[PATCH] Fix PR47892

[PATCH] Fix PR47892

[Richard Guenther]

This fixes PR47892, we are failing to if-convert function calls,
even those we can vectorize.  This includes pow() which we
canonicalize x*x to with -ffast-math (yeah, I know ...).
No reason to not if-convert at least const builtins.

Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.

Richard.

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.

Index: gcc/tree-if-conv.c
===================================================================
*** gcc/tree-if-conv.c	(revision 172759)
--- gcc/tree-if-conv.c	(working copy)
*************** if_convertible_stmt_p (gimple stmt, VEC
*** 719,724 ****
--- 719,740 ----
      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))
Index: gcc/testsuite/gcc.dg/vect/fast-math-ifcvt-1.c
===================================================================
*** gcc/testsuite/gcc.dg/vect/fast-math-ifcvt-1.c	(revision 0)
--- gcc/testsuite/gcc.dg/vect/fast-math-ifcvt-1.c	(revision 0)
***************
*** 0 ****
--- 1,18 ----
+ /* 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" } } */