignment), + isImmutable(IsImmutable), isSpillSlot(IsSpillSlot), + StackID(StackID), Alloca(Alloca), isAliased(IsAliased), + SSPLayout(SSPLK_None) {} + }; + + /// The alignment of the stack. + unsigned StackAlignment; + + /// Can the stack be realigned. This can be false if the target does not + /// support stack realignment, or if the user asks us not to realign the + /// stack. In this situation, overaligned allocas are all treated as dynamic + /// allocations and the target must handle them as part of DYNAMIC_STACKALLOC + /// lowering. All non-alloca stack objects have their alignment clamped to the + /// base ABI stack alignment. + /// FIXME: There is room for improvement in this case, in terms of + /// grouping overaligned allocas into a "secondary stack frame" and + /// then only use a single alloca to allocate this frame and only a + /// single virtual register to access it. Currently, without such an + /// optimization, each such alloca gets its own dynamic realignment. + bool StackRealignable; + + /// Whether the function has the \c alignstack attribute. + bool ForcedRealign; + + /// The list of stack objects allocated. + std::vector<StackObject> Objects; + + /// This contains the number of fixed objects contained on + /// the stack. Because fixed objects are stored at a negative index in the + /// Objects list, this is also the index to the 0th object in the list. + unsigned NumFixedObjects = 0; + + /// This boolean keeps track of whether any variable + /// sized objects have been allocated yet. + bool HasVarSizedObjects = false; + + /// This boolean keeps track of whether there is a call + /// to builtin \@llvm.frameaddress. + bool FrameAddressTaken = false; + + /// This boolean keeps track of whether there is a call + /// to builtin \@llvm.returnaddress. + bool ReturnAddressTaken = false; + + /// This boolean keeps track of whether there is a call + /// to builtin \@llvm.experimental.stackmap. + bool HasStackMap = false; + + /// This boolean keeps track of whether there is a call + /// to builtin \@llvm.experimental.patchpoint. + bool HasPatchPoint = false; + + /// The prolog/epilog code inserter calculates the final stack + /// offsets for all of the fixed size objects, updating the Objects list + /// above. It then updates StackSize to contain the number of bytes that need + /// to be allocated on entry to the function. + uint64_t StackSize = 0; + + /// The amount that a frame offset needs to be adjusted to + /// have the actual offset from the stack/frame pointer. The exact usage of + /// this is target-dependent, but it is typically used to adjust between + /// SP-relative and FP-relative offsets. E.G., if objects are accessed via + /// SP then OffsetAdjustment is zero; if FP is used, OffsetAdjustment is set + /// to the distance between the initial SP and the value in FP. For many + /// targets, this value is only used when generating debug info (via + /// TargetRegisterInfo::getFrameIndexReference); when generating code, the + /// corresponding adjustments are performed directly. + int OffsetAdjustment = 0; + + /// The prolog/epilog code inserter may process objects that require greater + /// alignment than the default alignment the target provides. + /// To handle this, MaxAlignment is set to the maximum alignment + /// needed by the objects on the current frame. If this is greater than the + /// native alignment maintained by the compiler, dynamic alignment code will + /// be needed. + /// + unsigned MaxAlignment = 0; + + /// Set to true if this function adjusts the stack -- e.g., + /// when calling another function. This is only valid during and after + /// prolog/epilog code insertion. + bool AdjustsStack = false; + + /// Set to true if this function has any function calls. + bool HasCalls = false; + + /// The frame index for the stack protector. + int StackProtectorIdx = -1; + + /// The frame index for the function context. Used for SjLj exceptions. + int FunctionContextIdx = -1; + + /// This contains the size of the largest call frame if the target uses frame + /// setup/destroy pseudo instructions (as defined in the