Struct ConstValueRef

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pub struct ConstValueRef(/* private fields */);

Implementations§

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impl ConstValueRef

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pub fn const_null(ty: &TypeRef) -> Self

Obtain a constant value referring to the null instance of a type.

§Details

Creates a constant ‘null’ value of the specified type.

This function wraps the LLVMConstNull function from the LLVM core library. It generates a constant ‘null’ value for the specified type (ty). This is typically used for pointer types, where the null value represents a pointer to no valid memory location, but it can also be used for other types where a zero-initialized constant is required.

§Parameters

ty: A reference to the type (TypeRef) for which the null value should be created. This type determines the kind of null value that is generated (e.g., null pointer, zero-initialized struct).

§Returns

Returns an instance of ValueRef, which encapsulates the constant null value for the specified type.

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pub fn const_all_ones(ty: &TypeRef) -> Self

Obtain a constant value referring to the instance of a type consisting of all ones.

This is only valid for integer types.

§Details

Creates a constant value with all bits set to one for the specified type.

This function wraps the LLVMConstAllOnes function from the LLVM core library. It generates a constant value for the specified type (ty) where all the bits are set to one. This is often used to represent a value where all bits are enabled, such as -1 for signed integers or the maximum possible value for unsigned integers.

§Parameters

ty: A reference to the type (TypeRef) for which the all-ones value should be created. This type determines the size and nature of the value (e.g., integer, vector).

§Returns

Returns an instance of ValueRef, which encapsulates the constant all-ones value for the specified type.

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pub fn get_undef(ty: &TypeRef) -> Self

Obtain a constant value referring to an undefined value of a type.

§Details

Creates an ‘undefined’ value of the specified type.

This function wraps the LLVMGetUndef function from the LLVM core library. It generates a constant ‘undefined’ value for the specified type (ty). An undefined value is a placeholder that can take any value of the specified type during program execution, typically used in optimization phases or when a value does not need to be initialized.

§Parameters

ty: A reference to the type (TypeRef) for which the undefined value should be created. This type determines the nature of the undefined value (e.g., integer, floating-point, vector).

§Returns

Returns an instance of ValueRef, which encapsulates the constant undefined value for the specified type.

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pub fn get_poison(ty: &TypeRef) -> Self

Obtain a constant value referring to a poison value of a type.

§Details

Creates a ‘poison’ value of the specified type.

This function wraps the LLVMGetPoison function from the LLVM core library. It generates a constant ‘poison’ value for the specified type (ty). A poison value is similar to an undefined value but more strict; it is used to represent a value that results from an operation with undefined behavior. Using a poison value in further operations can propagate the poison, potentially leading to further undefined behavior.

§Parameters

ty: A reference to the type (TypeRef) for which the poison value should be created. This type determines the nature of the poison value (e.g., integer, floating-point, vector).

§Returns

Returns an instance of ValueRef, which encapsulates the constant poison value for the specified type.

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pub fn is_null(&self) -> bool

Determine whether a value instance is null.

§Details

Checks if the value is a constant ‘null’ value.

This function wraps the LLVMIsNull function from the LLVM core library. It determines whether the value represented by self is a constant ‘null’ value. This is typically used to check if a pointer or other nullable type is explicitly set to null within the LLVM IR.

§Returns

Returns true if the value is a constant null value, otherwise returns false.

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pub fn const_pointer_null(ty: &TypeRef) -> Self

Obtain a constant that is a constant pointer pointing to NULL for a specified type.

§Details

Creates a constant null pointer value of the specified pointer type.

This function wraps the LLVMConstPointerNull function from the LLVM core library. It generates a constant null pointer for the specified pointer type (ty). This is typically used to represent a pointer that does not point to any valid memory location within LLVM IR.