/* 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, 2006, 2007, 2008 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 3, 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 COPYING3. If not see . */ /* This file contains low level functions to manipulate the CFG and analyze it. All other modules should not transform the data structure directly and use abstraction instead. The file is supposed to be ordered bottom-up and should not contain any code dependent on a particular intermediate language (RTL or trees). Available functionality: - Initialization/deallocation init_flow, clear_edges - Low level basic block manipulation alloc_block, expunge_block - Edge manipulation make_edge, make_single_succ_edge, cached_make_edge, remove_edge - Low level edge redirection (without updating instruction chain) redirect_edge_succ, redirect_edge_succ_nodup, redirect_edge_pred - Dumping and debugging dump_flow_info, debug_flow_info, dump_edge_info - Allocation of AUX fields for basic blocks alloc_aux_for_blocks, free_aux_for_blocks, alloc_aux_for_block - clear_bb_flags - Consistency checking verify_flow_info - Dumping and debugging print_rtl_with_bb, dump_bb, debug_bb, debug_bb_n */ #include "config.h" #include "system.h" #include "coretypes.h" #include "tm.h" #include "tree.h" #include "rtl.h" #include "hard-reg-set.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 "timevar.h" #include "tree-pass.h" #include "ggc.h" #include "hashtab.h" #include "alloc-pool.h" #include "df.h" #include "cfgloop.h" #include "tree-flow.h" /* The obstack on which the flow graph components are allocated. */ struct bitmap_obstack reg_obstack; void debug_flow_info (void); static void free_edge (edge); #define RDIV(X,Y) (((X) + (Y) / 2) / (Y)) /* Called once at initialization time. */ void init_flow (struct function *the_fun) { if (!the_fun->cfg) the_fun->cfg = GGC_CNEW (struct control_flow_graph); n_edges_for_function (the_fun) = 0; ENTRY_BLOCK_PTR_FOR_FUNCTION (the_fun) = GGC_CNEW (struct basic_block_def); ENTRY_BLOCK_PTR_FOR_FUNCTION (the_fun)->index = ENTRY_BLOCK; EXIT_BLOCK_PTR_FOR_FUNCTION (the_fun) = GGC_CNEW (struct basic_block_def); EXIT_BLOCK_PTR_FOR_FUNCTION (the_fun)->index = EXIT_BLOCK; ENTRY_BLOCK_PTR_FOR_FUNCTION (the_fun)->next_bb = EXIT_BLOCK_PTR_FOR_FUNCTION (the_fun); EXIT_BLOCK_PTR_FOR_FUNCTION (the_fun)->prev_bb = ENTRY_BLOCK_PTR_FOR_FUNCTION (the_fun); } /* Helper function for remove_edge and clear_edges. Frees edge structure without actually unlinking it from the pred/succ lists. */ static void free_edge (edge e ATTRIBUTE_UNUSED) { n_edges--; ggc_free (e); } /* Free the memory associated with the edge structures. */ void clear_edges (void) { basic_block bb; edge e; edge_iterator ei; FOR_EACH_BB (bb) { FOR_EACH_EDGE (e, ei, bb->succs) free_edge (e); VEC_truncate (edge, bb->succs, 0); VEC_truncate (edge, bb->preds, 0); } FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs) free_edge (e); VEC_truncate (edge, EXIT_BLOCK_PTR->preds, 0); VEC_truncate (edge, ENTRY_BLOCK_PTR->succs, 0); gcc_assert (!n_edges); } /* Allocate memory for basic_block. */ basic_block alloc_block (void) { basic_block bb; bb = GGC_CNEW (struct basic_block_def); return bb; } /* Link block B to chain after AFTER. */ void link_block (basic_block b, basic_block after) { b->next_bb = after->next_bb; b->prev_bb = after; after->next_bb = b; b->next_bb->prev_bb = b; } /* Unlink block B from chain. */ void unlink_block (basic_block b) { b->next_bb->prev_bb = b->prev_bb; b->prev_bb->next_bb = b->next_bb; b->prev_bb = NULL; b->next_bb = NULL; } /* Sequentially order blocks and compact the arrays. */ void compact_blocks (void) { int i; SET_BASIC_BLOCK (ENTRY_BLOCK, ENTRY_BLOCK_PTR); SET_BASIC_BLOCK (EXIT_BLOCK, EXIT_BLOCK_PTR); if (df) df_compact_blocks (); else { basic_block bb; i = NUM_FIXED_BLOCKS; FOR_EACH_BB (bb) { SET_BASIC_BLOCK (i, bb); bb->index = i; i++; } gcc_assert (i == n_basic_blocks); for (; i < last_basic_block; i++) SET_BASIC_BLOCK (i, NULL); } last_basic_block = n_basic_blocks; } /* Remove block B from the basic block array. */ void expunge_block (basic_block b) { unlink_block (b); SET_BASIC_BLOCK (b->index, NULL); n_basic_blocks--; /* We should be able to ggc_free here, but we are not. The dead SSA_NAMES are left pointing to dead statements that are pointing to dead basic blocks making garbage collector to die. We should be able to release all dead SSA_NAMES and at the same time we should clear out BB pointer of dead statements consistently. */ } /* Connect E to E->src. */ static inline void connect_src (edge e) { VEC_safe_push (edge, gc, e->src->succs, e); df_mark_solutions_dirty (); } /* Connect E to E->dest. */ static inline void connect_dest (edge e) { basic_block dest = e->dest; VEC_safe_push (edge, gc, dest->preds, e); e->dest_idx = EDGE_COUNT (dest->preds) - 1; df_mark_solutions_dirty (); } /* Disconnect edge E from E->src. */ static inline void disconnect_src (edge e) { basic_block src = e->src; edge_iterator ei; edge tmp; for (ei = ei_start (src->succs); (tmp = ei_safe_edge (ei)); ) { if (tmp == e) { VEC_unordered_remove (edge, src->succs, ei.index); return; } else ei_next (&ei); } df_mark_solutions_dirty (); gcc_unreachable (); } /* Disconnect edge E from E->dest. */ static inline void disconnect_dest (edge e) { basic_block dest = e->dest; unsigned int dest_idx = e->dest_idx; VEC_unordered_remove (edge, dest->preds, dest_idx); /* If we removed an edge in the middle of the edge vector, we need to update dest_idx of the edge that moved into the "hole". */ if (dest_idx < EDGE_COUNT (dest->preds)) EDGE_PRED (dest, dest_idx)->dest_idx = dest_idx; df_mark_solutions_dirty (); } /* Create an edge connecting SRC and DEST with flags FLAGS. Return newly created edge. Use this only if you are sure that this edge can't possibly already exist. */ edge unchecked_make_edge (basic_block src, basic_block dst, int flags) { edge e; e = GGC_CNEW (struct edge_def); n_edges++; e->src = src; e->dest = dst; e->flags = flags; connect_src (e); connect_dest (e); execute_on_growing_pred (e); return e; } /* Create an edge connecting SRC and DST with FLAGS optionally using edge cache CACHE. Return the new edge, NULL if already exist. */ edge cached_make_edge (sbitmap edge_cache, basic_block src, basic_block dst, int flags) { if (edge_cache == NULL || src == ENTRY_BLOCK_PTR || dst == EXIT_BLOCK_PTR) return make_edge (src, dst, flags); /* Does the requested edge already exist? */ if (! TEST_BIT (edge_cache, dst->index)) { /* The edge does not exist. Create one and update the cache. */ SET_BIT (edge_cache, dst->index); return unchecked_make_edge (src, dst, flags); } /* At this point, we know that the requested edge exists. Adjust flags if necessary. */ if (flags) { edge e = find_edge (src, dst); e->flags |= flags; } return NULL; } /* Create an edge connecting SRC and DEST with flags FLAGS. Return newly created edge or NULL if already exist. */ edge make_edge (basic_block src, basic_block dest, int flags) { edge e = find_edge (src, dest); /* Make sure we don't add duplicate edges. */ if (e) { e->flags |= flags; return NULL; } return unchecked_make_edge (src, dest, flags); } /* Create an edge connecting SRC to DEST and set probability by knowing that it is the single edge leaving SRC. */ edge make_single_succ_edge (basic_block src, basic_block dest, int flags) { edge e = make_edge (src, dest, flags); e->probability = REG_BR_PROB_BASE; e->count = src->count; return e; } /* This function will remove an edge from the flow graph. */ void remove_edge_raw (edge e) { remove_predictions_associated_with_edge (e); execute_on_shrinking_pred (e); disconnect_src (e); disconnect_dest (e); /* This is probably not needed, but it doesn't hurt. */ redirect_edge_var_map_clear (e); free_edge (e); } /* Redirect an edge's successor from one block to another. */ void redirect_edge_succ (edge e, basic_block new_succ) { execute_on_shrinking_pred (e); disconnect_dest (e); e->dest = new_succ; /* Reconnect the edge to the new successor block. */ connect_dest (e); execute_on_growing_pred (e); } /* Like previous but avoid possible duplicate edge. */ edge redirect_edge_succ_nodup (edge e, basic_block new_succ) { edge s; s = find_edge (e->src, new_succ); if (s && s != e) { s->flags |= e->flags; s->probability += e->probability; if (s->probability > REG_BR_PROB_BASE) s->probability = REG_BR_PROB_BASE; s->count += e->count; remove_edge (e); redirect_edge_var_map_dup (s, e); e = s; } else redirect_edge_succ (e, new_succ); return e; } /* Redirect an edge's predecessor from one block to another. */ void redirect_edge_pred (edge e, basic_block new_pred) { disconnect_src (e); e->src = new_pred; /* Reconnect the edge to the new predecessor block. */ connect_src (e); } /* Clear all basic block flags, with the exception of partitioning and setjmp_target. */ void clear_bb_flags (void) { basic_block bb; FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb) bb->flags = (BB_PARTITION (bb) | (bb->flags & (BB_DISABLE_SCHEDULE + BB_RTL + BB_NON_LOCAL_GOTO_TARGET))); } /* Check the consistency of profile information. We can't do that in verify_flow_info, as the counts may get invalid for incompletely solved graphs, later eliminating of conditionals or roundoff errors. It is still practical to have them reported for debugging of simple testcases. */ void check_bb_profile (basic_block bb, FILE * file) { edge e; int sum = 0; gcov_type lsum; edge_iterator ei; if (profile_status == PROFILE_ABSENT) return; if (bb != EXIT_BLOCK_PTR) { FOR_EACH_EDGE (e, ei, bb->succs) sum += e->probability; if (EDGE_COUNT (bb->succs) && abs (sum - REG_BR_PROB_BASE) > 100) fprintf (file, "Invalid sum of outgoing probabilities %.1f%%\n", sum * 100.0 / REG_BR_PROB_BASE); lsum = 0; FOR_EACH_EDGE (e, ei, bb->succs) lsum += e->count; if (EDGE_COUNT (bb->succs) && (lsum - bb->count > 100 || lsum - bb->count < -100)) fprintf (file, "Invalid sum of outgoing counts %i, should be %i\n", (int) lsum, (int) bb->count); } if (bb != ENTRY_BLOCK_PTR) { sum = 0; FOR_EACH_EDGE (e, ei, bb->preds) sum += EDGE_FREQUENCY (e); if (abs (sum - bb->frequency) > 100) fprintf (file, "Invalid sum of incoming frequencies %i, should be %i\n", sum, bb->frequency); lsum = 0; FOR_EACH_EDGE (e, ei, bb->preds) lsum += e->count; if (lsum - bb->count > 100 || lsum - bb->count < -100) fprintf (file, "Invalid sum of incoming counts %i, should be %i\n", (int) lsum, (int) bb->count); } } /* Write information about registers and basic blocks into FILE. This is part of making a debugging dump. */ void dump_regset (regset r, FILE *outf) { unsigned i; reg_set_iterator rsi; if (r == NULL) { fputs (" (nil)", outf); return; } EXECUTE_IF_SET_IN_REG_SET (r, 0, i, rsi) { fprintf (outf, " %d", i); if (i < FIRST_PSEUDO_REGISTER) fprintf (outf, " [%s]", reg_names[i]); } } /* Print a human-readable representation of R on the standard error stream. This function is designed to be used from within the debugger. */ void debug_regset (regset r) { dump_regset (r, stderr); putc ('\n', stderr); } /* Emit basic block information