-//===-- llvm/Attributes.h - Container for ParamAttrs ---*---------- C++ -*-===//
+//===-- llvm/Attributes.h - Container for Attributes ------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
//
//===----------------------------------------------------------------------===//
//
-// This file contains the simple types necessary to represent the parameter
+// This file contains the simple types necessary to represent the
// attributes associated with functions and their calls.
//
//===----------------------------------------------------------------------===//
-#ifndef LLVM_PARAMETER_ATTRIBUTES_H
-#define LLVM_PARAMETER_ATTRIBUTES_H
+#ifndef LLVM_ATTRIBUTES_H
+#define LLVM_ATTRIBUTES_H
+#include "llvm/Support/MathExtras.h"
+#include "llvm/ADT/ArrayRef.h"
+#include <cassert>
#include <string>
namespace llvm {
+
+class LLVMContext;
class Type;
-/// Attributes - A bitset of attributes for a parameter.
-typedef unsigned Attributes;
-
-namespace ParamAttr {
-
-/// Function parameters and results can have attributes to indicate how they
-/// should be treated by optimizations and code generation. This enumeration
-/// lists the attributes that can be associated with parameters or function
-/// results.
-/// @brief Function parameter attributes.
-
-const Attributes None = 0; ///< No attributes have been set
-const Attributes ZExt = 1<<0; ///< Zero extended before/after call
-const Attributes SExt = 1<<1; ///< Sign extended before/after call
-const Attributes NoReturn = 1<<2; ///< Mark the function as not returning
-const Attributes InReg = 1<<3; ///< Force argument to be passed in register
-const Attributes StructRet = 1<<4; ///< Hidden pointer to structure to return
-const Attributes NoUnwind = 1<<5; ///< Function doesn't unwind stack
-const Attributes NoAlias = 1<<6; ///< Considered to not alias after call
-const Attributes ByVal = 1<<7; ///< Pass structure by value
-const Attributes Nest = 1<<8; ///< Nested function static chain
-const Attributes ReadNone = 1<<9; ///< Function does not access memory
-const Attributes ReadOnly = 1<<10; ///< Function only reads from memory
-const Attributes Alignment = 0xffff<<16; ///< Alignment of parameter (16 bits)
- // 0 = unknown, else in clear (not log)
-
-/// @brief Attributes that only apply to function parameters.
-const Attributes ParameterOnly = ByVal | Nest | StructRet;
-
-/// @brief Attributes that only apply to function return values.
-const Attributes ReturnOnly = NoReturn | NoUnwind | ReadNone | ReadOnly;
-
-/// @brief Parameter attributes that do not apply to vararg call arguments.
-const Attributes VarArgsIncompatible = StructRet;
-
-/// @brief Attributes that are mutually incompatible.
-const Attributes MutuallyIncompatible[3] = {
- ByVal | InReg | Nest | StructRet,
- ZExt | SExt,
- ReadNone | ReadOnly
+/// AttributeImpl - The internal representation of the Attributes class. This is
+/// uniquified.
+class AttributesImpl;
+
+/// Attributes - A bitset of attributes.
+class Attributes {
+public:
+ /// Function parameters and results can have attributes to indicate how they
+ /// should be treated by optimizations and code generation. This enumeration
+ /// lists the attributes that can be associated with parameters, function
+ /// results or the function itself.
+ ///
+ /// Note that uwtable is about the ABI or the user mandating an entry in the
+ /// unwind table. The nounwind attribute is about an exception passing by the
+ /// function.
+ ///
+ /// In a theoretical system that uses tables for profiling and sjlj for
+ /// exceptions, they would be fully independent. In a normal system that uses
+ /// tables for both, the semantics are:
+ ///
+ /// nil = Needs an entry because an exception might pass by.
+ /// nounwind = No need for an entry
+ /// uwtable = Needs an entry because the ABI says so and because
+ /// an exception might pass by.
+ /// uwtable + nounwind = Needs an entry because the ABI says so.
+
+ enum AttrVal {
+ // IR-Level Attributes
+ None = 0, ///< No attributes have been set
+ AddressSafety = 1, ///< Address safety checking is on.
+ Alignment = 2, ///< Alignment of parameter (5 bits)
+ ///< stored as log2 of alignment with +1 bias
+ ///< 0 means unaligned different from align 1
+ AlwaysInline = 3, ///< inline=always
+ ByVal = 4, ///< Pass structure by value
+ InlineHint = 5, ///< Source said inlining was desirable
+ InReg = 6, ///< Force argument to be passed in register
+ Naked = 7, ///< Naked function
+ Nest = 8, ///< Nested function static chain
+ NoAlias = 9, ///< Considered to not alias after call
+ NoCapture = 10, ///< Function creates no aliases of pointer
+ NoImplicitFloat = 11, ///< Disable implicit floating point insts
+ NoInline = 12, ///< inline=never
+ NonLazyBind = 13, ///< Function is called early and/or
+ ///< often, so lazy binding isn't worthwhile
+ NoRedZone = 14, ///< Disable redzone
+ NoReturn = 15, ///< Mark the function as not returning
+ NoUnwind = 16, ///< Function doesn't unwind stack
+ OptimizeForSize = 17, ///< opt_size
+ ReadNone = 18, ///< Function does not access memory
+ ReadOnly = 19, ///< Function only reads from memory
+ ReturnsTwice = 20, ///< Function can return twice
+ SExt = 21, ///< Sign extended before/after call
+ StackAlignment = 22, ///< Alignment of stack for function (3 bits)
+ ///< stored as log2 of alignment with +1 bias 0
+ ///< means unaligned (different from
+ ///< alignstack={1))
+ StackProtect = 23, ///< Stack protection.
+ StackProtectReq = 24, ///< Stack protection required.
+ StructRet = 25, ///< Hidden pointer to structure to return
+ UWTable = 26, ///< Function must be in a unwind table
+ ZExt = 27 ///< Zero extended before/after call
+ };
+private:
+ AttributesImpl *Attrs;
+ Attributes(AttributesImpl *A);
+public:
+ Attributes() : Attrs(0) {}
+ Attributes(const Attributes &A);
+ Attributes &operator=(const Attributes &A) {
+ Attrs = A.Attrs;
+ return *this;
+ }
+
+ /// get - Return a uniquified Attributes object. This takes the uniquified
+ /// value from the Builder and wraps it in the Attributes class.
+ class Builder;
+ static Attributes get(LLVMContext &Context, ArrayRef<AttrVal> Vals);
+ static Attributes get(LLVMContext &Context, Builder &B);
+
+ //===--------------------------------------------------------------------===//
+ /// Attributes::Builder - This class is used in conjunction with the
+ /// Attributes::get method to create an Attributes object. The object itself
+ /// is uniquified. The Builder's value, however, is not. So this can be used
+ /// as a quick way to test for equality, presence of attributes, etc.
+ class Builder {
+ friend class Attributes;
+ uint64_t Bits;
+ public:
+ Builder() : Bits(0) {}
+ explicit Builder(uint64_t B) : Bits(B) {}
+ Builder(const Attributes &A) : Bits(A.Raw()) {}
+ Builder(const Builder &B) : Bits(B.Bits) {}
+
+ void clear() { Bits = 0; }
+
+ /// addAttribute - Add an attribute to the builder.
+ Builder &addAttribute(Attributes::AttrVal Val);
+
+ /// removeAttribute - Remove an attribute from the builder.
+ Builder &removeAttribute(Attributes::AttrVal Val);
+
+ /// addAttribute - Add the attributes from A to the builder.
+ Builder &addAttributes(const Attributes &A);
+
+ /// removeAttribute - Remove the attributes from A from the builder.
+ Builder &removeAttributes(const Attributes &A);
+
+ /// hasAttribute - Return true if the builder has the specified attribute.
+ bool hasAttribute(Attributes::AttrVal A) const;
+
+ /// hasAttributes - Return true if the builder has IR-level attributes.
+ bool hasAttributes() const;
+
+ /// hasAttributes - Return true if the builder has any attribute that's in
+ /// the specified attribute.
+ bool hasAttributes(const Attributes &A) const;
+
+ /// hasAlignmentAttr - Return true if the builder has an alignment
+ /// attribute.
+ bool hasAlignmentAttr() const;
+
+ /// getAlignment - Retrieve the alignment attribute, if it exists.
+ uint64_t getAlignment() const;
+
+ /// getStackAlignment - Retrieve the stack alignment attribute, if it
+ /// exists.
