Encoding:

SPECIAL

000000

0

00 0000 0000

rd

0

00000

MFHI

010000

6

10

5

5

6

Format: 

MFHI  rd

MIPS32, removed in Release 6

Move From HI Register

Purpose:

Move From HI Register

To copy the special purpose HI register to a GPR.

Description: 

 GPR[rd] = HI

The contents of special register HI are loaded into GPR rd.

Restrictions:

Availability and Compatibility:

This instruction has been removed in Release 6.

Operation: 

GPR[rd] = HI

Exceptions:

None

Historical Information:

In the MIPS I, II, and III architectures, the two instructions which follow the MFHI must not modify the HI register.

If this restriction is violated, the result of the MFHI is UNPREDICTABLE. This restriction was removed in MIPS

IV and MIPS32, and all subsequent levels of the architecture.