for BB. HEADER is true if the user wants the generic information and the predecessors, FOOTER is true if they want the successors. FLAGS is the dump flags of interest; TDF_DETAILS emit global register liveness information. PREFIX is put in front of every line. The output is emitted to FILE. */ void dump_bb_info (basic_block bb, bool header, bool footer, int flags, const char *prefix, FILE *file) { edge e; edge_iterator ei; if (header) { fprintf (file, "\n%sBasic block %d ", prefix, bb->index); if (bb->prev_bb) fprintf (file, ", prev %d", bb->prev_bb->index); if (bb->next_bb) fprintf (file, ", next %d", bb->next_bb->index); fprintf (file, ", loop_depth %d, count ", bb->loop_depth); fprintf (file, HOST_WIDEST_INT_PRINT_DEC, bb->count); fprintf (file, ", freq %i", bb->frequency); /* Both maybe_hot_bb_p & probably_never_executed_bb_p functions crash without cfun. */ if (cfun && maybe_hot_bb_p (bb)) fprintf (file, ", maybe hot"); if (cfun && probably_never_executed_bb_p (bb)) fprintf (file, ", probably never executed"); fprintf (file, ".\n"); fprintf (file, "%sPredecessors: ", prefix); FOR_EACH_EDGE (e, ei, bb->preds) dump_edge_info (file, e, 0); if ((flags & TDF_DETAILS) && (bb->flags & BB_RTL) && df) { fprintf (file, "\n"); df_dump_top (bb, file); } } if (footer) { fprintf (file, "\n%sSuccessors: ", prefix); FOR_EACH_EDGE (e, ei, bb->succs) dump_edge_info (file, e, 1); if ((flags & TDF_DETAILS) && (bb->flags & BB_RTL) && df) { fprintf (file, "\n"); df_dump_bottom (bb, file); } } putc ('\n', file); } /* Dump the register info to FILE. */ void dump_reg_info (FILE *file) { unsigned int i, max = max_reg_num (); if (reload_completed) return; if (reg_info_p_size < max) max = reg_info_p_size; fprintf (file, "%d registers.\n", max); for (i = FIRST_PSEUDO_REGISTER; i < max; i++) { enum reg_class rclass, altclass; if (regstat_n_sets_and_refs) fprintf (file, "\nRegister %d used %d times across %d insns", i, REG_N_REFS (i), REG_LIVE_LENGTH (i)); else if (df) fprintf (file, "\nRegister %d used %d times across %d insns", i, DF_REG_USE_COUNT (i) + DF_REG_DEF_COUNT (i), REG_LIVE_LENGTH (i)); if (REG_BASIC_BLOCK (i) >= NUM_FIXED_BLOCKS) fprintf (file, " in block %d", REG_BASIC_BLOCK (i)); if (regstat_n_sets_and_refs) fprintf (file, "; set %d time%s", REG_N_SETS (i), (REG_N_SETS (i) == 1) ? "" : "s"); else if (df) fprintf (file, "; set %d time%s", DF_REG_DEF_COUNT (i), (DF_REG_DEF_COUNT (i) == 1) ? "" : "s"); if (regno_reg_rtx[i] != NULL && REG_USERVAR_P (regno_reg_rtx[i])) fprintf (file, "; user var"); if (REG_N_DEATHS (i) != 1) fprintf (file, "; dies in %d places", REG_N_DEATHS (i)); if (REG_N_CALLS_CROSSED (i) == 1) fprintf (file, "; crosses 1 call"); else if (REG_N_CALLS_CROSSED (i)) fprintf (file, "; crosses %d calls", REG_N_CALLS_CROSSED (i)); if (REG_FREQ_CALLS_CROSSED (i)) fprintf (file, "; crosses call with %d frequency", REG_FREQ_CALLS_CROSSED (i)); if (regno_reg_rtx[i] != NULL && PSEUDO_REGNO_BYTES (i) != UNITS_PER_WORD) fprintf (file, "; %d bytes", PSEUDO_REGNO_BYTES (i)); rclass = reg_preferred_class (i); altclass = reg_alternate_class (i); if (rclass != GENERAL_REGS || altclass != ALL_REGS) { if (altclass == ALL_REGS || rclass == ALL_REGS) fprintf (file, "; pref %s", reg_class_names[(int) rclass]); else if (altclass == NO_REGS) fprintf (file, "; %s or none", reg_class_names[(int) rclass]); else fprintf (file, "; pref %s, else %s", reg_class_names[(int) rclass], reg_class_names[(int) altclass]); } if (regno_reg_rtx[i] != NULL && REG_POINTER (regno_reg_rtx[i])) fprintf (file, "; pointer"); fprintf (file, ".