+ uint64_t getStackAlignment() const;
+
+ /// addAlignmentAttr - This turns an int alignment (which must be a power of
+ /// 2) into the form used internally in Attributes.
+ Builder &addAlignmentAttr(unsigned Align);
+
+ /// addStackAlignmentAttr - This turns an int stack alignment (which must be
+ /// a power of 2) into the form used internally in Attributes.
+ Builder &addStackAlignmentAttr(unsigned Align);
+
+ /// addRawValue - Add the raw value to the internal representation.
+ /// N.B. This should be used ONLY for decoding LLVM bitcode!
+ Builder &addRawValue(uint64_t Val);
+
+ /// @brief Remove attributes that are used on functions only.
+ void removeFunctionOnlyAttrs() {
+ removeAttribute(Attributes::NoReturn)
+ .removeAttribute(Attributes::NoUnwind)
+ .removeAttribute(Attributes::ReadNone)
+ .removeAttribute(Attributes::ReadOnly)
+ .removeAttribute(Attributes::NoInline)
+ .removeAttribute(Attributes::AlwaysInline)
+ .removeAttribute(Attributes::OptimizeForSize)
+ .removeAttribute(Attributes::StackProtect)
+ .removeAttribute(Attributes::StackProtectReq)
+ .removeAttribute(Attributes::NoRedZone)
+ .removeAttribute(Attributes::NoImplicitFloat)
+ .removeAttribute(Attributes::Naked)
+ .removeAttribute(Attributes::InlineHint)
+ .removeAttribute(Attributes::StackAlignment)
+ .removeAttribute(Attributes::UWTable)
+ .removeAttribute(Attributes::NonLazyBind)
+ .removeAttribute(Attributes::ReturnsTwice)
+ .removeAttribute(Attributes::AddressSafety);
+ }
+
+ bool operator==(const Builder &B) {
+ return Bits == B.Bits;
+ }
+ bool operator!=(const Builder &B) {
+ return Bits != B.Bits;
+ }
+ };
+
+ /// @brief Return true if the attribute is present.
+ bool hasAttribute(AttrVal Val) const;
+
+ /// @brief Return true if attributes exist
+ bool hasAttributes() const;
+
+ /// @brief Return true if the attributes are a non-null intersection.
+ bool hasAttributes(const Attributes &A) const;
+
+ /// @brief Returns the alignment field of an attribute as a byte alignment
+ /// value.
+ unsigned getAlignment() const;
+
+ /// @brief Returns the stack alignment field of an attribute as a byte
+ /// alignment value.
+ unsigned getStackAlignment() const;
+
+ /// @brief Parameter attributes that do not apply to vararg call arguments.
+ bool hasIncompatibleWithVarArgsAttrs() const {
+ return hasAttribute(Attributes::StructRet);
+ }
+
+ /// @brief Attributes that only apply to function parameters.
+ bool hasParameterOnlyAttrs() const {
+ return hasAttribute(Attributes::ByVal) ||
+ hasAttribute(Attributes::Nest) ||
+ hasAttribute(Attributes::StructRet) ||
+ hasAttribute(Attributes::NoCapture);
+ }
+
+ /// @brief Attributes that may be applied to the function itself. These cannot
+ /// be used on return values or function parameters.
+ bool hasFunctionOnlyAttrs() const {
+ return hasAttribute(Attributes::NoReturn) ||
+ hasAttribute(Attributes::NoUnwind) ||
+ hasAttribute(Attributes::ReadNone) ||
+ hasAttribute(Attributes::ReadOnly) ||
+ hasAttribute(Attributes::NoInline) ||
+ hasAttribute(Attributes::AlwaysInline) ||
+ hasAttribute(Attributes::OptimizeForSize) ||
+ hasAttribute(Attributes::StackProtect) ||
+ hasAttribute(Attributes::StackProtectReq) ||
+ hasAttribute(Attributes::NoRedZone) ||
+ hasAttribute(Attributes::NoImplicitFloat) ||
+ hasAttribute(Attributes::Naked) ||
+ hasAttribute(Attributes::InlineHint) ||
+ hasAttribute(Attributes::StackAlignment) ||
+ hasAttribute(Attributes::UWTable) ||
+ hasAttribute(Attributes::NonLazyBind) ||
+ hasAttribute(Attributes::ReturnsTwice) ||
+ hasAttribute(Attributes::AddressSafety);
+ }
+
+ bool operator==(const Attributes &A) const {
+ return Attrs == A.Attrs;
+ }
+ bool operator!=(const Attributes &A) const {
+ return Attrs != A.Attrs;
+ }
+
+ uint64_t Raw() const;
+
+ /// @brief Which attributes cannot be applied to a type.
