5.7.7.27 Optimize-sibling-calls Option
The -foptimize-sibling-calls option optimizes sibling calls (where the last
action of a function is a call to another function whose stack footprint is compatible
with the callee) and tail recursive calls (where the last action of a function is a call
to itself).
This option is automatically enabled at optimization levels -O2,
-O3, and -Os.
The -foptimize-sibling-calls form of this option will not enable these
optimizations.
