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, tree, tree);
128 /* Return the rtx-label that corresponds to a LABEL_DECL,
129 creating it if necessary. */
132 label_rtx (tree label)
134 gcc_assert (TREE_CODE (label) == LABEL_DECL);
136 if (!DECL_RTL_SET_P (label))
138 rtx r = gen_label_rtx ();
139 SET_DECL_RTL (label, r);
140 if (FORCED_LABEL (label) || DECL_NONLOCAL (label))
141 LABEL_PRESERVE_P (r) = 1;
144 return DECL_RTL (label);
147 /* As above, but also put it on the forced-reference list of the
148 function that contains it. */
150 force_label_rtx (tree label)
152 rtx ref = label_rtx (label);
153 tree function = decl_function_context (label);
156 gcc_assert (function);
158 if (function != current_function_decl)
159 p = find_function_data (function);
163 p->expr->x_forced_labels = gen_rtx_EXPR_LIST (VOIDmode, ref,
164 p->expr->x_forced_labels);
168 /* Add an unconditional jump to LABEL as the next sequential instruction. */
171 emit_jump (rtx label)
173 do_pending_stack_adjust ();
174 emit_jump_insn (gen_jump (label));
178 /* Emit code to jump to the address
179 specified by the pointer expression EXP. */
182 expand_computed_goto (tree exp)
184 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
186 x = convert_memory_address (Pmode, x);
188 do_pending_stack_adjust ();
189 emit_indirect_jump (x);
192 /* Handle goto statements and the labels that they can go to. */
194 /* Specify the location in the RTL code of a label LABEL,
195 which is a LABEL_DECL tree node.
197 This is used for the kind of label that the user can jump to with a
198 goto statement, and for alternatives of a switch or case statement.
199 RTL labels generated for loops and conditionals don't go through here;
200 they are generated directly at the RTL level, by other functions below.
202 Note that this has nothing to do with defining label *names*.
203 Languages vary in how they do that and what that even means. */
206 expand_label (tree label)
208 rtx label_r = label_rtx (label);
210 do_pending_stack_adjust ();
211 emit_label (label_r);
212 if (DECL_NAME (label))
213 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
215 if (DECL_NONLOCAL (label))
217 expand_nl_goto_receiver ();
218 nonlocal_goto_handler_labels
219 = gen_rtx_EXPR_LIST (VOIDmode, label_r,
220 nonlocal_goto_handler_labels);
223 if (FORCED_LABEL (label))
224 forced_labels = gen_rtx_EXPR_LIST (VOIDmode, label_r, forced_labels);
226 if (DECL_NONLOCAL (label) || FORCED_LABEL (label))
227 maybe_set_first_label_num (label_r);
230 /* Generate RTL code for a `goto' statement with target label LABEL.
231 LABEL should be a LABEL_DECL tree node that was or will later be
232 defined with `expand_label'. */
235 expand_goto (tree label)
237 #ifdef ENABLE_CHECKING
238 /* Check for a nonlocal goto to a containing function. Should have
239 gotten translated to __builtin_nonlocal_goto. */
240 tree context = decl_function_context (label);
241 gcc_assert (!context || context == current_function_decl);
244 emit_jump (label_rtx (label));
247 /* Return the number of times character C occurs in string S. */
249 n_occurrences (int c, const char *s)
257 /* Generate RTL for an asm statement (explicit assembler code).
258 STRING is a STRING_CST node containing the assembler code text,
259 or an ADDR_EXPR containing a STRING_CST. VOL nonzero means the
260 insn is volatile; don't optimize it. */
263 expand_asm (tree string, int vol)
267 if (TREE_CODE (string) == ADDR_EXPR)
268 string = TREE_OPERAND (string, 0);
270 body = gen_rtx_ASM_INPUT (VOIDmode, TREE_STRING_POINTER (string));
272 MEM_VOLATILE_P (body) = vol;
277 /* Parse the output constraint pointed to by *CONSTRAINT_P. It is the
278 OPERAND_NUMth output operand, indexed from zero. There are NINPUTS
279 inputs and NOUTPUTS outputs to this extended-asm. Upon return,
280 *ALLOWS_MEM will be TRUE iff the constraint allows the use of a
281 memory operand. Similarly, *ALLOWS_REG will be TRUE iff the
282 constraint allows the use of a register operand. And, *IS_INOUT
283 will be true if the operand is read-write, i.e., if it is used as
284 an input as well as an output. If *CONSTRAINT_P is not in
285 canonical form, it will be made canonical. (Note that `+' will be
286 replaced with `=' as part of this process.)
288 Returns TRUE if all went well; FALSE if an error occurred. */
291 parse_output_constraint (const char **constraint_p, int operand_num,
292 int ninputs, int noutputs, bool *allows_mem,
293 bool *allows_reg, bool *is_inout)
295 const char *constraint = *constraint_p;
298 /* Assume the constraint doesn't allow the use of either a register
303 /* Allow the `=' or `+' to not be at the beginning of the string,
304 since it wasn't explicitly documented that way, and there is a
305 large body of code that puts it last. Swap the character to
306 the front, so as not to uglify any place else. */
307 p = strchr (constraint, '=');
309 p = strchr (constraint, '+');
311 /* If the string doesn't contain an `=', issue an error
315 error ("output operand constraint lacks %<=%>");
319 /* If the constraint begins with `+', then the operand is both read
320 from and written to. */
321 *is_inout = (*p == '+');
323 /* Canonicalize the output constraint so that it begins with `='. */
324 if (p != constraint || is_inout)
327 size_t c_len = strlen (constraint);
330 warning ("output constraint %qc for operand %d "
331 "is not at the beginning",
334 /* Make a copy of the constraint. */
335 buf = alloca (c_len + 1);
336 strcpy (buf, constraint);
337 /* Swap the first character and the `=' or `+'. */
338 buf[p - constraint] = buf[0];
339 /* Make sure the first character is an `='. (Until we do this,
340 it might be a `+'.) */
342 /* Replace the constraint with the canonicalized string. */
343 *constraint_p = ggc_alloc_string (buf, c_len);
344 constraint = *constraint_p;
347 /* Loop through the constraint string. */
348 for (p = constraint + 1; *p; p += CONSTRAINT_LEN (*p, p))
353 error ("operand constraint contains incorrectly positioned "
358 if (operand_num + 1 == ninputs + noutputs)
360 error ("%<%%%> constraint used with last operand");
365 case 'V': case 'm': case 'o':
369 case '?': case '!': case '*': case '&': case '#':
370 case 'E': case 'F': case 'G': case 'H':
371 case 's': case 'i': case 'n':
372 case 'I': case 'J': case 'K': case 'L': case 'M':
373 case 'N': case 'O': case 'P': case ',':
376 case '0': case '1': case '2': case '3': case '4':
377 case '5': case '6': case '7': case '8': case '9':
379 error ("matching constraint not valid in output operand");
383 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
384 excepting those that expand_call created. So match memory
401 if (REG_CLASS_FROM_CONSTRAINT (*p, p) != NO_REGS)
403 #ifdef EXTRA_CONSTRAINT_STR
404 else if (EXTRA_ADDRESS_CONSTRAINT (*p, p))
406 else if (EXTRA_MEMORY_CONSTRAINT (*p, p))
410 /* Otherwise we can't assume anything about the nature of
411 the constraint except that it isn't purely registers.
412 Treat it like "g" and hope for the best. */
423 /* Similar, but for input constraints. */
426 parse_input_constraint (const char **constraint_p, int input_num,
427 int ninputs, int noutputs, int ninout,
428 const char * const * constraints,
429 bool *allows_mem, bool *allows_reg)
431 const char *constraint = *constraint_p;
432 const char *orig_constraint = constraint;
433 size_t c_len = strlen (constraint);
435 bool saw_match = false;
437 /* Assume the constraint doesn't allow the use of either
438 a register or memory. */
442 /* Make sure constraint has neither `=', `+', nor '&'. */
444 for (j = 0; j < c_len; j += CONSTRAINT_LEN (constraint[j], constraint+j))
445 switch (constraint[j])
447 case '+': case '=': case '&':
448 if (constraint == orig_constraint)
450 error ("input operand constraint contains %qc", constraint[j]);
456 if (constraint == orig_constraint
457 && input_num + 1 == ninputs - ninout)
459 error ("%<%%%> constraint used with last operand");
464 case 'V': case 'm': case 'o':
469 case '?': case '!': case '*': case '#':
470 case 'E': case 'F': case 'G': case 'H':
471 case 's': case 'i': case 'n':
472 case 'I': case 'J': case 'K': case 'L': case 'M':
473 case 'N': case 'O': case 'P': case ',':
476 /* Whether or not a numeric constraint allows a register is
477 decided by the matching constraint, and so there is no need
478 to do anything special with them. We must handle them in
479 the default case, so that we don't unnecessarily force
480 operands to memory. */
481 case '0': case '1': case '2': case '3': case '4':
482 case '5': case '6': case '7': case '8': case '9':
489 match = strtoul (constraint + j, &end, 10);
490 if (match >= (unsigned long) noutputs)
492 error ("matching constraint references invalid operand number");
496 /* Try and find the real constraint for this dup. Only do this
497 if the matching constraint is the only alternative. */
499 && (j == 0 || (j == 1 && constraint[0] == '%')))
501 constraint = constraints[match];
502 *constraint_p = constraint;
503 c_len = strlen (constraint);
505 /* ??? At the end of the loop, we will skip the first part of
506 the matched constraint. This assumes not only that the
507 other constraint is an output constraint, but also that
508 the '=' or '+' come first. */
512 j = end - constraint;
513 /* Anticipate increment at end of loop. */
528 if (! ISALPHA (constraint[j]))
530 error ("invalid punctuation %qc in constraint", constraint[j]);
533 if (REG_CLASS_FROM_CONSTRAINT (constraint[j], constraint + j)
536 #ifdef EXTRA_CONSTRAINT_STR
537 else if (EXTRA_ADDRESS_CONSTRAINT (constraint[j], constraint + j))
539 else if (EXTRA_MEMORY_CONSTRAINT (constraint[j], constraint + j))
543 /* Otherwise we can't assume anything about the nature of
544 the constraint except that it isn't purely registers.
