From a6b3b25c2899cc3130325bea05dcd14e227ec876 Mon Sep 17 00:00:00 2001 From: hubicka Date: Mon, 15 Jan 2007 15:44:51 +0000 Subject: [PATCH] * tree-ssa-dce.c (DCE_TODOs): New. (propagate_necessity): Return if something changed. (eliminate_unnecessary_stmts): Likewise. (perform_tree_ssa_dce): Return TODO flags when needed. (pass_dce, pass_dce_loop, pass_cd_dce): Remove TODO flags. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@120797 138bc75d-0d04-0410-961f-82ee72b054a4 --- gcc/ChangeLog | 8 +++++++ gcc/tree-ssa-dce.c | 68 +++++++++++++++++++++++++++++------------------------- 2 files changed, 45 insertions(+), 31 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 820c45c55c3..99c9b5744ce 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2007-01-15 Jan Hubicka + + * tree-ssa-dce.c (DCE_TODOs): New. + (propagate_necessity): Return if something changed. + (eliminate_unnecessary_stmts): Likewise. + (perform_tree_ssa_dce): Return TODO flags when needed. + (pass_dce, pass_dce_loop, pass_cd_dce): Remove TODO flags. + 2007-01-15 Uros Bizjak * config/i386/i386.md (fyl2xxf3_i387): Rename from fyl2x_xf3. diff --git a/gcc/tree-ssa-dce.c b/gcc/tree-ssa-dce.c index a26b87f5d8e..381d91016e0 100644 --- a/gcc/tree-ssa-dce.c +++ b/gcc/tree-ssa-dce.c @@ -525,10 +525,11 @@ propagate_necessity (struct edge_list *el) /* Remove dead PHI nodes from block BB. */ -static void +static bool remove_dead_phis (basic_block bb) { tree prev, phi; + bool something_changed = false; prev = NULL_TREE; phi = phi_nodes (bb); @@ -540,6 +541,7 @@ remove_dead_phis (basic_block bb) { tree next = PHI_CHAIN (phi); + something_changed = true; if (dump_file && (dump_flags & TDF_DETAILS)) { fprintf (dump_file, "Deleting : "); @@ -557,6 +559,7 @@ remove_dead_phis (basic_block bb) phi = PHI_CHAIN (phi); } } + return something_changed; } @@ -649,9 +652,10 @@ remove_dead_stmt (block_stmt_iterator *i, basic_block bb) /* Eliminate unnecessary statements. Any instruction not marked as necessary contributes nothing to the program, and can be deleted. */ -static void +static bool eliminate_unnecessary_stmts (void) { + bool something_changed = false; basic_block bb; block_stmt_iterator i; @@ -662,7 +666,7 @@ eliminate_unnecessary_stmts (void) FOR_EACH_BB (bb) { /* Remove dead PHI nodes. */ - remove_dead_phis (bb); + something_changed |= remove_dead_phis (bb); } FOR_EACH_BB (bb) @@ -676,7 +680,10 @@ eliminate_unnecessary_stmts (void) /* If `i' is not necessary then remove it. */ if (! NECESSARY (t)) - remove_dead_stmt (&i, bb); + { + remove_dead_stmt (&i, bb); + something_changed = true; + } else { tree call = get_call_expr_in (t); @@ -686,6 +693,7 @@ eliminate_unnecessary_stmts (void) } } } + return something_changed; } @@ -774,10 +782,11 @@ tree_dce_done (bool aggressive) as the last tree SSA pass, but keep this in mind when you start experimenting with pass ordering. */ -static void +static unsigned int perform_tree_ssa_dce (bool aggressive) { struct edge_list *el = NULL; + bool something_changed = 0; tree_dce_init (aggressive); @@ -800,9 +809,10 @@ perform_tree_ssa_dce (bool aggressive) propagate_necessity (el); - eliminate_unnecessary_stmts (); + something_changed |= eliminate_unnecessary_stmts (); + something_changed |= cfg_altered; - if (aggressive) + if (aggressive && something_changed) free_dominance_info (CDI_POST_DOMINATORS); /* If we removed paths in the CFG, then we need to update @@ -818,30 +828,38 @@ perform_tree_ssa_dce (bool aggressive) tree_dce_done (aggressive); free_edge_list (el); + + if (something_changed) + return (TODO_update_ssa | TODO_cleanup_cfg | TODO_ggc_collect + | TODO_remove_unused_locals); + else + return 0; } /* Pass entry points. */ static unsigned int tree_ssa_dce (void) { - perform_tree_ssa_dce (/*aggressive=*/false); - return 0; + return perform_tree_ssa_dce (/*aggressive=*/false); } static unsigned int tree_ssa_dce_loop (void) { - perform_tree_ssa_dce (/*aggressive=*/false); - free_numbers_of_iterations_estimates (); - scev_reset (); - return 0; + unsigned int todo; + todo = perform_tree_ssa_dce (/*aggressive=*/false); + if (todo) + { + free_numbers_of_iterations_estimates (); + scev_reset (); + } + return todo; } static unsigned int tree_ssa_cd_dce (void) { - perform_tree_ssa_dce (/*aggressive=*/optimize >= 2); - return 0; + return perform_tree_ssa_dce (/*aggressive=*/optimize >= 2); } static bool @@ -863,12 +881,7 @@ struct tree_opt_pass pass_dce = 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ - TODO_dump_func - | TODO_update_ssa - | TODO_cleanup_cfg - | TODO_ggc_collect - | TODO_verify_ssa - | TODO_remove_unused_locals, /* todo_flags_finish */ + TODO_dump_func | TODO_verify_ssa, /* todo_flags_finish */ 0 /* letter */ }; @@ -885,10 +898,7 @@ struct tree_opt_pass pass_dce_loop = 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ - TODO_dump_func - | TODO_update_ssa - | TODO_cleanup_cfg - | TODO_verify_ssa, /* todo_flags_finish */ + TODO_dump_func | TODO_verify_ssa, /* todo_flags_finish */ 0 /* letter */ }; @@ -905,11 +915,7 @@ struct tree_opt_pass pass_cd_dce = 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ - TODO_dump_func - | TODO_update_ssa - | TODO_cleanup_cfg - | TODO_ggc_collect - | TODO_verify_ssa - | TODO_verify_flow, /* todo_flags_finish */ + TODO_dump_func | TODO_verify_ssa + | TODO_verify_flow, /* todo_flags_finish */ 0 /* letter */ }; -- 2.11.4.GIT