Modulo_Instruction

class Modulo_Instruction (concrete, logical)

The remainder operator (%). Its_Type will be an integer type (also: char/enum); or a vector of integer types.

Because integer divisions in C truncate towards zero, the remainder can also be negative: 5 % 3 is 2; and -5 % 3 is -2. Calling this operation “modulo” is only accurate for unsigned integer types.

This operation has undefined behavior on division by zero; and also for MIN_INT % -1`, even though it's only the division that's overflowing. This is because the C standard defines that ``a % b has UB iff a / b has UB.

Direct parents:
Ancestor classes and implemented interfaces:

Arithmetic_Instruction, Binary_Instruction, Execution_Node, Instruction, Logical_IR_Root

Field

Kind

Type

Description

First (from Binary_Instruction)

syntactic

interface Reading_Or_Address_Operand_Interface

First input operand of the binary instruction.

Second (from Binary_Instruction)

syntactic

interface Reading_Or_Address_Operand_Interface

Second input operand of the binary instruction.

Left (from Instruction)

syntactic

class Operand

Where the result will be stored. This is always a write operand. (can be NULL, e.g., for calls to void funcs or assertion instructions. Check cafe’s can_omit_lhs() for the full list of instructions that can have Left equal to NoNode.)

Left_Physical (from Instruction)

semantic to physical

class Physical_IR_Root

This edge instead points to the expression that represents the left operand, i.e., the expression that computed the glvalue where the result of the instruction will be stored.

For example, in v = 42; (a LIR Integer_Literal_Instruction):

Its_Type (from Instruction)

semantic

class Type

Result type of the instruction, needed especially to distinguish assignments of complete structs from assignments of their first fields. Also needed to determine multiplication factor for pointer additions. For Cast_Instructions, this is the type casted to

Physical_For_Assignment (from Instruction)

semantic to physical

class Physical_IR_Root

Returns a PIR node for the assignment of the value that was computed by this instruction.

For example, in v = 42; (a LIR Integer_Literal_Instruction):

Parent (from Logical_IR_Root)

semantic

class Logical_IR_Root

Physical (from Logical_IR_Root)

semantic to physical

class Physical_IR_Root