Inline expansion: when and how?

Abstract

Inline function expansion is an optimization that may improve program performance by removing calling sequences and enlarging the scope of other optimizations. Unfortunately it also has the drawback of enlarging programs. This might impair executable programs performance. In order to get rid of this annoying effect, we present, an easy to implement, inlining optimization that minimizes code size growth by combining a compile-time algorithm deciding when expansion should occur with different expansion frameworks describing how they should be performed. We present the experimental measures that have driven the design of inline function expansion. We conclude with measurements showing that our optimization succeeds in producing faster codes while avoiding code size increase.