+2011-07-23 Richard Henderson <rth@redhat.com>
+
+ * basic-block.h (EDGE_PRESERVE): New.
+ (EDGE_ALL_FLAGS, EDGE_COMPLEX): Include it.
+ * bb-reorder.c: Include except.h.
+ (fix_up_crossing_landing_pad): New.
+ (find_rarely_executed_basic_blocks_and_crossing_edges): Place
+ landing pads in the right partition. Duplicate as necessary.
+ (partition_hot_cold_basic_blocks): Fix up DF info after
+ duplicating landing pads.
+ * cfg.c (dump_edge_info): Add crossing and preserve to bitnames.
+ * cfgrtl.c (rtl_verify_flow_info_1): Validate that EDGE_CROSSING
+ is set properly. Validate that EH edges are not CROSSING.
+ * except.c (expand_dw2_landing_pad_for_region): Split out from ...
+ (dw2_build_landing_pads): ... here.
+ (convert_to_eh_region_ranges): Remove code to fixup crossing
+ landing pads.
+ * except.h (expand_dw2_landing_pad_for_region): Declare.
+ * tree-cfg.c (gimple_can_merge_blocks_p): Don't merge PRESERVE edges.
+
2011-07-23 Richard Earnshaw <rearnsha@arm.com>
PR target/49816
$(RTL_H) $(FLAGS_H) $(TIMEVAR_H) output.h $(CFGLAYOUT_H) $(FIBHEAP_H) \
$(TARGET_H) $(FUNCTION_H) $(TM_P_H) $(OBSTACK_H) $(EXPR_H) $(REGS_H) \
$(PARAMS_H) toplev.h $(DIAGNOSTIC_CORE_H) $(TREE_PASS_H) $(DF_H) \
- bb-reorder.h
+ $(EXCEPT_H) bb-reorder.h
tracer.o : tracer.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(RTL_H) \
$(TREE_H) $(BASIC_BLOCK_H) hard-reg-set.h output.h $(CFGLAYOUT_H) \
$(FLAGS_H) $(TIMEVAR_H) $(PARAMS_H) $(COVERAGE_H) $(FIBHEAP_H) \
DEF_VEC_ALLOC_P(edge,gc);
DEF_VEC_ALLOC_P(edge,heap);
-#define EDGE_FALLTHRU 1 /* 'Straight line' flow */
-#define EDGE_ABNORMAL 2 /* Strange flow, like computed
+/* Always update the table in cfg.c dump_edge_info. */
+#define EDGE_FALLTHRU 0x0001 /* 'Straight line' flow */
+#define EDGE_ABNORMAL 0x0002 /* Strange flow, like computed
label, or eh */
-#define EDGE_ABNORMAL_CALL 4 /* Call with abnormal exit
+#define EDGE_ABNORMAL_CALL 0x0004 /* Call with abnormal exit
like an exception, or sibcall */
-#define EDGE_EH 8 /* Exception throw */
-#define EDGE_FAKE 16 /* Not a real edge (profile.c) */
-#define EDGE_DFS_BACK 32 /* A backwards edge */
-#define EDGE_CAN_FALLTHRU 64 /* Candidate for straight line
+#define EDGE_EH 0x0008 /* Exception throw */
+#define EDGE_FAKE 0x0010 /* Not a real edge (profile.c) */
+#define EDGE_DFS_BACK 0x0020 /* A backwards edge */
+#define EDGE_CAN_FALLTHRU 0x0040 /* Candidate for straight line
flow. */
-#define EDGE_IRREDUCIBLE_LOOP 128 /* Part of irreducible loop. */
-#define EDGE_SIBCALL 256 /* Edge from sibcall to exit. */
-#define EDGE_LOOP_EXIT 512 /* Exit of a loop. */
-#define EDGE_TRUE_VALUE 1024 /* Edge taken when controlling
+#define EDGE_IRREDUCIBLE_LOOP 0x0080 /* Part of irreducible loop. */
+#define EDGE_SIBCALL 0x0100 /* Edge from sibcall to exit. */
+#define EDGE_LOOP_EXIT 0x0200 /* Exit of a loop. */
+#define EDGE_TRUE_VALUE 0x0400 /* Edge taken when controlling
predicate is nonzero. */
-#define EDGE_FALSE_VALUE 2048 /* Edge taken when controlling
+#define EDGE_FALSE_VALUE 0x0800 /* Edge taken when controlling
predicate is zero. */
