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-rw-r--r--gcc/ChangeLog21
-rw-r--r--gcc/testsuite/ChangeLog7
-rw-r--r--gcc/testsuite/gcc.dg/tree-ssa/loadpre10.c49
-rw-r--r--gcc/testsuite/gcc.dg/tree-ssa/loadpre11.c14
-rw-r--r--gcc/testsuite/gcc.dg/tree-ssa/loadpre4.c4
-rw-r--r--gcc/testsuite/gcc.dg/tree-ssa/loadpre6.c4
-rw-r--r--gcc/tree-ssa-pre.c229
7 files changed, 296 insertions, 32 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 262b950..4dc5389 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,24 @@
+2006-02-06 Daniel Berlin <dberlin@dberlin.org>
+
+ * tree-ssa-pre.c (bb_value_sets_t): Add antic_safe_loads.
+ (ANTIC_SAFE_LOADS): New macro.
+ (find_or_generate_expression): Add prototype.
+ (set_contains_value): Allow null set for sake of not always having
+ to allocate ANTIC_SAFE_LOADS.
+ (phi_translate): Move placement of AGGREGATE_TYPE_P check.
+ Allow COMPONENT_REF too.
+ (valid_in_set): Allow COMPONENT_REF.
+ Check ANTIC_SAFE_LOADS too.
+ (compute_antic_aux): Print out ANTIC_SAFE_LOADS.
+ (compute_rvuse_and_antic_safe): Add ANTIC_SAFE computation, and
+ rename.
+ (can_PRE_operation): Add COMPONENT_REF.
+ (create_component_ref_by_pieces): New function.
+ (create_expression_by_pieces): Use create_component_ref_by_pieces.
+ (insert_aux): Move AGGREGATE_TYPE_P check here.
+ (compute_avail): Set bb local stmt uids.
+ (pass_pre): Use TODO_update_ssa_only_virtuals.
+
2006-02-06 Ben Elliston <bje@au.ibm.com>
* configure.ac: Unconditionally disable decimal float by default.
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 34202b7..624e598 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+2006-02-06 Daniel Berlin <dberlin@dberlin.org>
+
+ * gcc.dg/tree-ssa/loadpre10.c: New test.
+ * gcc.dg/tree-ssa/loadpre11.c: Ditto.
+ * gcc.dg/tree-ssa/loadpre6.c: Expect one more elimination.
+ * gcc.dg/tree-ssa/loadpre4.c: This should pass now.
+
2006-02-06 Francois-Xavier Coudert <coudert@clipper.ens.fr>
PR libfortran/24685
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loadpre10.c b/gcc/testsuite/gcc.dg/tree-ssa/loadpre10.c
new file mode 100644
index 0000000..4147a70
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/loadpre10.c
@@ -0,0 +1,49 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-pre-stats" } */
+struct tree_common
+{
+ int code;
+};
+union tree_node
+{
+ struct tree_common common;
+};
+typedef union tree_node *tree;
+
+extern tree test (tree, int, int);
+extern tree foo (void);
+extern void abort (void) __attribute__ ((__noreturn__));
+
+/* Redundant loads of expr->common.code */
+tree
+test (tree expr, int t, int D17630)
+{
+ int __i;
+
+L0:
+ if (expr->common.code != 142) goto L23; else goto L2;
+
+L2:
+ __i = 0;
+ goto L10;
+
+L10:
+ __i = __i + 1;
+ if (D17630 != __i) goto L8; else goto L19;
+
+L8:
+ if (t) goto L15; else goto L10;
+
+L15:
+ expr = foo ();
+ if (expr->common.code != 142) goto L23; else goto L0;
+
+L19:
+ abort ();
+
+L23:
+ return expr;
+}
+/* { dg-final { scan-tree-dump-times "Eliminated: 1" 1 "pre"} } */
+/* { dg-final { cleanup-tree-dump "pre" } } */
+
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loadpre11.c b/gcc/testsuite/gcc.dg/tree-ssa/loadpre11.c
new file mode 100644
index 0000000..2980ac0
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/loadpre11.c
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-pre-stats" } */
+int *t;
+int g(int);
+int f(int tt)
+{
+ int *t1 = t;
+ if (*t1)
+ *t1 = 2;
+ return g(*t1);
+}
+/* { dg-final { scan-tree-dump-times "Eliminated: 1" 1 "pre"} } */
+/* { dg-final { cleanup-tree-dump "pre" } } */
+
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loadpre4.c b/gcc/testsuite/gcc.dg/tree-ssa/loadpre4.c
index 3b88615..1e26603 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/loadpre4.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/loadpre4.c
