From 50e9ff8378be0c7353d3f3fb6fa4e4dc3c3367e6 Mon Sep 17 00:00:00 2001 From: James Greenhalgh Date: Sat, 6 Dec 2014 19:19:37 +0000 Subject: [PATCH] extend jump thread for finite state automata PR tree-optimization/54742 * params.def (max-fsm-thread-path-insns, max-fsm-thread-length, max-fsm-thread-paths): New. * doc/invoke.texi (max-fsm-thread-path-insns, max-fsm-thread-length, max-fsm-thread-paths): Documented. * tree-cfg.c (split_edge_bb_loc): Export. * tree-cfg.h (split_edge_bb_loc): Declared extern. * tree-ssa-threadedge.c (simplify_control_stmt_condition): Restore the original value of cond when simplification fails. (fsm_find_thread_path): New. (fsm_find_control_statement_thread_paths): New. (thread_through_normal_block): Call find_control_statement_thread_paths. * tree-ssa-threadupdate.c (dump_jump_thread_path): Pretty print EDGE_FSM_THREAD. (verify_seme): New. (duplicate_seme_region): New. (thread_through_all_blocks): Generate code for EDGE_FSM_THREAD edges calling duplicate_seme_region. * tree-ssa-threadupdate.h (jump_thread_edge_type): Add EDGE_FSM_THREAD. * testsuite/gcc.dg/tree-ssa/ssa-dom-thread-6.c: New test. * testsuite/gcc.dg/tree-ssa/ssa-dom-thread-7.c: New test. Co-Authored-By: Brian Rzycki Co-Authored-By: Sebastian Pop From-SVN: r218451 --- gcc/ChangeLog | 29 ++ gcc/doc/invoke.texi | 12 + gcc/params.def | 15 + gcc/testsuite/ChangeLog | 8 + .../gcc.dg/tree-ssa/ssa-dom-thread-6.c | 43 +++ .../gcc.dg/tree-ssa/ssa-dom-thread-7.c | 127 ++++++++ gcc/tree-cfg.c | 2 +- gcc/tree-cfg.h | 1 + gcc/tree-ssa-threadedge.c | 278 +++++++++++++++++- gcc/tree-ssa-threadupdate.c | 203 ++++++++++++- gcc/tree-ssa-threadupdate.h | 1 + 11 files changed, 716 insertions(+), 3 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-thread-6.c create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-thread-7.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index b340b51fe48..6cfd339db89 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,32 @@ +2014-12-06 James Greenhalgh + Sebastian Pop + Brian Rzycki + + PR tree-optimization/54742 + * params.def (max-fsm-thread-path-insns, max-fsm-thread-length, + max-fsm-thread-paths): New. + + * doc/invoke.texi (max-fsm-thread-path-insns, max-fsm-thread-length, + max-fsm-thread-paths): Documented. + + * tree-cfg.c (split_edge_bb_loc): Export. + * tree-cfg.h (split_edge_bb_loc): Declared extern. + + * tree-ssa-threadedge.c (simplify_control_stmt_condition): Restore the + original value of cond when simplification fails. + (fsm_find_thread_path): New. + (fsm_find_control_statement_thread_paths): New. + (thread_through_normal_block): Call find_control_statement_thread_paths. + + * tree-ssa-threadupdate.c (dump_jump_thread_path): Pretty print + EDGE_FSM_THREAD. + (verify_seme): New. + (duplicate_seme_region): New. + (thread_through_all_blocks): Generate code for EDGE_FSM_THREAD edges + calling duplicate_seme_region. + + * tree-ssa-threadupdate.h (jump_thread_edge_type): Add EDGE_FSM_THREAD. + 2014-12-06 H.J. Lu PR target/64200 diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 82f079420fc..70d1336b6ac 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -10623,6 +10623,18 @@ large and significantly increase compile time at optimization level @option{-O1} and higher. This parameter is a maximum nubmer of statements in a single generated constructor. Default value is 5000. +@item max-fsm-thread-path-insns +Maximum number of instructions to copy when duplicating blocks on a +finite state automaton jump thread path. The default is 100. + +@item