static int node_has_high_bound (case_node_ptr, tree);
static int node_is_bounded (case_node_ptr, tree);
static void emit_case_nodes (rtx, case_node_ptr, rtx, tree);
-static struct case_node *add_case_node (struct case_node *, tree, tree, tree);
+static struct case_node *add_case_node (struct case_node *, tree,
+ tree, tree, tree);
\f
/* Return the rtx-label that corresponds to a LABEL_DECL,
or an ADDR_EXPR containing a STRING_CST. VOL nonzero means the
insn is volatile; don't optimize it. */
-void
+static void
expand_asm (tree string, int vol)
{
rtx body;
return true;
}
-/* INPUT is one of the input operands from EXPR, an ASM_EXPR. Returns true
- if it is an operand which must be passed in memory (i.e. an "m"
- constraint), false otherwise. */
-
-bool
-asm_op_is_mem_input (tree input, tree expr)
-{
- const char *constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (input)));
- tree outputs = ASM_OUTPUTS (expr);
- int noutputs = list_length (outputs);
- const char **constraints
- = (const char **) alloca ((noutputs) * sizeof (const char *));
- int i = 0;
- bool allows_mem, allows_reg;
- tree t;
-
- /* Collect output constraints. */
- for (t = outputs; t ; t = TREE_CHAIN (t), i++)
- constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
-
- /* We pass 0 for input_num, ninputs and ninout; they are only used for
- error checking which will be done at expand time. */
- parse_input_constraint (&constraint, 0, 0, noutputs, 0, constraints,
- &allows_mem, &allows_reg);
- return (!allows_reg && allows_mem);
-}
-
/* Check for overlap between registers marked in CLOBBERED_REGS and
anything inappropriate in DECL. Emit error and return TRUE for error,
FALSE for ok. */
VOL nonzero means the insn is volatile; don't optimize it. */
-void
+static void
expand_asm_operands (tree string, tree outputs, tree inputs,
tree clobbers, int vol, location_t locus)
{
/* Mark clobbered registers. */
if (i >= 0)
{
- /* Clobbering the PIC register is an error */
+ /* Clobbering the PIC register is an error. */
if (i == (int) PIC_OFFSET_TABLE_REGNUM)
{
error ("PIC register %qs clobbered in %<asm%>", regname);
{
if (o[i] != TREE_VALUE (tail))
{
- expand_assignment (o[i], TREE_VALUE (tail), 0);
+ expand_assignment (o[i], TREE_VALUE (tail));
free_temp_slots ();
/* Restore the original value so that it's correct the next
emit_stack_restore (SAVE_BLOCK, sa, NULL_RTX);
}
\f
-/* Emit code to perform the initialization of a declaration DECL. */
-
-void
-expand_decl_init (tree decl)
-{
- int was_used = TREE_USED (decl);
-
- /* If this is a CONST_DECL, we don't have to generate any code. Likewise
- for static decls. */
- if (TREE_CODE (decl) == CONST_DECL
- || TREE_STATIC (decl))
- return;
-
- /* Compute and store the initial value now. */
-
- push_temp_slots ();
-
- if (DECL_INITIAL (decl) == error_mark_node)
- {
- enum tree_code code = TREE_CODE (TREE_TYPE (decl));
-
- if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
- || code == POINTER_TYPE || code == REFERENCE_TYPE)
- expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
- 0);
- }
- else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
- {
- emit_line_note (DECL_SOURCE_LOCATION (decl));
- expand_assignment (decl, DECL_INITIAL (decl), 0);
- }
-
- /* Don't let the initialization count as "using" the variable. */
- TREE_USED (decl) = was_used;
-
- /* Free any temporaries we made while initializing the decl. */
- preserve_temp_slots (NULL_RTX);
- free_temp_slots ();
- pop_temp_slots ();
-}
-
-\f
/* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
DECL_ELTS is the list of elements that belong to DECL's type.
In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
/* Do the insertion of a case label into case_list. The labels are
fed to us in descending order from the sorted vector of case labels used
in the tree part of the middle end. So the list we construct is
- sorted in ascending order. */
+ sorted in ascending order. The bounds on the case range, LOW and HIGH,
+ are converted to case's index type TYPE. */
-struct case_node *
-add_case_node (struct case_node *head, tree low, tree high, tree label)
+static struct case_node *
+add_case_node (struct case_node *head, tree type, tree low, tree high,
+ tree label)
{
+ tree min_value, max_value;
struct case_node *r;
+ gcc_assert (TREE_CODE (low) == INTEGER_CST);
+ gcc_assert (!high || TREE_CODE (high) == INTEGER_CST);
+
+ min_value = TYPE_MIN_VALUE (type);
+ max_value = TYPE_MAX_VALUE (type);
+
/* If there's no HIGH value, then this is not a case range; it's
just a simple case label. But that's just a degenerate case
range.
