Skip to content

R
riscv-gcc-1
Commit 927734cf by Xinliang David Li Committed by Xinliang David Li
Options

Fix PR/59303 -- uninit analysis enhancement 

From-SVN: r206309
parent c8ee48b8
Showing with 868 additions and 652 deletions
gcc/ChangeLog
2014-01-02 Xinliang David Li <davidxl@google.com>
PR tree-optimization/59303
* tree-ssa-uninit.c (is_use_properly_guarded):
Main cleanup.
(dump_predicates): Better output format.
(pred_equal_p): New function.
(is_neq_relop_p): Ditto.
(is_neq_zero_form_p): Ditto.
(pred_expr_equal_p): Ditto.
(pred_neg_p): Ditto.
(simplify_pred): Ditto.
(simplify_preds_2): Ditto.
(simplify_preds_3): Ditto.
(simplify_preds_4): Ditto.
(simplify_preds): Ditto.
(push_pred): Ditto.
(push_to_worklist): Ditto.
(get_pred_info_from_cmp): Ditto.
(is_degenerated_phi): Ditto.
(normalize_one_pred_1): Ditto.
(normalize_one_pred): Ditto.
(normalize_one_pred_chain): Ditto.
(normalize_preds): Ditto.
(normalize_cond_1): Remove function.
(normalize_cond): Ditto.
(is_gcond_subset_of): Ditto.
(is_subset_of_any): Ditto.
(is_or_set_subset_of): Ditto.
(is_and_set_subset_of): Ditto.
(is_norm_cond_subset_of): Ditto.
(pred_chain_length_cmp): Ditto.
(convert_control_dep_chain_into_preds): Type change.
(find_predicates): Ditto.
(find_def_preds): Ditto.
(destroy_predicates_vecs): Ditto.
(find_matching_predicates_in_rest_chains): Ditto.
(use_pred_not_overlap_with_undef_path_pred): Ditto.
(is_pred_expr_subset): Ditto.
(is_pred_chain_subset_of): Ditto.
(is_included_in): Ditto.
(is_superset_of): Ditto.
2014-01-02 Richard Sandiford <rdsandiford@googlemail.com>
Update copyright years
......
gcc/tree-ssa-uninit.c
......@@ -59,7 +59,7 @@ along with GCC; see the file COPYING3. If not see
/* Pointer set of potentially undefined ssa names, i.e.,
ssa names that are defined by phi with operands that
are not defined or potentially undefined. */
static struct pointer_set_t *possibly_undefined_names = 0;
static pointer_set_t *possibly_undefined_names = 0;
/* Bit mask handling macros. */
#define MASK_SET_BIT(mask, pos) mask |= (1 << pos)
......@@ -233,7 +233,7 @@ warn_uninitialized_vars (bool warn_possibly_uninitialized)
continue;
if (always_executed)
warn_uninit (OPT_Wuninitialized, use,
warn_uninit (OPT_Wuninitialized, use,
gimple_assign_rhs1 (stmt), base,
"%qE is used uninitialized in this function",
stmt);
......@@ -249,9 +249,9 @@ warn_uninitialized_vars (bool warn_possibly_uninitialized)
return 0;
}
/* Checks if the operand OPND of PHI is defined by
another phi with one operand defined by this PHI,
but the rest operands are all defined. If yes,
/* Checks if the operand OPND of PHI is defined by
another phi with one operand defined by this PHI,
but the rest operands are all defined. If yes,
returns true to skip this this operand as being
redundant. Can be enhanced to be more general. */
......@@ -411,7 +411,7 @@ compute_control_dep_chain (basic_block bb, basic_block dep_bb,
if (EDGE_COUNT (bb->succs) < 2)
return false;
/* Could use a set instead. */
/* Could use a set instead. */
cur_chain_len = cur_cd_chain->length ();
if (cur_chain_len > MAX_CHAIN_LEN)
return false;
......@@ -419,7 +419,7 @@ compute_control_dep_chain (basic_block bb, basic_block dep_bb,
for (i = 0; i < cur_chain_len; i++)
{
edge e = (*cur_cd_chain)[i];
/* cycle detected. */
/* Cycle detected. */
if (e->src == bb)
return false;
}
......@@ -444,7 +444,7 @@ compute_control_dep_chain (basic_block bb, basic_block dep_bb,
(*num_chains)++;
}
found_cd_chain = true;
/* check path from next edge. */
/* Check path from next edge. */
break;
}
......@@ -470,30 +470,41 @@ compute_control_dep_chain (basic_block bb, basic_block dep_bb,
return found_cd_chain;
}
typedef struct use_pred_info
/* The type to represent a simple predicate */
typedef struct use_def_pred_info
{
gimple cond;
tree pred_lhs;
tree pred_rhs;
enum tree_code cond_code;
bool invert;
} *use_pred_info_t;
} pred_info;
/* The type to represent a sequence of predicates grouped
with .AND. operation. */
typedef vec<pred_info, va_heap, vl_ptr> pred_chain;
/* The type to represent a sequence of pred_chains grouped
with .OR. operation. */
typedef vec<pred_chain, va_heap, vl_ptr> pred_chain_union;
/* Converts the chains of control dependence edges into a set of
predicates. A control dependence chain is represented by a vector
edges. DEP_CHAINS points to an array of dependence chains.
NUM_CHAINS is the size of the chain array. One edge in a dependence
chain is mapped to predicate expression represented by use_pred_info_t
chain is mapped to predicate expression represented by pred_info
type. One dependence chain is converted to a composite predicate that
is the result of AND operation of use_pred_info_t mapped to each edge.
A composite predicate is presented by a vector of use_pred_info_t. On
is the result of AND operation of pred_info mapped to each edge.
A composite predicate is presented by a vector of pred_info. On
return, *PREDS points to the resulting array of composite predicates.
*NUM_PREDS is the number of composite predictes. */
static bool
convert_control_dep_chain_into_preds (vec<edge> *dep_chains,
size_t num_chains,
vec<use_pred_info_t> **preds,
size_t *num_preds)
pred_chain_union *preds)
{
bool has_valid_pred = false;
size_t i, j;
......@@ -502,21 +513,20 @@ convert_control_dep_chain_into_preds (vec<edge> *dep_chains,
/* Now convert the control dep chain into a set
of predicates. */
typedef vec<use_pred_info_t> vec_use_pred_info_t_heap;
*preds = XCNEWVEC (vec_use_pred_info_t_heap, num_chains);
*num_preds = num_chains;
preds->reserve (num_chains);
for (i = 0; i < num_chains; i++)
{
vec<edge> one_cd_chain = dep_chains[i];
has_valid_pred = false;
pred_chain t_chain = vNULL;
for (j = 0; j < one_cd_chain.length (); j++)
{
gimple cond_stmt;
gimple_stmt_iterator gsi;
basic_block guard_bb;
use_pred_info_t one_pred;
pred_info one_pred;
edge e;
e = one_cd_chain[j];
......@@ -528,7 +538,7 @@ convert_control_dep_chain_into_preds (vec<edge> *dep_chains,
break;
}
cond_stmt = gsi_stmt (gsi);
if (gimple_code (cond_stmt) == GIMPLE_CALL
if (is_gimple_call (cond_stmt)
&& EDGE_COUNT (e->src->succs) >= 2)
{
/* Ignore EH edge. Can add assertion
......@@ -558,15 +568,18 @@ convert_control_dep_chain_into_preds (vec<edge> *dep_chains,
