-fipa-struct-dfc,-fipa-struct-dfc-bitfield,-fipa-struct-dfc-shadow

Description

• -fipa-struct-dfc: optimizes the compression of dynamic members in a structure. Parts of the original program are cloned as new program branches. In these new branches, the structure members that receive runtime input data are heuristically compressed. Whether a structure member can enter the new branch is determined based on the check result of the input data range at runtime.
• -fipa-struct-dfc-bitfield: sub-option for optimizing the compression of dynamic members in a structure. After this option is enabled, a member to be compressed can be heuristically selected and compressed into a bit field.
• -fipa-struct-dfc-shadow: sub-option for optimizing the compression of dynamic members in a structure. After this option is enabled, dynamic member hiding is activated, and a better policy is used to hide duplicate members.

Usage

Add the following content to the option:

-O3 -flto -flto-partition=one -fipa-struct-reorg=2 -fipa-struct-dfc -fipa-struct-dfc-bitfield -fipa-struct-dfc-shadow

The -fipa-struct-dfc option can be enabled only when -O3 -flto -flto-partition=one is set and the -fipa-struct-reorg level is 2 or higher (or -fipa-reorder-fields is used).

The -fipa-struct-dfc-bitfield and -fipa-struct-dfc-shadow options can be enabled only when the -fipa-struct-dfc option is enabled.