545 Treat it like "g" and hope for the best. */
553 if (saw_match && !*allows_reg)
554 warning ("matching constraint does not allow a register");
559 /* INPUT is one of the input operands from EXPR, an ASM_EXPR. Returns true
560 if it is an operand which must be passed in memory (i.e. an "m"
561 constraint), false otherwise. */
564 asm_op_is_mem_input (tree input, tree expr)
566 const char *constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (input)));
567 tree outputs = ASM_OUTPUTS (expr);
568 int noutputs = list_length (outputs);
569 const char **constraints
570 = (const char **) alloca ((noutputs) * sizeof (const char *));
572 bool allows_mem, allows_reg;
575 /* Collect output constraints. */
576 for (t = outputs; t ; t = TREE_CHAIN (t), i++)
577 constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
579 /* We pass 0 for input_num, ninputs and ninout; they are only used for
580 error checking which will be done at expand time. */
581 parse_input_constraint (&constraint, 0, 0, noutputs, 0, constraints,
582 &allows_mem, &allows_reg);
583 return (!allows_reg && allows_mem);
586 /* Check for overlap between registers marked in CLOBBERED_REGS and
587 anything inappropriate in DECL. Emit error and return TRUE for error,
591 decl_conflicts_with_clobbers_p (tree decl, const HARD_REG_SET clobbered_regs)
593 /* Conflicts between asm-declared register variables and the clobber
594 list are not allowed. */
595 if ((TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == PARM_DECL)
596 && DECL_REGISTER (decl)
597 && REG_P (DECL_RTL (decl))
598 && REGNO (DECL_RTL (decl)) < FIRST_PSEUDO_REGISTER)
600 rtx reg = DECL_RTL (decl);
603 for (regno = REGNO (reg);
605 + hard_regno_nregs[REGNO (reg)][GET_MODE (reg)]);
607 if (TEST_HARD_REG_BIT (clobbered_regs, regno))
609 error ("asm-specifier for variable %qs conflicts with "
611 IDENTIFIER_POINTER (DECL_NAME (decl)));
613 /* Reset registerness to stop multiple errors emitted for a
615 DECL_REGISTER (decl) = 0;
622 /* Generate RTL for an asm statement with arguments.
623 STRING is the instruction template.
624 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
625 Each output or input has an expression in the TREE_VALUE and
626 and a tree list in TREE_PURPOSE which in turn contains a constraint
627 name in TREE_VALUE (or NULL_TREE) and a constraint string
629 CLOBBERS is a list of STRING_CST nodes each naming a hard register
630 that is clobbered by this insn.
632 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
633 Some elements of OUTPUTS may be replaced with trees representing temporary
634 values. The caller should copy those temporary values to the originally
637 VOL nonzero means the insn is volatile; don't optimize it. */
640 expand_asm_operands (tree string, tree outputs, tree inputs,
641 tree clobbers, int vol, location_t locus)
643 rtvec argvec, constraintvec;
645 int ninputs = list_length (inputs);
646 int noutputs = list_length (outputs);
649 HARD_REG_SET clobbered_regs;
650 int clobber_conflict_found = 0;
654 /* Vector of RTX's of evaluated output operands. */
655 rtx *output_rtx = alloca (noutputs * sizeof (rtx));
656 int *inout_opnum = alloca (noutputs * sizeof (int));
657 rtx *real_output_rtx = alloca (noutputs * sizeof (rtx));
658 enum machine_mode *inout_mode
659 = alloca (noutputs * sizeof (enum machine_mode));
660 const char **constraints
661 = alloca ((noutputs + ninputs) * sizeof (const char *));
662 int old_generating_concat_p = generating_concat_p;
664 /* An ASM with no outputs needs to be treated as volatile, for now. */
668 if (! check_operand_nalternatives (outputs, inputs))
671 string = resolve_asm_operand_names (string, outputs, inputs);
673 /* Collect constraints. */
675 for (t = outputs; t ; t = TREE_CHAIN (t), i++)
676 constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
677 for (t = inputs; t ; t = TREE_CHAIN (t), i++)
678 constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
680 /* Sometimes we wish to automatically clobber registers across an asm.
681 Case in point is when the i386 backend moved from cc0 to a hard reg --
682 maintaining source-level compatibility means automatically clobbering
683 the flags register. */
684 clobbers = targetm.md_asm_clobbers (clobbers);
686 /* Count the number of meaningful clobbered registers, ignoring what
687 we would ignore later. */
689 CLEAR_HARD_REG_SET (clobbered_regs);
690 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
692 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
694 i = decode_reg_name (regname);
695 if (i >= 0 || i == -4)
698 error ("unknown register name %qs in %<asm%>", regname);
700 /* Mark clobbered registers. */
703 /* Clobbering the PIC register is an error */
704 if (i == (int) PIC_OFFSET_TABLE_REGNUM)
706 error ("PIC register %qs clobbered in %<asm%>", regname);
710 SET_HARD_REG_BIT (clobbered_regs, i);
714 /* First pass over inputs and outputs checks validity and sets
715 mark_addressable if needed. */
718 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
720 tree val = TREE_VALUE (tail);
721 tree type = TREE_TYPE (val);
722 const char *constraint;
727 /* If there's an erroneous arg, emit no insn. */
728 if (type == error_mark_node)
731 /* Try to parse the output constraint. If that fails, there's
732 no point in going further. */
733 constraint = constraints[i];
734 if (!parse_output_constraint (&constraint, i, ninputs, noutputs,
735 &allows_mem, &allows_reg, &is_inout))
742 && REG_P (DECL_RTL (val))
743 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type))))
744 lang_hooks.mark_addressable (val);
751 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
753 error ("more than %d operands in %<asm%>", MAX_RECOG_OPERANDS);
757 for (i = 0, tail = inputs; tail; i++, tail = TREE_CHAIN (tail))
759 bool allows_reg, allows_mem;
760 const char *constraint;
762 /* If there's an erroneous arg, emit no insn, because the ASM_INPUT
763 would get VOIDmode and that could cause a crash in reload. */
764 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
767 constraint = constraints[i + noutputs];
768 if (! parse_input_constraint (&constraint, i, ninputs, noutputs, ninout,
769 constraints, &allows_mem, &allows_reg))
772 if (! allows_reg && allows_mem)
773 lang_hooks.mark_addressable (TREE_VALUE (tail));
776 /* Second pass evaluates arguments. */
779 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
781 tree val = TREE_VALUE (tail);
782 tree type = TREE_TYPE (val);
789 ok = parse_output_constraint (&constraints[i], i, ninputs,
790 noutputs, &allows_mem, &allows_reg,
794 /* If an output operand is not a decl or indirect ref and our constraint
795 allows a register, make a temporary to act as an intermediate.
796 Make the asm insn write into that, then our caller will copy it to
797 the real output operand. Likewise for promoted variables. */
799 generating_concat_p = 0;
801 real_output_rtx[i] = NULL_RTX;
802 if ((TREE_CODE (val) == INDIRECT_REF
805 && (allows_mem || REG_P (DECL_RTL (val)))
806 && ! (REG_P (DECL_RTL (val))
807 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
811 op = expand_expr (val, NULL_RTX, VOIDmode, EXPAND_WRITE);
813 op = validize_mem (op);
815 if (! allows_reg && !MEM_P (op))
816 error ("output number %d not directly addressable", i);
817 if ((! allows_mem && MEM_P (op))
818 || GET_CODE (op) == CONCAT)
820 real_output_rtx[i] = op;
821 op = gen_reg_rtx (GET_MODE (op));
823 emit_move_insn (op, real_output_rtx[i]);
828 op = assign_temp (type, 0, 0, 1);
829 op = validize_mem (op);
830 TREE_VALUE (tail) = make_tree (type, op);
834 generating_concat_p = old_generating_concat_p;
838 inout_mode[ninout] = TYPE_MODE (type);
839 inout_opnum[ninout++] = i;
842 if (decl_conflicts_with_clobbers_p (val, clobbered_regs))
843 clobber_conflict_found = 1;
846 /* Make vectors for the expression-rtx, constraint strings,
847 and named operands. */
849 argvec = rtvec_alloc (ninputs);
850 constraintvec = rtvec_alloc (ninputs);
852 body = gen_rtx_ASM_OPERANDS ((noutputs == 0 ? VOIDmode
853 : GET_MODE (output_rtx[0])),
854 TREE_STRING_POINTER (string),
855 empty_string, 0, argvec, constraintvec,
858 MEM_VOLATILE_P (body) = vol;
860 /* Eval the inputs and put them into ARGVEC.
