28 Document Revision History

Revision A (June 2019)

Updated library information to reflect recent changes, including the Microchip Unified Standard Library
Corrected examples of using the __pack specifier
Removed 'How To' on the cause or reset, which was not appropriate for PIC32C/SAM devices
Updated the size of floating-point types to reflect recent compiler changes
Updated information on how to ensure a function is not removed
Updated information relating to using a debugger
Updated information on the compiler option controls available in the MPLAB X IDE
Updated information on the runtime startup code, including information on the data initialization template
Provided dedicated sections on all compiler options in addition to a summary table
Added new information on -mdfp, -mpure-code, -feliminate-unused-debug-symbols, -Og, and --dinit-compress options
Some options and description were not relevant for PIC32/SAM devices and were removed
Added divergences from the C99 language standard
Expanded configuration bit access information
Improved information on tightly coupled memories
Added used variable attribute
Added externally_visible and nopa function attributes
Added information on placing code in eXecute Only Memory (XOM)
Updated information on interrupt context switch
Improved information on smart IO features
Many general corrections and improvements

Updated references to the C++ standard to reflect that the ISO/IEC 14882:2014 C++ program language is now supported
Defined the compiler's implementation-defined behavior for the C++14 standard in a new section
Included additional information on interrupt operation
Removed the CCI chapter and references to this, as CCI is not supported for C/SAM devices and the feature is disabled in the MPLAB X IDE

Added new How To explaining how the stack usage for each function in a module can be displayed
Added new How To showing how to prevent a program's checksum to change
Added summary of supported Arm architectures and cores
Removed reference to the unsupported -mreserve option from a How To
Updated compiler options used with the Linktime Optimizations setting in XC32 Global options tab of the MPLAB X IDE Project Properties
Added option present in the xc32-ar (Library Archive) tab of the MPLAB X IDE Project Properties
Added a diagram indicating the internal compiler applications

Added the following options to the guide:

Corrected typo in the name of what should have been the --dint-compression option and specified this with the -Wl, prefix, since it is a linker option
Added tcm variable attribute
Removed erroneous text and corrected the example in the Variables in Register section
Updated the Dynamic Memory Allocation section to include the new allocation schemes
Updated the runtime startup code section to include the on-exit feature