MSUB Multiply-subtract This instruction multiplies two register values, subtracts the product from a third register value, and writes the result to the destination register. 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. This instruction is used by the alias MNEG Ra == '11111' See below for details of when the alias is preferred. 0 0 1 1 0 1 1 0 0 0 1 0 MSUB <Wd>, <Wn>, <Wm>, <Wa> 1 MSUB <Xd>, <Xn>, <Xm>, <Xa> constant integer d = UInt(Rd); constant integer n = UInt(Rn); constant integer m = UInt(Rm); constant integer a = UInt(Ra); constant integer datasize = 32 << UInt(sf); <Wd> Is the 32-bit name of the general-purpose destination register, encoded in the "Rd" field. <Wn> Is the 32-bit name of the first general-purpose source register holding the multiplicand, encoded in the "Rn" field. <Wm> Is the 32-bit name of the second general-purpose source register holding the multiplier, encoded in the "Rm" field. <Wa> Is the 32-bit name of the third general-purpose source register holding the minuend, encoded in the "Ra" field. <Xd> Is the 64-bit name of the general-purpose destination register, encoded in the "Rd" field. <Xn> Is the 64-bit name of the first general-purpose source register holding the multiplicand, encoded in the "Rn" field. <Xm> Is the 64-bit name of the second general-purpose source register holding the multiplier, encoded in the "Rm" field. <Xa> Is the 64-bit name of the third general-purpose source register holding the minuend, encoded in the "Ra" field. Alias Conditions constant bits(datasize) operand1 = X[n, datasize]; constant bits(datasize) operand2 = X[m, datasize]; constant bits(datasize) operand3 = X[a, datasize]; constant integer result = UInt(operand3) - (UInt(operand1) * UInt(operand2)); X[d, datasize] = result<datasize-1:0>;