861 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
863 for (i = 0, tail = inputs; tail; tail = TREE_CHAIN (tail), ++i)
865 bool allows_reg, allows_mem;
866 const char *constraint;
871 constraint = constraints[i + noutputs];
872 ok = parse_input_constraint (&constraint, i, ninputs, noutputs, ninout,
873 constraints, &allows_mem, &allows_reg);
876 generating_concat_p = 0;
878 val = TREE_VALUE (tail);
879 type = TREE_TYPE (val);
880 op = expand_expr (val, NULL_RTX, VOIDmode,
881 (allows_mem && !allows_reg
882 ? EXPAND_MEMORY : EXPAND_NORMAL));
884 /* Never pass a CONCAT to an ASM. */
885 if (GET_CODE (op) == CONCAT)
886 op = force_reg (GET_MODE (op), op);
888 op = validize_mem (op);
890 if (asm_operand_ok (op, constraint) <= 0)
893 op = force_reg (TYPE_MODE (type), op);
894 else if (!allows_mem)
895 warning ("asm operand %d probably doesn%'t match constraints",
899 /* We won't recognize either volatile memory or memory
900 with a queued address as available a memory_operand
901 at this point. Ignore it: clearly this *is* a memory. */
905 warning ("use of memory input without lvalue in "
906 "asm operand %d is deprecated", i + noutputs);
910 rtx mem = force_const_mem (TYPE_MODE (type), op);
912 op = validize_mem (mem);
914 op = force_reg (TYPE_MODE (type), op);
917 || GET_CODE (op) == SUBREG
918 || GET_CODE (op) == CONCAT)
920 tree qual_type = build_qualified_type (type,
923 rtx memloc = assign_temp (qual_type, 1, 1, 1);
924 memloc = validize_mem (memloc);
925 emit_move_insn (memloc, op);
931 generating_concat_p = old_generating_concat_p;
932 ASM_OPERANDS_INPUT (body, i) = op;
934 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, i)
935 = gen_rtx_ASM_INPUT (TYPE_MODE (type), constraints[i + noutputs]);
937 if (decl_conflicts_with_clobbers_p (val, clobbered_regs))
938 clobber_conflict_found = 1;
941 /* Protect all the operands from the queue now that they have all been
944 generating_concat_p = 0;
946 /* For in-out operands, copy output rtx to input rtx. */
947 for (i = 0; i < ninout; i++)
949 int j = inout_opnum[i];
952 ASM_OPERANDS_INPUT (body, ninputs - ninout + i)
955 sprintf (buffer, "%d", j);
956 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, ninputs - ninout + i)
957 = gen_rtx_ASM_INPUT (inout_mode[i], ggc_strdup (buffer));
960 generating_concat_p = old_generating_concat_p;
962 /* Now, for each output, construct an rtx
963 (set OUTPUT (asm_operands INSN OUTPUTCONSTRAINT OUTPUTNUMBER
964 ARGVEC CONSTRAINTS OPNAMES))
965 If there is more than one, put them inside a PARALLEL. */
967 if (noutputs == 1 && nclobbers == 0)
969 ASM_OPERANDS_OUTPUT_CONSTRAINT (body) = constraints[0];
970 emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
973 else if (noutputs == 0 && nclobbers == 0)
975 /* No output operands: put in a raw ASM_OPERANDS rtx. */
987 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
989 /* For each output operand, store a SET. */
990 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
993 = gen_rtx_SET (VOIDmode,
996 (GET_MODE (output_rtx[i]),
997 TREE_STRING_POINTER (string),
998 constraints[i], i, argvec, constraintvec,
1001 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1004 /* If there are no outputs (but there are some clobbers)
1005 store the bare ASM_OPERANDS into the PARALLEL. */
1008 XVECEXP (body, 0, i++) = obody;
1010 /* Store (clobber REG) for each clobbered register specified. */
1012 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1014 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1015 int j = decode_reg_name (regname);
1020 if (j == -3) /* `cc', which is not a register */
1023 if (j == -4) /* `memory', don't cache memory across asm */
1025 XVECEXP (body, 0, i++)
1026 = gen_rtx_CLOBBER (VOIDmode,
1029 gen_rtx_SCRATCH (VOIDmode)));
1033 /* Ignore unknown register, error already signaled. */
1037 /* Use QImode since that's guaranteed to clobber just one reg. */
1038 clobbered_reg = gen_rtx_REG (QImode, j);
1040 /* Do sanity check for overlap between clobbers and respectively
1041 input and outputs that hasn't been handled. Such overlap
1042 should have been detected and reported above. */
1043 if (!clobber_conflict_found)
1047 /* We test the old body (obody) contents to avoid tripping
1048 over the under-construction body. */
1049 for (opno = 0; opno < noutputs; opno++)
1050 if (reg_overlap_mentioned_p (clobbered_reg, output_rtx[opno]))
1051 internal_error ("asm clobber conflict with output operand");
1053 for (opno = 0; opno < ninputs - ninout; opno++)
1054 if (reg_overlap_mentioned_p (clobbered_reg,
1055 ASM_OPERANDS_INPUT (obody, opno)))
1056 internal_error ("asm clobber conflict with input operand");
1059 XVECEXP (body, 0, i++)
1060 = gen_rtx_CLOBBER (VOIDmode, clobbered_reg);
1066 /* For any outputs that needed reloading into registers, spill them
1067 back to where they belong. */
1068 for (i = 0; i < noutputs; ++i)
1069 if (real_output_rtx[i])
1070 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1076 expand_asm_expr (tree exp)
1082 if (ASM_INPUT_P (exp))
1084 expand_asm (ASM_STRING (exp), ASM_VOLATILE_P (exp));
1088 outputs = ASM_OUTPUTS (exp);
1089 noutputs = list_length (outputs);
1090 /* o[I] is the place that output number I should be written. */
1091 o = (tree *) alloca (noutputs * sizeof (tree));
1093 /* Record the contents of OUTPUTS before it is modified. */
1094 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1095 o[i] = TREE_VALUE (tail);
1097 /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
1098 OUTPUTS some trees for where the values were actually stored. */
1099 expand_asm_operands (ASM_STRING (exp), outputs, ASM_INPUTS (exp),
1100 ASM_CLOBBERS (exp), ASM_VOLATILE_P (exp),
1103 /* Copy all the intermediate outputs into the specified outputs. */
1104 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1106 if (o[i] != TREE_VALUE (tail))
1108 expand_assignment (o[i], TREE_VALUE (tail), 0);
1111 /* Restore the original value so that it's correct the next
1112 time we expand this function. */
1113 TREE_VALUE (tail) = o[i];
1118 /* A subroutine of expand_asm_operands. Check that all operands have
1119 the same number of alternatives. Return true if so. */
1122 check_operand_nalternatives (tree outputs, tree inputs)
1124 if (outputs || inputs)
1126 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1128 = n_occurrences (',', TREE_STRING_POINTER (TREE_VALUE (tmp)));
1131 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1133 error ("too many alternatives in %<asm%>");
1140 const char *constraint
1141 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tmp)));
1143 if (n_occurrences (',', constraint) != nalternatives)
1145 error ("operand constraints for %<asm%> differ "
1146 "in number of alternatives");
1150 if (TREE_CHAIN (tmp))
1151 tmp = TREE_CHAIN (tmp);
1153 tmp = next, next = 0;
1160 /* A subroutine of expand_asm_operands. Check that all operand names
1161 are unique. Return true if so. We rely on the fact that these names
1162 are identifiers, and so have been canonicalized by get_identifier,
1163 so all we need are pointer comparisons. */
1166 check_unique_operand_names (tree outputs, tree inputs)
1170 for (i = outputs; i ; i = TREE_CHAIN (i))
1172 tree i_name = TREE_PURPOSE (TREE_PURPOSE (i));
1176 for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j))
1177 if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
1181 for (i = inputs; i ; i = TREE_CHAIN (i))
1183 tree i_name = TREE_PURPOSE (TREE_PURPOSE (i));
1187 for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j))
1188 if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
1190 for (j = outputs; j ; j = TREE_CHAIN (j))
1191 if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
1198 error ("duplicate asm operand name %qs",
1199 TREE_STRING_POINTER (TREE_PURPOSE (TREE_PURPOSE (i))));
1203 /* A subroutine of expand_asm_operands. Resolve the names of the operands
1204 in *POUTPUTS and *PINPUTS to numbers, and replace the name expansions in
1205 STRING and in the constraints to those numbers. */
1208 resolve_asm_operand_names (tree string, tree outputs, tree inputs)
1215 check_unique_operand_names (outputs, inputs);
1217 /* Substitute [<name>] in input constraint strings. There should be no
1218 named operands in output constraints. */
1219 for (t = inputs; t ; t = TREE_CHAIN (t))
1221 c = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
1222 if (strchr (c, '[') != NULL)
1224 p = buffer = xstrdup (c);
1225 while ((p = strchr (p, '[')) != NULL)
1226 p = resolve_operand_name_1 (p, outputs, inputs);
1227 TREE_VALUE (TREE_PURPOSE (t))
1228 = build_string (strlen (buffer), buffer);
1233 /* Now check for any needed substitutions in the template. */
1234 c = TREE_STRING_POINTER (string);
1235 while ((c = strchr (c, '%')) != NULL)
1239 else if (ISALPHA (c[1]) && c[2] == '[')
1250 /* OK, we need to make a copy so we can perform the substitutions.
