diff options
Diffstat (limited to 'binutils-2.25/gas/config/tc-xtensa.c')
| -rw-r--r-- | binutils-2.25/gas/config/tc-xtensa.c | 567 |
1 files changed, 561 insertions, 6 deletions
diff --git a/binutils-2.25/gas/config/tc-xtensa.c b/binutils-2.25/gas/config/tc-xtensa.c index 70755310..d11b0c7f 100644 --- a/binutils-2.25/gas/config/tc-xtensa.c +++ b/binutils-2.25/gas/config/tc-xtensa.c @@ -1,6 +1,5 @@ /* tc-xtensa.c -- Assemble Xtensa instructions. - Copyright 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 - Free Software Foundation, Inc. + Copyright (C) 2003-2014 Free Software Foundation, Inc. This file is part of GAS, the GNU Assembler. @@ -469,6 +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. */ @@ -521,6 +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. */ @@ -688,7 +694,10 @@ enum option_prefer_l32r, option_prefer_const16, - option_target_hardware + option_target_hardware, + + option_trampolines, + option_no_trampolines, }; const char *md_shortopts = ""; @@ -761,6 +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 } }; @@ -941,6 +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; } @@ -964,7 +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); } @@ -5569,6 +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 (); } @@ -5585,7 +5609,6 @@ xtensa_handle_align (fragS *fragP) && ! fragP->tc_frag_data.is_literal && (fragP->fr_type == rs_align || fragP->fr_type == rs_align_code) - && fragP->fr_address + fragP->fr_fix > 0 && fragP->fr_offset > 0 && now_seg != bss_section) { @@ -5844,12 +5867,15 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg) { case BFD_RELOC_8: fixP->fx_r_type = BFD_RELOC_XTENSA_DIFF8; + fixP->fx_signed = 1; break; case BFD_RELOC_16: fixP->fx_r_type = BFD_RELOC_XTENSA_DIFF16; + fixP->fx_signed = 1; break; case BFD_RELOC_32: fixP->fx_r_type = BFD_RELOC_XTENSA_DIFF32; + fixP->fx_signed = 1; break; default: break; @@ -6373,6 +6399,8 @@ finish_vinsn (vliw_insn *vinsn) xg_assemble_vliw_tokens (vinsn); xg_clear_vinsn (vinsn); + + xtensa_check_frag_count (); } @@ -6935,7 +6963,7 @@ xg_assemble_vliw_tokens (vliw_insn *vinsn) if (frag_now_fix () != 0 && (! frag_now->tc_frag_data.is_insn || (vinsn_has_specific_opcodes (vinsn) && use_transform ()) - || !use_transform () != frag_now->tc_frag_data.is_no_transform + || (!use_transform ()) != frag_now->tc_frag_data.is_no_transform || (directive_state[directive_longcalls] != frag_now->tc_frag_data.use_longcalls) || (directive_state[directive_absolute_literals] @@ -7141,6 +7169,7 @@ 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 ()) { @@ -7223,9 +7252,164 @@ 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) { @@ -8709,6 +8893,149 @@ 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")); } @@ -9147,6 +9474,200 @@ 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, @@ -9285,6 +9806,37 @@ 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; } @@ -9405,6 +9957,9 @@ 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; |