@@ -7,8 +7,6 @@ int main(int *a, int argc)
int i;
int d, e;
- /* With smarter load PRE, we'd be able to recompute the value at the
- kill point. arguably not worth it. */
for (i = 0; i < argc; i++)
{
e = *a;
@@ -17,5 +15,5 @@ int main(int *a, int argc)
return d + e;
}
-/* { dg-final { scan-tree-dump-times "Eliminated: 1" 1 "pre" { xfail *-*-* } } } */
+/* { dg-final { scan-tree-dump-times "Eliminated: 1" 1 "pre" } } */
/* { dg-final { cleanup-tree-dump "pre" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loadpre6.c b/gcc/testsuite/gcc.dg/tree-ssa/loadpre6.c
index a165f01..28a71a8 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/loadpre6.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/loadpre6.c
@@ -30,6 +30,8 @@ foo (void)
abort ();
}
+/* There are some reloaded loads of *cell, and cell->common.chain on various
+ branches. */
void __attribute__((noinline))
remove_useless_vars (tree *unexpanded_var_list, int dump_file)
{
@@ -69,6 +71,6 @@ main (void)
remove_useless_vars (&unexpanded_var_list, 0);
return 0;
}
-/* { dg-final { scan-tree-dump-times "Eliminated: 1" 1 "pre" } } */
+/* { dg-final { scan-tree-dump-times "Eliminated: 2" 1 "pre" } } */
/* { dg-final { cleanup-tree-dump "pre" } } */
diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c
index 4c4cec5..0df5a19 100644
--- a/gcc/tree-ssa-pre.c
+++ b/gcc/tree-ssa-pre.c
@@ -53,6 +53,11 @@ Boston, MA 02110-1301, USA. */
we can repair later on.
3. We can do back-substitution or smarter value numbering to catch
commutative expressions split up over multiple statements.
+ 4. ANTIC_SAFE_LOADS could be a lot smarter than it is now.
+ Right now, it is simply calculating loads that occur before
+ any store in a block, instead of loads that occur before
+ stores that affect them. This is relatively more expensive, and
+ it's not clear how much more it will buy us.
*/
/* For ease of terminology, "expression node" in the below refers to
@@ -258,6 +263,11 @@ typedef struct bb_value_sets
bitmap rvuse_out;
bitmap rvuse_gen;
bitmap rvuse_kill;
+
+ /* For actually occuring loads, as long as they occur before all the
+ other stores in the block, we know they are antic at the top of
+ the block, regardless of RVUSE_KILL. */
+ value_set_t antic_safe_loads;
} *bb_value_sets_t;
#define EXP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->exp_gen
@@ -270,6 +280,7 @@ typedef struct bb_value_sets
#define RVUSE_KILL(BB) ((bb_value_sets_t) ((BB)->aux))->rvuse_kill
#define RVUSE_OUT(BB) ((bb_value_sets_t) ((BB)->aux))->rvuse_out
#define NEW_SETS(BB) ((bb_value_sets_t) ((BB)->aux))->new_sets
+#define ANTIC_SAFE_LOADS(BB) ((bb_value_sets_t) ((BB)->aux))->antic_safe_loads
/* This structure is used to keep track of statistics on what
optimization PRE was able to perform. */
@@ -302,6 +313,7 @@ static bitmap_set_t bitmap_set_new (void);
static value_set_t set_new (bool);
static bool is_undefined_value (tree);
static tree create_expression_by_pieces (basic_block, tree, tree);
+static tree find_or_generate_expression (basic_block, tree, tree);
/* We can add and remove elements and entries to and from sets
@@ -701,7 +713,7 @@ set_contains_value (value_set_t set, tree val)
if (is_gimple_min_invariant (val))
return true;
- if (set->length == 0)
+ if (!set || set->length == 0)
return false;
return value_exists_in_set_bitmap (set, val);
@@ -1102,6 +1114,18 @@ phi_translate (tree expr, value_set_t set, basic_block pred,
tree newval;
if (oldval)
{
+ /* This may seem like a weird place for this
+ check, but it's actually the easiest place to
+ do it. We can't do it lower on in the
+ recursion because it's valid for pieces of a
+ component ref to be of AGGREGATE_TYPE, as long
+ as the outermost one is not.
