basic block INSTANTIATED_BELOW, the value of VAR can be expressed
as CHREC. */
-struct scev_info_str GTY(())
-{
+struct GTY(()) scev_info_str {
basic_block instantiated_below;
tree var;
tree chrec;
EVOLUTION_FN = {i_0, +, 2}_1.
*/
-static tree
+tree
compute_overall_effect_of_inner_loop (struct loop *loop, tree evolution_fn)
{
bool val = false;
/* evolution_fn is the evolution function in LOOP. Get
its value in the nb_iter-th iteration. */
res = chrec_apply (inner_loop->num, evolution_fn, nb_iter);
-
+
+ if (chrec_contains_symbols_defined_in_loop (res, loop->num))
+ res = instantiate_parameters (loop, res);
+
/* Continue the computation until ending on a parent of LOOP. */
return compute_overall_effect_of_inner_loop (loop, res);
}
follow_ssa_edge_expr (struct loop *loop, gimple at_stmt, tree expr,
gimple halting_phi, tree *evolution_of_loop, int limit)
{
- t_bool res = t_false;
- tree rhs0, rhs1;
- tree type = TREE_TYPE (expr);
- enum tree_code code;
-
+ enum tree_code code = TREE_CODE (expr);
+ tree type = TREE_TYPE (expr), rhs0, rhs1;
+ t_bool res;
+
/* The EXPR is one of the following cases:
- an SSA_NAME,
- an INTEGER_CST,
- a MINUS_EXPR,
- an ASSERT_EXPR,
- other cases are not yet handled. */
- code = TREE_CODE (expr);
+
switch (code)
{
- case NOP_EXPR:
+ CASE_CONVERT:
/* This assignment is under the form "a_1 = (cast) rhs. */
res = follow_ssa_edge_expr (loop, at_stmt, TREE_OPERAND (expr, 0),
halting_phi, evolution_of_loop, limit);
/* This assignment is under the form "a_1 = 7". */
res = t_false;
break;
-
+
case SSA_NAME:
/* This assignment is under the form: "a_1 = b_2". */
res = follow_ssa_edge
(loop, SSA_NAME_DEF_STMT (expr), halting_phi, evolution_of_loop, limit);
break;
-
+
case POINTER_PLUS_EXPR:
case PLUS_EXPR:
case MINUS_EXPR:
/* This case is under the form "rhs0 +- rhs1". */
rhs0 = TREE_OPERAND (expr, 0);
rhs1 = TREE_OPERAND (expr, 1);
- STRIP_TYPE_NOPS (rhs0);
- STRIP_TYPE_NOPS (rhs1);
- return follow_ssa_edge_binary (loop, at_stmt, type, rhs0, code, rhs1,
- halting_phi, evolution_of_loop, limit);
+ type = TREE_TYPE (rhs0);
+ STRIP_USELESS_TYPE_CONVERSION (rhs0);
+ STRIP_USELESS_TYPE_CONVERSION (rhs1);
+ res = follow_ssa_edge_binary (loop, at_stmt, type, rhs0, code, rhs1,
+ halting_phi, evolution_of_loop, limit);
+ break;
case ASSERT_EXPR:
- {
- /* This assignment is of the form: "a_1 = ASSERT_EXPR <a_2, ...>"
- It must be handled as a copy assignment of the form a_1 = a_2. */
- tree op0 = ASSERT_EXPR_VAR (expr);
- if (TREE_CODE (op0) == SSA_NAME)
- res = follow_ssa_edge (loop, SSA_NAME_DEF_STMT (op0),
- halting_phi, evolution_of_loop, limit);
- else
- res = t_false;
- break;
- }
-
+ /* This assignment is of the form: "a_1 = ASSERT_EXPR <a_2, ...>"
+ It must be handled as a copy assignment of the form a_1 = a_2. */
+ rhs0 = ASSERT_EXPR_VAR (expr);
+ if (TREE_CODE (rhs0) == SSA_NAME)
+ res = follow_ssa_edge (loop, SSA_NAME_DEF_STMT (rhs0),
+ halting_phi, evolution_of_loop, limit);
+ else
+ res = t_false;
+ break;
default:
res = t_false;
break;
}
-
+
return res;
}
follow_ssa_edge_in_rhs (struct loop *loop, gimple stmt,
gimple halting_phi, tree *evolution_of_loop, int limit)
{
- tree type = TREE_TYPE (gimple_assign_lhs (stmt));
enum tree_code code = gimple_assign_rhs_code (stmt);
+ tree type = gimple_expr_type (stmt), rhs1, rhs2;
+ t_bool res;
- switch (get_gimple_rhs_class (code))
+ switch (code)
{
- case GIMPLE_BINARY_RHS:
- return follow_ssa_edge_binary (loop, stmt, type,
- gimple_assign_rhs1 (stmt), code,
- gimple_assign_rhs2 (stmt),
- halting_phi, evolution_of_loop, limit);
- case GIMPLE_SINGLE_RHS:
