Instructions may require one or more operands to be executed, which may be provided from a register file. In the context of a GPU, however, a register file may be a relatively large structure, and reading from the register file may be energy and/or time intensive An operand cache may be used to store a subset of operands, and may use less power and have quicker access times than the register file. Hint values may be used in some embodiments to suggest that a particular operand should be stored in the operand cache (so that is available for current or future use). In one embodiment, a hint value indicates that an operand should be cached whenever possible. Hint values may be determined by software, such as a compiler, in some embodiments. One or more criteria may be used to determine hint values, such as how soon in the future or how frequently an operand will be used again.