diff --git a/gcc/config/rs6000/rs6000-gen-builtins.c b/gcc/config/rs6000/rs6000-gen-builtins.c
index 18922d829ff..6f393ee46d3 100644
--- a/gcc/config/rs6000/rs6000-gen-builtins.c
+++ b/gcc/config/rs6000/rs6000-gen-builtins.c
@@ -1988,10 +1988,237 @@ parse_ovld (void)
   return result;
 }
 
+/* Write a comment at the top of FILE about how the code was generated.  */
+static void
+write_autogenerated_header (FILE *file)
+{
+  fprintf (file, "/* Automatically generated by the program '%s'\n",
+	   pgm_path);
+  fprintf (file, "   from the files '%s' and '%s'.  */\n\n",
+	   bif_path, ovld_path);
+}
+
+/* Write declarations into the header file.  */
+static void
+write_decls (void)
+{
+  fprintf (header_file, "enum rs6000_gen_builtins\n{\n  RS6000_BIF_NONE,\n");
+  for (int i = 0; i <= curr_bif; i++)
+    fprintf (header_file, "  RS6000_BIF_%s,\n", bifs[bif_order[i]].idname);
+  fprintf (header_file, "  RS6000_BIF_MAX,\n");
+  fprintf (header_file, "  RS6000_OVLD_NONE,\n");
+  for (int i = 0; i < num_ovld_stanzas; i++)
+    fprintf (header_file, "  RS6000_OVLD_%s,\n", ovld_stanzas[i].stanza_id);
+  fprintf (header_file, "  RS6000_OVLD_MAX\n};\n\n");
+
+  fprintf (header_file,
+	   "extern GTY(()) tree rs6000_builtin_decls_x[RS6000_OVLD_MAX];\n\n");
+
+  fprintf (header_file,
+	   "enum rs6000_ovld_instances\n{\n  RS6000_INST_NONE,\n");
+  for (int i = 0; i <= curr_ovld; i++)
+    fprintf (header_file, "  RS6000_INST_%s,\n", ovlds[i].ovld_id_name);
+  fprintf (header_file, "  RS6000_INST_MAX\n};\n\n");
+
+  fprintf (header_file, "#define MAX_OVLD_ARGS %d\n", max_ovld_args);
+
+  fprintf (header_file, "enum restriction {\n");
+  fprintf (header_file, "  RES_NONE,\n");
+  fprintf (header_file, "  RES_BITS,\n");
+  fprintf (header_file, "  RES_RANGE,\n");
+  fprintf (header_file, "  RES_VAR_RANGE,\n");
+  fprintf (header_file, "  RES_VALUES\n");
+  fprintf (header_file, "};\n\n");
+
+  fprintf (header_file, "enum bif_enable {\n");
+  fprintf (header_file, "  ENB_ALWAYS,\n");
+  fprintf (header_file, "  ENB_P5,\n");
+  fprintf (header_file, "  ENB_P6,\n");
+  fprintf (header_file, "  ENB_ALTIVEC,\n");
+  fprintf (header_file, "  ENB_CELL,\n");
+  fprintf (header_file, "  ENB_VSX,\n");
+  fprintf (header_file, "  ENB_P7,\n");
+  fprintf (header_file, "  ENB_P7_64,\n");
+  fprintf (header_file, "  ENB_P8,\n");
+  fprintf (header_file, "  ENB_P8V,\n");
+  fprintf (header_file, "  ENB_P9,\n");
+  fprintf (header_file, "  ENB_P9_64,\n");
+  fprintf (header_file, "  ENB_P9V,\n");
+  fprintf (header_file, "  ENB_IEEE128_HW,\n");
+  fprintf (header_file, "  ENB_DFP,\n");
+  fprintf (header_file, "  ENB_CRYPTO,\n");
+  fprintf (header_file, "  ENB_HTM,\n");
+  fprintf (header_file, "  ENB_P10,\n");
+  fprintf (header_file, "  ENB_P10_64,\n");
+  fprintf (header_file, "  ENB_MMA\n");
+  fprintf (header_file, "};\n\n");
+
+  fprintf (header_file, "#define PPC_MAXRESTROPNDS 3\n");
+  fprintf (header_file, "struct GTY((user)) bifdata\n");
+  fprintf (header_file, "{\n");
+  fprintf (header_file, "  const char *bifname;\n");
+  fprintf (header_file, "  bif_enable enable;\n");
+  fprintf (header_file, "  tree fntype;\n");
+  fprintf (header_file, "  insn_code icode;\n");
+  fprintf (header_file, "  int  nargs;\n");
+  fprintf (header_file, "  int  bifattrs;\n");
+  fprintf (header_file, "  int  restr_opnd[PPC_MAXRESTROPNDS];\n");
+  fprintf (header_file, "  restriction restr[PPC_MAXRESTROPNDS];\n");
+  fprintf (header_file, "  int  restr_val1[PPC_MAXRESTROPNDS];\n");
