9.10.16 reverse (alignment)

The reverse attribute specifies a minimum alignment for the ending address of a variable, plus one. The alignment is specified in bytes and must be a power of two. Reverse-aligned variables can be used for decrementing modulo buffers in dsPIC DSC assembly language. This attribute could be useful if an application defines variables in C that will be accessed from assembly language.

int buf1[128] __attribute__ ((reverse(256)));

The reverse attribute conflicts with the aligned and section attributes. An attempt to name a section for a reverse-aligned variable will be ignored with a warning. It is an error condition to specify both reverse and aligned for the same variable. A variable with the reverse attribute cannot be placed into the auto_psv space (see the space() attribute or the -mconst-in-code option); attempts to do so will cause a warning and the compiler will place the variable into the PSV space.