re PR c/47892 (Fails to vectorize comparison code, if-conversion fails)

2011-04-20  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/47892
	* tree-if-conv.c (if_convertible_stmt_p): Const builtins
	are if-convertible.

	* gcc.dg/vect/fast-math-ifcvt-1.c: New testcase.

From-SVN: r172774

gcc/ChangeLog

+2011-04-20  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/47892
+	* tree-if-conv.c (if_convertible_stmt_p): Const builtins
+	are if-convertible.
+
 2011-04-20  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* config/alpha/vms.h (ASM_OUTPUT_ADDR_DIFF_ELT): Do not redefine.

gcc/testsuite/ChangeLog

 2011-04-20  Richard Guenther  <rguenther@suse.de>
 
+	PR tree-optimization/47892
+	* gcc.dg/vect/fast-math-ifcvt-1.c: New testcase.
+
+2011-04-20  Richard Guenther  <rguenther@suse.de>
+
 	PR middle-end/48695
 	* g++.dg/torture/pr48695.C: New testcase.
 

gcc/testsuite/gcc.dg/vect/fast-math-ifcvt-1.c

+/* PR 47892 */
+/* { dg-do compile } */
+/* { dg-require-effective-target vect_float } */
+/* { dg-require-effective-target vect_condition } */
+
+void
+bestseries9 (float * __restrict__ arr, int len)
+{
+  int i;
+  for (i = 0; i < len; ++i)
+    {
+      float or = arr[i];
+      arr[i] = (or > 0.0f) * (2 - or * or);
+    }
+}
+
+/* { dg-final { scan-tree-dump "vectorized 1 loops" "vect" } } */
+/* { dg-final { cleanup-tree-dump "vect" } } */

gcc/tree-if-conv.c

@@ -719,6 +719,22 @@ if_convertible_stmt_p (gimple stmt, VEC (data_reference_p, heap) *refs)
     case GIMPLE_ASSIGN:
       return if_convertible_gimple_assign_stmt_p (stmt, refs);
 
+    case GIMPLE_CALL:
+      {
+	tree fndecl = gimple_call_fndecl (stmt);
+	if (fndecl)
+	  {
+	    int flags = gimple_call_flags (stmt);
+	    if ((flags & ECF_CONST)
+		&& !(flags & ECF_LOOPING_CONST_OR_PURE)
+		/* We can only vectorize some builtins at the moment,
+		   so restrict if-conversion to those.  */
+		&& DECL_BUILT_IN (fndecl))
+	      return true;
+	  }
+	return false;
+      }
+
     default:
       /* Don't know what to do with 'em so don't do anything.  */
       if (dump_file && (dump_flags & TDF_DETAILS))