#include "tree-cfgcleanup.h"
#include "gimplify.h"
#include "attribs.h"
+#include "selftest.h"
/* This file contains functions for building the Control Flow Graph (CFG)
for a function tree. */
/* Called for each element in the hash table (P) as we delete the
edge to cases hash table.
- Clear all the TREE_CHAINs to prevent problems with copying of
+ Clear all the CASE_CHAINs to prevent problems with copying of
SWITCH_EXPRs and structure sharing rules, then free the hash table
element. */
return true;
}
- if (lhs
- && gimple_call_ctrl_altering_p (stmt)
+ if (gimple_call_ctrl_altering_p (stmt)
&& gimple_call_noreturn_p (stmt)
- && TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (lhs))) == INTEGER_CST
- && !TREE_ADDRESSABLE (TREE_TYPE (lhs)))
+ && should_remove_lhs_p (lhs))
{
error ("LHS in noreturn call");
return true;
return false;
+ case BIT_INSERT_EXPR:
+ if (! useless_type_conversion_p (lhs_type, rhs1_type))
+ {
+ error ("type mismatch in BIT_INSERT_EXPR");
+ debug_generic_expr (lhs_type);
+ debug_generic_expr (rhs1_type);
+ return true;
+ }
+ if (! ((INTEGRAL_TYPE_P (rhs1_type)
+ && INTEGRAL_TYPE_P (rhs2_type))
+ || (VECTOR_TYPE_P (rhs1_type)
+ && types_compatible_p (TREE_TYPE (rhs1_type), rhs2_type))))
+ {
+ error ("not allowed type combination in BIT_INSERT_EXPR");
+ debug_generic_expr (rhs1_type);
+ debug_generic_expr (rhs2_type);
+ return true;
+ }
+ if (! tree_fits_uhwi_p (rhs3)
+ || ! tree_fits_uhwi_p (TYPE_SIZE (rhs2_type)))
+ {
+ error ("invalid position or size in BIT_INSERT_EXPR");
+ return true;
+ }
+ if (INTEGRAL_TYPE_P (rhs1_type))
+ {
+ unsigned HOST_WIDE_INT bitpos = tree_to_uhwi (rhs3);
+ if (bitpos >= TYPE_PRECISION (rhs1_type)
+ || (bitpos + TYPE_PRECISION (rhs2_type)
+ > TYPE_PRECISION (rhs1_type)))
+ {
+ error ("insertion out of range in BIT_INSERT_EXPR");
+ return true;
+ }
+ }
+ else if (VECTOR_TYPE_P (rhs1_type))
+ {
+ unsigned HOST_WIDE_INT bitpos = tree_to_uhwi (rhs3);
+ unsigned HOST_WIDE_INT bitsize = tree_to_uhwi (TYPE_SIZE (rhs2_type));
+ if (bitpos % bitsize != 0)
+ {
+ error ("vector insertion not at element boundary");
+ return true;
+ }
+ }
+ return false;
+
case DOT_PROD_EXPR:
case REALIGN_LOAD_EXPR:
/* FIXME. */
fprintf (file, ", upper_bound = ");
print_decu (loop->nb_iterations_upper_bound, file);
}
+ if (loop->any_likely_upper_bound)
+ {
+ fprintf (file, ", likely_upper_bound = ");
+ print_decu (loop->nb_iterations_likely_upper_bound, file);
+ }
if (loop->any_estimate)
{
}
-/* Return true if we need to add fake edge to exit at statement T.
- Helper function for gimple_flow_call_edges_add. */
+/* Return true if statement T may terminate execution of BB in ways not
+ explicitly represtented in the CFG. */
-static bool
-need_fake_edge_p (gimple *t)
+bool
+stmt_can_terminate_bb_p (gimple *t)
{
tree fndecl = NULL_TREE;
int call_flags = 0;
+ /* Eh exception not handled internally terminates execution of the whole
+ function. */
+ if (stmt_can_throw_external (t))
+ return true;
+
/* NORETURN and LONGJMP calls already have an edge to exit.
CONST and PURE calls do not need one.
We don't currently check for CONST and PURE here, although
edge e;
basic_block bb;
+ if (call_flags & (ECF_PURE | ECF_CONST)
+ && !(call_flags & ECF_LOOPING_CONST_OR_PURE))
+ return false;
+
+ /* Function call may do longjmp, terminate program or do other things.
