1 /* Expands front end tree to back end RTL for GCC
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
22 /* This file handles the generation of rtl code from tree structure
23 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
24 The functions whose names start with `expand_' are called by the
25 expander to generate RTL instructions for various kinds of constructs. */
29 #include "coretypes.h"
38 #include "insn-config.h"
41 #include "hard-reg-set.h"
47 #include "langhooks.h"
53 /* Functions and data structures for expanding case statements. */
55 /* Case label structure, used to hold info on labels within case
56 statements. We handle "range" labels; for a single-value label
57 as in C, the high and low limits are the same.
59 We start with a vector of case nodes sorted in ascending order, and
60 the default label as the last element in the vector. Before expanding
61 to RTL, we transform this vector into a list linked via the RIGHT
62 fields in the case_node struct. Nodes with higher case values are
65 Switch statements can be output in three forms. A branch table is
66 used if there are more than a few labels and the labels are dense
67 within the range between the smallest and largest case value. If a
68 branch table is used, no further manipulations are done with the case
71 The alternative to the use of a branch table is to generate a series
72 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
73 and PARENT fields to hold a binary tree. Initially the tree is
74 totally unbalanced, with everything on the right. We balance the tree
75 with nodes on the left having lower case values than the parent
76 and nodes on the right having higher values. We then output the tree
79 For very small, suitable switch statements, we can generate a series
80 of simple bit test and branches instead. */
82 struct case_node GTY(())
84 struct case_node *left; /* Left son in binary tree */
85 struct case_node *right; /* Right son in binary tree; also node chain */
86 struct case_node *parent; /* Parent of node in binary tree */
87 tree low; /* Lowest index value for this label */
88 tree high; /* Highest index value for this label */
89 tree code_label; /* Label to jump to when node matches */
92 typedef struct case_node case_node;
93 typedef struct case_node *case_node_ptr;
95 /* These are used by estimate_case_costs and balance_case_nodes. */
97 /* This must be a signed type, and non-ANSI compilers lack signed char. */
98 static short cost_table_[129];
99 static int use_cost_table;
100 static int cost_table_initialized;
102 /* Special care is needed because we allow -1, but TREE_INT_CST_LOW
104 #define COST_TABLE(I) cost_table_[(unsigned HOST_WIDE_INT) ((I) + 1)]
106 static int n_occurrences (int, const char *);
107 static bool decl_conflicts_with_clobbers_p (tree, const HARD_REG_SET);
108 static void expand_nl_goto_receiver (void);
109 static bool check_operand_nalternatives (tree, tree);
110 static bool check_unique_operand_names (tree, tree);
111 static char *resolve_operand_name_1 (char *, tree, tree);
112 static void expand_null_return_1 (void);
113 static rtx shift_return_value (rtx);
114 static void expand_value_return (rtx);
115 static void do_jump_if_equal (rtx, rtx, rtx, int);
116 static int estimate_case_costs (case_node_ptr);
117 static bool lshift_cheap_p (void);
118 static int case_bit_test_cmp (const void *, const void *);
119 static void emit_case_bit_tests (tree, tree, tree, tree, case_node_ptr, rtx);
120 static void balance_case_nodes (case_node_ptr *, case_node_ptr);
121 static int node_has_low_bound (case_node_ptr, tree);
122 static int node_has_high_bound (case_node_ptr, tree);
123 static int node_is_bounded (case_node_ptr, tree);
124 static void emit_case_nodes (rtx, case_node_ptr, rtx, tree);
125 static struct case_node *add_case_node (struct case_node *, tree,
129 /* Return the rtx-label that corresponds to a LABEL_DECL,
130 creating it if necessary. */
133 label_rtx (tree label)
135 gcc_assert (TREE_CODE (label) == LABEL_DECL);
137 if (!DECL_RTL_SET_P (label))
139 rtx r = gen_label_rtx ();
140 SET_DECL_RTL (label, r);
141 if (FORCED_LABEL (label) || DECL_NONLOCAL (label))
142 LABEL_PRESERVE_P (r) = 1;
145 return DECL_RTL (label);
148 /* As above, but also put it on the forced-reference list of the
149 function that contains it. */
151 force_label_rtx (tree label)
153 rtx ref = label_rtx (label);
154 tree function = decl_function_context (label);
157 gcc_assert (function);
159 if (function != current_function_decl)
160 p = find_function_data (function);
164 p->expr->x_forced_labels = gen_rtx_EXPR_LIST (VOIDmode, ref,
165 p->expr->x_forced_labels);
169 /* Add an unconditional jump to LABEL as the next sequential instruction. */
172 emit_jump (rtx label)
174 do_pending_stack_adjust ();
175 emit_jump_insn (gen_jump (label));
179 /* Emit code to jump to the address
180 specified by the pointer expression EXP. */
183 expand_computed_goto (tree exp)
185 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
187 x = convert_memory_address (Pmode, x);
189 do_pending_stack_adjust ();
190 emit_indirect_jump (x);
193 /* Handle goto statements and the labels that they can go to. */
195 /* Specify the location in the RTL code of a label LABEL,
196 which is a LABEL_DECL tree node.
198 This is used for the kind of label that the user can jump to with a
199 goto statement, and for alternatives of a switch or case statement.
200 RTL labels generated for loops and conditionals don't go through here;
201 they are generated directly at the RTL level, by other functions below.
203 Note that this has nothing to do with defining label *names*.
204 Languages vary in how they do that and what that even means. */
207 expand_label (tree label)
209 rtx label_r = label_rtx (label);
211 do_pending_stack_adjust ();
212 emit_label (label_r);
213 if (DECL_NAME (label))
214 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
216 if (DECL_NONLOCAL (label))
218 expand_nl_goto_receiver ();
219 nonlocal_goto_handler_labels
220 = gen_rtx_EXPR_LIST (VOIDmode, label_r,
221 nonlocal_goto_handler_labels);
224 if (FORCED_LABEL (label))
225 forced_labels = gen_rtx_EXPR_LIST (VOIDmode, label_r, forced_labels);
227 if (DECL_NONLOCAL (label) || FORCED_LABEL (label))
228 maybe_set_first_label_num (label_r);
231 /* Generate RTL code for a `goto' statement with target label LABEL.
232 LABEL should be a LABEL_DECL tree node that was or will later be
233 defined with `expand_label'. */
236 expand_goto (tree label)
238 #ifdef ENABLE_CHECKING
239 /* Check for a nonlocal goto to a containing function. Should have
240 gotten translated to __builtin_nonlocal_goto. */
241 tree context = decl_function_context (label);
242 gcc_assert (!context || context == current_function_decl);
245 emit_jump (label_rtx (label));
248 /* Return the number of times character C occurs in string S. */
250 n_occurrences (int c, const char *s)
258 /* Generate RTL for an asm statement (explicit assembler code).
259 STRING is a STRING_CST node containing the assembler code text,
260 or an ADDR_EXPR containing a STRING_CST. VOL nonzero means the
261 insn is volatile; don't optimize it. */
264 expand_asm (tree string, int vol)
268 if (TREE_CODE (string) == ADDR_EXPR)
269 string = TREE_OPERAND (string, 0);
271 body = gen_rtx_ASM_INPUT (VOIDmode,
272 ggc_strdup (TREE_STRING_POINTER (string)));
274 MEM_VOLATILE_P (body) = vol;
279 /* Parse the output constraint pointed to by *CONSTRAINT_P. It is the
280 OPERAND_NUMth output operand, indexed from zero. There are NINPUTS
281 inputs and NOUTPUTS outputs to this extended-asm. Upon return,
282 *ALLOWS_MEM will be TRUE iff the constraint allows the use of a
283 memory operand. Similarly, *ALLOWS_REG will be TRUE iff the
284 constraint allows the use of a register operand. And, *IS_INOUT
285 will be true if the operand is read-write, i.e., if it is used as
286 an input as well as an output. If *CONSTRAINT_P is not in
287 canonical form, it will be made canonical. (Note that `+' will be
288 replaced with `=' as part of this process.)
290 Returns TRUE if all went well; FALSE if an error occurred. */
293 parse_output_constraint (const char **constraint_p, int operand_num,
294 int ninputs, int noutputs, bool *allows_mem,
295 bool *allows_reg, bool *is_inout)
297 const char *constraint = *constraint_p;
300 /* Assume the constraint doesn't allow the use of either a register
305 /* Allow the `=' or `+' to not be at the beginning of the string,
306 since it wasn't explicitly documented that way, and there is a
307 large body of code that puts it last. Swap the character to
308 the front, so as not to uglify any place else. */
309 p = strchr (constraint, '=');
311 p = strchr (constraint, '+');
313 /* If the string doesn't contain an `=', issue an error
317 error ("output operand constraint lacks %<=%>");
321 /* If the constraint begins with `+', then the operand is both read
322 from and written to. */
323 *is_inout = (*p == '+');
325 /* Canonicalize the output constraint so that it begins with `='. */
326 if (p != constraint || is_inout)
329 size_t c_len = strlen (constraint);
332 warning ("output constraint %qc for operand %d "
333 "is not at the beginning",
336 /* Make a copy of the constraint. */
337 buf = alloca (c_len + 1);
338 strcpy (buf, constraint);
339 /* Swap the first character and the `=' or `+'. */
340 buf[p - constraint] = buf[0];
341 /* Make sure the first character is an `='. (Until we do this,
342 it might be a `+'.) */
344 /* Replace the constraint with the canonicalized string. */
345 *constraint_p = ggc_alloc_string (buf, c_len);
346 constraint = *constraint_p;
349 /* Loop through the constraint string. */
350 for (p = constraint + 1; *p; p += CONSTRAINT_LEN (*p, p))
355 error ("operand constraint contains incorrectly positioned "
360 if (operand_num + 1 == ninputs + noutputs)
362 error ("%<%%%> constraint used with last operand");
367 case 'V': case 'm': case 'o':
371 case '?': case '!': case '*': case '&': case '#':
372 case 'E': case 'F': case 'G': case 'H':
373 case 's': case 'i': case 'n':
374 case 'I': case 'J': case 'K': case 'L': case 'M':
375 case 'N': case 'O': case 'P': case ',':
378 case '0': case '1': case '2': case '3': case '4':
379 case '5': case '6': case '7': case '8': case '9':
381 error ("matching constraint not valid in output operand");
385 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
386 excepting those that expand_call created. So match memory
403 if (REG_CLASS_FROM_CONSTRAINT (*p, p) != NO_REGS)
405 #ifdef EXTRA_CONSTRAINT_STR
406 else if (EXTRA_ADDRESS_CONSTRAINT (*p, p))
408 else if (EXTRA_MEMORY_CONSTRAINT (*p, p))
412 /* Otherwise we can't assume anything about the nature of
413 the constraint except that it isn't purely registers.
