/* List of basic blocks in if-conversion-suitable order. */
static basic_block *ifc_bbs;
+/* Structure used to predicate basic blocks. This is attached to the
+ ->aux field of the BBs in the loop to be if-converted. */
+typedef struct bb_predicate_s {
+
+ /* The condition under which this basic block is executed. */
+ tree predicate;
+
+ /* PREDICATE is gimplified, and the sequence of statements is
+ recorded here, in order to avoid the duplication of computations
+ that occur in previous conditions. See PR44483. */
+ gimple_seq predicate_gimplified_stmts;
+} *bb_predicate_p;
+
+/* Returns true when the basic block BB has a predicate. */
+
+static inline bool
+bb_has_predicate (basic_block bb)
+{
+ return bb->aux != NULL;
+}
+
+/* Returns the gimplified predicate for basic block BB. */
+
+static inline tree
+bb_predicate (basic_block bb)
+{
+ return ((bb_predicate_p) bb->aux)->predicate;
+}
+
+/* Sets the gimplified predicate COND for basic block BB. */
+
+static inline void
+set_bb_predicate (basic_block bb, tree cond)
+{
+ ((bb_predicate_p) bb->aux)->predicate = cond;
+}
+
+/* Returns the sequence of statements of the gimplification of the
+ predicate for basic block BB. */
+
+static inline gimple_seq
+bb_predicate_gimplified_stmts (basic_block bb)
+{
+ return ((bb_predicate_p) bb->aux)->predicate_gimplified_stmts;
+}
+
+/* Sets the sequence of statements STMTS of the gimplification of the
+ predicate for basic block BB. */
+
+static inline void
+set_bb_predicate_gimplified_stmts (basic_block bb, gimple_seq stmts)
+{
+ ((bb_predicate_p) bb->aux)->predicate_gimplified_stmts = stmts;
+}
+
+/* Adds the sequence of statements STMTS to the sequence of statements
+ of the predicate for basic block BB. */
+
+static inline void
+add_bb_predicate_gimplified_stmts (basic_block bb, gimple_seq stmts)
+{
+ gimple_seq_add_seq
+ (&(((bb_predicate_p) bb->aux)->predicate_gimplified_stmts), stmts);
+}
+
+/* Initializes to TRUE the predicate of basic block BB. */
+
+static inline void
+init_bb_predicate (basic_block bb)
+{
+ bb->aux = XNEW (struct bb_predicate_s);
+ set_bb_predicate_gimplified_stmts (bb, NULL);
+ set_bb_predicate (bb, NULL_TREE);
+}
+
+/* Free the predicate of basic block BB. */
+
+static inline void
+free_bb_predicate (basic_block bb)
+{
+ gimple_seq stmts;
+
+ if (!bb_has_predicate (bb))
+ return;
+
+ /* Release the SSA_NAMEs created for the gimplification of the
+ predicate. */
+ stmts = bb_predicate_gimplified_stmts (bb);
+ if (stmts)
+ {
+ gimple_stmt_iterator i;
+
+ for (i = gsi_start (stmts); !gsi_end_p (i); gsi_next (&i))
+ free_stmt_operands (gsi_stmt (i));
+ }
+
+ free (bb->aux);
+ bb->aux = NULL;
+}
+
/* Create a new temp variable of type TYPE. Add GIMPLE_ASSIGN to assign EXP
to the new variable. */
static inline bool
is_predicated (basic_block bb)
{
- return !is_true_predicate ((tree) bb->aux);
+ return !is_true_predicate (bb_predicate (bb));
}
/* Add condition NEW_COND to the predicate list of basic block BB. */
static inline void
add_to_predicate_list (basic_block bb, tree new_cond)
{
- tree cond = (tree) bb->aux;
+ tree cond = bb_predicate (bb);
- bb->aux = is_true_predicate (cond) ? new_cond :
- fold_build2_loc (EXPR_LOCATION (cond),
- TRUTH_OR_EXPR, boolean_type_node,
- cond, new_cond);
+ set_bb_predicate (bb, is_true_predicate (cond) ? new_cond :
+ fold_build2_loc (EXPR_LOCATION (cond),
+ TRUTH_OR_EXPR, boolean_type_node,
+ cond, new_cond));
}
/* Add the condition COND to the previous condition PREV_COND, and add
/* Returns true when the analysis of the predicates for all the basic
blocks in LOOP succeeded.