has_valid_pred = false;
break;
}
one_pred = XNEW (struct use_pred_info);
one_pred->cond = cond_stmt;
one_pred->invert = !!(e->flags & EDGE_FALSE_VALUE);
(*preds)[i].safe_push (one_pred);
one_pred.pred_lhs = gimple_cond_lhs (cond_stmt);
one_pred.pred_rhs = gimple_cond_rhs (cond_stmt);
one_pred.cond_code = gimple_cond_code (cond_stmt);
one_pred.invert = !!(e->flags & EDGE_FALSE_VALUE);
t_chain.safe_push (one_pred);
has_valid_pred = true;
}
if (!has_valid_pred)
break;
else
preds->safe_push (t_chain);
}
return has_valid_pred;
}
......@@ -577,8 +590,7 @@ convert_control_dep_chain_into_preds (vec<edge> *dep_chains,
the phi whose result is used in USE_BB. */
static bool
find_predicates (vec<use_pred_info_t> **preds,
size_t *num_preds,
find_predicates (pred_chain_union *preds,
basic_block phi_bb,
basic_block use_bb)
{
......@@ -610,8 +622,7 @@ find_predicates (vec<use_pred_info_t> **preds,
has_valid_pred
= convert_control_dep_chain_into_preds (dep_chains,
num_chains,
preds,
num_preds);
preds);
/* Free individual chain */
cur_chain.release ();
for (i = 0; i < num_chains; i++)
......@@ -629,7 +640,7 @@ find_predicates (vec<use_pred_info_t> **preds,
static void
collect_phi_def_edges (gimple phi, basic_block cd_root,
vec<edge> *edges,
struct pointer_set_t *visited_phis)
pointer_set_t *visited_phis)
{
size_t i, n;
edge opnd_edge;
......@@ -680,8 +691,7 @@ collect_phi_def_edges (gimple phi, basic_block cd_root,
composite predicates pointed to by PREDS. */
static bool
find_def_preds (vec<use_pred_info_t> **preds,
size_t *num_preds, gimple phi)
find_def_preds (pred_chain_union *preds, gimple phi)
{
size_t num_chains = 0, i, n;
vec<edge> *dep_chains = 0;
......@@ -689,7 +699,7 @@ find_def_preds (vec<use_pred_info_t> **preds,
vec<edge> def_edges = vNULL;
bool has_valid_pred = false;
basic_block phi_bb, cd_root = 0;
struct pointer_set_t *visited_phis;
pointer_set_t *visited_phis;
typedef vec<edge> vec_edge_heap;
dep_chains = XCNEWVEC (vec_edge_heap, MAX_NUM_CHAINS);
......@@ -739,8 +749,7 @@ find_def_preds (vec<use_pred_info_t> **preds,
has_valid_pred
= convert_control_dep_chain_into_preds (dep_chains,
num_chains,
preds,
num_preds);
preds);
for (i = 0; i < num_chains; i++)
dep_chains[i].release ();
free (dep_chains);
......@@ -750,16 +759,16 @@ find_def_preds (vec<use_pred_info_t> **preds,
/* Dumps the predicates (PREDS) for USESTMT. */
static void
dump_predicates (gimple usestmt, size_t num_preds,
vec<use_pred_info_t> *preds,
dump_predicates (gimple usestmt, pred_chain_union preds,
const char* msg)
{
size_t i, j;
vec<use_pred_info_t> one_pred_chain;
pred_chain one_pred_chain = vNULL;
fprintf (dump_file, msg);
print_gimple_stmt (dump_file, usestmt, 0, 0);
fprintf (dump_file, "is guarded by :\n");
/* do some dumping here: */
fprintf (dump_file, "is guarded by :\n\n");
size_t num_preds = preds.length ();
/* Do some dumping here: */
for (i = 0; i < num_preds; i++)
{
size_t np;
......@@ -769,37 +778,39 @@ dump_predicates (gimple usestmt, size_t num_preds,
for (j = 0; j < np; j++)
{
use_pred_info_t one_pred
= one_pred_chain[j];
if (one_pred->invert)
pred_info one_pred = one_pred_chain[j];
if (one_pred.invert)
fprintf (dump_file, " (.NOT.) ");
print_gimple_stmt (dump_file, one_pred->cond, 0, 0);
print_generic_expr (dump_file, one_pred.pred_lhs, 0);
fprintf (dump_file, " %s ", op_symbol_code (one_pred.cond_code));
print_generic_expr (dump_file, one_pred.pred_rhs, 0);
if (j < np - 1)
fprintf (dump_file, "(.AND.)\n");
fprintf (dump_file, " (.AND.) ");
else
fprintf (dump_file, "\n");
}
if (i < num_preds - 1)
fprintf (dump_file, "(.OR.)\n");
else
fprintf (dump_file, "\n\n");
}
}
/* Destroys the predicate set *PREDS. */
static void
destroy_predicate_vecs (size_t n,
vec<use_pred_info_t> * preds)
destroy_predicate_vecs (pred_chain_union preds)
{
size_t i, j;
size_t i;
size_t n = preds.length ();
for (i = 0; i < n; i++)
{
for (j = 0; j < preds[i].length (); j++)
free (preds[i][j]);
preds[i].release ();
}
free (preds);
preds[i].release ();
preds.release ();
}
/* Computes the 'normalized' conditional code with operand
/* Computes the 'normalized' conditional code with operand
swapping and condition inversion. */
static enum tree_code
......@@ -890,33 +901,33 @@ is_value_included_in (tree val, tree boundary, enum tree_code cmpc)
NUM_PRED_CHAIN is the size of array PREDS. */
static bool
find_matching_predicate_in_rest_chains (use_pred_info_t pred,
vec<use_pred_info_t> *preds,
find_matching_predicate_in_rest_chains (pred_info pred,
pred_chain_union preds,
size_t num_pred_chains)
{
size_t i, j, n;
/* trival case */
/* Trival case. */
if (num_pred_chains == 1)
return true;
for (i = 1; i < num_pred_chains; i++)
{
bool found = false;
vec<use_pred_info_t> one_chain = preds[i];
pred_chain one_chain = preds[i];
n = one_chain.length ();
for (j = 0; j < n; j++)
{
use_pred_info_t pred2
= one_chain[j];
/* can relax the condition comparison to not
pred_info pred2 = one_chain[j];
/* Can relax the condition comparison to not
use address comparison. However, the most common
case is that multiple control dependent paths share
a common path prefix, so address comparison should
be ok. */
if (pred2->cond == pred->cond
&& pred2->invert == pred->invert)
if (operand_equal_p (pred2.pred_lhs, pred.pred_lhs, 0)
&& operand_equal_p (pred2.pred_rhs, pred.pred_rhs, 0)
&& pred2.invert == pred.invert)
{
found = true;
break;
......@@ -934,7 +945,7 @@ is_use_properly_guarded (gimple use_stmt,
basic_block use_bb,
gimple phi,
unsigned uninit_opnds,
struct pointer_set_t *visited_phis);
pointer_set_t *visited_phis);
/* Returns true if all uninitialized opnds are pruned. Returns false
otherwise. PHI is the phi node with uninitialized operands,
......@@ -971,12 +982,13 @@ is_use_properly_guarded (gimple use_stmt,
*/
static bool
prune_uninit_phi_opnds_in_unrealizable_paths (
gimple phi, unsigned uninit_opnds,
gimple flag_def, tree boundary_cst,
enum tree_code cmp_code,
struct pointer_set_t *visited_phis,
bitmap *visited_flag_phis)
prune_uninit_phi_opnds_in_unrealizable_paths (gimple phi,
unsigned uninit_opnds,
gimple flag_def,
tree boundary_cst,
enum tree_code cmp_code,
pointer_set_t *visited_phis,
bitmap *visited_flag_phis)
