#define HAVE_tablejump 0
#endif
+/* Return true if a switch should be expanded as a bit test.
+ INDEX_EXPR is the index expression, RANGE is the difference between
+ highest and lowest case, UNIQ is number of unique case node targets
+ not counting the default case and COUNT is the number of comparisons
+ needed, not counting the default case. */
+bool
+expand_switch_using_bit_tests_p (tree index_expr, tree range,
+ unsigned int uniq, unsigned int count)
+{
+ return (CASE_USE_BIT_TESTS
+ && ! TREE_CONSTANT (index_expr)
+ && compare_tree_int (range, GET_MODE_BITSIZE (word_mode)) < 0
+ && compare_tree_int (range, 0) > 0
+ && lshift_cheap_p ()
+ && ((uniq == 1 && count >= 3)
+ || (uniq == 2 && count >= 5)
+ || (uniq == 3 && count >= 6)));
+}
+
/* Terminate a case (Pascal/Ada) or switch (C) statement
in which ORIG_INDEX is the expression to be tested.
If ORIG_TYPE is not NULL, it is the original ORIG_INDEX
/* Try implementing this switch statement by a short sequence of
bit-wise comparisons. However, we let the binary-tree case
below handle constant index expressions. */
- if (CASE_USE_BIT_TESTS
- && ! TREE_CONSTANT (index_expr)
- && compare_tree_int (range, GET_MODE_BITSIZE (word_mode)) < 0
- && compare_tree_int (range, 0) > 0
- && lshift_cheap_p ()
- && ((uniq == 1 && count >= 3)
- || (uniq == 2 && count >= 5)
- || (uniq == 3 && count >= 6)))
+ if (expand_switch_using_bit_tests_p (index_expr, range, uniq, count))
{
/* Optimize the case where all the case values fit in a
word without having to subtract MINVAL. In this case,
/* String reason why the case wasn't a good candidate that is written to the
dump file, if there is one. */
const char *reason;
+
+ /* Parameters for expand_switch_using_bit_tests. Should be computed
+ the same way as in expand_case. */
+ unsigned int bit_test_uniq;
+ unsigned int bit_test_count;
+ basic_block bit_test_bb[2];
};
/* Global pass info. */
tree range_max;
/* The gimplifier has already sorted the cases by CASE_LOW and ensured there
- is a default label which is the last in the vector. */
+ is a default label which is the first in the vector. */
min_case = gimple_switch_label (swtch, 1);
info.range_min = CASE_LOW (min_case);
info.default_count = e->count;
}
else
- info.other_count += e->count;
+ {
+ int i;
+ info.other_count += e->count;
+ for (i = 0; i < 2; i++)
+ if (info.bit_test_bb[i] == label_bb)
+ break;
+ else if (info.bit_test_bb[i] == NULL)
+ {
+ info.bit_test_bb[i] = label_bb;
+ info.bit_test_uniq++;
+ break;
+ }
+ if (i == 2)
+ info.bit_test_uniq = 3;
+ if (CASE_HIGH (cs) != NULL_TREE
+ && ! tree_int_cst_equal (CASE_LOW (cs), CASE_HIGH (cs)))
+ info.bit_test_count += 2;
+ else
+ info.bit_test_count++;
+ }
if (!label_bb)
{
{
int i;
- info.default_values = (tree *) xcalloc (info.phi_count, sizeof (tree));
- info.constructors = (VEC (constructor_elt, gc) **) xcalloc (info.phi_count,
- sizeof (tree));
- info.target_inbound_names = (tree *) xcalloc (info.phi_count, sizeof (tree));
- info.target_outbound_names = (tree *) xcalloc (info.phi_count,
- sizeof (tree));
-
+ info.default_values = XCNEWVEC (tree, info.phi_count * 3);
+ info.constructors = XCNEWVEC (VEC (constructor_elt, gc) *, info.phi_count);
+ info.target_inbound_names = info.default_values + info.phi_count;
+ info.target_outbound_names = info.target_inbound_names + info.phi_count;
for (i = 0; i < info.phi_count; i++)
info.constructors[i]
= VEC_alloc (constructor_elt, gc, tree_low_cst (info.range_size, 1) + 1);
static void
free_temp_arrays (void)
{
- free (info.constructors);
- free (info.default_values);
- free (info.target_inbound_names);
- free (info.target_outbound_names);
+ XDELETEVEC (info.constructors);
+ XDELETEVEC (info.default_values);
}
/* Populate the array of default values in the order of phi nodes.
