Encoding:

Format:

DSHD rd, rt

Purpose:

Doubleword Swap Halfwords Within Doublewords

To swap the halfwords of GPR rt and store the value into GPR rd.

Description:

 GPR[rd] = SwapHalfwordsWithinDoublewords(GPR[rt])

The halfwords of GPR rt are swapped and stored in GPR rd.

Restrictions:

In implementations of Release 1 of the architecture, this instruction resulted in a Reserved Instruction exception.

Operation:

GPR[rd] = GPR[rt]15..0 || GPR[rt]31..16 || GPR[rt]47..32 || GPR[rt]63..48

Exceptions:

Reserved Instruction

Programming Notes:

The DSBH and DSHD instructions can be used to convert doubleword data of one endianness to the other endianness.

For example:

ld    t0, 0(a1)           /* Read doubleword value */
dsbh  t0, t0              /* Convert endiannes of the halfwords */
dshd  t0, t0              /* Swap the halfwords within the doublewords */