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Diffstat (limited to 'gcc-4.2.1/gcc/cfgrtl.c')
| -rw-r--r-- | gcc-4.2.1/gcc/cfgrtl.c | 3105 |
1 files changed, 0 insertions, 3105 deletions
diff --git a/gcc-4.2.1/gcc/cfgrtl.c b/gcc-4.2.1/gcc/cfgrtl.c deleted file mode 100644 index 5a7bf1a02..000000000 --- a/gcc-4.2.1/gcc/cfgrtl.c +++ /dev/null @@ -1,3105 +0,0 @@ -/* Control flow graph manipulation code for GNU compiler. - Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, - 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc. - -This file is part of GCC. - -GCC is free software; you can redistribute it and/or modify it under -the terms of the GNU General Public License as published by the Free -Software Foundation; either version 2, or (at your option) any later -version. - -GCC is distributed in the hope that it will be useful, but WITHOUT ANY -WARRANTY; without even the implied warranty of MERCHANTABILITY or -FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -for more details. - -You should have received a copy of the GNU General Public License -along with GCC; see the file COPYING. If not, write to the Free -Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA -02110-1301, USA. */ - -/* This file contains low level functions to manipulate the CFG and analyze it - that are aware of the RTL intermediate language. - - Available functionality: - - Basic CFG/RTL manipulation API documented in cfghooks.h - - CFG-aware instruction chain manipulation - delete_insn, delete_insn_chain - - Edge splitting and committing to edges - insert_insn_on_edge, commit_edge_insertions - - CFG updating after insn simplification - purge_dead_edges, purge_all_dead_edges - - Functions not supposed for generic use: - - Infrastructure to determine quickly basic block for insn - compute_bb_for_insn, update_bb_for_insn, set_block_for_insn, - - Edge redirection with updating and optimizing of insn chain - block_label, tidy_fallthru_edge, force_nonfallthru */ - -#include "config.h" -#include "system.h" -#include "coretypes.h" -#include "tm.h" -#include "tree.h" -#include "rtl.h" -#include "hard-reg-set.h" -#include "basic-block.h" -#include "regs.h" -#include "flags.h" -#include "output.h" -#include "function.h" -#include "except.h" -#include "toplev.h" -#include "tm_p.h" -#include "obstack.h" -#include "insn-config.h" -#include "cfglayout.h" -#include "expr.h" -#include "target.h" -#include "cfgloop.h" -#include "ggc.h" -#include "tree-pass.h" - -static int can_delete_note_p (rtx); -static int can_delete_label_p (rtx); -static void commit_one_edge_insertion (edge, int); -static basic_block rtl_split_edge (edge); -static bool rtl_move_block_after (basic_block, basic_block); -static int rtl_verify_flow_info (void); -static basic_block cfg_layout_split_block (basic_block, void *); -static edge cfg_layout_redirect_edge_and_branch (edge, basic_block); -static basic_block cfg_layout_redirect_edge_and_branch_force (edge, basic_block); -static void cfg_layout_delete_block (basic_block); -static void rtl_delete_block (basic_block); -static basic_block rtl_redirect_edge_and_branch_force (edge, basic_block); -static edge rtl_redirect_edge_and_branch (edge, basic_block); -static basic_block rtl_split_block (basic_block, void *); -static void rtl_dump_bb (basic_block, FILE *, int); -static int rtl_verify_flow_info_1 (void); -static void rtl_make_forwarder_block (edge); - -/* Return true if NOTE is not one of the ones that must be kept paired, - so that we may simply delete it. */ - -static int -can_delete_note_p (rtx note) -{ - return (NOTE_LINE_NUMBER (note) == NOTE_INSN_DELETED - || NOTE_LINE_NUMBER (note) == NOTE_INSN_BASIC_BLOCK); -} - -/* True if a given label can be deleted. */ - -static int -can_delete_label_p (rtx label) -{ - return (!LABEL_PRESERVE_P (label) - /* User declared labels must be preserved. */ - && LABEL_NAME (label) == 0 - && !in_expr_list_p (forced_labels, label)); -} - -/* Delete INSN by patching it out. Return the next insn. */ - -rtx -delete_insn (rtx insn) -{ - rtx next = NEXT_INSN (insn); - rtx note; - bool really_delete = true; - - if (LABEL_P (insn)) - { - /* Some labels can't be directly removed from the INSN chain, as they - might be references via variables, constant pool etc. - Convert them to the special NOTE_INSN_DELETED_LABEL note. */ - if (! can_delete_label_p (insn)) - { - const char *name = LABEL_NAME (insn); - - really_delete = false; - PUT_CODE (insn, NOTE); - NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED_LABEL; - NOTE_DELETED_LABEL_NAME (insn) = name; - } - - remove_node_from_expr_list (insn, &nonlocal_goto_handler_labels); - } - - if (really_delete) - { - /* If this insn has already been deleted, something is very wrong. */ - gcc_assert (!INSN_DELETED_P (insn)); - remove_insn (insn); - INSN_DELETED_P (insn) = 1; - } - - /* If deleting a jump, decrement the use count of the label. Deleting - the label itself should happen in the normal course of block merging. */ - if (JUMP_P (insn) - && JUMP_LABEL (insn) - && LABEL_P (JUMP_LABEL (insn))) - LABEL_NUSES (JUMP_LABEL (insn))--; - - /* Also if deleting an insn that references a label. */ - else - { - while ((note = find_reg_note (insn, REG_LABEL, NULL_RTX)) != NULL_RTX - && LABEL_P (XEXP (note, 0))) - { - LABEL_NUSES (XEXP (note, 0))--; - remove_note (insn, note); - } - } - - if (JUMP_P (insn) - && (GET_CODE (PATTERN (insn)) == ADDR_VEC - || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)) - { - rtx pat = PATTERN (insn); - int diff_vec_p = GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC; - int len = XVECLEN (pat, diff_vec_p); - int i; - - for (i = 0; i < len; i++) - { - rtx label = XEXP (XVECEXP (pat, diff_vec_p, i), 0); - - /* When deleting code in bulk (e.g. removing many unreachable - blocks) we can delete a label that's a target of the vector - before deleting the vector itself. */ - if (!NOTE_P (label)) - LABEL_NUSES (label)--; - } - } - - return next; -} - -/* Like delete_insn but also purge dead edges from BB. */ -rtx -delete_insn_and_edges (rtx insn) -{ - rtx x; - bool purge = false; - - if (INSN_P (insn) - && BLOCK_FOR_INSN (insn) - && BB_END (BLOCK_FOR_INSN (insn)) == insn) - purge = true; - x = delete_insn (insn); - if (purge) - purge_dead_edges (BLOCK_FOR_INSN (insn)); - return x; -} - -/* Unlink a chain of insns between START and FINISH, leaving notes - that must be paired. */ - -void -delete_insn_chain (rtx start, rtx finish) -{ - rtx next; - - /* Unchain the insns one by one. It would be quicker to delete all of these - with a single unchaining, rather than one at a time, but we need to keep - the NOTE's. */ - while (1) - { - next = NEXT_INSN (start); - if (NOTE_P (start) && !can_delete_note_p (start)) - ; - else - next = delete_insn (start); - - if (start == finish) - break; - start = next; - } -} - -/* Like delete_insn but also purge dead edges from BB. */ -void -delete_insn_chain_and_edges (rtx first, rtx last) -{ - bool purge = false; - - if (INSN_P (last) - && BLOCK_FOR_INSN (last) - && BB_END (BLOCK_FOR_INSN (last)) == last) - purge = true; - delete_insn_chain (first, last); - if (purge) - purge_dead_edges (BLOCK_FOR_INSN (last)); -} - -/* Create a new basic block consisting of the instructions between HEAD and END - inclusive. This function is designed to allow fast BB construction - reuses - the note and basic block struct in BB_NOTE, if any and do not grow - BASIC_BLOCK chain and should be used directly only by CFG construction code. - END can be NULL in to create new empty basic block before HEAD. Both END - and HEAD can be NULL to create basic block at the end of INSN chain. - AFTER is the basic block we should be put after. */ - -basic_block -create_basic_block_structure (rtx head, rtx end, rtx bb_note, basic_block after) -{ - basic_block bb; - - if (bb_note - && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL - && bb->aux == NULL) - { - /* If we found an existing note, thread it back onto the chain. */ - - rtx after; - - if (LABEL_P (head)) - after = head; - else - { - after = PREV_INSN (head); - head = bb_note; - } - - if (after != bb_note && NEXT_INSN (after) != bb_note) - reorder_insns_nobb (bb_note, bb_note, after); - } - else - { - /* Otherwise we must create a note and a basic block structure. */ - - bb = alloc_block (); - - init_rtl_bb_info (bb); - if (!head && !end) - head = end = bb_note - = emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ()); - else if (LABEL_P (head) && end) - { - bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head); - if (head == end) - end = bb_note; - } - else - { - bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head); - head = bb_note; - if (!end) - end = head; - } - - NOTE_BASIC_BLOCK (bb_note) = bb; - } - - /* Always include the bb note in the block. */ - if (NEXT_INSN (end) == bb_note) - end = bb_note; - - BB_HEAD (bb) = head; - BB_END (bb) = end; - bb->index = last_basic_block++; - bb->flags = BB_NEW | BB_RTL; - link_block (bb, after); - SET_BASIC_BLOCK (bb->index, bb); - update_bb_for_insn (bb); - BB_SET_PARTITION (bb, BB_UNPARTITIONED); - - /* Tag the block so that we know it has been used when considering - other basic block notes. */ - bb->aux = bb; - - return bb; -} - -/* Create new basic block consisting of instructions in between HEAD and END - and place it to the BB chain after block AFTER. END can be NULL in to - create new empty basic block before HEAD. Both END and HEAD can be NULL to - create basic block at the end of INSN chain. */ - -static basic_block -rtl_create_basic_block (void *headp, void *endp, basic_block after) -{ - rtx head = headp, end = endp; - basic_block bb; - - /* Grow the basic block array if needed. */ - if ((size_t) last_basic_block >= VEC_length (basic_block, basic_block_info)) - { - size_t old_size = VEC_length (basic_block, basic_block_info); - size_t new_size = last_basic_block + (last_basic_block + 3) / 4; - basic_block *p; - VEC_safe_grow (basic_block, gc, basic_block_info, new_size); - p = VEC_address (basic_block, basic_block_info); - memset (&p[old_size], 0, sizeof (basic_block) * (new_size - old_size)); - } - - n_basic_blocks++; - - bb = create_basic_block_structure (head, end, NULL, after); - bb->aux = NULL; - return bb; -} - -static basic_block -cfg_layout_create_basic_block (void *head, void *end, basic_block after) -{ - basic_block newbb = rtl_create_basic_block (head, end, after); - - return newbb; -} - -/* Delete the