inline_bottom_up

Controls the bottom-up function inlining method.

  #pragma inline_bottom_up on | off | reset   

Bottom-up function inlining tries to expand up to eight levels of inline leaf functions. The maximum size of an expanded inline function and the caller of an inline function can be controlled by the pragmas shown in the following listings.

// Maximum complexity of an inlined function 
#pragma inline_max_size( 
max
 ) // default 
max
 == 256 

// Maximum complexity of a function that calls inlined functions 
#pragma inline_max_total_size( 
max
 ) // default 
max
 == 10000 

where max loosely corresponds to the number of instructions in a function.

If you enable this pragma, the compiler calculates inline depth from the last function in the call chain up to the first function that starts the call chain. The number of functions the compiler inlines from the bottom depends on the values of inline_depth, inline_max_size, and inline_max_total_size. This method generates faster and smaller source code for some (but not all) programs with many nested inline function calls.

If you disable this pragma, top-down inlining is selected, and the inline_depth setting determines the limits for top-down inlining. The inline_max_size and inline_max_total_size pragmas do not affect the compiler in top-down mode.