- predicate_bbs first clears the ->aux fields of the basic blocks.
+ predicate_bbs first allocates the predicates of the basic blocks.
These fields are then initialized with the tree expressions
representing the predicates under which a basic block is executed
in the LOOP. As the loop->header is executed at each iteration, it
unsigned int i;
for (i = 0; i < loop->num_nodes; i++)
- ifc_bbs[i]->aux = NULL;
+ init_bb_predicate (ifc_bbs[i]);
for (i = 0; i < loop->num_nodes; i++)
{
- basic_block bb = ifc_bbs [i];
- tree cond = (tree) bb->aux;
+ basic_block bb = ifc_bbs[i];
+ tree cond;
gimple_stmt_iterator itr;
+ /* The loop latch is always executed and has no extra conditions
+ to be processed: skip it. */
+ if (bb == loop->latch)
+ {
+ set_bb_predicate (loop->latch, boolean_true_node);
+ set_bb_predicate_gimplified_stmts (loop->latch, NULL);
+ continue;
+ }
+
+ cond = bb_predicate (bb);
+ if (cond
+ && bb != loop->header)
+ {
+ gimple_seq stmts;
+
+ cond = force_gimple_operand (cond, &stmts, true, NULL_TREE);
+ add_bb_predicate_gimplified_stmts (bb, stmts);
+ }
+
for (itr = gsi_start_bb (bb); !gsi_end_p (itr); gsi_next (&itr))
{
gimple stmt = gsi_stmt (itr);
gimple_cond_lhs (stmt),
gimple_cond_rhs (stmt));
+ /* Add new condition into destination's predicate list. */
extract_true_false_edges_from_block (gimple_bb (stmt),
&true_edge, &false_edge);
- /* Add new condition into destination's predicate list. */
-
/* If C is true, then TRUE_EDGE is taken. */
add_to_dst_predicate_list (loop, true_edge, cond, c);
}
/* The loop header is always executed. */
- loop->header->aux = boolean_true_node;
+ set_bb_predicate (loop->header, boolean_true_node);
+ gcc_assert (bb_predicate_gimplified_stmts (loop->header) == NULL
+ && bb_predicate_gimplified_stmts (loop->latch) == NULL);
return true;
}
return true;
}
-/* During if-conversion, the bb->aux field is used to hold a predicate
- list. This function cleans for all the basic blocks in the given
- LOOP their predicate list. */
-
-static void
-clean_predicate_lists (struct loop *loop)
-{
- unsigned int i;
- basic_block *bbs = get_loop_body (loop);
-
- for (i = 0; i < loop->num_nodes; i++)
- bbs[i]->aux = NULL;
-
- free (bbs);
-}
-
-/* Basic block BB has two predecessors. Using predecessor's bb->aux
- field, set appropriate condition COND for the PHI node replacement.
