On Mon, Nov 26, 2012 at 12:19:55PM -0800, Teresa Johnson wrote:
> Are you sure you have all my changes applied? I applied the 4 patches
> attached to PR55121 into my trunk checkout that has my fixes, and to a
> pristine trunk checkout. I configured and built both for
> --target=arm-none-linux-gnueabi, and built using your options, .i file
> and gcda file. I can reproduce the failure using the pristine trunk
> with your patches but not with my fixed trunk + your patches. (I just
> updated to head to pickup recent changes and get the same result. The
> vec changes required some manual changes to the patch, which I will
> resend shortly.)
Teresa,
Your mailer seems to have corrupted the posted patch with stray
=3D characters and line breaks. Can you repost a copy as an attachment
to the list?
Jack
>
> Without my fixes:
>
> $ ~/extra/gcc_trunk_3_arm-eabi/gcc/cc1 -fpreproce
> ssed eval.i -quiet -dumpbase eval.c -march=armv7-a -mtune=cortex-a9
> -mthumb -mfpu=neon -mvectorize-with-neon-quad -mfloat-abi=softfp
> -mtls-dialect=gnu -auxbase-strip eval.o -g -O3 -version -fprofile-use
> -fno-common -o eval.s -freorder-blocks-and-partition
> GNU C (GCC) version 4.8.0 20121126 (experimental) (arm-none-linux-gnueabi)
> compiled by GNU C version 4.4.3, GMP version 4.3.2, MPFR version
> 2.4.2-p1, MPC version 0.8.1
> GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
> GNU C (GCC) version 4.8.0 20121126 (experimental) (arm-none-linux-gnueabi)
> compiled by GNU C version 4.4.3, GMP version 4.3.2, MPFR version
> 2.4.2-p1, MPC version 0.8.1
> GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
> Compiler executable checksum: d19cc60a2f07de08237a8488bb35cd1a
> eval.c: In function ‘Ge’:
> eval.c:792:1: internal compiler error: in df_compact_blocks, at df-core.c:1560
> }
> ^
> 0x622f71 df_compact_blocks()
> ../../gcc_trunk_3/gcc/df-core.c:1560
> 0x5cfcb5 compact_blocks()
> ../../gcc_trunk_3/gcc/cfg.c:162
> 0xc9dce0 reorder_basic_blocks
> ../../gcc_trunk_3/gcc/bb-reorder.c:2154
> 0xc9dce0 rest_of_handle_reorder_blocks
> ../../gcc_trunk_3/gcc/bb-reorder.c:2219
> Please submit a full bug report,
> with preprocessed source if appropriate.
> Please include the complete backtrace with any bug report.
> See <http://gcc.gnu.org/bugs.html> for instructions.
>
>
> With my fixes:
>
> $ ~/extra/gcc_trunk_4_arm-eabi/gcc/cc1 -fpreproce
> ssed eval.i -quiet -dumpbase eval.c -march=armv7-a -mtune=cortex-a9
> -mthumb -mfpu=neon -mvectorize-with-neon-quad -mfloat-abi=softfp
> -mtls-dialect=gnu -auxbase-strip eval.o -g -O3 -version -fprofile-use
> -fno-common -o eval.s -freorder-blocks-and-partition
> GNU C (GCC) version 4.8.0 20121126 (experimental) (arm-none-linux-gnueabi)
> compiled by GNU C version 4.4.3, GMP version 4.3.2, MPFR version
> 2.4.2-p1, MPC version 0.8.1
> GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
> GNU C (GCC) version 4.8.0 20121126 (experimental) (arm-none-linux-gnueabi)
> compiled by GNU C version 4.4.3, GMP version 4.3.2, MPFR version
> 2.4.2-p1, MPC version 0.8.1
> GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
> Compiler executable checksum: 45b468efa7c981f9afb44c4dac2424f3
>
>
> Thanks,
> Teresa
>
> On Mon, Nov 26, 2012 at 8:25 AM, Christophe Lyon
> <christophe.l...@linaro.org> wrote:
> > Hi,
> >
> > I have tested your patch on Spec2000 on ARM, and I can still see
> > several failures caused by:
> > "error: fallthru edge crosses section boundary", including the case
> > described in PR55121.
> >
> > On 26 November 2012 16:55, Teresa Johnson <tejohn...@google.com> wrote:
> >> Ping.
> >> Teresa
> >>
> >> On Thu, Nov 15, 2012 at 12:10 PM, Teresa Johnson <tejohn...@google.com>
> >> wrote:
> >>> Revised patch that fixes failures encountered when enabling
> >>> -freorder-blocks-and-partition, including the failure reported in PR
> >>> 53743.
> >>>
> >>> This includes new verification code to ensure no cold blocks dominate hot
> >>> blocks contributed by Steven Bosscher.
> >>>
> >>> I attempted to make the handling of partition updates through the
> >>> optimization
> >>> passes much more consistent, removing a number of partial fixes in the
> >>> code
> >>> stream in the process. The code to fixup partitions (including the
> >>> BB_PARTITION
> >>> assignement, region crossing jump notes, and switch text section notes) is
> >>> now handled in a few centralized locations. For example, inside
> >>> rtl_redirect_edge_and_branch and force_nonfallthru_and_redirect, so that
> >>> callers
> >>> don't need to attempt the fixup themselves.
> >>>
> >>> For optimization passes that make adjustments to the cfg while in cfg
> >>> layout
> >>> mode that are not easy to fix up incrementally, the new routine
> >>> fixup_partitions handles the cleanup globally. This does require
> >>> calculation
> >>> of the dominance relation, however, as far as I can tell the routines
> >>> which
> >>> now invoke this global fixup (try_optimize_cfg and commit_edge_insertions)
> >>> are invoked typically once (or a small number of times in the case of
> >>> try_optimize_cfg) per optimization pass. Additionally, I compared the
> >>> -ftime-report output for some large fdo compilations and saw only minimal
> >>> increases in the dominance computation times, which were only a tiny
> >>> percent
> >>> of the overall compile time.
> >>>
> >>> Additionally, I added a flag to the rtl_data structure to indicate whether
> >>> any partitioning was actually performed, so that optimizations which were
> >>> conservatively disabled whenever the flag_reorder_blocks_and_partition
> >>> is enabled (e.g. try_crossjump_to_edge, part of connect_traces) can be
> >>> less
> >>> conservative for functions where no partitions were formed (e.g. they are
> >>> completely hot).
> >>>
> >>> Bootstrapped and tested on x86_64-unknown-linux-gnu. Also tested with
> >>> SPEC2006 int
> >>> benchmarks and internal google benchmarks using profile feedback and
> >>> -freorder-blocks-and-partition to get more coverage. Ok for trunk?
> >>>
> >>> Thanks,
> >>> Teresa
> >>>
> >>> 2012-11-14 Teresa Johnson <tejohn...@google.com>
> >>> Steven Bosscher <ste...@gcc.gnu.org>
> >>>
> >>> * cfghooks.h (cfg_layout_finalize): New parameter.
> >>> * modulo-sched.c (rest_of_handle_sms): New cfg_layout_finalize
> >>> parameter.
> >>> * ifcvt.c (find_if_case_1): Replace BB_COPY_PARTITION with assert
> >>> as this is now done by redirect_edge_and_branch_force.
> >>> * function.c (thread_prologue_and_epilogue_insns): Insert new bb
> >>> after
> >>> barriers, new cfg_layout_finalize parameter, and don't store exit
> >>> predecessor BB until after it is potentially split.
