--- /dev/null
+From a82c7d9030b67a6a76a5403d0e1641f9e42141ac Mon Sep 17 00:00:00 2001
+From: David Weatherford <weath@cadence.com>
+Date: Fri, 21 Mar 2014 11:53:42 +0000
+Subject: [PATCH] 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.
+---
+Backported from: a82c7d9030b67a6a76a5403d0e1641f9e42141ac
+Changes to Changelog files are dropped.
+
+ gas/config/tc-xtensa.c | 558 +++++++++++++++++++++++++++++++++-
+ gas/config/tc-xtensa.h | 5 +
+ gas/frags.c | 15 +
+ gas/frags.h | 3 +
+ gas/testsuite/gas/xtensa/all.exp | 1 +
+ gas/testsuite/gas/xtensa/trampoline.d | 26 ++
+ gas/testsuite/gas/xtensa/trampoline.s | 21 ++
+ 11 files changed, 753 insertions(+), 2 deletions(-)
+ create mode 100644 gas/testsuite/gas/xtensa/trampoline.d
+ create mode 100644 gas/testsuite/gas/xtensa/trampoline.s
+
+diff --git a/gas/config/tc-xtensa.c b/gas/config/tc-xtensa.c
+index fe8ec0f..ea23c96 100644
+--- a/gas/config/tc-xtensa.c
++++ b/gas/config/tc-xtensa.c
+@@ -468,6 +468,12 @@ static void xtensa_set_frag_assembly_state (fragS *);
+ static void finish_vinsn (vliw_insn *);
+ static bfd_boolean emit_single_op (TInsn *);
+ static int total_frag_text_expansion (fragS *);
++static bfd_boolean use_trampolines = TRUE;
++static void xtensa_check_frag_count (void);
++static void xtensa_create_trampoline_frag (bfd_boolean);
++static void xtensa_maybe_create_trampoline_frag (void);
++struct trampoline_frag;
++static int init_trampoline_frag (struct trampoline_frag *);
+
+ /* Alignment Functions. */
+
+@@ -520,6 +526,7 @@ static void tinsn_from_chars (TInsn *, char *, int);
+ static void tinsn_immed_from_frag (TInsn *, fragS *, int);
+ static int get_num_stack_text_bytes (IStack *);
+ static int get_num_stack_literal_bytes (IStack *);
++static bfd_boolean tinsn_to_slotbuf (xtensa_format, int, TInsn *, xtensa_insnbuf);
+
+ /* vliw_insn functions. */
+
+@@ -687,7 +694,10 @@ enum
+ option_prefer_l32r,
+ option_prefer_const16,
+
+- option_target_hardware
++ option_target_hardware,
++
++ option_trampolines,
++ option_no_trampolines,
+ };
+
+ const char *md_shortopts = "";
+@@ -760,6 +770,9 @@ struct option md_longopts[] =
+
+ { "target-hardware", required_argument, NULL, option_target_hardware },
+
++ { "trampolines", no_argument, NULL, option_trampolines },
++ { "no-trampolines", no_argument, NULL, option_no_trampolines },
++
+ { NULL, no_argument, NULL, 0 }
+ };
+
+@@ -940,6 +953,14 @@ md_parse_option (int c, char *arg)
+ directive_state[directive_transform] = FALSE;
+ return 1;
+
++ case option_trampolines:
++ use_trampolines = TRUE;
++ return 1;
++
++ case option_no_trampolines:
++ use_trampolines = FALSE;
++ return 1;
++
+ default:
+ return 0;
+ }
+@@ -963,7 +984,9 @@ Xtensa options:\n\
+ flix bundles\n\
+ --no-allow-flix neither allow hand-written nor generate\n\
+ flix bundles\n\
+- --rename-section old=new Rename section 'old' to 'new'\n", stream);
++ --rename-section old=new Rename section 'old' to 'new'\n\
++ --[no-]trampolines [Do not] generate trampolines (jumps to jumps)\n\
++ when jumps do not reach their targets\n", stream);
+ }
+
+ \f
+@@ -5568,6 +5591,8 @@ md_assemble (char *str)
+
+ /* We've just emitted a new instruction so clear the list of labels. */