+ static Attributes typeIncompatible(Type *Ty);
+
+ /// encodeLLVMAttributesForBitcode - This returns an integer containing an
+ /// encoding of all the LLVM attributes found in the given attribute bitset.
+ /// Any change to this encoding is a breaking change to bitcode compatibility.
+ static uint64_t encodeLLVMAttributesForBitcode(Attributes Attrs) {
+ // FIXME: It doesn't make sense to store the alignment information as an
+ // expanded out value, we should store it as a log2 value. However, we
+ // can't just change that here without breaking bitcode compatibility. If
+ // this ever becomes a problem in practice, we should introduce new tag
+ // numbers in the bitcode file and have those tags use a more efficiently
+ // encoded alignment field.
+
+ // Store the alignment in the bitcode as a 16-bit raw value instead of a
+ // 5-bit log2 encoded value. Shift the bits above the alignment up by 11
+ // bits.
+ uint64_t EncodedAttrs = Attrs.Raw() & 0xffff;
+ if (Attrs.hasAttribute(Attributes::Alignment))
+ EncodedAttrs |= Attrs.getAlignment() << 16;
+ EncodedAttrs |= (Attrs.Raw() & (0xfffULL << 21)) << 11;
+ return EncodedAttrs;
+ }
+
+ /// decodeLLVMAttributesForBitcode - This returns an attribute bitset
+ /// containing the LLVM attributes that have been decoded from the given
+ /// integer. This function must stay in sync with
+ /// 'encodeLLVMAttributesForBitcode'.
+ static Attributes decodeLLVMAttributesForBitcode(LLVMContext &C,
+ uint64_t EncodedAttrs) {
+ // The alignment is stored as a 16-bit raw value from bits 31--16. We shift
+ // the bits above 31 down by 11 bits.
+ unsigned Alignment = (EncodedAttrs & (0xffffULL << 16)) >> 16;
+ assert((!Alignment || isPowerOf2_32(Alignment)) &&
+ "Alignment must be a power of two.");
+
+ Attributes::Builder B(EncodedAttrs & 0xffff);
+ if (Alignment)
+ B.addAlignmentAttr(Alignment);
+ B.addRawValue((EncodedAttrs & (0xfffULL << 32)) >> 11);
+ return Attributes::get(C, B);
+ }
+
+ /// getAsString - The set of Attributes set in Attributes is converted to a
+ /// string of equivalent mnemonics. This is, presumably, for writing out the
+ /// mnemonics for the assembly writer.
+ /// @brief Convert attribute bits to text
+ std::string getAsString() const;
};
-/// @brief Which attributes cannot be applied to a type.
-Attributes typeIncompatible(const Type *Ty);
-
-/// This turns an int alignment (a power of 2, normally) into the
-/// form used internally in Attributes.
-inline Attributes constructAlignmentFromInt(unsigned i) {
- return (i << 16);
-}
-
-/// The set of Attributes set in Attributes is converted to a
-/// string of equivalent mnemonics. This is, presumably, for writing out
-/// the mnemonics for the assembly writer.
-/// @brief Convert parameter attribute bits to text
-std::string getAsString(Attributes Attrs);
-} // end namespace ParamAttr
-
-/// Function notes are implemented as attributes stored at index ~0 in
-/// parameter attribute list.
-const Attributes FN_NOTE_None = 0;
-const Attributes FN_NOTE_NoInline = 1<<0; // inline=never
-const Attributes FN_NOTE_AlwaysInline = 1<<1; // inline=always
-const Attributes FN_NOTE_OptimizeForSize = 1<<2; // opt_size
-
-/// This is just a pair of values to associate a set of parameter attributes
-/// with a parameter index.
-struct ParamAttrsWithIndex {
- Attributes Attrs; ///< The attributes that are set, or'd together.
- unsigned Index; ///< Index of the parameter for which the attributes apply.
