From: bwilson Date: Tue, 29 Mar 2005 00:25:57 +0000 (+0000) Subject: * config/tc-xtensa.c (do_align_targets): Update comment. X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=b296a3232958b146fca4cee95fbfc9920f0fbac2;p=pf3gnuchains%2Fpf3gnuchains3x.git * config/tc-xtensa.c (do_align_targets): Update comment. (xtensa_frob_label): Compute "freq" before possibly switching frags. Insert a LOOP_END frag before every loop target, and do not overload DESIRE_ALIGN_IF_TARGET frags with loop end information. (xg_assemble_vliw_tokens): Use do_align_targets. (xtensa_fix_target_frags): Remove code to convert a DESIRE_ALIGN_IF_TARGET frag to a LOOP_END frag when there is a negatable branch at the end of a loop. (frag_can_negate_branch): Delete. --- diff --git a/gas/ChangeLog b/gas/ChangeLog index 3fef8debb5..f45d92539a 100644 --- a/gas/ChangeLog +++ b/gas/ChangeLog @@ -1,3 +1,16 @@ +2005-03-28 Sterling Augustine + Bob Wilson + + * config/tc-xtensa.c (do_align_targets): Update comment. + (xtensa_frob_label): Compute "freq" before possibly switching frags. + Insert a LOOP_END frag before every loop target, and do not overload + DESIRE_ALIGN_IF_TARGET frags with loop end information. + (xg_assemble_vliw_tokens): Use do_align_targets. + (xtensa_fix_target_frags): Remove code to convert a + DESIRE_ALIGN_IF_TARGET frag to a LOOP_END frag when there is a + negatable branch at the end of a loop. + (frag_can_negate_branch): Delete. + 2005-03-28 David Mosberger H.J. Lu @@ -307,7 +320,8 @@ * configure: Regenerate. * config/obj-vms.h, config/obj-vms.c, config/vms-conf.h: Remove. -2005-03-10 Bob Wilson +2005-03-10 Sterling Augustine + Bob Wilson * config/tc-xtensa.c (finish_vinsn): Include the last instruction slot when checking if xg_resolve_literals needs to be called. diff --git a/gas/config/tc-xtensa.c b/gas/config/tc-xtensa.c index 0bebbd0084..907029f72b 100644 --- a/gas/config/tc-xtensa.c +++ b/gas/config/tc-xtensa.c @@ -1033,8 +1033,9 @@ use_transform (void) static bfd_boolean do_align_targets (void) { - /* After md_end, you should be checking frag by frag, rather - than state directives. */ + /* Do not use this function after md_end; just look at align_targets + instead. There is no target-align directive, so alignment is either + enabled for all frags or not done at all. */ assert (!past_xtensa_end); return align_targets && use_transform (); } @@ -4525,7 +4526,7 @@ update_next_frag_state (fragS *fragP) fragS *next_fragP = fragP->fr_next; fragS *new_target = NULL; - if (align_targets) + if (align_targets) { /* We are guaranteed there will be one of these... */ while (!(next_fragP->fr_type == rs_machine_dependent @@ -5077,6 +5078,8 @@ xtensa_init_fix_data (fixS *x) void xtensa_frob_label (symbolS *sym) { + float freq = get_subseg_target_freq (now_seg, now_subseg); + /* Since the label was already attached to a frag associated with the previous basic block, it now needs to be reset to the current frag. */ symbol_set_frag (sym, frag_now); @@ -5087,10 +5090,19 @@ xtensa_frob_label (symbolS *sym) else xtensa_add_insn_label (sym); - if (symbol_get_tc (sym)->is_loop_target - && (get_last_insn_flags (now_seg, now_subseg) + if (symbol_get_tc (sym)->is_loop_target) + { + if ((get_last_insn_flags (now_seg, now_subseg) & FLAG_IS_BAD_LOOPEND) != 0) - as_bad (_("invalid last instruction for a zero-overhead loop")); + as_bad (_("invalid last instruction for a zero-overhead loop")); + + xtensa_set_frag_assembly_state (frag_now); + frag_var (rs_machine_dependent, 4, 4, RELAX_LOOP_END, + frag_now->fr_symbol, frag_now->fr_offset, NULL); + + xtensa_set_frag_assembly_state (frag_now); + xtensa_move_labels (frag_now, 0, TRUE); + } /* No target aligning in the absolute section. */ if (now_seg != absolute_section @@ -5098,26 +5110,10 @@ xtensa_frob_label (symbolS *sym) && !is_unaligned_label (sym) && !generating_literals) { - float freq = get_subseg_target_freq (now_seg, now_subseg); xtensa_set_frag_assembly_state (frag_now); - /* The only time this type of frag grows is when there is a - negatable branch that needs to be relaxed as the last - instruction in a zero-overhead loop. Because alignment frags - are so common, marking them all as possibly growing four - bytes makes any worst-case analysis appear much worse than it - is. So, we make fr_var not actually reflect the amount of - memory allocated at the end of this frag, but rather the - amount of memory this frag might grow. The "4, 0" below - allocates four bytes at the end of the frag for room to grow - if we need to relax a loop end with a NOP. Frags prior to - this one might grow to align this one, but the frag itself - won't grow unless it meets the condition above. */ - -#define RELAX_LOOP_END_BYTES 4 - frag_var (rs_machine_dependent, - RELAX_LOOP_END_BYTES, (int) freq, + 0, (int) freq, RELAX_DESIRE_ALIGN_IF_TARGET, frag_now->fr_symbol, frag_now->fr_offset, NULL); xtensa_set_frag_assembly_state (frag_now); @@ -6937,7 +6933,7 @@ xg_assemble_vliw_tokens (vliw_insn *vinsn) frag_now->fr_symbol, frag_now->fr_offset, NULL); xtensa_set_frag_assembly_state (frag_now); } - else if (is_branch && align_targets) + else if (is_branch && do_align_targets ()) { assert (finish_frag); frag_var (rs_machine_dependent, @@ -7064,11 +7060,7 @@ xtensa_cleanup_align_frags (void) /* Re-process all of the fragments looking to convert all of the RELAX_DESIRE_ALIGN_IF_TARGET fragments. If there is a branch target in the next fragment, convert this to RELAX_DESIRE_ALIGN. - If the next fragment starts with a loop target, AND the previous - fragment can be expanded to negate the branch, convert this to a - RELAX_LOOP_END. Otherwise, convert to a .fill 0. */ - -static bfd_boolean frag_can_negate_branch (fragS *); + Otherwise, convert to a .fill 0. */ static void xtensa_fix_target_frags (void) @@ -7079,7 +7071,6 @@ xtensa_fix_target_frags (void) so we walk over subsections instead of sections. */ for (frchP = frchain_root; frchP; frchP = frchP->frch_next) { - bfd_boolean prev_frag_can_negate_branch = FALSE; fragS *fragP; /* Walk over all of the fragments in a subsection. */ @@ -7088,61 +7079,16 @@ xtensa_fix_target_frags (void) if (fragP->fr_type == rs_machine_dependent && fragP->fr_subtype == RELAX_DESIRE_ALIGN_IF_TARGET) { - if (next_frag_is_loop_target (fragP)) - { - if (prev_frag_can_negate_branch) - { - fragP->fr_subtype = RELAX_LOOP_END; - /* See the comment near the frag_var with a - RELAX_DESIRE_ALIGN to see why we do this. */ - fragP->fr_var = RELAX_LOOP_END_BYTES; - } - else - { - if (next_frag_is_branch_target (fragP)) - fragP->fr_subtype = RELAX_DESIRE_ALIGN; - else - frag_wane (fragP); - } - } - else if (next_frag_is_branch_target (fragP)) + if (next_frag_is_branch_target (fragP)) fragP->fr_subtype = RELAX_DESIRE_ALIGN; else frag_wane (fragP); } - if (fragP->fr_fix != 0) - prev_frag_can_negate_branch = FALSE; - if (frag_can_negate_branch (fragP)) - prev_frag_can_negate_branch = TRUE; } } } -static bfd_boolean -frag_can_negate_branch (fragS *fragP) -{ - xtensa_isa isa = xtensa_default_isa; - vliw_insn vinsn; - int slot; - - if (fragP->fr_type != rs_machine_dependent - || fragP->fr_subtype != RELAX_SLOTS) - return FALSE; - - vinsn_from_chars (&vinsn, fragP->fr_opcode); - - for (slot = 0; slot < xtensa_format_num_slots (isa, vinsn.format); slot++) - { - if ((fragP->tc_frag_data.slot_subtypes[slot] == RELAX_IMMED) - && xtensa_opcode_is_branch (isa, vinsn.slots[slot].opcode) == 1) - return TRUE; - } - - return FALSE; -} - - static bfd_boolean is_narrow_branch_guaranteed_in_range (fragS *, TInsn *); static void