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Diffstat (limited to 'gcc-4.2.1-5666.3/gcc/ddg.c')
| -rw-r--r-- | gcc-4.2.1-5666.3/gcc/ddg.c | 1055 |
1 files changed, 0 insertions, 1055 deletions
diff --git a/gcc-4.2.1-5666.3/gcc/ddg.c b/gcc-4.2.1-5666.3/gcc/ddg.c deleted file mode 100644 index c59ee6ea8..000000000 --- a/gcc-4.2.1-5666.3/gcc/ddg.c +++ /dev/null @@ -1,1055 +0,0 @@ -/* DDG - Data Dependence Graph implementation. - Copyright (C) 2004, 2005, 2006 - Free Software Foundation, Inc. - Contributed by Ayal Zaks and Mustafa Hagog <zaks,mustafa@il.ibm.com> - -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. */ - - -#include "config.h" -#include "system.h" -#include "coretypes.h" -#include "tm.h" -#include "toplev.h" -#include "rtl.h" -#include "tm_p.h" -#include "hard-reg-set.h" -#include "regs.h" -#include "function.h" -#include "flags.h" -#include "insn-config.h" -#include "insn-attr.h" -#include "except.h" -#include "recog.h" -#include "sched-int.h" -#include "target.h" -#include "cfglayout.h" -#include "cfgloop.h" -#include "sbitmap.h" -#include "expr.h" -#include "bitmap.h" -#include "df.h" -#include "ddg.h" - -/* A flag indicating that a ddg edge belongs to an SCC or not. */ -enum edge_flag {NOT_IN_SCC = 0, IN_SCC}; - -/* Forward declarations. */ -static void add_backarc_to_ddg (ddg_ptr, ddg_edge_ptr); -static void add_backarc_to_scc (ddg_scc_ptr, ddg_edge_ptr); -static void add_scc_to_ddg (ddg_all_sccs_ptr, ddg_scc_ptr); -static void create_ddg_dependence (ddg_ptr, ddg_node_ptr, ddg_node_ptr, rtx); -static void create_ddg_dep_no_link (ddg_ptr, ddg_node_ptr, ddg_node_ptr, - dep_type, dep_data_type, int); -static ddg_edge_ptr create_ddg_edge (ddg_node_ptr, ddg_node_ptr, dep_type, - dep_data_type, int, int); -static void add_edge_to_ddg (ddg_ptr g, ddg_edge_ptr); - -/* Auxiliary variable for mem_read_insn_p/mem_write_insn_p. */ -static bool mem_ref_p; - -/* Auxiliary function for mem_read_insn_p. */ -static int -mark_mem_use (rtx *x, void *data ATTRIBUTE_UNUSED) -{ - if (MEM_P (*x)) - mem_ref_p = true; - return 0; -} - -/* Auxiliary function for mem_read_insn_p. */ -static void -mark_mem_use_1 (rtx *x, void *data) -{ - for_each_rtx (x, mark_mem_use, data); -} - -/* Returns nonzero if INSN reads from memory. */ -static bool -mem_read_insn_p (rtx insn) -{ - mem_ref_p = false; - note_uses (&PATTERN (insn), mark_mem_use_1, NULL); - return mem_ref_p; -} - -static void -mark_mem_store (rtx loc, rtx setter ATTRIBUTE_UNUSED, void *data ATTRIBUTE_UNUSED) -{ - if (MEM_P (loc)) - mem_ref_p = true; -} - -/* Returns nonzero if INSN writes to memory. */ -static bool -mem_write_insn_p (rtx insn) -{ - mem_ref_p = false; - note_stores (PATTERN (insn), mark_mem_store, NULL); - return mem_ref_p; -} - -/* Returns nonzero if X has access to memory. */ -static bool -rtx_mem_access_p (rtx x) -{ - int i, j; - const char *fmt; - enum rtx_code code; - - if (x == 0) - return false; - - if (MEM_P (x)) - return true; - - code = GET_CODE (x); - fmt = GET_RTX_FORMAT (code); - for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) - { - if (fmt[i] == 'e') - { - if (rtx_mem_access_p (XEXP (x, i))) - return true; - } - else if (fmt[i] == 'E') - for (j = 0; j < XVECLEN (x, i); j++) - { - if (rtx_mem_access_p (XVECEXP (x, i, j))) - return true; - } - } - return false; -} - -/* Returns nonzero if INSN reads to or writes from memory. */ -static