re PR libfortran/59771 (Cleanup handling of Gw.0 and Gw.0Ee format)

2014-01-19  Jerry DeLisle  <jvdelisle@gcc.gnu>
	    Dominique d'Humieres  <dominiq@lps.ens.fr>

	PR libfortran/59771
	PR libfortran/59774
	PR libfortran/59836
	* io/write_float.def (output_float): Fix wrong handling of the
	Fw.0 format.
	(output_float_FMT_G_): Fixes rounding issues with -m32.

Co-Authored-By: Dominique d'Humieres <dominiq@lps.ens.fr>

From-SVN: r206785

libgfortran/ChangeLog

+2014-01-19  Jerry DeLisle  <jvdelisle@gcc.gnu>
+	    Dominique d'Humieres  <dominiq@lps.ens.fr>
+
+	PR libfortran/59771
+	PR libfortran/59774
+	PR libfortran/59836
+	* io/write_float.def (output_float): Fix wrong handling of the
+	Fw.0 format.
+	(output_float_FMT_G_): Fixes rounding issues with -m32.
+
 2014-01-11  Jerry DeLisle  <jvdelisle@gcc.gnu>
 	    Dominique d'Humieres  <dominiq@lps.ens.fr>
 	    Steven G. Kargl  <kargl@gcc.gnu.org>

libgfortran/io/write_float.def

@@ -373,7 +373,7 @@ output_float (st_parameter_dt *dtp, const fnode *f, char *buffer, size_t size,
   updown:
 
   rchar = '0';
-  if (w > 0 && d == 0 && p == 0)
+  if (ft != FMT_F && nbefore == 0 && w > 0 && d == 0 && p == 0)
     nbefore = 1;
   /* Scan for trailing zeros to see if we really need to round it.  */
   for(i = nbefore + nafter; i < ndigits; i++)
@@ -386,13 +386,14 @@ output_float (st_parameter_dt *dtp, const fnode *f, char *buffer, size_t size,
   do_rnd:
  
   if (nbefore + nafter == 0)
+    /* Handle the case Fw.0 and value < 1.0 */
     {
       ndigits = 0;
       if (nzero_real == d && digits[0] >= rchar)
 	{
 	  /* We rounded to zero but shouldn't have */
-	  nzero--;
-	  nafter = 1;
+	  nbefore = 1;
+	  digits--;
 	  digits[0] = '1';
 	  ndigits = 1;
 	}
@@ -1018,13 +1019,14 @@ output_float_FMT_G_ ## x (st_parameter_dt *dtp, const fnode *f, \
   int d = f->u.real.d;\
   int w = f->u.real.w;\
   fnode newf;\
-  GFC_REAL_ ## x rexp_d, r = 0.5;\
+  GFC_REAL_ ## x exp_d, r = 0.5, r_sc;\
   int low, high, mid;\
   int ubound, lbound;\
   char *p, pad = ' ';\
   int save_scale_factor, nb = 0;\
   bool result;\
   int nprinted, precision;\
+  volatile GFC_REAL_ ## x temp;\
 \
   save_scale_factor = dtp->u.p.scale_factor;\
 \
@@ -1043,10 +1045,13 @@ output_float_FMT_G_ ## x (st_parameter_dt *dtp, const fnode *f, \
 	break;\
     }\
 \
-  rexp_d = calculate_exp_ ## x (-d);\
-  if ((m > 0.0 && ((m < 0.1 - 0.1 * r * rexp_d) || (rexp_d * (m + r) >= 1.0)))\
+  exp_d = calculate_exp_ ## x (d);\
+  r_sc = (1 - r / exp_d);\
+  temp = 0.1 * r_sc;\
+  if ((m > 0.0 && ((m < temp) || (r >= (exp_d - m))))\
       || ((m == 0.0) && !(compile_options.allow_std\
-			  & (GFC_STD_F2003 | GFC_STD_F2008))))\
+			  & (GFC_STD_F2003 | GFC_STD_F2008)))\
+      ||  d == 0)\
     { \
       newf.format = FMT_E;\
       newf.u.real.w = w;\
@@ -1066,10 +1071,9 @@ output_float_FMT_G_ ## x (st_parameter_dt *dtp, const fnode *f, \
 \
   while (low <= high)\
     { \
-      volatile GFC_REAL_ ## x temp;\
       mid = (low + high) / 2;\
 \
-      temp = (calculate_exp_ ## x (mid - 1) * (1 - r * rexp_d));\
+      temp = (calculate_exp_ ## x (mid - 1) * r_sc);\
 \
       if (m < temp)\
         { \