USMMLA (vector) Unsigned and signed 8-bit integer matrix multiply-accumulate (vector) This instruction multiplies the 2x8 matrix of unsigned 8-bit integer values in the first source vector by the 8x2 matrix of signed 8-bit integer values in the second source vector. The resulting 2x2 32-bit integer matrix product is destructively added to the 32-bit integer matrix accumulator in the destination vector. This is equivalent to performing an 8-way dot product per destination element. From Armv8.2 to Armv8.5, this is an OPTIONAL instruction. From Armv8.6 it is mandatory for implementations that include Advanced SIMD to support it. ID_AA64ISAR1_EL1.I8MM indicates whether this instruction is supported. If PSTATE.DIT is 1: The execution time of this instruction is independent of: The values of the data supplied in any of its registers. The values of the NZCV flags. The response of this instruction to asynchronous exceptions does not vary based on: The values of the data supplied in any of its registers. The values of the NZCV flags. Arm expects that the USMMLA (vector) instruction will deliver a peak integer multiply throughput that is at least as high as can be achieved using two USDOT (vector) instructions, with a goal that it should have significantly higher throughput. 0 1 0 0 1 1 1 0 1 0 0 1 0 1 0 1 1 USMMLA <Vd>.4S, <Vn>.16B, <Vm>.16B if !IsFeatureImplemented(FEAT_I8MM) then UNDEFINED; constant integer d = UInt(Rd); constant integer n = UInt(Rn); constant integer m = UInt(Rm); constant boolean op1_unsigned = TRUE; constant boolean op2_unsigned = FALSE; <Vd> Is the name of the SIMD&FP third source and destination register, encoded in the "Rd" field. <Vn> Is the name of the first SIMD&FP source register, encoded in the "Rn" field. <Vm> Is the name of the second SIMD&FP source register, encoded in the "Rm" field. CheckFPAdvSIMDEnabled64(); constant bits(128) operand1 = V[n, 128]; constant bits(128) operand2 = V[m, 128]; constant bits(128) addend = V[d, 128]; V[d, 128] = MatMulAdd(addend, operand1, operand2, op1_unsigned, op2_unsigned);