Package ghidra.pcode.emu.jit.analysis

Interface JitType

All Known Subinterfaces:

JitType.LeggedJitType<T,LT>, JitType.SimpleJitType<T,JT>

All Known Implementing Classes:

JitType.DoubleJitType, JitType.FloatJitType, JitType.IntJitType, JitType.LongJitType, JitType.MpFloatJitType, JitType.MpIntJitType

public interface JitType

The p-code type of an operand.

A type is an integer of floating-point value of a specific size in bytes. All values and variables in p-code are just bit vectors. The operators interpret those vectors according to a JitTypeBehavior. While types only technically belong to the operands, we also talk about values, variables, and varnodes being assigned types, so that we can allocate suitable JVM locals.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static enum	JitType.DoubleJitType	The p-code type for floating-point of size 8, i.e., that fits in a JVM double.
static enum	JitType.FloatJitType	The p-code type for floating-point of size 4, i.e., that fits in a JVM float.
static final record	JitType.IntJitType	The p-code types for integers of size 1 through 4, i.e., that fit in a JVM int.
static interface	JitType.LeggedJitType<T extends Types.BPrim<?>,LT extends JitType.SimpleJitType<T,LT>>	A type comprising of legs, each of simple type
static final record	JitType.LongJitType	The p-code types for integers of size 5 through 8, i.e., that fit in a JVM long.
static final record	JitType.MpFloatJitType	WIP: The p-code types for floats of size other than 4 and 8
static final record	JitType.MpIntJitType	The p-code types for integers of size 9 and greater.
static interface	JitType.SimpleJitType<T extends Types.BPrim<?>,JT extends JitType.SimpleJitType<T,JT>>	A p-code type that can be represented in a single JVM variable.

Method Summary

Modifier and Type	Method	Description
static int	compare(JitType t1, JitType t2)	Compare two types by preference.
JitType	ext()	Extend this p-code type to the p-code type that fills its entire host JVM type.
static JitType	forJavaType(Class<?> cls)	Identify the p-code type that is exactly represented by the given JVM type.
List<? extends JitType.SimpleJitType<?,?>>	legTypesBE()	Get the p-code type that describes the part of the variable in each leg
List<? extends JitType.SimpleJitType<?,?>>	legTypesLE()	Get the p-code type that describes the part of the variable in each leg
String	nm()	Part of the name of a JVM local variable allocated for this type
int	pref()	The preference for this type.
int	size()	The size of this type
static JitType	unify(JitType a, JitType b)	Get the smallest type to which both of the given types can be converted without loss.
static JitType	unifyLeast(JitType a, JitType b)	Similar to unify(JitType, JitType), except that it takes the lesser size.

Method Details

unify

static JitType unify(JitType a,
 JitType b)

Get the smallest type to which both of the given types can be converted without loss.

When the given types are a mix of integral and floating-point, this chooses an integral type whose size is the greater of the two.

Parameters:

a - the first type

b - the second type

Returns:

the uniform type

unifyLeast

static JitType unifyLeast(JitType a,
 JitType b)

Similar to unify(JitType, JitType), except that it takes the lesser size.

This is used when culling of unnecessary loads is desired and loss of precision is acceptable.

Parameters:

a - the first type

b - the second type

Returns:

the uniform type

compare

static int compare(JitType t1,
 JitType t2)

Compare two types by preference. The type with the more preferred behavior then smaller size is preferred.

Parameters:

t1 - the first type

t2 - the second type

Returns:

as in Comparator.compare(Object, Object)

forJavaType

static JitType forJavaType(Class<?> cls)

Identify the p-code type that is exactly represented by the given JVM type.

This is used during Direct userop invocation to convert the arguments and return value.

Parameters:

cls - the primitive class (not boxed)

Returns:

the p-code type

See Also:

• JitDataFlowUseropLibrary

pref

int pref()

The preference for this type. Smaller is more preferred.

Returns:

the preference

nm

String nm()

Part of the name of a JVM local variable allocated for this type

Returns:

the "type" part of a JVM local's name

size

int size()

The size of this type

Returns:

the size in bytes

ext

JitType ext()

Extend this p-code type to the p-code type that fills its entire host JVM type.

This is useful, e.g., when multiplying two int3 values using imul that the result might be an int4 and so may need additional conversion.

Returns:

the extended type

legTypesBE

List<? extends JitType.SimpleJitType<?,?>> legTypesBE()

Get the p-code type that describes the part of the variable in each leg

Each whole leg will have the type JitType.IntJitType.I4, and the partial leg, if applicable, will have its appropriate smaller integer type.

Returns:

the list of types, each fitting in a JVM int, in big-endian order.

legTypesLE

List<? extends JitType.SimpleJitType<?,?>> legTypesLE()

Get the p-code type that describes the part of the variable in each leg

Each whole leg will have the type JitType.IntJitType.I4, and the partial leg, if applicable, will have its appropriate smaller integer type.

Returns:

the list of types, each fitting in a JVM int, in little-endian order.