> >>> * function.h (struct rtl_data): New flag has_bb_partition.
> >>> * hw-doloop.c (reorder_loops): New cfg_layout_finalize parameter.
> >>> * cfgcleanup.c (try_crossjump_to_edge): Only skip optimization if
> >>> any blocks in function actually partitioned.
> >>> (try_optimize_cfg): If cfg changed, invoke fixup_partitions to
> >>> clean
> >>> up partitioning.
> >>> * bb-reorder.c (connect_traces): Only look for partitions and skip
> >>> block copying if any blocks in function actually partitioned.
> >>> (emit_barrier_after_bb): Handle insertion in non-cfglayout mode.
> >>> (find_rarely_executed_basic_blocks_and_crossing_edges): Ensure
> >>> that no cold blocks dominate a hot block.
> >>> (fix_up_fall_thru_edges): Replace BB_COPY_PARTITION with assert
> >>> as this is now done by force_nonfallthru_and_redirect.
> >>> (add_reg_crossing_jump_notes): Handle the fact that some jumps may
> >>> already be marked with region crossing note.
> >>> (reorder_basic_blocks): Only need to verify partitions if any
> >>> blocks in function actually partitioned.
> >>> (insert_section_boundary_note): Only need to insert note if any
> >>> blocks in function actually partitioned.
> >>> (rest_of_handle_reorder_blocks): New cfg_layout_finalize
> >>> parameter, and remove call to insert_section_boundary_note as this
> >>> is now called via cfg_layout_finalize/fixup_reorder_chain.
> >>> (duplicate_computed_gotos): New cfg_layout_finalize
> >>> parameter.
> >>> (partition_hot_cold_basic_blocks): Set flag indicating function
> >>> has bb partitions.
> >>> * bb-reorder.h: Declare insert_section_boundary_note and
> >>> emit_barrier_after_bb, which are no longer static.
> >>> * basic-block.h: Declare new function fixup_partitions.
> >>> * cfgrtl.c (try_redirect_by_replacing_jump): Remove unnecessary
> >>> check for region crossing note.
> >>> (fixup_partition_crossing): New function.
> >>> (fixup_bb_partition): Ditto.
> >>> (rtl_redirect_edge_and_branch): Fixup partition boundaries.
> >>> (force_nonfallthru_and_redirect): Fixup partition boundaries,
> >>> remove old code that tried to do this. Emit barrier correctly
> >>> when we are in cfglayout mode.
> >>> (rtl_split_edge): Correctly fixup partition boundaries.
> >>> (commit_one_edge_insertion): Remove old code that tried to
> >>> fixup region crossing edge since this is now handled in
> >>> split_block, and set up insertion point correctly since
> >>> block may now end in a jump.
> >>> (commit_edge_insertions): Invoke fixup_partitions to sanitize
> >>> partition
> >>> boundaries after optimizations that modify cfg and before trying
> >>> to
> >>> verify the flow info.
> >>> (fixup_partitions): New function.
> >>> (rtl_verify_flow_info_1): Add verification that no cold bbs
> >>> dominate
> >>> hot bbs.
> >>> (record_effective_endpoints): Remove region-crossing notes and
> >>> set flag
> >>> indicating that they need to be reinserted on exit from cfglayout
> >>> mode.
> >>> (outof_cfg_layout_mode): New cfg_layout_finalize parameter.
> >>> (fixup_reorder_chain): Call insert_section_boundary_note if
> >>> necessary.
> >>> Remove old code that attempted to fixup region crossing note as
> >>> this is now handled in force_nonfallthru_and_redirect.
> >>> (duplicate_insn_chain): Don't duplicate switch section notes.
> >>> (cfg_layout_finalize): Pass new parameter to fixup_reorder_chain.
> >>> (rtl_can_remove_branch_p): Remove unnecessary check for region
> >>> crossing
> >>> note.
> >>>
> >>> Index: cfghooks.h
> >>> ===================================================================
> >>> --- cfghooks.h (revision 193376)
> >>> +++ cfghooks.h (working copy)
> >>> @@ -204,7 +204,7 @@ extern void copy_bbs (basic_block *, unsigned, bas
> >>> void account_profile_record (struct profile_record *, int);
> >>>
> >>> extern void cfg_layout_initialize (unsigned int);
> >>> -extern void cfg_layout_finalize (void);
> >>> +extern void cfg_layout_finalize (bool);
> >>>
> >>> /* Hooks containers. */
> >>> extern struct cfg_hooks gimple_cfg_hooks;
> >>> @@ -218,4 +218,3 @@ extern void cfg_layout_rtl_register_cfg_hooks (voi
> >>> extern void gimple_register_cfg_hooks (void);
> >>> extern struct cfg_hooks get_cfg_hooks (void);
> >>> extern void set_cfg_hooks (struct cfg_hooks);
> >>> -
> >>> Index: modulo-sched.c
> >>> ===================================================================
> >>> --- modulo-sched.c (revision 193376)
> >>> +++ modulo-sched.c (working copy)
> >>> @@ -3354,7 +3354,7 @@ rest_of_handle_sms (void)
> >>> if (bb->next_bb != EXIT_BLOCK_PTR)
> >>> bb->aux = bb->next_bb;
> >>> free_dominance_info (CDI_DOMINATORS);
> >>> - cfg_layout_finalize ();
> >>> + cfg_layout_finalize (false);
> >>> #endif /* INSN_SCHEDULING */
> >>> return 0;
> >>> }
> >>> Index: ifcvt.c
> >>> ===================================================================
> >>> --- ifcvt.c (revision 193376)
> >>> +++ ifcvt.c (working copy)
> >>> @@ -3900,10 +3900,9 @@ find_if_case_1 (basic_block test_bb, edge then_edg
> >>> if (new_bb)
> >>> {
> >>> df_bb_replace (then_bb_index, new_bb);
> >>> - /* Since the fallthru edge was redirected from test_bb to new_bb,
> >>> - we need to ensure that new_bb is in the same partition as
> >>> - test bb (you can not fall through across section boundaries).