insns in a (non-live) block. We physically delete every - non-deleted-note insn, and update the flow graph appropriately. - - Return nonzero if we deleted an exception handler. */ - -/* ??? Preserving all such notes strikes me as wrong. It would be nice - to post-process the stream to remove empty blocks, loops, ranges, etc. */ - -static void -rtl_delete_block (basic_block b) -{ - rtx insn, end; - - /* If the head of this block is a CODE_LABEL, then it might be the - label for an exception handler which can't be reached. We need - to remove the label from the exception_handler_label list. */ - insn = BB_HEAD (b); - if (LABEL_P (insn)) - maybe_remove_eh_handler (insn); - - end = get_last_bb_insn (b); - - /* Selectively delete the entire chain. */ - BB_HEAD (b) = NULL; - delete_insn_chain (insn, end); - if (b->il.rtl->global_live_at_start) - { - FREE_REG_SET (b->il.rtl->global_live_at_start); - FREE_REG_SET (b->il.rtl->global_live_at_end); - b->il.rtl->global_live_at_start = NULL; - b->il.rtl->global_live_at_end = NULL; - } -} - -/* Records the basic block struct in BLOCK_FOR_INSN for every insn. */ - -void -compute_bb_for_insn (void) -{ - basic_block bb; - - FOR_EACH_BB (bb) - { - rtx end = BB_END (bb); - rtx insn; - - for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) - { - BLOCK_FOR_INSN (insn) = bb; - if (insn == end) - break; - } - } -} - -/* Release the basic_block_for_insn array. */ - -unsigned int -free_bb_for_insn (void) -{ - rtx insn; - for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) - if (!BARRIER_P (insn)) - BLOCK_FOR_INSN (insn) = NULL; - return 0; -} - -struct tree_opt_pass pass_free_cfg = -{ - NULL, /* name */ - NULL, /* gate */ - free_bb_for_insn, /* execute */ - NULL, /* sub */ - NULL, /* next */ - 0, /* static_pass_number */ - 0, /* tv_id */ - 0, /* properties_required */ - 0, /* properties_provided */ - PROP_cfg, /* properties_destroyed */ - 0, /* todo_flags_start */ - 0, /* todo_flags_finish */ - 0 /* letter */ -}; - -/* Return RTX to emit after when we want to emit code on the entry of function. */ -rtx -entry_of_function (void) -{ - return (n_basic_blocks > NUM_FIXED_BLOCKS ? - BB_HEAD (ENTRY_BLOCK_PTR->next_bb) : get_insns ()); -} - -/* Like entry_of_function except it returns NULL when entry_of_function would fault. */ -rtx -entry_of_function_safe (void) -{ - if (n_basic_blocks > NUM_FIXED_BLOCKS) - return ((ENTRY_BLOCK_PTR->next_bb->il.rtl) - ? BB_HEAD (ENTRY_BLOCK_PTR->next_bb) : NULL_RTX); - else - return get_insns (); -} - -/* Emit INSN at the entry point of the function, ensuring that it is only - executed once per function. */ -void -emit_insn_at_entry (rtx insn) -{ - edge_iterator ei = ei_start (ENTRY_BLOCK_PTR->succs); - edge e = ei_safe_edge (ei); - gcc_assert (e->flags & EDGE_FALLTHRU); - - insert_insn_on_edge (insn, e); - commit_edge_insertions (); -} - -/* Update insns block within BB. */ - -void -update_bb_for_insn (basic_block bb) -{ - rtx insn; - - for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn)) - { - if (!BARRIER_P (insn)) - set_block_for_insn (insn, bb); - if (insn == BB_END (bb)) - break; - } -} - -/* Creates a new basic block just after basic block B by splitting - everything after specified instruction I. */ - -static basic_block -rtl_split_block (basic_block bb, void *insnp) -{ - basic_block new_bb; - rtx insn = insnp; - edge e; - edge_iterator ei; - - if (!insn) - { - insn = first_insn_after_basic_block_note (bb); - - if (insn) - insn = PREV_INSN (insn); - else - insn = get_last_insn (); - } - - /* We probably should check type of the insn so that we do not create - inconsistent cfg. It is checked in verify_flow_info anyway, so do not - bother. */ - if (insn == BB_END (bb)) - emit_note_after (NOTE_INSN_DELETED, insn); - - /* Create the new basic block. */ - new_bb = create_basic_block (NEXT_INSN (insn), BB_END (bb), bb); - BB_COPY_PARTITION (new_bb, bb); - BB_END (bb) = insn; - - /* Redirect the outgoing edges. */ - new_bb->succs = bb->succs; - bb->succs = NULL; - FOR_EACH_EDGE (e, ei, new_bb->succs) - e->src = new_bb; - - if (bb->il.rtl->global_live_at_start) - { - new_bb->il.rtl->global_live_at_start = ALLOC_REG_SET (®_obstack); - new_bb->il.rtl->global_live_at_end = ALLOC_REG_SET (®_obstack); - COPY_REG_SET (new_bb->il.rtl->global_live_at_end, bb->il.rtl->global_live_at_end); - - /* We now have to calculate which registers are live at the end - of the split basic block and at the start of the new basic - block. Start with those registers that are known to be live - at the end of the original basic block and get - propagate_block to determine which registers are live. */ - COPY_REG_SET (new_bb->il.rtl->global_live_at_start, bb->il.rtl->global_live_at_end); - propagate_block (new_bb, new_bb->il.rtl->global_live_at_start, NULL, NULL, 0); - COPY_REG_SET (bb->il.rtl->global_live_at_end, - new_bb->il.rtl->global_live_at_start); -#ifdef HAVE_conditional_execution - /* In the presence of conditional execution we are not able to update - liveness precisely. */ - if (reload_completed) - { - bb->flags |= BB_DIRTY; - new_bb->flags |= BB_DIRTY; - } -#endif - } - - return new_bb; -} - -/* Blocks A and B are to be merged into a single block A. The insns - are already contiguous. */ - -static void -rtl_merge_blocks (basic_block a, basic_block b) -{ - rtx b_head = BB_HEAD (b), b_end = BB_END (b), a_end = BB_END (a); - rtx del_first = NULL_RTX, del_last = NULL_RTX; - int b_empty = 0; - - /* If there was a CODE_LABEL beginning B, delete it. */ - if (LABEL_P (b_head)) - { - /* This might have been an EH label that no longer has incoming - EH edges. Update data structures to match. */ - maybe_remove_eh_handler (b_head); - - /* Detect basic blocks with nothing but a label. This can happen - in particular at the end of a function. */ - if (b_head == b_end) - b_empty = 1; - - del_first = del_last = b_head; - b_head = NEXT_INSN (b_head); - } - - /* Delete the basic block note and handle blocks containing just that - note. */ - if (NOTE_INSN_BASIC_BLOCK_P (b_head)) - { - if (b_head == b_end) - b_empty = 1; - if (! del_last) - del_first = b_head; - - del_last = b_head; - b_head = NEXT_INSN (b_head); - } - - /* If there was a jump out of A, delete it. */ - if (JUMP_P (a_end)) - { - rtx prev; - - for (prev = PREV_INSN (a_end); ; prev = PREV_INSN (prev)) - if (!NOTE_P (prev) - || NOTE_LINE_NUMBER (prev) == NOTE_INSN_BASIC_BLOCK - || prev == BB_HEAD (a)) - break; - - del_first = a_end; - -#ifdef HAVE_cc0 - /* If this was a conditional jump, we need to also delete - the insn that set cc0. */ - if (only_sets_cc0_p (prev)) - { - rtx tmp = prev; - - prev = prev_nonnote_insn (prev); - if (!prev) - prev = BB_HEAD (a); - del_first = tmp; - } -#endif - - a_end = PREV_INSN (del_first); - } - else if (BARRIER_P (NEXT_INSN (a_end))) - del_first = NEXT_INSN (a_end); - - /* Delete everything marked above as well as crap that might be - hanging out between the two blocks. */ - BB_HEAD (b) = NULL; - delete_insn_chain (del_first, del_last); - - /* Reassociate the insns of B with A. */ - if (!b_empty) - { - rtx x; - - for (x = a_end; x != b_end; x = NEXT_INSN (x)) - set_block_for_insn (x, a); - - set_block_for_insn (b_end, a); - - a_end = b_end; - } - - BB_END (a) = a_end; - a->il.rtl->global_live_at_end = b->il.rtl->global_live_at_end; -} - -/* Return true when block A and B can be merged. */ -static bool -rtl_can_merge_blocks (basic_block a,basic_block b) -{ - /* If we are partitioning hot/cold basic blocks, we don't want to - mess up unconditional or indirect jumps that cross between hot - and cold sections. - - Basic block partitioning may result in some jumps that appear to - be optimizable (or blocks that appear to be mergeable), but which really - must be left untouched (they are required to make it safely across - partition boundaries). See the comments at the top of - bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ - - if (BB_PARTITION (a) != BB_PARTITION (b)) - return false; - - /* There must be exactly one edge in between the blocks. */ - return (single_succ_p (a) - && single_succ (a) == b - && single_pred_p (b) - && a != b - /* Must be simple edge. */ - && !(single_succ_edge (a)->flags & EDGE_COMPLEX) - && a->next_bb == b - && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR - /* If the jump insn has side effects, - we can't kill the edge. */ - && (!JUMP_P (BB_END (a)) - || (reload_completed - ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); -} - -/* Return the label in the head of basic block BLOCK. Create one if it doesn't - exist. */ - -rtx -block_label (basic_block block) -{ - if (block == EXIT_BLOCK_PTR) - return NULL_RTX; - - if (!LABEL_P (BB_HEAD (block))) - { - BB_HEAD (block) = emit_label_before (gen_label_rtx (), BB_HEAD (block)); - } - - return BB_HEAD (block); -} - -/* Attempt to perform edge redirection by replacing possibly complex jump - instruction by unconditional jump or removing jump completely. This can - apply only if all edges now point to the same block. The parameters and - return values are equivalent to redirect_edge_and_branch. */ - -edge -try_redirect_by_replacing_jump (edge e, basic_block target, bool in_cfglayout) -{ - basic_block src = e->src; - rtx insn = BB_END (src), kill_from; - rtx set; - int fallthru = 0; - - /* If we are partitioning hot/cold basic blocks, we don't want to - mess up unconditional or indirect jumps that cross between hot - and cold sections. - - Basic block partitioning may result in some jumps that appear to - be optimizable (or blocks that appear to be mergeable), but which really - must be left untouched (they are required to make it safely across - partition boundaries). See the comments at the top of - bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ - - if (find_reg_note (insn, REG_CROSSING_JUMP, NULL_RTX) - || BB_PARTITION (src) != BB_PARTITION (target)) - return NULL; - - /* We can replace or remove a complex jump only when we have exactly - two edges. Also, if we have exactly one outgoing edge, we can - redirect that. */ - if (EDGE_COUNT (src->succs) >= 3 - /* Verify that all targets will be TARGET. Specifically, the - edge that is not E must also go to TARGET. */ - || (EDGE_COUNT (src->succs) == 2 - && EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target)) - return NULL; - - if (!onlyjump_p (insn)) - return NULL; - if ((!optimize || reload_completed) && tablejump_p (insn, NULL, NULL)) - return NULL; - - /* Avoid removing branch with side effects. */ - set = single_set (insn); - if (!set || side_effects_p (set)) - return NULL; - - /* In case we zap a conditional jump, we'll need to kill - the cc0 setter too. */ - kill_from = insn; -#ifdef HAVE_cc0 - if (reg_mentioned_p (cc0_rtx, PATTERN (insn))) - kill_from = PREV_INSN (insn); -#endif - - /* See if we can create the fallthru edge. */ - if (in_cfglayout || can_fallthru (src, target)) - { - if (dump_file) - fprintf (dump_file, "Removing jump %i.