{
unsigned i;
......@@ -1023,10 +1035,9 @@ prune_uninit_phi_opnds_in_unrealizable_paths (
/* Now recursively prune the uninitialized phi args. */
uninit_opnds_arg_phi = compute_uninit_opnds_pos (phi_arg_def);
if (!prune_uninit_phi_opnds_in_unrealizable_paths (
phi_arg_def, uninit_opnds_arg_phi,
flag_arg_def, boundary_cst, cmp_code,
visited_phis, visited_flag_phis))
if (!prune_uninit_phi_opnds_in_unrealizable_paths
(phi_arg_def, uninit_opnds_arg_phi, flag_arg_def,
boundary_cst, cmp_code, visited_phis, visited_flag_phis))
return false;
bitmap_clear_bit (*visited_flag_phis,
......@@ -1144,11 +1155,9 @@ prune_uninit_phi_opnds_in_unrealizable_paths (
static bool
use_pred_not_overlap_with_undef_path_pred (
size_t num_preds,
vec<use_pred_info_t> *preds,
gimple phi, unsigned uninit_opnds,
struct pointer_set_t *visited_phis)
use_pred_not_overlap_with_undef_path_pred (pred_chain_union preds,
gimple phi, unsigned uninit_opnds,
pointer_set_t *visited_phis)
{
unsigned int i, n;
gimple flag_def = 0;
......@@ -1156,9 +1165,10 @@ use_pred_not_overlap_with_undef_path_pred (
enum tree_code cmp_code;
bool swap_cond = false;
bool invert = false;
vec<use_pred_info_t> the_pred_chain;
pred_chain the_pred_chain = vNULL;
bitmap visited_flag_phis = NULL;
bool all_pruned = false;
size_t num_preds = preds.length ();
gcc_assert (num_preds > 0);
/* Find within the common prefix of multiple predicate chains
......@@ -1168,17 +1178,14 @@ use_pred_not_overlap_with_undef_path_pred (
n = the_pred_chain.length ();
for (i = 0; i < n; i++)
{
gimple cond;
tree cond_lhs, cond_rhs, flag = 0;
use_pred_info_t the_pred
= the_pred_chain[i];
pred_info the_pred = the_pred_chain[i];
cond = the_pred->cond;
invert = the_pred->invert;
cond_lhs = gimple_cond_lhs (cond);
cond_rhs = gimple_cond_rhs (cond);
cmp_code = gimple_cond_code (cond);
invert = the_pred.invert;
cond_lhs = the_pred.pred_lhs;
cond_rhs = the_pred.pred_rhs;
cmp_code = the_pred.cond_code;
if (cond_lhs != NULL_TREE && TREE_CODE (cond_lhs) == SSA_NAME
&& cond_rhs != NULL_TREE && is_gimple_constant (cond_rhs))
......@@ -1204,8 +1211,8 @@ use_pred_not_overlap_with_undef_path_pred (
if ((gimple_code (flag_def) == GIMPLE_PHI)
&& (gimple_bb (flag_def) == gimple_bb (phi))
&& find_matching_predicate_in_rest_chains (
the_pred, preds, num_preds))
&& find_matching_predicate_in_rest_chains (the_pred, preds,
num_preds))
break;
flag_def = 0;
......@@ -1235,668 +1242,847 @@ use_pred_not_overlap_with_undef_path_pred (
return all_pruned;
}
/* Returns true if TC is AND or OR */
/* The helper function returns true if two predicates X1 and X2
are equivalent. It assumes the expressions have already
properly re-associated. */
static inline bool
is_and_or_or (enum tree_code tc, tree typ)
pred_equal_p (pred_info x1, pred_info x2)
{
return (tc == BIT_IOR_EXPR
|| (tc == BIT_AND_EXPR
&& (typ == 0 || TREE_CODE (typ) == BOOLEAN_TYPE)));
}
enum tree_code c1, c2;
if (!operand_equal_p (x1.pred_lhs, x2.pred_lhs, 0)
|| !operand_equal_p (x1.pred_rhs, x2.pred_rhs, 0))
return false;
typedef struct norm_cond
{
vec<gimple> conds;
enum tree_code cond_code;
bool invert;
} *norm_cond_t;
c1 = x1.cond_code;
if (x1.invert != x2.invert)
c2 = invert_tree_comparison (x2.cond_code, false);
else
c2 = x2.cond_code;
return c1 == c2;
}
/* Normalizes gimple condition COND. The normalization follows
UD chains to form larger condition expression trees. NORM_COND
holds the normalized result. COND_CODE is the logical opcode
(AND or OR) of the normalized tree. */
/* Returns true if the predication is testing !=. */
static void
normalize_cond_1 (gimple cond,
norm_cond_t norm_cond,
enum tree_code cond_code)
static inline bool
is_neq_relop_p (pred_info pred)
{
enum gimple_code gc;
enum tree_code cur_cond_code;
tree rhs1, rhs2;
gc = gimple_code (cond);
if (gc != GIMPLE_ASSIGN)
{
norm_cond->conds.safe_push (cond);
return;
}
cur_cond_code = gimple_assign_rhs_code (cond);
rhs1 = gimple_assign_rhs1 (cond);
rhs2 = gimple_assign_rhs2 (cond);
if (cur_cond_code == NE_EXPR)
{
if (integer_zerop (rhs2)
&& (TREE_CODE (rhs1) == SSA_NAME))
normalize_cond_1 (
SSA_NAME_DEF_STMT (rhs1),
norm_cond, cond_code);
else if (integer_zerop (rhs1)
&& (TREE_CODE (rhs2) == SSA_NAME))
normalize_cond_1 (
SSA_NAME_DEF_STMT (rhs2),
norm_cond, cond_code);
else
norm_cond->conds.safe_push (cond);
return;
}
if (is_and_or_or (cur_cond_code, TREE_TYPE (rhs1))
&& (cond_code == cur_cond_code || cond_code == ERROR_MARK)
&& (TREE_CODE (rhs1) == SSA_NAME && TREE_CODE (rhs2) == SSA_NAME))
{
normalize_cond_1 (SSA_NAME_DEF_STMT (rhs1),
norm_cond, cur_cond_code);
normalize_cond_1 (SSA_NAME_DEF_STMT (rhs2),
norm_cond, cur_cond_code);
norm_cond->cond_code = cur_cond_code;
}
else
norm_cond->conds.safe_push (cond);
return (pred.cond_code == NE_EXPR && !pred.invert)
|| (pred.cond_code == EQ_EXPR && pred.invert);
}
/* See normalize_cond_1 for details. INVERT is a flag to indicate
if COND needs to be inverted or not. */
/* Returns true if pred is of the form X != 0. */
static void
normalize_cond (gimple cond, norm_cond_t norm_cond, bool invert)
static inline bool
is_neq_zero_form_p (pred_info pred)
{
enum tree_code cond_code;
if (!is_neq_relop_p (pred) || !integer_zerop (pred.pred_rhs)
|| TREE_CODE (pred.pred_lhs) != SSA_NAME)
return false;
return true;
}
norm_cond->cond_code = ERROR_MARK;
norm_cond->invert = false;
norm_cond->conds.create (0);
gcc_assert (gimple_code (cond) == GIMPLE_COND);
cond_code = gimple_cond_code (cond);
if (invert)
cond_code = invert_tree_comparison (cond_code, false);
/* The helper function returns true if two predicates X1
is equivalent to X2 != 0. */
if (cond_code == NE_EXPR)
{
if (integer_zerop (gimple_cond_rhs (cond))
&& (TREE_CODE (gimple_cond_lhs (cond)) == SSA_NAME))
normalize_cond_1 (
SSA_NAME_DEF_STMT (gimple_cond_lhs (cond)),
norm_cond, ERROR_MARK);
else if (integer_zerop (gimple_cond_lhs (cond))
&& (TREE_CODE (gimple_cond_rhs (cond)) == SSA_NAME))
normalize_cond_1 (
SSA_NAME_DEF_STMT (gimple_cond_rhs (cond)),
norm_cond, ERROR_MARK);
else
{
norm_cond->conds.safe_push (cond);
norm_cond->invert = invert;
}
}
else
{
norm_cond->conds.safe_push (cond);
norm_cond->invert = invert;
}
static inline bool
pred_expr_equal_p (pred_info x1, tree x2)
{
