diff options
| -rw-r--r-- | gcc/ChangeLog | 17 | ||||
| -rw-r--r-- | gcc/ipa-pure-const.c | 6 | ||||
| -rw-r--r-- | gcc/passes.c | 1 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 10 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/loop-10.c | 2 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/loop-24.c | 6 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/loop-25.c | 2 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/loop-26.c | 6 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/loop-29.c | 6 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/pr32044.c | 7 | ||||
| -rw-r--r-- | gcc/testsuite/gnat.dg/loop_optimization6.adb | 2 | ||||
| -rw-r--r-- | gcc/tree-flow.h | 1 | ||||
| -rw-r--r-- | gcc/tree-ssa-dce.c | 132 | ||||
| -rw-r--r-- | gcc/tree-ssa-loop-ivcanon.c | 184 | ||||
| -rw-r--r-- | gcc/tree-ssa-loop.c | 31 |
15 files changed, 152 insertions, 261 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 552fd4481ef..c2655c81146 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,20 @@ +2009-07-03 Jan Hubicka <jh@suse.cz> + + * ipa-pure-const.c (analyze): Update loop optimizer init. + * tree-ssa-loop-iv-canon.c (empty_loop_p, remove_empty_loop, + try_remove_empty_loop, remove_empty_loops): Remove. + * tree-ssa-loop.c (tree_ssa_empty_loop, pass_empty_loop): Remove. + * tree-ssa-dce.c (find_obviously_necessary_stmts): Use finiteness info + to mark regular loops as neccesary. + (degenerate_phi_p): New function. + (propagate_necessity, remove_dead_phis): Use it. + (forward_edge_to_pdom): Likewise. + (eliminate_unnecessary_stmts): Take care to remove uses of results of + virtual PHI nodes that became unreachable. + (perform_tree_ssa_dce): Initialize/deinitialize loop optimizer. + * tree-flow.h (remove_empty_loops): Remove. + * passes.c (init_optimization_passes): Remove. + 2009-07-03 Uros Bizjak <ubizjak@gmail.com> * config/i386/i386.md (fix_trunc<mode>_fisttp_i387_1): Use diff --git a/gcc/ipa-pure-const.c b/gcc/ipa-pure-const.c index ba4782bc5f3..4e62eb187a4 100644 --- a/gcc/ipa-pure-const.c +++ b/gcc/ipa-pure-const.c @@ -535,7 +535,11 @@ end: effect. */ if (mark_dfs_back_edges ()) { - loop_optimizer_init (LOOPS_HAVE_PREHEADERS); + /* Preheaders are needed for SCEV to work. + Simple lateches and recorded exits improve chances that loop will + proved to be finite in testcases such as in loop-15.c and loop-24.c */ + loop_optimizer_init (LOOPS_NORMAL + | LOOPS_HAVE_RECORDED_EXITS); if (dump_file && (dump_flags & TDF_DETAILS)) flow_loops_dump (dump_file, NULL, 0); if (mark_irreducible_loops ()) diff --git a/gcc/passes.c b/gcc/passes.c index 36ffd222135..ca69beefd32 100644 --- a/gcc/passes.c +++ b/gcc/passes.c @@ -651,7 +651,6 @@ init_optimization_passes (void) NEXT_PASS (pass_lim); NEXT_PASS (pass_tree_unswitch); NEXT_PASS (pass_scev_cprop); - NEXT_PASS (pass_empty_loop); NEXT_PASS (pass_record_bounds); NEXT_PASS (pass_check_data_deps); NEXT_PASS (pass_loop_distribution); diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 51536203bb5..42a5374dd48 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,13 @@ +2009-07-03 Jan Hubicka <jh@suse.cz> + + * gcc.dg/tree-ssa/loop-24.c: Update dump file matching; enable -O2. + * gcc.dg/tree-ssa/loop-25.c: Likewise. + * gcc.dg/tree-ssa/loop-26.c: Likewise. + * gcc.dg/tree-ssa/pr32044.c: Likewise. + * gcc.dg/tree-ssa/loop-29.c: Likewise. + * gcc.dg/tree-ssa/loop-10.c: Likewise. + * gnat.dg/loop_optimization6.adb: Enable -O2. + 2009-07-02 Mark Mitchell <mark@codesourcery.com> * g++.dg/warn/null4.C: Extend. diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loop-10.c b/gcc/testsuite/gcc.dg/tree-ssa/loop-10.c index 03c2ddd515d..c8d118e3771 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/loop-10.