1251 Assume that we will not need extra space--we get to remove '['
1252 and ']', which means we cannot have a problem until we have more
1253 than 999 operands. */
1254 buffer = xstrdup (TREE_STRING_POINTER (string));
1255 p = buffer + (c - TREE_STRING_POINTER (string));
1257 while ((p = strchr (p, '%')) != NULL)
1261 else if (ISALPHA (p[1]) && p[2] == '[')
1269 p = resolve_operand_name_1 (p, outputs, inputs);
1272 string = build_string (strlen (buffer), buffer);
1279 /* A subroutine of resolve_operand_names. P points to the '[' for a
1280 potential named operand of the form [<name>]. In place, replace
1281 the name and brackets with a number. Return a pointer to the
1282 balance of the string after substitution. */
1285 resolve_operand_name_1 (char *p, tree outputs, tree inputs)
1292 /* Collect the operand name. */
1293 q = strchr (p, ']');
1296 error ("missing close brace for named operand");
1297 return strchr (p, '\0');
1301 /* Resolve the name to a number. */
1302 for (op = 0, t = outputs; t ; t = TREE_CHAIN (t), op++)
1304 tree name = TREE_PURPOSE (TREE_PURPOSE (t));
1307 const char *c = TREE_STRING_POINTER (name);
1308 if (strncmp (c, p + 1, len) == 0 && c[len] == '\0')
1312 for (t = inputs; t ; t = TREE_CHAIN (t), op++)
1314 tree name = TREE_PURPOSE (TREE_PURPOSE (t));
1317 const char *c = TREE_STRING_POINTER (name);
1318 if (strncmp (c, p + 1, len) == 0 && c[len] == '\0')
1324 error ("undefined named operand %qs", p + 1);
1328 /* Replace the name with the number. Unfortunately, not all libraries
1329 get the return value of sprintf correct, so search for the end of the
1330 generated string by hand. */
1331 sprintf (p, "%d", op);
1332 p = strchr (p, '\0');
1334 /* Verify the no extra buffer space assumption. */
1335 gcc_assert (p <= q);
1337 /* Shift the rest of the buffer down to fill the gap. */
1338 memmove (p, q + 1, strlen (q + 1) + 1);
1343 /* Generate RTL to evaluate the expression EXP. */
1346 expand_expr_stmt (tree exp)
1351 value = expand_expr (exp, const0_rtx, VOIDmode, 0);
1352 type = TREE_TYPE (exp);
1354 /* If all we do is reference a volatile value in memory,
1355 copy it to a register to be sure it is actually touched. */
1356 if (value && MEM_P (value) && TREE_THIS_VOLATILE (exp))
1358 if (TYPE_MODE (type) == VOIDmode)
1360 else if (TYPE_MODE (type) != BLKmode)
1361 value = copy_to_reg (value);
1364 rtx lab = gen_label_rtx ();
1366 /* Compare the value with itself to reference it. */
1367 emit_cmp_and_jump_insns (value, value, EQ,
1368 expand_expr (TYPE_SIZE (type),
1369 NULL_RTX, VOIDmode, 0),
1375 /* Free any temporaries used to evaluate this expression. */
1379 /* Warn if EXP contains any computations whose results are not used.
1380 Return 1 if a warning is printed; 0 otherwise. LOCUS is the
1381 (potential) location of the expression. */
1384 warn_if_unused_value (tree exp, location_t locus)
1387 if (TREE_USED (exp))
1390 /* Don't warn about void constructs. This includes casting to void,
1391 void function calls, and statement expressions with a final cast
1393 if (VOID_TYPE_P (TREE_TYPE (exp)))
1396 if (EXPR_HAS_LOCATION (exp))
1397 locus = EXPR_LOCATION (exp);
1399 switch (TREE_CODE (exp))
1401 case PREINCREMENT_EXPR:
1402 case POSTINCREMENT_EXPR:
1403 case PREDECREMENT_EXPR:
1404 case POSTDECREMENT_EXPR:
1409 case TRY_CATCH_EXPR:
1410 case WITH_CLEANUP_EXPR:
1415 /* For a binding, warn if no side effect within it. */
1416 exp = BIND_EXPR_BODY (exp);
1420 exp = TREE_OPERAND (exp, 0);
1423 case TRUTH_ORIF_EXPR:
1424 case TRUTH_ANDIF_EXPR:
1425 /* In && or ||, warn if 2nd operand has no side effect. */
1426 exp = TREE_OPERAND (exp, 1);
1430 if (TREE_NO_WARNING (exp))
1432 if (warn_if_unused_value (TREE_OPERAND (exp, 0), locus))
1434 /* Let people do `(foo (), 0)' without a warning. */
1435 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1437 exp = TREE_OPERAND (exp, 1);
1442 case NON_LVALUE_EXPR:
1443 /* Don't warn about conversions not explicit in the user's program. */
1444 if (TREE_NO_WARNING (exp))
1446 /* Assignment to a cast usually results in a cast of a modify.
1447 Don't complain about that. There can be an arbitrary number of
1448 casts before the modify, so we must loop until we find the first
1449 non-cast expression and then test to see if that is a modify. */
1451 tree tem = TREE_OPERAND (exp, 0);
1453 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1454 tem = TREE_OPERAND (tem, 0);
1456 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1457 || TREE_CODE (tem) == CALL_EXPR)
1463 /* Don't warn about automatic dereferencing of references, since
1464 the user cannot control it. */
1465 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1467 exp = TREE_OPERAND (exp, 0);
1473 /* Referencing a volatile value is a side effect, so don't warn. */
1474 if ((DECL_P (exp) || REFERENCE_CLASS_P (exp))
1475 && TREE_THIS_VOLATILE (exp))
1478 /* If this is an expression which has no operands, there is no value
1479 to be unused. There are no such language-independent codes,
1480 but front ends may define such. */
1481 if (EXPRESSION_CLASS_P (exp) && TREE_CODE_LENGTH (TREE_CODE (exp)) == 0)
1485 /* If this is an expression with side effects, don't warn. */
1486 if (TREE_SIDE_EFFECTS (exp))
1489 warning ("%Hvalue computed is not used", &locus);
1495 /* Generate RTL to return from the current function, with no value.
1496 (That is, we do not do anything about returning any value.) */
1499 expand_null_return (void)
1501 /* If this function was declared to return a value, but we
1502 didn't, clobber the return registers so that they are not
1503 propagated live to the rest of the function. */
1504 clobber_return_register ();
1506 expand_null_return_1 ();
1509 /* Generate RTL to return directly from the current function.
1510 (That is, we bypass any return value.) */
1513 expand_naked_return (void)
1517 clear_pending_stack_adjust ();
1518 do_pending_stack_adjust ();
1520 end_label = naked_return_label;
1522 end_label = naked_return_label = gen_label_rtx ();
1524 emit_jump (end_label);
1527 /* If the current function returns values in the most significant part
1528 of a register, shift return value VAL appropriately. The mode of
1529 the function's return type is known not to be BLKmode. */
1532 shift_return_value (rtx val)
1536 type = TREE_TYPE (DECL_RESULT (current_function_decl));
1537 if (targetm.calls.return_in_msb (type))
1540 HOST_WIDE_INT shift;
1542 target = DECL_RTL (DECL_RESULT (current_function_decl));
1543 shift = (GET_MODE_BITSIZE (GET_MODE (target))
1544 - BITS_PER_UNIT * int_size_in_bytes (type));
1546 val = expand_shift (LSHIFT_EXPR, GET_MODE (target),
1547 gen_lowpart (GET_MODE (target), val),
1548 build_int_cst (NULL_TREE, shift), target, 1);
1554 /* Generate RTL to return from the current function, with value VAL. */
1557 expand_value_return (rtx val)
1559 /* Copy the value to the return location
1560 unless it's already there. */
1562 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
1563 if (return_reg != val)
1565 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
1566 if (targetm.calls.promote_function_return (TREE_TYPE (current_function_decl)))
1568 int unsignedp = TYPE_UNSIGNED (type);
1569 enum machine_mode old_mode
1570 = DECL_MODE (DECL_RESULT (current_function_decl));
1571 enum machine_mode mode
1572 = promote_mode (type, old_mode, &unsignedp, 1);
1574 if (mode != old_mode)
1575 val = convert_modes (mode, old_mode, val, unsignedp);
1577 if (GET_CODE (return_reg) == PARALLEL)
1578 emit_group_load (return_reg, val, type, int_size_in_bytes (type));
1580 emit_move_insn (return_reg, val);
1583 expand_null_return_1 ();
1586 /* Output a return with no value. */
1589 expand_null_return_1 (void)
1593 clear_pending_stack_adjust ();
1594 do_pending_stack_adjust ();
1596 end_label = return_label;
1598 end_label = return_label = gen_label_rtx ();
1599 emit_jump (end_label);
1602 /* Generate RTL to evaluate the expression RETVAL and return it
1603 from the current function. */
1606 expand_return (tree retval)
1612 /* If function wants no value, give it none. */
1613 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
1615 expand_expr (retval, NULL_RTX, VOIDmode, 0);
1616 expand_null_return ();
1620 if (retval == error_mark_node)
1622 /* Treat this like a return of no value from a function that
1624 expand_null_return ();
1627 else if ((TREE_CODE (retval) == MODIFY_EXPR
1628 || TREE_CODE (retval) == INIT_EXPR)
1629 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
1630 retval_rhs = TREE_OPERAND (retval, 1);
1632 retval_rhs = retval;
1634 result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
1636 /* If we are returning the RESULT_DECL, then the value has already
1637 been stored into it, so we don't have to do anything special. */
1638 if (TREE_CODE (retval_rhs) == RESULT_DECL)
1639 expand_value_return (result_rtl);
1641 /* If the result is an aggregate that is being returned in one (or more)
1642 registers, load the registers here. The compiler currently can't handle
1643 copying a BLKmode value into registers. We could put this code in a
1644 more general area (for use by everyone instead of just function
1645 call/return), but until this feature is generally usable it is kept here
1646 (and in expand_call). */
1648 else if (retval_rhs != 0
1649 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
1650 && REG_P (result_rtl))
1653 unsigned HOST_WIDE_INT bitpos, xbitpos;
1654 unsigned HOST_WIDE_INT padding_correction = 0;
1655 unsigned HOST_WIDE_INT bytes
1656 = int_size_in_bytes (TREE_TYPE (retval_rhs));
1657 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
1658 unsigned int bitsize
1659 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), BITS_PER_WORD);
1660 rtx *result_pseudos = alloca (sizeof (rtx) * n_regs);
1661 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
1662 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
1663 enum machine_mode tmpmode, result_reg_mode;
1667 expand_null_return ();
1671 /* If the structure doesn't take up a whole number of words, see
1672 whether the register value should be padded on the left or on
1673 the right. Set PADDING_CORRECTION to the number of padding
1674 bits needed on the left side.