if (!is_neq_zero_form_p (x1))
return false;
gcc_assert (norm_cond->conds.length () == 1
|| is_and_or_or (norm_cond->cond_code, NULL));
return operand_equal_p (x1.pred_lhs, x2, 0);
}
/* Returns true if the domain for condition COND1 is a subset of
COND2. REVERSE is a flag. when it is true the function checks
if COND1 is a superset of COND2. INVERT1 and INVERT2 are flags
to indicate if COND1 and COND2 need to be inverted or not. */
/* Returns true of the domain of single predicate expression
EXPR1 is a subset of that of EXPR2. Returns false if it
can not be proved. */
static bool
is_gcond_subset_of (gimple cond1, bool invert1,
gimple cond2, bool invert2,
bool reverse)
is_pred_expr_subset_of (pred_info expr1, pred_info expr2)
{
enum gimple_code gc1, gc2;
enum tree_code cond1_code, cond2_code;
gimple tmp;
tree cond1_lhs, cond1_rhs, cond2_lhs, cond2_rhs;
enum tree_code code1, code2;
/* Take the short cut. */
if (cond1 == cond2)
if (pred_equal_p (expr1, expr2))
return true;
if (reverse)
{
tmp = cond1;
cond1 = cond2;
cond2 = tmp;
}
if ((TREE_CODE (expr1.pred_rhs) != INTEGER_CST)
|| (TREE_CODE (expr2.pred_rhs) != INTEGER_CST))
return false;
gc1 = gimple_code (cond1);
gc2 = gimple_code (cond2);
if (!operand_equal_p (expr1.pred_lhs, expr2.pred_lhs, 0))
return false;
if ((gc1 != GIMPLE_ASSIGN && gc1 != GIMPLE_COND)
|| (gc2 != GIMPLE_ASSIGN && gc2 != GIMPLE_COND))
return cond1 == cond2;
code1 = expr1.cond_code;
if (expr1.invert)
code1 = invert_tree_comparison (code1, false);
code2 = expr2.cond_code;
if (expr2.invert)
code2 = invert_tree_comparison (code2, false);
cond1_code = ((gc1 == GIMPLE_ASSIGN)
? gimple_assign_rhs_code (cond1)
: gimple_cond_code (cond1));
if (code1 != code2 && code2 != NE_EXPR)
return false;
cond2_code = ((gc2 == GIMPLE_ASSIGN)
? gimple_assign_rhs_code (cond2)
: gimple_cond_code (cond2));
if (is_value_included_in (expr1.pred_rhs, expr2.pred_rhs, code2))
return true;
if (TREE_CODE_CLASS (cond1_code) != tcc_comparison
|| TREE_CODE_CLASS (cond2_code) != tcc_comparison)
return false;
return false;
}
if (invert1)
cond1_code = invert_tree_comparison (cond1_code, false);
if (invert2)
cond2_code = invert_tree_comparison (cond2_code, false);
cond1_lhs = ((gc1 == GIMPLE_ASSIGN)
? gimple_assign_rhs1 (cond1)
: gimple_cond_lhs (cond1));
cond1_rhs = ((gc1 == GIMPLE_ASSIGN)
? gimple_assign_rhs2 (cond1)
: gimple_cond_rhs (cond1));
cond2_lhs = ((gc2 == GIMPLE_ASSIGN)
? gimple_assign_rhs1 (cond2)
: gimple_cond_lhs (cond2));
cond2_rhs = ((gc2 == GIMPLE_ASSIGN)
? gimple_assign_rhs2 (cond2)
: gimple_cond_rhs (cond2));
/* Assuming const operands have been swapped to the
rhs at this point of the analysis. */
if (cond1_lhs != cond2_lhs)
return false;
/* Returns true if the domain of PRED1 is a subset
of that of PRED2. Returns false if it can not be proved so. */
if (!is_gimple_constant (cond1_rhs)
|| TREE_CODE (cond1_rhs) != INTEGER_CST)
return (cond1_rhs == cond2_rhs);
if (!is_gimple_constant (cond2_rhs)
|| TREE_CODE (cond2_rhs) != INTEGER_CST)
return (cond1_rhs == cond2_rhs);
if (cond1_code == EQ_EXPR)
return is_value_included_in (cond1_rhs,
cond2_rhs, cond2_code);
if (cond1_code == NE_EXPR || cond2_code == EQ_EXPR)
return ((cond2_code == cond1_code)
&& tree_int_cst_equal (cond1_rhs, cond2_rhs));
if (((cond1_code == GE_EXPR || cond1_code == GT_EXPR)
&& (cond2_code == LE_EXPR || cond2_code == LT_EXPR))
|| ((cond1_code == LE_EXPR || cond1_code == LT_EXPR)
&& (cond2_code == GE_EXPR || cond2_code == GT_EXPR)))
return false;
static bool
is_pred_chain_subset_of (pred_chain pred1,
pred_chain pred2)
{
size_t np1, np2, i1, i2;
if (cond1_code != GE_EXPR && cond1_code != GT_EXPR
&& cond1_code != LE_EXPR && cond1_code != LT_EXPR)
return false;
np1 = pred1.length ();
np2 = pred2.length ();
if (cond1_code == GT_EXPR)
{
cond1_code = GE_EXPR;
cond1_rhs = fold_binary (PLUS_EXPR, TREE_TYPE (cond1_rhs),
cond1_rhs,
fold_convert (TREE_TYPE (cond1_rhs),
integer_one_node));
}
else if (cond1_code == LT_EXPR)
for (i2 = 0; i2 < np2; i2++)
{
cond1_code = LE_EXPR;
cond1_rhs = fold_binary (MINUS_EXPR, TREE_TYPE (cond1_rhs),
cond1_rhs,
fold_convert (TREE_TYPE (cond1_rhs),
integer_one_node));
bool found = false;
pred_info info2 = pred2[i2];
for (i1 = 0; i1 < np1; i1++)
{
pred_info info1 = pred1[i1];
if (is_pred_expr_subset_of (info1, info2))
{
found = true;
break;
}
}
if (!found)
return false;
}
if (!cond1_rhs)
return false;
gcc_assert (cond1_code == GE_EXPR || cond1_code == LE_EXPR);
if (cond2_code == GE_EXPR || cond2_code == GT_EXPR ||
cond2_code == LE_EXPR || cond2_code == LT_EXPR)
return is_value_included_in (cond1_rhs,
cond2_rhs, cond2_code);
else if (cond2_code == NE_EXPR)
return
(is_value_included_in (cond1_rhs,
cond2_rhs, cond2_code)
&& !is_value_included_in (cond2_rhs,
cond1_rhs, cond1_code));
return false;
return true;
}
/* Returns true if the domain of the condition expression
in COND is a subset of any of the sub-conditions
of the normalized condtion NORM_COND. INVERT is a flag
to indicate of the COND needs to be inverted.
REVERSE is a flag. When it is true, the check is reversed --
it returns true if COND is a superset of any of the subconditions
of NORM_COND. */
/* Returns true if the domain defined by
one pred chain ONE_PRED is a subset of the domain
of *PREDS. It returns false if ONE_PRED's domain is
not a subset of any of the sub-domains of PREDS
(corresponding to each individual chains in it), even
though it may be still be a subset of whole domain
of PREDS which is the union (ORed) of all its subdomains.
In other words, the result is conservative. */
static bool
is_subset_of_any (gimple cond, bool invert,
norm_cond_t norm_cond, bool reverse)
is_included_in (pred_chain one_pred, pred_chain_union preds)
{
size_t i;
size_t len = norm_cond->conds.length ();
size_t n = preds.length ();
for (i = 0; i < len; i++)
for (i = 0; i < n; i++)
{
if (is_gcond_subset_of (cond, invert,
norm_cond->conds[i],
false, reverse))
if (is_pred_chain_subset_of (one_pred, preds[i]))
return true;
}
return false;
}
/* NORM_COND1 and NORM_COND2 are normalized logical/BIT OR
expressions (formed by following UD chains not control
dependence chains). The function returns true of domain
of and expression NORM_COND1 is a subset of NORM_COND2's.
