When working on PR121279, I noticed that lim would create an uninitialized decl and marking it with supression for uninitialization warning. This is fine but then into ssa would just call get_or_create_ssa_default_def on that new decl which could in theory take some extra compile time to figure that out. Plus when doing the rewriting for undefinedness, there would now be a VCE around the decl. This means the ssa name is kept around and not propagated in some cases. So instead this patch manually calls get_or_create_ssa_default_def to get the "uninitalized" ssa name for this decl and no longer needs the write into ssa nor for undefined ness.
Bootstrapped and tested on x86_64-linux-gnu. gcc/ChangeLog: * tree-ssa-loop-im.cc (execute_sm): Call get_or_create_ssa_default_def for the new uninitialized decl. Signed-off-by: Andrew Pinski <andrew.pin...@oss.qualcomm.com> --- gcc/tree-ssa-loop-im.cc | 1 + 1 file changed, 1 insertion(+) diff --git a/gcc/tree-ssa-loop-im.cc b/gcc/tree-ssa-loop-im.cc index aee419aa5b1..0340857058b 100644 --- a/gcc/tree-ssa-loop-im.cc +++ b/gcc/tree-ssa-loop-im.cc @@ -2355,6 +2355,7 @@ execute_sm (class loop *loop, im_mem_ref *ref, loop entry as not to be warned for. */ tree uninit = create_tmp_reg (TREE_TYPE (aux->tmp_var)); suppress_warning (uninit, OPT_Wuninitialized); + uninit = get_or_create_ssa_default_def (cfun, uninit); load = gimple_build_assign (aux->tmp_var, uninit); } lim_data = init_lim_data (load); -- 2.43.0