-#define EDGE_EXECUTABLE 4096 /* Edge is executable. Only
+#define EDGE_EXECUTABLE 0x1000 /* Edge is executable. Only
valid during SSA-CCP. */
-#define EDGE_CROSSING 8192 /* Edge crosses between hot
+#define EDGE_CROSSING 0x2000 /* Edge crosses between hot
and cold sections, when we
do partitioning. */
-#define EDGE_ALL_FLAGS 16383
+#define EDGE_PRESERVE 0x4000 /* Never merge blocks via this edge. */
+#define EDGE_ALL_FLAGS 0x7fff
-#define EDGE_COMPLEX (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_EH)
+#define EDGE_COMPLEX \
+ (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_EH | EDGE_PRESERVE)
/* Counter summary from the last set of coverage counts read by
profile.c. */
the compilation, so they are never cleared.
All other flags may be cleared by clear_bb_flags(). It is generally
- a bad idea to rely on any flags being up-to-date. */
+ a bad idea to rely on any flags being up-to-date.
+
+ Always update the table in cfg.c dump_bb_info. */
enum bb_flags
{
#include "tree-pass.h"
#include "df.h"
#include "bb-reorder.h"
+#include "except.h"
/* The number of rounds. In most cases there will only be 4 rounds, but
when partitioning hot and cold basic blocks into separate sections of
return length;
}
+/* Emit a barrier into the footer of BB. */
+
+static void
+emit_barrier_after_bb (basic_block bb)
+{
+ rtx barrier = emit_barrier_after (BB_END (bb));
+ bb->il.rtl->footer = unlink_insn_chain (barrier, barrier);
+}
+
+/* The landing pad OLD_LP, in block OLD_BB, has edges from both partitions.
+ Duplicate the landing pad and split the edges so that no EH edge
+ crosses partitions. */
+
+static void
+fix_up_crossing_landing_pad (eh_landing_pad old_lp, basic_block old_bb)
+{
+ eh_landing_pad new_lp;
+ basic_block new_bb, last_bb, post_bb;
+ rtx new_label, jump, post_label;
+ unsigned new_partition;
+ edge_iterator ei;
+ edge e;
+
+ /* Generate the new landing-pad structure. */
+ new_lp = gen_eh_landing_pad (old_lp->region);
+ new_lp->post_landing_pad = old_lp->post_landing_pad;
+ new_lp->landing_pad = gen_label_rtx ();
+ LABEL_PRESERVE_P (new_lp->landing_pad) = 1;
+
+ /* Put appropriate instructions in new bb. */
+ new_label = emit_label (new_lp->landing_pad);
+
+ expand_dw2_landing_pad_for_region (old_lp->region);
+
+ post_bb = BLOCK_FOR_INSN (old_lp->landing_pad);
+ post_bb = single_succ (post_bb);
+ post_label = block_label (post_bb);
+ jump = emit_jump_insn (gen_jump (post_label));
+ JUMP_LABEL (jump) = post_label;
+
+ /* Create new basic block to be dest for lp. */
+ last_bb = EXIT_BLOCK_PTR->prev_bb;
+ new_bb = create_basic_block (new_label, jump, last_bb);
+ new_bb->aux = last_bb->aux;
+ last_bb->aux = new_bb;
+
+ emit_barrier_after_bb (new_bb);
+
+ make_edge (new_bb, post_bb, 0);
+
+ /* Make sure new bb is in the other partition. */
+ new_partition = BB_PARTITION (old_bb);
+ new_partition ^= BB_HOT_PARTITION | BB_COLD_PARTITION;
+ BB_SET_PARTITION (new_bb, new_partition);
+
+ /* Fix up the edges. */
+ for (ei = ei_start (old_bb->preds); (e = ei_safe_edge (ei)) != NULL; )
+ if (BB_PARTITION (e->src) == new_partition)
+ {