The implementation is conservative, and it returns false if
it the inclusion relationship may not hold. */
/* Compares two predicate sets PREDS1 and PREDS2 and returns
true if the domain defined by PREDS1 is a superset
of PREDS2's domain. N1 and N2 are array sizes of PREDS1 and
PREDS2 respectively. The implementation chooses not to build
generic trees (and relying on the folding capability of the
compiler), but instead performs brute force comparison of
individual predicate chains (won't be a compile time problem
as the chains are pretty short). When the function returns
false, it does not necessarily mean *PREDS1 is not a superset
of *PREDS2, but mean it may not be so since the analysis can
not prove it. In such cases, false warnings may still be
emitted. */
static bool
is_or_set_subset_of (norm_cond_t norm_cond1,
norm_cond_t norm_cond2)
is_superset_of (pred_chain_union preds1, pred_chain_union preds2)
{
size_t i;
size_t len = norm_cond1->conds.length ();
size_t i, n2;
pred_chain one_pred_chain = vNULL;
for (i = 0; i < len; i++)
n2 = preds2.length ();
for (i = 0; i < n2; i++)
{
if (!is_subset_of_any (norm_cond1->conds[i],
false, norm_cond2, false))
one_pred_chain = preds2[i];
if (!is_included_in (one_pred_chain, preds1))
return false;
}
return true;
}
/* NORM_COND1 and NORM_COND2 are normalized logical AND
expressions (formed by following UD chains not control
dependence chains). The function returns true of domain
of and expression NORM_COND1 is a subset of NORM_COND2's. */
/* Returns true if TC is AND or OR. */
static bool
is_and_set_subset_of (norm_cond_t norm_cond1,
norm_cond_t norm_cond2)
static inline bool
is_and_or_or_p (enum tree_code tc, tree type)
{
size_t i;
size_t len = norm_cond2->conds.length ();
return (tc == BIT_IOR_EXPR
|| (tc == BIT_AND_EXPR
&& (type == 0 || TREE_CODE (type) == BOOLEAN_TYPE)));
}
for (i = 0; i < len; i++)
{
if (!is_subset_of_any (norm_cond2->conds[i],
false, norm_cond1, true))
return false;
}
return true;
/* Returns true if X1 is the negate of X2. */
static inline bool
pred_neg_p (pred_info x1, pred_info x2)
{
enum tree_code c1, c2;
if (!operand_equal_p (x1.pred_lhs, x2.pred_lhs, 0)
|| !operand_equal_p (x1.pred_rhs, x2.pred_rhs, 0))
return false;
c1 = x1.cond_code;
if (x1.invert == x2.invert)
c2 = invert_tree_comparison (x2.cond_code, false);
else
c2 = x2.cond_code;
return c1 == c2;
}
/* Returns true of the domain if NORM_COND1 is a subset
of that of NORM_COND2. Returns false if it can not be
proved to be so. */
/* 1) ((x IOR y) != 0) AND (x != 0) is equivalent to (x != 0);
2) (X AND Y) OR (!X AND Y) is equivalent to Y;
3) X OR (!X AND Y) is equivalent to (X OR Y);
4) ((x IAND y) != 0) || (x != 0 AND y != 0)) is equivalent to
(x != 0 AND y != 0)
5) (X AND Y) OR (!X AND Z) OR (!Y AND Z) is equivalent to
(X AND Y) OR Z
static bool
is_norm_cond_subset_of (norm_cond_t norm_cond1,
norm_cond_t norm_cond2)
PREDS is the predicate chains, and N is the number of chains. */
/* Helper function to implement rule 1 above. ONE_CHAIN is
the AND predication to be simplified. */
static void
simplify_pred (pred_chain *one_chain)
{
size_t i;
enum tree_code code1, code2;
size_t i, j, n;
bool simplified = false;
pred_chain s_chain = vNULL;
code1 = norm_cond1->cond_code;
code2 = norm_cond2->cond_code;
n = one_chain->length ();
if (code1 == BIT_AND_EXPR)
for (i = 0; i < n; i++)
{
/* Both conditions are AND expressions. */
if (code2 == BIT_AND_EXPR)
return is_and_set_subset_of (norm_cond1, norm_cond2);
/* NORM_COND1 is an AND expression, and NORM_COND2 is an OR
expression. In this case, returns true if any subexpression
of NORM_COND1 is a subset of any subexpression of NORM_COND2. */
else if (code2 == BIT_IOR_EXPR)
pred_info *a_pred = &(*one_chain)[i];
if (!a_pred->pred_lhs)
continue;
if (!is_neq_zero_form_p (*a_pred))
continue;
gimple def_stmt = SSA_NAME_DEF_STMT (a_pred->pred_lhs);
if (gimple_code (def_stmt) != GIMPLE_ASSIGN)
continue;
if (gimple_assign_rhs_code (def_stmt) == BIT_IOR_EXPR)
{
size_t len1;
len1 = norm_cond1->conds.length ();
for (i = 0; i < len1; i++)
for (j = 0; j < n; j++)
{
gimple cond1 = norm_cond1->conds[i];
if (is_subset_of_any (cond1, false, norm_cond2, false))
return true;
pred_info *b_pred = &(*one_chain)[j];
if (!b_pred->pred_lhs)
continue;
if (!is_neq_zero_form_p (*b_pred))
continue;
if (pred_expr_equal_p (*b_pred, gimple_assign_rhs1 (def_stmt))
|| pred_expr_equal_p (*b_pred, gimple_assign_rhs2 (def_stmt)))
{
/* Mark a_pred for removal. */
a_pred->pred_lhs = NULL;
a_pred->pred_rhs = NULL;
simplified = true;
break;
}
}
return false;
}
else
{
gcc_assert (code2 == ERROR_MARK);
gcc_assert (norm_cond2->conds.length () == 1);
return is_subset_of_any (norm_cond2->conds[0],
norm_cond2->invert, norm_cond1, true);
}
}
/* NORM_COND1 is an OR expression */
else if (code1 == BIT_IOR_EXPR)
{
if (code2 != code1)
return false;
return is_or_set_subset_of (norm_cond1, norm_cond2);
}
else
{
gcc_assert (code1 == ERROR_MARK);
gcc_assert (norm_cond1->conds.length () == 1);
/* Conservatively returns false if NORM_COND1 is non-decomposible
and NORM_COND2 is an AND expression. */
if (code2 == BIT_AND_EXPR)
return false;
if (code2 == BIT_IOR_EXPR)
return is_subset_of_any (norm_cond1->conds[0],
norm_cond1->invert, norm_cond2, false);
if (!simplified)
return;
gcc_assert (code2 == ERROR_MARK);
gcc_assert (norm_cond2->conds.length () == 1);
return is_gcond_subset_of (norm_cond1->conds[0],
norm_cond1->invert,
norm_cond2->conds[0],
norm_cond2->invert, false);
for (i = 0; i < n; i++)
{
pred_info *a_pred = &(*one_chain)[i];
if (!a_pred->pred_lhs)
continue;
s_chain.safe_push (*a_pred);
}
one_chain->release ();
*one_chain = s_chain;
}
/* Returns true of the domain of single predicate expression
EXPR1 is a subset of that of EXPR2. Returns false if it
can not be proved. */
/* The helper function implements the rule 2 for the
OR predicate PREDS.
2) (X AND Y) OR (!X AND Y) is equivalent to Y. */
static bool
is_pred_expr_subset_of (use_pred_info_t expr1,
use_pred_info_t expr2)
simplify_preds_2 (pred_chain_union *preds)
{
gimple cond1, cond2;
enum tree_code code1, code2;
struct norm_cond norm_cond1, norm_cond2;
bool is_subset = false;
size_t i, j, n;
bool simplified = false;
pred_chain_union s_preds = vNULL;
cond1 = expr1->cond;
cond2 = expr2->cond;
code1 = gimple_cond_code (cond1);
code2 = gimple_cond_code (cond2);
/* (X AND Y) OR (!X AND Y) is equivalent to Y.
(X AND Y) OR (X AND !Y) is equivalent to X. */
if (expr1->invert)
code1 = invert_tree_comparison (code1, false);
if (expr2->invert)
code2 = invert_tree_comparison (code2, false);
n = preds->length ();
for (i = 0; i < n; i++)
{
pred_info x, y;
pred_chain *a_chain = &(*preds)[i];
/* Fast path -- match exactly */
if ((gimple_cond_lhs (cond1) == gimple_cond_lhs (cond2))
&& (gimple_cond_rhs (cond1) == gimple_cond_rhs (cond2))
&& (code1 == code2))
return true;
if (a_chain->length () != 2)
continue;
x = (*a_chain)[0];
y = (*a_chain)[1];
for (j = 0; j < n; j++)
{
pred_chain *b_chain;
pred_info x2, y2;
if (j == i)
continue;
b_chain = &(*preds)[j];
if (b_chain->length () != 2)
continue;
/* Normalize conditions. To keep NE_EXPR, do not invert
with both need inversion. */
normalize_cond (cond1, &norm_cond1, (expr1->invert));
normalize_cond (cond2, &norm_cond2, (expr2->invert));
x2 = (*b_chain)[0];
y2 = (*b_chain)[1];
is_subset = is_norm_cond_subset_of (&norm_cond1, &norm_cond2);
if (pred_equal_p (x, x2) && pred_neg_p (y, y2))
{
/* Kill a_chain. */
a_chain->release ();
b_chain->release ();
b_chain->safe_push (x);
simplified = true;
break;
}
if (pred_neg_p (x, x2) && pred_equal_p (y, y2))
{
/* Kill a_chain. */
a_chain->release ();
b_chain->release ();
b_chain->safe_push (y);
simplified = true;
break;
}
}
}
/* Now clean up the chain. */
if (simplified)
{
for (i = 0; i < n; i++)
{
if ((*preds)[i].is_empty ())
continue;
s_preds.safe_push ((*preds)[i]);
}
preds->release ();
(*preds) = s_preds;
s_preds = vNULL;
}
/* Free memory */
norm_cond1.conds.release ();
norm_cond2.conds.release ();
return is_subset ;
return simplified;
}
/* Returns true if the domain of PRED1 is a subset
of that of PRED2. Returns false if it can not be proved so. */
/* The helper function implements the rule 2 for the
OR predicate PREDS.