+ To avoid *that* case, we have a check for
+ AGGREGATE_TYPE_P in insert_aux. However, that
+ check will *not* catch this case because here
+ it occurs in the argument list. */
+ if (AGGREGATE_TYPE_P (TREE_TYPE (oldval)))
+ return NULL;
newval = phi_translate (find_leader (set, oldval),
set, pred, phiblock);
if (newval == NULL)
@@ -1160,7 +1184,7 @@ phi_translate (tree expr, value_set_t set, basic_block pred,
VEC (tree, gc) * newvuses = NULL;
if (TREE_CODE (expr) != INDIRECT_REF
- || AGGREGATE_TYPE_P (TREE_TYPE (expr)))
+ && TREE_CODE (expr) != COMPONENT_REF)
return NULL;
newop1 = phi_translate (find_leader (set, oldop1),
@@ -1435,12 +1459,11 @@ vuses_dies_in_block_x (VEC (tree, gc) *vuses, basic_block block)
for (i = 0; VEC_iterate (tree, vuses, i, vuse); i++)
{
- /* Any places where this is too conservative, are places
+ /* Any places where this is too conservative, are places
where we created a new version and shouldn't have. */
if (!bitmap_bit_p (RVUSE_IN (block), SSA_NAME_VERSION (vuse))
- || bitmap_bit_p (RVUSE_KILL (block), SSA_NAME_VERSION
- (vuse)))
+ || bitmap_bit_p (RVUSE_KILL (block), SSA_NAME_VERSION (vuse)))
return true;
}
return false;
@@ -1501,7 +1524,8 @@ valid_in_set (value_set_t set, tree expr, basic_block block)
case tcc_reference:
{
- if (TREE_CODE (expr) == INDIRECT_REF)
+ if (TREE_CODE (expr) == INDIRECT_REF
+ || TREE_CODE (expr) == COMPONENT_REF)
{
tree op0 = TREE_OPERAND (expr, 0);
if (is_gimple_min_invariant (op0)
@@ -1509,8 +1533,12 @@ valid_in_set (value_set_t set, tree expr, basic_block block)
{
bool retval = set_contains_value (set, op0);
if (retval)
- return !vuses_dies_in_block_x (VALUE_HANDLE_VUSES (vh),
+ {
+ return set_contains_value (ANTIC_SAFE_LOADS (block),
+ vh)
+ || !vuses_dies_in_block_x (VALUE_HANDLE_VUSES (vh),
block);
+ }
return false;
}
}
@@ -1649,7 +1677,12 @@ compute_antic_aux (basic_block block, bool block_has_abnormal_pred_edge)
{
if (ANTIC_OUT)
print_value_set (dump_file, ANTIC_OUT, "ANTIC_OUT", block->index);
+
+ if (ANTIC_SAFE_LOADS (block))
+ print_value_set (dump_file, ANTIC_SAFE_LOADS (block),
+ "ANTIC_SAFE_LOADS", block->index);
print_value_set (dump_file, ANTIC_IN (block), "ANTIC_IN", block->index);
+
if (S)
print_value_set (dump_file, S, "S", block->index);
}
@@ -1803,16 +1836,37 @@ compute_vuse_representatives (void)
VEC_free (tree, heap, phis);
}
-/* Compute reaching vuses. This is a small bit of iterative dataflow
- to determine what virtual uses reach what blocks. Because we can't
- generate overlapping virtual uses, and virtual uses *do* actually
- die, this ends up being faster in most cases than continually
- walking the virtual use/def chains to determine whether we are
- inside a block where a given virtual is still available to be
- used. */
+/* Compute reaching vuses and antic safe loads. RVUSE computation is
+ is a small bit of iterative dataflow to determine what virtual uses
+ reach what blocks. Because we can't generate overlapping virtual
+ uses, and virtual uses *do* actually die, this ends up being faster
+ in most cases than continually walking the virtual use/def chains
+ to determine whether we are inside a block where a given virtual is
+ still available to be used.
+
+ ANTIC_SAFE_LOADS are those loads that actually occur before any kill to
+ their vuses in the block,and thus, are safe at the top of the
+ block.
+
+ An example:
+
+ <block begin>
+ b = *a
+ *a = 9
+ <block end>
+
+ b = *a is an antic safe load because it still safe to consider it
+ ANTIC at the top of the block.
+
+ We currently compute a conservative approximation to
+ ANTIC_SAFE_LOADS. We compute those loads that occur before *any*
+ stores in the block. This is not because it is difficult to
+ compute the precise answer, but because it is expensive. More
+ testing is necessary to determine whether it is worth computing the
+ precise answer. */
static void
-compute_rvuse (void)
+compute_rvuse_and_antic_safe (void)
{
size_t i;
@@ -1820,7 +1874,10 @@ compute_rvuse (void)
basic_block bb;
int *postorder;
bool changed = true;
+ unsigned int *first_store_uid;
+ first_store_uid = xcalloc (n_basic_blocks, sizeof (unsigned int));
+
compute_vuse_representatives ();
FOR_ALL_BB (bb)
@@ -1829,9 +1886,9 @@ compute_rvuse (void)
RVUSE_GEN (bb) = BITMAP_ALLOC (&grand_bitmap_obstack);
RVUSE_KILL (bb) = BITMAP_ALLOC (&grand_bitmap_obstack);
RVUSE_OUT (bb) = BITMAP_ALLOC (&grand_bitmap_obstack);
+ ANTIC_SAFE_LOADS (bb) = NULL;
}
-
/* Mark live on entry */
for (i = 0; i < num_ssa_names; i++)
{
@@ -1854,10 +1911,18 @@ compute_rvuse (void)
def_operand_p defp;
use_operand_p usep;
-
for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
{
tree stmt = bsi_stmt (bsi);
+
+ if (first_store_uid[bb->index] == 0
+ && !ZERO_SSA_OPERANDS (stmt, SSA_OP_VMAYUSE | SSA_OP_VMAYDEF
+ | SSA_OP_VMUSTDEF | SSA_OP_VMUSTKILL))
+ {
+ first_store_uid[bb->index] = stmt_ann (stmt)->uid;
+ }
+
+
FOR_EACH_SSA_USE_OPERAND (usep, stmt, iter, SSA_OP_VIRTUAL_KILLS
| SSA_OP_VMAYUSE)
{
@@ -1950,6 +2015,40 @@ compute_rvuse (void)
dump_bitmap_of_names (dump_file, RVUSE_OUT (bb));
}
}
+
+ FOR_EACH_BB (bb)
+ {
+ value_set_node_t node;
+ if (bitmap_empty_p (RVUSE_KILL (bb)))
+ continue;
+
+ for (node = EXP_GEN (bb)->head; node; node = node->next)
+ {
+ if (REFERENCE_CLASS_P (node->expr))
+ {
+ tree vh = get_value_handle (node->expr);
+ tree maybe = bitmap_find_leader (AVAIL_OUT (bb), vh);
+
+ if (maybe)
+ {
+ tree def = SSA_NAME_DEF_STMT (maybe);
+
+ if (bb_for_stmt (def) != bb)
+ continue;
+
+ if (TREE_CODE (def) == PHI_NODE
+ || stmt_ann (def)->uid < first_store_uid[bb->index])
+ {
+ if (ANTIC_SAFE_LOADS (bb) == NULL)
+ ANTIC_SAFE_LOADS (bb) = set_new (true);
+ value_insert_into_set (ANTIC_SAFE_LOADS (bb),
+ node->expr);
+ }
+ }
+ }
+ }
+ }
+ free (first_store_uid);
}
/* Return true if we can value number the call in STMT. This is true
@@ -1991,6 +2090,7 @@ can_PRE_operation (tree op)
|| BINARY_CLASS_P (op)
|| COMPARISON_CLASS_P (op)
|| TREE_CODE (op) == INDIRECT_REF
+ || TREE_CODE (op) == COMPONENT_REF
|| TREE_CODE (op) == CALL_EXPR;
}
@@ -2005,6 +2105,70 @@ static VEC(tree,heap) *inserted_exprs;
to see which expressions need to be put into GC'able memory */
static VEC(tree, heap) *need_creation;
+/* For COMPONENT_REF's, we can't have any intermediates for the
+ COMPONENT_REF or INDIRECT_REF portion, because we'd end up with
+ trying to rename aggregates into ssa form directly, which is a no
+ no.
+
+ Thus, this routine doesn't create temporaries, it just builds a
+ single access expression for the array, calling
+ find_or_generate_expression to build the innermost pieces.
+
+ This function is a subroutine of create_expression_by_pieces, and
+ should not be called on it's own unless you really know what you
+ are doing.
