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re PR tree-optimization/34043 (Missed optimization causing extra loads and stores when using x86_64 builtin function together with aggregate types.)

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2008-03-14  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/34043
	PR tree-optimization/33989
	* tree-ssa-pre.c (execute_pre): Allow SCCVN to do insertion
	when doing FRE.
	(bitmap_find_leader): Use extra argument to verify dominance
	relationship inside a basic-block.
	(can_PRE_operation): Add VIEW_CONVERT_EXPR.
	(find_leader_in_sets): Adjust.
	(create_component_ref_by_pieces): Take extra argument for
	dominance check, handle lookup failures.
	(find_or_generate_expression): Likewise.
	(create_expression_by_pieces): Likewise.
	(insert_into_preds_of_block): Adjust.
	(create_value_expr_from): If asked for, verify all operands
	are in the blocks AVAIL_OUT set.
	(make_values_for_stmt): Check for SSA_NAMEs that are life
	over an abnormal edge.
	(compute_avail): Remove such check.
	(do_SCCVN_insertion): New function.
	(eliminate): If we do not find a leader suitable for replacement
	insert a replacement expression from SCCVN if available.
	* tree-ssa-sccvn.h (run_scc_vn): Update prototype.
	(struct vn_ssa_aux): Add needs_insertion flag.
	* tree-ssa-sccvn.c (may_insert): New global flag.
	(copy_reference_ops_from_ref): Value-number union member access
	based on its size, not type and member if insertion is allowed.
	(visit_reference_op_load): For a weak match from union type
	punning lookup a view-converted value and insert a SSA_NAME
	for that value if that is not found.
	(visit_use): Make dumps shorter.  Do not disallow value numbering
	SSA_NAMEs that are life over an abnormal edge to constants.
	(free_scc_vn): Release inserted SSA_NAMEs.
	(run_scc_vn): New flag to specify whether insertion is allowed.
	Process SSA_NAMEs in forward order.
	* tree-ssa-loop-im.c (for_each_index): Handle invariant
	ADDR_EXPRs inside VIEW_CONVERT_EXPR.
	* fold-const.c (fold_unary): Fold VIEW_CONVERT_EXPRs from/to
	pointer type to/from integral types that do not change the
	precision to regular conversions.

	* gcc.dg/tree-ssa/ssa-fre-7.c: New testcase.
	* gcc.dg/tree-ssa/ssa-fre-8.c: Likewise.
	* gcc.dg/tree-ssa/ssa-fre-9.c: Likewise.
	* gcc.dg/tree-ssa/ssa-fre-10.c: Likewise.
	* gcc.dg/tree-ssa/ssa-pre-17.c: Likewise.

From-SVN: r133218
This commit is contained in:
Richard Guenther 2008-03-14 14:52:07 +00:00 • committed by Richard Biener
parent c539732f96
commit 3d45dd59c7
12 changed files with 442 additions and 60 deletions
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42
gcc/ChangeLog
View file

@ -1,3 +1,45 @@
2008-03-14 Richard Guenther <rguenther@suse.de>
PR tree-optimization/34043
PR tree-optimization/33989
* tree-ssa-pre.c (execute_pre): Allow SCCVN to do insertion
when doing FRE.
(bitmap_find_leader): Use extra argument to verify dominance
relationship inside a basic-block.
(can_PRE_operation): Add VIEW_CONVERT_EXPR.
(find_leader_in_sets): Adjust.
(create_component_ref_by_pieces): Take extra argument for
dominance check, handle lookup failures.
(find_or_generate_expression): Likewise.
(create_expression_by_pieces): Likewise.
(insert_into_preds_of_block): Adjust.
(create_value_expr_from): If asked for, verify all operands
are in the blocks AVAIL_OUT set.
(make_values_for_stmt): Check for SSA_NAMEs that are life
over an abnormal edge.
(compute_avail): Remove such check.
(do_SCCVN_insertion): New function.
(eliminate): If we do not find a leader suitable for replacement
insert a replacement expression from SCCVN if available.
* tree-ssa-sccvn.h (run_scc_vn): Update prototype.
(struct vn_ssa_aux): Add needs_insertion flag.
* tree-ssa-sccvn.c (may_insert): New global flag.
(copy_reference_ops_from_ref): Value-number union member access
based on its size, not type and member if insertion is allowed.
(visit_reference_op_load): For a weak match from union type
punning lookup a view-converted value and insert a SSA_NAME
for that value if that is not found.
(visit_use): Make dumps shorter. Do not disallow value numbering
SSA_NAMEs that are life over an abnormal edge to constants.
(free_scc_vn): Release inserted SSA_NAMEs.
(run_scc_vn): New flag to specify whether insertion is allowed.
Process SSA_NAMEs in forward order.
* tree-ssa-loop-im.c (for_each_index): Handle invariant
ADDR_EXPRs inside VIEW_CONVERT_EXPR.
* fold-const.c (fold_unary): Fold VIEW_CONVERT_EXPRs from/to
pointer type to/from integral types that do not change the
precision to regular conversions.
2008-03-13 Uros Bizjak <ubizjak@gmail.com>
* doc/extend.texi (X86 Built-in Functions) [__builtin_ia32_psll?,

