Editing Optimizing compiler (section)

=== Interprocedural optimizations ===
[[Interprocedural optimization]] works on the entire program, across procedure and file boundaries. It works tightly with intraprocedural counterparts, carried out with the cooperation of a local part and a global part. Typical interprocedural optimizations are procedure [[inlining]], interprocedural dead-code elimination, interprocedural constant propagation, and procedure reordering. As usual, the compiler needs to perform interprocedural analysis before its actual optimizations. Interprocedural analyses include alias analysis, [[array access analysis]], and the construction of a [[call graph]].

Interprocedural optimization is common in modern commercial compilers from [[Silicon Graphics|SGI]], [[Intel]], [[Microsoft]], and [[Sun Microsystems]]. For a long time, the open source [[GNU Compiler Collection|GCC]] was criticized for a lack of powerful interprocedural analysis and optimizations, though this is now improving.<ref>{{Cite arXiv|last=Glazunov|first=N. M.|date=November 25, 2012|title=Foundations of Scientific Research|class=cs.OH|eprint=1212.1651}}</ref> Another open-source compiler with full analysis and optimization infrastructure is [[Open64]].

Due to the extra time and space required by interprocedural analysis, most compilers do not perform it by default. Users must use compiler options explicitly to tell the compiler to enable interprocedural analysis and other expensive optimizations.