+ xtensa_clear_insn_labels ();
++
++ xtensa_check_frag_count ();
+ }
+
+
+@@ -6372,6 +6397,8 @@ finish_vinsn (vliw_insn *vinsn)
+ xg_assemble_vliw_tokens (vinsn);
+
+ xg_clear_vinsn (vinsn);
++
++ xtensa_check_frag_count ();
+ }
+
+
+@@ -7140,6 +7167,7 @@ xg_assemble_vliw_tokens (vliw_insn *vinsn)
+ RELAX_UNREACHABLE,
+ frag_now->fr_symbol, frag_now->fr_offset, NULL);
+ xtensa_set_frag_assembly_state (frag_now);
++ xtensa_maybe_create_trampoline_frag ();
+ }
+ else if (is_branch && do_align_targets ())
+ {
+@@ -7222,9 +7250,164 @@ xtensa_end (void)
+ xtensa_sanity_check ();
+
+ xtensa_add_config_info ();
++
++ xtensa_check_frag_count ();
++}
++
++
++struct trampoline_frag
++{
++ struct trampoline_frag *next;
++ bfd_boolean needs_jump_around;
++ fragS *fragP;
++ fixS *fixP;
++};
++
++struct trampoline_seg
++{
++ struct trampoline_seg *next;
++ asection *seg;
++ struct trampoline_frag trampoline_list;
++};
++
++static struct trampoline_seg trampoline_seg_list;
++#define J_RANGE (128 * 1024)
++
++static int unreachable_count = 0;
++
++
++static void
++xtensa_maybe_create_trampoline_frag (void)
++{
++ if (!use_trampolines)
++ return;
++
++ /* We create an area for possible trampolines every 10 unreachable frags.
++ These are preferred over the ones not preceded by an unreachable frag,
++ because we don't have to jump around them. This function is called after
++ each RELAX_UNREACHABLE frag is created. */
++
++ if (++unreachable_count > 10)
++ {
++ xtensa_create_trampoline_frag (FALSE);
++ clear_frag_count ();
++ unreachable_count = 0;
++ }
++}
++
++static void
++xtensa_check_frag_count (void)
++{
++ if (!use_trampolines || frag_now->tc_frag_data.is_no_transform)
++ return;
++
++ /* We create an area for possible trampolines every 8000 frags or so. This
++ is an estimate based on the max range of a "j" insn (+/-128K) divided
++ by a typical frag byte count (16), minus a few for safety. This function
++ is called after each source line is processed. */
++
++ if (get_frag_count () > 8000)
++ {
++ xtensa_create_trampoline_frag (TRUE);
++ clear_frag_count ();
++ unreachable_count = 0;
++ }
++}
++
++static xtensa_insnbuf trampoline_buf = NULL;
++static xtensa_insnbuf trampoline_slotbuf = NULL;
++
++#define TRAMPOLINE_FRAG_SIZE 3000
++
++static void
++xtensa_create_trampoline_frag (bfd_boolean needs_jump_around)
++{
++ /* Emit a frag where we can place intermediate jump instructions,
++ in case we need to jump farther than 128K bytes.
++ Each jump instruction takes three bytes.
++ We allocate enough for 1000 trampolines in each frag.
++ If that's not enough, oh well. */
++
++ struct trampoline_seg *ts = trampoline_seg_list.next;
++ struct trampoline_frag *tf;
++ char *varP;
++ fragS *fragP;
++ int size = TRAMPOLINE_FRAG_SIZE;
++
++ for ( ; ts; ts = ts->next)
++ {
++ if (ts->seg == now_seg)
++ break;
++ }
++
++ if (ts == NULL)
++ {
++ ts = (struct trampoline_seg *)xcalloc(sizeof (struct trampoline_seg), 1);
++ ts->next = trampoline_seg_list.next;
++ trampoline_seg_list.next = ts;
++ ts->seg = now_seg;
++ }
++
++ frag_wane (frag_now);
++ frag_new (0);
++ xtensa_set_frag_assembly_state (frag_now);