3) x OR (!x AND y) is equivalent to x OR y. */
static bool
is_pred_chain_subset_of (vec<use_pred_info_t> pred1,
vec<use_pred_info_t> pred2)
simplify_preds_3 (pred_chain_union *preds)
{
size_t np1, np2, i1, i2;
size_t i, j, n;
bool simplified = false;
np1 = pred1.length ();
np2 = pred2.length ();
/* Now iteratively simplify X OR (!X AND Z ..)
into X OR (Z ...). */
for (i2 = 0; i2 < np2; i2++)
n = preds->length ();
if (n < 2)
return false;
for (i = 0; i < n; i++)
{
bool found = false;
use_pred_info_t info2
= pred2[i2];
for (i1 = 0; i1 < np1; i1++)
pred_info x;
pred_chain *a_chain = &(*preds)[i];
if (a_chain->length () != 1)
continue;
x = (*a_chain)[0];
for (j = 0; j < n; j++)
{
use_pred_info_t info1
= pred1[i1];
if (is_pred_expr_subset_of (info1, info2))
pred_chain *b_chain;
pred_info x2;
size_t k;
if (j == i)
continue;
b_chain = &(*preds)[j];
if (b_chain->length () < 2)
continue;
for (k = 0; k < b_chain->length (); k++)
{
found = true;
break;
x2 = (*b_chain)[k];
if (pred_neg_p (x, x2))
{
b_chain->unordered_remove (k);
simplified = true;
break;
}
}
}
if (!found)
return false;
}
return true;
return simplified;
}
/* Returns true if the domain defined by
one pred chain ONE_PRED is a subset of the domain
of *PREDS. It returns false if ONE_PRED's domain is
not a subset of any of the sub-domains of PREDS (
corresponding to each individual chains in it), even
though it may be still be a subset of whole domain
of PREDS which is the union (ORed) of all its subdomains.
In other words, the result is conservative. */
/* The helper function implements the rule 4 for the
OR predicate PREDS.
2) ((x AND y) != 0) OR (x != 0 AND y != 0) is equivalent to
(x != 0 ANd y != 0). */
static bool
is_included_in (vec<use_pred_info_t> one_pred,
vec<use_pred_info_t> *preds,
size_t n)
simplify_preds_4 (pred_chain_union *preds)
{
size_t i;
size_t i, j, n;
bool simplified = false;
pred_chain_union s_preds = vNULL;
gimple def_stmt;
n = preds->length ();
for (i = 0; i < n; i++)
{
if (is_pred_chain_subset_of (one_pred, preds[i]))
return true;
pred_info z;
pred_chain *a_chain = &(*preds)[i];
if (a_chain->length () != 1)
continue;
z = (*a_chain)[0];
if (!is_neq_zero_form_p (z))
continue;
def_stmt = SSA_NAME_DEF_STMT (z.pred_lhs);
if (gimple_code (def_stmt) != GIMPLE_ASSIGN)
continue;
if (gimple_assign_rhs_code (def_stmt) != BIT_AND_EXPR)
continue;
for (j = 0; j < n; j++)
{
pred_chain *b_chain;
pred_info x2, y2;
if (j == i)
continue;
b_chain = &(*preds)[j];
if (b_chain->length () != 2)
continue;
x2 = (*b_chain)[0];
y2 = (*b_chain)[1];
if (!is_neq_zero_form_p (x2)
|| !is_neq_zero_form_p (y2))
continue;
if ((pred_expr_equal_p (x2, gimple_assign_rhs1 (def_stmt))
&& pred_expr_equal_p (y2, gimple_assign_rhs2 (def_stmt)))
|| (pred_expr_equal_p (x2, gimple_assign_rhs2 (def_stmt))
&& pred_expr_equal_p (y2, gimple_assign_rhs1 (def_stmt))))
{
/* Kill a_chain. */
a_chain->release ();
simplified = true;
break;
}
}
}
/* Now clean up the chain. */
if (simplified)
{
for (i = 0; i < n; i++)
{
if ((*preds)[i].is_empty ())
continue;
s_preds.safe_push ((*preds)[i]);
}
preds->release ();
(*preds) = s_preds;
s_preds = vNULL;
}
return false;
return simplified;
}
/* compares two predicate sets PREDS1 and PREDS2 and returns
true if the domain defined by PREDS1 is a superset
of PREDS2's domain. N1 and N2 are array sizes of PREDS1 and
PREDS2 respectively. The implementation chooses not to build
generic trees (and relying on the folding capability of the
compiler), but instead performs brute force comparison of
individual predicate chains (won't be a compile time problem
as the chains are pretty short). When the function returns
false, it does not necessarily mean *PREDS1 is not a superset
of *PREDS2, but mean it may not be so since the analysis can
not prove it. In such cases, false warnings may still be
emitted. */
static bool
is_superset_of (vec<use_pred_info_t> *preds1,
size_t n1,
vec<use_pred_info_t> *preds2,
size_t n2)
/* This function simplifies predicates in PREDS. */
static void
simplify_preds (pred_chain_union *preds, gimple use_or_def, bool is_use)
{
size_t i;
vec<use_pred_info_t> one_pred_chain;
size_t i, n;
bool changed = false;
for (i = 0; i < n2; i++)
if (dump_file && dump_flags & TDF_DETAILS)
{
one_pred_chain = preds2[i];
if (!is_included_in (one_pred_chain, preds1, n1))
return false;
fprintf (dump_file, "[BEFORE SIMPLICATION -- ");
dump_predicates (use_or_def, *preds, is_use ? "[USE]:\n" : "[DEF]:\n");
}
return true;
for (i = 0; i < preds->length (); i++)
simplify_pred (&(*preds)[i]);
n = preds->length ();
if (n < 2)
return;
do
{
changed = false;
if (simplify_preds_2 (preds))
changed = true;
/* Now iteratively simplify X OR (!X AND Z ..)
into X OR (Z ...). */
if (simplify_preds_3 (preds))
changed = true;
if (simplify_preds_4 (preds))
changed = true;
} while (changed);
return;
}
/* Comparison function used by qsort. It is used to
sort predicate chains to allow predicate
simplification. */
/* This is a helper function which attempts to normalize predicate chains
by following UD chains. It basically builds up a big tree of either IOR
operations or AND operations, and convert the IOR tree into a
pred_chain_union or BIT_AND tree into a pred_chain.
Example:
static int
pred_chain_length_cmp (const void *p1, const void *p2)
_3 = _2 RELOP1 _1;
_6 = _5 RELOP2 _4;
_9 = _8 RELOP3 _7;
_10 = _3 | _6;
_12 = _9 | _0;
_t = _10 | _12;
then _t != 0 will be normalized into a pred_chain_union
(_2 RELOP1 _1) OR (_5 RELOP2 _4) OR (_8 RELOP3 _7) OR (_0 != 0)
Similarly given,
_3 = _2 RELOP1 _1;
_6 = _5 RELOP2 _4;
_9 = _8 RELOP3 _7;
_10 = _3 & _6;
_12 = _9 & _0;
then _t != 0 will be normalized into a pred_chain:
(_2 RELOP1 _1) AND (_5 RELOP2 _4) AND (_8 RELOP3 _7) AND (_0 != 0)
*/
/* This is a helper function that stores a PRED into NORM_PREDS. */
inline static void
push_pred (pred_chain_union *norm_preds, pred_info pred)
{
use_pred_info_t i1, i2;
vec<use_pred_info_t> const *chain1
= (vec<use_pred_info_t> const *)p1;
vec<use_pred_info_t> const *chain2
= (vec<use_pred_info_t> const *)p2;
pred_chain pred_chain = vNULL;
pred_chain.safe_push (pred);
norm_preds->safe_push (pred_chain);
}
if (chain1->length () != chain2->length ())
return (chain1->length () - chain2->length ());
/* A helper function that creates a predicate of the form
OP != 0 and push it WORK_LIST. */
i1 = (*chain1)[0];
i2 = (*chain2)[0];
inline static void
push_to_worklist (tree op, vec<pred_info, va_heap, vl_ptr> *work_list)
{
pred_info arg_pred;
arg_pred.pred_lhs = op;
arg_pred.pred_rhs = integer_zero_node;
arg_pred.cond_code = NE_EXPR;
arg_pred.invert = false;
work_list->safe_push (arg_pred);
}
/* Allow predicates with similar prefix come together. */
if (!i1->invert && i2->invert)
return -1;
else if (i1->invert && !i2->invert)
return 1;
/* A helper that generates a pred_info from a gimple assignment
CMP_ASSIGN with comparison rhs. */
return gimple_uid (i1->cond) - gimple_uid (i2->cond);
static pred_info
get_pred_info_from_cmp (gimple cmp_assign)
{
pred_info n_pred;
n_pred.pred_lhs = gimple_assign_rhs1 (cmp_assign);
n_pred.pred_rhs = gimple_assign_rhs2 (cmp_assign);
n_pred.cond_code = gimple_assign_rhs_code (cmp_assign);
n_pred.invert = false;
return n_pred;
}
/* x OR (!x AND y) is equivalent to x OR y.