414 Treat it like "g" and hope for the best. */
425 /* Similar, but for input constraints. */
428 parse_input_constraint (const char **constraint_p, int input_num,
429 int ninputs, int noutputs, int ninout,
430 const char * const * constraints,
431 bool *allows_mem, bool *allows_reg)
433 const char *constraint = *constraint_p;
434 const char *orig_constraint = constraint;
435 size_t c_len = strlen (constraint);
437 bool saw_match = false;
439 /* Assume the constraint doesn't allow the use of either
440 a register or memory. */
444 /* Make sure constraint has neither `=', `+', nor '&'. */
446 for (j = 0; j < c_len; j += CONSTRAINT_LEN (constraint[j], constraint+j))
447 switch (constraint[j])
449 case '+': case '=': case '&':
450 if (constraint == orig_constraint)
452 error ("input operand constraint contains %qc", constraint[j]);
458 if (constraint == orig_constraint
459 && input_num + 1 == ninputs - ninout)
461 error ("%<%%%> constraint used with last operand");
466 case 'V': case 'm': case 'o':
471 case '?': case '!': case '*': case '#':
472 case 'E': case 'F': case 'G': case 'H':
473 case 's': case 'i': case 'n':
474 case 'I': case 'J': case 'K': case 'L': case 'M':
475 case 'N': case 'O': case 'P': case ',':
478 /* Whether or not a numeric constraint allows a register is
479 decided by the matching constraint, and so there is no need
480 to do anything special with them. We must handle them in
481 the default case, so that we don't unnecessarily force
482 operands to memory. */
483 case '0': case '1': case '2': case '3': case '4':
484 case '5': case '6': case '7': case '8': case '9':
491 match = strtoul (constraint + j, &end, 10);
492 if (match >= (unsigned long) noutputs)
494 error ("matching constraint references invalid operand number");
498 /* Try and find the real constraint for this dup. Only do this
499 if the matching constraint is the only alternative. */
501 && (j == 0 || (j == 1 && constraint[0] == '%')))
503 constraint = constraints[match];
504 *constraint_p = constraint;
505 c_len = strlen (constraint);
507 /* ??? At the end of the loop, we will skip the first part of
508 the matched constraint. This assumes not only that the
509 other constraint is an output constraint, but also that
510 the '=' or '+' come first. */
514 j = end - constraint;
515 /* Anticipate increment at end of loop. */
530 if (! ISALPHA (constraint[j]))
532 error ("invalid punctuation %qc in constraint", constraint[j]);
535 if (REG_CLASS_FROM_CONSTRAINT (constraint[j], constraint + j)
538 #ifdef EXTRA_CONSTRAINT_STR
539 else if (EXTRA_ADDRESS_CONSTRAINT (constraint[j], constraint + j))
541 else if (EXTRA_MEMORY_CONSTRAINT (constraint[j], constraint + j))
545 /* Otherwise we can't assume anything about the nature of
546 the constraint except that it isn't purely registers.
547 Treat it like "g" and hope for the best. */
555 if (saw_match && !*allows_reg)
556 warning ("matching constraint does not allow a register");
561 /* INPUT is one of the input operands from EXPR, an ASM_EXPR. Returns true
562 if it is an operand which must be passed in memory (i.e. an "m"
563 constraint), false otherwise. */
566 asm_op_is_mem_input (tree input, tree expr)
568 const char *constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (input)));
569 tree outputs = ASM_OUTPUTS (expr);
570 int noutputs = list_length (outputs);
571 const char **constraints
572 = (const char **) alloca ((noutputs) * sizeof (const char *));
574 bool allows_mem, allows_reg;
577 /* Collect output constraints. */
578 for (t = outputs; t ; t = TREE_CHAIN (t), i++)
579 constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
581 /* We pass 0 for input_num, ninputs and ninout; they are only used for
582 error checking which will be done at expand time. */
583 parse_input_constraint (&constraint, 0, 0, noutputs, 0, constraints,
584 &allows_mem, &allows_reg);
585 return (!allows_reg && allows_mem);
588 /* Check for overlap between registers marked in CLOBBERED_REGS and
589 anything inappropriate in DECL. Emit error and return TRUE for error,
593 decl_conflicts_with_clobbers_p (tree decl, const HARD_REG_SET clobbered_regs)
595 /* Conflicts between asm-declared register variables and the clobber
596 list are not allowed. */
597 if ((TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == PARM_DECL)
598 && DECL_REGISTER (decl)
599 && REG_P (DECL_RTL (decl))
600 && REGNO (DECL_RTL (decl)) < FIRST_PSEUDO_REGISTER)
602 rtx reg = DECL_RTL (decl);
605 for (regno = REGNO (reg);
607 + hard_regno_nregs[REGNO (reg)][GET_MODE (reg)]);
609 if (TEST_HARD_REG_BIT (clobbered_regs, regno))
611 error ("asm-specifier for variable %qs conflicts with "
613 IDENTIFIER_POINTER (DECL_NAME (decl)));
615 /* Reset registerness to stop multiple errors emitted for a
617 DECL_REGISTER (decl) = 0;
624 /* Generate RTL for an asm statement with arguments.
625 STRING is the instruction template.
626 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
627 Each output or input has an expression in the TREE_VALUE and
628 and a tree list in TREE_PURPOSE which in turn contains a constraint
629 name in TREE_VALUE (or NULL_TREE) and a constraint string
631 CLOBBERS is a list of STRING_CST nodes each naming a hard register
632 that is clobbered by this insn.
634 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
635 Some elements of OUTPUTS may be replaced with trees representing temporary
636 values. The caller should copy those temporary values to the originally
639 VOL nonzero means the insn is volatile; don't optimize it. */
642 expand_asm_operands (tree string, tree outputs, tree inputs,
643 tree clobbers, int vol, location_t locus)
645 rtvec argvec, constraintvec;
647 int ninputs = list_length (inputs);
648 int noutputs = list_length (outputs);
651 HARD_REG_SET clobbered_regs;
652 int clobber_conflict_found = 0;
656 /* Vector of RTX's of evaluated output operands. */
657 rtx *output_rtx = alloca (noutputs * sizeof (rtx));
658 int *inout_opnum = alloca (noutputs * sizeof (int));
659 rtx *real_output_rtx = alloca (noutputs * sizeof (rtx));
660 enum machine_mode *inout_mode
661 = alloca (noutputs * sizeof (enum machine_mode));
662 const char **constraints
663 = alloca ((noutputs + ninputs) * sizeof (const char *));
664 int old_generating_concat_p = generating_concat_p;
666 /* An ASM with no outputs needs to be treated as volatile, for now. */
670 if (! check_operand_nalternatives (outputs, inputs))
673 string = resolve_asm_operand_names (string, outputs, inputs);
675 /* Collect constraints. */
677 for (t = outputs; t ; t = TREE_CHAIN (t), i++)
678 constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
679 for (t = inputs; t ; t = TREE_CHAIN (t), i++)
680 constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
682 /* Sometimes we wish to automatically clobber registers across an asm.
683 Case in point is when the i386 backend moved from cc0 to a hard reg --
684 maintaining source-level compatibility means automatically clobbering
685 the flags register. */
686 clobbers = targetm.md_asm_clobbers (clobbers);
688 /* Count the number of meaningful clobbered registers, ignoring what
689 we would ignore later. */
691 CLEAR_HARD_REG_SET (clobbered_regs);
692 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
694 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
696 i = decode_reg_name (regname);
697 if (i >= 0 || i == -4)
700 error ("unknown register name %qs in %<asm%>", regname);
702 /* Mark clobbered registers. */
705 /* Clobbering the PIC register is an error. */
706 if (i == (int) PIC_OFFSET_TABLE_REGNUM)
708 error ("PIC register %qs clobbered in %<asm%>", regname);
712 SET_HARD_REG_BIT (clobbered_regs, i);
716 /* First pass over inputs and outputs checks validity and sets
717 mark_addressable if needed. */
720 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
722 tree val = TREE_VALUE (tail);
723 tree type = TREE_TYPE (val);
724 const char *constraint;
729 /* If there's an erroneous arg, emit no insn. */
730 if (type == error_mark_node)
733 /* Try to parse the output constraint. If that fails, there's
734 no point in going further. */
735 constraint = constraints[i];
736 if (!parse_output_constraint (&constraint, i, ninputs, noutputs,
737 &allows_mem, &allows_reg, &is_inout))
744 && REG_P (DECL_RTL (val))
745 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type))))
746 lang_hooks.mark_addressable (val);
753 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
755 error ("more than %d operands in %<asm%>", MAX_RECOG_OPERANDS);
759 for (i = 0, tail = inputs; tail; i++, tail = TREE_CHAIN (tail))
761 bool allows_reg, allows_mem;
762 const char *constraint;
764 /* If there's an erroneous arg, emit no insn, because the ASM_INPUT
765 would get VOIDmode and that could cause a crash in reload. */
766 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
769 constraint = constraints[i + noutputs];
770 if (! parse_input_constraint (&constraint, i, ninputs, noutputs, ninout,
771 constraints, &allows_mem, &allows_reg))
774 if (! allows_reg && allows_mem)
775 lang_hooks.mark_addressable (TREE_VALUE (tail));
778 /* Second pass evaluates arguments. */
781 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
783 tree val = TREE_VALUE (tail);
784 tree type = TREE_TYPE (val);
791 ok = parse_output_constraint (&constraints[i], i, ninputs,
792 noutputs, &allows_mem, &allows_reg,
796 /* If an output operand is not a decl or indirect ref and our constraint
797 allows a register, make a temporary to act as an intermediate.
798 Make the asm insn write into that, then our caller will copy it to
799 the real output operand. Likewise for promoted variables. */
801 generating_concat_p = 0;
803 real_output_rtx[i] = NULL_RTX;
804 if ((TREE_CODE (val) == INDIRECT_REF
807 && (allows_mem || REG_P (DECL_RTL (val)))
808 && ! (REG_P (DECL_RTL (val))
809 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
813 op = expand_expr (val, NULL_RTX, VOIDmode, EXPAND_WRITE);
815 op = validize_mem (op);
817 if (! allows_reg && !MEM_P (op))
818 error ("output number %d not directly addressable", i);
819 if ((! allows_mem && MEM_P (op))
820 || GET_CODE (op) == CONCAT)
822 real_output_rtx[i] = op;
823 op = gen_reg_rtx (GET_MODE (op));
825 emit_move_insn (op, real_output_rtx[i]);
830 op = assign_temp (type, 0, 0, 1);
831 op = validize_mem (op);
832 TREE_VALUE (tail) = make_tree (type, op);
836 generating_concat_p = old_generating_concat_p;
840 inout_mode[ninout] = TYPE_MODE (type);
841 inout_opnum[ninout++] = i;
844 if (decl_conflicts_with_clobbers_p (val, clobbered_regs))
845 clobber_conflict_found = 1;
848 /* Make vectors for the expression-rtx, constraint strings,
849 and named operands. */
851 argvec = rtvec_alloc (ninputs);
852 constraintvec = rtvec_alloc (ninputs);
854 body = gen_rtx_ASM_OPERANDS ((noutputs == 0 ? VOIDmode
855 : GET_MODE (output_rtx[0])),
856 ggc_strdup (TREE_STRING_POINTER (string)),
857 empty_string, 0, argvec, constraintvec,
860 MEM_VOLATILE_P (body) = vol;
862 /* Eval the inputs and put them into ARGVEC.
