Assembler Language Reference

mulhd (Multiply High Double Word) Instruction

Purpose

Multiply two 64-bit values together. Place the high-order 64 bits of the result into a register.

Syntax

Bits	Value
0-5	31
6-10	D
11-15	A
16-20	B
21	0
22-30	73
31	Rc

POWER family
mulhd	RT, RA, RB (Rc=0)
mulhd.	RT, RA, RB (Rc=1)

Description

The 64-bit operands are the contents of general purpose registers (GPR) RA and RB. The high-order 64 bits of the 128-bit product of the operands are placed into RT.

Both the operands and the product are interpreted as signed integers.

This instruction may execute faster on some implementations if RB contains the operand having the smaller absolute value.

Parameters

RT	Specifies target general-purpose register for the result of the computation.
RA	Specifies source general-purpose register for an operand.
RB	Specifies source general-purpose register for an operand.

Implementation

This instruction is defined only for 64-bit implementations. Using it on a 32-bit implementation will cause the system illegal instruction error handler to be invoked.