forwprop: Change test in loop of optimize_memcpy_to_memset

This was noticed in the review of copy propagation for aggregates
patch, instead of checking for a NULL or a non-ssa name of vuse,
we should instead check if it the vuse is a default name and stop
then.

Bootstrapped and tested on x86_64-linux-gnu.

gcc/ChangeLog:

	* tree-ssa-forwprop.cc (optimize_memcpy_to_memset): Change check
	from NULL/non-ssa name to default name.

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

diff --git a/gcc/tree-ssa-forwprop.cc b/gcc/tree-ssa-forwprop.cc
index 4c048a9a2986803d35adb6e7308834b1c19aae87..e457a69ed489ae5334d2b611b8683d7b60ccb98b 100644 (file)
--- a/gcc/tree-ssa-forwprop.cc
+++ b/gcc/tree-ssa-forwprop.cc
@@ -1226,7 +1226,8 @@ optimize_memcpy_to_memset (gimple_stmt_iterator *gsip, tree dest, tree src, tree
   gimple *defstmt;
   unsigned limit = param_sccvn_max_alias_queries_per_access;
   do {
-    if (vuse == NULL || TREE_CODE (vuse) != SSA_NAME)
+    /* If the vuse is the default definition, then there is no stores beforhand. */
+    if (SSA_NAME_IS_DEFAULT_DEF (vuse))
       return false;
     defstmt = SSA_NAME_DEF_STMT (vuse);
     if (is_a <gphi*>(defstmt))