- Return true block whose phi arguments are selected when cond is
- true. LOOP is the loop containing the if-converted region, GSI is
- the place to insert the code for the if-conversion. */
+/* Basic block BB has two predecessors. Using predecessor's bb
+ predicate, set an appropriate condition COND for the PHI node
+ replacement. Return the true block whose phi arguments are
+ selected when cond is true. LOOP is the loop containing the
+ if-converted region, GSI is the place to insert the code for the
+ if-conversion. */
static basic_block
find_phi_replacement_condition (struct loop *loop,
See PR23115. */
/* Select condition that is not TRUTH_NOT_EXPR. */
- tmp_cond = (tree) (first_edge->src)->aux;
+ tmp_cond = bb_predicate (first_edge->src);
gcc_assert (tmp_cond);
if (TREE_CODE (tmp_cond) == TRUTH_NOT_EXPR)
|| dominated_by_p (CDI_DOMINATORS,
second_edge->src, first_edge->src))
{
- *cond = (tree) (second_edge->src)->aux;
+ *cond = bb_predicate (second_edge->src);
if (TREE_CODE (*cond) == TRUTH_NOT_EXPR)
*cond = invert_truthvalue (*cond);
first_edge = second_edge;
}
else
- *cond = (tree) (first_edge->src)->aux;
+ *cond = bb_predicate (first_edge->src);
/* Gimplify the condition: the vectorizer prefers to have gimple
values as conditions. Various targets use different means to
}
}
-/* Process phi nodes for the given LOOP. Replace phi nodes with
- conditional modify expressions. */
+/* Replaces in LOOP all the phi nodes other than those in the
+ LOOP->header block with conditional modify expressions. */
static void
-process_phi_nodes (struct loop *loop)
+ifconvert_phi_nodes (struct loop *loop)
{
basic_block bb;
unsigned int orig_loop_num_nodes = loop->num_nodes;
continue;
phi_gsi = gsi_start_phis (bb);
- gsi = gsi_after_labels (bb);
+ if (gsi_end_p (phi_gsi))
+ continue;
/* BB has two predecessors. Using predecessor's aux field, set
appropriate condition for the PHI node replacement. */
- if (!gsi_end_p (phi_gsi))
- true_bb = find_phi_replacement_condition (loop, bb, &cond, &gsi);
+ gsi = gsi_after_labels (bb);
+ true_bb = find_phi_replacement_condition (loop, bb, &cond, &gsi);
while (!gsi_end_p (phi_gsi))
{
release_phi_node (phi);
gsi_next (&phi_gsi);
}
+
set_phi_nodes (bb, NULL);
}
}
+/* Insert in each basic block of LOOP the statements produced by the
+ gimplification of the predicates. */
+
+static void
+insert_gimplified_predicates (loop_p loop)
+{
+ unsigned int i;
+
+ for (i = 0; i < loop->num_nodes; i++)
+ {
+ basic_block bb = ifc_bbs[i];
+ gimple_seq stmts = bb_predicate_gimplified_stmts (bb);
+
+ if (stmts)
+ {
+ gimple_stmt_iterator gsi = gsi_last_bb (bb);
+
+ if (gsi_end_p (gsi)
+ || gimple_code (gsi_stmt (gsi)) == GIMPLE_COND)
+ gsi_insert_seq_before (&gsi, stmts, GSI_SAME_STMT);
+ else
+ gsi_insert_seq_after (&gsi, stmts, GSI_SAME_STMT);
+
+ /* Once the sequence is code generated, set it to NULL. */
+ set_bb_predicate_gimplified_stmts (bb, NULL);
+ }
+ }
+}
+
/* Remove all GIMPLE_CONDs and GIMPLE_LABELs of all the basic blocks
other than the exit and latch of the LOOP. Also resets the
GIMPLE_DEBUG information. */
for (i = 0; i < loop->num_nodes; i++)
{
- basic_block bb = ifc_bbs [i];
+ basic_block bb = ifc_bbs[i];
if (bb_with_exit_edge_p (loop, bb)
|| bb == loop->latch)
edge_iterator ei;
remove_conditions_and_labels (loop);
-
- /* Process phi nodes to prepare blocks for merge. */
- process_phi_nodes (loop);
+ insert_gimplified_predicates (loop);
+ ifconvert_phi_nodes (loop);
/* Merge basic blocks: first remove all the edges in the loop,
except for those from the exit block. */
combine_blocks (loop);
cleanup:
- clean_predicate_lists (loop);
if (ifc_bbs)
{
+ unsigned int i;
+
+ for (i = 0; i < loop->num_nodes; i++)
+ free_bb_predicate (ifc_bbs[i]);
+
free (ifc_bbs);
ifc_bbs = NULL;
}
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