21
gcc/fold-const.c
View file

@ -7961,19 +7961,24 @@ fold_unary (enum tree_code code, tree type, tree op0)
/* For integral conversions with the same precision or pointer
conversions use a NOP_EXPR instead. */
if ((INTEGRAL_TYPE_P (type) && INTEGRAL_TYPE_P (TREE_TYPE (op0))
&& TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0))
/* Do not muck with VIEW_CONVERT_EXPRs that convert from
a sub-type to its base type as generated by the Ada FE. */
&& !TREE_TYPE (TREE_TYPE (op0)))
|| (POINTER_TYPE_P (type) && POINTER_TYPE_P (TREE_TYPE (op0))))
if ((INTEGRAL_TYPE_P (type)
|| POINTER_TYPE_P (type))
&& (INTEGRAL_TYPE_P (TREE_TYPE (op0))
|| POINTER_TYPE_P (TREE_TYPE (op0)))
&& TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0))
/* Do not muck with VIEW_CONVERT_EXPRs that convert from
a sub-type to its base type as generated by the Ada FE. */
&& !(INTEGRAL_TYPE_P (TREE_TYPE (op0))
&& TREE_TYPE (TREE_TYPE (op0))))
return fold_convert (type, op0);
/* Strip inner integral conversions that do not change the precision. */
if ((TREE_CODE (op0) == NOP_EXPR
|| TREE_CODE (op0) == CONVERT_EXPR)
&& INTEGRAL_TYPE_P (TREE_TYPE (op0))
&& INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0)))
&& (INTEGRAL_TYPE_P (TREE_TYPE (op0))
|| POINTER_TYPE_P (TREE_TYPE (op0)))
&& (INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0)))
|| POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0))))
&& (TYPE_PRECISION (TREE_TYPE (op0))
== TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0)))))
return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));

10
gcc/testsuite/ChangeLog
View file

@ -1,3 +1,13 @@
2008-03-14 Richard Guenther <rguenther@suse.de>
PR tree-optimization/34043
PR tree-optimization/33989
* gcc.dg/tree-ssa/ssa-fre-7.c: New testcase.
* gcc.dg/tree-ssa/ssa-fre-8.c: Likewise.
* gcc.dg/tree-ssa/ssa-fre-9.c: Likewise.
* gcc.dg/tree-ssa/ssa-fre-10.c: Likewise.
* gcc.dg/tree-ssa/ssa-pre-17.c: Likewise.
2008-03-14 H.J. Lu <hongjiu.lu@intel.com>
Uros Bizjak <ubizjak@gmail.com>

20
gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-10.c Normal file
View file

@ -0,0 +1,20 @@
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-pre-stats" } */
union loc { unsigned reg; signed offset; };
void __frame_state_for (volatile char *state_in, int x)
{
union loc fs;
int reg;
for (;;) {
switch (x) {
case 0:
*state_in = fs.reg;
case 1:
*state_in = fs.offset;
}
}
}
/* { dg-final { scan-tree-dump "Insertions: 0" "pre" } } */
/* { dg-final { cleanup-tree-dump "pre" } } */

31
gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-7.c Normal file
View file

@ -0,0 +1,31 @@
/* { dg-do compile } */
/* { dg-options "-O -fdump-tree-fre-details -fdump-tree-optimized" } */
struct X {
int i;
union {
int j;
int k;
float f;
} u;
};
int foo(int j)
{
struct X a;
a.u.j = j;
a.u.f = a.u.f;
a.u.f = a.u.f;
a.u.j = a.u.j;
a.u.f = a.u.f;
return a.u.k;
}
/* { dg-final { scan-tree-dump-times "Inserted pretmp" 1 "fre" } } */
/* { dg-final { scan-tree-dump-times "Replaced a.u.f with pretmp" 3 "fre" } } */
/* { dg-final { scan-tree-dump-times "Replaced a.u.k with j" 1 "fre" } } */
/* { dg-final { scan-tree-dump "= VIEW_CONVERT_EXPR<float>\\\(j_" "fre" } } */
/* { dg-final { scan-tree-dump "return j" "optimized" } } */
/* { dg-final { cleanup-tree-dump "fre" } } */
/* { dg-final { cleanup-tree-dump "optimized" } } */

