Instructions and logic provide for a Single Instruction Multiple Data (SIMD) SM4 round slice operation. Embodiments of an instruction specify a first and a second source data operand set, and substitution function indicators, e.g. in an immediate operand. Embodiments of a processor may include encryption units, responsive to the first instruction, to: perform a slice of SM4-round exchanges on a portion of the first source data operand set with a corresponding keys from the second source data operand set in response to a substitution function indicator that indicates a first substitution function, perform a slice of SM4 key generations using another portion of the first source data operand set with corresponding constants from the second source data operand set in response to a substitution function indicator that indicates a second substitution function, and store a set of result elements of the first instruction in a SIMD destination register.