+ Special case noreturn that have non-abnormal edges out as in this case
+ the fact is sufficiently represented by lack of edges out of T. */
if (!(call_flags & ECF_NORETURN))
return true;
if (!gsi_end_p (gsi))
t = gsi_stmt (gsi);
- if (t && need_fake_edge_p (t))
+ if (t && stmt_can_terminate_bb_p (t))
{
edge e;
do
{
stmt = gsi_stmt (gsi);
- if (need_fake_edge_p (stmt))
+ if (stmt_can_terminate_bb_p (stmt))
{
edge e;
op (&(e->insns.r), cookie);
op (&(block), cookie);
}
+
+#if CHECKING_P
+
+namespace selftest {
+
+/* Helper function for CFG selftests: create a dummy function decl
+ and push it as cfun. */
+
+static tree
+push_fndecl (const char *name)
+{
+ tree fn_type = build_function_type_array (integer_type_node, 0, NULL);
+ /* FIXME: this uses input_location: */
+ tree fndecl = build_fn_decl (name, fn_type);
+ tree retval = build_decl (UNKNOWN_LOCATION, RESULT_DECL,
+ NULL_TREE, integer_type_node);
+ DECL_RESULT (fndecl) = retval;
+ push_struct_function (fndecl);
+ function *fun = DECL_STRUCT_FUNCTION (fndecl);
+ ASSERT_TRUE (fun != NULL);
+ init_empty_tree_cfg_for_function (fun);
+ ASSERT_EQ (2, n_basic_blocks_for_fn (fun));
+ ASSERT_EQ (0, n_edges_for_fn (fun));
+ return fndecl;
+}
+
+/* These tests directly create CFGs.
+ Compare with the static fns within tree-cfg.c:
+ - build_gimple_cfg
+ - make_blocks: calls create_basic_block (seq, bb);
+ - make_edges. */
+
+/* Verify a simple cfg of the form:
+ ENTRY -> A -> B -> C -> EXIT. */
+
+static void
+test_linear_chain ()
+{
+ gimple_register_cfg_hooks ();
+
+ tree fndecl = push_fndecl ("cfg_test_linear_chain");
+ function *fun = DECL_STRUCT_FUNCTION (fndecl);
+
+ /* Create some empty blocks. */
+ basic_block bb_a = create_empty_bb (ENTRY_BLOCK_PTR_FOR_FN (fun));
+ basic_block bb_b = create_empty_bb (bb_a);
+ basic_block bb_c = create_empty_bb (bb_b);
+
+ ASSERT_EQ (5, n_basic_blocks_for_fn (fun));
+ ASSERT_EQ (0, n_edges_for_fn (fun));
+
+ /* Create some edges: a simple linear chain of BBs. */
+ make_edge (ENTRY_BLOCK_PTR_FOR_FN (fun), bb_a, EDGE_FALLTHRU);
+ make_edge (bb_a, bb_b, 0);
+ make_edge (bb_b, bb_c, 0);
+ make_edge (bb_c, EXIT_BLOCK_PTR_FOR_FN (fun), 0);
+
+ /* Verify the edges. */
+ ASSERT_EQ (4, n_edges_for_fn (fun));
+ ASSERT_EQ (NULL, ENTRY_BLOCK_PTR_FOR_FN (fun)->preds);
+ ASSERT_EQ (1, ENTRY_BLOCK_PTR_FOR_FN (fun)->succs->length ());
+ ASSERT_EQ (1, bb_a->preds->length ());
+ ASSERT_EQ (1, bb_a->succs->length ());
+ ASSERT_EQ (1, bb_b->preds->length ());
+ ASSERT_EQ (1, bb_b->succs->length ());
+ ASSERT_EQ (1, bb_c->preds->length ());
+ ASSERT_EQ (1, bb_c->succs->length ());
+ ASSERT_EQ (1, EXIT_BLOCK_PTR_FOR_FN (fun)->preds->length ());
+ ASSERT_EQ (NULL, EXIT_BLOCK_PTR_FOR_FN (fun)->succs);
+
+ /* Verify the dominance information
+ Each BB in our simple chain should be dominated by the one before
+ it. */
+ calculate_dominance_info (CDI_DOMINATORS);
+ ASSERT_EQ (bb_a, get_immediate_dominator (CDI_DOMINATORS, bb_b));
+ ASSERT_EQ (bb_b, get_immediate_dominator (CDI_DOMINATORS, bb_c));
+ vec<basic_block> dom_by_b = get_dominated_by (CDI_DOMINATORS, bb_b);
+ ASSERT_EQ (1, dom_by_b.length ());
+ ASSERT_EQ (bb_c, dom_by_b[0]);
+ free_dominance_info (CDI_DOMINATORS);
+ dom_by_b.release ();
+
+ /* Similarly for post-dominance: each BB in our chain is post-dominated