863 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
865 for (i = 0, tail = inputs; tail; tail = TREE_CHAIN (tail), ++i)
867 bool allows_reg, allows_mem;
868 const char *constraint;
873 constraint = constraints[i + noutputs];
874 ok = parse_input_constraint (&constraint, i, ninputs, noutputs, ninout,
875 constraints, &allows_mem, &allows_reg);
878 generating_concat_p = 0;
880 val = TREE_VALUE (tail);
881 type = TREE_TYPE (val);
882 op = expand_expr (val, NULL_RTX, VOIDmode,
883 (allows_mem && !allows_reg
884 ? EXPAND_MEMORY : EXPAND_NORMAL));
886 /* Never pass a CONCAT to an ASM. */
887 if (GET_CODE (op) == CONCAT)
888 op = force_reg (GET_MODE (op), op);
890 op = validize_mem (op);
892 if (asm_operand_ok (op, constraint) <= 0)
895 op = force_reg (TYPE_MODE (type), op);
896 else if (!allows_mem)
897 warning ("asm operand %d probably doesn%'t match constraints",
901 /* We won't recognize either volatile memory or memory
902 with a queued address as available a memory_operand
903 at this point. Ignore it: clearly this *is* a memory. */
907 warning ("use of memory input without lvalue in "
908 "asm operand %d is deprecated", i + noutputs);
912 rtx mem = force_const_mem (TYPE_MODE (type), op);
914 op = validize_mem (mem);
916 op = force_reg (TYPE_MODE (type), op);
919 || GET_CODE (op) == SUBREG
920 || GET_CODE (op) == CONCAT)
922 tree qual_type = build_qualified_type (type,
925 rtx memloc = assign_temp (qual_type, 1, 1, 1);
926 memloc = validize_mem (memloc);
927 emit_move_insn (memloc, op);
933 generating_concat_p = old_generating_concat_p;
934 ASM_OPERANDS_INPUT (body, i) = op;
936 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, i)
937 = gen_rtx_ASM_INPUT (TYPE_MODE (type),
938 ggc_strdup (constraints[i + noutputs]));
940 if (decl_conflicts_with_clobbers_p (val, clobbered_regs))
941 clobber_conflict_found = 1;
944 /* Protect all the operands from the queue now that they have all been
947 generating_concat_p = 0;
949 /* For in-out operands, copy output rtx to input rtx. */
950 for (i = 0; i < ninout; i++)
952 int j = inout_opnum[i];
955 ASM_OPERANDS_INPUT (body, ninputs - ninout + i)
958 sprintf (buffer, "%d", j);
959 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, ninputs - ninout + i)
960 = gen_rtx_ASM_INPUT (inout_mode[i], ggc_strdup (buffer));
963 generating_concat_p = old_generating_concat_p;
965 /* Now, for each output, construct an rtx
966 (set OUTPUT (asm_operands INSN OUTPUTCONSTRAINT OUTPUTNUMBER
967 ARGVEC CONSTRAINTS OPNAMES))
968 If there is more than one, put them inside a PARALLEL. */
970 if (noutputs == 1 && nclobbers == 0)
972 ASM_OPERANDS_OUTPUT_CONSTRAINT (body) = ggc_strdup (constraints[0]);
973 emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
976 else if (noutputs == 0 && nclobbers == 0)
978 /* No output operands: put in a raw ASM_OPERANDS rtx. */
990 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
992 /* For each output operand, store a SET. */
993 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
996 = gen_rtx_SET (VOIDmode,
999 (GET_MODE (output_rtx[i]),
1000 ggc_strdup (TREE_STRING_POINTER (string)),
1001 ggc_strdup (constraints[i]),
1002 i, argvec, constraintvec, locus));
1004 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1007 /* If there are no outputs (but there are some clobbers)
1008 store the bare ASM_OPERANDS into the PARALLEL. */
1011 XVECEXP (body, 0, i++) = obody;
1013 /* Store (clobber REG) for each clobbered register specified. */
1015 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1017 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1018 int j = decode_reg_name (regname);
1023 if (j == -3) /* `cc', which is not a register */
1026 if (j == -4) /* `memory', don't cache memory across asm */
1028 XVECEXP (body, 0, i++)
1029 = gen_rtx_CLOBBER (VOIDmode,
1032 gen_rtx_SCRATCH (VOIDmode)));
1036 /* Ignore unknown register, error already signaled. */
1040 /* Use QImode since that's guaranteed to clobber just one reg. */
1041 clobbered_reg = gen_rtx_REG (QImode, j);
1043 /* Do sanity check for overlap between clobbers and respectively
1044 input and outputs that hasn't been handled. Such overlap
1045 should have been detected and reported above. */
1046 if (!clobber_conflict_found)
1050 /* We test the old body (obody) contents to avoid tripping
1051 over the under-construction body. */
1052 for (opno = 0; opno < noutputs; opno++)
1053 if (reg_overlap_mentioned_p (clobbered_reg, output_rtx[opno]))
1054 internal_error ("asm clobber conflict with output operand");
1056 for (opno = 0; opno < ninputs - ninout; opno++)
1057 if (reg_overlap_mentioned_p (clobbered_reg,
1058 ASM_OPERANDS_INPUT (obody, opno)))
1059 internal_error ("asm clobber conflict with input operand");
1062 XVECEXP (body, 0, i++)
1063 = gen_rtx_CLOBBER (VOIDmode, clobbered_reg);
1069 /* For any outputs that needed reloading into registers, spill them
1070 back to where they belong. */
1071 for (i = 0; i < noutputs; ++i)
1072 if (real_output_rtx[i])
1073 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1079 expand_asm_expr (tree exp)
1085 if (ASM_INPUT_P (exp))
1087 expand_asm (ASM_STRING (exp), ASM_VOLATILE_P (exp));
1091 outputs = ASM_OUTPUTS (exp);
1092 noutputs = list_length (outputs);
1093 /* o[I] is the place that output number I should be written. */
1094 o = (tree *) alloca (noutputs * sizeof (tree));
1096 /* Record the contents of OUTPUTS before it is modified. */
1097 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1098 o[i] = TREE_VALUE (tail);
1100 /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
1101 OUTPUTS some trees for where the values were actually stored. */
1102 expand_asm_operands (ASM_STRING (exp), outputs, ASM_INPUTS (exp),
1103 ASM_CLOBBERS (exp), ASM_VOLATILE_P (exp),
1106 /* Copy all the intermediate outputs into the specified outputs. */
1107 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1109 if (o[i] != TREE_VALUE (tail))
1111 expand_assignment (o[i], TREE_VALUE (tail), 0);
1114 /* Restore the original value so that it's correct the next
1115 time we expand this function. */
1116 TREE_VALUE (tail) = o[i];
1121 /* A subroutine of expand_asm_operands. Check that all operands have
1122 the same number of alternatives. Return true if so. */
1125 check_operand_nalternatives (tree outputs, tree inputs)
1127 if (outputs || inputs)
1129 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1131 = n_occurrences (',', TREE_STRING_POINTER (TREE_VALUE (tmp)));
1134 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1136 error ("too many alternatives in %<asm%>");
1143 const char *constraint
1144 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tmp)));
1146 if (n_occurrences (',', constraint) != nalternatives)
1148 error ("operand constraints for %<asm%> differ "
1149 "in number of alternatives");
1153 if (TREE_CHAIN (tmp))
1154 tmp = TREE_CHAIN (tmp);
1156 tmp = next, next = 0;
1163 /* A subroutine of expand_asm_operands. Check that all operand names
1164 are unique. Return true if so. We rely on the fact that these names
1165 are identifiers, and so have been canonicalized by get_identifier,
1166 so all we need are pointer comparisons. */
1169 check_unique_operand_names (tree outputs, tree inputs)
1173 for (i = outputs; i ; i = TREE_CHAIN (i))
1175 tree i_name = TREE_PURPOSE (TREE_PURPOSE (i));
1179 for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j))
1180 if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
1184 for (i = inputs; i ; i = TREE_CHAIN (i))
1186 tree i_name = TREE_PURPOSE (TREE_PURPOSE (i));
1190 for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j))
1191 if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
1193 for (j = outputs; j ; j = TREE_CHAIN (j))
1194 if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
1201 error ("duplicate asm operand name %qs",
1202 TREE_STRING_POINTER (TREE_PURPOSE (TREE_PURPOSE (i))));
1206 /* A subroutine of expand_asm_operands. Resolve the names of the operands
1207 in *POUTPUTS and *PINPUTS to numbers, and replace the name expansions in
1208 STRING and in the constraints to those numbers. */
1211 resolve_asm_operand_names (tree string, tree outputs, tree inputs)
1218 check_unique_operand_names (outputs, inputs);
1220 /* Substitute [<name>] in input constraint strings. There should be no
1221 named operands in output constraints. */
1222 for (t = inputs; t ; t = TREE_CHAIN (t))
1224 c = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
1225 if (strchr (c, '[') != NULL)
1227 p = buffer = xstrdup (c);
1228 while ((p = strchr (p, '[')) != NULL)
1229 p = resolve_operand_name_1 (p, outputs, inputs);
1230 TREE_VALUE (TREE_PURPOSE (t))
1231 = build_string (strlen (buffer), buffer);
1236 /* Now check for any needed substitutions in the template. */
1237 c = TREE_STRING_POINTER (string);
1238 while ((c = strchr (c, '%')) != NULL)
1242 else if (ISALPHA (c[1]) && c[2] == '[')
1253 /* OK, we need to make a copy so we can perform the substitutions.
1254 Assume that we will not need extra space--we get to remove '['
1255 and ']', which means we cannot have a problem until we have more
1256 than 999 operands. */
1257 buffer = xstrdup (TREE_STRING_POINTER (string));
1258 p = buffer + (c - TREE_STRING_POINTER (string));
1260 while ((p = strchr (p, '%')) != NULL)
1264 else if (ISALPHA (p[1]) && p[2] == '[')
1272 p = resolve_operand_name_1 (p, outputs, inputs);
1275 string = build_string (strlen (buffer), buffer);
1282 /* A subroutine of resolve_operand_names. P points to the '[' for a
1283 potential named operand of the form [<name>]. In place, replace
1284 the name and brackets with a number. Return a pointer to the
1285 balance of the string after substitution. */
1288 resolve_operand_name_1 (char *p, tree outputs, tree inputs)
1295 /* Collect the operand name. */
1296 q = strchr (p, ']');
1299 error ("missing close brace for named operand");
1300 return strchr (p, '\0');
1304 /* Resolve the name to a number. */
1305 for (op = 0, t = outputs; t ; t = TREE_CHAIN (t), op++)
1307 tree name = TREE_PURPOSE (TREE_PURPOSE (t));
1310 const char *c = TREE_STRING_POINTER (name);
1311 if (strncmp (c, p + 1, len) == 0 && c[len] == '\0')
1315 for (t = inputs; t ; t = TREE_CHAIN (t), op++)
1317 tree name = TREE_PURPOSE (TREE_PURPOSE (t));
1320 const char *c = TREE_STRING_POINTER (name);
1321 if (strncmp (c, p + 1, len) == 0 && c[len] == '\0')
1327 error ("undefined named operand %qs", p + 1);
1331 /* Replace the name with the number. Unfortunately, not all libraries
1332 get the return value of sprintf correct, so search for the end of the
1333 generated string by hand. */
1334 sprintf (p, "%d", op);
1335 p = strchr (p, '\0');
1337 /* Verify the no extra buffer space assumption. */
1338 gcc_assert (p <= q);
1340 /* Shift the rest of the buffer down to fill the gap. */
1341 memmove (p, q + 1, strlen (q + 1) + 1);
1346 /* Generate RTL to evaluate the expression EXP. */
1349 expand_expr_stmt (tree exp)
1354 value = expand_expr (exp, const0_rtx, VOIDmode, 0);
1355 type = TREE_TYPE (exp);
1357 /* If all we do is reference a volatile value in memory,
1358 copy it to a register to be sure it is actually touched. */
1359 if (value && MEM_P (value) && TREE_THIS_VOLATILE (exp))
1361 if (TYPE_MODE (type) == VOIDmode)
1363 else if (TYPE_MODE (type) != BLKmode)
1364 value = copy_to_reg (value);
1367 rtx lab = gen_label_rtx ();
1369 /* Compare the value with itself to reference it. */
1370 emit_cmp_and_jump_insns (value, value, EQ,
1371 expand_expr (TYPE_SIZE (type),
1372 NULL_RTX, VOIDmode, 0),
1378 /* Free any temporaries used to evaluate this expression. */
1382 /* Warn if EXP contains any computations whose results are not used.