1676 In most ABIs, the structure will be returned at the least end of
1677 the register, which translates to right padding on little-endian
1678 targets and left padding on big-endian targets. The opposite
1679 holds if the structure is returned at the most significant
1680 end of the register. */
1681 if (bytes % UNITS_PER_WORD != 0
1682 && (targetm.calls.return_in_msb (TREE_TYPE (retval_rhs))
1684 : BYTES_BIG_ENDIAN))
1685 padding_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
1688 /* Copy the structure BITSIZE bits at a time. */
1689 for (bitpos = 0, xbitpos = padding_correction;
1690 bitpos < bytes * BITS_PER_UNIT;
1691 bitpos += bitsize, xbitpos += bitsize)
1693 /* We need a new destination pseudo each time xbitpos is
1694 on a word boundary and when xbitpos == padding_correction
1695 (the first time through). */
1696 if (xbitpos % BITS_PER_WORD == 0
1697 || xbitpos == padding_correction)
1699 /* Generate an appropriate register. */
1700 dst = gen_reg_rtx (word_mode);
1701 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
1703 /* Clear the destination before we move anything into it. */
1704 emit_move_insn (dst, CONST0_RTX (GET_MODE (dst)));
1707 /* We need a new source operand each time bitpos is on a word
1709 if (bitpos % BITS_PER_WORD == 0)
1710 src = operand_subword_force (result_val,
1711 bitpos / BITS_PER_WORD,
1714 /* Use bitpos for the source extraction (left justified) and
1715 xbitpos for the destination store (right justified). */
1716 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
1717 extract_bit_field (src, bitsize,
1718 bitpos % BITS_PER_WORD, 1,
1719 NULL_RTX, word_mode, word_mode));
1722 tmpmode = GET_MODE (result_rtl);
1723 if (tmpmode == BLKmode)
1725 /* Find the smallest integer mode large enough to hold the
1726 entire structure and use that mode instead of BLKmode
1727 on the USE insn for the return register. */
1728 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
1729 tmpmode != VOIDmode;
1730 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
1731 /* Have we found a large enough mode? */
1732 if (GET_MODE_SIZE (tmpmode) >= bytes)
1735 /* A suitable mode should have been found. */
1736 gcc_assert (tmpmode != VOIDmode);
1738 PUT_MODE (result_rtl, tmpmode);
1741 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
1742 result_reg_mode = word_mode;
1744 result_reg_mode = tmpmode;
1745 result_reg = gen_reg_rtx (result_reg_mode);
1747 for (i = 0; i < n_regs; i++)
1748 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
1751 if (tmpmode != result_reg_mode)
1752 result_reg = gen_lowpart (tmpmode, result_reg);
1754 expand_value_return (result_reg);
1756 else if (retval_rhs != 0
1757 && !VOID_TYPE_P (TREE_TYPE (retval_rhs))
1758 && (REG_P (result_rtl)
1759 || (GET_CODE (result_rtl) == PARALLEL)))
1761 /* Calculate the return value into a temporary (usually a pseudo
1763 tree ot = TREE_TYPE (DECL_RESULT (current_function_decl));
1764 tree nt = build_qualified_type (ot, TYPE_QUALS (ot) | TYPE_QUAL_CONST);
1766 val = assign_temp (nt, 0, 0, 1);
1767 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
1768 val = force_not_mem (val);
1769 /* Return the calculated value. */
1770 expand_value_return (shift_return_value (val));
1774 /* No hard reg used; calculate value into hard return reg. */
1775 expand_expr (retval, const0_rtx, VOIDmode, 0);
1776 expand_value_return (result_rtl);
1780 /* Given a pointer to a BLOCK node return nonzero if (and only if) the node
1781 in question represents the outermost pair of curly braces (i.e. the "body
1782 block") of a function or method.
1784 For any BLOCK node representing a "body block" of a function or method, the
1785 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
1786 represents the outermost (function) scope for the function or method (i.e.
1787 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
1788 *that* node in turn will point to the relevant FUNCTION_DECL node. */
1791 is_body_block (tree stmt)
1793 if (lang_hooks.no_body_blocks)
1796 if (TREE_CODE (stmt) == BLOCK)
1798 tree parent = BLOCK_SUPERCONTEXT (stmt);
1800 if (parent && TREE_CODE (parent) == BLOCK)
1802 tree grandparent = BLOCK_SUPERCONTEXT (parent);
1804 if (grandparent && TREE_CODE (grandparent) == FUNCTION_DECL)
1812 /* Emit code to restore vital registers at the beginning of a nonlocal goto
1815 expand_nl_goto_receiver (void)
1817 /* Clobber the FP when we get here, so we have to make sure it's
1818 marked as used by this function. */
1819 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
1821 /* Mark the static chain as clobbered here so life information
1822 doesn't get messed up for it. */
1823 emit_insn (gen_rtx_CLOBBER (VOIDmode, static_chain_rtx));
1825 #ifdef HAVE_nonlocal_goto
1826 if (! HAVE_nonlocal_goto)
1828 /* First adjust our frame pointer to its actual value. It was
1829 previously set to the start of the virtual area corresponding to
1830 the stacked variables when we branched here and now needs to be
1831 adjusted to the actual hardware fp value.
1833 Assignments are to virtual registers are converted by
1834 instantiate_virtual_regs into the corresponding assignment
1835 to the underlying register (fp in this case) that makes
1836 the original assignment true.
1837 So the following insn will actually be
1838 decrementing fp by STARTING_FRAME_OFFSET. */
1839 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
1841 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
1842 if (fixed_regs[ARG_POINTER_REGNUM])
1844 #ifdef ELIMINABLE_REGS
1845 /* If the argument pointer can be eliminated in favor of the
1846 frame pointer, we don't need to restore it. We assume here
1847 that if such an elimination is present, it can always be used.
1848 This is the case on all known machines; if we don't make this
1849 assumption, we do unnecessary saving on many machines. */
1850 static const struct elims {const int from, to;} elim_regs[] = ELIMINABLE_REGS;
1853 for (i = 0; i < ARRAY_SIZE (elim_regs); i++)
1854 if (elim_regs[i].from == ARG_POINTER_REGNUM
1855 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
1858 if (i == ARRAY_SIZE (elim_regs))
1861 /* Now restore our arg pointer from the address at which it
1862 was saved in our stack frame. */
1863 emit_move_insn (virtual_incoming_args_rtx,
1864 copy_to_reg (get_arg_pointer_save_area (cfun)));
1869 #ifdef HAVE_nonlocal_goto_receiver
1870 if (HAVE_nonlocal_goto_receiver)
1871 emit_insn (gen_nonlocal_goto_receiver ());
1874 /* @@@ This is a kludge. Not all machine descriptions define a blockage
1875 insn, but we must not allow the code we just generated to be reordered
1876 by scheduling. Specifically, the update of the frame pointer must
1877 happen immediately, not later. So emit an ASM_INPUT to act as blockage
1879 emit_insn (gen_rtx_ASM_INPUT (VOIDmode, ""));
1882 /* Generate RTL for the automatic variable declaration DECL.
1883 (Other kinds of declarations are simply ignored if seen here.) */
1886 expand_decl (tree decl)
1890 type = TREE_TYPE (decl);
1892 /* For a CONST_DECL, set mode, alignment, and sizes from those of the
1893 type in case this node is used in a reference. */
1894 if (TREE_CODE (decl) == CONST_DECL)
1896 DECL_MODE (decl) = TYPE_MODE (type);
1897 DECL_ALIGN (decl) = TYPE_ALIGN (type);
1898 DECL_SIZE (decl) = TYPE_SIZE (type);
1899 DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (type);
1903 /* Otherwise, only automatic variables need any expansion done. Static and
1904 external variables, and external functions, will be handled by
1905 `assemble_variable' (called from finish_decl). TYPE_DECL requires
1906 nothing. PARM_DECLs are handled in `assign_parms'. */
1907 if (TREE_CODE (decl) != VAR_DECL)
1910 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
1913 /* Create the RTL representation for the variable. */
1915 if (type == error_mark_node)
1916 SET_DECL_RTL (decl, gen_rtx_MEM (BLKmode, const0_rtx));
1918 else if (DECL_SIZE (decl) == 0)
1919 /* Variable with incomplete type. */
1922 if (DECL_INITIAL (decl) == 0)
1923 /* Error message was already done; now avoid a crash. */
1924 x = gen_rtx_MEM (BLKmode, const0_rtx);
1926 /* An initializer is going to decide the size of this array.