\n", INSN_UID (insn)); - fallthru = 1; - - /* Selectively unlink whole insn chain. */ - if (in_cfglayout) - { - rtx insn = src->il.rtl->footer; - - delete_insn_chain (kill_from, BB_END (src)); - - /* Remove barriers but keep jumptables. */ - while (insn) - { - if (BARRIER_P (insn)) - { - if (PREV_INSN (insn)) - NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); - else - src->il.rtl->footer = NEXT_INSN (insn); - if (NEXT_INSN (insn)) - PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); - } - if (LABEL_P (insn)) - break; - insn = NEXT_INSN (insn); - } - } - else - delete_insn_chain (kill_from, PREV_INSN (BB_HEAD (target))); - } - - /* If this already is simplejump, redirect it. */ - else if (simplejump_p (insn)) - { - if (e->dest == target) - return NULL; - if (dump_file) - fprintf (dump_file, "Redirecting jump %i from %i to %i.\n", - INSN_UID (insn), e->dest->index, target->index); - if (!redirect_jump (insn, block_label (target), 0)) - { - gcc_assert (target == EXIT_BLOCK_PTR); - return NULL; - } - } - - /* Cannot do anything for target exit block. */ - else if (target == EXIT_BLOCK_PTR) - return NULL; - - /* Or replace possibly complicated jump insn by simple jump insn. */ - else - { - rtx target_label = block_label (target); - rtx barrier, label, table; - - emit_jump_insn_after_noloc (gen_jump (target_label), insn); - JUMP_LABEL (BB_END (src)) = target_label; - LABEL_NUSES (target_label)++; - if (dump_file) - fprintf (dump_file, "Replacing insn %i by jump %i\n", - INSN_UID (insn), INSN_UID (BB_END (src))); - - - delete_insn_chain (kill_from, insn); - - /* Recognize a tablejump that we are converting to a - simple jump and remove its associated CODE_LABEL - and ADDR_VEC or ADDR_DIFF_VEC. */ - if (tablejump_p (insn, &label, &table)) - delete_insn_chain (label, table); - - barrier = next_nonnote_insn (BB_END (src)); - if (!barrier || !BARRIER_P (barrier)) - emit_barrier_after (BB_END (src)); - else - { - if (barrier != NEXT_INSN (BB_END (src))) - { - /* Move the jump before barrier so that the notes - which originally were or were created before jump table are - inside the basic block. */ - rtx new_insn = BB_END (src); - rtx tmp; - - for (tmp = NEXT_INSN (BB_END (src)); tmp != barrier; - tmp = NEXT_INSN (tmp)) - set_block_for_insn (tmp, src); - - NEXT_INSN (PREV_INSN (new_insn)) = NEXT_INSN (new_insn); - PREV_INSN (NEXT_INSN (new_insn)) = PREV_INSN (new_insn); - - NEXT_INSN (new_insn) = barrier; - NEXT_INSN (PREV_INSN (barrier)) = new_insn; - - PREV_INSN (new_insn) = PREV_INSN (barrier); - PREV_INSN (barrier) = new_insn; - } - } - } - - /* Keep only one edge out and set proper flags. */ - if (!single_succ_p (src)) - remove_edge (e); - gcc_assert (single_succ_p (src)); - - e = single_succ_edge (src); - if (fallthru) - e->flags = EDGE_FALLTHRU; - else - e->flags = 0; - - e->probability = REG_BR_PROB_BASE; - e->count = src->count; - - /* We don't want a block to end on a line-number note since that has - the potential of changing the code between -g and not -g. */ - while (NOTE_P (BB_END (e->src)) - && NOTE_LINE_NUMBER (BB_END (e->src)) >= 0) - delete_insn (BB_END (e->src)); - - if (e->dest != target) - redirect_edge_succ (e, target); - - return e; -} - -/* Redirect edge representing branch of (un)conditional jump or tablejump, - NULL on failure */ -static edge -redirect_branch_edge (edge e, basic_block target) -{ - rtx tmp; - rtx old_label = BB_HEAD (e->dest); - basic_block src = e->src; - rtx insn = BB_END (src); - - /* We can only redirect non-fallthru edges of jump insn. */ - if (e->flags & EDGE_FALLTHRU) - return NULL; - else if (!JUMP_P (insn)) - return NULL; - - /* Recognize a tablejump and adjust all matching cases. */ - if (tablejump_p (insn, NULL, &tmp)) - { - rtvec vec; - int j; - rtx new_label = block_label (target); - - if (target == EXIT_BLOCK_PTR) - return NULL; - if (GET_CODE (PATTERN (tmp)) == ADDR_VEC) - vec = XVEC (PATTERN (tmp), 0); - else - vec = XVEC (PATTERN (tmp), 1); - - for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) - if (XEXP (RTVEC_ELT (vec, j), 0) == old_label) - { - RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (Pmode, new_label); - --LABEL_NUSES (old_label); - ++LABEL_NUSES (new_label); - } - - /* Handle casesi dispatch insns. */ - if ((tmp = single_set (insn)) != NULL - && SET_DEST (tmp) == pc_rtx - && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE - && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF - && XEXP (XEXP (SET_SRC (tmp), 2), 0) == old_label) - { - XEXP (SET_SRC (tmp), 2) = gen_rtx_LABEL_REF (Pmode, - new_label); - --LABEL_NUSES (old_label); - ++LABEL_NUSES (new_label); - } - } - else - { - /* ?? We may play the games with moving the named labels from - one basic block to the other in case only one computed_jump is - available. */ - if (computed_jump_p (insn) - /* A return instruction can't be redirected. */ - || returnjump_p (insn)) - return NULL; - - /* If the insn doesn't go where we think, we're confused. */ - gcc_assert (JUMP_LABEL (insn) == old_label); - - /* If the substitution doesn't succeed, die. This can happen - if the back end emitted unrecognizable instructions or if - target is exit block on some arches. */ - if (!redirect_jump (insn, block_label (target), 0)) - { - gcc_assert (target == EXIT_BLOCK_PTR); - return NULL; - } - } - - if (dump_file) - fprintf (dump_file, "Edge %i->%i redirected to %i\n", - e->src->index, e->dest->index, target->index); - - if (e->dest != target) - e = redirect_edge_succ_nodup (e, target); - return e; -} - -/* Attempt to change code to redirect edge E to TARGET. Don't do that on - expense of adding new instructions or reordering basic blocks. - - Function can be also called with edge destination equivalent to the TARGET. - Then it should try the simplifications and do nothing if none is possible. - - Return edge representing the branch if transformation succeeded. Return NULL - on failure. - We still return NULL in case E already destinated TARGET and we didn't - managed to simplify instruction stream. */ - -static edge -rtl_redirect_edge_and_branch (edge e, basic_block target) -{ - edge ret; - basic_block src = e->src; - - if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) - return NULL; - - if (e->dest == target) - return e; - - if ((ret = try_redirect_by_replacing_jump (e, target, false)) != NULL) - { - src->flags |= BB_DIRTY; - return ret; - } - - ret = redirect_branch_edge (e, target); - if (!ret) - return NULL; - - src->flags |= BB_DIRTY; - return ret; -} - -/* Like force_nonfallthru below, but additionally performs redirection - Used by redirect_edge_and_branch_force. */ - -static basic_block -force_nonfallthru_and_redirect (edge e, basic_block target) -{ - basic_block jump_block, new_bb = NULL, src = e->src; - rtx note; - edge new_edge; - int abnormal_edge_flags = 0; - - /* In the case the last instruction is conditional jump to the next - instruction, first redirect the jump itself and then continue - by creating a basic block afterwards to redirect fallthru edge. */ - if (e->src != ENTRY_BLOCK_PTR && e->dest != EXIT_BLOCK_PTR - && any_condjump_p (BB_END (e->src)) - && JUMP_LABEL (BB_END (e->src)) == BB_HEAD (e->dest)) - { - rtx note; - edge b = unchecked_make_edge (e->src, target, 0); - bool redirected; - - redirected = redirect_jump (BB_END (e->src), block_label (target), 0); - gcc_assert (redirected); - - note = find_reg_note (BB_END (e->src), REG_BR_PROB, NULL_RTX); - if (note) - { - int prob = INTVAL (XEXP (note, 0)); - - b->probability = prob; - b->count = e->count * prob / REG_BR_PROB_BASE; - e->probability -= e->probability; - e->count -= b->count; - if (e->probability < 0) - e->probability = 0; - if (e->count < 0) - e->count = 0; - } - } - - if (e->flags & EDGE_ABNORMAL) - { - /* Irritating special case - fallthru edge to the same block as abnormal - edge. - We can't redirect abnormal edge, but we still can split the fallthru - one and create separate abnormal edge to original destination. - This allows bb-reorder to make such edge non-fallthru. */ - gcc_assert (e->dest == target); - abnormal_edge_flags = e->flags & ~(EDGE_FALLTHRU | EDGE_CAN_FALLTHRU); - e->flags &= EDGE_FALLTHRU | EDGE_CAN_FALLTHRU; - } - else - { - gcc_assert (e->flags & EDGE_FALLTHRU); - if (e->src == ENTRY_BLOCK_PTR) - { - /* We can't redirect the entry block. Create an empty block - at the start of the function which we use to add the new - jump. */ - edge tmp; - edge_iterator ei; - bool found = false; - - basic_block bb = create_basic_block (BB_HEAD (e->dest), NULL, ENTRY_BLOCK_PTR); - - /* Change the existing edge's source to be the new block, and add - a new edge from the entry block to the new block. */ - e->src = bb; - for (ei = ei_start (ENTRY_BLOCK_PTR->succs); (tmp = ei_safe_edge (ei)); ) - { - if (tmp == e) - { - VEC_unordered_remove (edge, ENTRY_BLOCK_PTR->succs, ei.index); - found = true; - break; - } - else - ei_next (&ei); - } - - gcc_assert (found); - - VEC_safe_push (edge, gc, bb->succs, e); - make_single_succ_edge (ENTRY_BLOCK_PTR, bb, EDGE_FALLTHRU); - } - } - - if (EDGE_COUNT (e->src->succs) >= 2 || abnormal_edge_flags) - { - /* Create the new structures. */ - - /* If the old block ended with a tablejump, skip its table - by searching forward from there. Otherwise start searching - forward from the last instruction of the old block. */ - if (!tablejump_p (BB_END (e->src), NULL, ¬e)) - note = BB_END (e->src); - note = NEXT_INSN (note); - - jump_block = create_basic_block (note, NULL, e->src); - jump_block->count = e->count; - jump_block->frequency = EDGE_FREQUENCY (e); - jump_block->loop_depth = target->loop_depth; - - if (target->il.rtl->global_live_at_start) - { - jump_block->il.rtl->global_live_at_start = ALLOC_REG_SET (®_obstack); - jump_block->il.rtl->global_live_at_end = ALLOC_REG_SET (®_obstack); - COPY_REG_SET (jump_block->il.rtl->global_live_at_start, - target->il.rtl->global_live_at_start); - COPY_REG_SET (jump_block->il.rtl->global_live_at_end, - target->il.rtl->global_live_at_start); - } - - /* Make sure new block ends up in correct hot/cold section. */ - - BB_COPY_PARTITION (jump_block, e->src); - if (flag_reorder_blocks_and_partition - && targetm.have_named_sections - && JUMP_P (BB_END (jump_block)) - && !any_condjump_p (BB_END (jump_block)) - && (EDGE_SUCC (jump_block, 0)->flags & EDGE_CROSSING)) - REG_NOTES (BB_END (jump_block)) = gen_rtx_EXPR_LIST (REG_CROSSING_JUMP, - NULL_RTX, - REG_NOTES - (BB_END - (jump_block))); - - /* Wire edge in. */ - new_edge = make_edge (e->src, jump_block, EDGE_FALLTHRU); - new_edge->probability = e->probability; - new_edge->count = e->count; - - /* Redirect old edge. */ - redirect_edge_pred (e, jump_block); - e->probability = REG_BR_PROB_BASE; - - new_bb = jump_block; - } - else - jump_block = e->src; - - e->flags &= ~EDGE_FALLTHRU; - if (target == EXIT_BLOCK_PTR) - { -#ifdef HAVE_return - emit_jump_insn_after_noloc (gen_return (), BB_END (jump_block)); -#else - gcc_unreachable (); -#endif - } - else - { - rtx label = block_label (target); - emit_jump_insn_after_noloc (gen_jump (label), BB_END (jump_block)); - JUMP_LABEL (BB_END (jump_block)) = label; - LABEL_NUSES (label)++; - } - - emit_barrier_after (BB_END (jump_block)); - redirect_edge_succ_nodup (e, target); - - if (abnormal_edge_flags) - make_edge (src, target, abnormal_edge_flags); - - return new_bb; -} - -/* Edge E is assumed to be fallthru edge. Emit needed jump instruction - (and possibly create new basic block) to make edge non-fallthru. - Return newly created BB or NULL if none. */ - -basic_block -force_nonfallthru (edge e) -{ - return force_nonfallthru_and_redirect (e, e->dest); -} - -/* Redirect edge even at the expense of creating new jump insn or - basic block. Return new basic block if created, NULL otherwise. - Conversion must be possible. */ - -static basic_block -rtl_redirect_edge_and_branch_force (edge e, basic_block target) -{ - if (redirect_edge_and_branch (e, target) - || e->dest == target) - return NULL; - - /* In case the edge redirection failed, try to force it to be non-fallthru - and redirect newly created simplejump. */ - e->src->flags |= BB_DIRTY; - return force_nonfallthru_and_redirect (e, target); -} - -/* The given edge should potentially be a fallthru edge. If that is in - fact true, delete the jump and barriers that are in the way. */ - -static void -rtl_tidy_fallthru_edge (edge e) -{ - rtx q; - basic_block b = e->src, c = b->next_bb; - - /* ??? In a late-running flow pass, other folks may have deleted basic - blocks by nopping out blocks, leaving multiple BARRIERs between here - and the target label. They ought to be chastised and fixed. - - We can also wind up with a sequence of undeletable labels between - one block and the next. - - So search through a sequence of barriers, labels, and notes for - the head of block C and assert that we really do fall through. */ - - for (q = NEXT_INSN (BB_END (b)); q != BB_HEAD (c); q = NEXT_INSN (q)) - if (INSN_P (q)) - return; - - /* Remove what will soon cease being the jump insn from the source block. - If block B consisted only of this single jump, turn it into a deleted - note. */ - q = BB_END (b); - if (JUMP_P (q) - && onlyjump_p (q) - && (any_uncondjump_p (q) - || single_succ_p (b))) - { -#ifdef HAVE_cc0 - /* If this was a conditional jump, we need to also delete - the insn that set cc0. */ - if (any_condjump_p (q) && only_sets_cc0_p (PREV_INSN (q))) - q = PREV_INSN (q); -#endif - - q = PREV_INSN (q); - - /* We don't want a block to end on a line-number note since that has - the potential of changing the code between -g and not -g. */ - while (NOTE_P (q) && NOTE_LINE_NUMBER (q) >= 0) - q = PREV_INSN (q); - } - - /* Selectively unlink the sequence. */ - if (q != PREV_INSN (BB_HEAD (c))) - delete_insn_chain (NEXT_INSN (q), PREV_INSN (BB_HEAD (c))); - - e->flags |= EDGE_FALLTHRU; -} - -/* Should move basic block BB after basic block AFTER. NIY. */ - -static bool -rtl_move_block_after (basic_block bb ATTRIBUTE_UNUSED, - basic_block after ATTRIBUTE_UNUSED) -{ - return false; -} - -/* Split a (typically critical) edge. Return the new block. - The edge must not be abnormal. - - ??? The code generally expects to be called on critical edges. - The case of a block ending in an unconditional jump to a - block with multiple predecessors is not handled optimally. */ - -static basic_block -rtl_split_edge (edge edge_in) -{ - basic_block bb; - rtx before; - - /* Abnormal edges cannot be split. */ - gcc_assert (!(edge_in->flags & EDGE_ABNORMAL)); - - /* We are going to place the new block in front of edge destination. - Avoid existence of fallthru predecessors. */ - if ((edge_in->flags & EDGE_FALLTHRU) == 0) - { - edge e; - edge_iterator ei; - - FOR_EACH_EDGE (e, ei, edge_in->dest->preds) - if (e->flags & EDGE_FALLTHRU) - break; - - if (e) - force_nonfallthru (e); - } - - /* Create the basic block note. */ - if (edge_in->dest != EXIT_BLOCK_PTR) - before = BB_HEAD (edge_in->dest); - else - before = NULL_RTX; - - /* If this is a fall through edge to the exit block, the blocks might be - not adjacent, and the right place is the after the source. */ - if (edge_in->flags & EDGE_FALLTHRU && edge_in->dest == EXIT_BLOCK_PTR) - { - before = NEXT_INSN (BB_END (edge_in->src)); - bb = create_basic_block (before, NULL, edge_in->src); - BB_COPY_PARTITION (bb, edge_in->src); - } - else - { - bb = create_basic_block (before, NULL, edge_in->dest->prev_bb); - /* ??? Why not edge_in->dest->prev_bb here? */ - BB_COPY_PARTITION (bb, edge_in->dest); - } - - /* ??? This info is likely going to be out of date very soon. */ - if (edge_in->dest->il.rtl->global_live_at_start) - { - bb->il.rtl->global_live_at_start = ALLOC_REG_SET (®_obstack); - bb->il.rtl->global_live_at_end = ALLOC_REG_SET (®_obstack); - COPY_REG_SET (bb->il.rtl->global_live_at_start, - edge_in->dest->il.rtl->global_live_at_start); - COPY_REG_SET (bb->il.rtl->global_live_at_end, - edge_in->dest->il.rtl->global_live_at_start); - } - - make_single_succ_edge (bb, edge_in->dest, EDGE_FALLTHRU); - - /* For non-fallthru edges, we must adjust the predecessor's - jump instruction to target our new block. */ - if ((edge_in->flags & EDGE_FALLTHRU) == 0) - { - edge redirected = redirect_edge_and_branch (edge_in, bb); - gcc_assert (redirected); - } - else - redirect_edge_succ (edge_in, bb); - - return bb; -} - -/* Queue instructions for insertion on an edge between two basic blocks. - The new instructions and basic blocks (if any) will not appear in the - CFG until commit_edge_insertions is called. */ - -void -insert_insn_on_edge (rtx pattern, edge e) -{ - /* We cannot insert instructions on an abnormal critical edge. - It will be easier to find the culprit if we die now. */ - gcc_assert (!((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e))); - - if (e->insns.r == NULL_RTX) - start_sequence (); - else - push_to_sequence (e->insns.r); - - emit_insn (pattern); - - e->insns.r = get_insns (); - end_sequence (); -} - -/* Update the CFG for the instructions queued on edge E. */ - -static void -commit_one_edge_insertion (edge e, int watch_calls) -{ - rtx before = NULL_RTX, after = NULL_RTX, insns, tmp, last; - basic_block bb = NULL; - - /* Pull the insns off the edge now since the edge might go away. */ - insns = e->insns.r; - e->insns.r = NULL_RTX; - - /* Special case -- avoid inserting code between call and storing - its return value. */ - if (watch_calls && (e->flags & EDGE_FALLTHRU) - && single_pred_p (e->dest) - && e->src != ENTRY_BLOCK_PTR - && CALL_P (BB_END (e->src))) - { - rtx next = next_nonnote_insn (BB_END (e->src)); - - after = BB_HEAD (e->dest); - /* The first insn after the call may be a stack pop, skip it. */ - while (next - && keep_with_call_p (next)) - { - after = next; - next = next_nonnote_insn (next); - } - bb = e->dest; - } - if (!before && !after) - { - /* Figure out where to put these things. If the destination has - one predecessor, insert there. Except for the exit block. */ - if (single_pred_p (e->dest) && e->dest != EXIT_BLOCK_PTR) - { - bb = e->dest; - - /* Get the location correct wrt a code label, and "nice" wrt - a basic block note, and before everything else. */ - tmp = BB_HEAD (bb); - if (LABEL_P (tmp)) - tmp = NEXT_INSN (tmp); - if (NOTE_INSN_BASIC_BLOCK_P (tmp)) - tmp = NEXT_INSN (tmp); - if (tmp == BB_HEAD (bb)) - before = tmp; - else if (tmp) - after = PREV_INSN (tmp); - else - after = get_last_insn (); - } - - /* If the source has one successor and the edge is not abnormal, - insert there. Except for the entry block. */ - else if ((e->flags & EDGE_ABNORMAL) == 0 - && single_succ_p (e->src) - && e->src != ENTRY_BLOCK_PTR) - { - bb = e->src; - - /* It is possible to have a non-simple jump here. Consider a target - where some forms of unconditional jumps clobber a register. This - happens on the fr30 for example. - - We know this block has a single successor, so we can just emit - the queued insns before the jump. */ - if (JUMP_P (BB_END (bb))) - before = BB_END (bb); - else - { - /* We'd better be fallthru, or we've lost track of - what's what. */ - gcc_assert (e->flags & EDGE_FALLTHRU); - - after = BB_END (bb); - } - } - /* Otherwise we must split the edge. */ - else - { - bb = split_edge (e); - after = BB_END (bb); - - if (flag_reorder_blocks_and_partition - && targetm.have_named_sections - && e->src != ENTRY_BLOCK_PTR - && BB_PARTITION (e->src) == BB_COLD_PARTITION - && !