TargetFrameInfo + /// class). This information is important for frame pointer elimination. + /// It is only valid during and after prolog/epilog code insertion. + unsigned MaxCallFrameSize = ~0u; + + /// The number of bytes of callee saved registers that the target wants to + /// report for the current function in the CodeView S_FRAMEPROC record. + unsigned CVBytesOfCalleeSavedRegisters = 0; + + /// The prolog/epilog code inserter fills in this vector with each + /// callee saved register saved in either the frame or a different + /// register. Beyond its use by the prolog/ epilog code inserter, + /// this data is used for debug info and exception handling. + std::vector<CalleeSavedInfo> CSInfo; + + /// Has CSInfo been set yet? + bool CSIValid = false; + + /// References to frame indices which are mapped + /// into the local frame allocation block. <FrameIdx, LocalOffset> + SmallVector<std::pair<int, int64_t>, 32> LocalFrameObjects; + + /// Size of the pre-allocated local frame block. + int64_t LocalFrameSize = 0; + + /// Required alignment of the local object blob, which is the strictest + /// alignment of any object in it. + unsigned LocalFrameMaxAlign = 0; + + /// Whether the local object blob needs to be allocated together. If not, + /// PEI should ignore the isPreAllocated flags on the stack objects and + /// just allocate them normally. + bool UseLocalStackAllocationBlock = false; + + /// True if the function dynamically adjusts the stack pointer through some + /// opaque mechanism like inline assembly or Win32 EH. + bool HasOpaqueSPAdjustment = false; + + /// True if the function contains operations which will lower down to + /// instructions which manipulate the stack pointer. + bool HasCopyImplyingStackAdjustment = false; + + /// True if the function contains a call to the llvm.vastart intrinsic. + bool HasVAStart = false; + + /// True if this is a varargs function that contains a musttail call. + bool HasMustTailInVarArgFunc = false; + + /// True if this function contains a tail call. If so immutable objects like + /// function arguments are no longer so. A tail call *can* override fixed + /// stack objects like arguments so we can't treat them as immutable. + bool HasTailCall = false; + + /// Not null, if shrink-wrapping found a better place for the prologue. + MachineBasicBlock *Save = nullptr; + /// Not null, if shrink-wrapping found a better place for the epilogue. + MachineBasicBlock *Restore = nullptr; + +public: + explicit MachineFrameInfo(unsigned StackAlignment, bool StackRealignable, + bool ForcedRealign) + : StackAlignment(StackAlignment), StackRealignable(StackRealignable), + ForcedRealign(ForcedRealign) {} + + /// Return true if there are any stack objects in this function. + bool hasStackObjects() const { return !Objects.empty(); } + + /// This method may be called any time after instruction + /// selection is complete to determine if the stack frame for this function + /// contains any variable sized objects. + bool hasVarSizedObjects() const { return HasVarSizedObjects; } + + /// Return the index for the stack protector object. + int getStackProtectorIndex() const { return StackProtectorIdx; } + void setStackProtectorIndex(int I) { StackProtectorIdx = I; } + bool hasStackProtectorIndex() const { return StackProtectorIdx != -1; } + + /// Return the index for the function context object. + /// This object is used for SjLj exceptions. + int getFunctionContextIndex() const { return FunctionContextIdx; } + void setFunctionContextIndex(int I) { FunctionContextIdx = I; } + + /// This method may be called any time after instruction + /// selection is complete to determine if there is a call to + /// \@llvm.frameaddress in this function. + bool isFrameAddressTaken() const { return FrameAddressTaken; } + void setFrameAddressIsTaken(bool T) { FrameAddressTaken = T; } + + /// This method may be called any time after + /// instruction selection is complete to determine if there is a call to + /// \@llvm.returnaddress in this function. + bool isReturnAddressTaken() const { return ReturnAddressTaken; } + void setReturnAddressIsTaken(bool