> >>> */
> >>> - BB_COPY_PARTITION (new_bb, test_bb);
> >>> + /* This should have been done above via
> >>> force_nonfallthru_and_redirect
> >>> + (possibly called from redirect_edge_and_branch_force). */
> >>> + gcc_assert (BB_PARTITION (new_bb) == BB_PARTITION (test_bb));
> >>> }
> >>>
> >>> num_true_changes++;
> >>> Index: function.c
> >>> ===================================================================
> >>> --- function.c (revision 193376)
> >>> +++ function.c (working copy)
> >>> @@ -6249,8 +6249,10 @@ thread_prologue_and_epilogue_insns (void)
> >>> break;
> >>> if (e)
> >>> {
> >>> - copy_bb = create_basic_block (NEXT_INSN (BB_END
> >>> (e->src)),
> >>> - NULL_RTX, e->src);
> >>> + /* Make sure we insert after any barriers. */
> >>> + rtx end = get_last_bb_insn (e->src);
> >>> + copy_bb = create_basic_block (NEXT_INSN (end),
> >>> + NULL_RTX, e->src);
> >>> BB_COPY_PARTITION (copy_bb, e->src);
> >>> }
> >>> else
> >>> @@ -6475,7 +6477,7 @@ thread_prologue_and_epilogue_insns (void)
> >>> if (cur_bb->index >= NUM_FIXED_BLOCKS
> >>> && cur_bb->next_bb->index >= NUM_FIXED_BLOCKS)
> >>> cur_bb->aux = cur_bb->next_bb;
> >>> - cfg_layout_finalize ();
> >>> + cfg_layout_finalize (false);
> >>> }
> >>>
> >>> epilogue_done:
> >>> @@ -6517,7 +6519,7 @@ epilogue_done:
> >>> basic_block simple_return_block_cold = NULL;
> >>> edge pending_edge_hot = NULL;
> >>> edge pending_edge_cold = NULL;
> >>> - basic_block exit_pred = EXIT_BLOCK_PTR->prev_bb;
> >>> + basic_block exit_pred;
> >>> int i;
> >>>
> >>> gcc_assert (entry_edge != orig_entry_edge);
> >>> @@ -6545,6 +6547,12 @@ epilogue_done:
> >>> else
> >>> pending_edge_cold = e;
> >>> }
> >>> +
> >>> + /* Save a pointer to the exit's predecessor BB for use in
> >>> + inserting new BBs at the end of the function. Do this
> >>> + after the call to split_block above which may split
> >>> + the original exit pred. */
> >>> + exit_pred = EXIT_BLOCK_PTR->prev_bb;
> >>>
> >>> FOR_EACH_VEC_ELT (edge, unconverted_simple_returns, i, e)
> >>> {
> >>> Index: function.h
> >>> ===================================================================
> >>> --- function.h (revision 193376)
> >>> +++ function.h (working copy)
> >>> @@ -459,6 +459,11 @@ struct GTY(()) rtl_data {
> >>> sched2) and is useful only if the port defines LEAF_REGISTERS. */
> >>> bool uses_only_leaf_regs;
> >>>
> >>> + /* Nonzero if the function being compiled has undergone hot/cold
> >>> partitioning
> >>> + (under flag_reorder_blocks_and_partition) and has at least one cold
> >>> + block. */
> >>> + bool has_bb_partition;
> >>> +
> >>> /* Like regs_ever_live, but 1 if a reg is set or clobbered from an
> >>> asm. Unlike regs_ever_live, elements of this array corresponding
> >>> to eliminable regs (like the frame pointer) are set if an asm
> >>> Index: hw-doloop.c
> >>> ===================================================================
> >>> --- hw-doloop.c (revision 193376)
> >>> +++ hw-doloop.c (working copy)
> >>> @@ -547,7 +547,7 @@ reorder_loops (hwloop_info loops)
> >>> else
> >>> bb->aux = NULL;
> >>> }
> >>> - cfg_layout_finalize ();
> >>> + cfg_layout_finalize (false);
> >>> clear_aux_for_blocks ();
> >>> df_analyze ();
> >>> }
> >>> Index: cfgcleanup.c
> >>> ===================================================================
> >>> --- cfgcleanup.c (revision 193376)
> >>> +++ cfgcleanup.c (working copy)
> >>> @@ -1824,7 +1824,7 @@ try_crossjump_to_edge (int mode, edge e1, edge e2,
> >>> partition boundaries). See the comments at the top of
> >>> bb-reorder.c:partition_hot_cold_basic_blocks for complete details.
> >>> */
> >>>
> >>> - if (flag_reorder_blocks_and_partition && reload_completed)
> >>> + if (crtl->has_bb_partition && reload_completed)
> >>> return false;
> >>>
> >>> /* Search backward through forwarder blocks. We don't need to worry
> >>> @@ -2767,10 +2767,21 @@ try_optimize_cfg (int mode)
> >>> df_analyze ();
> >>> }
> >>>
> >>> + if (changed)
> >>> + {
> >>> + /* Edge forwarding in particular can cause hot blocks
> >>> previously
> >>> + reached by both hot and cold blocks to become dominated
> >>> only
> >>> + by cold blocks. This will cause the verification below
> >>> to fail,
> >>> + and lead to now cold code in the hot section. This is
> >>> not easy
> >>> + to detect and fix during edge forwarding, and in some
> >>> cases
> >>> + is only visible after newly unreachable blocks are
> >>> deleted,
> >>> + which will be done in fixup_partitions. */
> >>> + fixup_partitions ();
> >>> +
> >>> #ifdef ENABLE_CHECKING
> >>> - if (changed)
> >>> - verify_flow_info ();
> >>> + verify_flow_info ();
> >>> #endif
> >>> + }
> >>>
> >>> changed_overall |= changed;
> >>> first_pass = false;
> >>> Index: bb-reorder.c
> >>> ===================================================================
> >>> --- bb-reorder.c (revision 193376)
> >>> +++ bb-reorder.c (working copy)
> >>> @@ -1054,7 +1054,7 @@ connect_traces (int n_traces, struct trace *traces
> >>> current_partition = BB_PARTITION (traces[0].first);
> >>> two_passes = false;
> >>>
> >>> - if (flag_reorder_blocks_and_partition)
> >>> + if (crtl->has_bb_partition)
> >>> for (i = 0; i < n_traces && !two_passes; i++)
> >>> if (BB_PARTITION (traces[0].first)
> >>> != BB_PARTITION (traces[i].first))
> >>> @@ -1263,7 +1263,7 @@ connect_traces (int n_traces, struct trace *traces
> >>> }
> >>> }
> >>>
> >>> - if (flag_reorder_blocks_and_partition)
> >>> + if (crtl->has_bb_partition)
> >>> try_copy = false;
> >>>
> >>> /* Copy tiny blocks always; copy larger blocks only when the
> >>> @@ -1381,13 +1381,14 @@ get_uncond_jump_length (void)
> >>> return length;
> >>> }
> >>>
> >>> -/* Emit a barrier into the footer of BB. */
> >>> +/* Emit a barrier after BB, into the footer if we are in CFGLAYOUT mode.
> >>> */
> >>>
> >>> -static void
> >>> +void
> >>> emit_barrier_after_bb (basic_block bb)
> >>> {
> >>> rtx barrier = emit_barrier_after (BB_END (bb));
> >>> - BB_FOOTER (bb) = unlink_insn_chain (barrier, barrier);
> >>> + if (current_ir_type () == IR_RTL_CFGLAYOUT)
> >>> + BB_FOOTER (bb) = unlink_insn_chain (barrier, barrier);
> >>> }
> >>>
> >>> /* The landing pad OLD_LP, in block OLD_BB, has edges from both
> >>> partitions.