1383 Return 1 if a warning is printed; 0 otherwise. LOCUS is the
1384 (potential) location of the expression. */
1387 warn_if_unused_value (tree exp, location_t locus)
1390 if (TREE_USED (exp))
1393 /* Don't warn about void constructs. This includes casting to void,
1394 void function calls, and statement expressions with a final cast
1396 if (VOID_TYPE_P (TREE_TYPE (exp)))
1399 if (EXPR_HAS_LOCATION (exp))
1400 locus = EXPR_LOCATION (exp);
1402 switch (TREE_CODE (exp))
1404 case PREINCREMENT_EXPR:
1405 case POSTINCREMENT_EXPR:
1406 case PREDECREMENT_EXPR:
1407 case POSTDECREMENT_EXPR:
1412 case TRY_CATCH_EXPR:
1413 case WITH_CLEANUP_EXPR:
1418 /* For a binding, warn if no side effect within it. */
1419 exp = BIND_EXPR_BODY (exp);
1423 exp = TREE_OPERAND (exp, 0);
1426 case TRUTH_ORIF_EXPR:
1427 case TRUTH_ANDIF_EXPR:
1428 /* In && or ||, warn if 2nd operand has no side effect. */
1429 exp = TREE_OPERAND (exp, 1);
1433 if (TREE_NO_WARNING (exp))
1435 if (warn_if_unused_value (TREE_OPERAND (exp, 0), locus))
1437 /* Let people do `(foo (), 0)' without a warning. */
1438 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1440 exp = TREE_OPERAND (exp, 1);
1445 case NON_LVALUE_EXPR:
1446 /* Don't warn about conversions not explicit in the user's program. */
1447 if (TREE_NO_WARNING (exp))
1449 /* Assignment to a cast usually results in a cast of a modify.
1450 Don't complain about that. There can be an arbitrary number of
1451 casts before the modify, so we must loop until we find the first
1452 non-cast expression and then test to see if that is a modify. */
1454 tree tem = TREE_OPERAND (exp, 0);
1456 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1457 tem = TREE_OPERAND (tem, 0);
1459 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1460 || TREE_CODE (tem) == CALL_EXPR)
1466 /* Don't warn about automatic dereferencing of references, since
1467 the user cannot control it. */
1468 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1470 exp = TREE_OPERAND (exp, 0);
1476 /* Referencing a volatile value is a side effect, so don't warn. */
1477 if ((DECL_P (exp) || REFERENCE_CLASS_P (exp))
1478 && TREE_THIS_VOLATILE (exp))
1481 /* If this is an expression which has no operands, there is no value
1482 to be unused. There are no such language-independent codes,
1483 but front ends may define such. */
1484 if (EXPRESSION_CLASS_P (exp) && TREE_CODE_LENGTH (TREE_CODE (exp)) == 0)
1488 /* If this is an expression with side effects, don't warn. */
1489 if (TREE_SIDE_EFFECTS (exp))
1492 warning ("%Hvalue computed is not used", &locus);
1498 /* Generate RTL to return from the current function, with no value.
1499 (That is, we do not do anything about returning any value.) */
1502 expand_null_return (void)
1504 /* If this function was declared to return a value, but we
1505 didn't, clobber the return registers so that they are not
1506 propagated live to the rest of the function. */
1507 clobber_return_register ();
1509 expand_null_return_1 ();
1512 /* Generate RTL to return directly from the current function.
1513 (That is, we bypass any return value.) */
1516 expand_naked_return (void)
1520 clear_pending_stack_adjust ();
1521 do_pending_stack_adjust ();
1523 end_label = naked_return_label;
1525 end_label = naked_return_label = gen_label_rtx ();
1527 emit_jump (end_label);
1530 /* If the current function returns values in the most significant part
1531 of a register, shift return value VAL appropriately. The mode of
1532 the function's return type is known not to be BLKmode. */
1535 shift_return_value (rtx val)
1539 type = TREE_TYPE (DECL_RESULT (current_function_decl));
1540 if (targetm.calls.return_in_msb (type))
1543 HOST_WIDE_INT shift;
1545 target = DECL_RTL (DECL_RESULT (current_function_decl));
1546 shift = (GET_MODE_BITSIZE (GET_MODE (target))
1547 - BITS_PER_UNIT * int_size_in_bytes (type));
1549 val = expand_shift (LSHIFT_EXPR, GET_MODE (target),
1550 gen_lowpart (GET_MODE (target), val),
1551 build_int_cst (NULL_TREE, shift), target, 1);
1557 /* Generate RTL to return from the current function, with value VAL. */
1560 expand_value_return (rtx val)
1562 /* Copy the value to the return location
1563 unless it's already there. */
1565 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
1566 if (return_reg != val)
1568 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
1569 if (targetm.calls.promote_function_return (TREE_TYPE (current_function_decl)))
1571 int unsignedp = TYPE_UNSIGNED (type);
1572 enum machine_mode old_mode
1573 = DECL_MODE (DECL_RESULT (current_function_decl));
1574 enum machine_mode mode
1575 = promote_mode (type, old_mode, &unsignedp, 1);
1577 if (mode != old_mode)
1578 val = convert_modes (mode, old_mode, val, unsignedp);
1580 if (GET_CODE (return_reg) == PARALLEL)
1581 emit_group_load (return_reg, val, type, int_size_in_bytes (type));
1583 emit_move_insn (return_reg, val);
1586 expand_null_return_1 ();
1589 /* Output a return with no value. */
1592 expand_null_return_1 (void)
1596 clear_pending_stack_adjust ();
1597 do_pending_stack_adjust ();
1599 end_label = return_label;
1601 end_label = return_label = gen_label_rtx ();
1602 emit_jump (end_label);
1605 /* Generate RTL to evaluate the expression RETVAL and return it
1606 from the current function. */
1609 expand_return (tree retval)
1615 /* If function wants no value, give it none. */
1616 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
1618 expand_expr (retval, NULL_RTX, VOIDmode, 0);
1619 expand_null_return ();
1623 if (retval == error_mark_node)
1625 /* Treat this like a return of no value from a function that
1627 expand_null_return ();
1630 else if ((TREE_CODE (retval) == MODIFY_EXPR
1631 || TREE_CODE (retval) == INIT_EXPR)
1632 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
1633 retval_rhs = TREE_OPERAND (retval, 1);
1635 retval_rhs = retval;
1637 result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
1639 /* If we are returning the RESULT_DECL, then the value has already
1640 been stored into it, so we don't have to do anything special. */
1641 if (TREE_CODE (retval_rhs) == RESULT_DECL)
1642 expand_value_return (result_rtl);
1644 /* If the result is an aggregate that is being returned in one (or more)
1645 registers, load the registers here. The compiler currently can't handle
1646 copying a BLKmode value into registers. We could put this code in a
1647 more general area (for use by everyone instead of just function
1648 call/return), but until this feature is generally usable it is kept here
1649 (and in expand_call). */
1651 else if (retval_rhs != 0
1652 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
1653 && REG_P (result_rtl))
1656 unsigned HOST_WIDE_INT bitpos, xbitpos;
1657 unsigned HOST_WIDE_INT padding_correction = 0;
1658 unsigned HOST_WIDE_INT bytes
1659 = int_size_in_bytes (TREE_TYPE (retval_rhs));
1660 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
1661 unsigned int bitsize
1662 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), BITS_PER_WORD);
1663 rtx *result_pseudos = alloca (sizeof (rtx) * n_regs);
1664 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
1665 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
1666 enum machine_mode tmpmode, result_reg_mode;
1670 expand_null_return ();
1674 /* If the structure doesn't take up a whole number of words, see
1675 whether the register value should be padded on the left or on
1676 the right. Set PADDING_CORRECTION to the number of padding
1677 bits needed on the left side.
1679 In most ABIs, the structure will be returned at the least end of
1680 the register, which translates to right padding on little-endian
1681 targets and left padding on big-endian targets. The opposite
1682 holds if the structure is returned at the most significant
1683 end of the register. */
1684 if (bytes % UNITS_PER_WORD != 0
1685 && (targetm.calls.return_in_msb (TREE_TYPE (retval_rhs))
1687 : BYTES_BIG_ENDIAN))
1688 padding_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
1691 /* Copy the structure BITSIZE bits at a time. */
1692 for (bitpos = 0, xbitpos = padding_correction;
1693 bitpos < bytes * BITS_PER_UNIT;
1694 bitpos += bitsize, xbitpos += bitsize)
1696 /* We need a new destination pseudo each time xbitpos is
1697 on a word boundary and when xbitpos == padding_correction
1698 (the first time through). */
1699 if (xbitpos % BITS_PER_WORD == 0
1700 || xbitpos == padding_correction)
1702 /* Generate an appropriate register. */
1703 dst = gen_reg_rtx (word_mode);
1704 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
1706 /* Clear the destination before we move anything into it. */
1707 emit_move_insn (dst, CONST0_RTX (GET_MODE (dst)));
1710 /* We need a new source operand each time bitpos is on a word
1712 if (bitpos % BITS_PER_WORD == 0)
1713 src = operand_subword_force (result_val,
1714 bitpos / BITS_PER_WORD,
1717 /* Use bitpos for the source extraction (left justified) and
1718 xbitpos for the destination store (right justified). */
1719 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
1720 extract_bit_field (src, bitsize,
1721 bitpos % BITS_PER_WORD, 1,
1722 NULL_RTX, word_mode, word_mode));
1725 tmpmode = GET_MODE (result_rtl);
1726 if (tmpmode == BLKmode)
1728 /* Find the smallest integer mode large enough to hold the
1729 entire structure and use that mode instead of BLKmode
1730 on the USE insn for the return register. */
1731 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
1732 tmpmode != VOIDmode;
1733 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
1734 /* Have we found a large enough mode? */
1735 if (GET_MODE_SIZE (tmpmode) >= bytes)
1738 /* A suitable mode should have been found. */
1739 gcc_assert (tmpmode != VOIDmode);
1741 PUT_MODE (result_rtl, tmpmode);
1744 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
1745 result_reg_mode = word_mode;
1747 result_reg_mode = tmpmode;
1748 result_reg = gen_reg_rtx (result_reg_mode);
1750 for (i = 0; i < n_regs; i++)
1751 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
1754 if (tmpmode != result_reg_mode)
1755 result_reg = gen_lowpart (tmpmode, result_reg);
1757 expand_value_return (result_reg);
1759 else if (retval_rhs != 0
1760 && !VOID_TYPE_P (TREE_TYPE (retval_rhs))
1761 && (REG_P (result_rtl)
1762 || (GET_CODE (result_rtl) == PARALLEL)))
1764 /* Calculate the return value into a temporary (usually a pseudo
1766 tree ot = TREE_TYPE (DECL_RESULT (current_function_decl));
1767 tree nt = build_qualified_type (ot, TYPE_QUALS (ot) | TYPE_QUAL_CONST);
1769 val = assign_temp (nt, 0, 0, 1);
1770 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
1771 val = force_not_mem (val);
1772 /* Return the calculated value. */
1773 expand_value_return (shift_return_value (val));
1777 /* No hard reg used; calculate value into hard return reg. */
1778 expand_expr (retval, const0_rtx, VOIDmode, 0);
1779 expand_value_return (result_rtl);
1783 /* Given a pointer to a BLOCK node return nonzero if (and only if) the node
1784 in question represents the outermost pair of curly braces (i.e. the "body
1785 block") of a function or method.
