vect: release defs of removed statement

While trying to add use of simple_dce_from_worklist
to the vectorizer so we don't need to run a full blown
DCE pass after the vectorizer, there was a crash noticed
due to a ssa name which has a stmt without a bb. This was
due to not calling release_defs after the call to gsi_remove.

Note the code to remove zero use statements should be able to
remove once the use of simple_dce_from_worklist has been added.
But in the meantime, fixing this bug will also improve memory
usage and a few other things which look through all ssa names.

gcc/ChangeLog:

	* tree-vect-loop.cc (optimize_mask_stores): Call release_defs
	after the call to gsi_remove with last argument of true.

Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>

diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
index cc15492f6a01328f62bffcb6d060c201555e8ddd..62c7f90779fa89ad312c34137f025657d3f2d4e8 100644 (file)
--- a/gcc/tree-vect-loop.cc
+++ b/gcc/tree-vect-loop.cc
@@ -12803,6 +12803,7 @@ optimize_mask_stores (class loop *loop)
                  if (has_zero_uses (lhs))
                    {
                      gsi_remove (&gsi_from, true);
+                     release_defs (stmt1);
                      continue;
                    }
                }