Divide_Instruction

class Divide_Instruction (concrete, logical)

Division. Depending on Its_Type, this might be an integer (also: char/enum), floating-point, fixed-point, C99 imaginary floating-point, or C99 complex floating-point operation. It could also be a vectorized operation of any of the above.

Integer divisions in C truncate towards zero: 5 / 3 is 1; and -5 / 3 is -1. For integer divisions, the behavior is undefined on division by zero or if computing MIN_INT / -1 (integer overflow).

Note that mixed types are possible for these operations with C99 imaginary types:

  • real / imaginary → imaginary

  • imaginary / real → imaginary

  • imaginary / imaginary → real

In the real / imaginary case, this instruction does more than just a floating point division: it also divides the units (1.0 / I is -I), therefore negating the underlying result value.

For C99 complex types, this instruction performs the whole complex / complex → complex division in a single step.

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