+ rtx insn = BB_END (e->src);
+ rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX);
+
+ gcc_assert (note != NULL);
+ gcc_checking_assert (INTVAL (XEXP (note, 0)) == old_lp->index);
+ XEXP (note, 0) = GEN_INT (new_lp->index);
+
+ /* Adjust the edge to the new destination. */
+ redirect_edge_succ (e, new_bb);
+ }
+ else
+ ei_next (&ei);
+}
+
/* Find the basic blocks that are rarely executed and need to be moved to
a separate section of the .o file (to cut down on paging and improve
cache locality). Return a vector of all edges that cross. */
edge_iterator ei;
/* Mark which partition (hot/cold) each basic block belongs in. */
-
FOR_EACH_BB (bb)
{
if (probably_never_executed_bb_p (bb))
BB_SET_PARTITION (bb, BB_HOT_PARTITION);
}
- /* Mark every edge that crosses between sections. */
-
- FOR_EACH_BB (bb)
- FOR_EACH_EDGE (e, ei, bb->succs)
+ /* 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. */
+ if (cfun->eh->lp_array)
{
- if (e->src != ENTRY_BLOCK_PTR
- && e->dest != EXIT_BLOCK_PTR
- && BB_PARTITION (e->src) != BB_PARTITION (e->dest))
+ unsigned i;
+ eh_landing_pad lp;
+
+ FOR_EACH_VEC_ELT (eh_landing_pad, cfun->eh->lp_array, i, lp)
{
- e->flags |= EDGE_CROSSING;
- VEC_safe_push (edge, heap, crossing_edges, e);
+ bool all_same, all_diff;
+
+ if (lp == NULL)
+ continue;
+
+ all_same = all_diff = true;
+ bb = BLOCK_FOR_INSN (lp->landing_pad);
+ FOR_EACH_EDGE (e, ei, bb->preds)
+ {
+ gcc_assert (e->flags & EDGE_EH);
+ if (BB_PARTITION (bb) == BB_PARTITION (e->src))
+ all_diff = false;
+ else
+ all_same = false;
+ }
+
+ if (all_same)
+ ;
+ else if (all_diff)
+ {
+ int which = BB_PARTITION (bb);
+ which ^= BB_HOT_PARTITION | BB_COLD_PARTITION;
+ BB_SET_PARTITION (bb, which);
+ }
+ else
+ fix_up_crossing_landing_pad (lp, bb);
}
- else
- e->flags &= ~EDGE_CROSSING;
}
- return crossing_edges;
-}
+ /* Mark every edge that crosses between sections. */
-/* Emit a barrier into the footer of BB. */
+ FOR_EACH_BB (bb)
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ {
+ unsigned int flags = e->flags;
+
+ /* We should never have EDGE_CROSSING set yet. */
+ gcc_checking_assert ((flags & EDGE_CROSSING) == 0);
+
+ if (e->src != ENTRY_BLOCK_PTR
+ && e->dest != EXIT_BLOCK_PTR
+ && BB_PARTITION (e->src) != BB_PARTITION (e->dest))
+ {
+ VEC_safe_push (edge, heap, crossing_edges, e);
+ flags |= EDGE_CROSSING;
+ }
-static void
-emit_barrier_after_bb (basic_block bb)
-{
- rtx barrier = emit_barrier_after (BB_END (bb));
- bb->il.rtl->footer = unlink_insn_chain (barrier, barrier);
+ /* Now that we've split eh edges as appropriate, allow landing pads
+ to be merged with the post-landing pads. */
+ flags &= ~EDGE_PRESERVE;
+
+ e->flags = flags;
+ }
+
+ return crossing_edges;
}
/* If any destination of a crossing edge does not have a label, add label;
if (n_basic_blocks <= NUM_FIXED_BLOCKS + 1)
return 0;
+ df_set_flags (DF_DEFER_INSN_RESCAN);
+
crossing_edges = find_rarely_executed_basic_blocks_and_crossing_edges ();
if (crossing_edges == NULL)
return 0;
VEC_free (edge, heap, crossing_edges);
+ /* ??? FIXME: DF generates the bb info for a block immediately.