> >>> @@ -1463,18 +1464,109 @@
> >>> find_rarely_executed_basic_blocks_and_crossing_edg
> >>> {
> >>> VEC(edge, heap) *crossing_edges = NULL;
> >>> basic_block bb;
> >>> - edge e;
> >>> - edge_iterator ei;
> >>> + edge e, e2;
> >>> + edge_iterator ei, ei2;
> >>> + unsigned int cold_bb_count = 0;
> >>> + VEC (basic_block, heap) *bbs_in_hot_partition = NULL;
> >>> + VEC (basic_block, heap) *bbs_newly_hot = NULL;
> >>>
> >>> /* Mark which partition (hot/cold) each basic block belongs in. */
> >>> FOR_EACH_BB (bb)
> >>> {
> >>> if (probably_never_executed_bb_p (cfun, bb))
> >>> - BB_SET_PARTITION (bb, BB_COLD_PARTITION);
> >>> + {
> >>> + BB_SET_PARTITION (bb, BB_COLD_PARTITION);
> >>> + cold_bb_count++;
> >>> + }
> >>> else
> >>> - BB_SET_PARTITION (bb, BB_HOT_PARTITION);
> >>> + {
> >>> + BB_SET_PARTITION (bb, BB_HOT_PARTITION);
> >>> + VEC_safe_push (basic_block, heap, bbs_in_hot_partition, bb);
> >>> + }
> >>> }
> >>>
> >>> + /* Ensure that no cold bbs dominate hot bbs. This could happen as a
> >>> result of
> >>> + several different possibilities. One is that there are edge weight
> >>> insanities
> >>> + due to optimization phases that do not properly update basic block
> >>> profile
> >>> + counts. The second is that the entry of the function may not be
> >>> hot, because
> >>> + it is entered fewer times than the number of profile training runs,
> >>> but there
> >>> + is a loop inside the function that causes blocks within the
> >>> function to be
> >>> + above the threshold for hotness. */
> >>> + if (cold_bb_count)
> >>> + {
> >>> + bool dom_calculated_here = !dom_info_available_p (CDI_DOMINATORS);
> >>> +
> >>> + if (dom_calculated_here)
> >>> + calculate_dominance_info (CDI_DOMINATORS);
> >>> +
> >>> + /* Keep examining hot bbs until we have either checked them all, or
> >>> + re-marked all cold bbs hot. */
> >>> + while (! VEC_empty (basic_block, bbs_in_hot_partition)
> >>> + && cold_bb_count)
> >>> + {
> >>> + basic_block dom_bb;
> >>> +
> >>> + bb = VEC_pop (basic_block, bbs_in_hot_partition);
> >>> + dom_bb = get_immediate_dominator (CDI_DOMINATORS, bb);
> >>> +
> >>> + /* If bb's immediate dominator is also hot then it is ok. */
> >>> + if (BB_PARTITION (dom_bb) != BB_COLD_PARTITION)
> >>> + continue;
> >>> +
> >>> + /* We have a hot bb with an immediate dominator that is cold.
> >>> + The dominator needs to be re-marked to hot. */
> >>> + BB_SET_PARTITION (dom_bb, BB_HOT_PARTITION);
> >>> + cold_bb_count--;
> >>> +
> >>> + /* Now we need to examine newly-hot dom_bb to see if it is also
> >>> + dominated by a cold bb. */
> >>> + VEC_safe_push (basic_block, heap, bbs_in_hot_partition,
> >>> dom_bb);
> >>> +
> >>> + /* We should also adjust any cold blocks that the newly-hot bb
> >>> + feeds and see if it makes sense to re-mark those as hot as
> >>> + well. */
> >>> + VEC_safe_push (basic_block, heap, bbs_newly_hot, dom_bb);
> >>> + while (! VEC_empty (basic_block, bbs_newly_hot))
> >>> + {
> >>> + basic_block new_hot_bb = VEC_pop (basic_block,
> >>> bbs_newly_hot);
> >>> + /* Examine all successors of this newly-hot bb to see if
> >>> they
> >>> + are cold and should be re-marked as hot. */
> >>> + FOR_EACH_EDGE (e, ei, new_hot_bb->succs)
> >>> + {
> >>> + bool any_cold_preds = false;
> >>> + basic_block succ = e->dest;
> >>> + if (BB_PARTITION (succ) != BB_COLD_PARTITION)
> >>> + continue;
> >>> + /* Does this block have any cold predecessors now? */
> >>> + FOR_EACH_EDGE (e2, ei2, succ->preds)
> >>> + {
> >>> + if (BB_PARTITION (e2->src) == BB_COLD_PARTITION)
> >>> + {
> >>> + any_cold_preds = true;
> >>> + break;
> >>> + }
> >>> + }
> >>> + if (any_cold_preds)
> >>> + continue;
> >>> +
> >>> + /* Here we have a successor of newly-hot bb that is
> >>> cold
> >>> + but no longer has any cold precessessors. Since the
> >>> original
> >>> + assignment of our newly-hot bb was incorrect, this
> >>> successor's
> >>> + assignment as cold is also suspect. Go ahead and
> >>> re-mark it
> >>> + as hot now too. Better heuristics may be in order
> >>> here. */
> >>> + BB_SET_PARTITION (succ, BB_HOT_PARTITION);
> >>> + cold_bb_count--;
> >>> + VEC_safe_push (basic_block, heap,
> >>> bbs_in_hot_partition, succ);
> >>> + /* Examine this successor as a newly-hot bb. */
> >>> + VEC_safe_push (basic_block, heap, bbs_newly_hot, succ);
> >>> + }
> >>> + }
> >>> + }
> >>> +
> >>> + if (dom_calculated_here)
> >>> + free_dominance_info (CDI_DOMINATORS);
> >>> + }
> >>> +
> >>> /* The format of .gcc_except_table does not allow landing pads to
> >>> be in a different partition as the throw. Fix this by either
> >>> moving or duplicating the landing pads. */
> >>> @@ -1766,10 +1858,10 @@ fix_up_fall_thru_edges (void)
> >>> new_bb->aux = cur_bb->aux;
> >>> cur_bb->aux = new_bb;
> >>>
> >>> - /* Make sure new fall-through bb is in same
> >>> - partition as bb it's falling through from. */
> >>> + /* This is done by force_nonfallthru_and_redirect.