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/loop-10.c @@ -1,5 +1,5 @@ /* { dg-do compile } */ -/* { dg-options "-O1 -fdump-tree-optimized" } */ +/* { dg-options "-O2 -fdump-tree-optimized" } */ /* { dg-require-effective-target int32plus } */ int bar (void); diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loop-24.c b/gcc/testsuite/gcc.dg/tree-ssa/loop-24.c index dfad30dcd3d..5632b067990 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/loop-24.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/loop-24.c @@ -1,5 +1,5 @@ /* { dg-do compile } */ -/* { dg-options "-O -fstrict-overflow -fdump-tree-empty" } */ +/* { dg-options "-O2 -fstrict-overflow -fdump-tree-optimized" } */ void foo(int a, int b) { for(;a!=b;a+=4); } @@ -13,5 +13,5 @@ void foo3(int*a, int* b) void foo4(int*a, int*b) { for(;a!=b;a++); } -/* { dg-final { scan-tree-dump-times "Removing empty loop" 4 "empty" } } */ -/* { dg-final { cleanup-tree-dump "empty" } } */ +/* { dg-final { scan-tree-dump-not "if" "optimized" } } */ +/* { dg-final { cleanup-tree-dump "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loop-25.c b/gcc/testsuite/gcc.dg/tree-ssa/loop-25.c index 75580c1f725..479ed81d970 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/loop-25.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/loop-25.c @@ -1,5 +1,5 @@ /* { dg-do compile } */ -/* { dg-options "-O2 -fdump-tree-profile" } */ +/* { dg-options "-O1 -fdump-tree-profile" } */ int foo(void); void bla(void); diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loop-26.c b/gcc/testsuite/gcc.dg/tree-ssa/loop-26.c index 5ebb3b1e1f7..f8bc8e010ae 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/loop-26.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/loop-26.c @@ -2,7 +2,7 @@ determine number of iterations of the following loops unconditionally. */ /* { dg-do compile } */ -/* { dg-options "-O -fstrict-overflow -fdump-tree-empty" } */ +/* { dg-options "-O2 -fstrict-overflow -fdump-tree-optimized-blocks" } */ unsigned foo(unsigned int n) { @@ -25,5 +25,5 @@ int foo0(int i0, int i1) return j; } -/* { dg-final { scan-tree-dump-times "Removing empty loop" 2 "empty" } } */ -/* { dg-final { cleanup-tree-dump "empty" } } */ +/* { dg-final { scan-tree-dump-times "if" 2 "optimized" } } */ +/* { dg-final { cleanup-tree-dump "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loop-29.c b/gcc/testsuite/gcc.dg/tree-ssa/loop-29.c index 13699aafd62..c900dbf9bfb 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/loop-29.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/loop-29.c @@ -1,7 +1,7 @@ /* PR 31885 */ /* { dg-do compile } */ -/* { dg-options "-O1 -fdump-tree-empty" } */ +/* { dg-options "-O2 -fdump-tree-optimized" } */ struct s { int *blah; @@ -17,5 +17,5 @@ foo (struct s *p) p++; } -/* { dg-final { scan-tree-dump-times "Removing empty loop" 1 "empty" } } */ -/* { dg-final { cleanup-tree-dump "empty" } } */ +/* { dg-final { scan-tree-dump-not "if" "optimized" } } */ +/* { dg-final { cleanup-tree-dump "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr32044.c b/gcc/testsuite/gcc.dg/tree-ssa/pr32044.c index 940a0362943..58a62662b4f 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/pr32044.