From 9fb32434113c28e3f8f2346be2609a4f6fd136ea Mon Sep 17 00:00:00 2001 From: Caroline Tice Date: Wed, 18 Aug 2004 09:22:08 -0700 Subject: Hot/cold partitioning update patch. Hot/cold partitioning update patch. The problems that this patch attemptd to address/fix are: - Fix places where adding in_unlikely_executed_text to the enum data type "in_section" threw off switch case statements. - Make it work correctly (by turning it off) for functions where user specifies "__attribute__ section" - Make it work correctly (by turning it off) for linkonce sections - Make it work correctly with -ffunction-sections flag - Make it output correct cold section labels - Undo some changes to original assembly code generation - Turn off hot/cold partitioning in the presence of DWARF debugging (for the moment) - Turn off hot/cold partitioning for architectures that do not support named sections - Use variables rather than constants for cold section labels and names (to work correctly with -ffunction-sections, among other things) 2004-08-18 Caroline Tice * Makefile.in (STAGEFEEDBACK_FLAGS_TO_PASS) Add "-freorder-blocks-and-partition" to the flags used in second stage of profiledbootstrap. * bb-reorder.c (push_to_next_round_p): Add new variable, next_round_is_last; set and use variable to make sure, when partitioning, that the last trace construction round consists of all (and only) cold basic blocks. (rotate_loop): Don't copy blocks that end in a section crossing jump. (copy_bb): Correctly initialize "partition" of duplicated bb. (add_unlikely_executed_notes): Add a comment. (find_rarely_executed_basic_blocks_and_crossing_edges): Modify to make sure, if function contains hot blocks, that the successors of ENTRY_BLOCK_PTR are hot; also, only look for crossing edges if the architecture supports named sections. (mark_bb_for_unlikely_executed_section): Modify to always insert the NOTE_INSN_UNLIKELY_EXECUTED_CODE immediately after the basic block note insn. (fix_crossing_unconditional_branches): Remove extra space. (fix_edges_for_rarely_executed_code): Modify to only do partitioning work if the architecture supports named sections. (reorder_basic_blocks): Modify to only add NOTE_INSN_UNLIKELY_EXECUTED_CODE notes if the architecture supports named sections. * c-common.c (handle_section_attribute): Initialize new global variable, user_defined_section_attribute, to true if user has specified one. * cfgcleanup.c (try_forward_edges): Modify to not attempt to forward edges that cross section boundaries. * cfglayout.c (fixup_reorder_chain): Modify to only fix up partitioning information if the architecture supports named sections. * cfgrtl.c (target.h): Add statement to include this. (rtl_split_block): Make sure newly created bb gets correct partition. (try_redirect_by_replacing_jump): Make sure redirection isn't attempting to cross section boundaries. (force_nonfallthru_and_redirect): Only do partition fix up if architecture supports named sections. (rtl_split_edge): Make sure newly created bb ends up in correct partition. (commit_one_edge_insertion): Remove code that incorrectly updated basic block partition; Make sure partition fix up only happens if architecture supports named sections and it's not already done. (rtl_verify_flow_info_1): Fix if-condition on test/error condition that fallthru edges are not allowed to cross section boundaries. * defaults.h (NORMAL_TEXT_SECTION_NAME): Remove this. * final.c (final_scan_insn): Remove redundant test from if-statement; change calls to text_section into calls to function_section; add code to only to partitioning fix up if architecture supports named sections. * ifcvt.c (find_if_case_1): Make sure newly created bb has correct partition. (if_convert): Add targetm.have_named_sections to test. * output.h (unlikely_section_label): Extern declaration for new global variable. (unlikely_text_section_name): Likewise. * opts.c (decode_options): If both partitioning and DWARF debugging are turned on, issue a warning that this doesn't work, and change partitiong to basic block reordering (without hot/cold partitions). * passes.c (rest_of_handle_final): Re-set new global variable, user_defined_section_attribute, to false. (rest_of_compilation): Change options for calling partitioning function: Don't call if the user defined the section attribute, and don't call if DECL_ONE_ONLY is true for the current function. * predict.c (choose_function_section): Return immediately if we are doing hot/cold partitioning (i.e. let the basic block partitioning determine where the function belongs). * reg-stack.c (emit_swap_insn): Add condition to step over NOTE_INSN_UNLIKELY_EXECUTED_CODE notes. * toplev.c (user_defined_section_attribute): New global variable. * toplev.h (user_defined_section_attribute): Extern declaration for new global variable. * varasm.c (unlikely_section_label): New global variable. (unlikely_text_section_name): New global variable. (unlikely_text_section): Add code to initialize unlikely_text_section_name if necessary; modify to use unlikely_text_section_name and unlikely_section_label; also to use named_section properly. (in_unlikely_text_section): Modify to work correctly with named_section and to use unlikely_text_section_name. (named_section): Add code to work properly with cold section. (function_section): Clean up if-statement. * config/darwin.c (darwin_asm_named_section): Return to original code, removing use of SECTION_FORMAT_STRING. * config/arm/pe.h (switch_to_section): Add case for in_unlikely_executed_text to switch statement. * config/i386/cygming.h (switch_to_section): Likewise. * config/i386/darwin.h (NORMAL_TEXT_SECTION_NAME): Remove. (SECTION_FORMAT_STRING): Likewise. * config/mcore/mcore.h (switch_to_section): Likewise. * config/rs6000/darwin.h (NORMAL_TEXT_SECTION_NAME): Remove. From-SVN: r86189 --- gcc/opts.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'gcc/opts.c') diff --git a/gcc/opts.c b/gcc/opts.c index 01297b0..a6a7c33 100644 --- a/gcc/opts.c +++ b/gcc/opts.c @@ -641,6 +641,21 @@ decode_options (unsigned int argc, const char **argv) flag_reorder_blocks_and_partition = 0; flag_reorder_blocks = 1; } + + /* The optimization to partition hot and cold basic blocks into + separate sections of the .o and executable files does not currently + work correctly with DWARF debugging turned on. Until this is fixed + we will disable the optimization when DWARF debugging is set. */ + + if (flag_reorder_blocks_and_partition + && (write_symbols == DWARF_DEBUG + || write_symbols == DWARF2_DEBUG)) + { + warning + ("-freorder-blocks-and-partition does not work with -g (currently)"); + flag_reorder_blocks_and_partition = 0; + flag_reorder_blocks = 1; + } } /* Handle target- and language-independent options. Return zero to -- cgit v1.1