CSNEG Conditional select negation This instruction returns, in the destination register, the value of the first source register if the condition is TRUE, and otherwise returns the negated value of the second source register. This instruction is a data-independent-time instruction as described in About PSTATE.DIT. This instruction is used by the alias CNEG !(cond IN {'111x'}) && Rn == Rm See below for details of when the alias is preferred. 1 0 1 1 0 1 0 1 0 0 0 1 0 CSNEG <Wd>, <Wn>, <Wm>, <cond> 1 CSNEG <Xd>, <Xn>, <Xm>, <cond> let d : integer{} = UInt(Rd); let n : integer{} = UInt(Rn); let m : integer{} = UInt(Rm); let datasize : integer{} = 32 << UInt(sf); let condition : bits(4) = cond; <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, encoded in the "Rn" field. <Wm> Is the 32-bit name of the second general-purpose source register, encoded in the "Rm" field. <cond> Is one of the standard conditions, encoded in the standard way, and cond <cond> 0000 EQ 0001 NE 0010 CS 0011 CC 0100 MI 0101 PL 0110 VS 0111 VC 1000 HI 1001 LS 1010 GE 1011 LT 1100 GT 1101 LE 1110 AL 1111 NV <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, encoded in the "Rn" field. <Xm> Is the 64-bit name of the second general-purpose source register, encoded in the "Rm" field. Alias Conditions var result : bits(datasize); if ConditionHolds(condition) then result = X{datasize}(n); else result = NOT(X{datasize}(m)) + 1; end; X{datasize}(d) = result; 2026-03-12 12:23:09 2025-09_rel_asl1