https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103989
--- Comment #15 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:53ead5787921be799593232cfc9931f916b79002 commit r12-6550-g53ead5787921be799593232cfc9931f916b79002 Author: Jakub Jelinek <ja...@redhat.com> Date: Thu Jan 13 15:59:47 2022 +0100 inliner: Don't emit copy stmts for empty type parameters [PR103989] The following patch avoids emitting a parameter copy statement when inlining if the parameter has empty type. E.g. the gimplifier does something similar (except that it needs to evaluate side-effects if any, which isn't the case here): /* For empty types only gimplify the left hand side and right hand side as statements and throw away the assignment. Do this after gimplify_modify_expr_rhs so we handle TARGET_EXPRs of addressable types properly. */ if (is_empty_type (TREE_TYPE (*from_p)) && !want_value /* Don't do this for calls that return addressable types, expand_call relies on those having a lhs. */ && !(TREE_ADDRESSABLE (TREE_TYPE (*from_p)) && TREE_CODE (*from_p) == CALL_EXPR)) { gimplify_stmt (from_p, pre_p); gimplify_stmt (to_p, pre_p); *expr_p = NULL_TREE; return GS_ALL_DONE; } Unfortunately, this patch doesn't cure the uninit warnings in that PR, which is caused by ipa inlining happening even at -Og when the post-IPA -Og passes don't expect the need to clean up after ipa inlining, but I think is desirable anyway. 2022-01-13 Jakub Jelinek <ja...@redhat.com> PR tree-optimization/103989 * tree-inline.c (setup_one_parameter): Don't copy parms with empty type.
