1. A method of executing a machine instruction in a computing environment, said computer program product comprising: obtaining, by a processor, a machine instruction for execution, the machine instruction being defined for computer execution according to a computer architecture, the machine instruction comprising: an operation code field having an operation code to specify a conditional instruction end operation; and executing, by the processor, the machine instruction, the executing comprising: obtaining an operand; determining whether the operand has a predetermined relationship with respect to a value; based on determining that the operand does not have the predetermined relationship with respect to the value, repeating the obtaining and the determining; based on determining that the operand has the predetermined relationship with respect to the value, completing execution of the instruction; and wherein the obtaining the operand, the determining whether the operand has the predetermined relationship with respect to the value, the based on determining that the operand does not have the predetermined relationship with respect to the value, repeating the obtaining and the determining, and the based on determining that the operand has the predetermined relationship with respect to the value, completing execution of the instruction are performed as part of a single instruction having the operation code.