This separates constant and non-constant value-ids to allow for
a more efficient constant_value_id_p and for more efficient bit-packing
inside the bitmap sets which never contain any constant values.
There's further optimization opportunities but at this stage
I'll do small refactorings.
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
2020-11-06 Richard Biener <rguent...@suse.de>
* tree-ssa-sccvn.h (get_max_constant_value_id): Declare.
(get_next_constant_value_id): Likewise.
(value_id_constant_p): Inline and simplify.
* tree-ssa-sccvn.c (constant_value_ids): Remove.
(next_constant_value_id): Add.
(get_or_alloc_constant_value_id): Adjust.
(value_id_constant_p): Remove definition.
(get_max_constant_value_id): Define.
(get_next_value_id): Add assert for overflow.
(get_next_constant_value_id): Define.
(run_rpo_vn): Adjust.
(free_rpo_vn): Likewise.
(do_rpo_vn): Initialize next_constant_value_id.
* tree-ssa-pre.c (constant_value_expressions): New.
(add_to_value): Split into constant/non-constant value
handling. Avoid exact re-allocation.
(vn_valnum_from_value_id): Adjust.
(phi_translate_1): Remove spurious exact re-allocation.
(bitmap_find_leader): Adjust. Make sure we return
a CONSTANT value for a constant value id.
(do_pre_regular_insertion): Use 2 auto-elements for avail.
(do_pre_partial_partial_insertion): Likewise.
(init_pre): Allocate constant_value_expressions.
(fini_pre): Release constant_value_expressions.
---
gcc/tree-ssa-pre.c | 57 ++++++++++++++++++++++++++++----------------
gcc/tree-ssa-sccvn.c | 34 ++++++++++++++++----------
gcc/tree-ssa-sccvn.h | 12 +++++++++-
3 files changed, 69 insertions(+), 34 deletions(-)
diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c
index 39c52c9b0f0..65e8aaaca02 100644
--- a/gcc/tree-ssa-pre.c
+++ b/gcc/tree-ssa-pre.c
@@ -444,6 +444,9 @@ public:
/* Mapping from value id to expressions with that value_id. */
static vec<bitmap> value_expressions;
+/* ??? We want to just record a single expression for each constant
+ value, one of kind CONSTANT. */
+static vec<bitmap> constant_value_expressions;
/* Sets that we need to keep track of. */
typedef struct bb_bitmap_sets
@@ -624,18 +627,30 @@ add_to_value (unsigned int v, pre_expr e)
gcc_checking_assert (get_expr_value_id (e) == v);
- if (v >= value_expressions.length ())
+ if (value_id_constant_p (v))
{
- value_expressions.safe_grow_cleared (v + 1, true);
- }
+ if (-v >= constant_value_expressions.length ())
+ constant_value_expressions.safe_grow_cleared (-v + 1);
- set = value_expressions[v];
- if (!set)
- {
- set = BITMAP_ALLOC (&grand_bitmap_obstack);
- value_expressions[v] = set;
+ set = constant_value_expressions[-v];
+ if (!set)
+ {
+ set = BITMAP_ALLOC (&grand_bitmap_obstack);
+ constant_value_expressions[-v] = set;
+ }
}
+ else
+ {
+ if (v >= value_expressions.length ())
+ value_expressions.safe_grow_cleared (v + 1);
+ set = value_expressions[v];
+ if (!set)
+ {
+ set = BITMAP_ALLOC (&grand_bitmap_obstack);
+ value_expressions[v] = set;
+ }
+ }
bitmap_set_bit (set, get_or_alloc_expression_id (e));
}
@@ -687,7 +702,11 @@ vn_valnum_from_value_id (unsigned int val)
