-qcompact

In z/OS® XL C/C++, the -qcompact option avoids optimizations that increase code size.

In Open XL C/C++ for z/OS, the -Oz or -Os option provides a similar function to control output code size. -Oz and -Os are based on the -O2 optimization level. When you specify -O3 -Os, -O3 is overridden. When you specify -Os -O2, -Os is overridden.

When you migrate your program from z/OS XL C/C++ to Open XL C/C++ for z/OS, reevaluate the size of the output generated by Open XL C/C++ for z/OS. If reduction in code size is required, try using the -Os option and note any performance trade-offs. If further reduction in code size is required, try using the -Oz option.