27
gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-8.c Normal file
View file

@ -0,0 +1,27 @@
/* { dg-do compile } */
/* { dg-options "-O -fdump-tree-fre-details" } */
union U {
int i;
float f;
};
int foo(int i, int b)
{
union U u;
if (b)
{
i = i << 2;
u.i = i;
return u.f;
}
else
{
i = i << 2;
u.i = i;
return u.f;
}
}
/* { dg-final { scan-tree-dump-times "Replaced u.f with pretmp" 2 "fre" } } */
/* { dg-final { scan-tree-dump-times "Inserted pretmp" 2 "fre" } } */
/* { dg-final { cleanup-tree-dump "fre" } } */

28
gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-9.c Normal file
View file

@ -0,0 +1,28 @@
/* { dg-do compile } */
/* { dg-options "-O -fdump-tree-fre-stats" } */
union loc {
unsigned reg;
signed offset;
};
void __frame_state_for2 (volatile char *state_in)
{
union loc fs;
{
*state_in = fs.reg;
*state_in = fs.offset;
}
}
void __frame_state_for1 (volatile char *state_in)
{
union loc fs;
for (;;)
{
*state_in = fs.offset;
*state_in = fs.reg;
}
}
/* { dg-final { scan-tree-dump-times "Eliminated: 1" 2 "fre" } } */
/* { dg-final { scan-tree-dump-times "Insertions: 1" 2 "fre" } } */
/* { dg-final { cleanup-tree-dump "fre" } } */

18
gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-17.c Normal file
View file

@ -0,0 +1,18 @@
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-pre-stats" } */
typedef union {
int i;
float f;
} U;
int foo(U *u, int b, int i)
{
u->i = 0;
if (b)
u->i = i;
return u->i;
}
/* { dg-final { scan-tree-dump "Eliminated: 1" "pre" } } */
/* { dg-final { cleanup-tree-dump "pre" } } */

4
gcc/tree-ssa-loop-im.c
View file

@ -208,6 +208,10 @@ for_each_index (tree *addr_p, bool (*cbck) (tree, tree *, void *), void *data)
case CONSTRUCTOR:
return true;
case ADDR_EXPR:
gcc_assert (is_gimple_min_invariant (*addr_p));
return true;
case TARGET_MEM_REF:
idx = &TMR_BASE (*addr_p);
if (*idx