1927 Until we know the size, represent its address with a reg. */
1928 x = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
1930 set_mem_attributes (x, decl, 1);
1931 SET_DECL_RTL (decl, x);
1933 else if (use_register_for_decl (decl))
1935 /* Automatic variable that can go in a register. */
1936 int unsignedp = TYPE_UNSIGNED (type);
1937 enum machine_mode reg_mode
1938 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
1940 SET_DECL_RTL (decl, gen_reg_rtx (reg_mode));
1942 /* Note if the object is a user variable. */
1943 if (!DECL_ARTIFICIAL (decl))
1945 mark_user_reg (DECL_RTL (decl));
1947 /* Trust user variables which have a pointer type to really
1948 be pointers. Do not trust compiler generated temporaries
1949 as our type system is totally busted as it relates to
1950 pointer arithmetic which translates into lots of compiler
1951 generated objects with pointer types, but which are not really
1953 if (POINTER_TYPE_P (type))
1954 mark_reg_pointer (DECL_RTL (decl),
1955 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
1959 else if (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST
1960 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
1961 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl),
1962 STACK_CHECK_MAX_VAR_SIZE)))
1964 /* Variable of fixed size that goes on the stack. */
1969 /* If we previously made RTL for this decl, it must be an array
1970 whose size was determined by the initializer.
1971 The old address was a register; set that register now
1972 to the proper address. */
1973 if (DECL_RTL_SET_P (decl))
1975 gcc_assert (MEM_P (DECL_RTL (decl)));
1976 gcc_assert (REG_P (XEXP (DECL_RTL (decl), 0)));
1977 oldaddr = XEXP (DECL_RTL (decl), 0);
1980 /* Set alignment we actually gave this decl. */
1981 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
1982 : GET_MODE_BITSIZE (DECL_MODE (decl)));
1983 DECL_USER_ALIGN (decl) = 0;
1985 x = assign_temp (decl, 1, 1, 1);
1986 set_mem_attributes (x, decl, 1);
1987 SET_DECL_RTL (decl, x);
1991 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
1992 if (addr != oldaddr)
1993 emit_move_insn (oldaddr, addr);
1997 /* Dynamic-size object: must push space on the stack. */
1999 rtx address, size, x;
2001 /* Record the stack pointer on entry to block, if have
2002 not already done so. */
2003 do_pending_stack_adjust ();
2005 /* Compute the variable's size, in bytes. This will expand any
2006 needed SAVE_EXPRs for the first time. */
2007 size = expand_expr (DECL_SIZE_UNIT (decl), NULL_RTX, VOIDmode, 0);
2010 /* Allocate space on the stack for the variable. Note that
2011 DECL_ALIGN says how the variable is to be aligned and we
2012 cannot use it to conclude anything about the alignment of
2014 address = allocate_dynamic_stack_space (size, NULL_RTX,
2015 TYPE_ALIGN (TREE_TYPE (decl)));
2017 /* Reference the variable indirect through that rtx. */
2018 x = gen_rtx_MEM (DECL_MODE (decl), address);
2019 set_mem_attributes (x, decl, 1);
2020 SET_DECL_RTL (decl, x);
2023 /* Indicate the alignment we actually gave this variable. */
2024 #ifdef STACK_BOUNDARY
2025 DECL_ALIGN (decl) = STACK_BOUNDARY;
2027 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
2029 DECL_USER_ALIGN (decl) = 0;
2033 /* Emit code to save the current value of stack. */
2035 expand_stack_save (void)
2039 do_pending_stack_adjust ();
2040 emit_stack_save (SAVE_BLOCK, &ret, NULL_RTX);
2044 /* Emit code to restore the current value of stack. */
2046 expand_stack_restore (tree var)
2048 rtx sa = DECL_RTL (var);
2050 emit_stack_restore (SAVE_BLOCK, sa, NULL_RTX);
2053 /* Emit code to perform the initialization of a declaration DECL. */
2056 expand_decl_init (tree decl)
2058 int was_used = TREE_USED (decl);
2060 /* If this is a CONST_DECL, we don't have to generate any code. Likewise
2061 for static decls. */
2062 if (TREE_CODE (decl) == CONST_DECL
2063 || TREE_STATIC (decl))
2066 /* Compute and store the initial value now. */
2070 if (DECL_INITIAL (decl) == error_mark_node)
2072 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
2074 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
2075 || code == POINTER_TYPE || code == REFERENCE_TYPE)
2076 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
2079 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
2081 emit_line_note (DECL_SOURCE_LOCATION (decl));
2082 expand_assignment (decl, DECL_INITIAL (decl), 0);
2085 /* Don't let the initialization count as "using" the variable. */
2086 TREE_USED (decl) = was_used;
2088 /* Free any temporaries we made while initializing the decl. */
2089 preserve_temp_slots (NULL_RTX);
2095 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
2096 DECL_ELTS is the list of elements that belong to DECL's type.
2097 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
2100 expand_anon_union_decl (tree decl, tree cleanup ATTRIBUTE_UNUSED,
2106 /* If any of the elements are addressable, so is the entire union. */
2107 for (t = decl_elts; t; t = TREE_CHAIN (t))
2108 if (TREE_ADDRESSABLE (TREE_VALUE (t)))
2110 TREE_ADDRESSABLE (decl) = 1;
2115 x = DECL_RTL (decl);
2117 /* Go through the elements, assigning RTL to each. */
2118 for (t = decl_elts; t; t = TREE_CHAIN (t))
2120 tree decl_elt = TREE_VALUE (t);
2121 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
2124 /* If any of the elements are addressable, so is the entire
2126 if (TREE_USED (decl_elt))
2127 TREE_USED (decl) = 1;
2129 /* Propagate the union's alignment to the elements. */
2130 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
2131 DECL_USER_ALIGN (decl_elt) = DECL_USER_ALIGN (decl);
2133 /* If the element has BLKmode and the union doesn't, the union is
2134 aligned such that the element doesn't need to have BLKmode, so
2135 change the element's mode to the appropriate one for its size. */
2136 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
2137 DECL_MODE (decl_elt) = mode
2138 = mode_for_size_tree (DECL_SIZE (decl_elt), MODE_INT, 1);
2140 if (mode == GET_MODE (x))
2143 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
2144 instead create a new MEM rtx with the proper mode. */
2145 decl_rtl = adjust_address_nv (x, mode, 0);
2148 gcc_assert (REG_P (x));
2149 decl_rtl = gen_lowpart_SUBREG (mode, x);
2151 SET_DECL_RTL (decl_elt, decl_rtl);
2155 /* Do the insertion of a case label into case_list. The labels are
2156 fed to us in descending order from the sorted vector of case labels used
2157 in the tree part of the middle end. So the list we construct is
2158 sorted in ascending order. */
2161 add_case_node (struct case_node *head, tree low, tree high, tree label)
2163 struct case_node *r;
2165 /* If there's no HIGH value, then this is not a case range; it's
2166 just a simple case label. But that's just a degenerate case
2168 If the bounds are equal, turn this into the one-value case. */
2169 if (!high || tree_int_cst_equal (low, high))
2172 /* Add this label to the chain. */
2173 r = ggc_alloc (sizeof (struct case_node));
2176 r->code_label = label;
2177 r->parent = r->left = NULL;
2182 /* Maximum number of case bit tests. */
2183 #define MAX_CASE_BIT_TESTS 3
2185 /* By default, enable case bit tests on targets with ashlsi3. */
2186 #ifndef CASE_USE_BIT_TESTS
2187 #define CASE_USE_BIT_TESTS (ashl_optab->handlers[word_mode].insn_code \
2188 != CODE_FOR_nothing)
2192 /* A case_bit_test represents a set of case nodes that may be
2193 selected from using a bit-wise comparison. HI and LO hold
2194 the integer to be tested against, LABEL contains the label
2195 to jump to upon success and BITS counts the number of case
2196 nodes handled by this test, typically the number of bits
2199 struct case_bit_test
2207 /* Determine whether "1 << x" is relatively cheap in word_mode. */
2210 bool lshift_cheap_p (void)
2212 static bool init = false;
2213 static bool cheap = true;
2217 rtx reg = gen_rtx_REG (word_mode, 10000);
2218 int cost = rtx_cost (gen_rtx_ASHIFT (word_mode, const1_rtx, reg), SET);
2219 cheap = cost < COSTS_N_INSNS (3);
2226 /* Comparison function for qsort to order bit tests by decreasing
2227 number of case nodes, i.e. the node with the most cases gets
2231 case_bit_test_cmp (const void *p1, const void *p2)
2233 const struct case_bit_test *d1 = p1;
2234 const struct case_bit_test *d2 = p2;
2236 return d2->bits - d1->bits;
2239 /* Expand a switch statement by a short sequence of bit-wise
2240 comparisons. "switch(x)" is effectively converted into
2241 "if ((1 << (x-MINVAL)) & CST)" where CST and MINVAL are
2244 INDEX_EXPR is the value being switched on, which is of
2245 type INDEX_TYPE. MINVAL is the lowest case value of in
2246 the case nodes, of INDEX_TYPE type, and RANGE is highest
2247 value minus MINVAL, also of type INDEX_TYPE. NODES is
2248 the set of case nodes, and DEFAULT_LABEL is the label to
2249 branch to should none of the cases match.