\n"); } } void dump_flow_info (FILE *file, int flags) { basic_block bb; /* There are no pseudo registers after reload. Don't dump them. */ if (reg_info_p_size && (flags & TDF_DETAILS) != 0) dump_reg_info (file); fprintf (file, "\n%d basic blocks, %d edges.\n", n_basic_blocks, n_edges); FOR_ALL_BB (bb) { dump_bb_info (bb, true, true, flags, "", file); check_bb_profile (bb, file); } putc ('\n', file); } void debug_flow_info (void) { dump_flow_info (stderr, TDF_DETAILS); } void dump_edge_info (FILE *file, edge e, int do_succ) { basic_block side = (do_succ ? e->dest : e->src); /* both ENTRY_BLOCK_PTR & EXIT_BLOCK_PTR depend upon cfun. */ if (cfun && side == ENTRY_BLOCK_PTR) fputs (" ENTRY", file); else if (cfun && side == EXIT_BLOCK_PTR) fputs (" EXIT", file); else fprintf (file, " %d", side->index); if (e->probability) fprintf (file, " [%.1f%%] ", e->probability * 100.0 / REG_BR_PROB_BASE); if (e->count) { fprintf (file, " count:"); fprintf (file, HOST_WIDEST_INT_PRINT_DEC, e->count); } if (e->flags) { static const char * const bitnames[] = { "fallthru", "ab", "abcall", "eh", "fake", "dfs_back", "can_fallthru", "irreducible", "sibcall", "loop_exit", "true", "false", "exec" }; int comma = 0; int i, flags = e->flags; fputs (" (", file); for (i = 0; flags; i++) if (flags & (1 << i)) { flags &= ~(1 << i); if (comma) fputc (',', file); if (i < (int) ARRAY_SIZE (bitnames)) fputs (bitnames[i], file); else fprintf (file, "%d", i); comma = 1; } fputc (')', file); } } /* Simple routines to easily allocate AUX fields of basic blocks. */ static struct obstack block_aux_obstack; static void *first_block_aux_obj = 0; static struct obstack edge_aux_obstack; static void *first_edge_aux_obj = 0; /* Allocate a memory block of SIZE as BB->aux. The obstack must be first initialized by alloc_aux_for_blocks. */ inline void alloc_aux_for_block (basic_block bb, int size) { /* Verify that aux field is clear. */ gcc_assert (!bb->aux && first_block_aux_obj); bb->aux = obstack_alloc (&block_aux_obstack, size); memset (bb->aux, 0, size); } /* Initialize the block_aux_obstack and if SIZE is nonzero, call alloc_aux_for_block for each basic block. */ void alloc_aux_for_blocks (int size) { static int initialized; if (!initialized) { gcc_obstack_init (&block_aux_obstack); initialized = 1; } else /* Check whether AUX data are still allocated. */ gcc_assert (!first_block_aux_obj); first_block_aux_obj = obstack_alloc (&block_aux_obstack, 0); if (size) { basic_block bb; FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb) alloc_aux_for_block (bb, size); } } /* Clear AUX pointers of all blocks. */ void clear_aux_for_blocks (void) { basic_block bb; FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb) bb->aux = NULL; } /* Free data allocated in block_aux_obstack and clear AUX pointers of all blocks. */ void free_aux_for_blocks (void) { gcc_assert (first_block_aux_obj); obstack_free (&block_aux_obstack, first_block_aux_obj); first_block_aux_obj = NULL; clear_aux_for_blocks (); } /* Allocate a memory edge of SIZE as BB->aux. The obstack must be first initialized by alloc_aux_for_edges. */ inline void alloc_aux_for_edge (edge e, int size) { /* Verify that aux field is clear. */ gcc_assert (!e->aux && first_edge_aux_obj); e->aux = obstack_alloc (&edge_aux_obstack, size); memset (e->aux, 0, size); } /* Initialize the edge_aux_obstack and if SIZE is nonzero, call alloc_aux_for_edge for each basic edge. */ void alloc_aux_for_edges (int size) { static int initialized; if (!initialized) { gcc_obstack_init (&edge_aux_obstack); initialized = 1; } else /* Check whether AUX data are still allocated. */ gcc_assert (!first_edge_aux_obj); first_edge_aux_obj = obstack_alloc (&edge_aux_obstack, 0); if (size) { basic_block bb; FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) { edge