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr32044.c @@ -1,5 +1,5 @@ /* { dg-do compile } */ -/* { dg-options "-O2 -fdump-tree-empty -fdump-tree-optimized" } */ +/* { dg-options "-O2 -fdump-tree-optimized" } */ int foo (int n) { @@ -43,13 +43,12 @@ int baz (int n) return i; } -/* The loops computing division/modulo by 64 should be eliminated. */ -/* { dg-final { scan-tree-dump-times "Removing empty loop" 2 "empty" } } */ +/* The loops computing division/modulo by 64 should be eliminated */ +/* { dg-final { scan-tree-dump-times "if" 6 "optimized" } } */ /* There should be no division/modulo in the final dump (division and modulo by 64 are done using bit operations). */ /* { dg-final { scan-tree-dump-times "/" 0 "optimized" } } */ /* { dg-final { scan-tree-dump-times "%" 0 "optimized" } } */ -/* { dg-final { cleanup-tree-dump "empty" } } */ /* { dg-final { cleanup-tree-dump "optimized" } } */ diff --git a/gcc/testsuite/gnat.dg/loop_optimization6.adb b/gcc/testsuite/gnat.dg/loop_optimization6.adb index 42f1717f1ad..7a0f6d38803 100644 --- a/gcc/testsuite/gnat.dg/loop_optimization6.adb +++ b/gcc/testsuite/gnat.dg/loop_optimization6.adb @@ -1,5 +1,5 @@ -- { dg-do compile } --- { dg-options "-O -gnatp -fdump-tree-optimized" } +-- { dg-options "-O2 -gnatp -fdump-tree-optimized" } package body Loop_Optimization6 is procedure Foo is diff --git a/gcc/tree-flow.h b/gcc/tree-flow.h index 1b654a088fd..8d9b393e56e 100644 --- a/gcc/tree-flow.h +++ b/gcc/tree-flow.h @@ -745,7 +745,6 @@ unsigned int tree_ssa_unswitch_loops (void); unsigned int canonicalize_induction_variables (void); unsigned int tree_unroll_loops_completely (bool, bool); unsigned int tree_ssa_prefetch_arrays (void); -unsigned int remove_empty_loops (void); void tree_ssa_iv_optimize (void); unsigned tree_predictive_commoning (void); tree canonicalize_loop_ivs (struct loop *, htab_t, tree *); diff --git a/gcc/tree-ssa-dce.c b/gcc/tree-ssa-dce.c index 1bb2adc6a37..fdfdda5e95f 100644 --- a/gcc/tree-ssa-dce.c +++ b/gcc/tree-ssa-dce.c @@ -434,17 +434,42 @@ find_obviously_necessary_stmts (struct edge_list *el) } } + /* Pure and const functions are finite and thus have no infinite loops in + them. */ + if ((TREE_READONLY (current_function_decl) + || DECL_PURE_P (current_function_decl)) + && !DECL_LOOPING_CONST_OR_PURE_P (current_function_decl)) + return; + + /* Prevent the empty possibly infinite loops from being removed. */ if (el) { - /* Prevent the loops from being removed. We must keep the infinite loops, - and we currently do not have a means to recognize the finite ones. */ - FOR_EACH_BB (bb) - { - edge_iterator ei; - FOR_EACH_EDGE (e, ei, bb->succs) - if (e->flags & EDGE_DFS_BACK) - mark_control_dependent_edges_necessary (e->dest, el); - } + loop_iterator li; + struct loop *loop; + scev_initialize (); + if (mark_irreducible_loops ()) + FOR_EACH_BB (bb) + { + edge_iterator ei; + FOR_EACH_EDGE (e, ei, bb->succs) + if ((e->flags & EDGE_DFS_BACK) + && (e->flags & EDGE_IRREDUCIBLE_LOOP)) + { + if (dump_file) + fprintf (dump_file, "Marking back edge of