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Diffstat (limited to 'gcc/cfg.c')
| -rw-r--r-- | gcc/cfg.c | 1300 |
1 files changed, 1300 insertions, 0 deletions
diff --git a/gcc/cfg.c b/gcc/cfg.c new file mode 100644 index 000000000..c8ef79914 --- /dev/null +++ b/gcc/cfg.c @@ -0,0 +1,1300 @@ +/* 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, 2009, 2010 + 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 +<http://www.gnu.org/licenses/>. */ + +/* 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 "diagnostic-core.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_alloc_cleared_control_flow_graph (); + n_edges_for_function (the_fun) = 0; + ENTRY_BLOCK_PTR_FOR_FUNCTION (the_fun) + = ggc_alloc_cleared_basic_block_def (); + ENTRY_BLOCK_PTR_FOR_FUNCTION (the_fun)->index = ENTRY_BLOCK; + EXIT_BLOCK_PTR_FOR_FUNCTION (the_fun) + = ggc_alloc_cleared_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_alloc_cleared_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_alloc_cleared_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. */ + +DEBUG_FUNCTION 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)) + fputs (", maybe hot", file); + if (cfun && probably_never_executed_bb_p (bb)) + fputs (", probably never executed", file); + fputs (".\n", file); + + 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) + { + putc ('\n', file); + 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) + { + putc ('\n', file); + 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])) + fputs ("; user var", file); + if (REG_N_DEATHS (i) != 1) + fprintf (file, "; dies in %d places", REG_N_DEATHS (i)); + if (REG_N_CALLS_CROSSED (i) == 1) + fputs ("; crosses 1 call", file); + 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])) + fputs ("; pointer", file); + fputs (".\n", file); + } +} + + +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); +} + +DEBUG_FUNCTION 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) + { + fputs (" count:", file); + 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. */ + +static 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_ALL_BB (bb) + alloc_aux_for_block (bb, size); + } +} + +/* Clear AUX pointers of all blocks. */ + +void +clear_aux_for_blocks (void) +{ + basic_block bb; + + FOR_ALL_BB (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. */ + +static 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 (); +} + +DEBUG_FUNCTION void +debug_bb (basic_block bb) +{ + dump_bb (bb, stderr, 0); +} + +DEBUG_FUNCTION 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) + fputs (" (", file); + else + fputs (", ", file); + first = false; + fputs (bb_bitnames[i], file); + } + if (!first) + putc (')', file); + putc ('\n', file); + + fputs ("Predecessors: ", file); + 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); + fputs ("\n\n", file); +} + +/* 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 * 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 (bbs[i]->count * num, den); + FOR_EACH_EDGE (e, ei, bbs[i]->succs) + e->count = RDIV (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, 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 (bbs[i]->count * num, den); + else + bbs[i]->count = RDIV (bbs[i]->count * fraction, 65536); + FOR_EACH_EDGE (e, ei, bbs[i]->succs) + if (bbs[i]->count <= MAX_SAFE_MULTIPLIER) + e->count = RDIV (e->count * num, den); + else + e->count = RDIV (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 (bbs[i]->count * fraction, 65536); + FOR_EACH_EDGE (e, ei, bbs[i]->succs) + e->count = RDIV (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; +} |