Regression in GCC4.5.0 m68k-elf with r146817 (Author: matz)

Regression in GCC4.5.0 m68k-elf with r146817 (Author: matz)

[Bernd Roesch]

Hi, 

http://gcc.gnu.org/ml/gcc-cvs/2009-04/msg01459.html

This do the problem when compile ffmpeg.all gcc Versions that contain the
Patch fail 

-m68020 -m68881 -O1 ("Abort trap")

but work when do 

-m68020 -m68881 -O1 -fno-tree-ccp -fno-tree-dominator-opts (works ok).

.See here for more about the Problem.(the testprogram that show what code is
execute is also add)

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41311

In a testprogram i cant reproduce the Problem, seem only happen on special
register usage.It seem have nothing to do with the backend.

But whats the line that fail i cant find out, because there are too many
changes at once in the Patch.

maybe somebody can help me so i can reproduce the problem better or add log
output for GCC in this special functions ?

Here is the changelog of the Patch

"""
2009-04-26  Michael Matz  

    Expand from SSA.
    * builtins.c (fold_builtin_next_arg): Handle SSA names.
    * tree-ssa-copyrename.c (rename_ssa_copies): Use ssa_name() directly.
    * tree-ssa-coalesce.c (create_outofssa_var_map): Mark only useful
    SSA names. 
    (compare_pairs): Swap cost comparison.
    (coalesce_ssa_name): Don't use change_partition_var.
    * tree-nrv.c (struct nrv_data): Add modified member.
    (finalize_nrv_r): Set it.
    (tree_nrv): Use it to update statements.
    (pass_nrv): Require PROP_ssa.
    * tree-mudflap.c (mf_decl_cache_locals,
    mf_build_check_statement_for): Use make_rename_temp.
    (pass_mudflap_2): Require PROP_ssa, run ssa update at finish.
    * alias.c (find_base_decl): Handle SSA names.
    * emit-rtl (set_reg_attrs_for_parm): Make non-static.
    (component_ref_for_mem_expr): Don't leak SSA names into RTL.
    * rtl.h (set_reg_attrs_for_parm): Declare.
    * tree-optimize.c (pass_cleanup_cfg_post_optimizing): Rename
    to "optimized", remove unused locals at finish.
    (execute_free_datastructures): Make global, call
    delete_tree_cfg_annotations.
    (execute_free_cfg_annotations): Don't call
    delete_tree_cfg_annotations.

    * ssaexpand.h: New file.
    * expr.c (toplevel): Include ssaexpand.h.
    (expand_assignment): Handle SSA names the same as register
    variables.
    (expand_expr_real_1): Expand SSA names.
    * cfgexpand.c (toplevel): Include ssaexpand.h.
    (SA): New global variable.
    (gimple_cond_pred_to_tree): Fold TERed comparisons into predicates.
    (SSAVAR): New macro.
    (set_rtl): New helper function.
    (add_stack_var): Deal with SSA names, use set_rtl.
    (expand_one_stack_var_at): Likewise.
    (expand_one_stack_var): Deal with SSA names.
    (stack_var_size_cmp): Use code (SSA_NAME / DECL) as tie breaker
    before unique numbers.
    (expand_stack_vars): Use set_rtl.
    (expand_one_var): Accept SSA names, add asserts for them, feed them
    to above subroutines.
    (expand_used_vars): Expand all partitions (without default defs),
    then only the local decls (ignoring those expanded already).
    (expand_gimple_cond): Remove edges when jumpif() expands an
    unconditional jump.
    (expand_gimple_basic_block): Don't clear EDGE_EXECUTABLE here,
    or remove abnormal edges.  Ignore insns setting the LHS of a TERed
    SSA name.
    (gimple_expand_cfg): Call into rewrite_out_of_ssa, initialize
    members of SA; deal with PARM_DECL partitions here; expand
    all PHI nodes, free tree datastructures and SA.  Commit instructions
    on edges, clear EDGE_EXECUTABLE and remove abnormal edges here.
    (pass_expand): Require and destroy PROP_ssa, verify SSA form, flow
    info and statements at start, collect garbage at finish.
    * tree-ssa-live.h (struct _var_map): Remove partition_to_var member.
    (VAR_ANN_PARTITION) Remove.
    (change_partition_var): Don't declare.
    (partition_to_var): Always return SSA names.
    (var_to_partition): Only accept SSA names.
    (register_ssa_partition): Only check argument.
    * tree-ssa-live.c (init_var_map): Don't allocate partition_to_var
    member.
    (delete_var_map): Don't free it.
    (var_union): Only accept SSA names, simplify.
    (partition_view_init): Mark only useful SSA names as used.
    (partition_view_fini): Only deal with SSA names.
    (change_partition_var): Remove.
    (dump_var_map): Use ssa_name instead of partition_to_var member.
    * tree-ssa.c (delete_tree_ssa): Don't remove PHI nodes on RTL
    basic blocks.
    * tree-outof-ssa.c (toplevel): Include ssaexpand.h and expr.h.
    (struct _elim_graph): New member const_dests; nodes member vector of
    ints.
    (set_location_for_edge): New static helper.
    (create_temp): Remove.
    (insert_partition_copy_on_edge, insert_part_to_rtx_on_edge,
    insert_value_copy_on_edge, insert_rtx_to_part_on_edge): New
    functions.
    (new_elim_graph): Allocate const_dests member.
    (clean_elim_graph): Truncate const_dests member.
    (delete_elim_graph): Free const_dests member.
    (elim_graph_size): Adapt to new type of nodes member.
    (elim_graph_add_node): Likewise.
    (eliminate_name): Likewise.
    (eliminate_build): Don't take basic block argument, deal only with
    partition numbers, not variables.
    (get_temp_reg): New static helper.
    (elim_create): Use it, deal with RTL temporaries instead of trees.
    (eliminate_phi): Adjust all calls to new signature.
    (assign_vars, replace_use_variable, replace_def_variable): Remove.
    (rewrite_trees): Only do checking.
    (edge_leader, stmt_list, leader_has_match, leader_match): Remove.
    (same_stmt_list_p, identical_copies_p, identical_stmt_lists_p,
    init_analyze_edges_for_bb, fini_analyze_edges_for_bb,
    contains_tree_r, MAX_STMTS_IN_LATCH,
    process_single_block_loop_latch, analyze_edges_for_bb,
    perform_edge_inserts): Remove.
    (expand_phi_nodes): New global function.
    (remove_ssa_form): Take ssaexpand parameter.  Don't call removed
    functions, initialize new parameter, remember partitions having a
    default def.
    (finish_out_of_ssa): New global function.
    (rewrite_out_of_ssa): Make global.  Adjust call to remove_ssa_form,
    don't reset in_ssa_p here, don't disable TER when mudflap.
    (pass_del_ssa): Remove.
    * tree-flow.h (struct var_ann_d): Remove out_of_ssa_tag and
    partition members.
    (execute_free_datastructures): Declare.
    * Makefile.in (SSAEXPAND_H): New variable.
    (tree-outof-ssa.o, expr.o, cfgexpand.o): Depend on SSAEXPAND_H.
    * basic-block.h (commit_one_edge_insertion): Declare.
    * passes.c (init_optimization_passes): Move pass_nrv and
    pass_mudflap2 before pass_cleanup_cfg_post_optimizing, remove
    pass_del_ssa, pass_free_datastructures, pass_free_cfg_annotations.
    * cfgrtl.c (commit_one_edge_insertion): Make global, don't declare.
    (redirect_branch_edge): Deal with super block when expanding, split
    out jump patching itself into ...
    (patch_jump_insn): ... here, new static helper.
""""

Bye