+ And by immediately, I mean *during* creation of the block.
+
+ #0 df_bb_refs_collect
+ #1 in df_bb_refs_record
+ #2 in create_basic_block_structure
+
+ Which means that the bb_has_eh_pred test in df_bb_refs_collect
+ will *always* fail, because no edges can have been added to the
+ block yet. Which of course means we don't add the right
+ artificial refs, which means we fail df_verify (much) later.
+
+ Cleanest solution would seem to make DF_DEFER_INSN_RESCAN imply
+ that we also shouldn't grab data from the new blocks those new
+ insns are in either. In this way one can create the block, link
+ it up properly, and have everything Just Work later, when deferred
+ insns are processed.
+
+ In the meantime, we have no other option but to throw away all
+ of the DF data and recompute it all. */
+ if (cfun->eh->lp_array)
+ {
+ df_finish_pass (true);
+ df_scan_alloc (NULL);
+ df_scan_blocks ();
+ /* Not all post-landing pads use all of the EH_RETURN_DATA_REGNO
+ data. We blindly generated all of them when creating the new
+ landing pad. Delete those assignments we don't use. */
+ df_set_flags (DF_LR_RUN_DCE);
+ df_analyze ();
+ }
+
return TODO_verify_flow | TODO_verify_rtl_sharing;
}
\f
static const char * const bitnames[] = {
"fallthru", "ab", "abcall", "eh", "fake", "dfs_back",
"can_fallthru", "irreducible", "sibcall", "loop_exit",
- "true", "false", "exec"
+ "true", "false", "exec", "crossing", "preserve"
};
int comma = 0;
int i, flags = e->flags;
}
FOR_EACH_EDGE (e, ei, bb->succs)
{
+ bool is_crossing;
+
if (e->flags & EDGE_FALLTHRU)
+ n_fallthru++, fallthru = e;
+
+ is_crossing = (BB_PARTITION (e->src) != BB_PARTITION (e->dest)
+ && e->src != ENTRY_BLOCK_PTR
+ && e->dest != EXIT_BLOCK_PTR);
+ if (e->flags & EDGE_CROSSING)
{
- n_fallthru++, fallthru = e;
- if ((e->flags & EDGE_CROSSING)
- || (BB_PARTITION (e->src) != BB_PARTITION (e->dest)
- && e->src != ENTRY_BLOCK_PTR
- && e->dest != EXIT_BLOCK_PTR))
- {
+ if (!is_crossing)
+ {
+ error ("EDGE_CROSSING incorrectly set across same section");
+ err = 1;
+ }
+ if (e->flags & EDGE_FALLTHRU)
+ {
error ("fallthru edge crosses section boundary (bb %i)",
e->src->index);
err = 1;
}
+ if (e->flags & EDGE_EH)
+ {
+ error ("EH edge crosses section boundary (bb %i)",
+ e->src->index);
+ err = 1;
+ }
+ }
+ else if (is_crossing)
+ {
+ error ("EDGE_CROSSING missing across section boundary");
+ err = 1;
}
if ((e->flags & ~(EDGE_DFS_BACK
return bb;
}
\f
+/* A subroutine of dw2_build_landing_pads, also used for edge splitting
+ at the rtl level. Emit the code required by the target at a landing
+ pad for the given region. */
+
+void
+expand_dw2_landing_pad_for_region (eh_region region)
+{
+#ifdef HAVE_exception_receiver
+ if (HAVE_exception_receiver)
+ emit_insn (gen_exception_receiver ());
+ else
+#endif
+#ifdef HAVE_nonlocal_goto_receiver
+ if (HAVE_nonlocal_goto_receiver)
+ emit_insn (gen_nonlocal_goto_receiver ());
+ else
+#endif
+ { /* Nothing */ }
+
+ if (region->exc_ptr_reg)
+ emit_move_insn (region->exc_ptr_reg,
+ gen_rtx_REG (ptr_mode, EH_RETURN_DATA_REGNO (0)));
+ if (region->filter_reg)
+ emit_move_insn (region->filter_reg,
+ gen_rtx_REG (targetm.eh_return_filter_mode (),
+ EH_RETURN_DATA_REGNO (1)));
+}
+
/* Expand the extra code needed at landing pads for dwarf2 unwinding. */
static void
{
int i;
eh_landing_pad lp;
+ int e_flags = EDGE_FALLTHRU;
+
+ /* If we're going to partition blocks, we need to be able to add
+ new landing pads later, which means that we need to hold on to
+ the post-landing-pad block. Prevent it from being merged away.
+ We'll remove this bit after partitioning. */
+ if (flag_reorder_blocks_and_partition)
+ e_flags |= EDGE_PRESERVE;
for (i = 1; VEC_iterate (eh_landing_pad, cfun->eh->lp_array, i, lp); ++i)
{
- eh_region region;
basic_block bb;
rtx seq;
edge e;
emit_label (lp->landing_pad);
LABEL_PRESERVE_P (lp->landing_pad) = 1;
-#ifdef HAVE_exception_receiver
- if (HAVE_exception_receiver)
- emit_insn (gen_exception_receiver ());
- else
-#endif
-#ifdef HAVE_nonlocal_goto_receiver
- if (HAVE_nonlocal_goto_receiver)
- emit_insn (gen_nonlocal_goto_receiver ());
- else
-#endif
- { /* Nothing */ }
-
- region = lp->region;
- if (region->exc_ptr_reg)
- emit_move_insn (region->exc_ptr_reg,
- gen_rtx_REG (ptr_mode, EH_RETURN_DATA_REGNO (0)));
- if (region->filter_reg)
- emit_move_insn (region->filter_reg,
- gen_rtx_REG (targetm.eh_return_filter_mode (),
- EH_RETURN_DATA_REGNO (1)));
+ expand_dw2_landing_pad_for_region (lp->region);
seq = get_insns ();
end_sequence ();
bb = emit_to_new_bb_before (seq, label_rtx (lp->post_landing_pad));
- e = make_edge (bb, bb->next_bb, EDGE_FALLTHRU);
+ e = make_edge (bb, bb->next_bb, e_flags);
e->count = bb->count;
e->probability = REG_BR_PROB_BASE;
}
rtx section_switch_note = NULL_RTX;
rtx first_no_action_insn_before_switch = NULL_RTX;
rtx last_no_action_insn_before_switch = NULL_RTX;
- rtx *pad_map = NULL;
- sbitmap pad_loc = NULL;
- int min_labelno = 0, max_labelno = 0;
int saved_call_site_base = call_site_base;
crtl->eh.action_record_data = VEC_alloc (uchar, gc, 64);
gcc_assert (crtl->eh.call_site_record[cur_sec] == NULL);
crtl->eh.call_site_record[cur_sec]
= VEC_alloc (call_site_record, gc, 10);
- max_labelno = max_label_num ();
- min_labelno = get_first_label_num ();
- pad_map = XCNEWVEC (rtx, max_labelno - min_labelno + 1);
- pad_loc = sbitmap_alloc (max_labelno - min_labelno + 1);
}
- else if (LABEL_P (iter) && pad_map)
- SET_BIT (pad_loc, CODE_LABEL_NUMBER (iter) - min_labelno);
if (last_action >= -1 && ! first_no_action_insn)
{
call_site_base = saved_call_site_base;
- if (pad_map)
- {
- /* When doing hot/cold partitioning, ensure landing pads are
- always in the same section as the EH region, .gcc_except_table
- can't express it otherwise. */
- for (cur_sec = 0; cur_sec < 2; cur_sec++)
- {
- int i, idx;
- int n = VEC_length (call_site_record,
- crtl->eh.call_site_record[cur_sec]);
- basic_block prev_bb = NULL, padbb;
-
- for (i = 0; i < n; ++i)
- {
- struct call_site_record_d *cs =
- VEC_index (call_site_record,
- crtl->eh.call_site_record[cur_sec], i);
