-qkeepparm

A function usually stores its incoming parameters on the stack. In IBM® XL C/C++ for AIX® 16.1.0 or earlier releases, when -qnokeepparm is enabled with an optimization level -O2 or higher, parameters are removed from the stack if this provides an optimization advantage.

The -msave-reg-params option in the IBM Open XL C/C++ 17.1.3 compiler has functionality similar to -qkeepparm. However, when -msave-reg-params is disabled, parameters are removed from the stack if this provides an optimization advantage, regardless of whether optimization is enabled.