MUL

Purpose

perform arithmetic multiplication

Format

opcode mulr.rx, prod.mx                                  2 operand

opcode mulr.rx, muld.rx, prod.wx                     3 operand

Operation

prod ß prod * mulr;                                        2 operand

prod ß muld * mulr;                                        3 operand

Condition codes

N ß prod LSS 0;

Z ß prod EQL 0;

V ß overflow;

C ß 0;

Exceptions

Integer overflow

Floating overflow

Floating underflow

Reserved operand

Opcodes

84        MULB2           Multiply Byte 2 Operand

85        MULB3           Multiply Byte 3 Operand

A4       MULW2          Multiply Word 2 Operand

A5       MULW3          Multiply Word 3 Operand

C4       MULL2           Multiply Long 2 Operand

C5       MULL3           Multiply Long 3 Operand

44        MUIF2            Multiply Floating 2 Operand

45        MULF3           Multiply Floating 3 Operand

64        MULD2           Multiply Double 2 Operand

65        MULD3           Multiply Double 3 Operand

Description

In 2 operand format, the product operand is multiplied by the multiplier operand and the product operand is replaced by the result. In 3 operand format, the multiplicand operand is multiplied by the multiplier operand and the product operand is replaced by the result. In floating format, the product operand result is rounded for both 2 and 3 operand format.

Notes

1. Integer overflow occurs if the high half of the double length result is not equal to the sign extension of the low half. On integer overflow, the product operand is replaced by the low order bits of the true result.

2. On a floating reserved operand fault, the product operand is unaffected and the condition codes are unpredictable.

3. On floating underflow, the product operand is replaced by 0.

4. On floating overflow, the product operand is replaced by an operand of all bits 0 except for a sign bit of 1 (a re served operand). Nß 1: Z ß 0; V ß 1; and C ß 0.