- rtx jump, note;
-
- if (cs->landing_pad == NULL_RTX)
- continue;
- idx = CODE_LABEL_NUMBER (cs->landing_pad) - min_labelno;
- /* If the landing pad is in the correct section, nothing
- is needed. */
- if (TEST_BIT (pad_loc, idx) ^ (cur_sec == 0))
- continue;
- /* Otherwise, if we haven't seen this pad yet, we need to
- add a new label and jump to the correct section. */
- if (pad_map[idx] == NULL_RTX)
- {
- pad_map[idx] = gen_label_rtx ();
- if (prev_bb == NULL)
- for (iter = section_switch_note;
- iter; iter = PREV_INSN (iter))
- if (NOTE_INSN_BASIC_BLOCK_P (iter))
- {
- prev_bb = NOTE_BASIC_BLOCK (iter);
- break;
- }
- if (cur_sec == 0)
- {
- note = emit_label_before (pad_map[idx],
- section_switch_note);
- jump = emit_jump_insn_before (gen_jump (cs->landing_pad),
- section_switch_note);
- }
- else
- {
- jump = emit_jump_insn_after (gen_jump (cs->landing_pad),
- section_switch_note);
- note = emit_label_after (pad_map[idx],
- section_switch_note);
- }
- JUMP_LABEL (jump) = cs->landing_pad;
- add_reg_note (jump, REG_CROSSING_JUMP, NULL_RTX);
- iter = NEXT_INSN (cs->landing_pad);
- if (iter && NOTE_INSN_BASIC_BLOCK_P (iter))
- padbb = NOTE_BASIC_BLOCK (iter);
- else
- padbb = NULL;
- if (padbb && prev_bb
- && BB_PARTITION (padbb) != BB_UNPARTITIONED)
- {
- basic_block bb;
- int part
- = BB_PARTITION (padbb) == BB_COLD_PARTITION
- ? BB_HOT_PARTITION : BB_COLD_PARTITION;
- edge_iterator ei;
- edge e;
-
- bb = create_basic_block (note, jump, prev_bb);
- make_single_succ_edge (bb, padbb, EDGE_CROSSING);
- BB_SET_PARTITION (bb, part);
- for (ei = ei_start (padbb->preds);
- (e = ei_safe_edge (ei)); )
- {
- if ((e->flags & (EDGE_EH|EDGE_CROSSING))
- == (EDGE_EH|EDGE_CROSSING))
- {
- redirect_edge_succ (e, bb);
- e->flags &= ~EDGE_CROSSING;
- }
- else
- ei_next (&ei);
- }
- if (cur_sec == 0)
- prev_bb = bb;
- }
- }
- cs->landing_pad = pad_map[idx];
- }
- }
-
- sbitmap_free (pad_loc);
- XDELETEVEC (pad_map);
- }
-
htab_delete (ar_hash);
return 0;
}
extern void expand_builtin_eh_return (tree, tree);
extern void expand_eh_return (void);
extern rtx expand_builtin_extend_pointer (tree);
+extern void expand_dw2_landing_pad_for_region (eh_region);
typedef tree (*duplicate_eh_regions_map) (tree, void *);
extern struct pointer_map_t *duplicate_eh_regions
if (!single_succ_p (a))
return false;
- if (single_succ_edge (a)->flags & (EDGE_ABNORMAL | EDGE_EH))
+ if (single_succ_edge (a)->flags & (EDGE_ABNORMAL | EDGE_EH | EDGE_PRESERVE))
return false;
if (single_succ (a) != b)
projects / gcc.git / commitdiff