s) { ReturnAddressTaken = s; } + + /// This method may be called any time after instruction + /// selection is complete to determine if there is a call to builtin + /// \@llvm.experimental.stackmap. + bool hasStackMap() const { return HasStackMap; } + void setHasStackMap(bool s = true) { HasStackMap = s; } + + /// This method may be called any time after instruction + /// selection is complete to determine if there is a call to builtin + /// \@llvm.experimental.patchpoint. + bool hasPatchPoint() const { return HasPatchPoint; } + void setHasPatchPoint(bool s = true) { HasPatchPoint = s; } + + /// Return the minimum frame object index. + int getObjectIndexBegin() const { return -NumFixedObjects; } + + /// Return one past the maximum frame object index. + int getObjectIndexEnd() const { return (int)Objects.size()-NumFixedObjects; } + + /// Return the number of fixed objects. + unsigned getNumFixedObjects() const { return NumFixedObjects; } + + /// Return the number of objects. + unsigned getNumObjects() const { return Objects.size(); } + + /// Map a frame index into the local object block + void mapLocalFrameObject(int ObjectIndex, int64_t Offset) { + LocalFrameObjects.push_back(std::pair<int, int64_t>(ObjectIndex, Offset)); + Objects[ObjectIndex + NumFixedObjects].PreAllocated = true; + } + + /// Get the local offset mapping for a for an object. + std::pair<int, int64_t> getLocalFrameObjectMap(int i) const { + assert (i >= 0 && (unsigned)i < LocalFrameObjects.size() && + "Invalid local object reference!"); + return LocalFrameObjects[i]; + } + + /// Return the number of objects allocated into the local object block. + int64_t getLocalFrameObjectCount() const { return LocalFrameObjects.size(); } + + /// Set the size of the local object blob. + void setLocalFrameSize(int64_t sz) { LocalFrameSize = sz; } + + /// Get the size of the local object blob. + int64_t getLocalFrameSize() const { return LocalFrameSize; } + + /// Required alignment of the local object blob, + /// which is the strictest alignment of any object in it. + void setLocalFrameMaxAlign(unsigned Align) { LocalFrameMaxAlign = Align; } + + /// Return the required alignment of the local object blob. + unsigned getLocalFrameMaxAlign() const { return LocalFrameMaxAlign; } + + /// Get whether the local allocation blob should be allocated together or + /// let PEI allocate the locals in it directly. + bool getUseLocalStackAllocationBlock() const { + return UseLocalStackAllocationBlock; + } + + /// setUseLocalStackAllocationBlock - Set whether the local allocation blob + /// should be allocated together or let PEI allocate the locals in it + /// directly. + void setUseLocalStackAllocationBlock(bool v) { + UseLocalStackAllocationBlock = v; + } + + /// Return true if the object was pre-allocated into the local block. + bool isObjectPreAllocated(int ObjectIdx) const { + assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && + "Invalid Object Idx!"); + return Objects[ObjectIdx+NumFixedObjects].PreAllocated; + } + + /// Return the size of the specified object. + int64_t getObjectSize(int ObjectIdx) const { + assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && + "Invalid Object Idx!"); + return Objects[ObjectIdx+NumFixedObjects].Size; + } + + /// Change the size of the specified stack object. + void setObjectSize(int ObjectIdx, int64_t Size) { + assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && + "Invalid Object Idx!"); + Objects[ObjectIdx+NumFixedObjects].Size = Size; + } + + /// Return the alignment of the specified stack object. + unsigned getObjectAlignment(int ObjectIdx) const { + assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && + "Invalid Object Idx!"); + return Objects[ObjectIdx+NumFixedObjects].Alignment; + } + + /// setObjectAlignment - Change the alignment of the specified stack object. + void setObjectAlignment(int ObjectIdx, unsigned Align) { + assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && + "Invalid Object Idx!"); + Objects[ObjectIdx+NumFixedObjects].Alignment = Align; + ensureMaxAlignment(Align); + } + + /// Return the underlying Alloca of the specified + /// stack object if it exists. Returns 0 if none exists. + const AllocaInst* getObjectAllocation(int ObjectIdx) const { + assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && + "Invalid Object Idx!"); + return Objects[ObjectIdx+NumFixedObjects].Alloca; + } + + /// Return the assigned stack offset of the specified object + /// from the incoming stack pointer. + int64_t getObjectOffset(int ObjectIdx) const { + assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && + "Invalid Object Idx!"); + assert(!isDeadObjectIndex(ObjectIdx) && + "Getting frame offset for a dead object?"); + return Objects[ObjectIdx+NumFixedObjects].SPOffset; + } + + bool isObjectZExt(int ObjectIdx) const { + assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && + "Invalid Object Idx!"); + return Objects[ObjectIdx+NumFixedObjects].isZExt; + } + + void setObjectZExt(int ObjectIdx, bool IsZExt) { + assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && + "Invalid Object Idx!"); + Objects[ObjectIdx+NumFixedObjects].isZExt = IsZExt; + } + + bool isObjectSExt(int ObjectIdx) const { + assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && + "Invalid Object Idx!"); + return Objects[ObjectIdx+NumFixedObjects].isSExt; + } + + void setObjectSExt(int ObjectIdx, bool IsSExt) { + assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && + "Invalid Object Idx!"); + Objects[ObjectIdx+NumFixedObjects].isSExt = IsSExt; + } + + /// Set the stack frame offset of the specified object. The + /// offset is relative to the stack pointer on entry to the function. + void setObjectOffset(int ObjectIdx, int64_t SPOffset) { + assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && + "Invalid Object Idx!"); + assert(!isDeadObjectIndex(ObjectIdx) && + "Setting frame offset for a dead object?"); + Objects[ObjectIdx+NumFixedObjects].SPOffset = SPOffset; + } + + SSPLayoutKind getObjectSSPLayout(int ObjectIdx) const { + assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && + "Invalid Object Idx!"); + return (SSPLayoutKind)Objects[ObjectIdx+NumFixedObjects].SSPLayout; + } + + void setObjectSSPLayout(int ObjectIdx, SSPLayoutKind Kind) { + assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && + "Invalid Object Idx!"); + assert(!isDeadObjectIndex(ObjectIdx) && + "Setting SSP layout for a dead object?"); + Objects[ObjectIdx+NumFixedObjects].SSPLayout = Kind; + } + + /// Return the number of bytes that must be allocated to hold + /// all of the fixed size frame objects. This is only valid after + /// Prolog/Epilog code insertion has finalized the stack frame layout. + uint64_t getStackSize() const { return StackSize; } + + /// Set the size of the stack. + void setStackSize(uint64_t Size) { StackSize = Size; } + + /// Estimate and return the size of the stack frame. + unsigned estimateStackSize(const MachineFunction &MF) const; + + /// Return the correction for frame offsets. + int getOffsetAdjustment() const { return OffsetAdjustment; } + + /// Set the correction for frame offsets. + void setOffsetAdjustment(int Adj) { OffsetAdjustment = Adj; } + + /// Return the alignment in bytes that this function must be aligned to, + /// which is greater than the default stack alignment provided by the target. + unsigned getMaxAlignment() const { return MaxAlignment; } + + /// Make sure the function is at least Align bytes aligned. + void ensureMaxAlignment(unsigned Align); + + /// Return true if this function adjusts the stack -- e.g., + /// when calling another function. This is only valid during and after + /// prolog/epilog code insertion. + bool adjustsStack() const { return AdjustsStack; } + void setAdjustsStack(bool V) { AdjustsStack = V; } + + /// Return true if the current function has any function calls. + bool hasCalls() const { return HasCalls; } + void setHasCalls(bool V) { HasCalls = V; } + + /// Returns true if the function contains opaque dynamic stack adjustments. + bool hasOpaqueSPAdjustment() const { return HasOpaqueSPAdjustment; } + void setHasOpaqueSPAdjustment(bool B) { HasOpaqueSPAdjustment = B; } + + /// Returns true if the function contains operations which will