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-rw-r--r--gcc/ChangeLog21
-rw-r--r--gcc/basic-block.h10
-rw-r--r--gcc/flow.c23
-rw-r--r--gcc/predict.c19
-rw-r--r--gcc/sbitmap.c38
-rw-r--r--gcc/sbitmap.h3
6 files changed, 100 insertions, 14 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8f43f07..fa19a6d 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,24 @@
+Fri Jan 7 19:48:04 CET 2000 Jan Hubicka <jh@suse.cz>
+ * sbitmap.c (sbitmap_first_set_bit, sbitmap_last_set_bit): New
+ function.
+ * sbitmap.h (sbitmap_first_set_bit, sbitmap_last_set_bit): Declare.
+ * basic_block.h (FLOW_LOOP_FIRST_BLOCK): New macro.
+ (FLOW_LOOP_LAST_BLOCK): Likewise.
+
+2000-01-21 Michael Hayes <m.hayes@elec.canterbury.ac.nz>
+
+ * basic-block.h (struct loop): New fields 'first' and 'last'.
+ * flow.c (flow_loops_find): Compute loop->first and loop->last.
+ (flow_loops_dump): Use loop->first to check for NOTE_INSN_LOOP_BEG
+ and loop->last to check for NOTE_INSN_LOOP_END.
+
+Fri Jan 28 10:57:58 2000 Jason Eckhardt <jle@cygnus.com>
+
+ * predict.c (estimate_probability): Use the new FIRST and LAST fields
+ of the loop descriptor rather than HEADER and LATCH. Also added
+ missing break statements as well making some coding style modifications
+ as suggested by Michael Hayes.
+
2000-01-28 Richard Henderson <rth@cygnus.com>
* flow.c (find_basic_blocks): Remove do_cleanup argument.
diff --git a/gcc/basic-block.h b/gcc/basic-block.h
index a4e970d..57fb2a7f 100644
--- a/gcc/basic-block.h
+++ b/gcc/basic-block.h
@@ -239,6 +239,14 @@ struct loop
/* Basic block of loop pre-header or NULL if it does not exist. */
basic_block pre_header;
+ /* The first block in the loop. This is not necessarily the same as
+ the loop header. */
+ basic_block first;
+
+ /* The last block in the loop. This is not necessarily the same as
+ the loop latch. */
+ basic_block last;
+
/* Bitmap of blocks contained within the loop. */
sbitmap nodes;
@@ -318,6 +326,8 @@ struct loop
int exit_count;
};
+#define FLOW_LOOP_FIRST_BLOCK(loop) sbitmap_first_set_bit ((loop).nodes)
+#define FLOW_LOOP_LAST_BLOCK(loop) sbitmap_last_set_bit ((loop).nodes)
/* Structure to hold CFG information about natural loops within a function. */
struct loops
diff --git a/gcc/flow.c b/gcc/flow.c
index 0578bef..73a967b 100644
--- a/gcc/flow.c
+++ b/gcc/flow.c
@@ -6465,16 +6465,16 @@ flow_loops_dump (loops, file, verbose)
{
/* Print diagnostics to compare our concept of a loop with
what the loop notes say. */
- if (GET_CODE (PREV_INSN (loop->header->head)) != NOTE
- || NOTE_LINE_NUMBER (PREV_INSN (loop->header->head))
+ if (GET_CODE (PREV_INSN (loop->first->head)) != NOTE
+ || NOTE_LINE_NUMBER (PREV_INSN (loop->first->head))
!= NOTE_INSN_LOOP_BEG)
fprintf (file, ";; No NOTE_INSN_LOOP_BEG at %d\n",
- INSN_UID (PREV_INSN (loop->header->head)));
- if (GET_CODE (NEXT_INSN (loop->latch->end)) != NOTE
- || NOTE_LINE_NUMBER (NEXT_INSN (loop->latch->end))
+ INSN_UID (PREV_INSN (loop->first->head)));
+ if (GET_CODE (NEXT_INSN (loop->last->end)) != NOTE
+ || NOTE_LINE_NUMBER (NEXT_INSN (loop->last->end))
!= NOTE_INSN_LOOP_END)
fprintf (file, ";; No NOTE_INSN_LOOP_END at %d\n",
- INSN_UID (NEXT_INSN (loop->latch->end)));
+ INSN_UID (NEXT_INSN (loop->last->end)));
}
}
@@ -6975,7 +6975,16 @@ flow_loops_find (loops)
loop->nodes = sbitmap_alloc (n_basic_blocks);
loop->num_nodes
= flow_loop_nodes_find (header, latch, loop->nodes);
-
+
+ /* Compute first and last blocks within the loop.
