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[PATCH] Improve memory usage on PR64928
- From: Richard Biener <rguenther at suse dot de>
- To: gcc-patches at gcc dot gnu dot org
- Date: Thu, 5 Mar 2015 17:04:43 +0100 (CET)
- Subject: [PATCH] Improve memory usage on PR64928
- Authentication-results: sourceware.org; auth=none
I am currently testing the following patch to reduce peak memory
usage of the out-of-SSA phase for the testcase in the PR. The
issue is (as usual) big live and SSA conflict graph memory use.
This side tackles live info and frees livein before computing
the conflict graph (which only needs liveout).
Bootstrap and regtest ongoing on x86_64-unknown-linux-gnu.
Richard.
2015-03-05 Richard Biener <rguenther@suse.de>
PR middle-end/64928
* tree-ssa-live.h (struct tree_live_info_d): Add livein_obstack
and liveout_obstack members.
(calculate_live_on_exit): Remove.
(delete_tree_live_info_livein): Declare.
(delete_tree_live_info_liveout): Likewise.
* tree-ssa-live.c (liveness_bitmap_obstack): Remove global var.
(new_tree_live_info): Adjust.
(delete_tree_live_info_livein): New function.
(delete_tree_live_info_liveout): Likewise.
(delete_tree_live_info): Deal with partly deleted live info.
(loe_visit_block): Remove temporary bitmap by using
bitmap_ior_and_compl_into.
(live_worklist): Adjust accordingly.
(calculate_live_on_exit): Make static.
(calculate_live_ranges): Do not initialize liveness_bitmap_obstack.
Index: gcc/tree-ssa-coalesce.c
===================================================================
--- gcc/tree-ssa-coalesce.c (revision 221205)
+++ gcc/tree-ssa-coalesce.c (working copy)
@@ -1345,6 +1345,7 @@ coalesce_ssa_name (void)
dump_var_map (dump_file, map);
liveinfo = calculate_live_ranges (map);
+ delete_tree_live_info_livein (liveinfo);
if (dump_file && (dump_flags & TDF_DETAILS))
dump_live_info (dump_file, liveinfo, LIVEDUMP_ENTRY);
Index: gcc/tree-ssa-live.c
===================================================================
--- gcc/tree-ssa-live.c (revision 221205)
+++ gcc/tree-ssa-live.c (working copy)
@@ -973,13 +973,6 @@ remove_unused_locals (void)
timevar_pop (TV_REMOVE_UNUSED);
}
-/* Obstack for globale liveness info bitmaps. We don't want to put these
- on the default obstack because these bitmaps can grow quite large and
- we'll hold on to all that memory until the end of the compiler run.
- As a bonus, delete_tree_live_info can destroy all the bitmaps by just
- releasing the whole obstack. */
-static bitmap_obstack liveness_bitmap_obstack;
-
/* Allocate and return a new live range information object base on MAP. */
static tree_live_info_p
@@ -992,31 +985,61 @@ new_tree_live_info (var_map map)
live->map = map;
live->num_blocks = last_basic_block_for_fn (cfun);
+ bitmap_obstack_initialize (&live->livein_obstack);
+ bitmap_obstack_initialize (&live->liveout_obstack);
live->livein = XNEWVEC (bitmap_head, last_basic_block_for_fn (cfun));
FOR_EACH_BB_FN (bb, cfun)
- bitmap_initialize (&live->livein[bb->index], &liveness_bitmap_obstack);
+ bitmap_initialize (&live->livein[bb->index], &live->livein_obstack);
live->liveout = XNEWVEC (bitmap_head, last_basic_block_for_fn (cfun));
FOR_EACH_BB_FN (bb, cfun)
- bitmap_initialize (&live->liveout[bb->index], &liveness_bitmap_obstack);
+ bitmap_initialize (&live->liveout[bb->index], &live->liveout_obstack);
live->work_stack = XNEWVEC (int, last_basic_block_for_fn (cfun));
live->stack_top = live->work_stack;
- live->global = BITMAP_ALLOC (&liveness_bitmap_obstack);
+ live->global = BITMAP_ALLOC (NULL);
return live;
}
+/* Free storage for livein of the live range info object LIVE. */
+
+void
+delete_tree_live_info_livein (tree_live_info_p live)
+{
+ bitmap_obstack_release (&live->livein_obstack);
+ free (live->livein);
+ live->livein = NULL;
+}
+
+/* Free storage for liveout of the live range info object LIVE. */
+
+void
+delete_tree_live_info_liveout (tree_live_info_p live)
+{
+ bitmap_obstack_release (&live->liveout_obstack);
+ free (live->liveout);
+ live->liveout = NULL;
+}
+
/* Free storage for live range info object LIVE. */
void
delete_tree_live_info (tree_live_info_p live)
{
- bitmap_obstack_release (&liveness_bitmap_obstack);
+ if (live->livein)
+ {
+ bitmap_obstack_release (&live->livein_obstack);
+ free (live->livein);
+ }
+ if (live->liveout)
+ {
+ bitmap_obstack_release (&live->liveout_obstack);
+ free (live->liveout);
+ }
+ BITMAP_FREE (live->global);
free (live->work_stack);
- free (live->liveout);
- free (live->livein);
free (live);
}
@@ -1027,8 +1050,7 @@ delete_tree_live_info (tree_live_info_p
it each time. */
static void
-loe_visit_block (tree_live_info_p live, basic_block bb, sbitmap visited,
- bitmap tmp)
+loe_visit_block (tree_live_info_p live, basic_block bb, sbitmap visited)
{
edge e;
bool change;
@@ -1046,17 +1068,17 @@ loe_visit_block (tree_live_info_p live,
pred_bb = e->src;
if (pred_bb == ENTRY_BLOCK_PTR_FOR_FN (cfun))
continue;
- /* TMP is variables live-on-entry from BB that aren't defined in the
+ /* Variables live-on-entry from BB that aren't defined in the
predecessor block. This should be the live on entry vars to pred.