+ by the one after it. */
+ calculate_dominance_info (CDI_POST_DOMINATORS);
+ ASSERT_EQ (bb_b, get_immediate_dominator (CDI_POST_DOMINATORS, bb_a));
+ ASSERT_EQ (bb_c, get_immediate_dominator (CDI_POST_DOMINATORS, bb_b));
+ vec<basic_block> postdom_by_b = get_dominated_by (CDI_POST_DOMINATORS, bb_b);
+ ASSERT_EQ (1, postdom_by_b.length ());
+ ASSERT_EQ (bb_a, postdom_by_b[0]);
+ free_dominance_info (CDI_POST_DOMINATORS);
+ postdom_by_b.release ();
+
+ pop_cfun ();
+}
+
+/* Verify a simple CFG of the form:
+ ENTRY
+ |
+ A
+ / \
+ /t \f
+ B C
+ \ /
+ \ /
+ D
+ |
+ EXIT. */
+
+static void
+test_diamond ()
+{
+ gimple_register_cfg_hooks ();
+
+ tree fndecl = push_fndecl ("cfg_test_diamond");
+ function *fun = DECL_STRUCT_FUNCTION (fndecl);
+
+ /* Create some empty blocks. */
+ basic_block bb_a = create_empty_bb (ENTRY_BLOCK_PTR_FOR_FN (fun));
+ basic_block bb_b = create_empty_bb (bb_a);
+ basic_block bb_c = create_empty_bb (bb_a);
+ basic_block bb_d = create_empty_bb (bb_b);
+
+ ASSERT_EQ (6, n_basic_blocks_for_fn (fun));
+ ASSERT_EQ (0, n_edges_for_fn (fun));
+
+ /* Create the edges. */
+ make_edge (ENTRY_BLOCK_PTR_FOR_FN (fun), bb_a, EDGE_FALLTHRU);
+ make_edge (bb_a, bb_b, EDGE_TRUE_VALUE);
+ make_edge (bb_a, bb_c, EDGE_FALSE_VALUE);
+ make_edge (bb_b, bb_d, 0);
+ make_edge (bb_c, bb_d, 0);
+ make_edge (bb_d, EXIT_BLOCK_PTR_FOR_FN (fun), 0);
+
+ /* Verify the edges. */
+ ASSERT_EQ (6, n_edges_for_fn (fun));
+ ASSERT_EQ (1, bb_a->preds->length ());
+ ASSERT_EQ (2, bb_a->succs->length ());
+ ASSERT_EQ (1, bb_b->preds->length ());
+ ASSERT_EQ (1, bb_b->succs->length ());
+ ASSERT_EQ (1, bb_c->preds->length ());
+ ASSERT_EQ (1, bb_c->succs->length ());
+ ASSERT_EQ (2, bb_d->preds->length ());
+ ASSERT_EQ (1, bb_d->succs->length ());
+
+ /* Verify the dominance information. */
+ calculate_dominance_info (CDI_DOMINATORS);
+ ASSERT_EQ (bb_a, get_immediate_dominator (CDI_DOMINATORS, bb_b));
+ ASSERT_EQ (bb_a, get_immediate_dominator (CDI_DOMINATORS, bb_c));
+ ASSERT_EQ (bb_a, get_immediate_dominator (CDI_DOMINATORS, bb_d));
+ vec<basic_block> dom_by_a = get_dominated_by (CDI_DOMINATORS, bb_a);
+ ASSERT_EQ (3, dom_by_a.length ()); /* B, C, D, in some order. */
+ dom_by_a.release ();
+ vec<basic_block> dom_by_b = get_dominated_by (CDI_DOMINATORS, bb_b);
+ ASSERT_EQ (0, dom_by_b.length ());
+ dom_by_b.release ();
+ free_dominance_info (CDI_DOMINATORS);
+
+ /* Similarly for post-dominance. */
+ calculate_dominance_info (CDI_POST_DOMINATORS);
+ ASSERT_EQ (bb_d, get_immediate_dominator (CDI_POST_DOMINATORS, bb_a));
+ ASSERT_EQ (bb_d, get_immediate_dominator (CDI_POST_DOMINATORS, bb_b));
+ ASSERT_EQ (bb_d, get_immediate_dominator (CDI_POST_DOMINATORS, bb_c));
+ vec<basic_block> postdom_by_d = get_dominated_by (CDI_POST_DOMINATORS, bb_d);
+ ASSERT_EQ (3, postdom_by_d.length ()); /* A, B, C in some order. */
+ postdom_by_d.release ();
+ vec<basic_block> postdom_by_b = get_dominated_by (CDI_POST_DOMINATORS, bb_b);
+ ASSERT_EQ (0, postdom_by_b.length ());
+ postdom_by_b.release ();
+ free_dominance_info (CDI_POST_DOMINATORS);
+
+ pop_cfun ();
+}
+
+/* Verify that we can handle a CFG containing a "complete" aka
+ fully-connected subgraph (where A B C D below all have edges
+ pointing to each other node, also to themselves).
