-qcompact

Category

Optimization and tuning

Purpose

Avoids optimizations that increase code size.

Defaults

-qnocompact

Usage

By default, some techniques the optimizer uses to improve performance, such as loop unrolling and array vectorization, may also make the program larger. For systems with limited storage, you can use -qcompact to reduce the expansion that takes place. If your program has many loop and array language constructs, using the -qcompact option will affect your application's overall performance. You may want to restrict using this option to those parts of your program where optimization gains will remain unaffected.

Rules

With -qcompact in effect, -qinline and other optimization options still work; the reductions in code size come from limiting code replication that is done automatically during optimization.

This option takes effect only when it is specified at the -O2 optimization level, or higher.