irreducible loop %i->%i\n", + e->src->index, e->dest->index); + mark_control_dependent_edges_necessary (e->dest, el); + } + } + + FOR_EACH_LOOP (li, loop, 0) + if (!finite_loop_p (loop)) + { + if (dump_file) + fprintf (dump_file, "can not prove finiteness of loop %i\n", loop->num); + mark_control_dependent_edges_necessary (loop->latch, el); + } + scev_finalize (); } } @@ -570,6 +595,19 @@ mark_all_reaching_defs_necessary (gimple stmt) mark_all_reaching_defs_necessary_1, NULL, &visited); } +/* Return true for PHI nodes with one or identical arguments + can be removed. */ +static bool +degenerate_phi_p (gimple phi) +{ + unsigned int i; + tree op = gimple_phi_arg_def (phi, 0); + for (i = 1; i < gimple_phi_num_args (phi); i++) + if (gimple_phi_arg_def (phi, i) != op) + return false; + return true; +} + /* Propagate necessity using the operands of necessary statements. Process the uses on each statement in the worklist, and add all feeding statements which contribute to the calculation of this @@ -632,7 +670,7 @@ propagate_necessity (struct edge_list *el) mark_operand_necessary (arg); } - if (aggressive) + if (aggressive && !degenerate_phi_p (stmt)) { for (k = 0; k < gimple_phi_num_args (stmt); k++) { @@ -822,23 +860,13 @@ remove_dead_phis (basic_block bb) very simple dead PHI removal here. */ if (!is_gimple_reg (gimple_phi_result (phi))) { - unsigned i; - tree vuse; - /* Virtual PHI nodes with one or identical arguments can be removed. */ - vuse = gimple_phi_arg_def (phi, 0); - for (i = 1; i < gimple_phi_num_args (phi); ++i) - { - if (gimple_phi_arg_def (phi, i) != vuse) - { - vuse = NULL_TREE; - break; - } - } - if (vuse != NULL_TREE) + if (degenerate_phi_p (phi)) { tree vdef = gimple_phi_result (phi); + tree vuse = gimple_phi_arg_def (phi, 0); + use_operand_p use_p; imm_use_iterator iter; gimple use_stmt; @@ -899,7 +927,7 @@ static edge forward_edge_to_pdom (edge e, basic_block post_dom_bb) { gimple_stmt_iterator gsi; - edge e2; + edge e2 = NULL; edge_iterator ei; if (dump_file && (dump_flags & TDF_DETAILS)) @@ -924,6 +952,7 @@ forward_edge_to_pdom (edge e, basic_block post_dom_bb) for (gsi = gsi_start_phis (post_dom_bb); !gsi_end_p (gsi);) { gimple phi = gsi_stmt (gsi); + tree op; /* Dead PHI do not imply control dependency. */ if (!gimple_plf (phi, STMT_NECESSARY) @@ -947,8 +976,12 @@ forward_edge_to_pdom (edge e, basic_block post_dom_bb) remove_phi_node (&gsi, true); continue; } - gcc_assert (e2); - add_phi_arg (phi, gimple_phi_arg_def (phi, e2->dest_idx), e); + if (!e2) + op = gimple_phi_arg_def (phi, e->dest_idx == 0 ? 1 : 0); + else + op = gimple_phi_arg_def (phi, e2->dest_idx); + add_phi_arg (phi, op, e); + gcc_assert (e2 || degenerate_phi_p (phi)); gsi_next (&gsi); } } @@ -1094,7 +1127,42 @@ eliminate_unnecessary_stmts (void) } } } - + /* Since we don't track liveness of virtual PHI nodes, it is possible that we + rendered some PHI nodes unreachable while they are still in use. + Mark them for renaming. */ + if (cfg_altered) + { + basic_block next_bb; + find_unreachable_blocks (); + for (bb = ENTRY_BLOCK_PTR->next_bb; bb != EXIT_BLOCK_PTR; bb = next_bb) + { + next_bb = bb->next_bb; + if (!(bb->flags & BB_REACHABLE)) + { + for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) + if (!is_gimple_reg (gimple_phi_result (gsi_stmt (gsi)))) + { + bool found = false; + imm_use_iterator iter; + + FOR_EACH_IMM_USE_STMT (stmt, iter, gimple_phi_result (gsi_stmt (gsi))) + { + if (!