196
gcc/tree-ssa-pre.c
View file

@ -376,15 +376,15 @@ static struct
} pre_stats;
static bool do_partial_partial;
static tree bitmap_find_leader (bitmap_set_t, tree);
static tree bitmap_find_leader (bitmap_set_t, tree, tree);
static void bitmap_value_insert_into_set (bitmap_set_t, tree);
static void bitmap_value_replace_in_set (bitmap_set_t, tree);
static void bitmap_set_copy (bitmap_set_t, bitmap_set_t);
static bool bitmap_set_contains_value (bitmap_set_t, tree);
static void bitmap_insert_into_set (bitmap_set_t, tree);
static bitmap_set_t bitmap_set_new (void);
static tree create_expression_by_pieces (basic_block, tree, tree);
static tree find_or_generate_expression (basic_block, tree, tree);
static tree create_expression_by_pieces (basic_block, tree, tree, tree);
static tree find_or_generate_expression (basic_block, tree, tree, tree);
/* We can add and remove elements and entries to and from sets
and hash tables, so we use alloc pools for them. */
@ -954,9 +954,9 @@ find_leader_in_sets (tree expr, bitmap_set_t set1, bitmap_set_t set2)
{
tree result;
result = bitmap_find_leader (set1, expr);
result = bitmap_find_leader (set1, expr, NULL_TREE);
if (!result && set2)
result = bitmap_find_leader (set2, expr);
result = bitmap_find_leader (set2, expr, NULL_TREE);
return result;
}
@ -1394,11 +1394,12 @@ phi_translate_set (bitmap_set_t dest, bitmap_set_t set, basic_block pred,
}
/* Find the leader for a value (i.e., the name representing that
value) in a given set, and return it. Return NULL if no leader is
found. */
value) in a given set, and return it. If STMT is non-NULL it
makes sure the defining statement for the leader dominates it.
Return NULL if no leader is found. */
static tree
bitmap_find_leader (bitmap_set_t set, tree val)
bitmap_find_leader (bitmap_set_t set, tree val, tree stmt)
{
if (val == NULL)
return NULL;
@ -1425,7 +1426,17 @@ bitmap_find_leader (bitmap_set_t set, tree val)
EXECUTE_IF_AND_IN_BITMAP (exprset->expressions,
set->expressions, 0, i, bi)
return expression_for_id (i);
{
tree val = expression_for_id (i);
if (stmt)
{
tree def_stmt = SSA_NAME_DEF_STMT (val);
if (bb_for_stmt (def_stmt) == bb_for_stmt (stmt)
&& stmt_ann (def_stmt)->uid >= stmt_ann (stmt)->uid)
continue;
}
return val;
}
}
return NULL;
}
@ -2107,6 +2118,7 @@ can_PRE_operation (tree op)
|| COMPARISON_CLASS_P (op)
|| TREE_CODE (op) == INDIRECT_REF
|| TREE_CODE (op) == COMPONENT_REF
|| TREE_CODE (op) == VIEW_CONVERT_EXPR
|| TREE_CODE (op) == CALL_EXPR
|| TREE_CODE (op) == ARRAY_REF;
}
@ -2136,14 +2148,15 @@ static VEC(tree, heap) *need_creation;
are doing.
*/
static tree
create_component_ref_by_pieces (basic_block block, tree expr, tree stmts)
create_component_ref_by_pieces (basic_block block, tree expr, tree stmts,
tree domstmt)
{
tree genop = expr;
tree folded;
if (TREE_CODE (genop) == VALUE_HANDLE)
{
tree found = bitmap_find_leader (AVAIL_OUT (block), expr);
tree found = bitmap_find_leader (AVAIL_OUT (block), expr, domstmt);
if (found)
return found;
}
@ -2163,16 +2176,18 @@ create_component_ref_by_pieces (basic_block block, tree expr, tree stmts)
tree op1, op2, op3;
op0 = create_component_ref_by_pieces (block,
TREE_OPERAND (genop, 0),
stmts);
stmts, domstmt);
op1 = TREE_OPERAND (genop, 1);
if (TREE_CODE (op1) == VALUE_HANDLE)
op1 = find_or_generate_expression (block, op1, stmts);
op1 = find_or_generate_expression (block, op1, stmts, domstmt);
op2 = TREE_OPERAND (genop, 2);
if (op2 && TREE_CODE (op2) == VALUE_HANDLE)
op2 = find_or_generate_expression (block, op2, stmts);
op2 = find_or_generate_expression (block, op2, stmts, domstmt);
op3 = TREE_OPERAND (genop, 3);
if (op3 && TREE_CODE (op3) == VALUE_HANDLE)
op3 = find_or_generate_expression (block, op3, stmts);
