re PR middle-end/63743 (Thumb1: big regression for float operators by r216728)

2015-03-09  Thomas Preud'homme  <thomas.preudhomme@arm.com>

    gcc/
    PR tree-optimization/63743
    * cfgexpand.c (reorder_operands): Also reorder if only second operand
    had its definition forwarded by TER.

    gcc/testsuite/
    PR tree-optimization/63743
    * gcc.dg/pr63743.c: New test.

From-SVN: r221276

gcc/ChangeLog

+2015-03-09  Thomas Preud'homme  <thomas.preudhomme@arm.com>
+
+	PR tree-optimization/63743
+	* cfgexpand.c (reorder_operands): Also reorder if only second operand
+	had its definition forwarded by TER.
+
 2015-03-08  Jan Hubicka  <hubicka@ucw.cz>
 
 	PR lto/65316

gcc/cfgexpand.c

@@ -5124,13 +5124,11 @@ reorder_operands (basic_block bb)
 	continue;
       /* Swap operands if the second one is more expensive.  */
       def0 = get_gimple_for_ssa_name (op0);
-      if (!def0)
-	continue;
       def1 = get_gimple_for_ssa_name (op1);
       if (!def1)
 	continue;
       swap = false;
-      if (lattice[gimple_uid (def1)] > lattice[gimple_uid (def0)])
+      if (!def0 || lattice[gimple_uid (def1)] > lattice[gimple_uid (def0)])
 	swap = true;
       if (swap)
 	{
@@ -5139,7 +5137,7 @@ reorder_operands (basic_block bb)
 	      fprintf (dump_file, "Swap operands in stmt:\n");
 	      print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
 	      fprintf (dump_file, "Cost left opnd=%d, right opnd=%d\n",
-		       lattice[gimple_uid (def0)],
+		       def0 ? lattice[gimple_uid (def0)] : 0,
 		       lattice[gimple_uid (def1)]);
 	    }
 	  swap_ssa_operands (stmt, gimple_assign_rhs1_ptr (stmt),

gcc/testsuite/ChangeLog

+2015-03-09  Thomas Preud'homme  <thomas.preudhomme@arm.com>
+
+	PR tree-optimization/63743
+	* gcc.dg/pr63743.c: New test.
+
 2015-03-08  Jan Hubicka  <hubicka@ucw.cz>
 
 	PR lto/65316

gcc/testsuite/gcc.dg/pr63743.c

+/* { dg-do compile } */
+/* { dg-options "-O1 -fdump-rtl-expand-details" } */
+
+double
+libcall_dep (double x, double y)
+{
+  return x * (x + y);
+}
+
+/* { dg-final { scan-rtl-dump-times "Swap operands" 1 "expand" } } */
+/* { dg-final { cleanup-rtl-dump "expand" } } */