Add support to the Xtensa target for creating trampolines for out-of-range branches.

    * tc-xtensa.c (xtensa_check_frag_count, xtensa_create_trampoline_frag)
    (xtensa_maybe_create_trampoline_frag, init_trampoline_frag)
    (find_trampoline_seg, search_trampolines, get_best_trampoline)
    (check_and_update_trampolines, add_jump_to_trampoline)
    (dump_trampolines): New function.
    (md_parse_option): Add cases for --[no-]trampolines options.
    (md_assemble, finish_vinsn, xtensa_end): Add call to
    xtensa_check_frag_count.
    (xg_assemble_vliw_tokens): Add call to
    xtensa_maybe_create_trampoline_frag.
    (xtensa_relax_frag): Relax fragments with RELAX_TRAMPOLINE state.
    (relax_frag_immed): Relax jump instructions that cannot reach its
    target.
    * tc-xtensa.h (xtensa_relax_statesE::RELAX_TRAMPOLINE): New relax
    state.

    * as.texinfo: Document --[no-]trampolines command-line options.
    * c-xtensa.texi: Document trampolines relaxation and command line
    options.

    * frags.c (get_frag_count, clear_frag_count): New function.
    (frag_alloc): Increment totalfrags counter.
    * frags.h (get_frag_count, clear_frag_count): New function.

    * all.exp: Add test for trampoline relaxation.
    * trampoline.d: Trampoline relaxation expected dump.
    * trampoline.s: Trampoline relaxation test source.

1 files changed, 5 insertions, 0 deletions

diff --git a/gas/config/tc-xtensa.h b/gas/config/tc-xtensa.h
index 0bf1240..4672bc6 100644
--- a/gas/config/tc-xtensa.h
+++ b/gas/config/tc-xtensa.h
@@ -180,6 +180,11 @@ enum xtensa_relax_statesE
      prevent the linker from changing the size of any frag between the
      section start and the org frag.  */
 
+  RELAX_TRAMPOLINE,
+  /* Every few thousand frags, we insert one of these, just in case we may
+     need some space for a trampoline (jump to a jump) because the function
+     has gotten too big. If not needed, it disappears. */
+
   RELAX_NONE
 };