op3 = find_or_generate_expression (block, op3, stmts, domstmt);
if (!op0 || !op1)
return NULL_TREE;
folded = build4 (ARRAY_REF, TREE_TYPE (genop), op0, op1,
op2, op3);
return folded;
@ -2183,7 +2198,9 @@ create_component_ref_by_pieces (basic_block block, tree expr, tree stmts)
tree op1;
op0 = create_component_ref_by_pieces (block,
TREE_OPERAND (genop, 0),
stmts);
stmts, domstmt);
if (!op0)
return NULL_TREE;
/* op1 should be a FIELD_DECL, which are represented by
themselves. */
op1 = TREE_OPERAND (genop, 1);
@ -2195,7 +2212,9 @@ create_component_ref_by_pieces (basic_block block, tree expr, tree stmts)
case INDIRECT_REF:
{
tree op1 = TREE_OPERAND (genop, 0);
tree genop1 = find_or_generate_expression (block, op1, stmts);
tree genop1 = find_or_generate_expression (block, op1, stmts, domstmt);
if (!genop1)
return NULL_TREE;
folded = fold_build1 (TREE_CODE (genop), TREE_TYPE (genop),
genop1);
@ -2222,12 +2241,17 @@ create_component_ref_by_pieces (basic_block block, tree expr, tree stmts)
EXPR is the expression to find a leader or generate for.
STMTS is the statement list to put the inserted expressions on.
Returns the SSA_NAME of the LHS of the generated expression or the
leader. */
leader.
DOMSTMT if non-NULL is a statement that should be dominated by
all uses in the generated expression. If DOMSTMT is non-NULL this
routine can fail and return NULL_TREE. Otherwise it will assert
on failure. */
static tree
find_or_generate_expression (basic_block block, tree expr, tree stmts)
find_or_generate_expression (basic_block block, tree expr, tree stmts,
tree domstmt)
{
tree genop = bitmap_find_leader (AVAIL_OUT (block), expr);
tree genop = bitmap_find_leader (AVAIL_OUT (block), expr, domstmt);
/* If it's still NULL, it must be a complex expression, so generate
it recursively. */
@ -2247,10 +2271,14 @@ find_or_generate_expression (basic_block block, tree expr, tree stmts)
if (can_PRE_operation (genop))
{
handled = true;
genop = create_expression_by_pieces (block, genop, stmts);
genop = create_expression_by_pieces (block, genop, stmts,
domstmt);
break;
}
}
if (!handled && domstmt)
return NULL_TREE;
gcc_assert (handled);
}
return genop;
@ -2269,10 +2297,15 @@ find_or_generate_expression (basic_block block, tree expr, tree stmts)
partially or fully redundant. Those that are will be either made
fully redundant during the next iteration of insert (for partially
redundant ones), or eliminated by eliminate (for fully redundant
ones). */
ones).
If DOMSTMT is non-NULL then we make sure that all uses in the
expressions dominate that statement. In this case the function
can return NULL_TREE to signal failure. */
static tree
create_expression_by_pieces (basic_block block, tree expr, tree stmts)
create_expression_by_pieces (basic_block block, tree expr, tree stmts,
tree domstmt)
{
tree temp, name;
tree folded, forced_stmts, newexpr;
@ -2293,7 +2326,9 @@ create_expression_by_pieces (basic_block block, tree expr, tree stmts)
fn = CALL_EXPR_FN (expr);
sc = CALL_EXPR_STATIC_CHAIN (expr);
genfn = find_or_generate_expression (block, fn, stmts);
genfn = find_or_generate_expression (block, fn, stmts, domstmt);
if (!genfn)
return NULL_TREE;
nargs = call_expr_nargs (expr);
buffer = (tree*) alloca (nargs * sizeof (tree));
@ -2301,13 +2336,20 @@ create_expression_by_pieces (basic_block block, tree expr, tree stmts)
for (i = 0; i < nargs; i++)
{
tree arg = CALL_EXPR_ARG (expr, i);
buffer[i] = find_or_generate_expression (block, arg, stmts);
buffer[i] = find_or_generate_expression (block, arg, stmts,
domstmt);
if (!buffer[i])
return NULL_TREE;
}
folded = build_call_array (TREE_TYPE (expr), genfn, nargs, buffer);
if (sc)
CALL_EXPR_STATIC_CHAIN (folded) =
find_or_generate_expression (block, sc, stmts);
