Architecture

Table 3-8. Multiply, multiply / add instructions (R3000A extended instruction set)

MULT, MULTU, MADD, MADDU (ISA extended set)

Instruction

Format and Description

 

 

 

 

 

 

 

 

op

rs

rt

rd

 

0

funct

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Multiply

MULT rd, rs, rt

 

 

 

 

 

 

 

 

 

Multiply the contents of registers rs and rt as two’s complement integers, and

 

store the doubleword (64-bit) result in multiply/divide registers HI and LO.

 

Also, store the lower 32 bits in register rd.

 

 

 

 

 

 

Multiply

MULTU rd, rs, rt

 

 

 

 

 

 

 

 

Unsigned

Multiply the contents of registers rs and rt as unsigned integers, and store the

 

doubleword (64-bit) result in multiply/divide registers HI and LO. Also, store

 

the lower 32 bits in register rd.

 

 

 

 

 

 

 

Multiply ADD

MADD rd, rs, rt

 

 

 

 

 

 

 

 

 

MADD rs, rt

 

 

 

 

 

 

 

 

 

Multiply the contents of registers rs and rt as two’s complement integers, and

 

add the doubleword (64-bit) result to multiply/divide registers HI and LO.

 

Also, store the lower 32 bits of the add result in register rd. In the MADD rs, rt

 

format, the store operation to a general register is omitted.

 

 

 

Multiply ADD

MADDU rd, rs, rt

 

 

 

 

 

 

 

 

Unsigned

MADDU rs, rt

 

 

 

 

 

 

 

 

 

Multiply the contents of registers rs and rt as unsigned integers, and add the

 

doubleword (64-bit) result to multiply/divide registers HI and LO. Also, store the

 

lower 32 bits of the add result in register rd. In the MADDU rs, rt format, the

 

store operation to a general register is omitted.

 

 

 

 

 

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