3.6.6 Options for Controlling Optimization

The options listed below control compiler optimizations and are described in following sections.

Table 3-16. General Optimization Options
Option (links to explanatory section)	Builds with
`-O0`	No optimizations (default).
`-O1` `-O`	Optimization level 1.
`-O2`	Optimization level 2.
`-O3`	Speed-orientated Optimizations.
`-Og`	Better debugging.
`-Os`	Size-orientated optimizations.
`-f[no-]data-sections`	Each data object assigned to its own section.
`-f[no-]fat-lto-objects`	Both object code and an internal representation written to the object files.
`-f[no-]function-sections`	Each function assigned to its own section.
`-m[no-]gas-isr-prologues`	Optimized context switch code for small interrupt service routines.
`-f[no-]inline-functions`	Integration of all simple functions into their callers.
`-f[no-]lto`	The standard link-time optimizer.
`-flto-partition=algorithm`	The specified algorithm to partition object files when running the link-time optimizer.
`-f[no-]omit-frame-pointer`	The stack pointer used in preference to the frame pointer.
`--nofallback`	No longer has any effect and is ignored by the compiler.
`-mno-pa-on-file=filename`	Procedural abstraction disabled for the specified file.
`-mno-pa-on-function=function`	Procedural abstraction disabled for the specified function.
`-mno-pa-outline-calls`	Procedural abstraction disabled across function calls.
`-m[no-]pa`	Procedural abstraction.
`-mpa-callcost-shortcall`	More aggressive procedural abstraction.
`-mpa-iterations=n`	The specified number of procedural abstraction iterations.
`-m[no-]reorder-stack-vars`	Reordered stack objects in the local frame.
`-f[no-]section-anchors`	Static objects accessed relative to one symbol.
`-f[no-]unroll-[all-]loops`	Loops unrolled to improve execution speed.
`-f[no-]use-linker-plugin`	A linker plugin with link-time optimizations.
`-f[no-]whole-program`	The whole-program optimizations.