{
CALL_EXPR_STATIC_CHAIN (folded) =
find_or_generate_expression (block, sc, stmts, domstmt);
if (!CALL_EXPR_STATIC_CHAIN (folded))
return NULL_TREE;
}
folded = fold (folded);
break;
}
@ -2317,12 +2359,18 @@ create_expression_by_pieces (basic_block block, tree expr, tree stmts)
if (TREE_CODE (expr) == COMPONENT_REF
|| TREE_CODE (expr) == ARRAY_REF)
{
folded = create_component_ref_by_pieces (block, expr, stmts);
folded = create_component_ref_by_pieces (block, expr, stmts,
domstmt);
if (!folded)
return NULL_TREE;
}
else
{
tree op1 = TREE_OPERAND (expr, 0);
tree genop1 = find_or_generate_expression (block, op1, stmts);
tree genop1 = find_or_generate_expression (block, op1, stmts,
domstmt);
if (!genop1)
return NULL_TREE;
folded = fold_build1 (TREE_CODE (expr), TREE_TYPE (expr),
genop1);
@ -2335,8 +2383,10 @@ create_expression_by_pieces (basic_block block, tree expr, tree stmts)
{
tree op1 = TREE_OPERAND (expr, 0);
tree op2 = TREE_OPERAND (expr, 1);
tree genop1 = find_or_generate_expression (block, op1, stmts);
tree genop2 = find_or_generate_expression (block, op2, stmts);
tree genop1 = find_or_generate_expression (block, op1, stmts, domstmt);
tree genop2 = find_or_generate_expression (block, op2, stmts, domstmt);
if (!genop1 || !genop2)
return NULL_TREE;
folded = fold_build2 (TREE_CODE (expr), TREE_TYPE (expr),
genop1, genop2);
break;
@ -2345,7 +2395,9 @@ create_expression_by_pieces (basic_block block, tree expr, tree stmts)
case tcc_unary:
{
tree op1 = TREE_OPERAND (expr, 0);
tree genop1 = find_or_generate_expression (block, op1, stmts);
tree genop1 = find_or_generate_expression (block, op1, stmts, domstmt);
if (!genop1)
return NULL_TREE;
folded = fold_build1 (TREE_CODE (expr), TREE_TYPE (expr),
genop1);
break;
@ -2421,7 +2473,8 @@ create_expression_by_pieces (basic_block block, tree expr, tree stmts)
vn_add (name, v);
VN_INFO_GET (name)->valnum = name;
get_or_alloc_expression_id (name);
bitmap_value_replace_in_set (NEW_SETS (block), name);
if (!in_fre)
bitmap_value_replace_in_set (NEW_SETS (block), name);
bitmap_value_replace_in_set (AVAIL_OUT (block), name);
pre_stats.insertions++;
@ -2497,7 +2550,7 @@ insert_into_preds_of_block (basic_block block, unsigned int exprnum,
{
builtexpr = create_expression_by_pieces (bprime,
eprime,
stmts);
stmts, NULL_TREE);
gcc_assert (!(pred->flags & EDGE_ABNORMAL));
bsi_insert_on_edge (pred, stmts);
avail[bprime->index] = builtexpr;
@ -2659,7 +2712,7 @@ do_regular_insertion (basic_block block, basic_block dom)
vprime = get_value_handle (eprime);
gcc_assert (vprime);
edoubleprime = bitmap_find_leader (AVAIL_OUT (bprime),
vprime);
vprime, NULL_TREE);
if (edoubleprime == NULL)
{
avail[bprime->index] = eprime;
@ -2788,7 +2841,7 @@ do_partial_partial_insertion (basic_block block, basic_block dom)
vprime = get_value_handle (eprime);
gcc_assert (vprime);
edoubleprime = bitmap_find_leader (AVAIL_OUT (bprime),
vprime);
vprime, NULL_TREE);
if (edoubleprime == NULL)
{
by_all = false;
@ -2970,10 +3023,14 @@ find_existing_value_expr (tree t, VEC (tree, gc) *vuses)
replaced with the value handles of each of the operands of EXPR.
VUSES represent the virtual use operands associated with EXPR (if
any). Insert EXPR's operands into the EXP_GEN set for BLOCK. */
any). Insert EXPR's operands into the EXP_GEN set for BLOCK.
If CHECK_AVAIL is true, checks availability of each operand in
BLOCKs AVAIL_OUT set. */
static inline tree
create_value_expr_from (tree expr, basic_block block, VEC (tree, gc) *vuses)
create_value_expr_from (tree expr, basic_block block, VEC (tree, gc) *vuses,
bool check_avail)
{
int i;
enum tree_code code = TREE_CODE (expr);
@ -3021,7 +3078,7 @@ create_value_expr_from (tree expr, basic_block block, VEC (tree, gc) *vuses)