1787 For any BLOCK node representing a "body block" of a function or method, the
1788 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
1789 represents the outermost (function) scope for the function or method (i.e.
1790 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
1791 *that* node in turn will point to the relevant FUNCTION_DECL node. */
1794 is_body_block (tree stmt)
1796 if (lang_hooks.no_body_blocks)
1799 if (TREE_CODE (stmt) == BLOCK)
1801 tree parent = BLOCK_SUPERCONTEXT (stmt);
1803 if (parent && TREE_CODE (parent) == BLOCK)
1805 tree grandparent = BLOCK_SUPERCONTEXT (parent);
1807 if (grandparent && TREE_CODE (grandparent) == FUNCTION_DECL)
1815 /* Emit code to restore vital registers at the beginning of a nonlocal goto
1818 expand_nl_goto_receiver (void)
1820 /* Clobber the FP when we get here, so we have to make sure it's
1821 marked as used by this function. */
1822 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
1824 /* Mark the static chain as clobbered here so life information
1825 doesn't get messed up for it. */
1826 emit_insn (gen_rtx_CLOBBER (VOIDmode, static_chain_rtx));
1828 #ifdef HAVE_nonlocal_goto
1829 if (! HAVE_nonlocal_goto)
1831 /* First adjust our frame pointer to its actual value. It was
1832 previously set to the start of the virtual area corresponding to
1833 the stacked variables when we branched here and now needs to be
1834 adjusted to the actual hardware fp value.
1836 Assignments are to virtual registers are converted by
1837 instantiate_virtual_regs into the corresponding assignment
1838 to the underlying register (fp in this case) that makes
1839 the original assignment true.
1840 So the following insn will actually be
1841 decrementing fp by STARTING_FRAME_OFFSET. */
1842 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
1844 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
1845 if (fixed_regs[ARG_POINTER_REGNUM])
1847 #ifdef ELIMINABLE_REGS
1848 /* If the argument pointer can be eliminated in favor of the
1849 frame pointer, we don't need to restore it. We assume here
1850 that if such an elimination is present, it can always be used.
1851 This is the case on all known machines; if we don't make this
1852 assumption, we do unnecessary saving on many machines. */
1853 static const struct elims {const int from, to;} elim_regs[] = ELIMINABLE_REGS;
1856 for (i = 0; i < ARRAY_SIZE (elim_regs); i++)
1857 if (elim_regs[i].from == ARG_POINTER_REGNUM
1858 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
1861 if (i == ARRAY_SIZE (elim_regs))
1864 /* Now restore our arg pointer from the address at which it
1865 was saved in our stack frame. */
1866 emit_move_insn (virtual_incoming_args_rtx,
1867 copy_to_reg (get_arg_pointer_save_area (cfun)));
1872 #ifdef HAVE_nonlocal_goto_receiver
1873 if (HAVE_nonlocal_goto_receiver)
1874 emit_insn (gen_nonlocal_goto_receiver ());
1877 /* @@@ This is a kludge. Not all machine descriptions define a blockage
1878 insn, but we must not allow the code we just generated to be reordered
1879 by scheduling. Specifically, the update of the frame pointer must
1880 happen immediately, not later. So emit an ASM_INPUT to act as blockage
1882 emit_insn (gen_rtx_ASM_INPUT (VOIDmode, ""));
1885 /* Generate RTL for the automatic variable declaration DECL.
1886 (Other kinds of declarations are simply ignored if seen here.) */
1889 expand_decl (tree decl)
1893 type = TREE_TYPE (decl);
1895 /* For a CONST_DECL, set mode, alignment, and sizes from those of the
1896 type in case this node is used in a reference. */
1897 if (TREE_CODE (decl) == CONST_DECL)
1899 DECL_MODE (decl) = TYPE_MODE (type);
1900 DECL_ALIGN (decl) = TYPE_ALIGN (type);
1901 DECL_SIZE (decl) = TYPE_SIZE (type);
1902 DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (type);
1906 /* Otherwise, only automatic variables need any expansion done. Static and
1907 external variables, and external functions, will be handled by
1908 `assemble_variable' (called from finish_decl). TYPE_DECL requires
1909 nothing. PARM_DECLs are handled in `assign_parms'. */
1910 if (TREE_CODE (decl) != VAR_DECL)
1913 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
1916 /* Create the RTL representation for the variable. */
1918 if (type == error_mark_node)
1919 SET_DECL_RTL (decl, gen_rtx_MEM (BLKmode, const0_rtx));
1921 else if (DECL_SIZE (decl) == 0)
1922 /* Variable with incomplete type. */
1925 if (DECL_INITIAL (decl) == 0)
1926 /* Error message was already done; now avoid a crash. */
1927 x = gen_rtx_MEM (BLKmode, const0_rtx);
1929 /* An initializer is going to decide the size of this array.
1930 Until we know the size, represent its address with a reg. */
1931 x = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
1933 set_mem_attributes (x, decl, 1);
1934 SET_DECL_RTL (decl, x);
1936 else if (use_register_for_decl (decl))
1938 /* Automatic variable that can go in a register. */
1939 int unsignedp = TYPE_UNSIGNED (type);
1940 enum machine_mode reg_mode
1941 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
1943 SET_DECL_RTL (decl, gen_reg_rtx (reg_mode));
1945 /* Note if the object is a user variable. */
1946 if (!DECL_ARTIFICIAL (decl))
1948 mark_user_reg (DECL_RTL (decl));
1950 /* Trust user variables which have a pointer type to really
1951 be pointers. Do not trust compiler generated temporaries
1952 as our type system is totally busted as it relates to
1953 pointer arithmetic which translates into lots of compiler
1954 generated objects with pointer types, but which are not really
1956 if (POINTER_TYPE_P (type))
1957 mark_reg_pointer (DECL_RTL (decl),
1958 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
1962 else if (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST
1963 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
1964 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl),
1965 STACK_CHECK_MAX_VAR_SIZE)))
1967 /* Variable of fixed size that goes on the stack. */
1972 /* If we previously made RTL for this decl, it must be an array
1973 whose size was determined by the initializer.
1974 The old address was a register; set that register now
1975 to the proper address. */
1976 if (DECL_RTL_SET_P (decl))
1978 gcc_assert (MEM_P (DECL_RTL (decl)));
1979 gcc_assert (REG_P (XEXP (DECL_RTL (decl), 0)));
1980 oldaddr = XEXP (DECL_RTL (decl), 0);
1983 /* Set alignment we actually gave this decl. */
1984 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
1985 : GET_MODE_BITSIZE (DECL_MODE (decl)));
1986 DECL_USER_ALIGN (decl) = 0;
1988 x = assign_temp (decl, 1, 1, 1);
1989 set_mem_attributes (x, decl, 1);
1990 SET_DECL_RTL (decl, x);
1994 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
1995 if (addr != oldaddr)
1996 emit_move_insn (oldaddr, addr);
2000 /* Dynamic-size object: must push space on the stack. */
2002 rtx address, size, x;
2004 /* Record the stack pointer on entry to block, if have
2005 not already done so. */
2006 do_pending_stack_adjust ();
2008 /* Compute the variable's size, in bytes. This will expand any
2009 needed SAVE_EXPRs for the first time. */
2010 size = expand_expr (DECL_SIZE_UNIT (decl), NULL_RTX, VOIDmode, 0);
2013 /* Allocate space on the stack for the variable. Note that
2014 DECL_ALIGN says how the variable is to be aligned and we
2015 cannot use it to conclude anything about the alignment of
2017 address = allocate_dynamic_stack_space (size, NULL_RTX,
2018 TYPE_ALIGN (TREE_TYPE (decl)));
2020 /* Reference the variable indirect through that rtx. */
2021 x = gen_rtx_MEM (DECL_MODE (decl), address);
2022 set_mem_attributes (x, decl, 1);
2023 SET_DECL_RTL (decl, x);
2026 /* Indicate the alignment we actually gave this variable. */
2027 #ifdef STACK_BOUNDARY
2028 DECL_ALIGN (decl) = STACK_BOUNDARY;
2030 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
2032 DECL_USER_ALIGN (decl) = 0;
2036 /* Emit code to save the current value of stack. */
2038 expand_stack_save (void)
2042 do_pending_stack_adjust ();
2043 emit_stack_save (SAVE_BLOCK, &ret, NULL_RTX);
2047 /* Emit code to restore the current value of stack. */
2049 expand_stack_restore (tree var)
2051 rtx sa = DECL_RTL (var);
2053 emit_stack_restore (SAVE_BLOCK, sa, NULL_RTX);