++ varP = frag_var (rs_machine_dependent, size, size, RELAX_TRAMPOLINE, NULL, 0, NULL);
++ fragP = (fragS *)(varP - SIZEOF_STRUCT_FRAG);
++ if (trampoline_buf == NULL)
++ {
++ trampoline_buf = xtensa_insnbuf_alloc (xtensa_default_isa);
++ trampoline_slotbuf = xtensa_insnbuf_alloc (xtensa_default_isa);
++ }
++ tf = (struct trampoline_frag *)xmalloc(sizeof (struct trampoline_frag));
++ tf->next = ts->trampoline_list.next;
++ ts->trampoline_list.next = tf;
++ tf->needs_jump_around = needs_jump_around;
++ tf->fragP = fragP;
++ tf->fixP = NULL;
++}
++
++
++static struct trampoline_seg *
++find_trampoline_seg (asection *seg)
++{
++ struct trampoline_seg *ts = trampoline_seg_list.next;
++
++ for ( ; ts; ts = ts->next)
++ {
++ if (ts->seg == seg)
++ return ts;
++ }
++
++ return NULL;
+ }
+
+
++void dump_trampolines (void);
++
++void
++dump_trampolines (void)
++{
++ struct trampoline_seg *ts = trampoline_seg_list.next;
++
++ for ( ; ts; ts = ts->next)
++ {
++ asection *seg = ts->seg;
++
++ if (seg == NULL)
++ continue;
++ fprintf(stderr, "SECTION %s\n", seg->name);
++ struct trampoline_frag *tf = ts->trampoline_list.next;
++ for ( ; tf; tf = tf->next)
++ {
++ if (tf->fragP == NULL)
++ continue;
++ fprintf(stderr, " 0x%08x: fix=%d, jump_around=%s\n",
++ (int)tf->fragP->fr_address, (int)tf->fragP->fr_fix,
++ tf->needs_jump_around ? "T" : "F");
++ }
++ }
++}
++
+ static void
+ xtensa_cleanup_align_frags (void)
+ {
+@@ -8708,6 +8891,149 @@ xtensa_relax_frag (fragS *fragP, long stretch, int *stretched_p)
+ new_stretch += relax_frag_for_align (fragP, stretch);
+ break;
+
++ case RELAX_TRAMPOLINE:
++ if (fragP->tc_frag_data.relax_seen)
++ {
++ segment_info_type *seginfo = seg_info (now_seg);
++ fragS *fP; /* The out-of-range jump. */
++ fixS *fixP;
++
++ /* Scan for jumps that will not reach. */
++ for (fixP = seginfo->fix_root; fixP ; fixP = fixP->fx_next)
++ {
++ symbolS *s = fixP->fx_addsy;
++ xtensa_opcode opcode;
++ int target;
++ int addr;
++ int delta;
++
++ if (fixP->fx_r_type < BFD_RELOC_XTENSA_SLOT0_OP ||
++ fixP->fx_r_type > BFD_RELOC_XTENSA_SLOT14_OP)
++ continue;
++ xtensa_insnbuf_from_chars (isa, trampoline_buf,
++ (unsigned char *) fixP->fx_frag->fr_literal + fixP->fx_where,
++ 0);
++ fmt = xtensa_format_decode (isa, trampoline_buf);
++ gas_assert (fmt != XTENSA_UNDEFINED);
++ slot = fixP->tc_fix_data.slot;
++ xtensa_format_get_slot (isa, fmt, slot, trampoline_buf, trampoline_slotbuf);
++ opcode = xtensa_opcode_decode (isa, fmt, slot, trampoline_slotbuf);
++ if (opcode != xtensa_j_opcode)
++ continue;
++ target = S_GET_VALUE (s);
++ addr = fixP->fx_frag->fr_address;
++ delta = target - addr + stretch;
++ if (delta > J_RANGE || delta < -1 * J_RANGE)
++ { /* Found an out-of-range jump; scan the list of trampolines for the best match. */
++ struct trampoline_seg *ts = find_trampoline_seg (now_seg);
++ struct trampoline_frag *tf = ts->trampoline_list.next;
++ struct trampoline_frag *prev = &ts->trampoline_list;
++ int lower = (target < addr) ? target : addr;
++ int upper = (target > addr) ? target : addr;
++ int midpoint = lower + (upper - lower) / 2;
++
++ if ((upper - lower) > 2 * J_RANGE)
++ {
++ /* One trampoline won't suffice; we need multiple jumps.