+  fprintf (header_file, "  int  restr_val2[PPC_MAXRESTROPNDS];\n");
+  fprintf (header_file, "  const char *attr_string;\n");
+  fprintf (header_file, "  rs6000_gen_builtins assoc_bif;\n");
+  fprintf (header_file, "};\n\n");
+
+  fprintf (header_file, "#define bif_init_bit\t\t(0x00000001)\n");
+  fprintf (header_file, "#define bif_set_bit\t\t(0x00000002)\n");
+  fprintf (header_file, "#define bif_extract_bit\t\t(0x00000004)\n");
+  fprintf (header_file, "#define bif_nosoft_bit\t\t(0x00000008)\n");
+  fprintf (header_file, "#define bif_ldvec_bit\t\t(0x00000010)\n");
+  fprintf (header_file, "#define bif_stvec_bit\t\t(0x00000020)\n");
+  fprintf (header_file, "#define bif_reve_bit\t\t(0x00000040)\n");
+  fprintf (header_file, "#define bif_pred_bit\t\t(0x00000080)\n");
+  fprintf (header_file, "#define bif_htm_bit\t\t(0x00000100)\n");
+  fprintf (header_file, "#define bif_htmspr_bit\t\t(0x00000200)\n");
+  fprintf (header_file, "#define bif_htmcr_bit\t\t(0x00000400)\n");
+  fprintf (header_file, "#define bif_mma_bit\t\t(0x00000800)\n");
+  fprintf (header_file, "#define bif_quad_bit\t\t(0x00001000)\n");
+  fprintf (header_file, "#define bif_pair_bit\t\t(0x00002000)\n");
+  fprintf (header_file, "#define bif_no32bit_bit\t\t(0x00004000)\n");
+  fprintf (header_file, "#define bif_32bit_bit\t\t(0x00008000)\n");
+  fprintf (header_file, "#define bif_cpu_bit\t\t(0x00010000)\n");
+  fprintf (header_file, "#define bif_ldstmask_bit\t(0x00020000)\n");
+  fprintf (header_file, "#define bif_lxvrse_bit\t\t(0x00040000)\n");
+  fprintf (header_file, "#define bif_lxvrze_bit\t\t(0x00080000)\n");
+  fprintf (header_file, "#define bif_endian_bit\t\t(0x00100000)\n");
+  fprintf (header_file, "\n");
+  fprintf (header_file,
+	   "#define bif_is_init(x)\t\t((x).bifattrs & bif_init_bit)\n");
+  fprintf (header_file,
+	   "#define bif_is_set(x)\t\t((x).bifattrs & bif_set_bit)\n");
+  fprintf (header_file,
+	   "#define bif_is_extract(x)\t((x).bifattrs & bif_extract_bit)\n");
+  fprintf (header_file,
+	   "#define bif_is_nosoft(x)\t((x).bifattrs & bif_nosoft_bit)\n");
+  fprintf (header_file,
+	   "#define bif_is_ldvec(x)\t\t((x).bifattrs & bif_ldvec_bit)\n");
+  fprintf (header_file,
+	   "#define bif_is_stvec(x)\t\t((x).bifattrs & bif_stvec_bit)\n");
+  fprintf (header_file,
+	   "#define bif_is_reve(x)\t\t((x).bifattrs & bif_reve_bit)\n");
+  fprintf (header_file,
+	   "#define bif_is_predicate(x)\t((x).bifattrs & bif_pred_bit)\n");
+  fprintf (header_file,
+	   "#define bif_is_htm(x)\t\t((x).bifattrs & bif_htm_bit)\n");
+  fprintf (header_file,
+	   "#define bif_is_htmspr(x)\t((x).bifattrs & bif_htmspr_bit)\n");
+  fprintf (header_file,
+	   "#define bif_is_htmcr(x)\t\t((x).bifattrs & bif_htmcr_bit)\n");
+  fprintf (header_file,
+	   "#define bif_is_mma(x)\t\t((x).bifattrs & bif_mma_bit)\n");
+  fprintf (header_file,
+	   "#define bif_is_quad(x)\t\t((x).bifattrs & bif_quad_bit)\n");
+  fprintf (header_file,
+	   "#define bif_is_pair(x)\t\t((x).bifattrs & bif_pair_bit)\n");
+  fprintf (header_file,
+	   "#define bif_is_no32bit(x)\t((x).bifattrs & bif_no32bit_bit)\n");
+  fprintf (header_file,
+	   "#define bif_is_32bit(x)\t((x).bifattrs & bif_32bit_bit)\n");
+  fprintf (header_file,
+	   "#define bif_is_cpu(x)\t\t((x).bifattrs & bif_cpu_bit)\n");
+  fprintf (header_file,
+	   "#define bif_is_ldstmask(x)\t((x).bifattrs & bif_ldstmask_bit)\n");
+  fprintf (header_file,
+	   "#define bif_is_lxvrse(x)\t((x).bifattrs & bif_lxvrse_bit)\n");
+  fprintf (header_file,
+	   "#define bif_is_lxvrze(x)\t((x).bifattrs & bif_lxvrze_bit)\n");
