Use Built-in Functions

This tip has been extracted from the main Built-in Functions article.

All three Microchip MPLAB® XC compilers provide built-in functions that implement a variety of device-specific tasks. These offer several benefits over hand-written, in-line assembly code, and they should always be used in preference to in-line assembly.

The assembly code generated from built-in functions directly implements the desired task, making them very efficient, yet providing the same code abstraction as functions. Optimizations are typically enabled for the output of built-in functions, unlike in-line assembly code, and register usage of the built-in function is taken into consideration by the compiler, which ensures that the code works with the surrounding compiler-generated code—a common failure of handwritten in-line assembly code.

Check the Appendixes in your compiler’s User’s Guide to find out what built-in functions are available before attempting to revert to assembly code.

© 2016 Microchip Technology, Inc.
Information contained on this site regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer's risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights.