+2007-04-06 Zdenek Dvorak <dvorakz@suse.cz>
+
+ * tree-ssa-loop-niter.c (idx_infer_loop_bounds): Add and use
+ argument "reliable".
+ (infer_loop_bounds_from_ref, infer_loop_bounds_from_array):
+ Add argument "reliable". Propagate it through calls.
+ (infer_loop_bounds_from_undefined): Derive number of iterations
+ estimates from references in blocks that do not dominate loop latch.
+ (gcov_type_to_double_int): New function.
+ (estimate_numbers_of_iterations_loop): Use gcov_type_to_double_int
+ and expected_loop_iterations_unbounded.
+ * cfgloopanal.c (expected_loop_iterations_unbounded): New function.
+ (expected_loop_iterations): Use expected_loop_iterations_unbounded.
+ * tree-data-ref.c (estimated_loop_iterations): Export.
+ (get_references_in_stmt): Fix -- do not return addresses of local
+ objects.
+ * cfgloop.h (expected_loop_iterations_unbounded,
+ estimated_loop_iterations): Declare.
+
2007-04-06 Andreas Tobler <a.tobler@schweiz.org>
* tree-sra.c (sra_build_elt_assignment): Initialize min/maxshift.
}
/* Determine information about number of iterations a LOOP from the index
- IDX of a data reference accessed in STMT. Callback for for_each_index. */
+ IDX of a data reference accessed in STMT. RELIABLE is true if STMT is
+ guaranteed to be executed in every iteration of LOOP. Callback for
+ for_each_index. */
struct ilb_data
{
struct loop *loop;
tree stmt;
+ bool reliable;
};
static bool
struct ilb_data *data = dta;
tree ev, init, step;
tree low, high, type, next;
- bool sign, upper = true;
+ bool sign, upper = data->reliable, at_end = false;
struct loop *loop = data->loop;
if (TREE_CODE (base) != ARRAY_REF)
do not really extend over their declared size. However, for arrays of
size greater than one, this is unlikely to be intended. */
if (array_at_struct_end_p (base))
- upper = false;
+ {
+ at_end = true;
+ upper = false;
+ }
ev = instantiate_parameters (loop, analyze_scalar_evolution (loop, *idx));
init = initial_condition (ev);
/* The array of length 1 at the end of a structure most likely extends
beyond its bounds. */
- if (!upper
+ if (at_end
&& operand_equal_p (low, high, 0))
return true;
}
/* Determine information about number of iterations a LOOP from the bounds
- of arrays in the data reference REF accessed in STMT. */
+ of arrays in the data reference REF accessed in STMT. RELIABLE is true if
+ STMT is guaranteed to be executed in every iteration of LOOP.*/
static void
-infer_loop_bounds_from_ref (struct loop *loop, tree stmt, tree ref)
+infer_loop_bounds_from_ref (struct loop *loop, tree stmt, tree ref,
+ bool reliable)
{
struct ilb_data data;
data.loop = loop;
data.stmt = stmt;
+ data.reliable = reliable;
for_each_index (&ref, idx_infer_loop_bounds, &data);
}
/* Determine information about number of iterations of a LOOP from the way
- arrays are used in STMT. */
+ arrays are used in STMT. RELIABLE is true if STMT is guaranteed to be
+ executed in every iteration of LOOP. */
static void
-infer_loop_bounds_from_array (struct loop *loop, tree stmt)
+infer_loop_bounds_from_array (struct loop *loop, tree stmt, bool reliable)
{
tree call;
/* For each memory access, analyze its access function
and record a bound on the loop iteration domain. */
if (REFERENCE_CLASS_P (op0))
- infer_loop_bounds_from_ref (loop, stmt, op0);
+ infer_loop_bounds_from_ref (loop, stmt, op0, reliable);
if (REFERENCE_CLASS_P (op1))
- infer_loop_bounds_from_ref (loop, stmt, op1);
+ infer_loop_bounds_from_ref (loop, stmt, op1, reliable);
}
FOR_EACH_CALL_EXPR_ARG (arg, iter, call)
if (REFERENCE_CLASS_P (arg))
- infer_loop_bounds_from_ref (loop, stmt, arg);
+ infer_loop_bounds_from_ref (loop, stmt, arg, reliable);
}
}
basic_block *bbs;
block_stmt_iterator bsi;
basic_block bb;
+ bool reliable;
bbs = get_loop_body (loop);
bb = bbs[i];
/* If BB is not executed in each iteration of the loop, we cannot
- use it to infer any information about # of iterations of the loop. */
- if (!dominated_by_p (CDI_DOMINATORS, loop->latch, bb))
- continue;
+ use the operations in it to infer reliable upper bound on the
+ # of iterations of the loop. However, we can use it as a guess. */
+ reliable = dominated_by_p (CDI_DOMINATORS, loop->latch, bb);
for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
{
tree stmt = bsi_stmt (bsi);
- infer_loop_bounds_from_array (loop, stmt);
- infer_loop_bounds_from_signedness (loop, stmt);
+ infer_loop_bounds_from_array (loop, stmt, reliable);
+
+ if (reliable)
+ infer_loop_bounds_from_signedness (loop, stmt);
}
}
free (bbs);
}
+/* Converts VAL to double_int. */
+
+static double_int
+gcov_type_to_double_int (gcov_type val)
+{
+ double_int ret;
+
+ ret.low = (unsigned HOST_WIDE_INT) val;
+ /* If HOST_BITS_PER_WIDE_INT == HOST_BITS_PER_WIDEST_INT, avoid shifting by
+ the size of type. */
+ val >>= HOST_BITS_PER_WIDE_INT - 1;
+ val >>= 1;
+ ret.high = (unsigned HOST_WIDE_INT) val;
+
+ return ret;
+}
+
/* Records estimates on numbers of iterations of LOOP. */
void
iterations. */
if (loop->header->count != 0)
{
- bound = uhwi_to_double_int (expected_loop_iterations (loop) + 1);
+ gcov_type nit = expected_loop_iterations_unbounded (loop) + 1;
+ bound = gcov_type_to_double_int (nit);
record_niter_bound (loop, bound, true, false);
}
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