bool -mem_access_insn_p (rtx insn) -{ - return rtx_mem_access_p (PATTERN (insn)); -} - -/* Computes the dependence parameters (latency, distance etc.), creates - a ddg_edge and adds it to the given DDG. */ -static void -create_ddg_dependence (ddg_ptr g, ddg_node_ptr src_node, - ddg_node_ptr dest_node, rtx link) -{ - ddg_edge_ptr e; - int latency, distance = 0; - int interloop = (src_node->cuid >= dest_node->cuid); - dep_type t = TRUE_DEP; - dep_data_type dt = (mem_access_insn_p (src_node->insn) - && mem_access_insn_p (dest_node->insn) ? MEM_DEP - : REG_DEP); - - /* For now we don't have an exact calculation of the distance, - so assume 1 conservatively. */ - if (interloop) - distance = 1; - - gcc_assert (link); - - /* Note: REG_DEP_ANTI applies to MEM ANTI_DEP as well!! */ - if (REG_NOTE_KIND (link) == REG_DEP_ANTI) - t = ANTI_DEP; - else if (REG_NOTE_KIND (link) == REG_DEP_OUTPUT) - t = OUTPUT_DEP; - latency = insn_cost (src_node->insn, link, dest_node->insn); - - e = create_ddg_edge (src_node, dest_node, t, dt, latency, distance); - - if (interloop) - { - /* Some interloop dependencies are relaxed: - 1. Every insn is output dependent on itself; ignore such deps. - 2. Every true/flow dependence is an anti dependence in the - opposite direction with distance 1; such register deps - will be removed by renaming if broken --- ignore them. */ - if (!(t == OUTPUT_DEP && src_node == dest_node) - && !(t == ANTI_DEP && dt == REG_DEP)) - add_backarc_to_ddg (g, e); - else - free (e); - } - else if (t == ANTI_DEP && dt == REG_DEP) - free (e); /* We can fix broken anti register deps using reg-moves. */ - else - add_edge_to_ddg (g, e); -} - -/* The same as the above function, but it doesn't require a link parameter. */ -static void -create_ddg_dep_no_link (ddg_ptr g, ddg_node_ptr from, ddg_node_ptr to, - dep_type d_t, dep_data_type d_dt, int distance) -{ - ddg_edge_ptr e; - int l; - rtx link = alloc_INSN_LIST (to->insn, NULL_RTX); - - if (d_t == ANTI_DEP) - PUT_REG_NOTE_KIND (link, REG_DEP_ANTI); - else if (d_t == OUTPUT_DEP) - PUT_REG_NOTE_KIND (link, REG_DEP_OUTPUT); - - l = insn_cost (from->insn, link, to->insn); - free_INSN_LIST_node (link); - - e = create_ddg_edge (from, to, d_t, d_dt, l, distance); - if (distance > 0) - add_backarc_to_ddg (g, e); - else - add_edge_to_ddg (g, e); -} - - -/* Given a downwards exposed register def RD, add inter-loop true dependences - for all its uses in the next iteration, and an output dependence to the - first def of the next iteration. */ -static void -add_deps_for_def (ddg_ptr g, struct df *df, struct df_ref *rd) -{ - int regno = DF_REF_REGNO (rd); - struct df_ru_bb_info *bb_info = DF_RU_BB_INFO (df, g->bb); - struct df_link *r_use; - int use_before_def = false; - rtx def_insn = DF_REF_INSN (rd); - ddg_node_ptr src_node = get_node_of_insn (g, def_insn); - - /* Create and inter-loop true dependence between RD and each of its uses - that is upwards exposed in RD's block. */ - for (r_use = DF_REF_CHAIN (rd); r_use != NULL; r_use = r_use->next) - { - if (bitmap_bit_p (bb_info->gen, r_use->ref->id)) - { - rtx use_insn = DF_REF_INSN (r_use->ref); - ddg_node_ptr dest_node = get_node_of_insn (g, use_insn); - - gcc_assert (src_node && dest_node); - - /* Any such upwards exposed use appears before the rd def. */ - use_before_def = true; - create_ddg_dep_no_link (g, src_node, dest_node, TRUE_DEP, - REG_DEP, 