2056 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
2057 DECL_ELTS is the list of elements that belong to DECL's type.
2058 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
2061 expand_anon_union_decl (tree decl, tree cleanup ATTRIBUTE_UNUSED,
2067 /* If any of the elements are addressable, so is the entire union. */
2068 for (t = decl_elts; t; t = TREE_CHAIN (t))
2069 if (TREE_ADDRESSABLE (TREE_VALUE (t)))
2071 TREE_ADDRESSABLE (decl) = 1;
2076 x = DECL_RTL (decl);
2078 /* Go through the elements, assigning RTL to each. */
2079 for (t = decl_elts; t; t = TREE_CHAIN (t))
2081 tree decl_elt = TREE_VALUE (t);
2082 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
2085 /* If any of the elements are addressable, so is the entire
2087 if (TREE_USED (decl_elt))
2088 TREE_USED (decl) = 1;
2090 /* Propagate the union's alignment to the elements. */
2091 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
2092 DECL_USER_ALIGN (decl_elt) = DECL_USER_ALIGN (decl);
2094 /* If the element has BLKmode and the union doesn't, the union is
2095 aligned such that the element doesn't need to have BLKmode, so
2096 change the element's mode to the appropriate one for its size. */
2097 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
2098 DECL_MODE (decl_elt) = mode
2099 = mode_for_size_tree (DECL_SIZE (decl_elt), MODE_INT, 1);
2101 if (mode == GET_MODE (x))
2104 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
2105 instead create a new MEM rtx with the proper mode. */
2106 decl_rtl = adjust_address_nv (x, mode, 0);
2109 gcc_assert (REG_P (x));
2110 decl_rtl = gen_lowpart_SUBREG (mode, x);
2112 SET_DECL_RTL (decl_elt, decl_rtl);
2116 /* Do the insertion of a case label into case_list. The labels are
2117 fed to us in descending order from the sorted vector of case labels used
2118 in the tree part of the middle end. So the list we construct is
2119 sorted in ascending order. The bounds on the case range, LOW and HIGH,
2120 are converted to case's index type TYPE. */
2122 static struct case_node *
2123 add_case_node (struct case_node *head, tree type, tree low, tree high,
2126 tree min_value, max_value;
2127 struct case_node *r;
2129 gcc_assert (TREE_CODE (low) == INTEGER_CST);
2130 gcc_assert (!high || TREE_CODE (high) == INTEGER_CST);
2132 min_value = TYPE_MIN_VALUE (type);
2133 max_value = TYPE_MAX_VALUE (type);
2135 /* If there's no HIGH value, then this is not a case range; it's
2136 just a simple case label. But that's just a degenerate case
2138 If the bounds are equal, turn this into the one-value case. */
2139 if (!high || tree_int_cst_equal (low, high))
2141 /* If the simple case value is unreachable, ignore it. */
2142 if ((TREE_CODE (min_value) == INTEGER_CST
2143 && tree_int_cst_compare (low, min_value) < 0)
2144 || (TREE_CODE (max_value) == INTEGER_CST
2145 && tree_int_cst_compare (low, max_value) > 0))
2147 low = fold_convert (type, low);
2152 /* If the entire case range is unreachable, ignore it. */
2153 if ((TREE_CODE (min_value) == INTEGER_CST
2154 && tree_int_cst_compare (high, min_value) < 0)
2155 || (TREE_CODE (max_value) == INTEGER_CST
2156 && tree_int_cst_compare (low, max_value) > 0))
2159 /* If the lower bound is less than the index type's minimum
2160 value, truncate the range bounds. */
2161 if (TREE_CODE (min_value) == INTEGER_CST
2162 && tree_int_cst_compare (low, min_value) < 0)
2164 low = fold_convert (type, low);
2166 /* If the upper bound is greater than the index type's maximum
2167 value, truncate the range bounds. */
2168 if (TREE_CODE (max_value) == INTEGER_CST
2169 && tree_int_cst_compare (high, max_value) > 0)
2171 high = fold_convert (type, high);
2175 /* Add this label to the chain. */
2176 r = ggc_alloc (sizeof (struct case_node));
2179 r->code_label = label;
2180 r->parent = r->left = NULL;
2185 /* Maximum number of case bit tests. */
2186 #define MAX_CASE_BIT_TESTS 3
2188 /* By default, enable case bit tests on targets with ashlsi3. */
2189 #ifndef CASE_USE_BIT_TESTS
2190 #define CASE_USE_BIT_TESTS (ashl_optab->handlers[word_mode].insn_code \
2191 != CODE_FOR_nothing)
2195 /* A case_bit_test represents a set of case nodes that may be
2196 selected from using a bit-wise comparison. HI and LO hold
2197 the integer to be tested against, LABEL contains the label
2198 to jump to upon success and BITS counts the number of case
2199 nodes handled by this test, typically the number of bits
2202 struct case_bit_test
2210 /* Determine whether "1 << x" is relatively cheap in word_mode. */
2213 bool lshift_cheap_p (void)
2215 static bool init = false;
2216 static bool cheap = true;
2220 rtx reg = gen_rtx_REG (word_mode, 10000);
2221 int cost = rtx_cost (gen_rtx_ASHIFT (word_mode, const1_rtx, reg), SET);
2222 cheap = cost < COSTS_N_INSNS (3);
2229 /* Comparison function for qsort to order bit tests by decreasing
2230 number of case nodes, i.e. the node with the most cases gets
2234 case_bit_test_cmp (const void *p1, const void *p2)
2236 const struct case_bit_test *d1 = p1;
2237 const struct case_bit_test *d2 = p2;
2239 return d2->bits - d1->bits;
2242 /* Expand a switch statement by a short sequence of bit-wise
2243 comparisons. "switch(x)" is effectively converted into
2244 "if ((1 << (x-MINVAL)) & CST)" where CST and MINVAL are
2247 INDEX_EXPR is the value being switched on, which is of
2248 type INDEX_TYPE. MINVAL is the lowest case value of in
2249 the case nodes, of INDEX_TYPE type, and RANGE is highest
2250 value minus MINVAL, also of type INDEX_TYPE. NODES is
2251 the set of case nodes, and DEFAULT_LABEL is the label to
2252 branch to should none of the cases match.
2254 There *MUST* be MAX_CASE_BIT_TESTS or less unique case
2258 emit_case_bit_tests (tree index_type, tree index_expr, tree minval,
2259 tree range, case_node_ptr nodes, rtx default_label)
2261 struct case_bit_test test[MAX_CASE_BIT_TESTS];
2262 enum machine_mode mode;
2263 rtx expr, index, label;
2264 unsigned int i,j,lo,hi;
2265 struct case_node *n;
2269 for (n = nodes; n; n = n->right)
2271 label = label_rtx (n->code_label);
2272 for (i = 0; i < count; i++)
2273 if (label == test[i].label)
2278 gcc_assert (count < MAX_CASE_BIT_TESTS);
2281 test[i].label = label;
2288 lo = tree_low_cst (fold (build2 (MINUS_EXPR, index_type,
2289 n->low, minval)), 1);
2290 hi = tree_low_cst (fold (build2 (MINUS_EXPR, index_type,
2291 n->high, minval)), 1);
2292 for (j = lo; j <= hi; j++)
2293 if (j >= HOST_BITS_PER_WIDE_INT)
2294 test[i].hi |= (HOST_WIDE_INT) 1 << (j - HOST_BITS_PER_INT);
2296 test[i].lo |= (HOST_WIDE_INT) 1 << j;
2299 qsort (test, count, sizeof(*test), case_bit_test_cmp);
2301 index_expr = fold (build2 (MINUS_EXPR, index_type,
2302 convert (index_type, index_expr),
2303 convert (index_type, minval)));
2304 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
2305 do_pending_stack_adjust ();
2307 mode = TYPE_MODE (index_type);
2308 expr = expand_expr (range, NULL_RTX, VOIDmode, 0);
2309 emit_cmp_and_jump_insns (index, expr, GTU, NULL_RTX, mode, 1,
2312 index = convert_to_mode (word_mode, index, 0);
2313 index = expand_binop (word_mode, ashl_optab, const1_rtx,
2314 index, NULL_RTX, 1, OPTAB_WIDEN);
2316 for (i = 0; i < count; i++)
2318 expr = immed_double_const (test[i].lo, test[i].hi, word_mode);
2319 expr = expand_binop (word_mode, and_optab, index, expr,
2320 NULL_RTX, 1, OPTAB_WIDEN);
2321 emit_cmp_and_jump_insns (expr, const0_rtx, NE, NULL_RTX,
2322 word_mode, 1, test[i].label);
2325 emit_jump (default_label);
2329 #define HAVE_casesi 0
2332 #ifndef HAVE_tablejump
2333 #define HAVE_tablejump 0
2336 /* Terminate a case (Pascal) or switch (C) statement
2337 in which ORIG_INDEX is the expression to be tested.
2338 If ORIG_TYPE is not NULL, it is the original ORIG_INDEX
2339 type as given in the source before any compiler conversions.
2340 Generate the code to test it and jump to the right place. */
2343 expand_case (tree exp)
2345 tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE;
2346 rtx default_label = 0;
2347 struct case_node *n, *m;
2348 unsigned int count, uniq;
2354 rtx before_case, end, lab;
2356 tree vec = SWITCH_LABELS (exp);
2357 tree orig_type = TREE_TYPE (exp);
2358 tree index_expr = SWITCH_COND (exp);
2359 tree index_type = TREE_TYPE (index_expr);
2360 int unsignedp = TYPE_UNSIGNED (index_type);
2362 /* The insn after which the case dispatch should finally
2363 be emitted. Zero for a dummy. */
2366 /* A list of case labels; it is first built as a list and it may then
2367 be rearranged into a nearly balanced binary tree. */
2368 struct case_node *case_list = 0;
2370 /* Label to jump to if no case matches. */
2371 tree default_label_decl = 0;
2373 /* The switch body is lowered in gimplify.c, we should never have
2374 switches with a non-NULL SWITCH_BODY here. */
2375 gcc_assert (!SWITCH_BODY (exp));
2376 gcc_assert (SWITCH_LABELS (exp));
2378 do_pending_stack_adjust ();
2380 /* An ERROR_MARK occurs for various reasons including invalid data type. */
2381 if (index_type != error_mark_node)
2383 for (i = TREE_VEC_LENGTH (vec); --i >= 0; )
2385 tree elt = TREE_VEC_ELT (vec, i);
2387 /* Handle default labels specially. */
2388 if (!CASE_HIGH (elt) && !CASE_LOW (elt))
2390 gcc_assert (!default_label_decl);
2391 default_label_decl = CASE_LABEL (elt);
2394 case_list = add_case_node (case_list, index_type,
2395 CASE_LOW (elt), CASE_HIGH (elt),
2400 /* Make sure start points to something that won't need any
2401 transformation before the end of this function. */
2402 start = get_last_insn ();
2403 if (! NOTE_P (start))
2405 emit_note (NOTE_INSN_DELETED);
2406 start = get_last_insn ();
2409 /* If we don't have a default-label, create one here,
2410 after the body of the switch. */
2411 if (default_label_decl == 0)
2414 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
2415 expand_label (default_label_decl);
2417 default_label = label_rtx (default_label_decl);
2419 before_case = get_last_insn ();
2421 /* Get upper and lower bounds of case values.
2422 Also convert all the case values to the index expr's data type. */
2426 for (n = case_list; n; n = n->right)
2428 /* Count the elements and track the largest and smallest
2429 of them (treating them as signed even if they are not). */
2437 if (INT_CST_LT (n->low, minval))
2439 if (INT_CST_LT (maxval, n->high))
2442 /* A range counts double, since it requires two compares. */
2443 if (! tree_int_cst_equal (n->low, n->high))
2446 /* Count the number of unique case node targets. */
2448 lab = label_rtx (n->code_label);
2449 for (m = case_list; m != n; m = m->right)
2450 if (label_rtx (m->code_label) == lab)
2457 /* Compute span of values. */
2459 range = fold (build2 (MINUS_EXPR, index_type, maxval, minval));
2463 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
2464 emit_jump (default_label);
2467 /* Try implementing this switch statement by a short sequence of
2468 bit-wise comparisons. However, we let the binary-tree case
2469 below handle constant index expressions. */
2470 else if (CASE_USE_BIT_TESTS
2471 && ! TREE_CONSTANT (index_expr)
2472 && compare_tree_int (range, GET_MODE_BITSIZE (word_mode)) < 0
2473 && compare_tree_int (range, 0) > 0
2474 && lshift_cheap_p ()
2475 && ((uniq == 1 && count >= 3)
2476 || (uniq == 2 && count >= 5)
2477 || (uniq == 3 && count >= 6)))
2479 /* Optimize the case where all the case values fit in a
2480 word without having to subtract MINVAL. In this case,
2481 we can optimize away the subtraction. */
2482 if (compare_tree_int (minval, 0) > 0
2483 && compare_tree_int (maxval, GET_MODE_BITSIZE (word_mode)) < 0)
2485 minval = integer_zero_node;
2488 emit_case_bit_tests (index_type, index_expr, minval, range,
2489 case_list, default_label);
2492 /* If range of values is much bigger than number of values,
2493 make a sequence of conditional branches instead of a dispatch.
2494 If the switch-index is a constant, do it this way
2495 because we can optimize it. */
2497 else if (count < case_values_threshold ()
2498 || compare_tree_int (range,
2499 (optimize_size ? 3 : 10) * count) > 0
2500 /* RANGE may be signed, and really large ranges will show up
2501 as negative numbers. */
2502 || compare_tree_int (range, 0) < 0
2503 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
2506 || TREE_CONSTANT (index_expr)
2507 /* If neither casesi or tablejump is available, we can
2508 only go this way. */
2509 || (!HAVE_casesi && !HAVE_tablejump))
2511 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
2513 /* If the index is a short or char that we do not have
2514 an insn to handle comparisons directly, convert it to
2515 a full integer now, rather than letting each comparison
2516 generate the conversion. */
2518 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
2519 && ! have_insn_for (COMPARE, GET_MODE (index)))
2521 enum machine_mode wider_mode;
2522 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
2523 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
2524 if (have_insn_for (COMPARE, wider_mode))
2526 index = convert_to_mode (wider_mode, index, unsignedp);
2531 do_pending_stack_adjust ();
2534 index = copy_to_reg (index);
2535 if (GET_CODE (index) == CONST_INT
2536 || TREE_CODE (index_expr) == INTEGER_CST)
2538 /* Make a tree node with the proper constant value
2539 if we don't already have one. */
2540 if (TREE_CODE (index_expr) != INTEGER_CST)
2543 = build_int_cst_wide (NULL_TREE, INTVAL (index),
2544 unsignedp || INTVAL (index) >= 0
2546 index_expr = convert (index_type, index_expr);
2549 /* For constant index expressions we need only
2550 issue an unconditional branch to the appropriate
2551 target code. The job of removing any unreachable
2552 code is left to the optimization phase if the
2553 "-O" option is specified. */
2554 for (n = case_list; n; n = n->right)
2555 if (! tree_int_cst_lt (index_expr, n->low)
2556 && ! tree_int_cst_lt (n->high, index_expr))
2560 emit_jump (label_rtx (n->code_label));
2562 emit_jump (default_label);
2566 /* If the index expression is not constant we generate
2567 a binary decision tree to select the appropriate
2568 target code. This is done as follows:
2570 The list of cases is rearranged into a binary tree,
2571 nearly optimal assuming equal probability for each case.
2573 The tree is transformed into RTL, eliminating
2574 redundant test conditions at the same time.
2576 If program flow could reach the end of the
2577 decision tree an unconditional jump to the
2578 default code is emitted. */
2581 = (TREE_CODE (orig_type) != ENUMERAL_TYPE
2582 && estimate_case_costs (case_list));
2583 balance_case_nodes (&case_list, NULL);
2584 emit_case_nodes (index, case_list, default_label, index_type);
2585 emit_jump (default_label);
2590 table_label = gen_label_rtx ();
2591 if (! try_casesi (index_type, index_expr, minval, range,
2592 table_label, default_label))
2595 index_type = integer_type_node;
2597 /* Index jumptables from zero for suitable values of
2598 minval to avoid a subtraction. */
2600 && compare_tree_int (minval, 0) > 0
2601 && compare_tree_int (minval, 3) < 0)
2603 minval = integer_zero_node;
2607 ok = try_tablejump (index_type, index_expr, minval, range,
2608 table_label, default_label);
2612 /* Get table of labels to jump to, in order of case index. */
2614 ncases = tree_low_cst (range, 0) + 1;
2615 labelvec = alloca (ncases * sizeof (rtx));
2616 memset (labelvec, 0, ncases * sizeof (rtx));
2618 for (n = case_list; n; n = n->right)
2620 /* Compute the low and high bounds relative to the minimum
2621 value since that should fit in a HOST_WIDE_INT while the
2622 actual values may not. */
2624 = tree_low_cst (fold (build2 (MINUS_EXPR, index_type,
2625 n->low, minval)), 1);
2626 HOST_WIDE_INT i_high
2627 = tree_low_cst (fold (build2 (MINUS_EXPR, index_type,
2628 n->high, minval)), 1);
2631 for (i = i_low; i <= i_high; i ++)
2633 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
2636 /* Fill in the gaps with the default. */
2637 for (i = 0; i < ncases; i++)
2638 if (labelvec[i] == 0)
2639 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
2641 /* Output the table. */
2642 emit_label (table_label);
2644 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
2645 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
2646 gen_rtx_LABEL_REF (Pmode, table_label),
2647 gen_rtvec_v (ncases, labelvec),
2648 const0_rtx, const0_rtx));
2650 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
2651 gen_rtvec_v (ncases, labelvec)));
2653 /* If the case insn drops through the table,
2654 after the table we must jump to the default-label.
2655 Otherwise record no drop-through after the table. */
2656 #ifdef CASE_DROPS_THROUGH
2657 emit_jump (default_label);
2663 before_case = NEXT_INSN (before_case);
2664 end = get_last_insn ();
2665 fail = squeeze_notes (&before_case, &end);
2667 reorder_insns (before_case, end, start);
2673 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
2676 do_jump_if_equal (rtx op1, rtx op2, rtx label, int unsignedp)
2678 if (GET_CODE (op1) == CONST_INT && GET_CODE (op2) == CONST_INT)
2684 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX,
2685 (GET_MODE (op1) == VOIDmode
2686 ? GET_MODE (op2) : GET_MODE (op1)),
2690 /* Not all case values are encountered equally. This function
2691 uses a heuristic to weight case labels, in cases where that
2692 looks like a reasonable thing to do.
2694 Right now, all we try to guess is text, and we establish the
2697 chars above space: 16
2706 If we find any cases in the switch that are not either -1 or in the range
2707 of valid ASCII characters, or are control characters other than those
2708 commonly used with "\", don't treat this switch scanning text.
2710 Return 1 if these nodes are suitable for cost estimation, otherwise
2714 estimate_case_costs (case_node_ptr node)
2716 tree min_ascii = integer_minus_one_node;
2717 tree max_ascii = convert (TREE_TYPE (node->high),
2718 build_int_cst (NULL_TREE, 127));
2722 /* If we haven't already made the cost table, make it now. Note that the
2723 lower bound of the table is -1, not zero. */
2725 if (! cost_table_initialized)
2727 cost_table_initialized = 1;
2729 for (i = 0; i < 128; i++)
2732 COST_TABLE (i) = 16;
2733 else if (ISPUNCT (i))
2735 else if (ISCNTRL (i))
2736 COST_TABLE (i) = -1;
2739 COST_TABLE (' ') = 8;
2740 COST_TABLE ('\t') = 4;
2741 COST_TABLE ('\0') = 4;
2742 COST_TABLE ('\n') = 2;
2743 COST_TABLE ('\f') = 1;
2744 COST_TABLE ('\v') = 1;
2745 COST_TABLE ('\b') = 1;
2748 /* See if all the case expressions look like text. It is text if the
2749 constant is >= -1 and the highest constant is <= 127. Do all comparisons
2750 as signed arithmetic since we don't want to ever access cost_table with a
2751 value less than -1. Also check that none of the constants in a range
2752 are strange control characters. */
2754 for (n = node; n; n = n->right)
2756 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
2759 for (i = (HOST_WIDE_INT) TREE_INT_CST_LOW (n->low);
2760 i <= (HOST_WIDE_INT) TREE_INT_CST_LOW (n->high); i++)
2761 if (COST_TABLE (i) < 0)
2765 /* All interesting values are within the range of interesting
2766 ASCII characters. */
2770 /* Take an ordered list of case nodes
2771 and transform them into a near optimal binary tree,
2772 on the assumption that any target code selection value is as
2773 likely as any other.
2775 The transformation is performed by splitting the ordered
2776 list into two equal sections plus a pivot. The parts are
2777 then attached to the pivot as left and right branches. Each
2778 branch is then transformed recursively. */
2781 balance_case_nodes (case_node_ptr *head, case_node_ptr parent)
2794 /* Count the number of entries on branch. Also count the ranges. */
2798 if (!tree_int_cst_equal (np->low, np->high))
2802 cost += COST_TABLE (TREE_INT_CST_LOW (np->high));
2806 cost += COST_TABLE (TREE_INT_CST_LOW (np->low));
2814 /* Split this list if it is long enough for that to help. */
2819 /* Find the place in the list that bisects the list's total cost,
2820 Here I gets half the total cost. */
2825 /* Skip nodes while their cost does not reach that amount. */
2826 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
2827 i -= COST_TABLE (TREE_INT_CST_LOW ((*npp)->high));
2828 i -= COST_TABLE (TREE_INT_CST_LOW ((*npp)->low));
2831 npp = &(*npp)->right;
2836 /* Leave this branch lopsided, but optimize left-hand
2837 side and fill in `parent' fields for right-hand side. */
2839 np->parent = parent;
2840 balance_case_nodes (&np->left, np);
2841 for (; np->right; np = np->right)
2842 np->right->parent = np;
2846 /* If there are just three nodes, split at the middle one. */
2848 npp = &(*npp)->right;
2851 /* Find the place in the list that bisects the list's total cost,
2852 where ranges count as 2.
2853 Here I gets half the total cost. */
2854 i = (i + ranges + 1) / 2;
2857 /* Skip nodes while their cost does not reach that amount. */
2858 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
2863 npp = &(*npp)->right;
2868 np->parent = parent;
2871 /* Optimize each of the two split parts. */
2872 balance_case_nodes (&np->left, np);
2873 balance_case_nodes (&np->right, np);
2877 /* Else leave this branch as one level,
2878 but fill in `parent' fields. */
2880 np->parent = parent;
2881 for (; np->right; np = np->right)
2882 np->right->parent = np;
2887 /* Search the parent sections of the case node tree
2888 to see if a test for the lower bound of NODE would be redundant.
2889 INDEX_TYPE is the type of the index expression.
2891 The instructions to generate the case decision tree are
2892 output in the same order as nodes are processed so it is
2893 known that if a parent node checks the range of the current
2894 node minus one that the current node is bounded at its lower
2895 span. Thus the test would be redundant. */
2898 node_has_low_bound (case_node_ptr node, tree index_type)
2901 case_node_ptr pnode;
2903 /* If the lower bound of this node is the lowest value in the index type,
2904 we need not test it. */
2906 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
2909 /* If this node has a left branch, the value at the left must be less
2910 than that at this node, so it cannot be bounded at the bottom and
2911 we need not bother testing any further. */
2916 low_minus_one = fold (build2 (MINUS_EXPR, TREE_TYPE (node->low),
2917 node->low, integer_one_node));
2919 /* If the subtraction above overflowed, we can't verify anything.
2920 Otherwise, look for a parent that tests our value - 1. */
2922 if (! tree_int_cst_lt (low_minus_one, node->low))
2925 for (pnode = node->parent; pnode; pnode = pnode->parent)
2926 if (tree_int_cst_equal (low_minus_one, pnode->high))
2932 /* Search the parent sections of the case node tree
2933 to see if a test for the upper bound of NODE would be redundant.
2934 INDEX_TYPE is the type of the index expression.
2936 The instructions to generate the case decision tree are
2937 output in the same order as nodes are processed so it is
2938 known that if a parent node checks the range of the current
2939 node plus one that the current node is bounded at its upper
2940 span. Thus the test would be redundant. */
2943 node_has_high_bound (case_node_ptr node, tree index_type)
2946 case_node_ptr pnode;
2948 /* If there is no upper bound, obviously no test is needed. */
2950 if (TYPE_MAX_VALUE (index_type) == NULL)
2953 /* If the upper bound of this node is the highest value in the type
2954 of the index expression, we need not test against it. */
2956 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
2959 /* If this node has a right branch, the value at the right must be greater
2960 than that at this node, so it cannot be bounded at the top and
2961 we need not bother testing any further. */
2966 high_plus_one = fold (build2 (PLUS_EXPR, TREE_TYPE (node->high),
2967 node->high, integer_one_node));
2969 /* If the addition above overflowed, we can't verify anything.
