<operation>{cond}{S} Rd, Rm, Rs {, Rn}

<operation>

MUL multiply

Rd := Rm × Rs

MLA multiply with accumulate

Rd := Rn + (Rm × Rs)

The multiply instructions produce the same result for both signed and unsigned values.

Specifying the same register for Rm and Rs has UNPREDICTABLE results. UNPREDICTABLE means that the result of an instruction cannot be relied upon.

<operation>{cond}{S} RdLo, RdHi, Rm, Rs

64-bit result output into two registers.

<operation>

UMULL unsigned multiply long

RdHi, RdLo := Rm × Rs

UMLAL unsigned multiply with accumlate long

RdHi, RdLo := RdHi,RdLo + (Rm × Rs)

SMULL signed multiply long

RdHi, RdLo := Rm × Rs

SMLAL signed multiply with accumlate long

RdHi, RdLo := RdHi,RdLo + (Rm × Rs)

Note that they have the same form, but they treat the sign bit differently.