+  fprintf (header_file,
+	   "#define bif_is_endian(x)\t((x).bifattrs & bif_endian_bit)\n");
+  fprintf (header_file, "\n");
+
+  /* #### Note that the _x is added for now to avoid conflict with
+     the existing rs6000_builtin_info[] file while testing.  It will
+     be removed as we progress.  */
+  /* #### Cannot mark this as a GC root because only pointer types can
+     be marked as GTY((user)) and be GC roots.  All trees in here are
+     kept alive by other globals, so not a big deal.  Alternatively,
+     we could change the enum fields to ints and cast them in and out
+     to avoid requiring a GTY((user)) designation, but that seems
+     unnecessarily gross.  */
+  fprintf (header_file,
+	   "extern bifdata rs6000_builtin_info_x[RS6000_BIF_MAX];\n\n");
+
+  fprintf (header_file, "struct GTY((user)) ovlddata\n");
+  fprintf (header_file, "{\n");
+  fprintf (header_file, "  const char *bifname;\n");
+  fprintf (header_file, "  rs6000_gen_builtins bifid;\n");
+  fprintf (header_file, "  tree fntype;\n");
+  fprintf (header_file, "  ovlddata *next;\n");
+  fprintf (header_file, "};\n\n");
+
+  fprintf (header_file, "struct ovldrecord\n");
+  fprintf (header_file, "{\n");
+  fprintf (header_file, "  const char *ovld_name;\n");
+  fprintf (header_file, "  ovlddata *first_instance;\n");
+  fprintf (header_file, "};\n\n");
+
+  /* #### Cannot mark this as a GC root because only pointer types can
+     be marked as GTY((user)) and be GC roots.  All trees in here are
+     kept alive by other globals, so not a big deal.  Alternatively,
+     we could change the enum fields to ints and cast them in and out
+     to avoid requiring a GTY((user)) designation, but that seems
+     unnecessarily gross.  */
+  fprintf (header_file,
+	   "extern ovlddata rs6000_instance_info[RS6000_INST_MAX];\n");
+  fprintf (header_file, "extern ovldrecord rs6000_overload_info[];\n\n");
+
+  fprintf (header_file, "extern void rs6000_autoinit_builtins ();\n\n");
+  fprintf (header_file,
+	   "extern bool rs6000_new_builtin_is_supported_p "
+	   "(rs6000_gen_builtins);\n");
+  fprintf (header_file,
+	   "extern tree rs6000_builtin_decl (unsigned, "
+	   "bool ATTRIBUTE_UNUSED);\n\n");
+  fprintf (header_file,
+	   "extern void gt_ggc_mx (bifdata *bd);\n");
+  fprintf (header_file,
+	   "extern void gt_pch_nx (bifdata *bd);\n");
+  fprintf (header_file,
+	   "extern void gt_pch_nx (bifdata *bd, gt_pointer_operator op, "
+	   "void *cookie);\n");
+  fprintf (header_file,
+	   "extern void gt_ggc_mx (ovlddata *od);\n");
+  fprintf (header_file,
+	   "extern void gt_pch_nx (ovlddata *od);\n");
+  fprintf (header_file,
+	   "extern void gt_pch_nx (ovlddata *od, gt_pointer_operator op, "
+	   "void *cookie);\n");
+}
+
+/* Callback functions used for generating trees for function types.  */
+void
+write_extern_fntype (char *str)
+{
+  fprintf (header_file, "extern GTY(()) tree %s;\n", str);
+}
+
 /* Write everything to the header file (rs6000-builtins.h).  */
 static int
 write_header_file (void)
 {
+  write_autogenerated_header (header_file);
+
+  fprintf (header_file, "#ifndef _RS6000_BUILTINS_H\n");
+  fprintf (header_file, "#define _RS6000_BUILTINS_H 1\n\n");
+  fprintf (header_file, "extern int new_builtins_are_live;\n\n");
+
+  write_decls ();
+
+  /* Write function type list declarators to the header file.  */
+  rbt_inorder_callback (&fntype_rbt, fntype_rbt.rbt_root, write_extern_fntype);
+  fprintf (header_file, "\n");
+  fprintf (header_file, "\n#endif\n");
+
   return 1;
 }
 
