re PR debug/48928 (ICE: in decimal_to_decnumber, at dfp.c:113 with -O -g and decimal float)

	PR debug/48928
	* dfp.c (decimal_to_decnumber): Handle conversion from
	dconst{1,2,m1,half}.

	* gcc.dg/dfp/pr48928.c: New test.

From-SVN: r173606

gcc/ChangeLog

+2011-05-10  Jakub Jelinek  <jakub@redhat.com>
+
+	PR debug/48928
+	* dfp.c (decimal_to_decnumber): Handle conversion from
+	dconst{1,2,m1,half}.
+
 2011-05-09  Uros Bizjak  <ubizjak@gmail.com>
 
 	* config/i386/i386.c (ix86_autovectorize_vector_sizes): Return 0

gcc/dfp.c

 /* Decimal floating point support.
-   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Free Software
-   Foundation, Inc.
+   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011
+   Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -110,7 +110,33 @@ decimal_to_decnumber (const REAL_VALUE_TYPE *r, decNumber *dn)
         decNumberFromString (dn, "nan", &set);
       break;
     case rvc_normal:
-      gcc_assert (r->decimal);
+      if (!r->decimal)
+	{
+	  /* dconst{1,2,m1,half} are used in various places in
+	     the middle-end and optimizers, allow them here
+	     as an exception by converting them to decimal.  */
+	  if (memcmp (r, &dconst1, sizeof (*r)) == 0)
+	    {
+	      decNumberFromString (dn, "1", &set);
+	      break;
+	    }
+	  if (memcmp (r, &dconst2, sizeof (*r)) == 0)
+	    {
+	      decNumberFromString (dn, "2", &set);
+	      break;
+	    }
+	  if (memcmp (r, &dconstm1, sizeof (*r)) == 0)
+	    {
+	      decNumberFromString (dn, "-1", &set);
+	      break;
+	    }
+	  if (memcmp (r, &dconsthalf, sizeof (*r)) == 0)
+	    {
+	      decNumberFromString (dn, "0.5", &set);
+	      break;
+	    }
+	  gcc_unreachable ();
+	}
       decimal128ToNumber ((const decimal128 *) r->sig, dn);
       break;
     default:

gcc/testsuite/ChangeLog

+2011-05-10  Jakub Jelinek  <jakub@redhat.com>
+
+	PR debug/48928
+	* gcc.dg/dfp/pr48928.c: New test.
+
 2011-05-09  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/48522

gcc/testsuite/gcc.dg/dfp/pr48928.c

+/* PR debug/48928 */
+/* { dg-do compile } */
+/* { dg-options "-g -O2" } */
+
+_Decimal32
+foo (_Decimal32 x)
+{
+  _Decimal32 y = (x + x) / (9.DF * x);
+  return y;
+}