https://gcc.gnu.org/g:2e1dfaad2ae7f11e1ea16f5f419d82d6cbd50c3d
commit r16-3373-g2e1dfaad2ae7f11e1ea16f5f419d82d6cbd50c3d
Author: Andrew Pinski <andrew.pin...@oss.qualcomm.com>
Date: Tue Aug 19 14:52:18 2025 -0700
LIM: Manually put uninit decl into ssa
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>
Diff:
---
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 aee419aa5b1e..0340857058bb 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);