max-fsm-thread-length +Maximum number of basic blocks on a finite state automaton jump thread +path. The default is 10. + +@item max-fsm-thread-paths +Maximum number of new jump thread paths to create for a finite state +automaton. The default is 50. + @end table @end table diff --git a/gcc/params.def b/gcc/params.def index 9b21c07bf4e..edf3f53e605 100644 --- a/gcc/params.def +++ b/gcc/params.def @@ -1140,6 +1140,21 @@ DEFPARAM (PARAM_CHKP_MAX_CTOR_SIZE, "Maximum number of statements to be included into a single static " "constructor generated by Pointer Bounds Checker", 5000, 100, 0) + +DEFPARAM (PARAM_MAX_FSM_THREAD_PATH_INSNS, + "max-fsm-thread-path-insns", + "Maximum number of instructions to copy when duplicating blocks on a finite state automaton jump thread path", + 100, 1, 999999) + +DEFPARAM (PARAM_MAX_FSM_THREAD_LENGTH, + "max-fsm-thread-length", + "Maximum number of basic blocks on a finite state automaton jump thread path", + 10, 1, 999999) + +DEFPARAM (PARAM_MAX_FSM_THREAD_PATHS, + "max-fsm-thread-paths", + "Maximum number of new jump thread paths to create for a finite state automaton", + 50, 1, 999999) /* Local variables: diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index abeacd0a55d..4c8939757be 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,11 @@ +2014-12-06 James Greenhalgh + Sebastian Pop + Brian Rzycki + + PR tree-optimization/54742 + * gcc.dg/tree-ssa/ssa-dom-thread-6.c: New test. + * gcc.dg/tree-ssa/ssa-dom-thread-7.c: New test. + 2014-12-06 Marek Polacek PR tree-optimization/64183 diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-thread-6.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-thread-6.c new file mode 100644 index 00000000000..bb34a7432e1 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-thread-6.c @@ -0,0 +1,43 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-dom1-details" } */ +/* { dg-final { scan-tree-dump-times "FSM" 6 "dom1" } } */ +/* { dg-final { cleanup-tree-dump "dom1" } } */ + +int sum0, sum1, sum2, sum3; +int foo (char *s, char **ret) +{ + int state=0; + char c; + + for (; *s && state != 4; s++) + { + c = *s; + if (c == '*') + { + s++; + break; + } + switch (state) + { + case 0: + if (c == '+') + state = 1; + else if (c != '-') + sum0+=c; + break; + case 1: + if (c == '+') + state = 2; + else if (c == '-') + state = 0; + else + sum1+=c; + break; + default: + break; + } + + } + *ret = s; + return state; +} diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-thread-7.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-thread-7.c new file mode 100644 index 00000000000..21474f0b496 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-thread-7.c @@ -0,0 +1,127 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-dom1-details" } */ +/* { dg-final { scan-tree-dump-times "FSM" 19 "dom1" } } */ +/* { dg-final { cleanup-tree-dump "dom1" } } */ + +enum STATE { + S0=0, + SI, + S1, + S2, + S3, + S4, + S5, + S6 +}; + +int bar (enum STATE s); + +enum STATE foo (unsigned char **y, unsigned *c) +{ + unsigned char *x = *y; + unsigned char n; + enum STATE s = S0; + + for( ; *x && s != SI; x++ ) + { + n = *x; + if (n == 'x') + { + x++; + break; + } + switch(s) + { + case S0: + if(bar(n)) + s = S3; + else if( n == 'a' || n == 'b' ) + s = S1; + else if( n == 'c' ) + s = S4; + else + { + s = SI; + c[SI]++; + } + c[S0]++; + break; + case S1: + if(bar(n)) + { + s = S3; + c[S1]++; + } + else if( n == 'c' ) + { + s = S4; + c[S1]++; + } + else + { + s = SI; + c[S1]++; + } + break; + case S3: + if( n == 'c' ) + { + s = S4; + c[S3]++; + } + else if(!bar(n)) + { + s = SI; + c[S3]++; + } + break; + case S4: + if( n == 'E' || n == 'e' ) + { + s = S2; + c[S4]++; + } + else if(!bar(n)) + { + s = SI; + c[S4]++; + } + break; + case S2: + if( n == 'a' || n == 'b' ) + { + s = S5; + c[S2]++; + } + else + { + s = SI; + c[S2]++; + } + break; + case S5: + if(bar(n)) + { + s = S6; + c[S5]++; + } + else + { + s = SI; + c[S5]++; + } + break; + case S6: + if(!bar(n)) + { + s = SI; + c[SI]++; + } + break; + default: + break; + } + } + *y=x; + return s; +} diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c index fbbe9c8a9a5..6aca58d27d6 100644 --- a/gcc/tree-cfg.c +++ b/gcc/tree-cfg.c @@ -2666,7 +2666,7 @@ reinstall_phi_args (edge new_edge, edge old_edge) near its "logical" location. This is of most help to humans looking at debugging dumps. */ -static basic_block +basic_block split_edge_bb_loc (edge edge_in) { basic_block dest = edge_in->dest; diff --git a/gcc/tree-cfg.h b/gcc/tree-cfg.h index d35e5ba41a6..834fa719250 100644 --- a/gcc/tree-cfg.h +++ b/gcc/tree-cfg.h @@ -67,6 +67,7 @@ extern void verify_gimple_in_cfg (struct function *, bool); extern tree gimple_block_label (basic_block); extern void add_phi_args_after_copy_bb (basic_block); extern void add_phi_args_after_copy (basic_block *, unsigned, edge); +extern basic_block split_edge_bb_loc (edge); extern bool gimple_duplicate_sese_region (edge, edge, basic_block *, unsigned, basic_block *, bool); extern bool gimple_duplicate_sese_tail (edge, edge, basic_block *, unsigned, diff --git a/gcc/tree-ssa-threadedge.c b/gcc/tree-ssa-threadedge.c index 8b0b7b801a1..ce7031112a4 100644 --- a/gcc/tree-ssa-threadedge.c +++ b/gcc/tree-ssa-threadedge.c @@ -56,6 +56,8 @@ along with GCC; see the file COPYING3. If not see #include "params.h" #include "tree-ssa-threadedge.h" #include "builtins.h" +#include "cfg.h" +#include "cfganal.h" /* To avoid code explosion due to jump threading, we limit the number of statements we are going to copy. This variable @@ -661,6 +663,7 @@ simplify_control_stmt_condition (edge e, rather than use a relational operator. These are simpler to handle. */ if (TREE_CODE (cond) == SSA_NAME) { + tree original_lhs = cond; cached_lhs = cond; /* Get the variable's current value from the equivalence chains. @@ -689,6 +692,12 @@ simplify_control_stmt_condition (edge e, pass specific callback to try and simplify it further. */ if (cached_lhs && ! is_gimple_min_invariant (cached_lhs)) cached_lhs = (*simplify) (stmt, stmt); + + /* We couldn't find an invariant. But, callers of this + function may be able to do something useful with the + unmodified destination. */ + if (!cached_lhs) + cached_lhs = original_lhs; } else cached_lhs = NULL; @@ -948,6 +957,249 @@ thread_around_empty_blocks (edge taken_edge, return false; } +/* Return true if the CFG contains at least one path from START_BB to END_BB. + When a path is found, record in PATH the blocks from END_BB to START_BB. + VISITED_BBS is used to make sure we don't fall into an infinite loop. Bound + the recursion to basic blocks belonging to LOOP. */ + +static bool +fsm_find_thread_path (basic_block start_bb, basic_block end_bb, + vec *&path, + hash_set *visited_bbs, loop_p loop) +{ + if (loop != start_bb->loop_father) + return false; + + if (start_bb == end_bb) + { + vec_safe_push (path, start_bb); + return true; + } + + if (!visited_bbs->add (start_bb)) + { + edge e; + edge_iterator ei; + FOR_EACH_EDGE (e, ei, start_bb->succs) + if (fsm_find_thread_path (e->dest, end_bb, path, visited_bbs, loop)) + { + vec_safe_push (path, start_bb); + return true; + } + } + + return false; +} + +static int max_threaded_paths; + +/* We trace the value of the variable EXPR back through any phi nodes looking + for places where it gets a constant value and save the path. Stop after + having recorded MAX_PATHS jump threading paths. */ + +static void +fsm_find_control_statement_thread_paths (tree expr, + hash_set *visited_phis, + vec *&path) +{ + tree var = SSA_NAME_VAR (expr); + gimple def_stmt = SSA_NAME_DEF_STMT (expr); + basic_block var_bb = gimple_bb (def_stmt); + + if (var == NULL || var_bb == NULL) + return; + + /* For the moment we assume that an SSA chain only contains phi nodes, and + eventually one of the phi arguments will be an integer constant. In the + future, this could be extended to also handle simple assignments of + arithmetic operations. */ + if (gimple_code (def_stmt) != GIMPLE_PHI) + return; + + /* Avoid infinite recursion. */ + if (visited_phis->add (def_stmt)) + return; + + gphi *phi = as_a (def_stmt); + int next_path_length = 0; + basic_block last_bb_in_path = path->last (); + + /* Following the chain of SSA_NAME definitions, we jumped from a definition in + LAST_BB_IN_PATH to a definition in VAR_BB. When these basic blocks are + different, append to PATH the blocks from LAST_BB_IN_PATH to VAR_BB. */ + if (var_bb != last_bb_in_path) + { + edge e; + int e_count = 0; + edge_iterator ei; + vec *next_path; + vec_alloc (next_path, n_basic_blocks_for_fn (cfun)); + + FOR_EACH_EDGE (e, ei, last_bb_in_path->preds) + { + hash_set *visited_bbs = new hash_set; + + if (fsm_find_thread_path (var_bb, e->src, next_path, visited_bbs, + e->src->loop_father)) + ++e_count; + + delete visited_bbs; + + /* If there is more than one path, stop. */ + if (e_count > 1) + { + vec_free (next_path); + return; + } + } + + /* Stop if we have not found a path: this could occur when the recursion + is stopped by one of the bounds. */ + if (e_count == 0) + { + vec_free (next_path); + return; + } + + /* Append all the nodes from NEXT_PATH to PATH. */ + vec_safe_splice (path, next_path); + next_path_length = next_path->length (); + vec_free (next_path); + } + + gcc_assert (path->last () == var_bb); + + /* Iterate over the arguments of PHI. */ + unsigned int i; + for (i = 0; i < gimple_phi_num_args (phi); i++) + { + tree arg = gimple_phi_arg_def (phi, i); + basic_block bbi = gimple_phi_arg_edge (phi, i)->src; + + /* Skip edges pointing outside the current loop. */ + if (!arg || var_bb->loop_father != bbi->loop_father) + continue; + + if (TREE_CODE (arg) == SSA_NAME) + { + vec_safe_push (path, bbi); + /* Recursively follow SSA_NAMEs looking for a constant definition. */ + fsm_find_control_statement_thread_paths (arg, visited_phis, path); + path->pop (); + continue; + } + + if (TREE_CODE (arg) != INTEGER_CST) + continue; + + int path_length = path->length (); + /* A path with less than 2 basic blocks should not be jump-threaded. */ + if (path_length < 2) + continue; + + if (path_length > PARAM_VALUE (PARAM_MAX_FSM_THREAD_LENGTH)) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, "FSM jump-thread path not considered: " + "the number of basic blocks on the path " + "exceeds PARAM_MAX_FSM_THREAD_LENGTH.\n"); + continue; + } + + if (max_threaded_paths <= 0) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, "FSM jump-thread path not considered: " + "the number of previously recorded FSM paths to thread " + "exceeds PARAM_MAX_FSM_THREAD_PATHS.