{
bitmap_iterator bi;
unsigned int i;
- bitmap exprset = value_expressions[val];
+ bitmap exprset;
+ if (value_id_constant_p (val))
+ exprset = constant_value_expressions[-val];
+ else
+ exprset = value_expressions[val];
EXECUTE_IF_SET_IN_BITMAP (exprset, 0, i, bi)
{
pre_expr vexpr = expression_for_id (i);
@@ -1451,8 +1470,6 @@ phi_translate_1 (bitmap_set_t dest,
else
{
new_val_id = get_next_value_id ();
- value_expressions.safe_grow_cleared (get_max_value_id () + 1,
- true);
nary = vn_nary_op_insert_pieces (newnary->length,
newnary->opcode,
newnary->type,
@@ -1603,11 +1620,7 @@ phi_translate_1 (bitmap_set_t dest,
else
{
if (changed || !same_valid)
- {
- new_val_id = get_next_value_id ();
- value_expressions.safe_grow_cleared
- (get_max_value_id () + 1, true);
- }
+ new_val_id = get_next_value_id ();
else
new_val_id = ref->value_id;
if (!newoperands.exists ())
@@ -1745,7 +1758,7 @@ bitmap_find_leader (bitmap_set_t set, unsigned int val)
{
unsigned int i;
bitmap_iterator bi;
- bitmap exprset = value_expressions[val];
+ bitmap exprset = constant_value_expressions[-val];
EXECUTE_IF_SET_IN_BITMAP (exprset, 0, i, bi)
{
@@ -1753,6 +1766,7 @@ bitmap_find_leader (bitmap_set_t set, unsigned int val)
if (expr->kind == CONSTANT)
return expr;
}
+ gcc_unreachable ();
}
if (bitmap_set_contains_value (set, val))
{
@@ -3190,7 +3204,7 @@ do_pre_regular_insertion (basic_block block, basic_block
dom)
bool new_stuff = false;
vec<pre_expr> exprs;
pre_expr expr;
- auto_vec<pre_expr> avail;
+ auto_vec<pre_expr, 2> avail;
int i;
exprs = sorted_array_from_bitmap_set (ANTIC_IN (block));
@@ -3357,7 +3371,7 @@ do_pre_partial_partial_insertion (basic_block block,
basic_block dom)
bool new_stuff = false;
vec<pre_expr> exprs;
pre_expr expr;
- auto_vec<pre_expr> avail;
+ auto_vec<pre_expr, 2> avail;
int i;
exprs = sorted_array_from_bitmap_set (PA_IN (block));
@@ -4111,7 +4125,9 @@ init_pre (void)
expressions.create (0);
expressions.safe_push (NULL);
value_expressions.create (get_max_value_id () + 1);
- value_expressions.safe_grow_cleared (get_max_value_id () + 1, true);
+ value_expressions.quick_grow_cleared (get_max_value_id () + 1);
+ constant_value_expressions.create (get_max_constant_value_id () + 1);
+ constant_value_expressions.quick_grow_cleared (get_max_constant_value_id ()
+ 1);
name_to_id.create (0);
inserted_exprs = BITMAP_ALLOC (NULL);
@@ -4142,6 +4158,7 @@ static void
fini_pre ()
{
value_expressions.release ();
+ constant_value_expressions.release ();
expressions.release ();
BITMAP_FREE (inserted_exprs);
bitmap_obstack_release (&grand_bitmap_obstack);
diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c
index 188ed4e713c..54b928629d9 100644
--- a/gcc/tree-ssa-sccvn.c
+++ b/gcc/tree-ssa-sccvn.c
@@ -288,7 +288,6 @@ vn_constant_hasher::equal (const vn_constant_s *vc1, const
vn_constant_s *vc2)
}
static hash_table<vn_constant_hasher> *constant_to_value_id;
-static bitmap constant_value_ids;
/* Obstack we allocate the vn-tables elements from. */
@@ -322,6 +321,7 @@ tree VN_TOP;
/* Unique counter for our value ids. */
static unsigned int next_value_id;