(gimple_bb (stmt)->flags & BB_REACHABLE)) + continue; + if (gimple_code (stmt) == GIMPLE_PHI + || gimple_plf (stmt, STMT_NECESSARY)) + { + found = true; + BREAK_FROM_IMM_USE_STMT (iter); + } + } + if (found) + mark_virtual_phi_result_for_renaming (gsi_stmt (gsi)); + } + delete_basic_block (bb); + } + } + } FOR_EACH_BB (bb) { /* Remove dead PHI nodes. */ @@ -1197,6 +1265,13 @@ perform_tree_ssa_dce (bool aggressive) struct edge_list *el = NULL; bool something_changed = 0; + /* Preheaders are needed for SCEV to work. + Simple lateches and recorded exits improve chances that loop will + proved to be finite in testcases such as in loop-15.c and loop-24.c */ + if (aggressive) + loop_optimizer_init (LOOPS_NORMAL + | LOOPS_HAVE_RECORDED_EXITS); + tree_dce_init (aggressive); if (aggressive) @@ -1216,6 +1291,9 @@ perform_tree_ssa_dce (bool aggressive) find_obviously_necessary_stmts (el); + if (aggressive) + loop_optimizer_finalize (); + longest_chain = 0; total_chain = 0; chain_ovfl = false; diff --git a/gcc/tree-ssa-loop-ivcanon.c b/gcc/tree-ssa-loop-ivcanon.c index 8e45bbb97e6..a04466a4027 100644 --- a/gcc/tree-ssa-loop-ivcanon.c +++ b/gcc/tree-ssa-loop-ivcanon.c @@ -558,187 +558,3 @@ tree_unroll_loops_completely (bool may_increase_size, bool unroll_outer) return 0; } - -/* Checks whether LOOP is empty. */ - -static bool -empty_loop_p (struct loop *loop) -{ - edge exit; - basic_block *body; - gimple_stmt_iterator gsi; - unsigned i; - - /* If the loop has multiple exits, it is too hard for us to handle. - Similarly, if the exit is not dominating, we cannot determine - whether the loop is not infinite. */ - exit = single_dom_exit (loop); - if (!exit) - return false; - - /* The loop must be finite. */ - if (!finite_loop_p (loop)) - return false; - - /* Values of all loop exit phi nodes must be invariants. */ - for (gsi = gsi_start(phi_nodes (exit->dest)); !gsi_end_p (gsi); gsi_next (&gsi)) - { - gimple phi = gsi_stmt (gsi); - tree def; - - if (!is_gimple_reg (PHI_RESULT (phi))) - continue; - - def = PHI_ARG_DEF_FROM_EDGE (phi, exit); - - if (!expr_invariant_in_loop_p (loop, def)) - return false; - } - - /* And there should be no memory modifying or from other reasons - unremovable statements. */ - body = get_loop_body (loop); - for (i = 0; i < loop->num_nodes; i++) - { - /* Irreducible region might be infinite. */ - if (body[i]->flags & BB_IRREDUCIBLE_LOOP) - { - free (body); - return false; - } - - for (gsi = gsi_start_bb (body[i]); !gsi_end_p (gsi); gsi_next (&gsi)) - { - gimple stmt = gsi_stmt (gsi); - - if (gimple_vdef (stmt) - || gimple_has_volatile_ops (stmt)) - { - free (body); - return false; - } - - /* Also, asm statements and calls may have side effects and we - cannot change the number of times they are executed. */ - switch (gimple_code (stmt)) - { - case GIMPLE_CALL: - if (gimple_has_side_effects (stmt)) - { - free (body); - return false; - } - break; - - case GIMPLE_ASM: - /* We cannot remove volatile assembler. */ - if (gimple_asm_volatile_p (stmt)) - { - free (body); - return false; - } - break; - - default: - break; - } - } - } - free (body); - - return true; -} - -/* Remove LOOP by making it exit in the first iteration. */ - -static void -remove_empty_loop (struct loop *loop) -{ - edge exit = single_dom_exit (loop), non_exit; - gimple cond_stmt = last_stmt (exit->src); - basic_block *body; - unsigned n_before, freq_in, freq_h; - gcov_type exit_count = exit->count; - - if (dump_file) - fprintf (dump_file, "Removing empty loop %d\n", loop->num); - - non_exit = EDGE_SUCC (exit->src, 0); - if (non_exit == exit) - non_exit = EDGE_SUCC (exit->src, 1); - - if (exit->flags & EDGE_TRUE_VALUE) - gimple_cond_make_true (cond_stmt); - else - gimple_cond_make_false (cond_stmt); - update_stmt (cond_stmt); - - /* Let us set the probabilities of the edges coming from the exit block. */ - exit->probability = REG_BR_PROB_BASE; - non_exit->probability = 0; - non_exit->count = 0; - - /* Update frequencies and counts. Everything before - the exit needs to be scaled FREQ_IN/FREQ_H times, - where FREQ_IN is the frequency of the entry edge - and FREQ_H is the frequency of the loop header. - Everything after the exit has zero frequency. */ - freq_h = loop->header->frequency; - freq_in = EDGE_FREQUENCY (loop_preheader_edge (loop)); - if (freq_h != 0) - { - body = get_loop_body_in_dom_order (loop); - for (n_before = 1; n_before <= loop->num_nodes; n_before++) - if (body[n_before - 1] == exit->src) - break; - scale_bbs_frequencies_int (body, n_before, freq_in, freq_h); - scale_bbs_frequencies_int (body + n_before, loop->num_nodes - n_before, - 0, 1); - free (body); - } - - /* Number of executions of exit is not changed, thus we need to restore - the original value. */ - exit->count = exit_count; -} - -/* Removes LOOP if it is empty. Returns true if LOOP is removed. CHANGED - is set to true if LOOP or any of its subloops is removed. */ - -static bool -try_remove_empty_loop (struct loop *loop, bool *changed) -{ - bool nonempty_subloop = false; - struct loop *sub; - - /* First, all subloops must be removed. */ - for (sub = loop->inner; sub; sub = sub->next) - nonempty_subloop |= !try_remove_empty_loop (sub, changed); - - if (nonempty_subloop || !empty_loop_p (loop)) - return false; - - remove_empty_loop (loop); - *changed = true; - return true; -} - -/* Remove the empty loops. */ - -unsigned int -remove_empty_loops (void) -{ - bool changed = false; - struct loop *loop; - - for (loop = current_loops->tree_root->inner; loop; loop = loop->next) - try_remove_empty_loop (loop, &changed); - - if (changed) - { - scev_reset (); - return TODO_cleanup_cfg; - } - return 0; -} - diff --git a/gcc/tree-ssa-loop.c b/gcc/tree-ssa-loop.c index 33cb130e4ca..4dcdc02d2d6 100644 --- a/gcc/tree-ssa-loop.c +++ b/gcc/tree-ssa-loop.c @@ -433,37 +433,6 @@ struct gimple_opt_pass pass_scev_cprop = } }; -/* Remove empty loops. */ - -static unsigned int -tree_ssa_empty_loop (void) -{ - if (number_of_loops () <= 1) - return 0; - - return remove_empty_loops (); -} - -struct gimple_opt_pass pass_empty_loop = -{ - { - GIMPLE_PASS, - "empty", /* name */ - NULL, /* gate */ - tree_ssa_empty_loop, /* execute */ - NULL, /* sub */ - NULL, /* next */ - 0, /* static_pass_number */ - TV_COMPLETE_UNROLL, /* tv_id */ - PROP_cfg | PROP_ssa, /* properties_required */ - 0, /* properties_provided */ - 0, /* properties_destroyed */ - 0, /* todo_flags_start */ - TODO_dump_func | TODO_verify_loops - | TODO_ggc_collect /* todo_flags_finish */ - } -}; - /* Record bounds on numbers of iterations of loops. */ static unsigned int |