1); - } - } - - /* Create an inter-loop output dependence between RD (which is the - last def in its block, being downwards exposed) and the first def - in its block. Avoid creating a self output dependence. Avoid creating - an output dependence if there is a dependence path between the two defs - starting with a true dependence followed by an anti dependence (i.e. if - there is a use between the two defs. */ - if (! use_before_def) - { - struct df_ref *def = df_bb_regno_first_def_find (df, g->bb, regno); - int i; - ddg_node_ptr dest_node; - - if (!def || rd->id == def->id) - return; - - /* Check if there are uses after RD. */ - for (i = src_node->cuid + 1; i < g->num_nodes; i++) - if (df_find_use (df, g->nodes[i].insn, rd->reg)) - return; - - dest_node = get_node_of_insn (g, def->insn); - create_ddg_dep_no_link (g, src_node, dest_node, OUTPUT_DEP, REG_DEP, 1); - } -} - -/* Given a register USE, add an inter-loop anti dependence to the first - (nearest BLOCK_BEGIN) def of the next iteration, unless USE is followed - by a def in the block. */ -static void -add_deps_for_use (ddg_ptr g, struct df *df, struct df_ref *use) -{ - int i; - int regno = DF_REF_REGNO (use); - struct df_ref *first_def = df_bb_regno_first_def_find (df, g->bb, regno); - ddg_node_ptr use_node; - ddg_node_ptr def_node; - struct df_rd_bb_info *bb_info; - - bb_info = DF_RD_BB_INFO (df, g->bb); - - if (!first_def) - return; - - use_node = get_node_of_insn (g, use->insn); - def_node = get_node_of_insn (g, first_def->insn); - - gcc_assert (use_node && def_node); - - /* Make sure there are no defs after USE. */ - for (i = use_node->cuid + 1; i < g->num_nodes; i++) - if (df_find_def (df, g->nodes[i].insn, use->reg)) - return; - /* We must not add ANTI dep when there is an intra-loop TRUE dep in - the opposite direction. If the first_def reaches the USE then there is - such a dep. */ - if (! bitmap_bit_p (bb_info->gen, first_def->id)) - create_ddg_dep_no_link (g, use_node, def_node, ANTI_DEP, REG_DEP, 1); -} - -/* Build inter-loop dependencies, by looking at DF analysis backwards. */ -static void -build_inter_loop_deps (ddg_ptr g, struct df *df) -{ - unsigned rd_num, u_num; - struct df_rd_bb_info *rd_bb_info; - struct df_ru_bb_info *ru_bb_info; - bitmap_iterator bi; - - rd_bb_info = DF_RD_BB_INFO (df, g->bb); - - /* Find inter-loop output and true deps by connecting downward exposed defs - to the first def of the BB and to upwards exposed uses. */ - EXECUTE_IF_SET_IN_BITMAP (rd_bb_info->gen, 0, rd_num, bi) - { - struct df_ref *rd = DF_DEFS_GET (df, rd_num); - - add_deps_for_def (g, df, rd); - } - - ru_bb_info = DF_RU_BB_INFO (df, g->bb); - - /* Find inter-loop anti deps. We are interested in uses of the block that - appear below all defs; this implies that these uses are killed. */ - EXECUTE_IF_SET_IN_BITMAP (ru_bb_info->kill, 0, u_num, bi) - { - struct df_ref *use = DF_USES_GET (df, u_num); - - /* We are interested in uses of this BB. */ - if (BLOCK_FOR_INSN (use->insn) == g->bb) - add_deps_for_use (g, df, use); - } -} - -/* Given two nodes, analyze their RTL insns and add inter-loop mem deps - to ddg G. */ -static void -add_inter_loop_mem_dep (ddg_ptr g, ddg_node_ptr from, ddg_node_ptr to) -{ - if (mem_write_insn_p (from->insn)) - { - if (mem_read_insn_p (to->insn)) - create_ddg_dep_no_link (g, from, to, TRUE_DEP, MEM_DEP, 1); - else if (from->cuid != to->cuid) - create_ddg_dep_no_link (g, from, to, OUTPUT_DEP, MEM_DEP, 1); - } - else - { - if (mem_read_insn_p (to->insn)) - return; - else if (from->cuid != to->cuid) - { - create_ddg_dep_no_link (g, from, to, ANTI_DEP, MEM_DEP, 1); - create_ddg_dep_no_link (g, to, from, TRUE_DEP, MEM_DEP, 1); - } - } - -} - -/* Perform intra-block Data Dependency analysis and connect the nodes in - the DDG. We assume the loop has a single basic block. */ -static void -build_intra_loop_deps (ddg_ptr g) -{ - int i; - /* Hold the dependency analysis state during dependency calculations. */ - struct deps tmp_deps; - rtx head, tail, link; - - /* Build the dependence information, using the sched_analyze function. */ - init_deps_global (); - init_deps (&tmp_deps); - - /* Do the intra-block data dependence analysis for the given block. */ - get_ebb_head_tail (g->bb, g->bb, &head, &tail); - sched_analyze (&tmp_deps, head, tail); - - /* Build intra-loop data dependencies using the scheduler dependency - analysis. */ - for (i = 0; i < g->num_nodes; i++) - { - ddg_node_ptr dest_node = &g->nodes[i]; - - if (! INSN_P (dest_node->insn)) - continue; - - for (link = LOG_LINKS (dest_node->insn); link; link = XEXP (link, 1)) - { - ddg_node_ptr src_node = get_node_of_insn (g, XEXP (link, 0)); - - if (!src_node) - continue; - - add_forw_dep (dest_node->insn, link); - create_ddg_dependence (g, src_node, dest_node, - INSN_DEPEND (src_node->insn)); - } - - /* If this insn modifies memory, add an edge to all insns that access - memory. */ - if (mem_access_insn_p (dest_node->insn)) - { - int j; - - for (j = 0; j <= i; j++) - { - ddg_node_ptr j_node = &g->nodes[j]; - if (mem_access_insn_p (j_node->insn)) - /* Don't bother calculating inter-loop dep if an intra-loop dep - already exists. */ - if (! TEST_BIT (dest_node->successors, j)) - add_inter_loop_mem_dep (g, dest_node, j_node); - } - } - } - - /* Free the INSN_LISTs. */ - finish_deps_global (); - free_deps (&tmp_deps); -} - - -/* Given a basic block, create its DDG and return a pointer to a variable - of ddg type that represents it. - Initialize the ddg structure fields to the appropriate values. */ -ddg_ptr -create_ddg (basic_block bb, struct df *df, int closing_branch_deps) -{ - ddg_ptr g; - rtx insn, first_note; - int i; - int num_nodes = 0; - - g = (ddg_ptr) xcalloc (1, sizeof (struct ddg)); - - g->bb = bb; - g->closing_branch_deps = closing_branch_deps; - - /* Count the number of insns in the BB. */ - for (insn = BB_HEAD (bb); insn != NEXT_INSN (BB_END (bb)); - insn = NEXT_INSN (insn)) - { - if (! INSN_P (insn) || GET_CODE (PATTERN (insn)) == USE) - continue; - - if (mem_read_insn_p (insn)) - g->num_loads++; - if (mem_write_insn_p (insn)) - g->num_stores++; - num_nodes++; - } - - /* There is nothing to do for this BB. */ - if (num_nodes <= 1) - { - free (g); - return NULL; - } - - /* Allocate the nodes array, and initialize the nodes. */ - g->num_nodes = num_nodes; - g->nodes = (ddg_node_ptr) xcalloc (num_nodes, sizeof (struct ddg_node)); - g->closing_branch = NULL; - i = 0; - first_note = NULL_RTX; - for (insn = BB_HEAD (bb); insn != NEXT_INSN (BB_END (bb)); - insn = NEXT_INSN (insn)) - { - if (! INSN_P (insn)) - { - if (! first_note && NOTE_P (insn) - && NOTE_LINE_NUMBER (insn) != NOTE_INSN_BASIC_BLOCK) - first_note = insn; - continue; - } - if (JUMP_P (insn)) - { - gcc_assert (!g->closing_branch); - g->closing_branch = &g->nodes[i]; - } - else