++ Jump to the trampoline that's farthest, but still in
++ range relative to the original "j" instruction. */
++ for ( ; tf; prev = tf, tf = tf->next )
++ {
++ int this_addr = tf->fragP->fr_address + tf->fragP->fr_fix;
++ int next_addr = (tf->next) ? tf->next->fragP->fr_address + tf->next->fragP->fr_fix : 0 ;
++
++ if (addr == lower)
++ {
++ /* Forward jump. */
++ if (this_addr - addr < J_RANGE)
++ break;
++ }
++ else
++ {
++ /* Backward jump. */
++ if (next_addr == 0 || addr - next_addr > J_RANGE)
++ break;
++ }
++ }
++ }
++ else
++ {
++ struct trampoline_frag *best_tf = NULL;
++ int best_delta = 0;
++
++ for ( ; tf; prev = tf, tf = tf->next )
++ {
++ int this_addr = tf->fragP->fr_address + tf->fragP->fr_fix;
++ int this_delta = abs (this_addr - midpoint);
++
++ if (!best_tf || this_delta < best_delta)
++ {
++ best_tf = tf;
++ best_delta = this_delta;
++ }
++ }
++ tf = best_tf;
++ }
++ if (tf->fragP == fragP)
++ {
++ int trampaddr = fragP->fr_address + fragP->fr_fix;
++
++ if (abs (addr - trampaddr) < J_RANGE)
++ { /* The trampoline is in range of original; fix it! */
++ fixS *newfixP;
++ int offset;
++ TInsn insn;
++ symbolS *lsym;
++
++ new_stretch += init_trampoline_frag (tf);
++ offset = fragP->fr_fix; /* Where to assemble the j insn. */
++ lsym = fragP->fr_symbol;
++ fP = fixP->fx_frag;
++ /* Assemble a jump to the target label here. */
++ tinsn_init (&insn);
++ insn.insn_type = ITYPE_INSN;
++ insn.opcode = xtensa_j_opcode;
++ insn.ntok = 1;
++ set_expr_symbol_offset (&insn.tok[0], lsym, offset);
++ fmt = xg_get_single_format (xtensa_j_opcode);
++ tinsn_to_slotbuf (fmt, 0, &insn, trampoline_slotbuf);
++ xtensa_format_set_slot (isa, fmt, 0, trampoline_buf, trampoline_slotbuf);
++ xtensa_insnbuf_to_chars (isa, trampoline_buf, (unsigned char *)fragP->fr_literal + offset, 3);
++ fragP->fr_fix += 3;
++ fragP->fr_var -= 3;
++ /* Add a fix-up for the original j insn. */
++ newfixP = fix_new (fP, fixP->fx_where, fixP->fx_size, lsym, fragP->fr_fix - 3, TRUE, fixP->fx_r_type);
++ newfixP->fx_no_overflow = 1;
++ newfixP->tc_fix_data.X_add_symbol = lsym;
++ newfixP->tc_fix_data.X_add_number = offset;
++ newfixP->tc_fix_data.slot = slot;
++ /* Move the fix-up from the original j insn to this one. */
++ fixP->fx_frag = fragP;
++ fixP->fx_where = fragP->fr_fix - 3;
++ fixP->tc_fix_data.slot = 0;
++ /* Adjust the jump around this trampoline (if present). */
++ if (tf->fixP != NULL)
++ {
++ tf->fixP->fx_offset += 3;
++ }
++ new_stretch += 3;
++ fragP->tc_frag_data.relax_seen = FALSE; /* Need another pass. */
++ /* Do we have room for more? */
++ if (fragP->fr_var < 3)
++ { /* No, convert to fill. */
++ frag_wane (fragP);
++ fragP->fr_subtype = 0;
++ /* Remove from the trampoline_list. */
++ prev->next = tf->next;
++ break;
++ }
++ }
++ }
++ }
++ }
++ }
++ break;
++
+ default:
+ as_bad (_("bad relaxation state"));
+ }
+@@ -9146,6 +9472,200 @@ bytes_to_stretch (fragS *this_frag,
+ }
+
+
++static struct trampoline_frag *
++search_trampolines (TInsn *tinsn, fragS *fragP, bfd_boolean unreachable_only)
++{
++ struct trampoline_seg *ts = find_trampoline_seg (now_seg);
++ struct trampoline_frag *tf = (ts) ? ts->trampoline_list.next : NULL;
++ struct trampoline_frag *best_tf = NULL;
++ int best_delta = 0;
++ int best_addr = 0;
++ symbolS *sym = tinsn->tok[0].X_add_symbol;
++ offsetT target = S_GET_VALUE (sym) + tinsn->tok[0].X_add_number;
++ offsetT addr = fragP->fr_address;
++ offsetT lower = (addr < target) ? addr : target;
++ offsetT upper = (addr > target) ? addr : target;
++ int delta = upper - lower;
++ offsetT midpoint = lower + delta / 2;
++ int this_delta = -1;
++ int this_addr = -1;
++
++ if (delta > 2 * J_RANGE)
++ {
++ /* One trampoline won't do; we need multiple.
++ Choose the farthest trampoline that's still in range of the original
++ and let a later pass finish the job. */
++ for ( ; tf; tf = tf->next)
++ {
++ int next_addr = (tf->next) ? tf->next->fragP->fr_address + tf->next->fragP->fr_fix : 0;
++
++ this_addr = tf->fragP->fr_address + tf->fragP->fr_fix;
++ if (lower == addr)
++ {
++ /* Forward jump. */
++ if (this_addr - addr < J_RANGE)
++ break;
++ }
++ else
++ {
++ /* Backward jump. */
++ if (next_addr == 0 || addr - next_addr > J_RANGE)
++ break;
++ }
++ if (abs (addr - this_addr) < J_RANGE)
++ return tf;
++
++ return NULL;
++ }
++ }
++ for ( ; tf; tf = tf->next)
++ {
++ this_addr = tf->fragP->fr_address + tf->fragP->fr_fix;
++ this_delta = abs (this_addr - midpoint);
++ if (unreachable_only && tf->needs_jump_around)
++ continue;
++ if (!best_tf || this_delta < best_delta)
++ {
++ best_tf = tf;
++ best_delta = this_delta;
++ best_addr = this_addr;
++ }
++ }
++
++ if (best_tf &&
++ best_delta < J_RANGE &&
++ abs(best_addr - lower) < J_RANGE &&
++ abs(best_addr - upper) < J_RANGE)
++ return best_tf;
++
++ return NULL; /* No suitable trampoline found. */
++}
++
++
++static struct trampoline_frag *
++get_best_trampoline (TInsn *tinsn, fragS *fragP)
++{
++ struct trampoline_frag *tf = NULL;
++
++ tf = search_trampolines (tinsn, fragP, TRUE); /* Try unreachable first. */
++
++ if (tf == NULL)
++ tf = search_trampolines (tinsn, fragP, FALSE); /* Try ones needing a jump-around, too. */
++
++ return tf;
++}
++
++
++static void
++check_and_update_trampolines (void)
++{
++ struct trampoline_seg *ts = find_trampoline_seg (now_seg);
++ struct trampoline_frag *tf = ts->trampoline_list.next;
++ struct trampoline_frag *prev = &ts->trampoline_list;
++
++ for ( ; tf; prev = tf, tf = tf->next)
++ {
++ if (tf->fragP->fr_var < 3)
++ {
++ frag_wane (tf->fragP);
++ prev->next = tf->next;
++ tf->fragP = NULL;
++ }
++ }
++}
++
++
++static int
++init_trampoline_frag (struct trampoline_frag *trampP)
++{
++ fragS *fp = trampP->fragP;
++ int growth = 0;
++
++ if (fp->fr_fix == 0)
++ {
++ symbolS *lsym;
++ char label[10 + 2 * sizeof(fp)];
++ sprintf (label, ".L0_TR_%p", fp);
++
++ lsym = (symbolS *)local_symbol_make (label, now_seg, 0, fp);
++ fp->fr_symbol = lsym;
++ if (trampP->needs_jump_around)
++ {
++ /* Add a jump around this block of jumps, in case
++ control flows into this block. */
++ fixS *fixP;
++ TInsn insn;
++ xtensa_format fmt;
++ xtensa_isa isa = xtensa_default_isa;
++
++ fp->tc_frag_data.is_insn = 1;
++ /* Assemble a jump insn. */
++ tinsn_init (&insn);
++ insn.insn_type = ITYPE_INSN;
++ insn.opcode = xtensa_j_opcode;
++ insn.ntok = 1;
++ set_expr_symbol_offset (&insn.tok[0], lsym, 3);
++ fmt = xg_get_single_format (xtensa_j_opcode);
++ tinsn_to_slotbuf (fmt, 0, &insn, trampoline_slotbuf);
++ xtensa_format_set_slot (isa, fmt, 0, trampoline_buf, trampoline_slotbuf);
++ xtensa_insnbuf_to_chars (isa, trampoline_buf, (unsigned char *)fp->fr_literal, 3);
++ fp->fr_fix += 3;
++ fp->fr_var -= 3;
++ growth = 3;
++ fixP = fix_new (fp, 0, 3, lsym, 3, TRUE, BFD_RELOC_XTENSA_SLOT0_OP);
++ trampP->fixP = fixP;
++ }
++ }
++ return growth;
++}
++
++
++static int
++add_jump_to_trampoline (struct trampoline_frag *trampP, fragS *origfrag)
++{
++ fragS *tramp = trampP->fragP;
++ fixS *fixP;
++ int offset = tramp->fr_fix; /* Where to assemble the j insn. */
++ TInsn insn;
++ symbolS *lsym;
++ symbolS *tsym;
++ int toffset;
++ xtensa_format fmt;
++ xtensa_isa isa = xtensa_default_isa;
++ int growth = 0;
++
++ lsym = tramp->fr_symbol;
++ /* Assemble a jump to the target label in the trampoline frag. */
++ tsym = origfrag->tc_frag_data.slot_symbols[0];
++ toffset = origfrag-> tc_frag_data.slot_offsets[0];
++ tinsn_init (&insn);
++ insn.insn_type = ITYPE_INSN;
++ insn.opcode = xtensa_j_opcode;
++ insn.ntok = 1;
++ set_expr_symbol_offset (&insn.tok[0], tsym, toffset);
++ fmt = xg_get_single_format (xtensa_j_opcode);
++ tinsn_to_slotbuf (fmt, 0, &insn, trampoline_slotbuf);
++ xtensa_format_set_slot (isa, fmt, 0, trampoline_buf, trampoline_slotbuf);
++ xtensa_insnbuf_to_chars (isa, trampoline_buf, (unsigned char *)tramp->fr_literal + offset, 3);
++ tramp->fr_fix += 3;
++ tramp->fr_var -= 3;
++ growth = 3;
++ /* add a fix-up for the trampoline jump. */
++ fixP = fix_new (tramp, tramp->fr_fix - 3, 3, tsym, toffset, TRUE, BFD_RELOC_XTENSA_SLOT0_OP);
++ /* Modify the jump at the start of this trampoline to point past the newly-added jump. */
++ fixP = trampP->fixP;
++ if (fixP)
++ fixP->fx_offset += 3;
++ /* Modify the original j to point here. */
++ origfrag->tc_frag_data.slot_symbols[0] = lsym;
++ origfrag->tc_frag_data.slot_offsets[0] = tramp->fr_fix - 3;
++ /* If trampoline is full, remove it from the list. */
++ check_and_update_trampolines ();
++
++ return growth;
++}
++
++
+ static long
+ relax_frag_immed (segT segP,
+ fragS *fragP,
+@@ -9284,6 +9804,37 @@ relax_frag_immed (segT segP,
+ if (negatable_branch && istack.ninsn > 1)
+ update_next_frag_state (fragP);
+
++ /* If last insn is a jump, and it cannot reach its target, try to find a trampoline. */
++ if (istack.ninsn > 2 &&
++ istack.insn[istack.ninsn - 1].insn_type == ITYPE_LABEL &&
++ istack.insn[istack.ninsn - 2].insn_type == ITYPE_INSN &&
++ istack.insn[istack.ninsn - 2].opcode == xtensa_j_opcode)
++ {
++ TInsn *jinsn = &istack.insn[istack.ninsn - 2];
++
++ if (!xg_symbolic_immeds_fit (jinsn, segP, fragP, fragP->fr_offset, total_text_diff))
++ {
++ struct trampoline_frag *tf = get_best_trampoline (jinsn, fragP);
++
++ if (tf)
++ {
++ this_text_diff += init_trampoline_frag (tf);
++ this_text_diff += add_jump_to_trampoline (tf, fragP);
++ }
++ else
++ {
++ /* If target symbol is undefined, assume it will reach once linked. */
++ expressionS *exp = &istack.insn[istack.ninsn - 2].tok[0];
++
++ if (exp->X_op == O_symbol && S_IS_DEFINED (exp->X_add_symbol))
++ {
++ as_bad_where (fragP->fr_file, fragP->fr_line,