+ These are often the same as the loop header and
+ loop latch respectively, but this is not always
+ the case. */
+ loop->first
+ = BASIC_BLOCK (sbitmap_first_set_bit (loop->nodes));
+ loop->last
+ = BASIC_BLOCK (sbitmap_last_set_bit (loop->nodes));
+
/* Find edges which exit the loop. Note that a node
may have several exit edges. */
loop->num_exits
diff --git a/gcc/predict.c b/gcc/predict.c
index 1846b4a..d8a588f 100644
--- a/gcc/predict.c
+++ b/gcc/predict.c
@@ -53,7 +53,7 @@
??? In the next revision there will be a number of other predictors added
from the above references. Further, each heuristic will be factored out
into its own function for clarity (and to facilitate the combination of
- predictions). */
+ predictions). */
void
estimate_probability (loops_info)
@@ -61,13 +61,14 @@ estimate_probability (loops_info)
{
int i;
- /* Try to predict out blocks in a loop that are not part of a natural loop */
+ /* Try to predict out blocks in a loop that are not part of a
+ natural loop. */
for (i = 0; i < loops_info->num; i++)
{
int j;
- for (j = loops_info->array[i].header->index;
- j <= loops_info->array[i].latch->index;
+ for (j = loops_info->array[i].first->index;
+ j <= loops_info->array[i].last->index;
++j)
{
edge e;
@@ -83,17 +84,18 @@ estimate_probability (loops_info)
|| ! condjump_p (last_insn) || simplejump_p (last_insn))
continue;
cond = get_condition (last_insn, &earliest);
- if (!cond)
+ if (! cond)
continue;
if (! find_reg_note (last_insn, REG_BR_PROB, 0))
REG_NOTES (last_insn)
- = gen_rtx_EXPR_LIST (REG_BR_PROB, GEN_INT (REG_BR_PROB_BASE),
+ = gen_rtx_EXPR_LIST (REG_BR_PROB,
+ GEN_INT (REG_BR_PROB_BASE),
REG_NOTES (last_insn));
}
}
}
- /* Try to predict condjumps using same algorithm as mostly_true_jump */
+ /* Try to predict condjumps using same algorithm as mostly_true_jump. */
for (i = 0; i < n_basic_blocks - 1; i++)
{
rtx last_insn = BLOCK_END (i);
@@ -114,10 +116,13 @@ estimate_probability (loops_info)
case CONST_INT:
/* Unconditional branch. */
prob = REG_BR_PROB_BASE / 2;
+ break;
case EQ:
prob = REG_BR_PROB_BASE / 10;
+ break;
case NE:
prob = REG_BR_PROB_BASE / 2;
+ break;
case LE:
case LT:
if (XEXP (cond, 1) == const0_rtx)
diff --git a/gcc/sbitmap.c b/gcc/sbitmap.c
index dece5e5..0046c57 100644
--- a/gcc/sbitmap.c
+++ b/gcc/sbitmap.c
@@ -497,6 +497,44 @@ sbitmap_union_of_preds (dst, src, bb)
}
}
+/* Return number of first bit set in the bitmap, -1 if none. */
+
+int
+sbitmap_first_set_bit (bmap)
+ sbitmap bmap;
+{
+ int n;
+ EXECUTE_IF_SET_IN_SBITMAP (bmap, 0, n, { return n; });
+ return -1;
+}
+
+/* Return number of last bit set in the bitmap, -1 if none. */
+
+int
+sbitmap_last_set_bit (bmap)
+ sbitmap bmap;
+{
+ int i;
+ SBITMAP_ELT_TYPE *ptr = bmap->elms;
+ for (i = bmap->size - 1; i >= 0; i--)
+ {
+ SBITMAP_ELT_TYPE word = ptr[i];
+ if (word)
+ {
+ int index = (i + 1) * SBITMAP_ELT_BITS - 1;
+ SBITMAP_ELT_TYPE mask = (SBITMAP_ELT_TYPE) 1 << (SBITMAP_ELT_BITS - 1);
+ while (1)
+ {
+ if (word & mask)
+ return index;
+ mask >>= 1;
+ index--;
+ }
+ }
+ }
+ return -1;
+}
+
void
dump_sbitmap (file, bmap)
FILE *file;
diff --git a/gcc/sbitmap.h b/gcc/sbitmap.h
index f459ed0..d506546 100644
--- a/gcc/sbitmap.h
+++ b/gcc/sbitmap.h
@@ -114,6 +114,9 @@ extern int sbitmap_a_and_b PARAMS ((sbitmap, sbitmap, sbitmap));
extern int sbitmap_a_or_b PARAMS ((sbitmap, sbitmap, sbitmap));
extern int sbitmap_a_subset_b_p PARAMS ((sbitmap, sbitmap));
+extern int sbitmap_first_set_bit PROTO ((sbitmap));
+extern int sbitmap_last_set_bit PROTO ((sbitmap));
+
struct int_list;
extern void sbitmap_intersect_of_predsucc PARAMS ((sbitmap, sbitmap *,
int, struct int_list **));
generated by cgit v1.1 at 2025-12-25 03:30:04 +0000