if (GET_CODE (PATTERN (insn)) == USE) - { - if (! first_note) - first_note = insn; - continue; - } - - g->nodes[i].cuid = i; - g->nodes[i].successors = sbitmap_alloc (num_nodes); - sbitmap_zero (g->nodes[i].successors); - g->nodes[i].predecessors = sbitmap_alloc (num_nodes); - sbitmap_zero (g->nodes[i].predecessors); - g->nodes[i].first_note = (first_note ? first_note : insn); - g->nodes[i++].insn = insn; - first_note = NULL_RTX; - } - - /* We must have found a branch in DDG. */ - gcc_assert (g->closing_branch); - - - /* Build the data dependency graph. */ - build_intra_loop_deps (g); - build_inter_loop_deps (g, df); - return g; -} - -/* Free all the memory allocated for the DDG. */ -void -free_ddg (ddg_ptr g) -{ - int i; - - if (!g) - return; - - for (i = 0; i < g->num_nodes; i++) - { - ddg_edge_ptr e = g->nodes[i].out; - - while (e) - { - ddg_edge_ptr next = e->next_out; - - free (e); - e = next; - } - sbitmap_free (g->nodes[i].successors); - sbitmap_free (g->nodes[i].predecessors); - } - if (g->num_backarcs > 0) - free (g->backarcs); - free (g->nodes); - free (g); -} - -void -print_ddg_edge (FILE *file, ddg_edge_ptr e) -{ - char dep_c; - - switch (e->type) { - case OUTPUT_DEP : - dep_c = 'O'; - break; - case ANTI_DEP : - dep_c = 'A'; - break; - default: - dep_c = 'T'; - } - - fprintf (file, " [%d -(%c,%d,%d)-> %d] ", INSN_UID (e->src->insn), - dep_c, e->latency, e->distance, INSN_UID (e->dest->insn)); -} - -/* Print the DDG nodes with there in/out edges to the dump file. */ -void -print_ddg (FILE *file, ddg_ptr g) -{ - int i; - - for (i = 0; i < g->num_nodes; i++) - { - ddg_edge_ptr e; - - print_rtl_single (file, g->nodes[i].insn); - fprintf (file, "OUT ARCS: "); - for (e = g->nodes[i].out; e; e = e->next_out) - print_ddg_edge (file, e); - - fprintf (file, "\nIN ARCS: "); - for (e = g->nodes[i].in; e; e = e->next_in) - print_ddg_edge (file, e); - - fprintf (file, "\n"); - } -} - -/* Print the given DDG in VCG format. */ -void -vcg_print_ddg (FILE *file, ddg_ptr g) -{ - int src_cuid; - - fprintf (file, "graph: {\n"); - for (src_cuid = 0; src_cuid < g->num_nodes; src_cuid++) - { - ddg_edge_ptr e; - int src_uid = INSN_UID (g->nodes[src_cuid].insn); - - fprintf (file, "node: {title: \"%d_%d\" info1: \"", src_cuid, src_uid); - print_rtl_single (file, g->nodes[src_cuid].insn); - fprintf (file, "\"}\n"); - for (e = g->nodes[src_cuid].out; e; e = e->next_out) - { - int dst_uid = INSN_UID (e->dest->insn); - int dst_cuid = e->dest->cuid; - - /* Give the backarcs a different color. */ - if (e->distance > 0) - fprintf (file, "backedge: {color: red "); - else - fprintf (file, "edge: { "); - - fprintf (file, "sourcename: \"%d_%d\" ", src_cuid, src_uid); - fprintf (file, "targetname: \"%d_%d\" ", dst_cuid, dst_uid); - fprintf (file, "label: \"%d_%d\"}\n", e->latency, e->distance); - } - } - fprintf (file, "}\n"); -} - -/* Create an edge and initialize it with given values. */ -static ddg_edge_ptr -create_ddg_edge (ddg_node_ptr src, ddg_node_ptr dest, - dep_type t, dep_data_type dt, int l, int d) -{ - ddg_edge_ptr e = (ddg_edge_ptr) xmalloc (sizeof (struct ddg_edge)); - - e->src = src; - e->dest = dest; - e->type = t; - e->data_type = dt; - e->latency = l; - e->distance = d; - e->next_in = e->next_out = NULL; - e->aux.info = 0; - return e; -} - -/* Add the given edge to the in/out linked lists of the DDG nodes. */ -static void -add_edge_to_ddg (ddg_ptr g ATTRIBUTE_UNUSED, ddg_edge_ptr e) -{ - ddg_node_ptr src = e->src; - ddg_node_ptr dest = e->dest; - - /* Should have allocated the sbitmaps. */ - gcc_assert (src->successors && dest->predecessors); - - SET_BIT (src->successors, dest->cuid); - SET_BIT (dest->predecessors, src->cuid); - e->next_in = dest->in; - dest->in = e; - e->next_out = src->out; - src->out = e; -} - - - -/* Algorithm for computing the recurrence_length of an scc. We assume at - for now that cycles in the data dependence graph contain a single backarc. - This simplifies the algorithm, and can be generalized later. */ -static void -set_recurrence_length (ddg_scc_ptr scc, ddg_ptr g) -{ - int j; - int result = -1; - - for (j = 0; j < scc->num_backarcs; j++) - { - ddg_edge_ptr backarc = scc->backarcs[j]; - int length; - int distance = backarc->distance; - ddg_node_ptr src = backarc->dest; - ddg_node_ptr dest = backarc->src; - - length = longest_simple_path (g, src->cuid, dest->cuid, scc->nodes); - if (length < 0 ) - { - /* fprintf (stderr, "Backarc not on simple cycle in SCC.\n"); */ - continue; - } - length += backarc->latency; - result = MAX (result, (length / distance)); - } - scc->recurrence_length = result; -} - -/* Create a new SCC given the set of its nodes. Compute its recurrence_length - and mark edges that belong to this scc as IN_SCC. */ -static ddg_scc_ptr -create_scc (ddg_ptr g, sbitmap nodes) -{ - ddg_scc_ptr scc; - unsigned int u = 0; - sbitmap_iterator sbi; - - scc = (ddg_scc_ptr) xmalloc (sizeof (struct ddg_scc)); - scc->backarcs = NULL; - scc->num_backarcs = 0; - scc->nodes = sbitmap_alloc (g->num_nodes); - sbitmap_copy (scc->nodes, nodes); - - /* Mark the backarcs that belong to this SCC. */ - EXECUTE_IF_SET_IN_SBITMAP (nodes, 0, u, sbi) - { - ddg_edge_ptr e; - ddg_node_ptr n = &g->nodes[u]; - - for (e = n->out; e; e = e->next_out) - if (TEST_BIT (nodes, e->dest->cuid)) - { - e->aux.count = IN_SCC; - if (e->distance > 0) - add_backarc_to_scc (scc, e); - } - } - - set_recurrence_length (scc, g); - return scc; -} - -/* Cleans the memory allocation of a given SCC. */ -static void -free_scc (ddg_scc_ptr scc) -{ - if (!scc) - return; - - sbitmap_free (scc->nodes); - if (scc->num_backarcs > 0) - free (scc->backarcs); - free (scc); -} - - -/* Add a given edge known to be a backarc to the given DDG. */ -static void -add_backarc_to_ddg (ddg_ptr g, ddg_edge_ptr e) -{ - int size = (g->num_backarcs + 1) * sizeof (ddg_edge_ptr); - - add_edge_to_ddg (g, e); - g->backarcs = (ddg_edge_ptr *) xrealloc (g->backarcs, size); - g->backarcs[g->num_backarcs++] = e; -} - -/* Add backarc to an SCC. */ -static void -add_backarc_to_scc (ddg_scc_ptr scc, ddg_edge_ptr e) -{ - int size = (scc->num_backarcs + 1) * sizeof (ddg_edge_ptr); - - scc->backarcs = (ddg_edge_ptr *) xrealloc (scc->backarcs, size); - scc->backarcs[scc->num_backarcs++] = e; -} - -/* Add the given SCC to the DDG. */ -static void -add_scc_to_ddg (ddg_all_sccs_ptr g, ddg_scc_ptr scc) -{ - int size = (g->num_sccs + 1) * sizeof (ddg_scc_ptr); - - g->sccs = (ddg_scc_ptr *) xrealloc (g->sccs, size); - g->sccs[g->num_sccs++] = scc; -} - -/* Given the instruction INSN return the node that represents it. */ -ddg_node_ptr -get_node_of_insn (ddg_ptr g, rtx insn) -{ - int i; - - for (i = 0; i < g->num_nodes; i++) - if (insn == g->nodes[i].insn) - return &g->nodes[i]; - return NULL; -} - -/* Given a