This function normalizes x1 OR (!x1 AND x2) OR (!x1 AND !x2 AND x3)
into x1 OR x2 OR x3. PREDS is the predicate chains, and N is
the number of chains. Returns true if normalization happens. */
/* Returns true if the PHI is a degenerated phi with
all args with the same value (relop). In that case, *PRED
will be updated to that value. */
static bool
normalize_preds (vec<use_pred_info_t> *preds, size_t *n)
is_degenerated_phi (gimple phi, pred_info *pred_p)
{
size_t i, j, ll;
vec<use_pred_info_t> pred_chain;
vec<use_pred_info_t> x = vNULL;
use_pred_info_t xj = 0, nxj = 0;
int i, n;
tree op0;
gimple def0;
pred_info pred0;
if (*n < 2)
n = gimple_phi_num_args (phi);
op0 = gimple_phi_arg_def (phi, 0);
if (TREE_CODE (op0) != SSA_NAME)
return false;
/* First sort the chains in ascending order of lengths. */
qsort (preds, *n, sizeof (void *), pred_chain_length_cmp);
pred_chain = preds[0];
ll = pred_chain.length ();
if (ll != 1)
{
if (ll == 2)
{
use_pred_info_t xx, yy, xx2, nyy;
vec<use_pred_info_t> pred_chain2 = preds[1];
if (pred_chain2.length () != 2)
return false;
/* See if simplification x AND y OR x AND !y is possible. */
xx = pred_chain[0];
yy = pred_chain[1];
xx2 = pred_chain2[0];
nyy = pred_chain2[1];
if (gimple_cond_lhs (xx->cond) != gimple_cond_lhs (xx2->cond)
|| gimple_cond_rhs (xx->cond) != gimple_cond_rhs (xx2->cond)
|| gimple_cond_code (xx->cond) != gimple_cond_code (xx2->cond)
|| (xx->invert != xx2->invert))
return false;
if (gimple_cond_lhs (yy->cond) != gimple_cond_lhs (nyy->cond)
|| gimple_cond_rhs (yy->cond) != gimple_cond_rhs (nyy->cond)
|| gimple_cond_code (yy->cond) != gimple_cond_code (nyy->cond)
|| (yy->invert == nyy->invert))
return false;
/* Now merge the first two chains. */
free (yy);
free (nyy);
free (xx2);
pred_chain.release ();
pred_chain2.release ();
pred_chain.safe_push (xx);
preds[0] = pred_chain;
for (i = 1; i < *n - 1; i++)
preds[i] = preds[i + 1];
preds[*n - 1].create (0);
*n = *n - 1;
}
else
return false;
}
x.safe_push (pred_chain[0]);
/* The loop extracts x1, x2, x3, etc from chains
x1 OR (!x1 AND x2) OR (!x1 AND !x2 AND x3) OR ... */
for (i = 1; i < *n; i++)
def0 = SSA_NAME_DEF_STMT (op0);
if (gimple_code (def0) != GIMPLE_ASSIGN)
return false;
if (TREE_CODE_CLASS (gimple_assign_rhs_code (def0))
!= tcc_comparison)
return false;
pred0 = get_pred_info_from_cmp (def0);
for (i = 1; i < n; ++i)
{
pred_chain = preds[i];
if (pred_chain.length () != i + 1)
gimple def;
pred_info pred;
tree op = gimple_phi_arg_def (phi, i);
if (TREE_CODE (op) != SSA_NAME)
return false;
for (j = 0; j < i; j++)
def = SSA_NAME_DEF_STMT (op);
if (gimple_code (def) != GIMPLE_ASSIGN)
return false;
if (TREE_CODE_CLASS (gimple_assign_rhs_code (def))
!= tcc_comparison)
return false;
pred = get_pred_info_from_cmp (def);
if (!pred_equal_p (pred, pred0))
return false;
}
*pred_p = pred0;
return true;
}
/* Normalize one predicate PRED
1) if PRED can no longer be normlized, put it into NORM_PREDS.
2) otherwise if PRED is of the form x != 0, follow x's definition
and put normalized predicates into WORK_LIST. */
static void
normalize_one_pred_1 (pred_chain_union *norm_preds,
pred_chain *norm_chain,
pred_info pred,
enum tree_code and_or_code,
vec<pred_info, va_heap, vl_ptr> *work_list)
{
if (!is_neq_zero_form_p (pred))
{
if (and_or_code == BIT_IOR_EXPR)
push_pred (norm_preds, pred);
else
norm_chain->safe_push (pred);
return;
}
gimple def_stmt = SSA_NAME_DEF_STMT (pred.pred_lhs);
if (gimple_code (def_stmt) == GIMPLE_PHI
&& is_degenerated_phi (def_stmt, &pred))
work_list->safe_push (pred);
else if (gimple_code (def_stmt) == GIMPLE_PHI
&& and_or_code == BIT_IOR_EXPR)
{
int i, n;
n = gimple_phi_num_args (def_stmt);
/* If we see non zero constant, we should punt. The predicate
* should be one guarding the phi edge. */
for (i = 0; i < n; ++i)
{
xj = x[j];
nxj = pred_chain[j];
/* Check if nxj is !xj */
if (gimple_cond_lhs (xj->cond) != gimple_cond_lhs (nxj->cond)
|| gimple_cond_rhs (xj->cond) != gimple_cond_rhs (nxj->cond)
|| gimple_cond_code (xj->cond) != gimple_cond_code (nxj->cond)
|| (xj->invert == nxj->invert))
return false;
tree op = gimple_phi_arg_def (def_stmt, i);
if (TREE_CODE (op) == INTEGER_CST && !integer_zerop (op))
{
push_pred (norm_preds, pred);
return;
}
}
x.safe_push (pred_chain[i]);
}
for (i = 0; i < n; ++i)
{
tree op = gimple_phi_arg_def (def_stmt, i);
if (integer_zerop (op))
continue;
push_to_worklist (op, work_list);
}
}
else if (gimple_code (def_stmt) != GIMPLE_ASSIGN)
{
if (and_or_code == BIT_IOR_EXPR)
push_pred (norm_preds, pred);
else
norm_chain->safe_push (pred);
}
else if (gimple_assign_rhs_code (def_stmt) == and_or_code)
{
push_to_worklist (gimple_assign_rhs1 (def_stmt),
work_list);
push_to_worklist (gimple_assign_rhs2 (def_stmt),
work_list);
}
else if (TREE_CODE_CLASS (gimple_assign_rhs_code (def_stmt))
== tcc_comparison)
{
pred_info n_pred = get_pred_info_from_cmp (def_stmt);
if (and_or_code == BIT_IOR_EXPR)
push_pred (norm_preds, n_pred);
else
norm_chain->safe_push (n_pred);
}
else
{
if (and_or_code == BIT_IOR_EXPR)
push_pred (norm_preds, pred);
else
norm_chain->safe_push (pred);
}
}
/* Normalize PRED and store the normalized predicates into NORM_PREDS. */
static void
normalize_one_pred (pred_chain_union *norm_preds,
pred_info pred)
{
vec<pred_info, va_heap, vl_ptr> work_list = vNULL;
enum tree_code and_or_code = ERROR_MARK;
pred_chain norm_chain = vNULL;
/* Now normalize the pred chains using the extraced x1, x2, x3 etc. */
for (j = 0; j < *n; j++)
if (!is_neq_zero_form_p (pred))
{
use_pred_info_t t;
xj = x[j];
push_pred (norm_preds, pred);
return;
}
t = XNEW (struct use_pred_info);
*t = *xj;
gimple def_stmt = SSA_NAME_DEF_STMT (pred.pred_lhs);
if (gimple_code (def_stmt) == GIMPLE_ASSIGN)
and_or_code = gimple_assign_rhs_code (def_stmt);
if (and_or_code != BIT_IOR_EXPR
&& and_or_code != BIT_AND_EXPR)
{
if (TREE_CODE_CLASS (and_or_code)
== tcc_comparison)
{
pred_info n_pred = get_pred_info_from_cmp (def_stmt);
push_pred (norm_preds, n_pred);
}
else
push_pred (norm_preds, pred);
return;
}
x[j] = t;
work_list.safe_push (pred);
while (!work_list.is_empty ())
{
pred_info a_pred = work_list.pop ();
normalize_one_pred_1 (norm_preds, &norm_chain, a_pred,
and_or_code, &work_list);
}
if (and_or_code == BIT_AND_EXPR)
norm_preds->safe_push (norm_chain);
work_list.release ();
}
for (i = 0; i < *n; i++)