\n"); + continue; + } + + /* Add BBI to the path. */ + vec_safe_push (path, bbi); + ++path_length; + + int n_insns = 0; + gimple_stmt_iterator gsi; + int j; + loop_p loop = (*path)[0]->loop_father; + bool path_crosses_loops = false; + + /* Count the number of instructions on the path: as these instructions + will have to be duplicated, we will not record the path if there are + too many instructions on the path. Also check that all the blocks in + the path belong to a single loop. */ + for (j = 1; j < path_length - 1; j++) + { + basic_block bb = (*path)[j]; + + if (bb->loop_father != loop) + { + path_crosses_loops = true; + break; + } + + for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) + { + gimple stmt = gsi_stmt (gsi); + /* Do not count empty statements and labels. */ + if (gimple_code (stmt) != GIMPLE_NOP + && gimple_code (stmt) != GIMPLE_LABEL + && !is_gimple_debug (stmt)) + ++n_insns; + } + } + + if (path_crosses_loops) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, "FSM jump-thread path not considered: " + "the path crosses loops.\n"); + path->pop (); + continue; + } + + if (n_insns >= PARAM_VALUE (PARAM_MAX_FSM_THREAD_PATH_INSNS)) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, "FSM jump-thread path not considered: " + "the number of instructions on the path " + "exceeds PARAM_MAX_FSM_THREAD_PATH_INSNS.\n"); + path->pop (); + continue; + } + + vec *jump_thread_path + = new vec (); + + /* Record the edges between the blocks in PATH. */ + for (j = 0; j < path_length - 1; j++) + { + edge e = find_edge ((*path)[path_length - j - 1], + (*path)[path_length - j - 2]); + gcc_assert (e); + jump_thread_edge *x = new jump_thread_edge (e, EDGE_FSM_THREAD); + jump_thread_path->safe_push (x); + } + + /* Add the edge taken when the control variable has value ARG. */ + edge taken_edge = find_taken_edge ((*path)[0], arg); + jump_thread_edge *x + = new jump_thread_edge (taken_edge, EDGE_NO_COPY_SRC_BLOCK); + jump_thread_path->safe_push (x); + + register_jump_thread (jump_thread_path); + --max_threaded_paths; + + /* Remove BBI from the path. */ + path->pop (); + } + + /* Remove all the nodes that we added from NEXT_PATH. */ + if (next_path_length) + vec_safe_truncate (path, (path->length () - next_path_length)); +} + /* We are exiting E->src, see if E->dest ends with a conditional jump which has a known value when reached via E. @@ -1033,7 +1285,10 @@ thread_through_normal_block (edge e, cond = simplify_control_stmt_condition (e, stmt, dummy_cond, simplify, handle_dominating_asserts); - if (cond && is_gimple_min_invariant (cond)) + if (!cond) + return 0; + + if (is_gimple_min_invariant (cond)) { edge taken_edge = find_taken_edge (e->dest, cond); basic_block dest = (taken_edge ? taken_edge->dest : NULL); @@ -1079,6 +1334,27 @@ thread_through_normal_block (edge e, backedge_seen_p); return 1; } + + if (!flag_expensive_optimizations + || optimize_function_for_size_p (cfun) + || TREE_CODE (cond) != SSA_NAME + || e->dest->loop_father != e->src->loop_father + || loop_depth (e->dest->loop_father) == 0) + return 0; + + /* When COND cannot be simplified, try to find paths from a control + statement back through the PHI nodes which would affect that control + statement. */ + vec *bb_path; + vec_alloc (bb_path, n_basic_blocks_for_fn (cfun)); + vec_safe_push (bb_path, e->dest); + hash_set *visited_phis = new hash_set; + + max_threaded_paths = PARAM_VALUE (PARAM_MAX_FSM_THREAD_PATHS); + fsm_find_control_statement_thread_paths (cond, visited_phis, bb_path); + + delete visited_phis; + vec_free (bb_path); } return 0; } diff --git a/gcc/tree-ssa-threadupdate.c