lower down to + /// instructions which manipulate the stack pointer. + bool hasCopyImplyingStackAdjustment() const { + return HasCopyImplyingStackAdjustment; + } + void setHasCopyImplyingStackAdjustment(bool B) { + HasCopyImplyingStackAdjustment = B; + } + + /// Returns true if the function calls the llvm.va_start intrinsic. + bool hasVAStart() const { return HasVAStart; } + void setHasVAStart(bool B) { HasVAStart = B; } + + /// Returns true if the function is variadic and contains a musttail call. + bool hasMustTailInVarArgFunc() const { return HasMustTailInVarArgFunc; } + void setHasMustTailInVarArgFunc(bool B) { HasMustTailInVarArgFunc = B; } + + /// Returns true if the function contains a tail call. + bool hasTailCall() const { return HasTailCall; } + void setHasTailCall() { HasTailCall = true; } + + /// Computes the maximum size of a callframe and the AdjustsStack property. + /// This only works for targets defining + /// TargetInstrInfo::getCallFrameSetupOpcode(), getCallFrameDestroyOpcode(), + /// and getFrameSize(). + /// This is usually computed by the prologue epilogue inserter but some + /// targets may call this to compute it earlier. + void computeMaxCallFrameSize(const MachineFunction &MF); + + /// Return the maximum size of a call frame that must be + /// allocated for an outgoing function call. This is only available if + /// CallFrameSetup/Destroy pseudo instructions are used by the target, and + /// then only during or after prolog/epilog code insertion. + /// + unsigned getMaxCallFrameSize() const { + // TODO: Enable this assert when targets are fixed. + //assert(isMaxCallFrameSizeComputed() && "MaxCallFrameSize not computed yet"); + if (!isMaxCallFrameSizeComputed()) + return 0; + return MaxCallFrameSize; + } + bool isMaxCallFrameSizeComputed() const { + return MaxCallFrameSize != ~0u; + } + void setMaxCallFrameSize(unsigned S) { MaxCallFrameSize = S; } + + /// Returns how many bytes of callee-saved registers the target pushed in the + /// prologue. Only used for debug info. + unsigned getCVBytesOfCalleeSavedRegisters() const { + return CVBytesOfCalleeSavedRegisters; + } + void setCVBytesOfCalleeSavedRegisters(unsigned S) { + CVBytesOfCalleeSavedRegisters = S; + } + + /// Create a new object at a fixed location on the stack. + /// All fixed objects should be created before other objects are created for + /// efficiency. By default, fixed objects are not pointed to by LLVM IR + /// values. This returns an index with a negative value. + int CreateFixedObject(uint64_t Size, int64_t SPOffset, bool IsImmutable, + bool isAliased = false); + + /// Create a spill slot at a fixed location on the stack. + /// Returns an index with a negative value. + int CreateFixedSpillStackObject(uint64_t Size, int64_t SPOffset, + bool IsImmutable = false); + + /// Returns true if the specified index corresponds to a fixed stack object. + bool isFixedObjectIndex(int ObjectIdx) const { + return ObjectIdx < 0 && (ObjectIdx >= -(int)NumFixedObjects); + } + + /// Returns true if the specified index corresponds + /// to an object that might be pointed to by an LLVM IR value. + bool isAliasedObjectIndex(int ObjectIdx) const { + assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && + "Invalid Object Idx!"); + return Objects[ObjectIdx+NumFixedObjects].isAliased; + } + + /// Returns true if the specified index corresponds to an immutable object. + bool isImmutableObjectIndex(int ObjectIdx) const { + // Tail calling functions can clobber their function arguments. + if (HasTailCall) + return false; + assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && + "Invalid Object Idx!"); + return Objects[ObjectIdx+NumFixedObjects].isImmutable; + } + + /// Marks the immutability of an object. + void setIsImmutableObjectIndex(int ObjectIdx, bool IsImmutable) { + assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && + "Invalid Object Idx!"); + Objects[ObjectIdx+NumFixedObjects].isImmutable = IsImmutable; + } + + /// Returns true if the specified index corresponds to a spill slot. + bool isSpillSlotObjectIndex(int ObjectIdx) const { + assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && + "Invalid Object Idx!"); + return Objects[ObjectIdx+NumFixedObjects].isSpillSlot; + } + + bool isStatepointSpillSlotObjectIndex(int ObjectIdx) const { + assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && + "Invalid Object Idx!"); + return Objects[ObjectIdx+NumFixedObjects].isStatepointSpillSlot; + } + + /// \see StackID + uint8_t getStackID(int ObjectIdx) const { + return Objects[ObjectIdx+NumFixedObjects].StackID; + } + + /// \see StackID + void setStackID(int ObjectIdx, uint8_t ID) { + assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && + "Invalid Object Idx!"); + Objects[ObjectIdx+NumFixedObjects].StackID = ID; + } + + /// Returns true if the specified index corresponds to a dead object. + bool isDeadObjectIndex(int ObjectIdx) const { + assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && + "Invalid Object Idx!"); + return Objects[ObjectIdx+NumFixedObjects].Size == ~0ULL; + } + + /// Returns true if the specified index corresponds to a variable sized + /// object. + bool isVariableSizedObjectIndex(int ObjectIdx) const { + assert(unsigned(ObjectIdx + NumFixedObjects) < Objects.size() && + "Invalid Object Idx!"); + return Objects[ObjectIdx + NumFixedObjects].Size == 0; + } + + void markAsStatepointSpillSlotObjectIndex(int ObjectIdx) { + assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && + "Invalid Object Idx!"); + Objects[ObjectIdx+NumFixedObjects].isStatepointSpillSlot = true; + assert(isStatepointSpillSlotObjectIndex(ObjectIdx) && "inconsistent"); + } + + /// Create a new statically sized stack object, returning + /// a nonnegative identifier to represent it. + int CreateStackObject(uint64_t Size, unsigned Alignment, bool isSpillSlot, + const AllocaInst *Alloca = nullptr, uint8_t ID = 0); + + /// Create a new statically sized stack object that represents a spill slot, + /// returning a nonnegative identifier to represent it. + int CreateSpillStackObject(uint64_t Size, unsigned Alignment); + + /// Remove or mark dead a statically sized stack object. + void RemoveStackObject(int ObjectIdx) { + // Mark it dead. + Objects[ObjectIdx+NumFixedObjects].Size = ~0ULL; + } + + /// Notify the MachineFrameInfo object that a variable sized object has been + /// created. This must be created whenever a variable sized object is + /// created, whether or not the index returned is actually used. + int CreateVariableSizedObject(unsigned Alignment, const AllocaInst *Alloca); + + /// Returns a reference to call saved info vector for the current function. + const std::vector<CalleeSavedInfo> &getCalleeSavedInfo() const { + return CSInfo; + } + /// \copydoc getCalleeSavedInfo() + std::vector<CalleeSavedInfo> &getCalleeSavedInfo() { return CSInfo; } + + /// Used by prolog/epilog inserter to set the function's callee saved + /// information. + void setCalleeSavedInfo(const std::vector<CalleeSavedInfo> &CSI) { + CSInfo = CSI; + } + + /// Has the callee saved info been calculated yet? + bool isCalleeSavedInfoValid() const { return CSIValid; } + + void setCalleeSavedInfoValid(bool v) { CSIValid = v; } + + MachineBasicBlock *getSavePoint() const { return Save; } + void setSavePoint(MachineBasicBlock *NewSave) { Save = NewSave; } + MachineBasicBlock *getRestorePoint() const { return Restore; } + void setRestorePoint(MachineBasicBlock *NewRestore) { Restore = NewRestore; } + + /// Return a set of physical registers that are pristine. + /// + /// Pristine registers hold a value that is useless to the current function, + /// but that must be preserved - they are callee saved registers that are not + /// saved. + /// + /// Before the PrologueEpilogueInserter has placed the CSR spill code, this + /// method always returns an empty set. + BitVector getPristineRegs(const MachineFunction &MF) const; + + /// Used by the MachineFunction printer to print information about + /// stack objects. Implemented in MachineFunction.cpp. + void print(const MachineFunction &MF, raw_ostream &OS) const; + + /// dump - Print the function to stderr. + void dump(const MachineFunction &MF) const; +}; + +} // End llvm namespace + +#endif |