llvm-6502/include/llvm/ParameterAttributes.h
Reid Spencer 021220c8cd Chris convinced me that the default size of the SmallVector (2) was too
small.  Since it doesn't cost much to have 2 more (8 bytes), but not having
them would require a malloc as soon as the third one is needed. Setting
the default to 4 delays the malloc until the 5th parameter attribute.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35793 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-09 01:53:54 +00:00

166 lines
7.2 KiB
C++

//===-- llvm/ParameterAttributes.h - Container for Param Attrs --*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Reid Spencer and is distributed under the
// University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the types necessary to represent the parameter attributes
// associated with functions and their calls.
//
// The implementations of these classes live in lib/VMCore/Function.cpp.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_PARAMETER_ATTRIBUTES_H
#define LLVM_PARAMETER_ATTRIBUTES_H
#include "llvm/ADT/SmallVector.h"
namespace llvm {
/// Function parameters 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.
enum ParameterAttributes {
NoAttributeSet = 0, ///< No attributes have been set
ZExtAttribute = 1 << 0, ///< zero extended before/after call
SExtAttribute = 1 << 1, ///< sign extended before/after call
NoReturnAttribute = 1 << 2, ///< mark the function as not returning
InRegAttribute = 1 << 3, ///< force argument to be passed in register
StructRetAttribute = 1 << 4, ///< hidden pointer to structure to return
NoUnwindAttribute = 1 << 5 ///< Function doesn't unwind stack
};
/// This class is used by Function and CallInst to represent the set of
/// parameter attributes used. It represents a list of pairs of uint16_t, one
/// for the parameter index, and one a set of ParameterAttributes bits.
/// Parameters that have no attributes are not present in the list. The list
/// may also be empty, but this doesn't occur in practice. The list constructs
/// as empty and is filled by the insert method. The list can be turned into
/// a string of mnemonics suitable for LLVM Assembly output. Various accessors
/// are provided to obtain information about the attributes.
/// @brief A List of ParameterAttributes.
class ParamAttrsList {
/// @name Accessors
/// @{
public:
/// The parameter attributes for the \p indexth parameter are returned.
/// The 0th parameter refers to the return type of the function. Note that
/// the \p param_index is an index into the function's parameters, not an
/// index into this class's list of attributes. The result of getParamIndex
/// is always suitable input to this function.
/// @returns The all the ParameterAttributes for the \p indexth parameter
/// as a uint16_t of enumeration values OR'd together.
/// @brief Get the attributes for a parameter
uint16_t getParamAttrs(uint16_t param_index) const;
/// This checks to see if the \p ith function parameter has the parameter
/// attribute given by \p attr set.
/// @returns true if the parameter attribute is set
/// @brief Determine if a ParameterAttributes is set
bool paramHasAttr(uint16_t i, ParameterAttributes attr) const {
return getParamAttrs(i) & attr;
}
/// The set of ParameterAttributes 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
static std::string getParamAttrsText(uint16_t Attributes);
/// The \p Indexth parameter attribute is converted to string.
/// @brief Get the text for the parmeter attributes for one parameter.
std::string getParamAttrsTextByIndex(uint16_t Index) const {
return getParamAttrsText(getParamAttrs(Index));
}
/// @brief Comparison operator for ParamAttrsList
bool operator < (const ParamAttrsList& that) const {
if (this->attrs.size() < that.attrs.size())
return true;
if (this->attrs.size() > that.attrs.size())
return false;
for (unsigned i = 0; i < attrs.size(); ++i) {
if (attrs[i].index < that.attrs[i].index)
return true;
if (attrs[i].index > that.attrs[i].index)
return false;
if (attrs[i].attrs < that.attrs[i].attrs)
return true;
if (attrs[i].attrs > that.attrs[i].attrs)
return false;
}
return false;
}
/// Returns the parameter index of a particular parameter attribute in this
/// list of attributes. Note that the attr_index is an index into this
/// class's list of attributes, not the index of a parameter. The result
/// is the index of the parameter. Clients generally should not use this
/// method. It is used internally by LLVM.
/// @brief Get a parameter index
uint16_t getParamIndex(unsigned attr_index) const {
return attrs[attr_index].index;
}
/// Determines how many parameter attributes are set in this ParamAttrsList.
/// This says nothing about how many parameters the function has. It also
/// says nothing about the highest parameter index that has attributes.
/// Clients generally should not use this method. It is used internally by
/// LLVM.
/// @returns the number of parameter attributes in this ParamAttrsList.
/// @brief Return the number of parameter attributes this type has.
unsigned size() const { return attrs.size(); }
/// Clients generally should not use this method. It is used internally by
/// LLVM.
/// @returns true if this ParamAttrsList is empty.
/// @brief Determine emptiness of ParamAttrsList.
unsigned empty() const { return attrs.empty(); }
/// @}
/// @name Mutators
/// @{
public:
/// This method will add the \p attrs to the parameter with index
/// \p param_index. If the parameter index does not exist it will be created
/// and the \p attrs will be the only attributes set. Otherwise, any
/// existing attributes for the specified parameter remain set and the
/// attributes given by \p attrs are also set.
/// @brief Add ParameterAttributes.
void addAttributes(uint16_t param_index, uint16_t attrs);
/// This method will remove the \p attrs to the parameter with index
/// \p param_index. If the parameter index does not exist in the list,
/// an assertion will occur. If the specified attributes are the last
/// attributes set for the specified parameter index, the attributes for
/// that index are removed completely from the list (size is decremented).
/// Otherwise, the specified attributes are removed from the set of
/// attributes for the given index, retaining any others.
/// @brief Remove a single ParameterAttribute
void removeAttributes(uint16_t param_index, uint16_t attrs);
/// @}
/// @name Data
/// @{
private:
/// This is an internal structure used to associate the ParameterAttributes
/// with a parameter index.
/// @brief ParameterAttributes with a parameter index.
struct ParamAttrsWithIndex {
uint16_t attrs; ///< The attributes that are set, |'d together
uint16_t index; ///< Index of the parameter for which the attributes apply
};
SmallVector<ParamAttrsWithIndex,4> attrs; ///< The list of attributes
/// @}
};
} // End llvm namespace
#endif