re PR libfortran/48787 (Invalid UP/DOWN rounding with F editing)

2011-05-01  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

	PR libgfortran/48787
	* io/write_float.def (output_float): Gather up integer declarations and
	add new 'p' for scale factor. Use 'p' in place of the 'dtp' reference
	everywhere. For ROUND_UP scan the digit string and only perform
	rounding if something other than '0' is found.

From-SVN: r173231

diff --git a/libgfortran/ChangeLog b/libgfortran/ChangeLog
index a53f95053b1467f65cbf138858bad5d2fb7b8f13..5b73722581cad2fe4a959f51a129c9cd96d0597c 100644 (file)
--- a/libgfortran/ChangeLog
+++ b/libgfortran/ChangeLog
@@ -1,3 +1,11 @@
+2011-05-01  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
+
+       PR libgfortran/48787
+       * io/write_float.def (output_float): Gather up integer declarations and
+       add new 'p' for scale factor. Use 'p' in place of the 'dtp' reference
+       everywhere. For ROUND_UP scan the digit string and only perform
+       rounding if something other than '0' is found.
+
 2011-04-29  Janne Blomqvist  <jb@gcc.gnu.org>
 
        * io/unix.c (min): New macro.

diff --git a/libgfortran/io/write_float.def b/libgfortran/io/write_float.def
index 2e2b4d87bf478a4432e2bdd6c2c722ddcf990a01..7f3cedd10349b8ed9f8d8d7be824799e2c2820ab 100644 (file)
--- a/libgfortran/io/write_float.def
+++ b/libgfortran/io/write_float.def
@@ -67,11 +67,9 @@ output_float (st_parameter_dt *dtp, const fnode *f, char *buffer, size_t size,
 {
   char *out;
   char *digits;
-  int e;
+  int e, w, d, p, i;
   char expchar, rchar;
   format_token ft;
-  int w;
-  int d;
   /* Number of digits before the decimal point.  */
   int nbefore;
   /* Number of zeros after the decimal point.  */
@@ -82,12 +80,12 @@ output_float (st_parameter_dt *dtp, const fnode *f, char *buffer, size_t size,
   int nzero_real;
   int leadzero;
   int nblanks;
-  int i;
   sign_t sign;
 
   ft = f->format;
   w = f->u.real.w;
   d = f->u.real.d;
+  p = dtp->u.p.scale_factor;
 
   rchar = '5';
   nzero_real = -1;
@@ -119,14 +117,14 @@ output_float (st_parameter_dt *dtp, const fnode *f, char *buffer, size_t size,
   switch (ft)
     {
     case FMT_F:
-      if (d == 0 && e <= 0 && dtp->u.p.scale_factor == 0)
+      if (d == 0 && e <= 0 && p == 0)
        {
          memmove (digits + 1, digits, ndigits - 1);
          digits[0] = '0';
          e++;
        }
 
-      nbefore = e + dtp->u.p.scale_factor;
+      nbefore = e + p;
       if (nbefore < 0)
        {
          nzero = -nbefore;
@@ -147,13 +145,13 @@ output_float (st_parameter_dt *dtp, const fnode *f, char *buffer, size_t size,
     case FMT_E:
     case FMT_D:
       i = dtp->u.p.scale_factor;
-      if (d <= 0 && i == 0)
+      if (d <= 0 && p == 0)
        {
          generate_error (&dtp->common, LIBERROR_FORMAT, "Precision not "
                          "greater than zero in format specifier 'E' or 'D'");
          return FAILURE;
        }
-      if (i <= -d || i >= d + 2)
+      if (p <= -d || p >= d + 2)
        {
          generate_error (&dtp->common, LIBERROR_FORMAT, "Scale factor "
                          "out of range in format specifier 'E' or 'D'");
@@ -161,20 +159,20 @@ output_float (st_parameter_dt *dtp, const fnode *f, char *buffer, size_t size,
        }
 
       if (!zero_flag)
-       e -= i;
-      if (i < 0)
+       e -= p;
+      if (p < 0)
        {
          nbefore = 0;
-         nzero = -i;
-         nafter = d + i;
+         nzero = -p;
+         nafter = d + p;
        }
-      else if (i > 0)
+      else if (p > 0)
        {
-         nbefore = i;
+         nbefore = p;
          nzero = 0;
-         nafter = (d - i) + 1;
+         nafter = (d - p) + 1;
        }
-      else /* i == 0 */
+      else /* p == 0 */
        {
          nbefore = 0;
          nzero = 0;
@@ -233,7 +231,13 @@ output_float (st_parameter_dt *dtp, const fnode *f, char *buffer, size_t size,
        if (sign_bit)
          goto skip;
        rchar = '0';
-       break;
+       /* Scan for trailing zeros to see if we really need to round it.  */
+       for(i = nbefore + nafter; i < ndigits; i++)
+         {
+           if (digits[i] != '0')
+             goto do_rnd;
+         }
+       goto skip;
       case ROUND_DOWN:
        if (!sign_bit)
          goto skip;
@@ -290,8 +294,6 @@ output_float (st_parameter_dt *dtp, const fnode *f, char *buffer, size_t size,
   else if (nbefore + nafter < ndigits)
     {
       i = ndigits = nbefore + nafter;
-      if (d == 0 && digits[1] == '0')
-       goto skip;
       if (digits[i] >= rchar)
        {
          /* Propagate the carry.  */