> >>> */
> >>> + gcc_assert (BB_PARTITION (new_bb)
> >>> + == BB_PARTITION (cur_bb));
> >>>
> >>> - BB_COPY_PARTITION (new_bb, cur_bb);
> >>> single_succ_edge (new_bb)->flags |= EDGE_CROSSING;
> >>> }
> >>> else
> >>> @@ -2067,7 +2159,10 @@ add_reg_crossing_jump_notes (void)
> >>> FOR_EACH_BB (bb)
> >>> FOR_EACH_EDGE (e, ei, bb->succs)
> >>> if ((e->flags & EDGE_CROSSING)
> >>> - && JUMP_P (BB_END (e->src)))
> >>> + && JUMP_P (BB_END (e->src))
> >>> + /* Some notes were added during fix_up_fall_thru_edges, via
> >>> + force_nonfallthru_and_redirect. */
> >>> + && !find_reg_note (BB_END (e->src), REG_CROSSING_JUMP,
> >>> NULL_RTX))
> >>> add_reg_note (BB_END (e->src), REG_CROSSING_JUMP, NULL_RTX);
> >>> }
> >>>
> >>> @@ -2160,7 +2255,7 @@ reorder_basic_blocks (void)
> >>> dump_flow_info (dump_file, dump_flags);
> >>> }
> >>>
> >>> - if (flag_reorder_blocks_and_partition)
> >>> + if (crtl->has_bb_partition)
> >>> verify_hot_cold_block_grouping ();
> >>> }
> >>>
> >>> @@ -2172,14 +2267,14 @@ reorder_basic_blocks (void)
> >>> encountering this note will make the compiler switch between the
> >>> hot and cold text sections. */
> >>>
> >>> -static void
> >>> +void
> >>> insert_section_boundary_note (void)
> >>> {
> >>> basic_block bb;
> >>> rtx new_note;
> >>> int first_partition = 0;
> >>>
> >>> - if (!flag_reorder_blocks_and_partition)
> >>> + if (!crtl->has_bb_partition)
> >>> return;
> >>>
> >>> FOR_EACH_BB (bb)
> >>> @@ -2222,10 +2317,8 @@ rest_of_handle_reorder_blocks (void)
> >>> FOR_EACH_BB (bb)
> >>> if (bb->next_bb != EXIT_BLOCK_PTR)
> >>> bb->aux = bb->next_bb;
> >>> - cfg_layout_finalize ();
> >>> + cfg_layout_finalize (true);
> >>>
> >>> - /* Add NOTE_INSN_SWITCH_TEXT_SECTIONS notes. */
> >>> - insert_section_boundary_note ();
> >>> return 0;
> >>> }
> >>>
> >>> @@ -2366,7 +2459,7 @@ duplicate_computed_gotos (void)
> >>> }
> >>>
> >>> done:
> >>> - cfg_layout_finalize ();
> >>> + cfg_layout_finalize (false);
> >>>
> >>> BITMAP_FREE (candidates);
> >>> return 0;
> >>> @@ -2511,6 +2604,8 @@ partition_hot_cold_basic_blocks (void)
> >>> if (crossing_edges == NULL)
> >>> return 0;
> >>>
> >>> + crtl->has_bb_partition = true;
> >>> +
> >>> /* Make sure the source of any crossing edge ends in a jump and the
> >>> destination of any crossing edge has a label. */
> >>> add_labels_and_missing_jumps (crossing_edges);
> >>> Index: bb-reorder.h
> >>> ===================================================================
> >>> --- bb-reorder.h (revision 193376)
> >>> +++ bb-reorder.h (working copy)
> >>> @@ -36,4 +36,8 @@ extern struct target_bb_reorder *this_target_bb_re
> >>>
> >>> extern int get_uncond_jump_length (void);
> >>>
> >>> +extern void insert_section_boundary_note (void);
> >>> +
> >>> +extern void emit_barrier_after_bb (basic_block bb);
> >>> +
> >>> #endif
> >>> Index: basic-block.h
> >>> ===================================================================
> >>> --- basic-block.h (revision 193376)
> >>> +++ basic-block.h (working copy)
> >>> @@ -806,6 +806,7 @@ extern basic_block force_nonfallthru_and_redirect
> >>> extern bool contains_no_active_insn_p (const_basic_block);
> >>> extern bool forwarder_block_p (const_basic_block);
> >>> extern bool can_fallthru (basic_block, basic_block);
> >>> +extern void fixup_partitions (void);
> >>>
> >>> /* In cfgbuild.c. */
> >>> extern void find_many_sub_basic_blocks (sbitmap);
> >>> Index: cfgrtl.c
> >>> ===================================================================
> >>> --- cfgrtl.c (revision 193376)
> >>> +++ cfgrtl.c (working copy)
> >>> @@ -46,6 +46,7 @@ along with GCC; see the file COPYING3. If not see
> >>> #include "tree.h"
> >>> #include "hard-reg-set.h"
> >>> #include "basic-block.h"
> >>> +#include "bb-reorder.h"
> >>> #include "regs.h"
> >>> #include "flags.h"
> >>> #include "function.h"
> >>> @@ -67,11 +68,12 @@ along with GCC; see the file COPYING3. If not see
> >>> Only applicable if the CFG is in cfglayout mode. */
> >>> static GTY(()) rtx cfg_layout_function_footer;
> >>> static GTY(()) rtx cfg_layout_function_header;
> >>> +static bool had_sec_boundary_notes;
> >>>
> >>> static rtx skip_insns_after_block (basic_block);
> >>> static void record_effective_endpoints (void);
> >>> static rtx label_for_bb (basic_block);
> >>> -static void fixup_reorder_chain (void);
> >>> +static void fixup_reorder_chain (bool finalize_reorder_blocks);
> >>>
> >>> void verify_insn_chain (void);
> >>> static void fixup_fallthru_exit_predecessor (void);
> >>> @@ -976,8 +978,7 @@ try_redirect_by_replacing_jump (edge e, basic_bloc
> >>> partition boundaries). See the comments at the top of
> >>> bb-reorder.c:partition_hot_cold_basic_blocks for complete details.
> >>> */
> >>>
> >>> - if (find_reg_note (insn, REG_CROSSING_JUMP, NULL_RTX)
> >>> - || BB_PARTITION (src) != BB_PARTITION (target))
> >>> + if (BB_PARTITION (src) != BB_PARTITION (target))
> >>> return NULL;
> >>>
> >>> /* We can replace or remove a complex jump only when we have exactly
> >>> @@ -1286,6 +1287,71 @@ redirect_branch_edge (edge e, basic_block target)
> >>> return e;
> >>> }
> >>>
> >>> +/* Called when edge E has been redirected to a new destination,
> >>> + in order to update the region crossing flag on the edge and
> >>> + jump. */
> >>> +
> >>> +static void
> >>> +fixup_partition_crossing (edge e, basic_block target)
> >>> +{
> >>> + rtx note;
> >>> +
> >>> + gcc_assert (e->dest == target);
> >>> +
> >>> + if (e->src == ENTRY_BLOCK_PTR || target == EXIT_BLOCK_PTR)
> >>> + return;
> >>> + /* If we redirected an existing edge, it may already be marked
> >>> + crossing, even though the new src is missing a reg crossing note.
> >>> + But make sure reg crossing note doesn't already exist before
> >>> + inserting. */
> >>> + if (BB_PARTITION (e->src) != BB_PARTITION (target))
> >>> + {
> >>> + e->flags |= EDGE_CROSSING;
> >>> + note = find_reg_note (BB_END (e->src), REG_CROSSING_JUMP,
> >>> NULL_RTX);
> >>> + if (JUMP_P (BB_END (e->src))
> >>> + && !note)
> >>> + add_reg_note (BB_END (e->src), REG_CROSSING_JUMP, NULL_RTX);
> >>> + }
> >>> + else if (BB_PARTITION (e->src) == BB_PARTITION (target))
> >>> + {
> >>> + e->flags &= ~EDGE_CROSSING;
> >>> + /* Remove the region crossing note from jump at end of
> >>> + e->src if it exists. */
> >>> + note = find_reg_note (BB_END (e->src), REG_CROSSING_JUMP,
> >>> NULL_RTX);
> >>> + if (note)
> >>> + remove_note (BB_END (e->src), note);
> >>> + }
> >>> +}
> >>> +
> >>> +/* Called when block BB has been reassigned to a different partition,
> >>> + to ensure that the region crossing attributes are updated. */
> >>> +
> >>> +static void
> >>> +fixup_bb_partition (basic_block bb)
> >>> +{
> >>> + edge e;
> >>> + edge_iterator ei;
> >>> +
> >>> + /* Now need to make bb's pred edges non-region crossing. */
> >>> + FOR_EACH_EDGE (e, ei, bb->preds)
> >>> + {
> >>> + fixup_partition_crossing (e, e->dest);
> >>> + }
> >>> +
> >>> + /* Possibly need to make bb's successor edges region crossing,
> >>> + or remove stale region crossing. */
> >>> + FOR_EACH_EDGE (e, ei, bb->succs)
> >>> + {
> >>> + if ((e->flags & EDGE_FALLTHRU)
> >>> + && BB_PARTITION (bb) != BB_PARTITION (e->dest)
> >>> + && e->dest != EXIT_BLOCK_PTR)
> >>> + /* force_nonfallthru_and_redirect calls
> >>> fixup_partition_crossing. */
> >>> + force_nonfallthru (e);
> >>> + else
> >>> + fixup_partition_crossing (e, e->dest);
> >>> + }
> >>> +}
> >>> +
> >>> /* Attempt to change code to redirect edge E to TARGET. Don't do that on
> >>> expense of adding new instructions or reordering basic blocks.