static void
normalize_one_pred_chain (pred_chain_union *norm_preds,
pred_chain one_chain)
{
vec<pred_info, va_heap, vl_ptr> work_list = vNULL;
pred_chain norm_chain = vNULL;
size_t i;
for (i = 0; i < one_chain.length (); i++)
work_list.safe_push (one_chain[i]);
while (!work_list.is_empty ())
{
pred_chain = preds[i];
for (j = 0; j < pred_chain.length (); j++)
free (pred_chain[j]);
pred_chain.release ();
/* A new chain. */
pred_chain.safe_push (x[i]);
preds[i] = pred_chain;
pred_info a_pred = work_list.pop ();
normalize_one_pred_1 (0, &norm_chain, a_pred,
BIT_AND_EXPR, &work_list);
}
return true;
norm_preds->safe_push (norm_chain);
work_list.release ();
}
/* Normalize predicate chains PREDS and returns the normalized one. */
static pred_chain_union
normalize_preds (pred_chain_union preds, gimple use_or_def, bool is_use)
{
pred_chain_union norm_preds = vNULL;
size_t n = preds.length ();
size_t i;
if (dump_file && dump_flags & TDF_DETAILS)
{
fprintf (dump_file, "[BEFORE NORMALIZATION --");
dump_predicates (use_or_def, preds, is_use ? "[USE]:\n" : "[DEF]:\n");
}
for (i = 0; i < n; i++)
{
if (preds[i].length () != 1)
normalize_one_pred_chain (&norm_preds, preds[i]);
else
{
normalize_one_pred (&norm_preds, preds[i][0]);
preds[i].release ();
}
}
if (dump_file)
{
fprintf (dump_file, "[AFTER NORMALIZATION -- ");
dump_predicates (use_or_def, norm_preds, is_use ? "[USE]:\n" : "[DEF]:\n");
}
preds.release ();
return norm_preds;
}
/* Computes the predicates that guard the use and checks
......@@ -1917,12 +2103,11 @@ is_use_properly_guarded (gimple use_stmt,
basic_block use_bb,
gimple phi,
unsigned uninit_opnds,
struct pointer_set_t *visited_phis)
pointer_set_t *visited_phis)
{
basic_block phi_bb;
vec<use_pred_info_t> *preds = 0;
vec<use_pred_info_t> *def_preds = 0;
size_t num_preds = 0, num_def_preds = 0;
pred_chain_union preds = vNULL;
pred_chain_union def_preds = vNULL;
bool has_valid_preds = false;
bool is_properly_guarded = false;
......@@ -1934,49 +2119,44 @@ is_use_properly_guarded (gimple use_stmt,
if (is_non_loop_exit_postdominating (use_bb, phi_bb))
return false;
has_valid_preds = find_predicates (&preds, &num_preds,
phi_bb, use_bb);
has_valid_preds = find_predicates (&preds, phi_bb, use_bb);
if (!has_valid_preds)
{
destroy_predicate_vecs (num_preds, preds);
destroy_predicate_vecs (preds);
return false;
}
if (dump_file)
dump_predicates (use_stmt, num_preds, preds,
"\nUse in stmt ");
has_valid_preds = find_def_preds (&def_preds,
&num_def_preds, phi);
/* Try to prune the dead incoming phi edges. */
is_properly_guarded
= use_pred_not_overlap_with_undef_path_pred (preds, phi, uninit_opnds,
visited_phis);
if (has_valid_preds)
if (is_properly_guarded)
{
bool normed;
if (dump_file)
dump_predicates (phi, num_def_preds, def_preds,
"Operand defs of phi ");
destroy_predicate_vecs (preds);
return true;
}
normed = normalize_preds (def_preds, &num_def_preds);
if (normed && dump_file)
{
fprintf (dump_file, "\nNormalized to\n");
dump_predicates (phi, num_def_preds, def_preds,
"Operand defs of phi ");
}
is_properly_guarded =
is_superset_of (def_preds, num_def_preds,
preds, num_preds);
has_valid_preds = find_def_preds (&def_preds, phi);
if (!has_valid_preds)
{
destroy_predicate_vecs (preds);
destroy_predicate_vecs (def_preds);
return false;
}
/* further prune the dead incoming phi edges. */
if (!is_properly_guarded)
is_properly_guarded
= use_pred_not_overlap_with_undef_path_pred (
num_preds, preds, phi, uninit_opnds, visited_phis);
simplify_preds (&preds, use_stmt, true);
preds = normalize_preds (preds, use_stmt, true);
simplify_preds (&def_preds, phi, false);
def_preds = normalize_preds (def_preds, phi, false);
is_properly_guarded = is_superset_of (def_preds, preds);
destroy_predicate_vecs (num_preds, preds);
destroy_predicate_vecs (num_def_preds, def_preds);
destroy_predicate_vecs (preds);
destroy_predicate_vecs (def_preds);
return is_properly_guarded;
}
......@@ -1992,7 +2172,7 @@ is_use_properly_guarded (gimple use_stmt,
static gimple
find_uninit_use (gimple phi, unsigned uninit_opnds,
vec<gimple> *worklist,
struct pointer_set_t *added_to_worklist)
pointer_set_t *added_to_worklist)
{
tree phi_result;
use_operand_p use_p;
......@@ -2003,7 +2183,7 @@ find_uninit_use (gimple phi, unsigned uninit_opnds,
FOR_EACH_IMM_USE_FAST (use_p, iter, phi_result)
{
struct pointer_set_t *visited_phis;
pointer_set_t *visited_phis;
basic_block use_bb;
use_stmt = USE_STMT (use_p);
......@@ -2018,10 +2198,7 @@ find_uninit_use (gimple phi, unsigned uninit_opnds,
else
use_bb = gimple_bb (use_stmt);
if (is_use_properly_guarded (use_stmt,
use_bb,
phi,
uninit_opnds,
if (is_use_properly_guarded (use_stmt, use_bb, phi, uninit_opnds,
visited_phis))
{
pointer_set_destroy (visited_phis);
......@@ -2040,8 +2217,7 @@ find_uninit_use (gimple phi, unsigned uninit_opnds,
/* Found a phi use that is not guarded,
add the phi to the worklist. */
if (!pointer_set_insert (added_to_worklist,
use_stmt))
if (!pointer_set_insert (added_to_worklist, use_stmt))
{
if (dump_file && (dump_flags & TDF_DETAILS))
{
......@@ -2067,7 +2243,7 @@ find_uninit_use (gimple phi, unsigned uninit_opnds,
static void
warn_uninitialized_phi (gimple phi, vec<gimple> *worklist,
struct pointer_set_t *added_to_worklist)
pointer_set_t *added_to_worklist)
{
unsigned uninit_opnds;
gimple uninit_use_stmt = 0;
......@@ -2115,7 +2291,7 @@ execute_late_warn_uninitialized (void)
basic_block bb;
gimple_stmt_iterator gsi;
vec<gimple> worklist = vNULL;
struct pointer_set_t *added_to_worklist;
pointer_set_t *added_to_worklist;
calculate_dominance_info (CDI_DOMINATORS);
calculate_dominance_info (CDI_POST_DOMINATORS);
......@@ -2229,8 +2405,7 @@ execute_early_warn_uninitialized (void)
execute_late_warn_uninitialized only runs with optimization. With
optimization we want to warn about possible uninitialized as late
as possible, thus don't do it here. However, without
optimization we need to warn here about "may be uninitialized".
*/
optimization we need to warn here about "may be uninitialized". */
calculate_dominance_info (CDI_POST_DOMINATORS);
warn_uninitialized_vars (/*warn_possibly_uninitialized=*/!optimize);
......@@ -2280,5 +2455,3 @@ make_pass_early_warn_uninitialized (gcc::context *ctxt)
{
return new pass_early_warn_uninitialized (ctxt);
}
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment