kumquat-buildroot/package/binutils/2.24/900-xtensa-trampolines.patch
Max Filippov c09b2bfaea binutils: drop *.texi* hunks from xtensa trampolines patches
Rebuilding as.info with makeinfo version 5.2 results in a build error,
even with pristine binutils source. Dropping hunks that change *.texi*
files avoids documentation rebuild.

Reported-by: Vincent Stehlé <vincent.stehle@freescale.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
2014-04-05 18:36:39 +02:00

847 lines
24 KiB
Diff
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

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);
}
@@ -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;
+}
/* 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;
}
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