1. A computer program product for replacing an atomic sequence, the computer program product comprising: a non-transitory storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising: receiving, by the processing circuit, the atomic sequence; detecting, by the processing circuit, the atomic sequence; and generating, by the processing circuit, an internal atomic operation to replace the atomic sequence; based on separate instructions of the atomic sequence not being a same group and based on the separate instructions being positioned to execute separately, configuring an instruction decoder to perform instruction cache marking of the separate instructions that are not in the same group to force a load reserve instruction and a store conditional instruction into the same group; configuring the instruction decoder to initially mark the load reserve instruction based on the load reserve instruction being detected first in the separate instructions or initially mark the store conditional instruction based on the store conditional instruction being detected first in the separate instructions; configuring the instruction decoder to complete formation of the same group by marking the load reserve instruction based on the load reserve instruction being detected last in the separate instructions or by marking the store conditional instruction based on the store conditional instruction being detected last in the separate instructions; and configuring the instruction decode to translate the separate instructions having been grouped into the same group for the atomic sequence into the internal atomic operation.