> >>>
> >>> @@ -1302,16 +1368,18 @@ rtl_redirect_edge_and_branch (edge e, basic_block
> >>> {
> >>> edge ret;
> >>> basic_block src = e->src;
> >>> + basic_block dest = e->dest;
> >>>
> >>> if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH))
> >>> return NULL;
> >>>
> >>> - if (e->dest == target)
> >>> + if (dest == target)
> >>> return e;
> >>>
> >>> if ((ret = try_redirect_by_replacing_jump (e, target, false)) != NULL)
> >>> {
> >>> df_set_bb_dirty (src);
> >>> + fixup_partition_crossing (ret, target);
> >>> return ret;
> >>> }
> >>>
> >>> @@ -1320,6 +1388,7 @@ rtl_redirect_edge_and_branch (edge e, basic_block
> >>> return NULL;
> >>>
> >>> df_set_bb_dirty (src);
> >>> + fixup_partition_crossing (ret, target);
> >>> return ret;
> >>> }
> >>>
> >>> @@ -1454,18 +1523,16 @@ force_nonfallthru_and_redirect (edge e, basic_bloc
> >>> /* Make sure new block ends up in correct hot/cold section. */
> >>>
> >>> BB_COPY_PARTITION (jump_block, e->src);
> >>> - if (flag_reorder_blocks_and_partition
> >>> - && targetm_common.have_named_sections
> >>> - && JUMP_P (BB_END (jump_block))
> >>> - && !any_condjump_p (BB_END (jump_block))
> >>> - && (EDGE_SUCC (jump_block, 0)->flags & EDGE_CROSSING))
> >>> - add_reg_note (BB_END (jump_block), REG_CROSSING_JUMP, NULL_RTX);
> >>>
> >>> /* Wire edge in. */
> >>> new_edge = make_edge (e->src, jump_block, EDGE_FALLTHRU);
> >>> new_edge->probability = probability;
> >>> new_edge->count = count;
> >>>
> >>> + /* If e->src was previously region crossing, it no longer is
> >>> + and the reg crossing note should be removed. */
> >>> + fixup_partition_crossing (new_edge, jump_block);
> >>> +
> >>> /* Redirect old edge. */
> >>> redirect_edge_pred (e, jump_block);
> >>> e->probability = REG_BR_PROB_BASE;
> >>> @@ -1521,13 +1588,16 @@ force_nonfallthru_and_redirect (edge e, basic_bloc
> >>> LABEL_NUSES (label)++;
> >>> }
> >>>
> >>> - emit_barrier_after (BB_END (jump_block));
> >>> + /* We might be in cfg layout mode, and if so, the following routine
> >>> will
> >>> + insert the barrier correctly. */
> >>> + emit_barrier_after_bb (jump_block);
> >>> redirect_edge_succ_nodup (e, target);
> >>>
> >>> if (abnormal_edge_flags)
> >>> make_edge (src, target, abnormal_edge_flags);
> >>>
> >>> df_mark_solutions_dirty ();
> >>> + fixup_partition_crossing (e, target);
> >>> return new_bb;
> >>> }
> >>>
> >>> @@ -1626,7 +1696,7 @@ rtl_move_block_after (basic_block bb ATTRIBUTE_UNU
> >>> static basic_block
> >>> rtl_split_edge (edge edge_in)
> >>> {
> >>> - basic_block bb;
> >>> + basic_block bb, new_bb;
> >>> rtx before;
> >>>
> >>> /* Abnormal edges cannot be split. */
> >>> @@ -1659,12 +1729,26 @@ rtl_split_edge (edge edge_in)
> >>> else
> >>> {
> >>> bb = create_basic_block (before, NULL, edge_in->dest->prev_bb);
> >>> - /* ??? Why not edge_in->dest->prev_bb here? */
> >>> - BB_COPY_PARTITION (bb, edge_in->dest);
> >>> + if (edge_in->src == ENTRY_BLOCK_PTR)
> >>> + BB_COPY_PARTITION (bb, edge_in->dest);
> >>> + else
> >>> + /* Put the split bb into the src partition, to avoid creating
> >>> + a situation where a cold bb dominates a hot bb, in the case
> >>> + where src is cold and dest is hot. The src will dominate
> >>> + the new bb (whereas it might not have dominated dest). */
> >>> + BB_COPY_PARTITION (bb, edge_in->src);
> >>> }
> >>>
> >>> make_single_succ_edge (bb, edge_in->dest, EDGE_FALLTHRU);
> >>>
> >>> + /* Can't allow a region crossing edge to be fallthrough. */
> >>> + if (BB_PARTITION (bb) != BB_PARTITION (edge_in->dest)
> >>> + && edge_in->dest != EXIT_BLOCK_PTR)
> >>> + {
> >>> + new_bb = force_nonfallthru (single_succ_edge (bb));
> >>> + gcc_assert (!new_bb);
> >>> + }
> >>> +
> >>> /* For non-fallthru edges, we must adjust the predecessor's
> >>> jump instruction to target our new block. */
> >>> if ((edge_in->flags & EDGE_FALLTHRU) == 0)
> >>> @@ -1777,17 +1861,13 @@ commit_one_edge_insertion (edge e)
> >>> else
> >>> {
> >>> bb = split_edge (e);
> >>> - after = BB_END (bb);
> >>>
> >>> - if (flag_reorder_blocks_and_partition
> >>> - && targetm_common.have_named_sections
> >>> - && e->src != ENTRY_BLOCK_PTR
> >>> - && BB_PARTITION (e->src) == BB_COLD_PARTITION
> >>> - && !(e->flags & EDGE_CROSSING)
> >>> - && JUMP_P (after)
> >>> - && !any_condjump_p (after)
> >>> - && (single_succ_edge (bb)->flags & EDGE_CROSSING))
> >>> - add_reg_note (after, REG_CROSSING_JUMP, NULL_RTX);
> >>> + /* If e crossed a partition boundary, we needed to make bb end in
> >>> + a region-crossing jump, even though it was originally fallthru.
> >>> */
> >>> + if (JUMP_P (BB_END (bb)))
> >>> + before = BB_END (bb);
> >>> + else
> >>> + after = BB_END (bb);
> >>> }
> >>>
> >>> /* Now that we've found the spot, do the insertion. */
> >>> @@ -1827,6 +1907,14 @@ commit_edge_insertions (void)
> >>> {
> >>> basic_block bb;
> >>>
> >>> + /* Optimization passes that invoke this routine can cause hot blocks
> >>> + previously reached by both hot and cold blocks to become dominated
> >>> only
> >>> + by cold blocks. This will cause the verification below to fail,
> >>> + and lead to now cold code in the hot section. In some cases this
> >>> + may only be visible after newly unreachable blocks are deleted,
> >>> + which will be done by fixup_partitions. */
> >>> + fixup_partitions ();
> >>> +
> >>> #ifdef ENABLE_CHECKING
> >>> verify_flow_info ();
> >>> #endif
> >>> @@ -2028,7 +2116,75 @@ get_last_bb_insn (basic_block bb)
> >>>
> >>> return end;
> >>> }
> >>> -
> >>> +
> >>> +/* Perform cleanup on the hot/cold bb partitioning after optimization
> >>> + passes that modify the cfg. */
> >>> +
> >>> +void
> >>> +fixup_partitions (void)
> >>> +{
> >>> + basic_block bb;
> >>> +
> >>> + if (!crtl->has_bb_partition)
> >>> + return;
> >>> +
> >>> + /* Delete any blocks that became unreachable and weren't
> >>> + already cleaned up, for example during edge forwarding
> >>> + and convert_jumps_to_returns. This will expose more
> >>> + opportunities for fixing the partition boundaries here.