If the bounds are equal, turn this into the one-value case. */
if (!high || tree_int_cst_equal (low, high))
- high = low;
+ {
+ /* If the simple case value is unreachable, ignore it. */
+ if ((TREE_CODE (min_value) == INTEGER_CST
+ && tree_int_cst_compare (low, min_value) < 0)
+ || (TREE_CODE (max_value) == INTEGER_CST
+ && tree_int_cst_compare (low, max_value) > 0))
+ return head;
+ low = fold_convert (type, low);
+ high = low;
+ }
+ else
+ {
+ /* If the entire case range is unreachable, ignore it. */
+ if ((TREE_CODE (min_value) == INTEGER_CST
+ && tree_int_cst_compare (high, min_value) < 0)
+ || (TREE_CODE (max_value) == INTEGER_CST
+ && tree_int_cst_compare (low, max_value) > 0))
+ return head;
+
+ /* If the lower bound is less than the index type's minimum
+ value, truncate the range bounds. */
+ if (TREE_CODE (min_value) == INTEGER_CST
+ && tree_int_cst_compare (low, min_value) < 0)
+ low = min_value;
+ low = fold_convert (type, low);
+
+ /* If the upper bound is greater than the index type's maximum
+ value, truncate the range bounds. */
+ if (TREE_CODE (max_value) == INTEGER_CST
+ && tree_int_cst_compare (high, max_value) > 0)
+ high = max_value;
+ high = fold_convert (type, high);
+ }
+
/* Add this label to the chain. */
r = ggc_alloc (sizeof (struct case_node));
{
tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE;
rtx default_label = 0;
- struct case_node *n, *m;
+ struct case_node *n;
unsigned int count, uniq;
rtx index;
rtx table_label;
int ncases;
rtx *labelvec;
- int i;
+ int i, fail;
rtx before_case, end, lab;
tree vec = SWITCH_LABELS (exp);
struct case_node *case_list = 0;
/* Label to jump to if no case matches. */
- tree default_label_decl = 0;
+ tree default_label_decl;
/* The switch body is lowered in gimplify.c, we should never have
switches with a non-NULL SWITCH_BODY here. */
gcc_assert (!SWITCH_BODY (exp));
gcc_assert (SWITCH_LABELS (exp));
- for (i = TREE_VEC_LENGTH (vec); --i >= 0; )
- {
- tree elt = TREE_VEC_ELT (vec, i);
-
- /* Handle default labels specially. */
- if (!CASE_HIGH (elt) && !CASE_LOW (elt))
- {
- gcc_assert (!default_label_decl);
- default_label_decl = CASE_LABEL (elt);
- }
- else
- case_list = add_case_node (case_list, CASE_LOW (elt), CASE_HIGH (elt),
- CASE_LABEL (elt));
- }
-
do_pending_stack_adjust ();
- /* Make sure start points to something that won't need any transformation
- before the end of this function. */
- if (!NOTE_P (get_last_insn ()))
- emit_note (NOTE_INSN_DELETED);
-
- start = get_last_insn ();
-
/* An ERROR_MARK occurs for various reasons including invalid data type. */
if (index_type != error_mark_node)
{
- int fail;
+ tree elt;
+ bitmap label_bitmap;
+
+ /* cleanup_tree_cfg removes all SWITCH_EXPR with their index
+ expressions being INTEGER_CST. */
+ gcc_assert (TREE_CODE (index_expr) != INTEGER_CST);
+
+ /* The default case is at the end of TREE_VEC. */
+ elt = TREE_VEC_ELT (vec, TREE_VEC_LENGTH (vec) - 1);
+ gcc_assert (!CASE_HIGH (elt));
+ gcc_assert (!CASE_LOW (elt));
+ default_label_decl = CASE_LABEL (elt);
- /* If we don't have a default-label, create one here,
- after the body of the switch. */
- if (default_label_decl == 0)
+ for (i = TREE_VEC_LENGTH (vec) - 1; --i >= 0; )
{
- default_label_decl
- = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
- expand_label (default_label_decl);
+ elt = TREE_VEC_ELT (vec, i);
+ gcc_assert (CASE_LOW (elt));
+ case_list = add_case_node (case_list, index_type,
+ CASE_LOW (elt), CASE_HIGH (elt),
+ CASE_LABEL (elt));
}
+
+
+ /* Make sure start points to something that won't need any
+ transformation before the end of this function. */
+ start = get_last_insn ();
+ if (! NOTE_P (start))
+ {
+ emit_note (NOTE_INSN_DELETED);
+ start = get_last_insn ();
+ }
+
default_label = label_rtx (default_label_decl);
before_case = get_last_insn ();
- /* Get upper and lower bounds of case values.