e; edge_iterator ei; FOR_EACH_EDGE (e, ei, bb->succs) alloc_aux_for_edge (e, size); } } } /* Clear AUX pointers of all edges. */ void clear_aux_for_edges (void) { basic_block bb; edge e; FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) { edge_iterator ei; FOR_EACH_EDGE (e, ei, bb->succs) e->aux = NULL; } } /* Free data allocated in edge_aux_obstack and clear AUX pointers of all edges. */ void free_aux_for_edges (void) { gcc_assert (first_edge_aux_obj); obstack_free (&edge_aux_obstack, first_edge_aux_obj); first_edge_aux_obj = NULL; clear_aux_for_edges (); } void debug_bb (basic_block bb) { dump_bb (bb, stderr, 0); } basic_block debug_bb_n (int n) { basic_block bb = BASIC_BLOCK (n); dump_bb (bb, stderr, 0); return bb; } /* Dumps cfg related information about basic block BB to FILE. */ static void dump_cfg_bb_info (FILE *file, basic_block bb) { unsigned i; edge_iterator ei; bool first = true; static const char * const bb_bitnames[] = { "new", "reachable", "irreducible_loop", "superblock", "nosched", "hot", "cold", "dup", "xlabel", "rtl", "fwdr", "nothrd" }; const unsigned n_bitnames = sizeof (bb_bitnames) / sizeof (char *); edge e; fprintf (file, "Basic block %d", bb->index); for (i = 0; i < n_bitnames; i++) if (bb->flags & (1 << i)) { if (first) fprintf (file, " ("); else fprintf (file, ", "); first = false; fprintf (file, bb_bitnames[i]); } if (!first) fprintf (file, ")"); fprintf (file, "\n"); fprintf (file, "Predecessors: "); FOR_EACH_EDGE (e, ei, bb->preds) dump_edge_info (file, e, 0); fprintf (file, "\nSuccessors: "); FOR_EACH_EDGE (e, ei, bb->succs) dump_edge_info (file, e, 1); fprintf (file, "\n\n"); } /* Dumps a brief description of cfg to FILE. */ void brief_dump_cfg (FILE *file) { basic_block bb; FOR_EACH_BB (bb) { dump_cfg_bb_info (file, bb); } } /* An edge originally destinating BB of FREQUENCY and COUNT has been proved to leave the block by TAKEN_EDGE. Update profile of BB such that edge E can be redirected to destination of TAKEN_EDGE. This function may leave the profile inconsistent in the case TAKEN_EDGE frequency or count is believed to be lower than FREQUENCY or COUNT respectively. */ void update_bb_profile_for_threading (basic_block bb, int edge_frequency, gcov_type count, edge taken_edge) { edge c; int prob; edge_iterator ei; bb->count -= count; if (bb->count < 0) { if (dump_file) fprintf (dump_file, "bb %i count became negative after threading", bb->index); bb->count = 0; } /* Compute the probability of TAKEN_EDGE being reached via threaded edge. Watch for overflows. */ if (bb->frequency) prob = edge_frequency * REG_BR_PROB_BASE / bb->frequency; else prob = 0; if (prob > taken_edge->probability) { if (dump_file) fprintf (dump_file, "Jump threading proved probability of edge " "%i->%i too small (it is %i, should be %i).\n", taken_edge->src->index, taken_edge->dest->index, taken_edge->probability, prob); prob = taken_edge->probability; } /* Now rescale the probabilities. */ taken_edge->probability -= prob; prob = REG_BR_PROB_BASE - prob; bb->frequency -= edge_frequency; if (bb->frequency < 0) bb->frequency = 0; if (prob <= 0) { if (dump_file) fprintf (dump_file, "Edge frequencies of bb %i has been reset, " "frequency of block should end up being 0, it is %i\n", bb->index, bb->frequency); EDGE_SUCC (bb, 0)->probability = REG_BR_PROB_BASE; ei = ei_start (bb->succs); ei_next (&ei); for (; (c = ei_safe_edge (ei)); ei_next (&ei)) c->probability = 0; } else if (prob != REG_BR_PROB_BASE) { int scale = RDIV (65536 * REG_BR_PROB_BASE, prob); FOR_EACH_EDGE (c, ei, bb->succs) { /* Protect from overflow due to additional scaling. */ if (c->probability > prob) c->probability = REG_BR_PROB_BASE; else { c->probability = RDIV (c->probability * scale, 65536); if (c->probability > REG_BR_PROB_BASE) c->probability = REG_BR_PROB_BASE; } } } gcc_assert (bb == taken_edge->src); taken_edge->count -= count; if (taken_edge->count < 0) { if (dump_file) fprintf (dump_file, "edge %i->%i count became negative after threading", taken_edge->src->index, taken_edge->dest->index); taken_edge->count = 0; } } /* Multiply all frequencies of basic blocks in array BBS of length NBBS by NUM/DEN, in int arithmetic. May lose some accuracy. */ void scale_bbs_frequencies_int (basic_block *bbs, int nbbs, int num, int den) { int i; edge e; if (num < 0) num = 0; /* Scale NUM and DEN to avoid overflows. Frequencies are in order of 10^4, if we make DEN <= 10^3, we can afford to upscale by 100 and still safely fit in int during calculations. */ if (den > 1000) { if (num > 1000000) return; num = RDIV (1000.0 * num, den); den = 1000; } if (num > 100 * den) return; for (i = 0; i < nbbs; i++) { edge_iterator ei; bbs[i]->frequency = RDIV (bbs[i]->frequency * num, den); /* Make sure the frequencies do not grow over BB_FREQ_MAX. */ if (bbs[i]->frequency > BB_FREQ_MAX) bbs[i]->frequency = BB_FREQ_MAX; bbs[i]->count = RDIV ((double)bbs[i]->count * num, den); FOR_EACH_EDGE (e, ei, bbs[i]->succs) e->count = RDIV ((double)e->count * num, den); } } /* numbers smaller than this value are safe to multiply without getting 64bit overflow. */ #define MAX_SAFE_MULTIPLIER (1 << (sizeof (HOST_WIDEST_INT) * 4 - 1)) /* Multiply all frequencies of basic blocks in array BBS of length NBBS by NUM/DEN, in gcov_type arithmetic. More accurate than previous function but considerably slower. */ void scale_bbs_frequencies_gcov_type (basic_block *bbs, int nbbs, gcov_type num, gcov_type den) { int i; edge e; gcov_type fraction = RDIV (num * 65536.0, den); gcc_assert (fraction >= 0); if (num < MAX_SAFE_MULTIPLIER) for (i = 0; i < nbbs; i++) { edge_iterator ei; bbs[i]->frequency = RDIV (bbs[i]->frequency * num, den); if (bbs[i]->count <= MAX_SAFE_MULTIPLIER) bbs[i]->count = RDIV ((double)bbs[i]->count * num, den); else bbs[i]->count = RDIV ((double)bbs[i]->count * fraction, 65536); FOR_EACH_EDGE (e, ei, bbs[i]->succs) if (bbs[i]->count <= MAX_SAFE_MULTIPLIER) e->count = RDIV ((double)e->count * num, den); else e->count = RDIV ((double)e->count * fraction, 65536); } else for (i = 0; i < nbbs; i++) { edge_iterator ei; if (sizeof (gcov_type) > sizeof (int)) bbs[i]->frequency = RDIV (bbs[i]->frequency * num, den); else bbs[i]->frequency = RDIV (bbs[i]->frequency * fraction, 65536); bbs[i]->count = RDIV ((double)bbs[i]->count * fraction, 65536); FOR_EACH_EDGE (e, ei, bbs[i]->succs) e->count = RDIV ((double)e->count * fraction, 65536); } } /* Data structures used to maintain mapping between basic blocks and copies. */ static htab_t bb_original; static htab_t bb_copy; /* And between loops and copies. */ static htab_t loop_copy; static alloc_pool original_copy_bb_pool; struct htab_bb_copy_original_entry { /* Block we are attaching info to. */ int index1; /* Index of original or copy (depending on the hashtable) */ int index2; }; static hashval_t bb_copy_original_hash (const void *p) { const struct htab_bb_copy_original_entry *data = ((const struct htab_bb_copy_original_entry *)p); return data->index1; } static int bb_copy_original_eq (const void *p, const void *q) { const struct htab_bb_copy_original_entry *data = ((const struct htab_bb_copy_original_entry *)p); const struct htab_bb_copy_original_entry *data2 = ((const struct htab_bb_copy_original_entry *)q); return data->index1 == data2->index1; } /* Initialize the data structures to maintain mapping between blocks and its copies. */ void initialize_original_copy_tables (void) { gcc_assert (!original_copy_bb_pool); original_copy_bb_pool = create_alloc_pool ("original_copy", sizeof (struct htab_bb_copy_original_entry), 10); bb_original = htab_create (10, bb_copy_original_hash, bb_copy_original_eq, NULL); bb_copy = htab_create (10, bb_copy_original_hash, bb_copy_original_eq, NULL); loop_copy = htab_create (10, bb_copy_original_hash, bb_copy_original_eq, NULL); } /* Free the data structures to maintain mapping between blocks and its copies. */ void free_original_copy_tables (void) { gcc_assert (original_copy_bb_pool); htab_delete (bb_copy); htab_delete (bb_original); htab_delete (loop_copy); free_alloc_pool (original_copy_bb_pool); bb_copy = NULL; bb_original = NULL; loop_copy = NULL; original_copy_bb_pool = NULL; } /* Removes the value associated with OBJ from table TAB. */ static void copy_original_table_clear (htab_t tab, unsigned obj) { void **slot; struct htab_bb_copy_original_entry key, *elt; if (!original_copy_bb_pool) return; key.index1 = obj; slot = htab_find_slot (tab, &key, NO_INSERT); if (!slot) return; elt = (struct htab_bb_copy_original_entry *) *slot; htab_clear_slot (tab, slot); pool_free (original_copy_bb_pool, elt); } /* Sets the value associated with OBJ in table TAB to VAL. Do nothing when data structures are not initialized. */ static void copy_original_table_set (htab_t tab, unsigned obj, unsigned val) { struct htab_bb_copy_original_entry **slot; struct htab_bb_copy_original_entry key; if (!original_copy_bb_pool) return; key.index1 = obj; slot = (struct htab_bb_copy_original_entry **) htab_find_slot (tab, &key, INSERT); if (!*slot) { *slot = (struct htab_bb_copy_original_entry *) pool_alloc (original_copy_bb_pool); (*slot)->index1 = obj; } (*slot)->index2 = val; } /* Set original for basic block. Do nothing when data structures are not initialized so passes not needing this don't need to care. */ void set_bb_original (basic_block bb, basic_block original) { copy_original_table_set (bb_original, bb->index, original->index); } /* Get the original basic block. */ basic_block get_bb_original (basic_block bb) { struct htab_bb_copy_original_entry *entry; struct htab_bb_copy_original_entry key; gcc_assert (original_copy_bb_pool); key.index1 = bb->index; entry = (struct htab_bb_copy_original_entry *) htab_find (bb_original, &key); if (entry) return BASIC_BLOCK (entry->index2); else return NULL; } /* Set copy for basic block. Do nothing when data structures are not initialized so passes not needing this don't need to care. */ void set_bb_copy (basic_block bb, basic_block copy) { copy_original_table_set (bb_copy, bb->index, copy->index); } /* Get the copy of basic block. */ basic_block get_bb_copy (basic_block bb) { struct htab_bb_copy_original_entry *entry; struct htab_bb_copy_original_entry key; gcc_assert (original_copy_bb_pool); key.index1 = bb->index; entry = (struct htab_bb_copy_original_entry *) htab_find (bb_copy, &key); if (entry) return BASIC_BLOCK (entry->index2); else return NULL; } /* Set copy for LOOP to COPY. Do nothing when data structures are not initialized so passes not needing this don't need to care. */ void set_loop_copy (struct loop *loop, struct loop *copy) { if (!copy) copy_original_table_clear (loop_copy, loop->num); else copy_original_table_set (loop_copy, loop->num, copy->num); } /* Get the copy of LOOP. */ struct loop * get_loop_copy (struct loop *loop) { struct htab_bb_copy_original_entry *entry; struct htab_bb_copy_original_entry key; gcc_assert (original_copy_bb_pool); key.index1 = loop->num; entry = (struct htab_bb_copy_original_entry *) htab_find (loop_copy, &key); if (entry) return get_loop (entry->index2); else return NULL; }