1. A method of data processing, said method comprising: compiling a plurality of instructions to obtain program code executable by a processor, wherein the compiling includes determining expected utilization of demand-fetched data and, based on the determining, associating at least one of a plurality of load instructions in the program code with a hint in the program code indicating that less than a full cache line of data is to be retrieved from a memory hierarchy associated with the processor; during execution of program code by the processor, the processor detecting whether a load instruction among the plurality of load instructions within the program code is associated by the program code with the hint within the program code; in response to detecting that the load instruction is not associated with the hint, the processor performing a demand fetch to retrieve a full cache line of data from the memory hierarchy into the processor in response to the load instruction; and in response to detecting that the load instruction is associated by the program code with the hint within the program code, the processor performing a demand fetch to retrieve a partial cache line of data into the processor from the memory hierarchy in response to the load instruction.