Stephen L Moshier <moshier@mediaone.net>

        * real.h (MAX_LONG_DOUBLE_TYPE_SIZE): Comment.
        * real.c (toe64): Revert previous change.

From-SVN: r33097

gcc/ChangeLog

+2000-04-12  Stephen L Moshier  <moshier@mediaone.net>
+
+	* real.h (MAX_LONG_DOUBLE_TYPE_SIZE): Comment.
+	* real.c (toe64): Revert previous change.
+
 2000-04-12  Jakub Jelinek  <jakub@redhat.com>
 
 	* objc/objc-act.c: Include ggc.h.

gcc/real.c

@@ -3646,9 +3646,13 @@ toe64 (a, b)
   else
     {
       q = b + 4;			/* point to output exponent */
-#if MAX_LONG_DOUBLE_TYPE_SIZE == 96
-      /* Clear the last two bytes of 12-byte Intel format */
-      *(q+1) = 0;
+      /* The purpose of this conditional is to avoid scribbling beyond
+         the end of a long double, in case the type is only 80 bits wide.  */
+      if (LONG_DOUBLE_TYPE_SIZE == 96)
+	{
+	  /* Clear the last two bytes of 12-byte Intel format */
+	  *(q+1) = 0;
+	}
 #endif
     }
 #endif

gcc/real.h

@@ -68,6 +68,11 @@ Boston, MA 02111-1307, USA.  */
 #ifndef LONG_DOUBLE_TYPE_SIZE
 #define LONG_DOUBLE_TYPE_SIZE 64
 #endif
+/* MAX_LONG_DOUBLE_TYPE_SIZE is a constant tested by #if.
+   LONG_DOUBLE_TYPE_SIZE can vary at compiler run time.
+   So long as macros like REAL_VALUE_TO_TARGET_LONG_DOUBLE cannot
+   vary too, however, then XFmode and TFmode long double
+   cannot both be supported at the same time.  */
 #ifndef MAX_LONG_DOUBLE_TYPE_SIZE
 #define MAX_LONG_DOUBLE_TYPE_SIZE LONG_DOUBLE_TYPE_SIZE
 #endif