From a686dbf86a80b697e84a8ea9a8fa94b281796557 Mon Sep 17 00:00:00 2001
From: Jan Hubicka <jh@suse.cz>
Date: Sat, 24 Feb 2001 03:32:33 +0100
Subject: [PATCH] flow.c (find_sub_basic_blocks): New function.
* flow.c (find_sub_basic_blocks): New function.
(split_block): Be ready for basic block introduced by CODE_LABEL.
(commit_one_edge_insertion): Call find_sub_basic_block.
* flow.c (make_edges): Add edge from entry for blocks starting with
label having ALTERNATE_NAME
From-SVN: r40021
---
gcc/ChangeLog | 9 ++++
gcc/flow.c | 126 ++++++++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 130 insertions(+), 5 deletions(-)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e0359670eb3e..d3f1da5600ff 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+Sat Feb 24 03:30:38 CET 2001 Jan Hubicka <jh@suse.cz>
+
+ * flow.c (find_sub_basic_blocks): New function.
+ (split_block): Be ready for basic block introduced by CODE_LABEL.
+ (commit_one_edge_insertion): Call find_sub_basic_block.
+
+ * flow.c (make_edges): Add edge from entry for blocks starting with
+ label having ALTERNATE_NAME
+
Sat Feb 24 03:19:42 CET 2001 Jan Hubicka <jh@suse.cz>
* function.c (epilogue_done): Be ready for first basic block not
diff --git a/gcc/flow.c b/gcc/flow.c
index 10c1bd2d3f84..82e90174063a 100644
--- a/gcc/flow.c
+++ b/gcc/flow.c
@@ -473,6 +473,7 @@ static void flow_loops_tree_build PARAMS ((struct loops *));
static int flow_loop_level_compute PARAMS ((struct loop *, int));
static int flow_loops_level_compute PARAMS ((struct loops *));
static void allocate_bb_life_data PARAMS ((void));
+static void find_sub_basic_blocks PARAMS ((basic_block));
/* Find basic blocks of the current function.
F is the first insn of the function and NREGS the number of register
@@ -697,6 +698,106 @@ find_label_refs (f, lvl)
return lvl;
}
+/* Assume that someone emitted code with control flow instructions to the
+ basic block. Update the data structure. */
+static void
+find_sub_basic_blocks (bb)
+ basic_block bb;
+{
+ rtx first_insn = bb->head, insn;
+ rtx end = bb->end;
+ edge succ_list = bb->succ;
+ rtx jump_insn = NULL_RTX;
+ int created = 0;
+ int barrier = 0;
+ edge falltru = 0;
+ basic_block first_bb = bb, last_bb;
+ int i;
+
+ if (GET_CODE (first_insn) == LABEL_REF)
+ first_insn = NEXT_INSN (first_insn);
+ first_insn = NEXT_INSN (first_insn);
+ bb->succ = NULL;
+
+ insn = first_insn;
+ /* Scan insn chain and try to find new basic block boundaries. */
+ while (insn != end)
+ {
+ enum rtx_code code = GET_CODE (insn);
+ switch (code)
+ {
+ case JUMP_INSN:
+ /* We need some special care for those expressions. */
+ if (GET_CODE (PATTERN (insn)) == ADDR_VEC
+ || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)
+ abort();
+ jump_insn = insn;
+ break;
+ case BARRIER:
+ if (!jump_insn)
+ abort ();
+ barrier = 1;
+ break;
+ /* On code label, split current basic block. */
+ case CODE_LABEL:
+ falltru = split_block (bb, PREV_INSN (insn));
+ if (jump_insn)
+ bb->end = jump_insn;
+ bb = falltru->dest;
+ if (barrier)
+ remove_edge (falltru);
+ barrier = 0;
+ jump_insn = 0;
+ created = 1;
+ if (LABEL_ALTERNATE_NAME (insn))
+ make_edge (NULL, ENTRY_BLOCK_PTR, bb, 0);
+ break;
+ case INSN:
+ /* In case we've previously split insn on the JUMP_INSN, move the
+ block header to proper place. */
+ if (jump_insn)
+ {
+ falltru = split_block (bb, PREV_INSN (insn));
+ bb->end = jump_insn;
+ bb = falltru->dest;
+ if (barrier)
+ abort ();
+ jump_insn = 0;
+ }
+ default:
+ break;
+ }
+ insn = NEXT_INSN (insn);
+ }
+ /* Last basic block must end in the original BB end. */
+ if (jump_insn)
+ abort ();
+
+ /* Wire in the original edges for last basic block. */
+ if (created)
+ {
+ bb->succ = succ_list;
+ while (succ_list)
+ succ_list->src = bb, succ_list = succ_list->succ_next;
+ }
+ else
+ bb->succ = succ_list;
+
+ /* Now re-scan and wire in all edges. This expect simple (conditional)
+ jumps at the end of each new basic blocks. */
+ last_bb = bb;
+ for (i = first_bb->index; i < last_bb->index; i++)
+ {
+ bb = BASIC_BLOCK (i);
+ if (GET_CODE (bb->end) == JUMP_INSN)
+ {
+ mark_jump_label (PATTERN (bb->end), bb->end, 0, 0);
+ make_label_edge (NULL, bb, JUMP_LABEL (bb->end), 0);
+ }
+ insn = NEXT_INSN (insn);
+ }
+}
+
/* Find all basic blocks of the function whose first insn is F.
Collect and return a list of labels whose addresses are taken. This
@@ -1121,6 +1222,10 @@ make_edges (label_value_list)
enum rtx_code code;
int force_fallthru = 0;
+ if (GET_CODE (bb->head) == CODE_LABEL
+ && LABEL_ALTERNATE_NAME (bb->head))
+ make_edge (NULL, ENTRY_BLOCK_PTR, bb, 0);
+
/* Examine the last instruction of the block, and discover the
ways we can leave the block. */
@@ -1589,11 +1694,21 @@ split_block (bb, insn)
BASIC_BLOCK (i) = new_bb;
new_bb->index = i;
- /* Create the basic block note. */
- bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK,
- new_bb->head);
- NOTE_BASIC_BLOCK (bb_note) = new_bb;
- new_bb->head = bb_note;
+ if (GET_CODE (new_bb->head) == CODE_LABEL)
+ {
+ /* Create the basic block note. */
+ bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK,
+ new_bb->head);
+ NOTE_BASIC_BLOCK (bb_note) = new_bb;
+ }
+ else
+ {
+ /* Create the basic block note. */
+ bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK,
+ new_bb->head);
+ NOTE_BASIC_BLOCK (bb_note) = new_bb;
+ new_bb->head = bb_note;
+ }
update_bb_for_insn (new_bb);
@@ -1995,6 +2110,7 @@ commit_one_edge_insertion (e)
}
else if (GET_CODE (last) == JUMP_INSN)
abort ();
+ find_sub_basic_blocks (bb);
}
/* Update the CFG for all queued instructions. */
--
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