set OPS of nodes in the DDG, find the set of their successors - which are not in OPS, and set their bits in SUCC. Bits corresponding to - OPS are cleared from SUCC. Leaves the other bits in SUCC unchanged. */ -void -find_successors (sbitmap succ, ddg_ptr g, sbitmap ops) -{ - unsigned int i = 0; - sbitmap_iterator sbi; - - EXECUTE_IF_SET_IN_SBITMAP (ops, 0, i, sbi) - { - const sbitmap node_succ = NODE_SUCCESSORS (&g->nodes[i]); - sbitmap_a_or_b (succ, succ, node_succ); - }; - - /* We want those that are not in ops. */ - sbitmap_difference (succ, succ, ops); -} - -/* Given a set OPS of nodes in the DDG, find the set of their predecessors - which are not in OPS, and set their bits in PREDS. Bits corresponding to - OPS are cleared from PREDS. Leaves the other bits in PREDS unchanged. */ -void -find_predecessors (sbitmap preds, ddg_ptr g, sbitmap ops) -{ - unsigned int i = 0; - sbitmap_iterator sbi; - - EXECUTE_IF_SET_IN_SBITMAP (ops, 0, i, sbi) - { - const sbitmap node_preds = NODE_PREDECESSORS (&g->nodes[i]); - sbitmap_a_or_b (preds, preds, node_preds); - }; - - /* We want those that are not in ops. */ - sbitmap_difference (preds, preds, ops); -} - - -/* Compare function to be passed to qsort to order the backarcs in descending - recMII order. */ -static int -compare_sccs (const void *s1, const void *s2) -{ - int rec_l1 = (*(ddg_scc_ptr *)s1)->recurrence_length; - int rec_l2 = (*(ddg_scc_ptr *)s2)->recurrence_length; - return ((rec_l2 > rec_l1) - (rec_l2 < rec_l1)); - -} - -/* Order the backarcs in descending recMII order using compare_sccs. */ -static void -order_sccs (ddg_all_sccs_ptr g) -{ - qsort (g->sccs, g->num_sccs, sizeof (ddg_scc_ptr), - (int (*) (const void *, const void *)) compare_sccs); -} - -/* Perform the Strongly Connected Components decomposing algorithm on the - DDG and return DDG_ALL_SCCS structure that contains them. */ -ddg_all_sccs_ptr -create_ddg_all_sccs (ddg_ptr g) -{ - int i; - int num_nodes = g->num_nodes; - sbitmap from = sbitmap_alloc (num_nodes); - sbitmap to = sbitmap_alloc (num_nodes); - sbitmap scc_nodes = sbitmap_alloc (num_nodes); - ddg_all_sccs_ptr sccs = (ddg_all_sccs_ptr) - xmalloc (sizeof (struct ddg_all_sccs)); - - sccs->ddg = g; - sccs->sccs = NULL; - sccs->num_sccs = 0; - - for (i = 0; i < g->num_backarcs; i++) - { - ddg_scc_ptr scc; - ddg_edge_ptr backarc = g->backarcs[i]; - ddg_node_ptr src = backarc->src; - ddg_node_ptr dest = backarc->dest; - - /* If the backarc already belongs to an SCC, continue. */ - if (backarc->aux.count == IN_SCC) - continue; - - sbitmap_zero (from); - sbitmap_zero (to); - SET_BIT (from, dest->cuid); - SET_BIT (to, src->cuid); - - if (find_nodes_on_paths (scc_nodes, g, from, to)) - { - scc = create_scc (g, scc_nodes); - add_scc_to_ddg (sccs, scc); - } - } - order_sccs (sccs); - sbitmap_free (from); - sbitmap_free (to); - sbitmap_free (scc_nodes); - return sccs; -} - -/* Frees the memory allocated for all SCCs of the DDG, but keeps the DDG. */ -void -free_ddg_all_sccs (ddg_all_sccs_ptr all_sccs) -{ - int i; - - if (!all_sccs) - return; - - for (i = 0; i < all_sccs->num_sccs; i++) - free_scc (all_sccs->sccs[i]); - - free (all_sccs); -} - - -/* Given FROM - a bitmap of source nodes - and TO - a bitmap of destination - nodes - find all nodes that lie on paths from FROM to TO (not excluding - nodes from FROM and TO). Return nonzero if nodes exist. */ -int -find_nodes_on_paths (sbitmap result, ddg_ptr g, sbitmap from, sbitmap to) -{ - int answer; - int change; - unsigned int u = 0; - int num_nodes = g->num_nodes; - sbitmap_iterator sbi; - - sbitmap workset = sbitmap_alloc (num_nodes); - sbitmap reachable_from = sbitmap_alloc (num_nodes); - sbitmap reach_to = sbitmap_alloc (num_nodes); - sbitmap tmp = sbitmap_alloc (num_nodes); - - sbitmap_copy (reachable_from, from); - sbitmap_copy (tmp, from); - - change = 1; - while (change) - { - change = 0; - sbitmap_copy (workset, tmp); - sbitmap_zero (tmp); - EXECUTE_IF_SET_IN_SBITMAP (workset, 0, u, sbi) - { - ddg_edge_ptr e; - ddg_node_ptr u_node = &g->nodes[u]; - - for (e = u_node->out; e != (ddg_edge_ptr) 0; e = e->next_out) - { - ddg_node_ptr v_node = e->dest; - int v = v_node->cuid; - - if (!TEST_BIT (reachable_from, v)) - { - SET_BIT (reachable_from, v); - SET_BIT (tmp, v); - change = 1; - } - } - } - } - - sbitmap_copy (reach_to, to); - sbitmap_copy (tmp, to); - - change = 1; - while (change) - { - change = 0; - sbitmap_copy (workset, tmp); - sbitmap_zero (tmp); - EXECUTE_IF_SET_IN_SBITMAP (workset, 0, u, sbi) - { - ddg_edge_ptr e; - ddg_node_ptr u_node = &g->nodes[u]; - - for (e = u_node->in; e != (ddg_edge_ptr) 0; e = e->next_in) - { - ddg_node_ptr v_node = e->src; - int v = v_node->cuid; - - if (!TEST_BIT (reach_to, v)) - { - SET_BIT (reach_to, v); - SET_BIT (tmp, v); - change = 1; - } - } - } - } - - answer = sbitmap_a_and_b_cg (result, reachable_from, reach_to); - sbitmap_free (workset); - sbitmap_free (reachable_from); - sbitmap_free (reach_to); - sbitmap_free (tmp); - return answer; -} - - -/* Updates the counts of U_NODE's successors (that belong to NODES) to be - at-least as large as the count of U_NODE plus the latency between them. - Sets a bit in TMP for each successor whose count was changed (increased). - Returns nonzero if any count was changed. */ -static int -update_dist_to_successors (ddg_node_ptr u_node, sbitmap nodes, sbitmap tmp) -{ - ddg_edge_ptr e; - int result = 0; - - for (e = u_node->out; e; e = e->next_out) - { - ddg_node_ptr v_node = e->dest; - int v = v_node->cuid; - - if (TEST_BIT (nodes, v) - && (e->distance == 0) - && (v_node->aux.count < u_node->aux.count + e->latency)) - { - v_node->aux.count = u_node->aux.count + e->latency; - SET_BIT (tmp, v); - result = 1; - } - } - return result; -} - - -/* Find the length of a longest path from SRC to DEST in G, - going only through NODES, and disregarding backarcs. */ -int -longest_simple_path (struct ddg * g, int src, int dest, sbitmap nodes) -{ - int i; - unsigned int u = 0; - int change = 1; - int result; - int num_nodes = g->num_nodes; - sbitmap workset = sbitmap_alloc (num_nodes); - sbitmap tmp = sbitmap_alloc (num_nodes); - - - /* Data will hold the distance of the longest path found so far from - src to each node. Initialize to -1 = less than minimum. */ - for (i = 0; i < g->num_nodes; i++) - g->nodes[i].aux.count = -1; - g->nodes[src].aux.count = 0; - - sbitmap_zero (tmp); - SET_BIT (tmp, src); - - while (change) - { - sbitmap_iterator sbi; - - change = 0; - sbitmap_copy (workset, tmp); - sbitmap_zero (tmp); - EXECUTE_IF_SET_IN_SBITMAP (workset, 0, u, sbi) - { - ddg_node_ptr u_node = &g->nodes[u]; - - change |= update_dist_to_successors (u_node, nodes, tmp); - } - } - result = g->nodes[dest].aux.count; - sbitmap_free (workset); - sbitmap_free (tmp); - return result; -} |