> >>> + Also, the calculation of the dominance graph during verification
> >>> + will assert if there are unreachable nodes. */
> >>> + delete_unreachable_blocks ();
> >>> +
> >>> + /* If there are partitions, do a sanity check on them: A basic block in
> >>> + a cold partition cannot dominate a basic block in a hot partition.
> >>> + Fixup any that now violate this requirement, as a result of edge
> >>> + forwarding and unreachable block deletion. */
> >>> + VEC (basic_block, heap) *bbs_in_cold_partition = NULL;
> >>> + VEC (basic_block, heap) *bbs_to_fix = NULL;
> >>> + FOR_EACH_BB (bb)
> >>> + if ((BB_PARTITION (bb) == BB_COLD_PARTITION))
> >>> + VEC_safe_push (basic_block, heap, bbs_in_cold_partition, bb);
> >>> + if (! VEC_empty (basic_block, bbs_in_cold_partition))
> >>> + {
> >>> + bool dom_calculated_here = !dom_info_available_p (CDI_DOMINATORS);
> >>> + basic_block son;
> >>> +
> >>> + if (dom_calculated_here)
> >>> + calculate_dominance_info (CDI_DOMINATORS);
> >>> +
> >>> + while (! VEC_empty (basic_block, bbs_in_cold_partition))
> >>> + {
> >>> + bb = VEC_pop (basic_block, bbs_in_cold_partition);
> >>> + /* If bb is not yet cold (because it was added below as
> >>> + a block dominated by a cold bb) then mark it cold here. */
> >>> + if ((BB_PARTITION (bb) != BB_COLD_PARTITION))
> >>> + {
> >>> + BB_SET_PARTITION (bb, BB_COLD_PARTITION);
> >>> + VEC_safe_push (basic_block, heap, bbs_to_fix, bb);
> >>> + }
> >>> + /* Any blocks dominated by a block in the cold section
> >>> + must also be cold. */
> >>> + for (son = first_dom_son (CDI_DOMINATORS, bb);
> >>> + son;
> >>> + son = next_dom_son (CDI_DOMINATORS, son))
> >>> + VEC_safe_push (basic_block, heap, bbs_in_cold_partition,
> >>> son);
> >>> + }
> >>> +
> >>> + if (dom_calculated_here)
> >>> + free_dominance_info (CDI_DOMINATORS);
> >>> + }
> >>> +
> >>> + /* Do the partition fixup after all necessary blocks have been
> >>> converted to
> >>> + cold, so that we only update the region crossings the minimum
> >>> number of
> >>> + places, which can require forcing edges to be non fallthru. */
> >>> + while (! VEC_empty (basic_block, bbs_to_fix))
> >>> + {
> >>> + bb = VEC_pop (basic_block, bbs_to_fix);
> >>> + fixup_bb_partition (bb);
> >>> + }
> >>> +}
> >>> +
> >>> /* Verify the CFG and RTL consistency common for both underlying RTL and
> >>> cfglayout RTL.
> >>>
> >>> @@ -2052,6 +2208,7 @@ rtl_verify_flow_info_1 (void)
> >>> rtx x;
> >>> int err = 0;
> >>> basic_block bb;
> >>> + bool have_partitions = false;
> >>>
> >>> /* Check the general integrity of the basic blocks. */
> >>> FOR_EACH_BB_REVERSE (bb)
> >>> @@ -2169,6 +2326,8 @@ rtl_verify_flow_info_1 (void)
> >>>
> >>> if (e->flags & EDGE_ABNORMAL)
> >>> n_abnormal++;
> >>> +
> >>> + have_partitions |= is_crossing;
> >>> }
> >>>
> >>> if (n_eh && !find_reg_note (BB_END (bb), REG_EH_REGION, NULL_RTX))
> >>> @@ -2293,6 +2452,40 @@ rtl_verify_flow_info_1 (void)
> >>> }
> >>> }
> >>>
> >>> + /* If there are partitions, do a sanity check on them: A basic block in
> >>> + a cold partition cannot dominate a basic block in a hot partition.
> >>> */
> >>> + VEC (basic_block, heap) *bbs_in_cold_partition = NULL;
> >>> + if (have_partitions && !err)
> >>> + FOR_EACH_BB (bb)
> >>> + if ((BB_PARTITION (bb) == BB_COLD_PARTITION))
> >>> + VEC_safe_push (basic_block, heap, bbs_in_cold_partition, bb);
> >>> + if (! VEC_empty (basic_block, bbs_in_cold_partition))
> >>> + {
> >>> + bool dom_calculated_here = !dom_info_available_p (CDI_DOMINATORS);
> >>> + basic_block son;
> >>> +
> >>> + if (dom_calculated_here)
> >>> + calculate_dominance_info (CDI_DOMINATORS);
> >>> +
> >>> + while (! VEC_empty (basic_block, bbs_in_cold_partition))
> >>> + {
> >>> + bb = VEC_pop (basic_block, bbs_in_cold_partition);
> >>> + if ((BB_PARTITION (bb) != BB_COLD_PARTITION))
> >>> + {
> >>> + error ("non-cold basic block %d dominated "
> >>> + "by a block in the cold partition", bb->index);
> >>> + err = 1;
> >>> + }
> >>> + for (son = first_dom_son (CDI_DOMINATORS, bb);
> >>> + son;
> >>> + son = next_dom_son (CDI_DOMINATORS, son))
> >>> + VEC_safe_push (basic_block, heap, bbs_in_cold_partition,
> >>> son);
> >>> + }
> >>> +
> >>> + if (dom_calculated_here)
> >>> + free_dominance_info (CDI_DOMINATORS);
> >>> + }
> >>> +
> >>> /* Clean up. */
> >>> return err;
> >>> }
> >>> @@ -2965,14 +3158,41 @@ record_effective_endpoints (void)
> >>> else
> >>> cfg_layout_function_header = NULL_RTX;
> >>>
> >>> + had_sec_boundary_notes = false;
> >>> +
> >>> next_insn = get_insns ();
> >>> FOR_EACH_BB (bb)
> >>> {
> >>> rtx end;
> >>>
> >>> if (PREV_INSN (BB_HEAD (bb)) && next_insn != BB_HEAD (bb))
> >>> - BB_HEADER (bb) = unlink_insn_chain (next_insn,
> >>> - PREV_INSN (BB_HEAD (bb)));
> >>> + {
> >>> + /* Rather than try to keep section boundary notes incrementally
> >>> + up-to-date through cfg layout optimizations, simply remove
> >>> them
> >>> + and flag that they should be re-inserted when exiting
> >>> + cfg layout mode. */
> >>> + rtx check_insn = next_insn;
> >>> + while (check_insn)
> >>> + {
> >>> + if (NOTE_P (check_insn)
> >>> + && NOTE_KIND (check_insn) ==
> >>> NOTE_INSN_SWITCH_TEXT_SECTIONS)
> >>> + {
> >>> + had_sec_boundary_notes |= true;
> >>> + /* Remove note from chain. Grab new next_insn first. */
> >>> + if (next_insn == check_insn)
> >>> + next_insn = NEXT_INSN (check_insn);
> >>> + /* Delete note. */
> >>> + delete_insn (check_insn);
> >>> + /* There will only be one. */
> >>> + break;
> >>> + }
> >>> + check_insn = NEXT_INSN (check_insn);
> >>> + }
> >>> + /* If we still have header instructions left after above loop.