+ e.g.:
+ ENTRY EXIT
+ | ^
+ | /
+ | /
+ | /
+ V/
+ A<--->B
+ ^^ ^^
+ | \ / |
+ | X |
+ | / \ |
+ VV VV
+ C<--->D
+*/
+
+static void
+test_fully_connected ()
+{
+ gimple_register_cfg_hooks ();
+
+ tree fndecl = push_fndecl ("cfg_fully_connected");
+ function *fun = DECL_STRUCT_FUNCTION (fndecl);
+
+ const int n = 4;
+
+ /* Create some empty blocks. */
+ auto_vec <basic_block> subgraph_nodes;
+ for (int i = 0; i < n; i++)
+ subgraph_nodes.safe_push (create_empty_bb (ENTRY_BLOCK_PTR_FOR_FN (fun)));
+
+ ASSERT_EQ (n + 2, n_basic_blocks_for_fn (fun));
+ ASSERT_EQ (0, n_edges_for_fn (fun));
+
+ /* Create the edges. */
+ make_edge (ENTRY_BLOCK_PTR_FOR_FN (fun), subgraph_nodes[0], EDGE_FALLTHRU);
+ make_edge (subgraph_nodes[0], EXIT_BLOCK_PTR_FOR_FN (fun), 0);
+ for (int i = 0; i < n; i++)
+ for (int j = 0; j < n; j++)
+ make_edge (subgraph_nodes[i], subgraph_nodes[j], 0);
+
+ /* Verify the edges. */
+ ASSERT_EQ (2 + (n * n), n_edges_for_fn (fun));
+ /* The first one is linked to ENTRY/EXIT as well as itself and
+ everything else. */
+ ASSERT_EQ (n + 1, subgraph_nodes[0]->preds->length ());
+ ASSERT_EQ (n + 1, subgraph_nodes[0]->succs->length ());
+ /* The other ones in the subgraph are linked to everything in
+ the subgraph (including themselves). */
+ for (int i = 1; i < n; i++)
+ {
+ ASSERT_EQ (n, subgraph_nodes[i]->preds->length ());
+ ASSERT_EQ (n, subgraph_nodes[i]->succs->length ());
+ }
+
+ /* Verify the dominance information. */
+ calculate_dominance_info (CDI_DOMINATORS);
+ /* The initial block in the subgraph should be dominated by ENTRY. */
+ ASSERT_EQ (ENTRY_BLOCK_PTR_FOR_FN (fun),
+ get_immediate_dominator (CDI_DOMINATORS,
+ subgraph_nodes[0]));
+ /* Every other block in the subgraph should be dominated by the
+ initial block. */
+ for (int i = 1; i < n; i++)
+ ASSERT_EQ (subgraph_nodes[0],
+ get_immediate_dominator (CDI_DOMINATORS,
+ subgraph_nodes[i]));
+ free_dominance_info (CDI_DOMINATORS);
+
+ /* Similarly for post-dominance. */
+ calculate_dominance_info (CDI_POST_DOMINATORS);
+ /* The initial block in the subgraph should be postdominated by EXIT. */
+ ASSERT_EQ (EXIT_BLOCK_PTR_FOR_FN (fun),
+ get_immediate_dominator (CDI_POST_DOMINATORS,
+ subgraph_nodes[0]));
+ /* Every other block in the subgraph should be postdominated by the
+ initial block, since that leads to EXIT. */
+ for (int i = 1; i < n; i++)
+ ASSERT_EQ (subgraph_nodes[0],
+ get_immediate_dominator (CDI_POST_DOMINATORS,
+ subgraph_nodes[i]));
+ free_dominance_info (CDI_POST_DOMINATORS);
+
+ pop_cfun ();
+}
+
+/* Run all of the selftests within this file. */
+
+void
+tree_cfg_c_tests ()
+{
+ test_linear_chain ();
+ test_diamond ();
+ test_fully_connected ();
+}
+
+} // namespace selftest
+
+/* TODO: test the dominator/postdominator logic with various graphs/nodes:
+ - loop
+ - nested loops
+ - switch statement (a block with many out-edges)
+ - something that jumps to itself
+ - etc */
+
+#endif /* CHECKING_P */
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