Note that liveout is the DEFs in a block while live on entry is
- being calculated. */
- bitmap_and_compl (tmp, loe, &live->liveout[pred_bb->index]);
-
- /* Add these bits to live-on-entry for the pred. if there are any
+ being calculated.
+ Add these bits to live-on-entry for the pred. if there are any
changes, and pred_bb has been visited already, add it to the
revisit stack. */
- change = bitmap_ior_into (live_on_entry (live, pred_bb), tmp);
- if (bitmap_bit_p (visited, pred_bb->index) && change)
+ change = bitmap_ior_and_compl_into (live_on_entry (live, pred_bb),
+ loe, &live->liveout[pred_bb->index]);
+ if (change
+ && bitmap_bit_p (visited, pred_bb->index))
{
bitmap_clear_bit (visited, pred_bb->index);
*(live->stack_top)++ = pred_bb->index;
@@ -1074,23 +1096,21 @@ live_worklist (tree_live_info_p live)
unsigned b;
basic_block bb;
sbitmap visited = sbitmap_alloc (last_basic_block_for_fn (cfun) + 1);
- bitmap tmp = BITMAP_ALLOC (&liveness_bitmap_obstack);
bitmap_clear (visited);
/* Visit all the blocks in reverse order and propagate live on entry values
into the predecessors blocks. */
FOR_EACH_BB_REVERSE_FN (bb, cfun)
- loe_visit_block (live, bb, visited, tmp);
+ loe_visit_block (live, bb, visited);
/* Process any blocks which require further iteration. */
while (live->stack_top != live->work_stack)
{
b = *--(live->stack_top);
- loe_visit_block (live, BASIC_BLOCK_FOR_FN (cfun, b), visited, tmp);
+ loe_visit_block (live, BASIC_BLOCK_FOR_FN (cfun, b), visited);
}
- BITMAP_FREE (tmp);
sbitmap_free (visited);
}
@@ -1175,7 +1195,7 @@ set_var_live_on_entry (tree ssa_name, tr
/* Calculate the live on exit vectors based on the entry info in LIVEINFO. */
-void
+static void
calculate_live_on_exit (tree_live_info_p liveinfo)
{
basic_block bb;
@@ -1232,7 +1252,6 @@ calculate_live_ranges (var_map map)
unsigned i;
tree_live_info_p live;
- bitmap_obstack_initialize (&liveness_bitmap_obstack);
live = new_tree_live_info (map);
for (i = 0; i < num_var_partitions (map); i++)
{
Index: gcc/tree-ssa-live.h
===================================================================
--- gcc/tree-ssa-live.h (revision 221205)
+++ gcc/tree-ssa-live.h (working copy)
@@ -242,6 +242,10 @@ typedef struct tree_live_info_d
/* Top of workstack. */
int *stack_top;
+
+ /* Obstacks to allocate the bitmaps on. */
+ bitmap_obstack livein_obstack;
+ bitmap_obstack liveout_obstack;
} *tree_live_info_p;
@@ -249,7 +253,8 @@ typedef struct tree_live_info_d
#define LIVEDUMP_EXIT 0x02
#define LIVEDUMP_ALL (LIVEDUMP_ENTRY | LIVEDUMP_EXIT)
extern void delete_tree_live_info (tree_live_info_p);
-extern void calculate_live_on_exit (tree_live_info_p);
+extern void delete_tree_live_info_livein (tree_live_info_p);
+extern void delete_tree_live_info_liveout (tree_live_info_p);
extern tree_live_info_p calculate_live_ranges (var_map);
extern void debug (tree_live_info_d &ref);
extern void debug (tree_live_info_d *ptr);