fold-const.c (tree_swap_operands_p): Treat SSA_NAMEs like DECLs but prefer SSA_NAMEs over DECLs.

2007-02-16  Richard Guenther  <rguenther@suse.de>
	Christian Bruel  <christian.bruel@st.com>

	* fold-const.c (tree_swap_operands_p): Treat SSA_NAMEs like
	DECLs but prefer SSA_NAMEs over DECLs.

	* gcc.dg/strict-overflow-5.c: New testcase.

Co-Authored-By: Christian Bruel <christian.bruel@st.com>

From-SVN: r122040

gcc/ChangeLog

 2007-02-16  Richard Guenther  <rguenther@suse.de>
+	Christian Bruel  <christian.bruel@st.com>
+
+	* fold-const.c (tree_swap_operands_p): Treat SSA_NAMEs like
+	DECLs but prefer SSA_NAMEs over DECLs.
+
+2007-02-16  Richard Guenther  <rguenther@suse.de>
 
 	* tree-flow-inline.h (single_imm_use_p): Remove.
 	(zero_imm_uses_p): Likewise.

gcc/fold-const.c

@@ -6673,11 +6673,6 @@ tree_swap_operands_p (tree arg0, tree arg1, bool reorder)
       && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
     return 0;
 
-  if (DECL_P (arg1))
-    return 0;
-  if (DECL_P (arg0))
-    return 1;
-
   /* It is preferable to swap two SSA_NAME to ensure a canonical form
      for commutative and comparison operators.  Ensuring a canonical
      form allows the optimizers to find additional redundancies without
@@ -6687,6 +6682,18 @@ tree_swap_operands_p (tree arg0, tree arg1, bool reorder)
       && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
     return 1;
 
+  /* Put SSA_NAMEs last.  */
+  if (TREE_CODE (arg1) == SSA_NAME)
+    return 0;
+  if (TREE_CODE (arg0) == SSA_NAME)
+    return 1;
+
+  /* Put variables last.  */
+  if (DECL_P (arg1))
+    return 0;
+  if (DECL_P (arg0))
+    return 1;
+
   return 0;
 }
 

gcc/testsuite/ChangeLog

+2007-02-16  Richard Guenther  <rguenther@suse.de>
+	Christian Bruel  <christian.bruel@st.com>
+
+	* gcc.dg/strict-overflow-5.c: New testcase.
+
 2007-02-16  Tobias Burnus  <burnus@net-b.de>
 
 	PR fortran/30793

gcc/testsuite/gcc.dg/strict-overflow-5.c

+/* { dg-do compile } */
+/* { dg-options "-fstrict-overflow -O2 -fdump-tree-final_cleanup" } */
+
+/* We can only unroll when using strict overflow semantics.  */
+
+int foo (int i)
+{
+  int index;
+  int r=0;
+ 
+  for (index = i; index <= i+4; index+=2) 
+    r++;
+ 
+  return r;
+}
+
+/* { dg-final { scan-tree-dump-times "r = 3" 1 "final_cleanup" } } */
+/* { dg-final { cleanup-tree-dump "final_cleanup" } } */
+