tree-ssa-dom.c (record_equivalences_from_phis): Add a comment.

	* tree-ssa-dom.c (record_equivalences_from_phis): Add a
	comment.

From-SVN: r92091

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6768b17ed09c8f29ffa7a0b3e1baf6d8c3eb0d72..d991115892ad3da5b6aebdc775b35cb02bfffe4f 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -3,6 +3,9 @@
        * tree-ssa-dom.c (record_equivalences_from_phis): Speed up by
        doing a pointer comparison.
 
+       * tree-ssa-dom.c (record_equivalences_from_phis): Add a
+       comment.
+
 2004-12-13  Kazuhiro Inaoka <inaoka.kazuhiro@renesas.com>
 
        * config/m32r/t-linux (SHLIB_MAPFILES): Add libgcc-glibc.ver to

diff --git a/gcc/tree-ssa-dom.c b/gcc/tree-ssa-dom.c
index def20d6539d7b8d62ee8dfdd763278322da8558e..5c6097939e50870205a7cad78f1707e0d7bb22ae 100644 (file)
--- a/gcc/tree-ssa-dom.c
+++ b/gcc/tree-ssa-dom.c
@@ -1177,7 +1177,9 @@ record_equivalences_from_phis (basic_block bb)
        {
          tree t = PHI_ARG_DEF (phi, i);
 
-         /* Ignore alternatives which are the same as our LHS.  */
+         /* Ignore alternatives which are the same as our LHS.  Since
+            LHS is a PHI_RESULT, it is known to be a SSA_NAME, so we
+            can simply compare pointers.  */
          if (lhs == t)
            continue;