Using HLO

Use the -O3 option.

For IA-32 architecture, the Intel® Pentium® III processor and subsequent processors support data prefetching. To use the -O3 option with these processors, you must also use the -QxK or -QaxK options for the Pentium III processor, or the -QxW or -QaxW options for the Pentium 4 processor and subsequent 32-bit processors.

Example

prompt>icl -O3 -QaxW myprog.cpp