(e->flags & EDGE_CROSSING)) - { - rtx bb_note, cur_insn; - - bb_note = NULL_RTX; - for (cur_insn = BB_HEAD (bb); cur_insn != NEXT_INSN (BB_END (bb)); - cur_insn = NEXT_INSN (cur_insn)) - if (NOTE_P (cur_insn) - && NOTE_LINE_NUMBER (cur_insn) == NOTE_INSN_BASIC_BLOCK) - { - bb_note = cur_insn; - break; - } - - if (JUMP_P (BB_END (bb)) - && !any_condjump_p (BB_END (bb)) - && (single_succ_edge (bb)->flags & EDGE_CROSSING)) - REG_NOTES (BB_END (bb)) = gen_rtx_EXPR_LIST - (REG_CROSSING_JUMP, NULL_RTX, REG_NOTES (BB_END (bb))); - } - } - } - - /* Now that we've found the spot, do the insertion. */ - - if (before) - { - emit_insn_before_noloc (insns, before); - last = prev_nonnote_insn (before); - } - else - last = emit_insn_after_noloc (insns, after); - - if (returnjump_p (last)) - { - /* ??? Remove all outgoing edges from BB and add one for EXIT. - This is not currently a problem because this only happens - for the (single) epilogue, which already has a fallthru edge - to EXIT. */ - - e = single_succ_edge (bb); - gcc_assert (e->dest == EXIT_BLOCK_PTR - && single_succ_p (bb) && (e->flags & EDGE_FALLTHRU)); - - e->flags &= ~EDGE_FALLTHRU; - emit_barrier_after (last); - - if (before) - delete_insn (before); - } - else - gcc_assert (!JUMP_P (last)); - - /* Mark the basic block for find_many_sub_basic_blocks. */ - bb->aux = &bb->aux; -} - -/* Update the CFG for all queued instructions. */ - -void -commit_edge_insertions (void) -{ - basic_block bb; - sbitmap blocks; - bool changed = false; - -#ifdef ENABLE_CHECKING - verify_flow_info (); -#endif - - FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) - { - edge e; - edge_iterator ei; - - FOR_EACH_EDGE (e, ei, bb->succs) - if (e->insns.r) - { - changed = true; - commit_one_edge_insertion (e, false); - } - } - - if (!changed) - return; - - blocks = sbitmap_alloc (last_basic_block); - sbitmap_zero (blocks); - FOR_EACH_BB (bb) - if (bb->aux) - { - SET_BIT (blocks, bb->index); - /* Check for forgotten bb->aux values before commit_edge_insertions - call. */ - gcc_assert (bb->aux == &bb->aux); - bb->aux = NULL; - } - find_many_sub_basic_blocks (blocks); - sbitmap_free (blocks); -} - -/* Update the CFG for all queued instructions, taking special care of inserting - code on edges between call and storing its return value. */ - -void -commit_edge_insertions_watch_calls (void) -{ - basic_block bb; - sbitmap blocks; - bool changed = false; - -#ifdef ENABLE_CHECKING - verify_flow_info (); -#endif - - FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) - { - edge e; - edge_iterator ei; - - FOR_EACH_EDGE (e, ei, bb->succs) - if (e->insns.r) - { - changed = true; - commit_one_edge_insertion (e, true); - } - } - - if (!changed) - return; - - blocks = sbitmap_alloc (last_basic_block); - sbitmap_zero (blocks); - FOR_EACH_BB (bb) - if (bb->aux) - { - SET_BIT (blocks, bb->index); - /* Check for forgotten bb->aux values before commit_edge_insertions - call. */ - gcc_assert (bb->aux == &bb->aux); - bb->aux = NULL; - } - find_many_sub_basic_blocks (blocks); - sbitmap_free (blocks); -} - -/* Print out RTL-specific basic block information (live information - at start and end). */ - -static void -rtl_dump_bb (basic_block bb, FILE *outf, int indent) -{ - rtx insn; - rtx last; - char *s_indent; - - s_indent = alloca ((size_t) indent + 1); - memset (s_indent, ' ', (size_t) indent); - s_indent[indent] = '\0'; - - fprintf (outf, ";;%s Registers live at start: ", s_indent); - dump_regset (bb->il.rtl->global_live_at_start, outf); - putc ('\n', outf); - - for (insn = BB_HEAD (bb), last = NEXT_INSN (BB_END (bb)); insn != last; - insn = NEXT_INSN (insn)) - print_rtl_single (outf, insn); - - fprintf (outf, ";;%s Registers live at end: ", s_indent); - dump_regset (bb->il.rtl->global_live_at_end, outf); - putc ('\n', outf); -} - -/* Like print_rtl, but also print out live information for the start of each - basic block. */ - -void -print_rtl_with_bb (FILE *outf, rtx rtx_first) -{ - rtx tmp_rtx; - - if (rtx_first == 0) - fprintf (outf, "(nil)\n"); - else - { - enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB }; - int max_uid = get_max_uid (); - basic_block *start = XCNEWVEC (basic_block, max_uid); - basic_block *end = XCNEWVEC (basic_block, max_uid); - enum bb_state *in_bb_p = XCNEWVEC (enum bb_state, max_uid); - - basic_block bb; - - FOR_EACH_BB_REVERSE (bb) - { - rtx x; - - start[INSN_UID (BB_HEAD (bb))] = bb; - end[INSN_UID (BB_END (bb))] = bb; - for (x = BB_HEAD (bb); x != NULL_RTX; x = NEXT_INSN (x)) - { - enum bb_state state = IN_MULTIPLE_BB; - - if (in_bb_p[INSN_UID (x)] == NOT_IN_BB) - state = IN_ONE_BB; - in_bb_p[INSN_UID (x)] = state; - - if (x == BB_END (bb)) - break; - } - } - - for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx)) - { - int did_output; - - if ((bb = start[INSN_UID (tmp_rtx)]) != NULL) - { - fprintf (outf, ";; Start of basic block %d, registers live:", - bb->index); - dump_regset (bb->il.rtl->global_live_at_start, outf); - putc ('\n', outf); - } - - if (in_bb_p[INSN_UID (tmp_rtx)] == NOT_IN_BB - && !NOTE_P (tmp_rtx) - && !BARRIER_P (tmp_rtx)) - fprintf (outf, ";; Insn is not within a basic block\n"); - else if (in_bb_p[INSN_UID (tmp_rtx)] == IN_MULTIPLE_BB) - fprintf (outf, ";; Insn is in multiple basic blocks\n"); - - did_output = print_rtl_single (outf, tmp_rtx); - - if ((bb = end[INSN_UID (tmp_rtx)]) != NULL) - { - fprintf (outf, ";; End of basic block %d, registers live:\n", - bb->index); - dump_regset (bb->il.rtl->global_live_at_end, outf); - putc ('\n', outf); - } - - if (did_output) - putc ('\n', outf); - } - - free (start); - free (end); - free (in_bb_p); - } - - if (current_function_epilogue_delay_list != 0) - { - fprintf (outf, "\n;; Insns in epilogue delay list:\n\n"); - for (tmp_rtx = current_function_epilogue_delay_list; tmp_rtx != 0; - tmp_rtx = XEXP (tmp_rtx, 1)) - print_rtl_single (outf, XEXP (tmp_rtx, 0)); - } -} - -void -update_br_prob_note (basic_block bb) -{ - rtx note; - if (!JUMP_P (BB_END (bb))) - return; - note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX); - if (!note || INTVAL (XEXP (note, 0)) == BRANCH_EDGE (bb)->probability) - return; - XEXP (note, 0) = GEN_INT (BRANCH_EDGE (bb)->probability); -} - -/* Get the last insn associated with block BB (that includes barriers and - tablejumps after BB). */ -rtx -get_last_bb_insn (basic_block bb) -{ - rtx tmp; - rtx end = BB_END (bb); - - /* Include any jump table following the basic block. */ - if (tablejump_p (end, NULL, &tmp)) - end = tmp; - - /* Include any barriers that may follow the basic block. */ - tmp = next_nonnote_insn (end); - while (tmp && BARRIER_P (tmp)) - { - end = tmp; - tmp = next_nonnote_insn (end); - } - - return end; -} - -/* Verify the CFG and RTL consistency common for both underlying RTL and - cfglayout RTL. - - Currently it does following checks: - - - test head/end pointers - - overlapping of basic blocks - - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note) - - tails of basic blocks (ensure that boundary is necessary) - - scans body of the basic block for JUMP_INSN, CODE_LABEL - and NOTE_INSN_BASIC_BLOCK - - verify that no fall_thru edge crosses hot/cold partition boundaries - - In future it can be extended check a lot of other stuff as well - (reachability of basic blocks, life information, etc. etc.). */ - -static int -rtl_verify_flow_info_1 (void) -{ - const int max_uid = get_max_uid (); - rtx last_head = get_last_insn (); - basic_block *bb_info; - rtx x; - int err = 0; - basic_block bb; - - bb_info = XCNEWVEC (basic_block, max_uid); - - FOR_EACH_BB_REVERSE (bb) - { - rtx head = BB_HEAD (bb); - rtx end = BB_END (bb); - - /* Verify the end of the basic block is in the INSN chain. */ - for (x = last_head; x != NULL_RTX; x = PREV_INSN (x)) - if (x == end) - break; - - if (!(bb->flags & BB_RTL)) - { - error ("BB_RTL flag not set for block %d", bb->index); - err = 1; - } - - if (!x) - { - error ("end insn %d for block %d not found in the insn stream", - INSN_UID (end), bb->index); - err = 1; - } - - /* Work backwards from the end to the head of the basic block - to verify the head is in the RTL chain. */ - for (; x != NULL_RTX; x = PREV_INSN (x)) - { - /* While walking over the insn chain, verify insns appear - in only one basic block and initialize the BB_INFO array - used by other passes. */ - if (bb_info[INSN_UID (x)] != NULL) - { - error ("insn %d is in multiple basic blocks (%d and %d)", - INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index); - err = 1; - } - - bb_info[INSN_UID (x)] = bb; - - if (x == head) - break; - } - if (!x) - { - error ("head insn %d for block %d not found in the insn stream", - INSN_UID (head), bb->index); - err = 1; - } - - last_head = x; - } - - /* Now check the basic blocks (boundaries etc.) */ - FOR_EACH_BB_REVERSE (bb) - { - int n_fallthru = 0, n_eh = 0, n_call = 0, n_abnormal = 0, n_branch = 0; - edge e, fallthru = NULL; - rtx note; - edge_iterator ei; - - if (JUMP_P (BB_END (bb)) - && (note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX)) - && EDGE_COUNT (bb->succs) >= 2 - && any_condjump_p (BB_END (bb))) - { - if (INTVAL (XEXP (note, 0)) != BRANCH_EDGE (bb)->probability - && profile_status != PROFILE_ABSENT) - { - error ("verify_flow_info: REG_BR_PROB does not match cfg %wi %i", - INTVAL (XEXP (note, 0)), BRANCH_EDGE (bb)->probability); - err = 1; - } - } - FOR_EACH_EDGE (e, ei, bb->succs) - { - if (e->flags & EDGE_FALLTHRU) - { - n_fallthru++, fallthru = e; - if ((e->flags & EDGE_CROSSING) - || (BB_PARTITION (e->src) != BB_PARTITION (e->dest) - && e->src != ENTRY_BLOCK_PTR - && e->dest != EXIT_BLOCK_PTR)) - { - error ("fallthru edge crosses section boundary (bb %i)", - e->src->index); - err = 1; - } - } - - if ((e->flags & ~(EDGE_DFS_BACK - | EDGE_CAN_FALLTHRU - | EDGE_IRREDUCIBLE_LOOP - | EDGE_LOOP_EXIT - | EDGE_CROSSING)) == 0) - n_branch++; - - if (e->flags & EDGE_ABNORMAL_CALL) - n_call++; - - if (e->flags & EDGE_EH) - n_eh++; - else if (e->flags & EDGE_ABNORMAL) - n_abnormal++; - } - - if (n_eh && GET_CODE (PATTERN (BB_END (bb))) != RESX - && !find_reg_note (BB_END (bb), REG_EH_REGION, NULL_RTX)) - { - error ("missing REG_EH_REGION note in the end of bb %i", bb->index); - err = 1; - } - if (n_branch - && (!JUMP_P (BB_END (bb)) - || (n_branch > 1 && (any_uncondjump_p (BB_END (bb)) - || any_condjump_p (BB_END (bb)))))) - { - error ("too many outgoing branch edges from bb %i", bb->index); - err = 1; - } - if (n_fallthru && any_uncondjump_p (BB_END (bb))) - { - error ("fallthru edge after unconditional jump %i", bb->index); - err = 1; - } - if (n_branch != 1 && any_uncondjump_p (BB_END (bb))) - { - error ("wrong amount of branch edges after unconditional jump %i", bb->index); - err = 1; - } - if (n_branch != 1 && any_condjump_p (BB_END (bb)) - && JUMP_LABEL (BB_END (bb)) != BB_HEAD (fallthru->dest)) - { - error ("wrong amount of branch edges after conditional jump %i", - bb->index); - err = 1; - } - if (n_call && !CALL_P (BB_END (bb))) - { - error ("call edges for non-call insn in bb %i", bb->index); - err = 1; - } - if (n_abnormal - && (!CALL_P (BB_END (bb)) && n_call != n_abnormal) - && (!JUMP_P (BB_END (bb)) - || any_condjump_p (BB_END (bb)) - || any_uncondjump_p (BB_END (bb)))) - { - error ("abnormal edges for no purpose in bb %i", bb->index); - err = 1; - } - - for (x = BB_HEAD (bb); x != NEXT_INSN (BB_END (bb)); x = NEXT_INSN (x)) - /* We may have a barrier inside