- return follow_ssa_edge_expr (loop, stmt, gimple_assign_rhs1 (stmt),
- halting_phi, evolution_of_loop, limit);
- case GIMPLE_UNARY_RHS:
- if (code == NOP_EXPR)
- {
- /* This assignment is under the form "a_1 = (cast) rhs. */
- t_bool res
- = follow_ssa_edge_expr (loop, stmt, gimple_assign_rhs1 (stmt),
+ CASE_CONVERT:
+ /* This assignment is under the form "a_1 = (cast) rhs. */
+ res = follow_ssa_edge_expr (loop, stmt, gimple_assign_rhs1 (stmt),
+ halting_phi, evolution_of_loop, limit);
+ *evolution_of_loop = chrec_convert (type, *evolution_of_loop, stmt);
+ break;
+
+ case POINTER_PLUS_EXPR:
+ case PLUS_EXPR:
+ case MINUS_EXPR:
+ rhs1 = gimple_assign_rhs1 (stmt);
+ rhs2 = gimple_assign_rhs2 (stmt);
+ type = TREE_TYPE (rhs1);
+ res = follow_ssa_edge_binary (loop, stmt, type, rhs1, code, rhs2,
halting_phi, evolution_of_loop, limit);
- *evolution_of_loop = chrec_convert (type, *evolution_of_loop, stmt);
- return res;
- }
- /* FALLTHRU */
+ break;
default:
- return t_false;
+ if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS)
+ res = follow_ssa_edge_expr (loop, stmt, gimple_assign_rhs1 (stmt),
+ halting_phi, evolution_of_loop, limit);
+ else
+ res = t_false;
+ break;
}
+
+ return res;
}
/* Checks whether the I-th argument of a PHI comes from a backedge. */
*evolution_of_loop = evolution_of_branch;
- /* If the phi node is just a copy, do not increase the limit. */
n = gimple_phi_num_args (condition_phi);
- if (n > 1)
- limit++;
-
for (i = 1; i < n; i++)
{
/* Quickly give up when the evolution of one of the branches is
if (*evolution_of_loop == chrec_dont_know)
return t_true;
+ /* Increase the limit by the PHI argument number to avoid exponential
+ time and memory complexity. */
res = follow_ssa_edge_in_condition_phi_branch (i, loop, condition_phi,
halting_phi,
&evolution_of_branch,
- init, limit);
+ init, limit + i);
if (res == t_false || res == t_dont_know)
return res;
if (init_cond == chrec_not_analyzed_yet)
init_cond = chrec_dont_know;
+ /* During early loop unrolling we do not have fully constant propagated IL.
+ Handle degenerate PHIs here to not miss important unrollings. */
+ if (TREE_CODE (init_cond) == SSA_NAME)
+ {
+ gimple def = SSA_NAME_DEF_STMT (init_cond);
+ tree res;
+ if (gimple_code (def) == GIMPLE_PHI
+ && (res = degenerate_phi_result (def)) != NULL_TREE
+ /* Only allow invariants here, otherwise we may break
+ loop-closed SSA form. */
+ && is_gimple_min_invariant (res))
+ init_cond = res;
+ }
+
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, " (init_cond = ");
return res;
}
-/* Entry point for the scalar evolution analyzer.
- Analyzes and returns the scalar evolution of the ssa_name VAR.
- LOOP_NB is the identifier number of the loop in which the variable
- is used.
+/* Analyzes and returns the scalar evolution of the ssa_name VAR in
+ LOOP. LOOP is the loop in which the variable is used.
Example of use: having a pointer VAR to a SSA_NAME node, STMT a
pointer to the statement that uses this variable, in order to
determine the evolution function of the variable, use the following
calls:
- unsigned loop_nb = loop_containing_stmt (stmt)->num;
- tree chrec_with_symbols = analyze_scalar_evolution (loop_nb, var);
+ loop_p loop = loop_containing_stmt (stmt);
+ tree chrec_with_symbols = analyze_scalar_evolution (loop, var);
tree chrec_instantiated = instantiate_parameters (loop, chrec_with_symbols);
*/
else
res = chrec;
- if (res == NULL_TREE)
+ if (res == NULL_TREE
+ || !dominated_by_p (CDI_DOMINATORS, instantiate_below,
+ gimple_bb (SSA_NAME_DEF_STMT (res))))
res = chrec_dont_know;
}
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