- Also convert all the case values to the index expr's data type. */
+ /* Get upper and lower bounds of case values. */
uniq = 0;
count = 0;
+ label_bitmap = BITMAP_XMALLOC ();
for (n = case_list; n; n = n->right)
{
- /* Check low and high label values are integers. */
- gcc_assert (TREE_CODE (n->low) == INTEGER_CST);
- gcc_assert (TREE_CODE (n->high) == INTEGER_CST);
-
- n->low = convert (index_type, n->low);
- n->high = convert (index_type, n->high);
-
/* Count the elements and track the largest and smallest
of them (treating them as signed even if they are not). */
if (count++ == 0)
if (! tree_int_cst_equal (n->low, n->high))
count++;
- /* Count the number of unique case node targets. */
- uniq++;
+ /* If we have not seen this label yet, then increase the
+ number of unique case node targets seen. */
lab = label_rtx (n->code_label);
- for (m = case_list; m != n; m = m->right)
- if (label_rtx (m->code_label) == lab)
- {
- uniq--;
- break;
- }
+ if (!bitmap_bit_p (label_bitmap, CODE_LABEL_NUMBER (lab)))
+ {
+ bitmap_set_bit (label_bitmap, CODE_LABEL_NUMBER (lab));
+ uniq++;
+ }
}
- /* Compute span of values. */
- if (count != 0)
- range = fold (build2 (MINUS_EXPR, index_type, maxval, minval));
+ BITMAP_XFREE (label_bitmap);
- if (count == 0)
- {
- expand_expr (index_expr, const0_rtx, VOIDmode, 0);
- emit_jump (default_label);
- }
+ /* cleanup_tree_cfg removes all SWITCH_EXPR with a single
+ destination, such as one with a default case only. */
+ gcc_assert (count != 0);
+
+ /* Compute span of values. */
+ range = fold (build2 (MINUS_EXPR, index_type, maxval, minval));
/* 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. */
- else 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 (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)))
{
/* Optimize the case where all the case values fit in a
word without having to subtract MINVAL. In this case,
if (MEM_P (index))
index = copy_to_reg (index);
- if (GET_CODE (index) == CONST_INT
- || TREE_CODE (index_expr) == INTEGER_CST)
- {
- /* Make a tree node with the proper constant value
- if we don't already have one. */
- if (TREE_CODE (index_expr) != INTEGER_CST)
- {
- index_expr
- = build_int_cst_wide (NULL_TREE, INTVAL (index),
- unsignedp || INTVAL (index) >= 0
- ? 0 : -1);
- index_expr = convert (index_type, index_expr);
- }
- /* For constant index expressions we need only
- issue an unconditional branch to the appropriate
- target code. The job of removing any unreachable
- code is left to the optimization phase if the
- "-O" option is specified. */
- for (n = case_list; n; n = n->right)
- if (! tree_int_cst_lt (index_expr, n->low)
- && ! tree_int_cst_lt (n->high, index_expr))
- break;
-
- if (n)
- emit_jump (label_rtx (n->code_label));
- else
- emit_jump (default_label);
- }
- else
- {
- /* If the index expression is not constant we generate
- a binary decision tree to select the appropriate
- target code. This is done as follows:
+ /* We generate a binary decision tree to select the
+ appropriate target code. This is done as follows:
- The list of cases is rearranged into a binary tree,
- nearly optimal assuming equal probability for each case.
+ The list of cases is rearranged into a binary tree,
+ nearly optimal assuming equal probability for each case.
- The tree is transformed into RTL, eliminating
- redundant test conditions at the same time.
+ The tree is transformed into RTL, eliminating
+ redundant test conditions at the same time.
- If program flow could reach the end of the
- decision tree an unconditional jump to the
- default code is emitted. */
+ If program flow could reach the end of the
+ decision tree an unconditional jump to the
+ default code is emitted. */
- use_cost_table
- = (TREE_CODE (orig_type) != ENUMERAL_TYPE
- && estimate_case_costs (case_list));
- balance_case_nodes (&case_list, NULL);
- emit_case_nodes (index, case_list, default_label, index_type);
- emit_jump (default_label);
- }
+ use_cost_table
+ = (TREE_CODE (orig_type) != ENUMERAL_TYPE
+ && estimate_case_costs (case_list));
+ balance_case_nodes (&case_list, NULL);
+ emit_case_nodes (index, case_list, default_label, index_type);
+ emit_jump (default_label);
}
else
{
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