x86: properly force / avoid forcing EVEX encoding

[deliverable/binutils-gdb.git] / gas / write.c

diff --git a/gas/write.c b/gas/write.c
index 690852c6ba270755cc4a6006b0d9626419350632..2d0bbe4601d3599339d6fee5c0ebad1cd79a5193 100644 (file)
--- a/gas/write.c
+++ b/gas/write.c
@@ -1,5 +1,5 @@
 /* write.c - emit .o file
-   Copyright (C) 1986-2017 Free Software Foundation, Inc.
+   Copyright (C) 1986-2018 Free Software Foundation, Inc.
 
    This file is part of GAS, the GNU Assembler.
 
@@ -435,6 +435,8 @@ cvt_frag_to_fill (segT sec ATTRIBUTE_UNUSED, fragS *fragP)
 {
   switch (fragP->fr_type)
     {
+    case rs_space_nop:
+      goto skip_align;
     case rs_align:
     case rs_align_code:
     case rs_align_test:
@@ -443,6 +445,7 @@ cvt_frag_to_fill (segT sec ATTRIBUTE_UNUSED, fragS *fragP)
 #ifdef HANDLE_ALIGN
       HANDLE_ALIGN (fragP);
 #endif
+skip_align:
       know (fragP->fr_next != NULL);
       fragP->fr_offset = (fragP->fr_next->fr_address
                          - fragP->fr_address
@@ -450,14 +453,18 @@ cvt_frag_to_fill (segT sec ATTRIBUTE_UNUSED, fragS *fragP)
       if (fragP->fr_offset < 0)
        {
          as_bad_where (fragP->fr_file, fragP->fr_line,
-                       _("attempt to .org/.space backwards? (%ld)"),
+                       _("attempt to .org/.space/.nops backwards? (%ld)"),
                        (long) fragP->fr_offset);
          fragP->fr_offset = 0;
        }
-      fragP->fr_type = rs_fill;
+      if (fragP->fr_type == rs_space_nop)
+       fragP->fr_type = rs_fill_nop;
+      else
+       fragP->fr_type = rs_fill;
       break;
 
     case rs_fill:
+    case rs_fill_nop:
       break;
 
     case rs_leb128:
@@ -919,9 +926,7 @@ fixup_segment (fixS *fixP, segT this_segment)
   /* If the linker is doing the relaxing, we must not do any fixups.
 
      Well, strictly speaking that's not true -- we could do any that
-     are PC-relative and don't cross regions that could change size.
-     And for the i960 we might be able to turn callx/callj into bal
-     anyways in cases where we know the maximum displacement.  */
+     are PC-relative and don't cross regions that could change size.  */
   if (linkrelax && TC_LINKRELAX_FIXUP (this_segment))
     {
       for (; fixP; fixP = fixP->fx_next)
@@ -1570,6 +1575,20 @@ compress_debug (bfd *abfd, asection *sec, void *xxx ATTRIBUTE_UNUSED)
     }
 }
 
+#ifndef md_generate_nops
+/* Genenerate COUNT bytes of no-op instructions to WHERE.  A target
+   backend must override this with proper no-op instructions.   */
+
+static void
+md_generate_nops (fragS *f ATTRIBUTE_UNUSED,
+                 char *where ATTRIBUTE_UNUSED,
+                 offsetT count ATTRIBUTE_UNUSED,
+                 int control ATTRIBUTE_UNUSED)
+{
+  as_bad (_("unimplemented .nops directive"));
+}
+#endif
+
 static void
 write_contents (bfd *abfd ATTRIBUTE_UNUSED,
                asection *sec,
@@ -1593,7 +1612,7 @@ write_contents (bfd *abfd ATTRIBUTE_UNUSED,
       char *fill_literal;
       offsetT count;
 
-      gas_assert (f->fr_type == rs_fill);
+      gas_assert (f->fr_type == rs_fill || f->fr_type == rs_fill_nop);
       if (f->fr_fix)
        {
          x = bfd_set_section_contents (stdoutput, sec,
@@ -1610,9 +1629,35 @@ write_contents (bfd *abfd ATTRIBUTE_UNUSED,
                      bfd_errmsg (bfd_get_error ()));
          offset += f->fr_fix;
        }
-      fill_literal = f->fr_literal + f->fr_fix;
+
       fill_size = f->fr_var;
       count = f->fr_offset;
+      fill_literal = f->fr_literal + f->fr_fix;
+
+      if (f->fr_type == rs_fill_nop)
+       {
+         gas_assert (count >= 0 && fill_size == 1);
+         if (count > 0)
+           {
+             char *buf = xmalloc (count);
+             md_generate_nops (f, buf, count, *fill_literal);
+             x = bfd_set_section_contents
+               (stdoutput, sec, buf, (file_ptr) offset,
+                (bfd_size_type) count);
+             if (!x)
+               as_fatal (ngettext ("can't fill %ld byte "
+                                   "in section %s of %s: '%s'",
+                                   "can't fill %ld bytes "
+                                   "in section %s of %s: '%s'",
+                                   (long) count), (long) count,
+                                   sec->name, stdoutput->filename,
+                                   bfd_errmsg (bfd_get_error ()));
+             offset += count;
+             free (buf);
+           }
+         continue;
+       }
+
       gas_assert (count >= 0);
       if (fill_size && count)
        {
@@ -2461,6 +2506,7 @@ relax_segment (struct frag *segment_frag_root, segT segment, int pass)
          break;
 
        case rs_space:
+       case rs_space_nop:
          break;
 
        case rs_machine_dependent:
@@ -2765,6 +2811,7 @@ relax_segment (struct frag *segment_frag_root, segT segment, int pass)
                break;
 
              case rs_space:
+             case rs_space_nop:
                growth = 0;
                if (symbolP)
                  {
@@ -2791,7 +2838,7 @@ relax_segment (struct frag *segment_frag_root, segT segment, int pass)
                          }
 
                        as_warn_where (fragP->fr_file, fragP->fr_line,
-                                      _(".space or .fill with negative value, ignored"));
+                                      _(".space, .nops or .fill with negative value, ignored"));
                        fragP->fr_symbol = 0;
                      }
                    else