/* Recursively value-numberize reference ops and tree lists. */
if (REFERENCE_CLASS_P (op))
{
tree tempop = create_value_expr_from (op, block, vuses);
tree tempop = create_value_expr_from (op, block, vuses, check_avail);
op = tempop ? tempop : op;
val = vn_lookup_or_add_with_vuses (op, vuses);
set_expression_vuses (op, vuses);
@ -3037,6 +3094,11 @@ create_value_expr_from (tree expr, basic_block block, VEC (tree, gc) *vuses)
TREE_TYPE (val) = TREE_TYPE (TREE_OPERAND (vexpr, i));
TREE_OPERAND (vexpr, i) = val;
if (check_avail
&& TREE_CODE (val) == VALUE_HANDLE
&& !bitmap_set_contains_value (AVAIL_OUT (block), val))
return NULL_TREE;
}
efi = find_existing_value_expr (vexpr, vuses);
if (efi)
@ -3271,12 +3333,13 @@ make_values_for_stmt (tree stmt, basic_block block)
vuses = copy_vuses_from_stmt (stmt);
STRIP_USELESS_TYPE_CONVERSION (rhs);
if (can_value_number_operation (rhs)
&& (!lhsval || !is_gimple_min_invariant (lhsval)))
&& (!lhsval || !is_gimple_min_invariant (lhsval))
&& !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
{
/* For value numberable operation, create a
duplicate expression with the operands replaced
with the value handles of the original RHS. */
tree newt = create_value_expr_from (rhs, block, vuses);
tree newt = create_value_expr_from (rhs, block, vuses, false);
if (newt)
{
set_expression_vuses (newt, vuses);
@ -3480,8 +3543,6 @@ compute_avail (void)
else if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT
&& !ann->has_volatile_ops
&& TREE_CODE (GIMPLE_STMT_OPERAND (stmt, 0)) == SSA_NAME
&& (!SSA_NAME_OCCURS_IN_ABNORMAL_PHI
(GIMPLE_STMT_OPERAND (stmt, 0)))
&& !tree_could_throw_p (stmt))
{
if (make_values_for_stmt (stmt, block))
@ -3510,6 +3571,36 @@ compute_avail (void)
free (worklist);
}
/* Insert the expression for SSA_VN that SCCVN thought would be simpler
than the available expressions for it. The insertion point is
right before the first use in STMT. Returns the SSA_NAME that should
be used for replacement. */
static tree
do_SCCVN_insertion (tree stmt, tree ssa_vn)
{
basic_block bb = bb_for_stmt (stmt);
block_stmt_iterator bsi;
tree expr, stmts;
/* First create a value expression from the expression we want
to insert and associate it with the value handle for SSA_VN. */
expr = create_value_expr_from (VN_INFO (ssa_vn)->expr, bb, NULL, true);
if (expr == NULL_TREE)
return NULL_TREE;
set_value_handle (expr, get_value_handle (ssa_vn));
/* Then use create_expression_by_pieces to generate a valid
expression to insert at this point of the IL stream. */
stmts = alloc_stmt_list ();
expr = create_expression_by_pieces (bb, expr, stmts, stmt);
if (expr == NULL_TREE)
return NULL_TREE;
bsi = bsi_for_stmt (stmt);
bsi_insert_before (&bsi, stmts, BSI_SAME_STMT);
return expr;
}
/* Eliminate fully redundant computations. */
@ -3540,7 +3631,20 @@ eliminate (void)
tree sprime;
sprime = bitmap_find_leader (AVAIL_OUT (b),
get_value_handle (lhs));
get_value_handle (lhs), NULL_TREE);
/* If there is no existing usable leader but SCCVN thinks
it has an expression it wants to use as replacement,
insert that. */
if (!sprime
|| sprime == lhs)
{
tree val = VN_INFO (lhs)->valnum;
if (val != VN_TOP
&& VN_INFO (val)->needs_insertion
&& can_PRE_operation (VN_INFO (val)->expr))
sprime = do_SCCVN_insertion (stmt, val);
}
if (sprime
&& sprime != lhs
@ -3837,7 +3941,7 @@ execute_pre (bool do_fre)
insert_fake_stores ();
/* Collect and value number expressions computed in each basic block. */
if (!run_scc_vn ())
if (!run_scc_vn (do_fre))
{
if (!do_fre)
remove_dead_inserted_code ();
@ -3885,8 +3989,8 @@ execute_pre (bool do_fre)
}
bsi_commit_edge_inserts ();
free_scc_vn ();
clear_expression_ids ();
free_scc_vn ();
if (!do_fre)
{
remove_dead_inserted_code ();