b/gcc/tree-ssa-threadupdate.c index a8243aea68a..12f83ba64af 100644 --- a/gcc/tree-ssa-threadupdate.c +++ b/gcc/tree-ssa-threadupdate.c @@ -167,8 +167,9 @@ dump_jump_thread_path (FILE *dump_file, vec path, bool registering) { fprintf (dump_file, - " %s jump thread: (%d, %d) incoming edge; ", + " %s%s jump thread: (%d, %d) incoming edge; ", (registering ? "Registering" : "Cancelling"), + (path[0]->type == EDGE_FSM_THREAD ? " FSM": ""), path[0]->e->src->index, path[0]->e->dest->index); for (unsigned int i = 1; i < path.length (); i++) @@ -2317,6 +2318,155 @@ bb_ends_with_multiway_branch (basic_block bb ATTRIBUTE_UNUSED) return false; } +/* Verify that the REGION is a Single Entry Multiple Exits region: make sure no + edge other than ENTRY is entering the REGION. */ + +DEBUG_FUNCTION void +verify_seme (edge entry, basic_block *region, unsigned n_region) +{ + bitmap bbs = BITMAP_ALLOC (NULL); + + for (unsigned i = 0; i < n_region; i++) + bitmap_set_bit (bbs, region[i]->index); + + for (unsigned i = 0; i < n_region; i++) + { + edge e; + edge_iterator ei; + basic_block bb = region[i]; + + /* All predecessors other than ENTRY->src should be in the region. */ + for (ei = ei_start (bb->preds); (e = ei_safe_edge (ei)); ei_next (&ei)) + if (e != entry) + gcc_assert (bitmap_bit_p (bbs, e->src->index)); + } + + BITMAP_FREE (bbs); +} + +/* Duplicates a Single Entry Multiple Exit REGION (set of N_REGION basic + blocks). The ENTRY edge is redirected to the duplicate of the region. If + REGION is not a Single Entry region, ignore any incoming edges other than + ENTRY: this makes the copied region a Single Entry region. + + Remove the last conditional statement in the last basic block in the REGION, + and create a single fallthru edge pointing to the same destination as the + EXIT edge. + + The new basic blocks are stored to REGION_COPY in the same order as they had + in REGION, provided that REGION_COPY is not NULL. + + Returns false if it is unable to copy the region, true otherwise. */ + +static bool +duplicate_seme_region (edge entry, edge exit, + basic_block *region, unsigned n_region, + basic_block *region_copy) +{ + unsigned i; + bool free_region_copy = false, copying_header = false; + struct loop *loop = entry->dest->loop_father; + edge exit_copy; + edge redirected; + int total_freq = 0, entry_freq = 0; + gcov_type total_count = 0, entry_count = 0; + + if (!can_copy_bbs_p (region, n_region)) + return false; + + /* Some sanity checking. Note that we do not check for all possible + missuses of the functions. I.e. if you ask to copy something weird, + it will work, but the state of structures probably will not be + correct. */ + for (i = 0; i < n_region; i++) + { + /* We do not handle subloops, i.e. all the blocks must belong to the + same loop. */ + if (region[i]->loop_father != loop) + return false; + } + + initialize_original_copy_tables (); + + if (copying_header) + set_loop_copy (loop, loop_outer (loop)); + else + set_loop_copy (loop, loop); + + if (!region_copy) + { + region_copy = XNEWVEC (basic_block, n_region); + free_region_copy = true; + } + + if (entry->dest->count) + { + total_count = entry->dest->count; + entry_count = entry->count; + /* Fix up corner cases, to avoid division by zero or creation of negative + frequencies. */ + if (entry_count > total_count) + entry_count = total_count; + } + else + { + total_freq = entry->dest->frequency; + entry_freq = EDGE_FREQUENCY (entry); + /* Fix up corner cases, to avoid division by zero or creation of negative + frequencies. */ + if (total_freq == 0) + total_freq = 1; + else if (entry_freq > total_freq) + entry_freq = total_freq; + } + + copy_bbs (region, n_region, region_copy, &exit, 1, &exit_copy, loop, + split_edge_bb_loc (entry), 0); + if (total_count) + { + scale_bbs_frequencies_gcov_type (region, n_region, + total_count - entry_count, + total_count); + scale_bbs_frequencies_gcov_type (region_copy, n_region, entry_count, + total_count); + } + else + { + scale_bbs_frequencies_int (region, n_region, total_freq - entry_freq, + total_freq); + scale_bbs_frequencies_int (region_copy, n_region, entry_freq, total_freq); + } + +#ifdef ENABLE_CHECKING + /* Make sure no edge other than ENTRY is entering the copied region. */ + verify_seme (entry, region_copy, n_region); +#endif + + /* Remove the last branch in the jump thread path. */ + remove_ctrl_stmt_and_useless_edges (region_copy[n_region - 1], exit->dest); + edge e = make_edge (region_copy[n_region - 1], exit->dest, EDGE_FALLTHRU); + + if (e) { + rescan_loop_exit (e, true, false); + e->probability = REG_BR_PROB_BASE; + e->count = region_copy[n_region - 1]->count; + } + + /* Redirect the entry and add the phi node arguments. */ + redirected = redirect_edge_and_branch (entry, get_bb_copy (entry->dest)); + gcc_assert (redirected != NULL); + flush_pending_stmts (entry); + + /* Add the other PHI node arguments. */ + add_phi_args_after_copy (region_copy, n_region, NULL); + + if (free_region_copy) + free (region_copy); + + free_original_copy_tables (); + return true; +} + /* Walk through all blocks and thread incoming edges to the appropriate outgoing edge for each edge pair recorded in THREADED_EDGES. @@ -2343,6 +2493,57 @@ thread_through_all_blocks (bool may_peel_loop_headers) threaded_blocks = BITMAP_ALLOC (NULL); memset (&thread_stats, 0, sizeof (thread_stats)); + /* Jump-thread all FSM threads before other jump-threads. */ + for (i = 0; i < paths.length ();) + { + vec *path = paths[i]; + edge entry = (*path)[0]->e; + + if ((*path)[0]->type != EDGE_FSM_THREAD + /* Do not jump-thread twice from the same block. */ + || bitmap_bit_p (threaded_blocks, entry->src->index)) { + i++; + continue; + } + + unsigned len = path->length (); + edge exit = (*path)[len - 1]->e; + basic_block *region = XNEWVEC (basic_block, len - 1); + + for (unsigned int j = 0; j < len - 1; j++) + region[j] = (*path)[j]->e->dest; + + if (duplicate_seme_region (entry, exit, region, len - 1, NULL)) + { + /* We do not update dominance info. */ + free_dominance_info (CDI_DOMINATORS); + bitmap_set_bit (threaded_blocks, entry->src->index); + retval = true; + } + + delete_jump_thread_path (path); + paths.unordered_remove (i); + } + + /* Remove from PATHS all the jump-threads starting with an edge already + jump-threaded. */ + for (i = 0; i < paths.length ();) + { + vec *path = paths[i]; + edge entry = (*path)[0]->e; + + /* Do not jump-thread twice from the same block. */ + if (bitmap_bit_p (threaded_blocks, entry->src->index)) + { + delete_jump_thread_path (path); + paths.unordered_remove (i); + } + else + i++; + } + + bitmap_clear (threaded_blocks); + mark_threaded_blocks (threaded_blocks); initialize_original_copy_tables (); diff --git a/gcc/tree-ssa-threadupdate.h b/gcc/tree-ssa-threadupdate.h index 426aca5e688..22c5bceb90f 100644 --- a/gcc/tree-ssa-threadupdate.h +++ b/gcc/tree-ssa-threadupdate.h @@ -26,6 +26,7 @@ extern bool thread_through_all_blocks (bool); enum jump_thread_edge_type { EDGE_START_JUMP_THREAD, + EDGE_FSM_THREAD, EDGE_COPY_SRC_BLOCK, EDGE_COPY_SRC_JOINER_BLOCK, EDGE_NO_COPY_SRC_BLOCK -- 2.30.2