2251 There *MUST* be MAX_CASE_BIT_TESTS or less unique case
2255 emit_case_bit_tests (tree index_type, tree index_expr, tree minval,
2256 tree range, case_node_ptr nodes, rtx default_label)
2258 struct case_bit_test test[MAX_CASE_BIT_TESTS];
2259 enum machine_mode mode;
2260 rtx expr, index, label;
2261 unsigned int i,j,lo,hi;
2262 struct case_node *n;
2266 for (n = nodes; n; n = n->right)
2268 label = label_rtx (n->code_label);
2269 for (i = 0; i < count; i++)
2270 if (label == test[i].label)
2275 gcc_assert (count < MAX_CASE_BIT_TESTS);
2278 test[i].label = label;
2285 lo = tree_low_cst (fold (build2 (MINUS_EXPR, index_type,
2286 n->low, minval)), 1);
2287 hi = tree_low_cst (fold (build2 (MINUS_EXPR, index_type,
2288 n->high, minval)), 1);
2289 for (j = lo; j <= hi; j++)
2290 if (j >= HOST_BITS_PER_WIDE_INT)
2291 test[i].hi |= (HOST_WIDE_INT) 1 << (j - HOST_BITS_PER_INT);
2293 test[i].lo |= (HOST_WIDE_INT) 1 << j;
2296 qsort (test, count, sizeof(*test), case_bit_test_cmp);
2298 index_expr = fold (build2 (MINUS_EXPR, index_type,
2299 convert (index_type, index_expr),
2300 convert (index_type, minval)));
2301 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
2302 do_pending_stack_adjust ();
2304 mode = TYPE_MODE (index_type);
2305 expr = expand_expr (range, NULL_RTX, VOIDmode, 0);
2306 emit_cmp_and_jump_insns (index, expr, GTU, NULL_RTX, mode, 1,
2309 index = convert_to_mode (word_mode, index, 0);
2310 index = expand_binop (word_mode, ashl_optab, const1_rtx,
2311 index, NULL_RTX, 1, OPTAB_WIDEN);
2313 for (i = 0; i < count; i++)
2315 expr = immed_double_const (test[i].lo, test[i].hi, word_mode);
2316 expr = expand_binop (word_mode, and_optab, index, expr,
2317 NULL_RTX, 1, OPTAB_WIDEN);
2318 emit_cmp_and_jump_insns (expr, const0_rtx, NE, NULL_RTX,
2319 word_mode, 1, test[i].label);
2322 emit_jump (default_label);
2326 #define HAVE_casesi 0
2329 #ifndef HAVE_tablejump
2330 #define HAVE_tablejump 0
2333 /* Terminate a case (Pascal) or switch (C) statement
2334 in which ORIG_INDEX is the expression to be tested.
2335 If ORIG_TYPE is not NULL, it is the original ORIG_INDEX
2336 type as given in the source before any compiler conversions.
2337 Generate the code to test it and jump to the right place. */
2340 expand_case (tree exp)
2342 tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE;
2343 rtx default_label = 0;
2344 struct case_node *n, *m;
2345 unsigned int count, uniq;
2351 rtx before_case, end, lab;
2353 tree vec = SWITCH_LABELS (exp);
2354 tree orig_type = TREE_TYPE (exp);
2355 tree index_expr = SWITCH_COND (exp);
2356 tree index_type = TREE_TYPE (index_expr);
2357 int unsignedp = TYPE_UNSIGNED (index_type);
2359 /* The insn after which the case dispatch should finally
2360 be emitted. Zero for a dummy. */
2363 /* A list of case labels; it is first built as a list and it may then
2364 be rearranged into a nearly balanced binary tree. */
2365 struct case_node *case_list = 0;
2367 /* Label to jump to if no case matches. */
2368 tree default_label_decl = 0;
2370 /* The switch body is lowered in gimplify.c, we should never have
2371 switches with a non-NULL SWITCH_BODY here. */
2372 gcc_assert (!SWITCH_BODY (exp));
2373 gcc_assert (SWITCH_LABELS (exp));
2375 for (i = TREE_VEC_LENGTH (vec); --i >= 0; )
2377 tree elt = TREE_VEC_ELT (vec, i);
2379 /* Handle default labels specially. */
2380 if (!CASE_HIGH (elt) && !CASE_LOW (elt))
2382 gcc_assert (!default_label_decl);
2383 default_label_decl = CASE_LABEL (elt);
2386 case_list = add_case_node (case_list, CASE_LOW (elt), CASE_HIGH (elt),
2390 do_pending_stack_adjust ();
2392 /* Make sure start points to something that won't need any transformation
2393 before the end of this function. */
2394 if (!NOTE_P (get_last_insn ()))
2395 emit_note (NOTE_INSN_DELETED);
2397 start = get_last_insn ();
2399 /* An ERROR_MARK occurs for various reasons including invalid data type. */
2400 if (index_type != error_mark_node)
2404 /* If we don't have a default-label, create one here,
2405 after the body of the switch. */
2406 if (default_label_decl == 0)
2409 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
2410 expand_label (default_label_decl);
2412 default_label = label_rtx (default_label_decl);
2414 before_case = get_last_insn ();
2416 /* Get upper and lower bounds of case values.
2417 Also convert all the case values to the index expr's data type. */
2421 for (n = case_list; n; n = n->right)
2423 /* Check low and high label values are integers. */
2424 gcc_assert (TREE_CODE (n->low) == INTEGER_CST);
2425 gcc_assert (TREE_CODE (n->high) == INTEGER_CST);
2427 n->low = convert (index_type, n->low);
2428 n->high = convert (index_type, n->high);
2430 /* Count the elements and track the largest and smallest
2431 of them (treating them as signed even if they are not). */
2439 if (INT_CST_LT (n->low, minval))
2441 if (INT_CST_LT (maxval, n->high))
2444 /* A range counts double, since it requires two compares. */
2445 if (! tree_int_cst_equal (n->low, n->high))
2448 /* Count the number of unique case node targets. */
2450 lab = label_rtx (n->code_label);
2451 for (m = case_list; m != n; m = m->right)
2452 if (label_rtx (m->code_label) == lab)
2459 /* Compute span of values. */
2461 range = fold (build2 (MINUS_EXPR, index_type, maxval, minval));
2465 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
2466 emit_jump (default_label);
2469 /* Try implementing this switch statement by a short sequence of
2470 bit-wise comparisons. However, we let the binary-tree case
2471 below handle constant index expressions. */
2472 else if (CASE_USE_BIT_TESTS
2473 && ! TREE_CONSTANT (index_expr)
2474 && compare_tree_int (range, GET_MODE_BITSIZE (word_mode)) < 0
2475 && compare_tree_int (range, 0) > 0
2476 && lshift_cheap_p ()
2477 && ((uniq == 1 && count >= 3)
2478 || (uniq == 2 && count >= 5)
2479 || (uniq == 3 && count >= 6)))
2481 /* Optimize the case where all the case values fit in a
2482 word without having to subtract MINVAL. In this case,
2483 we can optimize away the subtraction. */
2484 if (compare_tree_int (minval, 0) > 0
2485 && compare_tree_int (maxval, GET_MODE_BITSIZE (word_mode)) < 0)
2487 minval = integer_zero_node;
2490 emit_case_bit_tests (index_type, index_expr, minval, range,
2491 case_list, default_label);
2494 /* If range of values is much bigger than number of values,
2495 make a sequence of conditional branches instead of a dispatch.
2496 If the switch-index is a constant, do it this way
2497 because we can optimize it. */
2499 else if (count < case_values_threshold ()
2500 || compare_tree_int (range,
2501 (optimize_size ? 3 : 10) * count) > 0
2502 /* RANGE may be signed, and really large ranges will show up
2503 as negative numbers. */
2504 || compare_tree_int (range, 0) < 0
2505 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
2508 || TREE_CONSTANT (index_expr)
2509 /* If neither casesi or tablejump is available, we can
2510 only go this way. */
2511 || (!HAVE_casesi && !HAVE_tablejump))
2513 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
2515 /* If the index is a short or char that we do not have
2516 an insn to handle comparisons directly, convert it to
2517 a full integer now, rather than letting each comparison
2518 generate the conversion. */
2520 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
2521 && ! have_insn_for (COMPARE, GET_MODE (index)))
2523 enum machine_mode wider_mode;
2524 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
2525 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
2526 if (have_insn_for (COMPARE, wider_mode))
2528 index = convert_to_mode (wider_mode, index, unsignedp);
2533 do_pending_stack_adjust ();
2536 index = copy_to_reg (index);
2537 if (GET_CODE (index) == CONST_INT
2538 || TREE_CODE (index_expr) == INTEGER_CST)
2540 /* Make a tree node with the proper constant value
2541 if we don't already have one. */
2542 if (TREE_CODE (index_expr) != INTEGER_CST)
2545 = build_int_cst_wide (NULL_TREE, INTVAL (index),
2546 unsignedp || INTVAL (index) >= 0
2548 index_expr = convert (index_type, index_expr);
2551 /* For constant index expressions we need only
2552 issue an unconditional branch to the appropriate
2553 target code. The job of removing any unreachable
2554 code is left to the optimization phase if the
2555 "-O" option is specified. */
2556 for (n = case_list; n; n = n->right)
2557 if (! tree_int_cst_lt (index_expr, n->low)
2558 && ! tree_int_cst_lt (n->high, index_expr))
2562 emit_jump (label_rtx (n->code_label));
2564 emit_jump (default_label);
2568 /* If the index expression is not constant we generate
2569 a binary decision tree to select the appropriate
2570 target code. This is done as follows:
2572 The list of cases is rearranged into a binary tree,
2573 nearly optimal assuming equal probability for each case.