-
- static ParamAttrsWithIndex get(unsigned Idx, Attributes Attrs) {
- ParamAttrsWithIndex P;
+//===----------------------------------------------------------------------===//
+// AttributeWithIndex
+//===----------------------------------------------------------------------===//
+
+/// AttributeWithIndex - This is just a pair of values to associate a set of
+/// attributes with an index.
+struct AttributeWithIndex {
+ Attributes Attrs; ///< The attributes that are set, or'd together.
+ unsigned Index; ///< Index of the parameter for which the attributes apply.
+ ///< Index 0 is used for return value attributes.
+ ///< Index ~0U is used for function attributes.
+
+ static AttributeWithIndex get(LLVMContext &C, unsigned Idx,
+ ArrayRef<Attributes::AttrVal> Attrs) {
+ Attributes::Builder B;
+
+ for (ArrayRef<Attributes::AttrVal>::iterator I = Attrs.begin(),
+ E = Attrs.end(); I != E; ++I)
+ B.addAttribute(*I);
+
+ AttributeWithIndex P;
+ P.Index = Idx;
+ P.Attrs = Attributes::get(C, B);
+ return P;
+ }
+ static AttributeWithIndex get(unsigned Idx, Attributes Attrs) {
+ AttributeWithIndex P;
P.Index = Idx;
P.Attrs = Attrs;
return P;
}
};
-
+
//===----------------------------------------------------------------------===//
-// PAListPtr Smart Pointer
+// AttrListPtr Smart Pointer
//===----------------------------------------------------------------------===//
-class ParamAttributeListImpl;
-
-/// PAListPtr - This class manages the ref count for the opaque
-/// ParamAttributeListImpl object and provides accessors for it.
-class PAListPtr {
- /// PAList - The parameter attributes that we are managing. This can be null
- /// to represent the empty parameter attributes list.
- ParamAttributeListImpl *PAList;
+class AttributeListImpl;
+
+/// AttrListPtr - This class manages the ref count for the opaque
+/// AttributeListImpl object and provides accessors for it.
+class AttrListPtr {
public:
- PAListPtr() : PAList(0) {}
- PAListPtr(const PAListPtr &P);
- const PAListPtr &operator=(const PAListPtr &RHS);
- ~PAListPtr();
-
+ enum AttrIndex {
+ ReturnIndex = 0U,
+ FunctionIndex = ~0U
+ };
+private:
+ /// AttrList - The attributes that we are managing. This can be null
+ /// to represent the empty attributes list.
+ AttributeListImpl *AttrList;
+public:
+ AttrListPtr() : AttrList(0) {}
+ AttrListPtr(const AttrListPtr &P);
+ const AttrListPtr &operator=(const AttrListPtr &RHS);
+ ~AttrListPtr();
+
//===--------------------------------------------------------------------===//
- // Parameter Attribute List Construction and Mutation
+ // Attribute List Construction and Mutation
//===--------------------------------------------------------------------===//
-
- /// get - Return a ParamAttrs list with the specified parameter in it.
- static PAListPtr get(const ParamAttrsWithIndex *Attr, unsigned NumAttrs);
-
- /// get - Return a ParamAttr list with the parameters specified by the
- /// consecutive random access iterator range.
- template <typename Iter>
- static PAListPtr get(const Iter &I, const Iter &E) {
- if (I == E) return PAListPtr(); // Empty list.
- return get(&*I, static_cast<unsigned>(E-I));
- }
+
+ /// get - Return a Attributes list with the specified parameters in it.
+ static AttrListPtr get(ArrayRef<AttributeWithIndex> Attrs);
/// addAttr - Add the specified attribute at the specified index to this
- /// attribute list. Since parameter attribute lists are immutable, this
+ /// attribute list. Since attribute lists are immutable, this
/// returns the new list.
- PAListPtr addAttr(unsigned Idx, Attributes Attrs) const;
-
+ AttrListPtr addAttr(LLVMContext &C, unsigned Idx, Attributes Attrs) const;
+
/// removeAttr - Remove the specified attribute at the specified index from
- /// this attribute list. Since parameter attribute lists are immutable, this
+ /// this attribute list. Since attribute lists are immutable, this
/// returns the new list.
