* tc-i386.c (i386_align_code): Implement x86_64 neutral code fillers.

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 95f4a61..86d2b3d 100644 (file)
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,7 @@
+Wed Jul 17 00:30:13 CEST 2002  Jan Hubicka  <jh@suse.cz>
+
+       * tc-i386.c (i386_align_code): Implement x86_64 neutral code fillers.
+
 2002-07-16  Moritz Jodeit  <moritz@jodeit.org>
 
        * config/tc-z8k.c (build_bytes): Correct order of memset args.

diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c
index c7dbfbd..85611de 100644 (file)
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -521,26 +521,45 @@ i386_align_code (fragP, count)
     f32_15, f32_15, f32_15, f32_15, f32_15, f32_15, f32_15
   };
 
-  /* ??? We can't use these fillers for x86_64, since they often kills the
-     upper halves.  Solve later.  */
-  if (flag_code == CODE_64BIT)
-    count = 1;
+  if (count <= 0 || count > 15)
+    return;
 
-  if (count > 0 && count <= 15)
+  /* The recommended way to pad 64bit code is to use NOPs preceded by
+     maximally four 0x66 prefixes.  Balance the size of nops.  */
+  if (flag_code == CODE_64BIT)
     {
-      if (flag_code == CODE_16BIT)
+      int i;
+      int nnops = (count + 3) / 4;
+      int len = count / nnops;
+      int remains = count - nnops * len;
+      int pos = 0;
+
+      for (i = 0; i < remains; i++)
        {
-         memcpy (fragP->fr_literal + fragP->fr_fix,
-                 f16_patt[count - 1], count);
-         if (count > 8)
-           /* Adjust jump offset.  */
-           fragP->fr_literal[fragP->fr_fix + 1] = count - 2;
+         memset (fragP->fr_literal + fragP->fr_fix + pos, 0x66, len);
+         fragP->fr_literal[fragP->fr_fix + pos + len] = 0x90;
+         pos += len + 1;
+       }
+      for (; i < nnops; i++)
+       {
+         memset (fragP->fr_literal + fragP->fr_fix + pos, 0x66, len - 1);
+         fragP->fr_literal[fragP->fr_fix + pos + len - 1] = 0x90;
+         pos += len;
        }
-      else
-       memcpy (fragP->fr_literal + fragP->fr_fix,
-               f32_patt[count - 1], count);
-      fragP->fr_var = count;
     }
+  else
+    if (flag_code == CODE_16BIT)
+      {
+       memcpy (fragP->fr_literal + fragP->fr_fix,
+               f16_patt[count - 1], count);
+       if (count > 8)
+         /* Adjust jump offset.  */
+         fragP->fr_literal[fragP->fr_fix + 1] = count - 2;
+      }
+    else
+      memcpy (fragP->fr_literal + fragP->fr_fix,
+             f32_patt[count - 1], count);
+  fragP->fr_var = count;
 }
 
 static INLINE unsigned int