Change Details

Imported functions and variables get the visibility from the prevailing module. However, non-prevailing definitions do not get the visibility. This patch adds visibility bits to GlobalValueSummary::GVFlags so that non-prevailing definitions can get the most constraining visibility from the prevailing definitions. Protected/hidden can imply dso_local which can enable some optimizations (this is stronger than GVFlags::DSOLocal because the implied dso_local can be leveraged for ELF -shared while default visibility dso_local has to be cleared for ELF -shared). Note: if a declaration has the most constraining visibility, the result visibility may not be that one because we don't track visibility from declarations.

Imported functions and variables get the visibility from the prevailing module. However, non-prevailing and prevailing definitions do not get the visibility from the most constraining visibility among all modules. This patch * adds visibility bits to GlobalValueSummary::GVFlags * (for ELF) computes the most constraining visibility among all definitions and propagates it to all definitions Protected/hidden can imply dso_local which can enable some optimizations (this is stronger than GVFlags::DSOLocal because the implied dso_local can be leveraged for ELF -shared while default visibility dso_local has to be cleared for ELF -shared). Note: the visibility from a declaration is not tracked, so if a declaration has the most constraining visibility, the result visibility may not be that one.

Imported functions and variables get the visibility from the prevailing module. However, non-prevailing definitions do not get the visibility. This patch adds visibility bits to GlobalValueSummary::GVFlags so thamodule. However, non-prevailing and prevailing definitions do not get non-prevailing definitions can get the most constraining visibility from thethe visibility from the most constraining visibility among all modules. This patch * adds visibility bits to GlobalValueSummary::GVFlags prevailing* (for ELF) computes the most constraining visibility among all definitions. ns and propagates it to all definitions Protected/hidden can imply dso_local which can enable some optimizations (this some optimizations (this is stronger than GVFlags::DSOLocal because the implied dso_local can be dso_local can be leveraged for ELF -shared while default visibility dso_local has to be cleared has to be cleared for ELF -shared). Note: if a declaration has the most constraining visibilitythe visibility from a declaration is not tracked, the result visibility may not be that one because we don't track visibility fromso if a declaration has declarationsthe most constraining visibility, the result visibility may not be that one.