- PAListPtr removeAttr(unsigned Idx, Attributes Attrs) const;
-
+ AttrListPtr removeAttr(LLVMContext &C, unsigned Idx, Attributes Attrs) const;
+
//===--------------------------------------------------------------------===//
- // Parameter Attribute List Accessors
+ // Attribute List Accessors
//===--------------------------------------------------------------------===//
-
- /// getParamAttrs - The parameter attributes for the specified parameter are
- /// returned. Parameters for the result are denoted with Idx = 0.
- Attributes getParamAttrs(unsigned Idx) const;
-
+ /// getParamAttributes - The attributes for the specified index are
+ /// returned.
+ Attributes getParamAttributes(unsigned Idx) const {
+ return getAttributes(Idx);
+ }
+
+ /// getRetAttributes - The attributes for the ret value are
+ /// returned.
+ Attributes getRetAttributes() const {
+ return getAttributes(ReturnIndex);
+ }
+
+ /// getFnAttributes - The function attributes are returned.
+ Attributes getFnAttributes() const {
+ return getAttributes(FunctionIndex);
+ }
+
/// paramHasAttr - Return true if the specified parameter index has the
/// specified attribute set.
bool paramHasAttr(unsigned Idx, Attributes Attr) const {
- return getParamAttrs(Idx) & Attr;
+ return getAttributes(Idx).hasAttributes(Attr);
}
-
+
/// getParamAlignment - Return the alignment for the specified function
/// parameter.
unsigned getParamAlignment(unsigned Idx) const {
- return (getParamAttrs(Idx) & ParamAttr::Alignment) >> 16;
+ return getAttributes(Idx).getAlignment();
}
-
+
/// hasAttrSomewhere - Return true if the specified attribute is set for at
/// least one parameter or for the return value.
- bool hasAttrSomewhere(Attributes Attr) const;
+ bool hasAttrSomewhere(Attributes::AttrVal Attr) const;
+
+ unsigned getNumAttrs() const;
+ Attributes &getAttributesAtIndex(unsigned i) const;
/// operator==/!= - Provide equality predicates.
- bool operator==(const PAListPtr &RHS) const { return PAList == RHS.PAList; }
- bool operator!=(const PAListPtr &RHS) const { return PAList != RHS.PAList; }
-
+ bool operator==(const AttrListPtr &RHS) const
+ { return AttrList == RHS.AttrList; }
+ bool operator!=(const AttrListPtr &RHS) const
+ { return AttrList != RHS.AttrList; }
+
void dump() const;
//===--------------------------------------------------------------------===//
- // Parameter Attribute List Introspection
+ // Attribute List Introspection
//===--------------------------------------------------------------------===//
-
+
/// getRawPointer - Return a raw pointer that uniquely identifies this
- /// parameter attribute list.
+ /// attribute list.
void *getRawPointer() const {
- return PAList;
+ return AttrList;
}
-
- // Parameter attributes are stored as a dense set of slots, where there is one
+
+ // Attributes are stored as a dense set of slots, where there is one
// slot for each argument that has an attribute. This allows walking over the
// dense set instead of walking the sparse list of attributes.
-
- /// isEmpty - Return true if no parameters have an attribute.
+
+ /// isEmpty - Return true if there are no attributes.
///
bool isEmpty() const {
- return PAList == 0;
+ return AttrList == 0;
}
-
- /// getNumSlots - Return the number of slots used in this attribute list.
+
+ /// getNumSlots - Return the number of slots used in this attribute list.
/// This is the number of arguments that have an attribute set on them
/// (including the function itself).
unsigned getNumSlots() const;
-
- /// getSlot - Return the ParamAttrsWithIndex at the specified slot. This
- /// holds a parameter number plus a set of attributes.
- const ParamAttrsWithIndex &getSlot(unsigned Slot) const;
-
+
+ /// getSlot - Return the AttributeWithIndex at the specified slot. This
+ /// holds a index number plus a set of attributes.
+ const AttributeWithIndex &getSlot(unsigned Slot) const;
+
private:
- explicit PAListPtr(ParamAttributeListImpl *L);
+ explicit AttrListPtr(AttributeListImpl *L);
+
+ /// getAttributes - The attributes for the specified index are
+ /// returned. Attributes for the result are denoted with Idx = 0.
+ Attributes getAttributes(unsigned Idx) const;
};
} // End llvm namespace
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