++ _("jump target out of range; no usable trampoline found"));
++ }
++ }
++ }
++ }
++
+ return this_text_diff;
+ }
+
+@@ -9404,6 +9955,9 @@ md_convert_frag (bfd *abfd ATTRIBUTE_UNUSED, segT sec, fragS *fragp)
+ else
+ as_bad (_("invalid relaxation fragment result"));
+ break;
++
++ case RELAX_TRAMPOLINE:
++ break;
+ }
+
+ fragp->fr_var = 0;
+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
+ };
+
+diff --git a/gas/frags.c b/gas/frags.c
+index 5f68480..e14099d 100644
+--- a/gas/frags.c
++++ b/gas/frags.c
+@@ -24,6 +24,20 @@
+
+ extern fragS zero_address_frag;
+ extern fragS predefined_address_frag;
++
++static int totalfrags;
++
++int
++get_frag_count (void)
++{
++ return totalfrags;
++}
++
++void
++clear_frag_count (void)
++{
++ totalfrags = 0;
++}
+ \f
+ /* Initialization for frag routines. */
+
+@@ -70,6 +84,7 @@ frag_alloc (struct obstack *ob)
+ ptr = (fragS *) obstack_alloc (ob, SIZEOF_STRUCT_FRAG);
+ obstack_alignment_mask (ob) = oalign;
+ memset (ptr, 0, SIZEOF_STRUCT_FRAG);
++ totalfrags++;
+ return ptr;
+ }
+ \f
+diff --git a/gas/frags.h b/gas/frags.h
+index 319898f..2f9e1b5 100644
+--- a/gas/frags.h
++++ b/gas/frags.h
+@@ -155,4 +155,7 @@ char *frag_var (relax_stateT type,
+
+ bfd_boolean frag_offset_fixed_p (const fragS *, const fragS *, offsetT *);
+
++int get_frag_count (void);
++void clear_frag_count (void);
++
+ #endif /* FRAGS_H */
+diff --git a/gas/testsuite/gas/xtensa/all.exp b/gas/testsuite/gas/xtensa/all.exp
+index 2b2c294..3683b78 100644
+--- a/gas/testsuite/gas/xtensa/all.exp
++++ b/gas/testsuite/gas/xtensa/all.exp
+@@ -98,6 +98,7 @@ if [istarget xtensa*-*-*] then {
+ run_dump_test "pcrel"
+ run_dump_test "weak-call"
+ run_dump_test "jlong"
++ run_dump_test "trampoline"
+ }
+
+ if [info exists errorInfo] then {
+diff --git a/gas/testsuite/gas/xtensa/trampoline.d b/gas/testsuite/gas/xtensa/trampoline.d
+new file mode 100644
+index 0000000..b4f65dc
+--- /dev/null
++++ b/gas/testsuite/gas/xtensa/trampoline.d
+@@ -0,0 +1,26 @@
++#as:
++#objdump: -d
++#name: trampolines relaxation
++
++.*: +file format .*xtensa.*
++#...
++.*0:.*j.0x1194c
++.*3:.*j.0x1194f
++.*6:.*j.0x11952
++.*9:.*j.0x1d4e4
++#...
++.*11949:.*j.0x11955
++.*1194c:.*j.0x24a0e
++.*1194f:.*j.0x24a0e
++.*11952:.*j.0x24a11
++#...
++.*1d4e1:.*j.0x1d4e7
++.*1d4e4:.*j.0x33462
++#...
++.*24a0e:.*j.0x24a0e
++.*24a11:.*j.0x24a11
++#...
++.*3345f:.*ret
++.*33462:.*j.0x49407
++#...
++.*49407:.*j.0x49407
+diff --git a/gas/testsuite/gas/xtensa/trampoline.s b/gas/testsuite/gas/xtensa/trampoline.s
+new file mode 100644
+index 0000000..259a3bb
+--- /dev/null
++++ b/gas/testsuite/gas/xtensa/trampoline.s
+@@ -0,0 +1,21 @@
++ .text
++ j 1f
++ j 1f
++ j 2f
++ j 3f
++ .rep 25000
++99:
++ and a2, a2, a3
++ bne a2, a3, 99b
++ .endr
++1:
++ j 1b
++2:
++ j 2b
++
++ .rep 25000
++ and a2, a2, a3
++ _ret
++ .endr
++3:
++ j 3b
+--
+1.8.1.4
+
Code Review / packages / trusty / cirros-testvm.git / blobdiff