5.7.7.37 Peephole/peephole2 Options

The -fpeephole option enables machine-specific peephole optimizations. Peephole optimizations occur at various points during the compilation. This is the default action if no option is specified.

The -fpeephole2 form of this option enables high-level peephole optimizations. This option is enabled at optimization levels -O2, -O3, and -Os.

The -fno-peephole and -fno-peephole2 form of these options disables standard and high-level peephole optimizations, respectively. Both options should be used to entirely disable peephole optimizations.