2005-07-23 Jerry DeLisle <jvdelisle@verizon.net>

    * io/write.c (write_float): Revise output of IEEE exceptional
    values to comply with F95 and F2003 standards.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@102324 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 34 insertions, 4 deletions

diff --git a/libgfortran/io/write.c b/libgfortran/io/write.c
index 54bf480fdf3..a702de18a2a 100644
--- a/libgfortran/io/write.c
+++ b/libgfortran/io/write.c
@@ -772,6 +772,11 @@ write_float (fnode *f, const char *source, int len)
       if (res == 0)
 	{
 	  nb =  f->u.real.w;
+	  
+	  /* If the field width is zero, the processor must select a width 
+	     not zero.  4 is chosen to allow output of '-Inf' or '+Inf' */
+	     
+	  if (nb == 0) nb = 4;
 	  p = write_block (nb);
 	  if (nb < 3)
 	    {
@@ -784,18 +789,43 @@ write_float (fnode *f, const char *source, int len)
 	  if (res != 0)
 	    {
 	      if (signbit(n))
-		fin = '-';
+	        {
+	        
+	          /* If the sign is negative and the width is 3, there is
+	             insufficient room to output '-Inf', so output asterisks */
+	             
+	          if (nb == 3)
+	            {
+	              memset (p, '*',nb);
+	              return;
+	            }
+	            
+	          /* The negative sign is mandatory */
+	            
+	          fin = '-';
+		}    
 	      else
-		fin = '+';
+	      
+	          /* The positive sign is optional, but we output it for
+	             consistency */
+	             
+		  fin = '+';
 
 	      if (nb > 8)
+	      
+	        /* We have room, so output 'Infinity' */
+	        
 		memcpy(p + nb - 8, "Infinity", 8);
 	      else
+	      
+	        /* For the case of width equals 8, there is not enough room
+	           for the sign and 'Infinity' so we go with 'Inf' */
+	            
 		memcpy(p + nb - 3, "Inf", 3);
 	      if (nb < 9 && nb > 3)
-		p[nb - 4] = fin;
+		p[nb - 4] = fin;  /* Put the sign in front of Inf */
 	      else if (nb > 8)
-		p[nb - 9] = fin;
+		p[nb - 9] = fin;  /* Put the sign in front of Infinity */
 	    }
 	  else
 	    memcpy(p + nb - 3, "NaN", 3);