> >>> */
> >>> + if (next_insn != BB_HEAD (bb))
> >>> + BB_HEADER (bb) = unlink_insn_chain (next_insn,
> >>> + PREV_INSN (BB_HEAD
> >>> (bb)));
> >>> + }
> >>> end = skip_insns_after_block (bb);
> >>> if (NEXT_INSN (BB_END (bb)) && BB_END (bb) != end)
> >>> BB_FOOTER (bb) = unlink_insn_chain (NEXT_INSN (BB_END (bb)), end);
> >>> @@ -3000,7 +3220,7 @@ outof_cfg_layout_mode (void)
> >>> if (bb->next_bb != EXIT_BLOCK_PTR)
> >>> bb->aux = bb->next_bb;
> >>>
> >>> - cfg_layout_finalize ();
> >>> + cfg_layout_finalize (false);
> >>>
> >>> return 0;
> >>> }
> >>> @@ -3120,10 +3340,13 @@ relink_block_chain (bool stay_in_cfglayout_mode)
> >>> }
> >>>
> >>>
> >>> -/* Given a reorder chain, rearrange the code to match. */
> >>> +/* Given a reorder chain, rearrange the code to match. If
> >>> + this is called when we will FINALIZE_REORDER_BLOCKS, or when
> >>> + section boundary notes were removed on entry to cfg layout
> >>> + mode, insert section boundary notes here. */
> >>>
> >>> static void
> >>> -fixup_reorder_chain (void)
> >>> +fixup_reorder_chain (bool finalize_reorder_blocks)
> >>> {
> >>> basic_block bb;
> >>> rtx insn = NULL;
> >>> @@ -3150,7 +3373,7 @@ static void
> >>> PREV_INSN (BB_HEADER (bb)) = insn;
> >>> insn = BB_HEADER (bb);
> >>> while (NEXT_INSN (insn))
> >>> - insn = NEXT_INSN (insn);
> >>> + insn = NEXT_INSN (insn);
> >>> }
> >>> if (insn)
> >>> NEXT_INSN (insn) = BB_HEAD (bb);
> >>> @@ -3175,6 +3398,11 @@ static void
> >>> insn = NEXT_INSN (insn);
> >>>
> >>> set_last_insn (insn);
> >>> +
> >>> + /* Add NOTE_INSN_SWITCH_TEXT_SECTIONS notes. */
> >>> + if (had_sec_boundary_notes || finalize_reorder_blocks)
> >>> + insert_section_boundary_note ();
> >>> +
> >>> #ifdef ENABLE_CHECKING
> >>> verify_insn_chain ();
> >>> #endif
> >>> @@ -3187,7 +3415,7 @@ static void
> >>> edge e_fall, e_taken, e;
> >>> rtx bb_end_insn;
> >>> rtx ret_label = NULL_RTX;
> >>> - basic_block nb, src_bb;
> >>> + basic_block nb;
> >>> edge_iterator ei;
> >>>
> >>> if (EDGE_COUNT (bb->succs) == 0)
> >>> @@ -3322,7 +3550,6 @@ static void
> >>> /* We got here if we need to add a new jump insn.
> >>> Note force_nonfallthru can delete E_FALL and thus we have to
> >>> save E_FALL->src prior to the call to force_nonfallthru. */
> >>> - src_bb = e_fall->src;
> >>> nb = force_nonfallthru_and_redirect (e_fall, e_fall->dest,
> >>> ret_label);
> >>> if (nb)
> >>> {
> >>> @@ -3330,17 +3557,6 @@ static void
> >>> bb->aux = nb;
> >>> /* Don't process this new block. */
> >>> bb = nb;
> >>> -
> >>> - /* Make sure new bb is tagged for correct section (same as
> >>> - fall-thru source, since you cannot fall-thru across
> >>> - section boundaries). */
> >>> - BB_COPY_PARTITION (src_bb, single_pred (bb));
> >>> - if (flag_reorder_blocks_and_partition
> >>> - && targetm_common.have_named_sections
> >>> - && JUMP_P (BB_END (bb))
> >>> - && !any_condjump_p (BB_END (bb))
> >>> - && (EDGE_SUCC (bb, 0)->flags & EDGE_CROSSING))
> >>> - add_reg_note (BB_END (bb), REG_CROSSING_JUMP, NULL_RTX);
> >>> }
> >>> }
> >>>
> >>> @@ -3644,10 +3860,11 @@ duplicate_insn_chain (rtx from, rtx to)
> >>> case NOTE_INSN_FUNCTION_BEG:
> >>> /* There is always just single entry to function. */
> >>> case NOTE_INSN_BASIC_BLOCK:
> >>> + /* We should only switch text sections once. */
> >>> + case NOTE_INSN_SWITCH_TEXT_SECTIONS:
> >>> break;
> >>>
> >>> case NOTE_INSN_EPILOGUE_BEG:
> >>> - case NOTE_INSN_SWITCH_TEXT_SECTIONS:
> >>> emit_note_copy (insn);
> >>> break;
> >>>
> >>> @@ -3759,10 +3976,13 @@ break_superblocks (void)
> >>> }
> >>>
> >>> /* Finalize the changes: reorder insn list according to the sequence
> >>> specified
> >>> - by aux pointers, enter compensation code, rebuild scope forest. */
> >>> + by aux pointers, enter compensation code, rebuild scope forest. If
> >>> + this is called when we will FINALIZE_REORDER_BLOCKS, indicate that
> >>> + to fixup_reorder_chain so that it can insert the proper switch text
> >>> + section notes. */
> >>>
> >>> void
> >>> -cfg_layout_finalize (void)
> >>> +cfg_layout_finalize (bool finalize_reorder_blocks)
> >>> {
> >>> #ifdef ENABLE_CHECKING
> >>> verify_flow_info ();
> >>> @@ -3775,7 +3995,7 @@ void
> >>> #endif
> >>> )
> >>> fixup_fallthru_exit_predecessor ();
> >>> - fixup_reorder_chain ();
> >>> + fixup_reorder_chain (finalize_reorder_blocks);
> >>>
> >>> rebuild_jump_labels (get_insns ());
> >>> delete_dead_jumptables ();
> >>> @@ -4454,8 +4674,7 @@ rtl_can_remove_branch_p (const_edge e)
> >>> if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH))
> >>> return false;
> >>>
> >>> - if (find_reg_note (insn, REG_CROSSING_JUMP, NULL_RTX)
> >>> - || BB_PARTITION (src) != BB_PARTITION (target))
> >>> + if (BB_PARTITION (src) != BB_PARTITION (target))
> >>> return false;
> >>>
> >>> if (!onlyjump_p (insn)
> >>>
> >>> --
> >>> This patch is available for review at
> >>> http://codereview.appspot.com/6823047
> >>
> >>
> >>
> >> --
> >> Teresa Johnson | Software Engineer | tejohn...@google.com | 408-460-2413
>
>
>
> --
> Teresa Johnson | Software Engineer | tejohn...@google.com | 408-460-2413