+*/
+static tree
+create_component_ref_by_pieces (basic_block block, tree expr, tree stmts)
+{
+ tree genop = expr;
+ tree folded;
+
+ if (TREE_CODE (genop) == VALUE_HANDLE)
+ {
+ tree found = bitmap_find_leader (AVAIL_OUT (block), expr);
+ if (found)
+ return found;
+ }
+
+ if (TREE_CODE (genop) == VALUE_HANDLE)
+ genop = VALUE_HANDLE_EXPR_SET (expr)->head->expr;
+
+ switch TREE_CODE (genop)
+ {
+ case COMPONENT_REF:
+ {
+ tree op0;
+ tree op1;
+ op0 = create_component_ref_by_pieces (block,
+ TREE_OPERAND (genop, 0),
+ stmts);
+ op1 = VALUE_HANDLE_EXPR_SET (TREE_OPERAND (genop, 1))->head->expr;
+ folded = fold_build3 (COMPONENT_REF, TREE_TYPE (genop), op0, op1,
+ NULL_TREE);
+ return folded;
+ }
+ break;
+ case INDIRECT_REF:
+ {
+ tree op1 = TREE_OPERAND (genop, 0);
+ tree genop1 = find_or_generate_expression (block, op1, stmts);
+
+ folded = fold_build1 (TREE_CODE (genop), TREE_TYPE (genop),
+ genop1);
+ return folded;
+ }
+ break;
+ case VAR_DECL:
+ case PARM_DECL:
+ case SSA_NAME:
+ return genop;
+ default:
+ gcc_unreachable ();
+ }
+
+ return NULL_TREE;
+}
/* Find a leader for an expression, or generate one using
create_expression_by_pieces if it's ANTIC but
@@ -2093,13 +2257,19 @@ create_expression_by_pieces (basic_block block, tree expr, tree stmts)
}
break;
case tcc_reference:
- gcc_assert (TREE_CODE (expr) == INDIRECT_REF);
{
- tree op1 = TREE_OPERAND (expr, 0);
- tree genop1 = find_or_generate_expression (block, op1, stmts);
-
- folded = fold_build1 (TREE_CODE (expr), TREE_TYPE (expr),
- genop1);
+ if (TREE_CODE (expr) == COMPONENT_REF)
+ {
+ folded = create_component_ref_by_pieces (block, expr, stmts);
+ }
+ else
+ {
+ tree op1 = TREE_OPERAND (expr, 0);
+ tree genop1 = find_or_generate_expression (block, op1, stmts);
+
+ folded = fold_build1 (TREE_CODE (expr), TREE_TYPE (expr),
+ genop1);
+ }
break;
}
@@ -2404,7 +2574,8 @@ insert_aux (basic_block block)
node;
node = node->next)
{
- if (can_PRE_operation (node->expr))
+ if (can_PRE_operation (node->expr)
+ && !AGGREGATE_TYPE_P (TREE_TYPE (node->expr)))
{
tree *avail;
tree val;
@@ -2746,7 +2917,7 @@ insert_extra_phis (basic_block block, basic_block dom)
FOR_EACH_EDGE (e, ei, block->preds)
{
- /* We cannot handle abnormal incomming edges correctly. */
+ /* We cannot handle abnormal incoming edges correctly. */
if (e->flags & EDGE_ABNORMAL)
return;
@@ -3076,7 +3247,6 @@ compute_avail (void)
basic_block *worklist;
size_t sp = 0;
tree param;
-
/* For arguments with default definitions, we pretend they are
defined in the entry block. */
for (param = DECL_ARGUMENTS (current_function_decl);
@@ -3121,6 +3291,7 @@ compute_avail (void)
block_stmt_iterator bsi;
tree stmt, phi;
basic_block dom;
+ unsigned int stmt_uid = 1;
/* Pick a block from the worklist. */
block = worklist[--sp];
@@ -3152,6 +3323,8 @@ compute_avail (void)
stmt = bsi_stmt (bsi);
ann = stmt_ann (stmt);
+
+ ann->uid = stmt_uid++;
/* For regular value numbering, we are only interested in
assignments of the form X_i = EXPR, where EXPR represents
@@ -3597,7 +3770,7 @@ execute_pre (bool do_fre)
if (!do_fre && n_basic_blocks < 4000)
{
vuse_names = XCNEWVEC (bitmap, num_ssa_names);
- compute_rvuse ();
+ compute_rvuse_and_antic_safe ();
compute_antic ();
insert ();
free (vuse_names);
@@ -3655,7 +3828,7 @@ struct tree_opt_pass pass_pre =
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
- TODO_update_ssa | TODO_dump_func | TODO_ggc_collect
+ TODO_update_ssa_only_virtuals | TODO_dump_func | TODO_ggc_collect
| TODO_verify_ssa, /* todo_flags_finish */
0 /* letter */
};
generated by cgit v1.1 at 2025-02-25 15:32:16 +0000