a basic block before dead code - elimination. There is no BLOCK_FOR_INSN field in a barrier. */ - if (!BARRIER_P (x) && BLOCK_FOR_INSN (x) != bb) - { - debug_rtx (x); - if (! BLOCK_FOR_INSN (x)) - error - ("insn %d inside basic block %d but block_for_insn is NULL", - INSN_UID (x), bb->index); - else - error - ("insn %d inside basic block %d but block_for_insn is %i", - INSN_UID (x), bb->index, BLOCK_FOR_INSN (x)->index); - - err = 1; - } - - /* OK pointers are correct. Now check the header of basic - block. It ought to contain optional CODE_LABEL followed - by NOTE_BASIC_BLOCK. */ - x = BB_HEAD (bb); - if (LABEL_P (x)) - { - if (BB_END (bb) == x) - { - error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", - bb->index); - err = 1; - } - - x = NEXT_INSN (x); - } - - if (!NOTE_INSN_BASIC_BLOCK_P (x) || NOTE_BASIC_BLOCK (x) != bb) - { - error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", - bb->index); - err = 1; - } - - if (BB_END (bb) == x) - /* Do checks for empty blocks here. */ - ; - else - for (x = NEXT_INSN (x); x; x = NEXT_INSN (x)) - { - if (NOTE_INSN_BASIC_BLOCK_P (x)) - { - error ("NOTE_INSN_BASIC_BLOCK %d in middle of basic block %d", - INSN_UID (x), bb->index); - err = 1; - } - - if (x == BB_END (bb)) - break; - - if (control_flow_insn_p (x)) - { - error ("in basic block %d:", bb->index); - fatal_insn ("flow control insn inside a basic block", x); - } - } - } - - /* Clean up. */ - free (bb_info); - return err; -} - -/* Verify the CFG and RTL consistency common for both underlying RTL and - cfglayout RTL. - - Currently it does following checks: - - all checks of rtl_verify_flow_info_1 - - check that all insns are in the basic blocks - (except the switch handling code, barriers and notes) - - check that all returns are followed by barriers - - check that all fallthru edge points to the adjacent blocks. */ -static int -rtl_verify_flow_info (void) -{ - basic_block bb; - int err = rtl_verify_flow_info_1 (); - rtx x; - int num_bb_notes; - const rtx rtx_first = get_insns (); - basic_block last_bb_seen = ENTRY_BLOCK_PTR, curr_bb = NULL; - - FOR_EACH_BB_REVERSE (bb) - { - edge e; - edge_iterator ei; - - if (bb->predictions) - { - error ("bb prediction set for block %i, but it is not used in RTL land", bb->index); - err = 1; - } - - FOR_EACH_EDGE (e, ei, bb->succs) - if (e->flags & EDGE_FALLTHRU) - break; - if (!e) - { - rtx insn; - - /* Ensure existence of barrier in BB with no fallthru edges. */ - for (insn = BB_END (bb); !insn || !BARRIER_P (insn); - insn = NEXT_INSN (insn)) - if (!insn - || (NOTE_P (insn) - && NOTE_LINE_NUMBER (insn) == NOTE_INSN_BASIC_BLOCK)) - { - error ("missing barrier after block %i", bb->index); - err = 1; - break; - } - } - else if (e->src != ENTRY_BLOCK_PTR - && e->dest != EXIT_BLOCK_PTR) - { - rtx insn; - - if (e->src->next_bb != e->dest) - { - error - ("verify_flow_info: Incorrect blocks for fallthru %i->%i", - e->src->index, e->dest->index); - err = 1; - } - else - for (insn = NEXT_INSN (BB_END (e->src)); insn != BB_HEAD (e->dest); - insn = NEXT_INSN (insn)) - if (BARRIER_P (insn) || INSN_P (insn)) - { - error ("verify_flow_info: Incorrect fallthru %i->%i", - e->src->index, e->dest->index); - fatal_insn ("wrong insn in the fallthru edge", insn); - err = 1; - } - } - } - - num_bb_notes = 0; - last_bb_seen = ENTRY_BLOCK_PTR; - - for (x = rtx_first; x; x = NEXT_INSN (x)) - { - if (NOTE_INSN_BASIC_BLOCK_P (x)) - { - bb = NOTE_BASIC_BLOCK (x); - - num_bb_notes++; - if (bb != last_bb_seen->next_bb) - internal_error ("basic blocks not laid down consecutively"); - - curr_bb = last_bb_seen = bb; - } - - if (!curr_bb) - { - switch (GET_CODE (x)) - { - case BARRIER: - case NOTE: - break; - - case CODE_LABEL: - /* An addr_vec is placed outside any basic block. */ - if (NEXT_INSN (x) - && JUMP_P (NEXT_INSN (x)) - && (GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_DIFF_VEC - || GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_VEC)) - x = NEXT_INSN (x); - - /* But in any case, non-deletable labels can appear anywhere. */ - break; - - default: - fatal_insn ("insn outside basic block", x); - } - } - - if (JUMP_P (x) - && returnjump_p (x) && ! condjump_p (x) - && ! (NEXT_INSN (x) && BARRIER_P (NEXT_INSN (x)))) - fatal_insn ("return not followed by barrier", x); - if (curr_bb && x == BB_END (curr_bb)) - curr_bb = NULL; - } - - if (num_bb_notes != n_basic_blocks - NUM_FIXED_BLOCKS) - internal_error - ("number of bb notes in insn chain (%d) != n_basic_blocks (%d)", - num_bb_notes, n_basic_blocks); - - return err; -} - -/* Assume that the preceding pass has possibly eliminated jump instructions - or converted the unconditional jumps. Eliminate the edges from CFG. - Return true if any edges are eliminated. */ - -bool -purge_dead_edges (basic_block bb) -{ - edge e; - rtx insn = BB_END (bb), note; - bool purged = false; - bool found; - edge_iterator ei; - - /* If this instruction cannot trap, remove REG_EH_REGION notes. */ - if (NONJUMP_INSN_P (insn) - && (note = find_reg_note (insn, REG_EH_REGION, NULL))) - { - rtx eqnote; - - if (! may_trap_p (PATTERN (insn)) - || ((eqnote = find_reg_equal_equiv_note (insn)) - && ! may_trap_p (XEXP (eqnote, 0)))) - remove_note (insn, note); - } - - /* Cleanup abnormal edges caused by exceptions or non-local gotos. */ - for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) - { - /* There are three types of edges we need to handle correctly here: EH - edges, abnormal call EH edges, and abnormal call non-EH edges. The - latter can appear when nonlocal gotos are used. */ - if (e->flags & EDGE_EH) - { - if (can_throw_internal (BB_END (bb)) - /* If this is a call edge, verify that this is a call insn. */ - && (! (e->flags & EDGE_ABNORMAL_CALL) - || CALL_P (BB_END (bb)))) - { - ei_next (&ei); - continue; - } - } - else if (e->flags & EDGE_ABNORMAL_CALL) - { - if (CALL_P (BB_END (bb)) - && (! (note = find_reg_note (insn, REG_EH_REGION, NULL)) - || INTVAL (XEXP (note, 0)) >= 0)) - { - ei_next (&ei); - continue; - } - } - else - { - ei_next (&ei); - continue; - } - - remove_edge (e); - bb->flags |= BB_DIRTY; - purged = true; - } - - if (JUMP_P (insn)) - { - rtx note; - edge b,f; - edge_iterator ei; - - /* We do care only about conditional jumps and simplejumps. */ - if (!any_condjump_p (insn) - && !returnjump_p (insn) - && !simplejump_p (insn)) - return purged; - - /* Branch probability/prediction notes are defined only for - condjumps. We've possibly turned condjump into simplejump. */ - if (simplejump_p (insn)) - { - note = find_reg_note (insn, REG_BR_PROB, NULL); - if (note) - remove_note (insn, note); - while ((note = find_reg_note (insn, REG_BR_PRED, NULL))) - remove_note (insn, note); - } - - for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) - { - /* Avoid abnormal flags to leak from computed jumps turned - into simplejumps. */ - - e->flags &= ~EDGE_ABNORMAL; - - /* See if this edge is one we should keep. */ - if ((e->flags & EDGE_FALLTHRU) && any_condjump_p (insn)) - /* A conditional jump can fall through into the next - block, so we should keep the edge. */ - { - ei_next (&ei); - continue; - } - else if (e->dest != EXIT_BLOCK_PTR - && BB_HEAD (e->dest) == JUMP_LABEL (insn)) - /* If the destination block is the target of the jump, - keep the edge. */ - { - ei_next (&ei); - continue; - } - else if (e->dest == EXIT_BLOCK_PTR && returnjump_p (insn)) - /* If the destination block is the exit block, and this - instruction is a return, then keep the edge. */ - { - ei_next (&ei); - continue; - } - else if ((e->flags & EDGE_EH) && can_throw_internal (insn)) - /* Keep the edges that correspond to exceptions thrown by - this instruction and rematerialize the EDGE_ABNORMAL - flag we just cleared above. */ - { - e->flags |= EDGE_ABNORMAL; - ei_next (&ei); - continue; - } - - /* We do not need this edge. */ - bb->flags |= BB_DIRTY; - purged = true; - remove_edge (e); - } - - if (EDGE_COUNT (bb->succs) == 0 || !purged) - return purged; - - if (dump_file) - fprintf (dump_file, "Purged edges from bb %i\n", bb->index); - - if (!optimize) - return purged; - - /* Redistribute probabilities. */ - if (single_succ_p (bb)) - { - single_succ_edge (bb)->probability = REG_BR_PROB_BASE; - single_succ_edge (bb)->count = bb->count; - } - else - { - note = find_reg_note (insn, REG_BR_PROB, NULL); - if (!note) - return purged; - - b = BRANCH_EDGE (bb); - f = FALLTHRU_EDGE (bb); - b->probability = INTVAL (XEXP (note, 0)); - f->probability = REG_BR_PROB_BASE - b->probability; - b->count = bb->count * b->probability / REG_BR_PROB_BASE; - f->count = bb->count * f->probability / REG_BR_PROB_BASE; - } - - return purged; - } - else if (CALL_P (insn) && SIBLING_CALL_P (insn)) - { - /* First, there should not be any EH or ABCALL edges resulting - from non-local gotos and the like. If there were, we shouldn't - have created the sibcall in the first place. Second, there - should of course never have been a fallthru edge. */ - gcc_assert (single_succ_p (bb)); - gcc_assert (single_succ_edge (bb)->flags - == (EDGE_SIBCALL | EDGE_ABNORMAL)); - - return 0; - } - - /* If we don't see a jump insn, we don't know exactly why the block would - have been broken at this point. Look for a simple, non-fallthru edge, - as these are only created by conditional branches. If we find such an - edge we know that there used to be a jump here and can then safely - remove all non-fallthru edges. */ - found = false; - FOR_EACH_EDGE (e, ei, bb->succs) - if (! (e->flags & (EDGE_COMPLEX | EDGE_FALLTHRU))) - { - found = true; - break; - } - - if (!found) - return purged; - - /* Remove all but the fake and fallthru edges. The fake edge may be - the only successor for this block in the case of noreturn - calls. */ - for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) - { - if (!