+static int next_constant_value_id;
/* Table of vn_ssa_aux_t's, one per ssa_name. The vn_ssa_aux_t objects
@@ -611,20 +611,11 @@ get_or_alloc_constant_value_id (tree constant)
vcp = XNEW (struct vn_constant_s);
vcp->hashcode = vc.hashcode;
vcp->constant = constant;
- vcp->value_id = get_next_value_id ();
+ vcp->value_id = get_next_constant_value_id ();
*slot = vcp;
- bitmap_set_bit (constant_value_ids, vcp->value_id);
return vcp->value_id;
}
-/* Return true if V is a value id for a constant. */
-
-bool
-value_id_constant_p (unsigned int v)
-{
- return bitmap_bit_p (constant_value_ids, v);
-}
-
/* Compute the hash for a reference operand VRO1. */
static void
@@ -5594,14 +5585,32 @@ get_max_value_id (void)
return next_value_id;
}
+/* Return the maximum constant value id we have ever seen. */
+
+unsigned int
+get_max_constant_value_id (void)
+{
+ return -next_constant_value_id;
+}
+
/* Return the next unique value id. */
unsigned int
get_next_value_id (void)
{
+ gcc_checking_assert ((int)next_value_id > 0);
return next_value_id++;
}
+/* Return the next unique value id for constants. */
+
+unsigned int
+get_next_constant_value_id (void)
+{
+ gcc_checking_assert (next_constant_value_id < 0);
+ return next_constant_value_id--;
+}
+
/* Compare two expressions E1 and E2 and return true if they are equal. */
@@ -6672,7 +6681,6 @@ run_rpo_vn (vn_lookup_kind kind)
/* ??? Prune requirement of these. */
constant_to_value_id = new hash_table<vn_constant_hasher> (23);
- constant_value_ids = BITMAP_ALLOC (NULL);
/* Initialize the value ids and prune out remaining VN_TOPs
from dead code. */
@@ -6739,7 +6747,6 @@ free_rpo_vn (void)
delete constant_to_value_id;
constant_to_value_id = NULL;
- BITMAP_FREE (constant_value_ids);
}
/* Hook for maybe_push_res_to_seq, lookup the expression in the VN tables. */
@@ -7469,6 +7476,7 @@ do_rpo_vn (function *fn, edge entry, bitmap exit_bbs,
/ (n_basic_blocks_for_fn (fn) - NUM_FIXED_BLOCKS));
VN_TOP = create_tmp_var_raw (void_type_node, "vn_top");
next_value_id = 1;
+ next_constant_value_id = -1;
vn_ssa_aux_hash = new hash_table <vn_ssa_aux_hasher> (region_size * 2);
gcc_obstack_init (&vn_ssa_aux_obstack);
diff --git a/gcc/tree-ssa-sccvn.h b/gcc/tree-ssa-sccvn.h
index 48701c32544..3420e6bca09 100644
--- a/gcc/tree-ssa-sccvn.h
+++ b/gcc/tree-ssa-sccvn.h
@@ -269,11 +269,21 @@ bool vn_nary_op_eq (const_vn_nary_op_t const vno1,
bool vn_nary_may_trap (vn_nary_op_t);
bool vn_reference_may_trap (vn_reference_t);
bool vn_reference_eq (const_vn_reference_t const, const_vn_reference_t const);
+
unsigned int get_max_value_id (void);
+unsigned int get_max_constant_value_id (void);
unsigned int get_next_value_id (void);
+unsigned int get_next_constant_value_id (void);
unsigned int get_constant_value_id (tree);
unsigned int get_or_alloc_constant_value_id (tree);
-bool value_id_constant_p (unsigned int);
+
+/* Return true if V is a value id for a constant. */
+static inline bool
+value_id_constant_p (unsigned int v)
+{
+ return (int)v < 0;
+}
+
tree fully_constant_vn_reference_p (vn_reference_t);
tree vn_nary_simplify (vn_nary_op_t);
--
2.26.2