static tree
constructor_contains_same_values_p (VEC (constructor_elt, gc) *vec)
{
- int i, len = VEC_length (constructor_elt, vec);
+ unsigned int i;
tree prev = NULL_TREE;
+ constructor_elt *elt;
- for (i = 0; i < len; i++)
+ FOR_EACH_VEC_ELT (constructor_elt, vec, i, elt)
{
- constructor_elt *elt = VEC_index (constructor_elt, vec, i);
-
if (!prev)
prev = elt->value;
else if (!operand_equal_p (elt->value, prev, OEP_ONLY_CONST))
return prev;
}
+/* Return type which should be used for array elements, either TYPE,
+ or for integral type some smaller integral type that can still hold
+ all the constants. */
+
+static tree
+array_value_type (gimple swtch, tree type, int num)
+{
+ unsigned int i, len = VEC_length (constructor_elt, info.constructors[num]);
+ constructor_elt *elt;
+ enum machine_mode mode;
+ int sign = 0;
+ tree smaller_type;
+
+ if (!INTEGRAL_TYPE_P (type))
+ return type;
+
+ mode = GET_CLASS_NARROWEST_MODE (GET_MODE_CLASS (TYPE_MODE (type)));
+ if (GET_MODE_SIZE (TYPE_MODE (type)) <= GET_MODE_SIZE (mode))
+ return type;
+
+ if (len < (optimize_bb_for_size_p (gimple_bb (swtch)) ? 2 : 32))
+ return type;
+
+ FOR_EACH_VEC_ELT (constructor_elt, info.constructors[num], i, elt)
+ {
+ double_int cst;
+
+ if (TREE_CODE (elt->value) != INTEGER_CST)
+ return type;
+
+ cst = TREE_INT_CST (elt->value);
+ while (1)
+ {
+ unsigned int prec = GET_MODE_BITSIZE (mode);
+ if (prec > HOST_BITS_PER_WIDE_INT)
+ return type;
+
+ if (sign >= 0
+ && double_int_equal_p (cst, double_int_zext (cst, prec)))
+ {
+ if (sign == 0
+ && double_int_equal_p (cst, double_int_sext (cst, prec)))
+ break;
+ sign = 1;
+ break;
+ }
+ if (sign <= 0
+ && double_int_equal_p (cst, double_int_sext (cst, prec)))
+ {
+ sign = -1;
+ break;
+ }
+
+ if (sign == 1)
+ sign = 0;
+
+ mode = GET_MODE_WIDER_MODE (mode);
+ if (mode == VOIDmode
+ || GET_MODE_SIZE (mode) >= GET_MODE_SIZE (TYPE_MODE (type)))
+ return type;
+ }
+ }
+
+ if (sign == 0)
+ sign = TYPE_UNSIGNED (type) ? 1 : -1;
+ smaller_type = lang_hooks.types.type_for_mode (mode, sign >= 0);
+ if (GET_MODE_SIZE (TYPE_MODE (type))
+ <= GET_MODE_SIZE (TYPE_MODE (smaller_type)))
+ return type;
+
+ return smaller_type;
+}
+
/* Create an appropriate array type and declaration and assemble a static array
variable. Also create a load statement that initializes the variable in
question with a value from the static array. SWTCH is the switch statement
load = gimple_build_assign (name, cst);
else
{
- tree array_type, ctor, decl, value_type, fetch;
+ tree array_type, ctor, decl, value_type, fetch, default_type;
- value_type = TREE_TYPE (info.default_values[num]);
+ default_type = TREE_TYPE (info.default_values[num]);
+ value_type = array_value_type (swtch, default_type, num);
array_type = build_array_type (value_type, arr_index_type);
+ if (default_type != value_type)
+ {
+ unsigned int i;
+ constructor_elt *elt;
+
+ FOR_EACH_VEC_ELT (constructor_elt, info.constructors[num], i, elt)
+ elt->value = fold_convert (value_type, elt->value);
+ }
ctor = build_constructor (array_type, info.constructors[num]);
TREE_CONSTANT (ctor) = true;
TREE_STATIC (ctor) = true;
fetch = build4 (ARRAY_REF, value_type, decl, tidx, NULL_TREE,
NULL_TREE);
+ if (default_type != value_type)
+ {
+ fetch = fold_convert (default_type, fetch);
+ fetch = force_gimple_operand_gsi (&gsi, fetch, true, NULL_TREE,
+ true, GSI_SAME_STMT);
+ }
load = gimple_build_assign (name, fetch);
}
info.default_prob = 0;
info.default_count = 0;
info.other_count = 0;
+ info.bit_test_uniq = 0;
+ info.bit_test_count = 0;
+ info.bit_test_bb[0] = NULL;
+ info.bit_test_bb[1] = NULL;
/* An ERROR_MARK occurs for various reasons including invalid data type.
(comment from stmt.c) */
return false;
}
+ if (info.bit_test_uniq <= 2)
+ {
+ rtl_profile_for_bb (gimple_bb (swtch));
+ if (expand_switch_using_bit_tests_p (gimple_switch_index (swtch),
+ info.range_size, info.bit_test_uniq,
+ info.bit_test_count))
+ {
+ info.reason = " Expanding as bit test is preferable\n";
+ return false;
+ }
+ }
+
if (!check_final_bb ())
return false;
projects / thirdparty / gcc.git / commitdiff