(e->flags & (EDGE_FALLTHRU | EDGE_FAKE))) - { - bb->flags |= BB_DIRTY; - remove_edge (e); - purged = true; - } - else - ei_next (&ei); - } - - gcc_assert (single_succ_p (bb)); - - single_succ_edge (bb)->probability = REG_BR_PROB_BASE; - single_succ_edge (bb)->count = bb->count; - - if (dump_file) - fprintf (dump_file, "Purged non-fallthru edges from bb %i\n", - bb->index); - return purged; -} - -/* Search all basic blocks for potentially dead edges and purge them. Return - true if some edge has been eliminated. */ - -bool -purge_all_dead_edges (void) -{ - int purged = false; - basic_block bb; - - FOR_EACH_BB (bb) - { - bool purged_here = purge_dead_edges (bb); - - purged |= purged_here; - } - - return purged; -} - -/* Same as split_block but update cfg_layout structures. */ - -static basic_block -cfg_layout_split_block (basic_block bb, void *insnp) -{ - rtx insn = insnp; - basic_block new_bb = rtl_split_block (bb, insn); - - new_bb->il.rtl->footer = bb->il.rtl->footer; - bb->il.rtl->footer = NULL; - - return new_bb; -} - - -/* Redirect Edge to DEST. */ -static edge -cfg_layout_redirect_edge_and_branch (edge e, basic_block dest) -{ - basic_block src = e->src; - edge ret; - - if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) - return NULL; - - if (e->dest == dest) - return e; - - if (e->src != ENTRY_BLOCK_PTR - && (ret = try_redirect_by_replacing_jump (e, dest, true))) - { - src->flags |= BB_DIRTY; - return ret; - } - - if (e->src == ENTRY_BLOCK_PTR - && (e->flags & EDGE_FALLTHRU) && !(e->flags & EDGE_COMPLEX)) - { - if (dump_file) - fprintf (dump_file, "Redirecting entry edge from bb %i to %i\n", - e->src->index, dest->index); - - e->src->flags |= BB_DIRTY; - redirect_edge_succ (e, dest); - return e; - } - - /* Redirect_edge_and_branch may decide to turn branch into fallthru edge - in the case the basic block appears to be in sequence. Avoid this - transformation. */ - - if (e->flags & EDGE_FALLTHRU) - { - /* Redirect any branch edges unified with the fallthru one. */ - if (JUMP_P (BB_END (src)) - && label_is_jump_target_p (BB_HEAD (e->dest), - BB_END (src))) - { - edge redirected; - - if (dump_file) - fprintf (dump_file, "Fallthru edge unified with branch " - "%i->%i redirected to %i\n", - e->src->index, e->dest->index, dest->index); - e->flags &= ~EDGE_FALLTHRU; - redirected = redirect_branch_edge (e, dest); - gcc_assert (redirected); - e->flags |= EDGE_FALLTHRU; - e->src->flags |= BB_DIRTY; - return e; - } - /* In case we are redirecting fallthru edge to the branch edge - of conditional jump, remove it. */ - if (EDGE_COUNT (src->succs) == 2) - { - /* Find the edge that is different from E. */ - edge s = EDGE_SUCC (src, EDGE_SUCC (src, 0) == e); - - if (s->dest == dest - && any_condjump_p (BB_END (src)) - && onlyjump_p (BB_END (src))) - delete_insn (BB_END (src)); - } - ret = redirect_edge_succ_nodup (e, dest); - if (dump_file) - fprintf (dump_file, "Fallthru edge %i->%i redirected to %i\n", - e->src->index, e->dest->index, dest->index); - } - else - ret = redirect_branch_edge (e, dest); - - /* We don't want simplejumps in the insn stream during cfglayout. */ - gcc_assert (!simplejump_p (BB_END (src))); - - src->flags |= BB_DIRTY; - return ret; -} - -/* Simple wrapper as we always can redirect fallthru edges. */ -static basic_block -cfg_layout_redirect_edge_and_branch_force (edge e, basic_block dest) -{ - edge redirected = cfg_layout_redirect_edge_and_branch (e, dest); - - gcc_assert (redirected); - return NULL; -} - -/* Same as delete_basic_block but update cfg_layout structures. */ - -static void -cfg_layout_delete_block (basic_block bb) -{ - rtx insn, next, prev = PREV_INSN (BB_HEAD (bb)), *to, remaints; - - if (bb->il.rtl->header) - { - next = BB_HEAD (bb); - if (prev) - NEXT_INSN (prev) = bb->il.rtl->header; - else - set_first_insn (bb->il.rtl->header); - PREV_INSN (bb->il.rtl->header) = prev; - insn = bb->il.rtl->header; - while (NEXT_INSN (insn)) - insn = NEXT_INSN (insn); - NEXT_INSN (insn) = next; - PREV_INSN (next) = insn; - } - next = NEXT_INSN (BB_END (bb)); - if (bb->il.rtl->footer) - { - insn = bb->il.rtl->footer; - while (insn) - { - if (BARRIER_P (insn)) - { - if (PREV_INSN (insn)) - NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); - else - bb->il.rtl->footer = NEXT_INSN (insn); - if (NEXT_INSN (insn)) - PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); - } - if (LABEL_P (insn)) - break; - insn = NEXT_INSN (insn); - } - if (bb->il.rtl->footer) - { - insn = BB_END (bb); - NEXT_INSN (insn) = bb->il.rtl->footer; - PREV_INSN (bb->il.rtl->footer) = insn; - while (NEXT_INSN (insn)) - insn = NEXT_INSN (insn); - NEXT_INSN (insn) = next; - if (next) - PREV_INSN (next) = insn; - else - set_last_insn (insn); - } - } - if (bb->next_bb != EXIT_BLOCK_PTR) - to = &bb->next_bb->il.rtl->header; - else - to = &cfg_layout_function_footer; - - rtl_delete_block (bb); - - if (prev) - prev = NEXT_INSN (prev); - else - prev = get_insns (); - if (next) - next = PREV_INSN (next); - else - next = get_last_insn (); - - if (next && NEXT_INSN (next) != prev) - { - remaints = unlink_insn_chain (prev, next); - insn = remaints; - while (NEXT_INSN (insn)) - insn = NEXT_INSN (insn); - NEXT_INSN (insn) = *to; - if (*to) - PREV_INSN (*to) = insn; - *to = remaints; - } -} - -/* Return true when blocks A and B can be safely merged. */ -static bool -cfg_layout_can_merge_blocks_p (basic_block a, basic_block b) -{ - /* If we are partitioning hot/cold basic blocks, we don't want to - mess up unconditional or indirect jumps that cross between hot - and cold sections. - - Basic block partitioning may result in some jumps that appear to - be optimizable (or blocks that appear to be mergeable), but which really - must be left untouched (they are required to make it safely across - partition boundaries). See the comments at the top of - bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */ - - if (BB_PARTITION (a) != BB_PARTITION (b)) - return false; - - /* There must be exactly one edge in between the blocks. */ - return (single_succ_p (a) - && single_succ (a) == b - && single_pred_p (b) == 1 - && a != b - /* Must be simple edge. */ - && !(single_succ_edge (a)->flags & EDGE_COMPLEX) - && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR - /* If the jump insn has side effects, - we can't kill the edge. */ - && (!JUMP_P (BB_END (a)) - || (reload_completed - ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a))))); -} - -/* Merge block A and B. The blocks must be mergeable. */ - -static void -cfg_layout_merge_blocks (basic_block a, basic_block b) -{ -#ifdef ENABLE_CHECKING - gcc_assert (cfg_layout_can_merge_blocks_p (a, b)); -#endif - - /* If there was a CODE_LABEL beginning B, delete it. */ - if (LABEL_P (BB_HEAD (b))) - { - /* This might have been an EH label that no longer has incoming - EH edges. Update data structures to match. */ - maybe_remove_eh_handler (BB_HEAD (b)); - - delete_insn (BB_HEAD (b)); - } - - /* We should have fallthru edge in a, or we can do dummy redirection to get - it cleaned up. */ - if (JUMP_P (BB_END (a))) - try_redirect_by_replacing_jump (EDGE_SUCC (a, 0), b, true); - gcc_assert (!JUMP_P (BB_END (a))); - - /* Possible line number notes should appear in between. */ - if (b->il.rtl->header) - { - rtx first = BB_END (a), last; - - last = emit_insn_after_noloc (b->il.rtl->header, BB_END (a)); - delete_insn_chain (NEXT_INSN (first), last); - b->il.rtl->header = NULL; - } - - /* In the case basic blocks are not adjacent, move them around. */ - if (NEXT_INSN (BB_END (a)) != BB_HEAD (b)) - { - rtx first = unlink_insn_chain (BB_HEAD (b), BB_END (b)); - - emit_insn_after_noloc (first, BB_END (a)); - /* Skip possible DELETED_LABEL insn. */ - if (!NOTE_INSN_BASIC_BLOCK_P (first)) - first = NEXT_INSN (first); - gcc_assert (NOTE_INSN_BASIC_BLOCK_P (first)); - BB_HEAD (b) = NULL; - delete_insn (first); - } - /* Otherwise just re-associate the instructions. */ - else - { - rtx insn; - - for (insn = BB_HEAD (b); - insn != NEXT_INSN (BB_END (b)); - insn = NEXT_INSN (insn)) - set_block_for_insn (insn, a); - insn = BB_HEAD (b); - /* Skip possible DELETED_LABEL insn. */ - if (!NOTE_INSN_BASIC_BLOCK_P (insn)) - insn = NEXT_INSN (insn); - gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn)); - BB_HEAD (b) = NULL; - BB_END (a) = BB_END (b); - delete_insn (insn); - } - - /* Possible tablejumps and barriers should appear after the block. */ - if (b->il.rtl->footer) - { - if (!a->il.rtl->footer) - a->il.rtl->footer = b->il.rtl->footer; - else - { - rtx last = a->il.rtl->footer; - - while (NEXT_INSN (last)) - last = NEXT_INSN (last); - NEXT_INSN (last) = b->il.rtl->footer; - PREV_INSN (b->il.rtl->footer) = last; - } - b->il.rtl->footer = NULL; - } - a->il.rtl->global_live_at_end = b->il.rtl->global_live_at_end; - - if (dump_file) - fprintf (dump_file, "Merged blocks %d and %d.\n", - a->index, b->index); -} - -/* Split edge E. */ - -static basic_block -cfg_layout_split_edge (edge e) -{ - basic_block new_bb = - create_basic_block (e->src != ENTRY_BLOCK_PTR - ? NEXT_INSN (BB_END (e->src)) : get_insns (), - NULL_RTX, e->src); - - /* ??? This info is likely going to be out of date very soon, but we must - create it to avoid getting an ICE later. */ - if (e->dest->il.rtl->global_live_at_start) - { - new_bb->il.rtl->global_live_at_start = ALLOC_REG_SET (®_obstack); - new_bb->il.rtl->global_live_at_end = ALLOC_REG_SET (®_obstack); - COPY_REG_SET (new_bb->il.rtl->global_live_at_start, - e->dest->il.rtl->global_live_at_start); - COPY_REG_SET (new_bb->il.rtl->global_live_at_end, - e->dest->il.rtl->global_live_at_start); - } - - make_edge (new_bb, e->dest, EDGE_FALLTHRU); - redirect_edge_and_branch_force (e, new_bb); - - return new_bb; -} - -/* Do postprocessing after making a forwarder block joined by edge FALLTHRU. */ - -static void -rtl_make_forwarder_block (edge fallthru ATTRIBUTE_UNUSED) -{ -} - -/* Return 1 if BB ends with a call, possibly followed by some - instructions that must stay with the call, 0 otherwise. */ - -static bool -rtl_block_ends_with_call_p (basic_block bb) -{ - rtx insn = BB_END (bb); - - while (!CALL_P (insn) - && insn != BB_HEAD (bb) - && keep_with_call_p (insn)) - insn = PREV_INSN (insn); - return (CALL_P (insn)); -} - -/* Return 1 if BB ends with a conditional branch, 0 otherwise. */ - -static bool -rtl_block_ends_with_condjump_p (basic_block bb) -{ - return any_condjump_p (BB_END (bb)); -} - -/* Return true if we need to add fake edge to exit. - Helper function for rtl_flow_call_edges_add. */ - -static bool -need_fake_edge_p (rtx insn) -{ - if (!INSN_P (insn)) - return false; - - if ((CALL_P (insn) - && !SIBLING_CALL_P (insn) - && !find_reg_note (insn, REG_NORETURN, NULL) - && !CONST_OR_PURE_CALL_P (insn))) - return true; - - return ((GET_CODE (PATTERN (insn)) == ASM_OPERANDS - && MEM_VOLATILE_P (PATTERN (insn))) - || (GET_CODE (PATTERN (insn)) == PARALLEL - && asm_noperands (insn) != -1 - && MEM_VOLATILE_P (XVECEXP (PATTERN (insn), 0, 0))) - || GET_CODE (PATTERN (insn)) == ASM_INPUT); -} - -/* Add fake edges to the function exit for any non constant and non