98
gcc/tree-ssa-sccvn.c
View file

@ -221,6 +221,9 @@ tree VN_TOP;
static unsigned int next_dfs_num;
static VEC (tree, heap) *sccstack;
static bool may_insert;
DEF_VEC_P(vn_ssa_aux_t);
DEF_VEC_ALLOC_P(vn_ssa_aux_t, heap);
@ -525,8 +528,21 @@ copy_reference_ops_from_ref (tree ref, VEC(vn_reference_op_s, heap) **result)
temp.op1 = TREE_OPERAND (ref, 2);
break;
case COMPONENT_REF:
/* Record field as operand. */
temp.op0 = TREE_OPERAND (ref, 1);
/* If this is a reference to a union member, record the union
member size as operand. Do so only if we are doing
expression insertion (during FRE), as PRE currently gets
confused with this. */
if (may_insert
&& TREE_CODE (DECL_CONTEXT (TREE_OPERAND (ref, 1))) == UNION_TYPE
&& integer_zerop (DECL_FIELD_OFFSET (TREE_OPERAND (ref, 1)))
&& integer_zerop (DECL_FIELD_BIT_OFFSET (TREE_OPERAND (ref, 1))))
{
temp.type = NULL_TREE;
temp.op0 = TYPE_SIZE (TREE_TYPE (TREE_OPERAND (ref, 1)));
}
else
/* Record field as operand. */
temp.op0 = TREE_OPERAND (ref, 1);
break;
case ARRAY_RANGE_REF:
case ARRAY_REF:
@ -1017,6 +1033,9 @@ defs_to_varying (tree stmt)
return changed;
}
static tree
try_to_simplify (tree stmt, tree rhs);
/* Visit a copy between LHS and RHS, return true if the value number
changed. */
@ -1089,6 +1108,64 @@ visit_reference_op_load (tree lhs, tree op, tree stmt)
bool changed = false;
tree result = vn_reference_lookup (op, shared_vuses_from_stmt (stmt));
/* We handle type-punning through unions by value-numbering based
on offset and size of the access. Be prepared to handle a
type-mismatch here via creating a VIEW_CONVERT_EXPR. */
if (result
&& !useless_type_conversion_p (TREE_TYPE (result), TREE_TYPE (op)))
{
/* We will be setting the value number of lhs to the value number
of VIEW_CONVERT_EXPR <TREE_TYPE (result)> (result).
So first simplify and lookup this expression to see if it
is already available. */
tree val = fold_build1 (VIEW_CONVERT_EXPR, TREE_TYPE (op), result);
if (stmt
&& !is_gimple_min_invariant (val)
&& TREE_CODE (val) != SSA_NAME)
{
tree tem = try_to_simplify (stmt, val);
if (tem)
val = tem;
}
result = val;
if (!is_gimple_min_invariant (val)
&& TREE_CODE (val) != SSA_NAME)
result = vn_nary_op_lookup (val);
/* If the expression is not yet available, value-number lhs to
a new SSA_NAME we create. */
if (!result && may_insert)
{
result = make_ssa_name (SSA_NAME_VAR (lhs), NULL_TREE);
/* Initialize value-number information properly. */
VN_INFO_GET (result)->valnum = result;
VN_INFO (result)->expr = val;
VN_INFO (result)->needs_insertion = true;
/* As all "inserted" statements are singleton SCCs, insert
to the valid table. This is strictly needed to
avoid re-generating new value SSA_NAMEs for the same
expression during SCC iteration over and over (the
optimistic table gets cleared after each iteration).
We do not need to insert into the optimistic table, as
lookups there will fall back to the valid table. */
if (current_info == optimistic_info)
{
current_info = valid_info;
vn_nary_op_insert (val, result);
current_info = optimistic_info;
}
else
vn_nary_op_insert (val, result);
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "Inserting name ");
print_generic_expr (dump_file, result, 0);
fprintf (dump_file, " for expression ");
print_generic_expr (dump_file, val, 0);
fprintf (dump_file, "\n");
}
}
}
if (result)
{
changed = set_ssa_val_to (lhs, result);
@ -1496,7 +1573,8 @@ visit_use (tree use)
VN_INFO (use)->use_processed = true;
gcc_assert (!SSA_NAME_IN_FREE_LIST (use));
if (dump_file && (dump_flags & TDF_DETAILS))
if (dump_file && (dump_flags & TDF_DETAILS)
&& !IS_EMPTY_STMT (stmt))
{
fprintf (dump_file, "Value numbering ");
print_generic_expr (dump_file, use, 0);
@ -1607,6 +1685,9 @@ visit_use (tree use)
}
if (TREE_CODE (lhs) == SSA_NAME
/* We can substitute SSA_NAMEs that are live over
abnormal edges with their constant value. */
&& !is_gimple_min_invariant (rhs)
&& SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
changed = defs_to_varying (stmt);
else if (REFERENCE_CLASS_P (lhs) || DECL_P (lhs))
@ -1985,6 +2066,9 @@ free_scc_vn (void)
&& SSA_NAME_VALUE (name)
&& TREE_CODE (SSA_NAME_VALUE (name)) == VALUE_HANDLE)
SSA_NAME_VALUE (name) = NULL;
if (name
&& VN_INFO (name)->needs_insertion)
release_ssa_name (name);
}
obstack_free (&vn_ssa_aux_obstack, NULL);
VEC_free (vn_ssa_aux_t, heap, vn_ssa_aux_table);
@ -2005,11 +2089,13 @@ free_scc_vn (void)
due to ressource constraints. */
bool
run_scc_vn (void)
run_scc_vn (bool may_insert_arg)
{
size_t i;
tree param;
may_insert = may_insert_arg;
init_scc_vn ();
current_info = valid_info;
@ -2024,7 +2110,7 @@ run_scc_vn (void)
}
}
for (i = num_ssa_names - 1; i > 0; i--)
for (i = 1; i < num_ssa_names; ++i)
{
tree name = ssa_name (i);
if (name
@ -2033,6 +2119,7 @@ run_scc_vn (void)
if (!DFS (name))
{
free_scc_vn ();
may_insert = false;
return false;
}
}
@ -2058,5 +2145,6 @@ run_scc_vn (void)
}
}
may_insert = false;
return true;
}

7
gcc/tree-ssa-sccvn.h
View file

@ -44,12 +44,17 @@ typedef struct vn_ssa_aux
once. It cannot be used to avoid visitation for SSA_NAME's
involved in non-singleton SCC's. */
unsigned use_processed : 1;
/* Whether the SSA_NAME has no defining statement and thus an
insertion of such with EXPR as definition is required before
a use can be created of it. */
unsigned needs_insertion : 1;
} *vn_ssa_aux_t;
/* Return the value numbering info for an SSA_NAME. */
extern vn_ssa_aux_t VN_INFO (tree);
extern vn_ssa_aux_t VN_INFO_GET (tree);
bool run_scc_vn (void);
bool run_scc_vn (bool);
void free_scc_vn (void);
void switch_to_PRE_table (void);
tree vn_nary_op_lookup (tree);