Handle GIMPLE_ASSIGNs with different vuse in gimple_equal_p

2013-11-14  Tom de Vries  <tom@codesourcery.com>

	* tree-ssa-tail-merge.c (gimple_equal_p): Add test for structural
	equality for GIMPLE_ASSIGN.

	* gcc.dg/tail-merge-store.c: New test.

From-SVN: r204767

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 66d9c7b..dad20a4 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,10 @@
 2013-11-14  Tom de Vries  <tom@codesourcery.com>
 
+       * tree-ssa-tail-merge.c (gimple_equal_p): Add test for structural
+       equality for GIMPLE_ASSIGN.
+
+2013-11-14  Tom de Vries  <tom@codesourcery.com>
+
        * tree-ssa-tail-merge.c (gimple_operand_equal_value_p): Factor new
        function out of ...
        (gimple_equal_p): ... here.

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 93080a8..ddbb62e 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2013-11-14  Tom de Vries  <tom@codesourcery.com>
+
+       * gcc.dg/tail-merge-store.c: New test.
+
 2013-11-13  Andrew MacLeod  <amacleod@redhat.com>
 
        * testsuite/g++.dg/plugin/selfassign.c: Include gimple-iterator.h.

diff --git a/gcc/testsuite/gcc.dg/tail-merge-store.c b/gcc/testsuite/gcc.dg/tail-merge-store.c
new file mode 100644 (file)
index 0000000..1aefbdc
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tail-merge-store.c
@@ -0,0 +1,22 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -ftree-tail-merge -fdump-tree-pre" } */
+
+int z;
+int x;
+
+void
+f (int c, int d)
+{
+  if (c)
+    z = 5;
+  else
+    {
+      if (d)
+       x = 4;
+      z = 5;
+    }
+}
+
+/* { dg-final { scan-tree-dump-times "duplicate of" 1 "pre"} } */
+/* { dg-final { scan-tree-dump-times "z = 5" 1 "pre"} } */
+/* { dg-final { cleanup-tree-dump "pre" } } */

diff --git a/gcc/tree-ssa-tail-merge.c b/gcc/tree-ssa-tail-merge.c
index ca69b23..c97da97 100644 (file)
--- a/gcc/tree-ssa-tail-merge.c
+++ b/gcc/tree-ssa-tail-merge.c
@@ -1142,8 +1142,17 @@ gimple_equal_p (same_succ same_succ, gimple s1, gimple s2)
       lhs2 = gimple_get_lhs (s2);
       if (TREE_CODE (lhs1) != SSA_NAME
          && TREE_CODE (lhs2) != SSA_NAME)
-       return (vn_valueize (gimple_vdef (s1))
-               == vn_valueize (gimple_vdef (s2)));
+       {
+         /* If the vdef is the same, it's the same statement.  */
+         if (vn_valueize (gimple_vdef (s1))
+             == vn_valueize (gimple_vdef (s2)))
+           return true;
+
+         /* Test for structural equality.  */
+         return (operand_equal_p (lhs1, lhs2, 0)
+                 && gimple_operand_equal_value_p (gimple_assign_rhs1 (s1),
+                                                  gimple_assign_rhs1 (s2)));
+       }
       else if (TREE_CODE (lhs1) == SSA_NAME
               && TREE_CODE (lhs2) == SSA_NAME)
        return vn_valueize (lhs1) == vn_valueize (lhs2);