noreturn - calls, volatile inline assembly in the bitmap of blocks specified by - BLOCKS or to the whole CFG if BLOCKS is zero. Return the number of blocks - that were split. - - The goal is to expose cases in which entering a basic block does not imply - that all subsequent instructions must be executed. */ - -static int -rtl_flow_call_edges_add (sbitmap blocks) -{ - int i; - int blocks_split = 0; - int last_bb = last_basic_block; - bool check_last_block = false; - - if (n_basic_blocks == NUM_FIXED_BLOCKS) - return 0; - - if (! blocks) - check_last_block = true; - else - check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index); - - /* In the last basic block, before epilogue generation, there will be - a fallthru edge to EXIT. Special care is required if the last insn - of the last basic block is a call because make_edge folds duplicate - edges, which would result in the fallthru edge also being marked - fake, which would result in the fallthru edge being removed by - remove_fake_edges, which would result in an invalid CFG. - - Moreover, we can't elide the outgoing fake edge, since the block - profiler needs to take this into account in order to solve the minimal - spanning tree in the case that the call doesn't return. - - Handle this by adding a dummy instruction in a new last basic block. */ - if (check_last_block) - { - basic_block bb = EXIT_BLOCK_PTR->prev_bb; - rtx insn = BB_END (bb); - - /* Back up past insns that must be kept in the same block as a call. */ - while (insn != BB_HEAD (bb) - && keep_with_call_p (insn)) - insn = PREV_INSN (insn); - - if (need_fake_edge_p (insn)) - { - edge e; - - e = find_edge (bb, EXIT_BLOCK_PTR); - if (e) - { - insert_insn_on_edge (gen_rtx_USE (VOIDmode, const0_rtx), e); - commit_edge_insertions (); - } - } - } - - /* Now add fake edges to the function exit for any non constant - calls since there is no way that we can determine if they will - return or not... */ - - for (i = NUM_FIXED_BLOCKS; i < last_bb; i++) - { - basic_block bb = BASIC_BLOCK (i); - rtx insn; - rtx prev_insn; - - if (!bb) - continue; - - if (blocks && !TEST_BIT (blocks, i)) - continue; - - for (insn = BB_END (bb); ; insn = prev_insn) - { - prev_insn = PREV_INSN (insn); - if (need_fake_edge_p (insn)) - { - edge e; - rtx split_at_insn = insn; - - /* Don't split the block between a call and an insn that should - remain in the same block as the call. */ - if (CALL_P (insn)) - while (split_at_insn != BB_END (bb) - && keep_with_call_p (NEXT_INSN (split_at_insn))) - split_at_insn = NEXT_INSN (split_at_insn); - - /* The handling above of the final block before the epilogue - should be enough to verify that there is no edge to the exit - block in CFG already. Calling make_edge in such case would - cause us to mark that edge as fake and remove it later. */ - -#ifdef ENABLE_CHECKING - if (split_at_insn == BB_END (bb)) - { - e = find_edge (bb, EXIT_BLOCK_PTR); - gcc_assert (e == NULL); - } -#endif - - /* Note that the following may create a new basic block - and renumber the existing basic blocks. */ - if (split_at_insn != BB_END (bb)) - { - e = split_block (bb, split_at_insn); - if (e) - blocks_split++; - } - - make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE); - } - - if (insn == BB_HEAD (bb)) - break; - } - } - - if (blocks_split) - verify_flow_info (); - - return blocks_split; -} - -/* Add COMP_RTX as a condition at end of COND_BB. FIRST_HEAD is - the conditional branch target, SECOND_HEAD should be the fall-thru - there is no need to handle this here the loop versioning code handles - this. the reason for SECON_HEAD is that it is needed for condition - in trees, and this should be of the same type since it is a hook. */ -static void -rtl_lv_add_condition_to_bb (basic_block first_head , - basic_block second_head ATTRIBUTE_UNUSED, - basic_block cond_bb, void *comp_rtx) -{ - rtx label, seq, jump; - rtx op0 = XEXP ((rtx)comp_rtx, 0); - rtx op1 = XEXP ((rtx)comp_rtx, 1); - enum rtx_code comp = GET_CODE ((rtx)comp_rtx); - enum machine_mode mode; - - - label = block_label (first_head); - mode = GET_MODE (op0); - if (mode == VOIDmode) - mode = GET_MODE (op1); - - start_sequence (); - op0 = force_operand (op0, NULL_RTX); - op1 = force_operand (op1, NULL_RTX); - do_compare_rtx_and_jump (op0, op1, comp, 0, - mode, NULL_RTX, NULL_RTX, label); - jump = get_last_insn (); - JUMP_LABEL (jump) = label; - LABEL_NUSES (label)++; - seq = get_insns (); - end_sequence (); - - /* Add the new cond , in the new head. */ - emit_insn_after(seq, BB_END(cond_bb)); -} - - -/* Given a block B with unconditional branch at its end, get the - store the return the branch edge and the fall-thru edge in - BRANCH_EDGE and FALLTHRU_EDGE respectively. */ -static void -rtl_extract_cond_bb_edges (basic_block b, edge *branch_edge, - edge *fallthru_edge) -{ - edge e = EDGE_SUCC (b, 0); - - if (e->flags & EDGE_FALLTHRU) - { - *fallthru_edge = e; - *branch_edge = EDGE_SUCC (b, 1); - } - else - { - *branch_edge = e; - *fallthru_edge = EDGE_SUCC (b, 1); - } -} - -void -init_rtl_bb_info (basic_block bb) -{ - gcc_assert (!bb->il.rtl); - bb->il.rtl = ggc_alloc_cleared (sizeof (struct rtl_bb_info)); -} - - -/* Add EXPR to the end of basic block BB. */ - -rtx -insert_insn_end_bb_new (rtx pat, basic_block bb) -{ - rtx insn = BB_END (bb); - rtx new_insn; - rtx pat_end = pat; - - while (NEXT_INSN (pat_end) != NULL_RTX) - pat_end = NEXT_INSN (pat_end); - - /* If the last insn is a jump, insert EXPR in front [taking care to - handle cc0, etc. properly]. Similarly we need to care trapping - instructions in presence of non-call exceptions. */ - - if (JUMP_P (insn) - || (NONJUMP_INSN_P (insn) - && (!single_succ_p (bb) - || single_succ_edge (bb)->flags & EDGE_ABNORMAL))) - { -#ifdef HAVE_cc0 - rtx note; -#endif - /* If this is a jump table, then we can't insert stuff here. Since - we know the previous real insn must be the tablejump, we insert - the new instruction just before the tablejump. */ - if (GET_CODE (PATTERN (insn)) == ADDR_VEC - || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC) - insn = prev_real_insn (insn); - -#ifdef HAVE_cc0 - /* FIXME: 'twould be nice to call prev_cc0_setter here but it aborts - if cc0 isn't set. */ - note = find_reg_note (insn, REG_CC_SETTER, NULL_RTX); - if (note) - insn = XEXP (note, 0); - else - { - rtx maybe_cc0_setter = prev_nonnote_insn (insn); - if (maybe_cc0_setter - && INSN_P (maybe_cc0_setter) - && sets_cc0_p (PATTERN (maybe_cc0_setter))) - insn = maybe_cc0_setter; - } -#endif - /* FIXME: What if something in cc0/jump uses value set in new - insn? */ - new_insn = emit_insn_before_noloc (pat, insn); - } - - /* Likewise if the last insn is a call, as will happen in the presence - of exception handling. */ - else if (CALL_P (insn) - && (!single_succ_p (bb) - || single_succ_edge (bb)->flags & EDGE_ABNORMAL)) - { - /* Keeping in mind SMALL_REGISTER_CLASSES and parameters in registers, - we search backward and place the instructions before the first - parameter is loaded. Do this for everyone for consistency and a - presumption that we'll get better code elsewhere as well. */ - - /* Since different machines initialize their parameter registers - in different orders, assume nothing. Collect the set of all - parameter registers. */ - insn = find_first_parameter_load (insn, BB_HEAD (bb)); - - /* If we found all the parameter loads, then we want to insert - before the first parameter load. - - If we did not find all the parameter loads, then we might have - stopped on the head of the block, which could be a CODE_LABEL. - If we inserted before the CODE_LABEL, then we would be putting - the insn in the wrong basic block. In that case, put the insn - after the CODE_LABEL. Also, respect NOTE_INSN_BASIC_BLOCK. */ - while (LABEL_P (insn) - || NOTE_INSN_BASIC_BLOCK_P (insn)) - insn = NEXT_INSN (insn); - - new_insn = emit_insn_before_noloc (pat, insn); - } - else - new_insn = emit_insn_after_noloc (pat, insn); - - return new_insn; -} - -/* Implementation of CFG manipulation for linearized RTL. */ -struct cfg_hooks rtl_cfg_hooks = { - "rtl", - rtl_verify_flow_info, - rtl_dump_bb, - rtl_create_basic_block, - rtl_redirect_edge_and_branch, - rtl_redirect_edge_and_branch_force, - rtl_delete_block, - rtl_split_block, - rtl_move_block_after, - rtl_can_merge_blocks, /* can_merge_blocks_p */ - rtl_merge_blocks, - rtl_predict_edge, - rtl_predicted_by_p, - NULL, /* can_duplicate_block_p */ - NULL, /* duplicate_block */ - rtl_split_edge, - rtl_make_forwarder_block, - rtl_tidy_fallthru_edge, - rtl_block_ends_with_call_p, - rtl_block_ends_with_condjump_p, - rtl_flow_call_edges_add, - NULL, /* execute_on_growing_pred */ - NULL, /* execute_on_shrinking_pred */ - NULL, /* duplicate loop for trees */ - NULL, /* lv_add_condition_to_bb */ - NULL, /* lv_adjust_loop_header_phi*/ - NULL, /* extract_cond_bb_edges */ - NULL /* flush_pending_stmts */ -}; - -/* Implementation of CFG manipulation for cfg layout RTL, where - basic block connected via fallthru edges does not have to be adjacent. - This representation will hopefully become the default one in future - version of the compiler. */ - -/* We do not want to declare these functions in a header file, since they - should only be used through the cfghooks interface, and we do not want to - move them here since it would require also moving quite a lot of related - code. */ -extern bool cfg_layout_can_duplicate_bb_p (basic_block); -extern basic_block cfg_layout_duplicate_bb (basic_block); - -struct cfg_hooks cfg_layout_rtl_cfg_hooks = { - "cfglayout mode", - rtl_verify_flow_info_1, - rtl_dump_bb, - cfg_layout_create_basic_block, - cfg_layout_redirect_edge_and_branch, - cfg_layout_redirect_edge_and_branch_force, - cfg_layout_delete_block, - cfg_layout_split_block, - rtl_move_block_after, - cfg_layout_can_merge_blocks_p, - cfg_layout_merge_blocks, - rtl_predict_edge, - rtl_predicted_by_p, - cfg_layout_can_duplicate_bb_p, - cfg_layout_duplicate_bb, - cfg_layout_split_edge, - rtl_make_forwarder_block, - NULL, - rtl_block_ends_with_call_p, - rtl_block_ends_with_condjump_p, - rtl_flow_call_edges_add, - NULL, /* execute_on_growing_pred */ - NULL, /* execute_on_shrinking_pred */ - duplicate_loop_to_header_edge, /* duplicate loop for trees */ - rtl_lv_add_condition_to_bb, /* lv_add_condition_to_bb */ - NULL, /* lv_adjust_loop_header_phi*/ - rtl_extract_cond_bb_edges, /* extract_cond_bb_edges */ - NULL /* flush_pending_stmts */ -}; |