From 59faab7cc48681d8b2c995bdc466e1f3262839fa Mon Sep 17 00:00:00 2001 From: Segher Boessenkool Date: Thu, 1 Oct 2015 08:38:24 +0200 Subject: [PATCH] bb-reorder: Add -freorder-blocks-algorithm= and wire it up This adds an -freorder-blocks-algorithm=[simple|stc] flag, with "simple" as default. For -O2 and up (except -Os) it is switched to "stc" instead. Targets that never want STC can override this. This changes -freorder-blocks to be on at -O1 and up (was -O2 and up). In effect, the changes are for -O1 (which now gets "simple" instead of nothing), -Os (which now gets "simple" instead of "stc", since STC results in much bigger code), and for targets that wish to never use STC (not in this patch though). 2015-09-23 Segher Boessenkool * bb-reorder.c (reorder_basic_blocks): Use the algorithm selected with flag_reorder_blocks_algorithm. * common.opt (freorder-blocks-algorithm=): New flag. (reorder_blocks_algorithm): New enum. * flag-types.h (reorder_blocks_algorithm): New enum. * opts.c (default_options_table): Use -freorder-blocks at -O1 and up, and -freorder-blocks-algorithm=stc at -O2 and up (not at -Os). From-SVN: r228318 --- gcc/ChangeLog | 10 ++++++++++ gcc/bb-reorder.c | 17 +++++++++++++---- gcc/common.opt | 13 +++++++++++++ gcc/flag-types.h | 7 +++++++ gcc/opts.c | 4 +++- 5 files changed, 46 insertions(+), 5 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 92fcb0febe5..8bfff2b106f 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,13 @@ +2015-10-01 Segher Boessenkool + + * bb-reorder.c (reorder_basic_blocks): Use the algorithm selected + with flag_reorder_blocks_algorithm. + * common.opt (freorder-blocks-algorithm=): New flag. + (reorder_blocks_algorithm): New enum. + * flag-types.h (reorder_blocks_algorithm): New enum. + * opts.c (default_options_table): Use -freorder-blocks at -O1 and up, + and -freorder-blocks-algorithm=stc at -O2 and up (not at -Os). + 2015-10-01 Segher Boessenkool * bb-reorder.c: Add intro comment. diff --git a/gcc/bb-reorder.c b/gcc/bb-reorder.c index 4d07b2e1369..cb001e89f21 100644 --- a/gcc/bb-reorder.c +++ b/gcc/bb-reorder.c @@ -2444,10 +2444,19 @@ reorder_basic_blocks (void) set_edge_can_fallthru_flag (); mark_dfs_back_edges (); - if (1) - reorder_basic_blocks_software_trace_cache (); - else - reorder_basic_blocks_simple (); + switch (flag_reorder_blocks_algorithm) + { + case REORDER_BLOCKS_ALGORITHM_SIMPLE: + reorder_basic_blocks_simple (); + break; + + case REORDER_BLOCKS_ALGORITHM_STC: + reorder_basic_blocks_software_trace_cache (); + break; + + default: + gcc_unreachable (); + } relink_block_chain (/*stay_in_cfglayout_mode=*/true); diff --git a/gcc/common.opt b/gcc/common.opt index 94d1d884833..b0f70fb4e9e 100644 --- a/gcc/common.opt +++ b/gcc/common.opt @@ -1910,6 +1910,19 @@ freorder-blocks Common Report Var(flag_reorder_blocks) Optimization Reorder basic blocks to improve code placement +freorder-blocks-algorithm= +Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization +-freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm + +Enum +Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs) + +EnumValue +Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE) + +EnumValue +Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC) + freorder-blocks-and-partition Common Report Var(flag_reorder_blocks_and_partition) Optimization Reorder basic blocks and partition into hot and cold sections diff --git a/gcc/flag-types.h b/gcc/flag-types.h index ac9ca0b75e0..6301cea4807 100644 --- a/gcc/flag-types.h +++ b/gcc/flag-types.h @@ -109,6 +109,13 @@ enum stack_reuse_level SR_ALL }; +/* The algorithm used for basic block reordering. */ +enum reorder_blocks_algorithm +{ + REORDER_BLOCKS_ALGORITHM_SIMPLE, + REORDER_BLOCKS_ALGORITHM_STC +}; + /* The algorithm used for the integrated register allocator (IRA). */ enum ira_algorithm { diff --git a/gcc/opts.c b/gcc/opts.c index 2bbf6534077..896875b40e4 100644 --- a/gcc/opts.c +++ b/gcc/opts.c @@ -441,6 +441,7 @@ static const struct default_options default_options_table[] = { OPT_LEVELS_1_PLUS, OPT_fipa_reference, NULL, 1 }, { OPT_LEVELS_1_PLUS, OPT_fipa_profile, NULL, 1 }, { OPT_LEVELS_1_PLUS, OPT_fmerge_constants, NULL, 1 }, + { OPT_LEVELS_1_PLUS, OPT_freorder_blocks, NULL, 1 }, { OPT_LEVELS_1_PLUS, OPT_fshrink_wrap, NULL, 1 }, { OPT_LEVELS_1_PLUS, OPT_fsplit_wide_types, NULL, 1 }, { OPT_LEVELS_1_PLUS, OPT_ftree_ccp, NULL, 1 }, @@ -483,7 +484,8 @@ static const struct default_options default_options_table[] = #endif { OPT_LEVELS_2_PLUS, OPT_fstrict_aliasing, NULL, 1 }, { OPT_LEVELS_2_PLUS, OPT_fstrict_overflow, NULL, 1 }, - { OPT_LEVELS_2_PLUS, OPT_freorder_blocks, NULL, 1 }, + { OPT_LEVELS_2_PLUS_SPEED_ONLY, OPT_freorder_blocks_algorithm_, NULL, + REORDER_BLOCKS_ALGORITHM_STC }, { OPT_LEVELS_2_PLUS, OPT_freorder_functions, NULL, 1 }, { OPT_LEVELS_2_PLUS, OPT_ftree_vrp, NULL, 1 }, { OPT_LEVELS_2_PLUS, OPT_ftree_builtin_call_dce, NULL, 1 }, -- 2.30.2