2970 Otherwise, look for a parent that tests our value + 1. */
2972 if (! tree_int_cst_lt (node->high, high_plus_one))
2975 for (pnode = node->parent; pnode; pnode = pnode->parent)
2976 if (tree_int_cst_equal (high_plus_one, pnode->low))
2982 /* Search the parent sections of the
2983 case node tree to see if both tests for the upper and lower
2984 bounds of NODE would be redundant. */
2987 node_is_bounded (case_node_ptr node, tree index_type)
2989 return (node_has_low_bound (node, index_type)
2990 && node_has_high_bound (node, index_type));
2993 /* Emit step-by-step code to select a case for the value of INDEX.
2994 The thus generated decision tree follows the form of the
2995 case-node binary tree NODE, whose nodes represent test conditions.
2996 INDEX_TYPE is the type of the index of the switch.
2998 Care is taken to prune redundant tests from the decision tree
2999 by detecting any boundary conditions already checked by
3000 emitted rtx. (See node_has_high_bound, node_has_low_bound
3001 and node_is_bounded, above.)
3003 Where the test conditions can be shown to be redundant we emit
3004 an unconditional jump to the target code. As a further
3005 optimization, the subordinates of a tree node are examined to
3006 check for bounded nodes. In this case conditional and/or
3007 unconditional jumps as a result of the boundary check for the
3008 current node are arranged to target the subordinates associated
3009 code for out of bound conditions on the current node.
3011 We can assume that when control reaches the code generated here,
3012 the index value has already been compared with the parents
3013 of this node, and determined to be on the same side of each parent
3014 as this node is. Thus, if this node tests for the value 51,
3015 and a parent tested for 52, we don't need to consider
3016 the possibility of a value greater than 51. If another parent
3017 tests for the value 50, then this node need not test anything. */
3020 emit_case_nodes (rtx index, case_node_ptr node, rtx default_label,
3023 /* If INDEX has an unsigned type, we must make unsigned branches. */
3024 int unsignedp = TYPE_UNSIGNED (index_type);
3025 enum machine_mode mode = GET_MODE (index);
3026 enum machine_mode imode = TYPE_MODE (index_type);
3028 /* See if our parents have already tested everything for us.
3029 If they have, emit an unconditional jump for this node. */
3030 if (node_is_bounded (node, index_type))
3031 emit_jump (label_rtx (node->code_label));
3033 else if (tree_int_cst_equal (node->low, node->high))
3035 /* Node is single valued. First see if the index expression matches
3036 this node and then check our children, if any. */
3038 do_jump_if_equal (index,
3039 convert_modes (mode, imode,
3040 expand_expr (node->low, NULL_RTX,
3043 label_rtx (node->code_label), unsignedp);
3045 if (node->right != 0 && node->left != 0)
3047 /* This node has children on both sides.
3048 Dispatch to one side or the other
3049 by comparing the index value with this node's value.
3050 If one subtree is bounded, check that one first,
3051 so we can avoid real branches in the tree. */
3053 if (node_is_bounded (node->right, index_type))
3055 emit_cmp_and_jump_insns (index,
3058 expand_expr (node->high, NULL_RTX,
3061 GT, NULL_RTX, mode, unsignedp,
3062 label_rtx (node->right->code_label));
3063 emit_case_nodes (index, node->left, default_label, index_type);
3066 else if (node_is_bounded (node->left, index_type))
3068 emit_cmp_and_jump_insns (index,
3071 expand_expr (node->high, NULL_RTX,
3074 LT, NULL_RTX, mode, unsignedp,
3075 label_rtx (node->left->code_label));
3076 emit_case_nodes (index, node->right, default_label, index_type);
3079 /* If both children are single-valued cases with no
3080 children, finish up all the work. This way, we can save
3081 one ordered comparison. */
3082 else if (tree_int_cst_equal (node->right->low, node->right->high)
3083 && node->right->left == 0
3084 && node->right->right == 0
3085 && tree_int_cst_equal (node->left->low, node->left->high)
3086 && node->left->left == 0
3087 && node->left->right == 0)
3089 /* Neither node is bounded. First distinguish the two sides;
3090 then emit the code for one side at a time. */
3092 /* See if the value matches what the right hand side
3094 do_jump_if_equal (index,
3095 convert_modes (mode, imode,
3096 expand_expr (node->right->low,
3100 label_rtx (node->right->code_label),
3103 /* See if the value matches what the left hand side
3105 do_jump_if_equal (index,
3106 convert_modes (mode, imode,
3107 expand_expr (node->left->low,
3111 label_rtx (node->left->code_label),
3117 /* Neither node is bounded. First distinguish the two sides;
3118 then emit the code for one side at a time. */
3120 tree test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
3122 /* See if the value is on the right. */
3123 emit_cmp_and_jump_insns (index,
3126 expand_expr (node->high, NULL_RTX,
3129 GT, NULL_RTX, mode, unsignedp,
3130 label_rtx (test_label));
3132 /* Value must be on the left.
3133 Handle the left-hand subtree. */
3134 emit_case_nodes (index, node->left, default_label, index_type);
3135 /* If left-hand subtree does nothing,
3137 emit_jump (default_label);
3139 /* Code branches here for the right-hand subtree. */
3140 expand_label (test_label);
3141 emit_case_nodes (index, node->right, default_label, index_type);
3145 else if (node->right != 0 && node->left == 0)
3147 /* Here we have a right child but no left so we issue conditional
3148 branch to default and process the right child.
3150 Omit the conditional branch to default if we it avoid only one
3151 right child; it costs too much space to save so little time. */
3153 if (node->right->right || node->right->left
3154 || !tree_int_cst_equal (node->right->low, node->right->high))
3156 if (!node_has_low_bound (node, index_type))
3158 emit_cmp_and_jump_insns (index,
3161 expand_expr (node->high, NULL_RTX,
3164 LT, NULL_RTX, mode, unsignedp,
3168 emit_case_nodes (index, node->right, default_label, index_type);
3171 /* We cannot process node->right normally
3172 since we haven't ruled out the numbers less than
3173 this node's value. So handle node->right explicitly. */
3174 do_jump_if_equal (index,
3177 expand_expr (node->right->low, NULL_RTX,
3180 label_rtx (node->right->code_label), unsignedp);
3183 else if (node->right == 0 && node->left != 0)
3185 /* Just one subtree, on the left. */
3186 if (node->left->left || node->left->right
3187 || !tree_int_cst_equal (node->left->low, node->left->high))
3189 if (!node_has_high_bound (node, index_type))
3191 emit_cmp_and_jump_insns (index,
3194 expand_expr (node->high, NULL_RTX,
3197 GT, NULL_RTX, mode, unsignedp,
3201 emit_case_nodes (index, node->left, default_label, index_type);
3204 /* We cannot process node->left normally
3205 since we haven't ruled out the numbers less than
3206 this node's value. So handle node->left explicitly. */
3207 do_jump_if_equal (index,
3210 expand_expr (node->left->low, NULL_RTX,
3213 label_rtx (node->left->code_label), unsignedp);
3218 /* Node is a range. These cases are very similar to those for a single
3219 value, except that we do not start by testing whether this node
3220 is the one to branch to. */
3222 if (node->right != 0 && node->left != 0)
3224 /* Node has subtrees on both sides.
3225 If the right-hand subtree is bounded,
3226 test for it first, since we can go straight there.
3227 Otherwise, we need to make a branch in the control structure,
3228 then handle the two subtrees. */
3229 tree test_label = 0;
3231 if (node_is_bounded (node->right, index_type))
3232 /* Right hand node is fully bounded so we can eliminate any
3233 testing and branch directly to the target code. */
3234 emit_cmp_and_jump_insns (index,
3237 expand_expr (node->high, NULL_RTX,
3240 GT, NULL_RTX, mode, unsignedp,
3241 label_rtx (node->right->code_label));
3244 /* Right hand node requires testing.
3245 Branch to a label where we will handle it later. */
3247 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
3248 emit_cmp_and_jump_insns (index,
3251 expand_expr (node->high, NULL_RTX,
3254 GT, NULL_RTX, mode, unsignedp,
3255 label_rtx (test_label));
3258 /* Value belongs to this node or to the left-hand subtree. */
3260 emit_cmp_and_jump_insns (index,
3263 expand_expr (node->low, NULL_RTX,
3266 GE, NULL_RTX, mode, unsignedp,
3267 label_rtx (node->code_label));
3269 /* Handle the left-hand subtree. */
3270 emit_case_nodes (index, node->left, default_label, index_type);
3272 /* If right node had to be handled later, do that now. */
3276 /* If the left-hand subtree fell through,
3277 don't let it fall into the right-hand subtree. */
3278 emit_jump (default_label);
3280 expand_label (test_label);
3281 emit_case_nodes (index, node->right, default_label, index_type);
3285 else if (node->right != 0 && node->left == 0)
3287 /* Deal with values to the left of this node,
3288 if they are possible. */
3289 if (!node_has_low_bound (node, index_type))
3291 emit_cmp_and_jump_insns (index,
3294 expand_expr (node->low, NULL_RTX,
3297 LT, NULL_RTX, mode, unsignedp,
3301 /* Value belongs to this node or to the right-hand subtree. */
3303 emit_cmp_and_jump_insns (index,
3306 expand_expr (node->high, NULL_RTX,
3309 LE, NULL_RTX, mode, unsignedp,
3310 label_rtx (node->code_label));
3312 emit_case_nodes (index, node->right, default_label, index_type);
3315 else if (node->right == 0 && node->left != 0)
3317 /* Deal with values to the right of this node,
3318 if they are possible. */
3319 if (!node_has_high_bound (node, index_type))
3321 emit_cmp_and_jump_insns (index,
3324 expand_expr (node->high, NULL_RTX,
3327 GT, NULL_RTX, mode, unsignedp,
3331 /* Value belongs to this node or to the left-hand subtree. */
3333 emit_cmp_and_jump_insns (index,
3336 expand_expr (node->low, NULL_RTX,
3339 GE, NULL_RTX, mode, unsignedp,
3340 label_rtx (node->code_label));
3342 emit_case_nodes (index, node->left, default_label, index_type);
3347 /* Node has no children so we check low and high bounds to remove
3348 redundant tests. Only one of the bounds can exist,
3349 since otherwise this node is bounded--a case tested already. */
3350 int high_bound = node_has_high_bound (node, index_type);
3351 int low_bound = node_has_low_bound (node, index_type);
3353 if (!high_bound && low_bound)
3355 emit_cmp_and_jump_insns (index,
3358 expand_expr (node->high, NULL_RTX,
3361 GT, NULL_RTX, mode, unsignedp,
3365 else if (!low_bound && high_bound)
3367 emit_cmp_and_jump_insns (index,
3370 expand_expr (node->low, NULL_RTX,
3373 LT, NULL_RTX, mode, unsignedp,
3376 else if (!low_bound && !high_bound)
3378 /* Widen LOW and HIGH to the same width as INDEX. */
3379 tree type = lang_hooks.types.type_for_mode (mode, unsignedp);
3380 tree low = build1 (CONVERT_EXPR, type, node->low);
3381 tree high = build1 (CONVERT_EXPR, type, node->high);
3382 rtx low_rtx, new_index, new_bound;
3384 /* Instead of doing two branches, emit one unsigned branch for
3385 (index-low) > (high-low). */
3386 low_rtx = expand_expr (low, NULL_RTX, mode, 0);
3387 new_index = expand_simple_binop (mode, MINUS, index, low_rtx,
3388 NULL_RTX, unsignedp,
3390 new_bound = expand_expr (fold (build2 (MINUS_EXPR, type,
3394 emit_cmp_and_jump_insns (new_index, new_bound, GT, NULL_RTX,
3395 mode, 1, default_label);
3398 emit_jump (label_rtx (node->code_label));