if (CHREC_VARIABLE (evolution_fn) >= (unsigned) loop->num)
{
struct loop *inner_loop = get_chrec_loop (evolution_fn);
- tree nb_iter = number_of_iterations_in_loop (inner_loop);
+ tree nb_iter = number_of_latch_executions (inner_loop);
if (nb_iter == chrec_dont_know)
return chrec_dont_know;
else
{
tree res;
- tree type = chrec_type (nb_iter);
- /* Number of iterations is off by one (the ssa name we
- analyze must be defined before the exit). */
- nb_iter = chrec_fold_minus (type, nb_iter,
- build_int_cst (type, 1));
-
/* 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);
chrec_is_positive (tree chrec, bool *value)
{
bool value0, value1, value2;
- tree type, end_value, nb_iter;
+ tree end_value, nb_iter;
switch (TREE_CODE (chrec))
{
if (!evolution_function_is_affine_p (chrec))
return false;
- nb_iter = number_of_iterations_in_loop (get_chrec_loop (chrec));
+ nb_iter = number_of_latch_executions (get_chrec_loop (chrec));
if (chrec_contains_undetermined (nb_iter))
return false;
- type = chrec_type (nb_iter);
- nb_iter = chrec_fold_minus (type, nb_iter, build_int_cst (type, 1));
-
#if 0
/* TODO -- If the test is after the exit, we may decrease the number of
iterations by one. */
set_nb_iterations_in_loop (struct loop *loop,
tree res)
{
- tree type = chrec_type (res);
-
- res = chrec_fold_plus (type, res, build_int_cst (type, 1));
-
- /* FIXME HWI: However we want to store one iteration less than the
- count of the loop in order to be compatible with the other
- nb_iter computations in loop-iv. This also allows the
- representation of nb_iters that are equal to MAX_INT. */
- if (TREE_CODE (res) == INTEGER_CST
- && (TREE_INT_CST_LOW (res) == 0
- || TREE_OVERFLOW (res)))
- res = chrec_dont_know;
-
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, " (set_nb_iterations_in_loop = ");
the loop body has been executed 6 times. */
tree
-number_of_iterations_in_loop (struct loop *loop)
+number_of_latch_executions (struct loop *loop)
{
tree res, type;
edge exit;
return set_nb_iterations_in_loop (loop, res);
}
+/* Returns the number of executions of the exit condition of LOOP,
+ i.e., the number by one higher than number_of_latch_executions.
+ Note that unline number_of_latch_executions, this number does
+ not necessarily fit in the unsigned variant of the type of
+ the control variable -- if the number of iterations is a constant,
+ we return chrec_dont_know if adding one to number_of_latch_executions
+ overflows; however, in case the number of iterations is symbolic
+ expression, the caller is responsible for dealing with this
+ the possible overflow. */
+
+tree
+number_of_exit_cond_executions (struct loop *loop)
+{
+ tree ret = number_of_latch_executions (loop);
+ tree type = chrec_type (ret);
+
+ if (chrec_contains_undetermined (ret))
+ return ret;
+
+ ret = chrec_fold_plus (type, ret, build_int_cst (type, 1));
+ if (TREE_CODE (ret) == INTEGER_CST
+ && TREE_OVERFLOW (ret))
+ return chrec_dont_know;
+
+ return ret;
+}
+
/* One of the drivers for testing the scalar evolutions analysis.
This function computes the number of iterations for all the loops
from the EXIT_CONDITIONS array. */
for (i = 0; VEC_iterate (tree, *exit_conditions, i, cond); i++)
{
- tree res = number_of_iterations_in_loop (loop_containing_stmt (cond));
+ tree res = number_of_latch_executions (loop_containing_stmt (cond));
if (chrec_contains_undetermined (res))
nb_chrec_dont_know_loops++;
else
if (!exit)
continue;
- niter = number_of_iterations_in_loop (loop);
+ niter = number_of_latch_executions (loop);
if (niter == chrec_dont_know
/* If computing the number of iterations is expensive, it may be
better not to introduce computations involving it. */