2575 The tree is transformed into RTL, eliminating
2576 redundant test conditions at the same time.
2578 If program flow could reach the end of the
2579 decision tree an unconditional jump to the
2580 default code is emitted. */
2583 = (TREE_CODE (orig_type) != ENUMERAL_TYPE
2584 && estimate_case_costs (case_list));
2585 balance_case_nodes (&case_list, NULL);
2586 emit_case_nodes (index, case_list, default_label, index_type);
2587 emit_jump (default_label);
2592 table_label = gen_label_rtx ();
2593 if (! try_casesi (index_type, index_expr, minval, range,
2594 table_label, default_label))
2597 index_type = integer_type_node;
2599 /* Index jumptables from zero for suitable values of
2600 minval to avoid a subtraction. */
2602 && compare_tree_int (minval, 0) > 0
2603 && compare_tree_int (minval, 3) < 0)
2605 minval = integer_zero_node;
2609 ok = try_tablejump (index_type, index_expr, minval, range,
2610 table_label, default_label);
2614 /* Get table of labels to jump to, in order of case index. */
2616 ncases = tree_low_cst (range, 0) + 1;
2617 labelvec = alloca (ncases * sizeof (rtx));
2618 memset (labelvec, 0, ncases * sizeof (rtx));
2620 for (n = case_list; n; n = n->right)
2622 /* Compute the low and high bounds relative to the minimum
2623 value since that should fit in a HOST_WIDE_INT while the
2624 actual values may not. */
2626 = tree_low_cst (fold (build2 (MINUS_EXPR, index_type,
2627 n->low, minval)), 1);
2628 HOST_WIDE_INT i_high
2629 = tree_low_cst (fold (build2 (MINUS_EXPR, index_type,
2630 n->high, minval)), 1);
2633 for (i = i_low; i <= i_high; i ++)
2635 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
2638 /* Fill in the gaps with the default. */
2639 for (i = 0; i < ncases; i++)
2640 if (labelvec[i] == 0)
2641 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
2643 /* Output the table. */
2644 emit_label (table_label);
2646 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
2647 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
2648 gen_rtx_LABEL_REF (Pmode, table_label),
2649 gen_rtvec_v (ncases, labelvec),
2650 const0_rtx, const0_rtx));
2652 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
2653 gen_rtvec_v (ncases, labelvec)));
2655 /* If the case insn drops through the table,
2656 after the table we must jump to the default-label.
2657 Otherwise record no drop-through after the table. */
2658 #ifdef CASE_DROPS_THROUGH
2659 emit_jump (default_label);
2665 before_case = NEXT_INSN (before_case);
2666 end = get_last_insn ();
2667 fail = squeeze_notes (&before_case, &end);
2669 reorder_insns (before_case, end, start);
2675 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
2678 do_jump_if_equal (rtx op1, rtx op2, rtx label, int unsignedp)
2680 if (GET_CODE (op1) == CONST_INT && GET_CODE (op2) == CONST_INT)
2686 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX,
2687 (GET_MODE (op1) == VOIDmode
2688 ? GET_MODE (op2) : GET_MODE (op1)),
2692 /* Not all case values are encountered equally. This function
2693 uses a heuristic to weight case labels, in cases where that
2694 looks like a reasonable thing to do.
2696 Right now, all we try to guess is text, and we establish the
2699 chars above space: 16
2708 If we find any cases in the switch that are not either -1 or in the range
2709 of valid ASCII characters, or are control characters other than those
2710 commonly used with "\", don't treat this switch scanning text.
2712 Return 1 if these nodes are suitable for cost estimation, otherwise
2716 estimate_case_costs (case_node_ptr node)
2718 tree min_ascii = integer_minus_one_node;
2719 tree max_ascii = convert (TREE_TYPE (node->high),
2720 build_int_cst (NULL_TREE, 127));
2724 /* If we haven't already made the cost table, make it now. Note that the
2725 lower bound of the table is -1, not zero. */
2727 if (! cost_table_initialized)
2729 cost_table_initialized = 1;
2731 for (i = 0; i < 128; i++)
2734 COST_TABLE (i) = 16;
2735 else if (ISPUNCT (i))
2737 else if (ISCNTRL (i))
2738 COST_TABLE (i) = -1;
2741 COST_TABLE (' ') = 8;
2742 COST_TABLE ('\t') = 4;
2743 COST_TABLE ('\0') = 4;
2744 COST_TABLE ('\n') = 2;
2745 COST_TABLE ('\f') = 1;
2746 COST_TABLE ('\v') = 1;
2747 COST_TABLE ('\b') = 1;
2750 /* See if all the case expressions look like text. It is text if the
2751 constant is >= -1 and the highest constant is <= 127. Do all comparisons
2752 as signed arithmetic since we don't want to ever access cost_table with a
2753 value less than -1. Also check that none of the constants in a range
2754 are strange control characters. */
2756 for (n = node; n; n = n->right)
2758 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
2761 for (i = (HOST_WIDE_INT) TREE_INT_CST_LOW (n->low);
2762 i <= (HOST_WIDE_INT) TREE_INT_CST_LOW (n->high); i++)
2763 if (COST_TABLE (i) < 0)
2767 /* All interesting values are within the range of interesting
2768 ASCII characters. */
2772 /* Take an ordered list of case nodes
2773 and transform them into a near optimal binary tree,
2774 on the assumption that any target code selection value is as
2775 likely as any other.
2777 The transformation is performed by splitting the ordered
2778 list into two equal sections plus a pivot. The parts are
2779 then attached to the pivot as left and right branches. Each
2780 branch is then transformed recursively. */
2783 balance_case_nodes (case_node_ptr *head, case_node_ptr parent)
2796 /* Count the number of entries on branch. Also count the ranges. */
2800 if (!tree_int_cst_equal (np->low, np->high))
2804 cost += COST_TABLE (TREE_INT_CST_LOW (np->high));
2808 cost += COST_TABLE (TREE_INT_CST_LOW (np->low));
2816 /* Split this list if it is long enough for that to help. */
2821 /* Find the place in the list that bisects the list's total cost,
2822 Here I gets half the total cost. */
2827 /* Skip nodes while their cost does not reach that amount. */
2828 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
2829 i -= COST_TABLE (TREE_INT_CST_LOW ((*npp)->high));
2830 i -= COST_TABLE (TREE_INT_CST_LOW ((*npp)->low));
2833 npp = &(*npp)->right;
2838 /* Leave this branch lopsided, but optimize left-hand
2839 side and fill in `parent' fields for right-hand side. */
2841 np->parent = parent;
2842 balance_case_nodes (&np->left, np);
2843 for (; np->right; np = np->right)
2844 np->right->parent = np;
2848 /* If there are just three nodes, split at the middle one. */
2850 npp = &(*npp)->right;
2853 /* Find the place in the list that bisects the list's total cost,
2854 where ranges count as 2.
2855 Here I gets half the total cost. */
2856 i = (i + ranges + 1) / 2;
2859 /* Skip nodes while their cost does not reach that amount. */
2860 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
2865 npp = &(*npp)->right;
2870 np->parent = parent;
2873 /* Optimize each of the two split parts. */
2874 balance_case_nodes (&np->left, np);
2875 balance_case_nodes (&np->right, np);
2879 /* Else leave this branch as one level,
2880 but fill in `parent' fields. */
2882 np->parent = parent;
2883 for (; np->right; np = np->right)
2884 np->right->parent = np;
2889 /* Search the parent sections of the case node tree
2890 to see if a test for the lower bound of NODE would be redundant.
2891 INDEX_TYPE is the type of the index expression.
2893 The instructions to generate the case decision tree are
2894 output in the same order as nodes are processed so it is
2895 known that if a parent node checks the range of the current
2896 node minus one that the current node is bounded at its lower
2897 span. Thus the test would be redundant. */
2900 node_has_low_bound (case_node_ptr node, tree index_type)
2903 case_node_ptr pnode;
2905 /* If the lower bound of this node is the lowest value in the index type,
2906 we need not test it. */
2908 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
2911 /* If this node has a left branch, the value at the left must be less
2912 than that at this node, so it cannot be bounded at the bottom and
2913 we need not bother testing any further. */
2918 low_minus_one = fold (build2 (MINUS_EXPR, TREE_TYPE (node->low),
2919 node->low, integer_one_node));
2921 /* If the subtraction above overflowed, we can't verify anything.
2922 Otherwise, look for a parent that tests our value - 1. */
2924 if (! tree_int_cst_lt (low_minus_one, node->low))
2927 for (pnode = node->parent; pnode; pnode = pnode->parent)
2928 if (tree_int_cst_equal (low_minus_one, pnode->high))
2934 /* Search the parent sections of the case node tree
2935 to see if a test for the upper bound of NODE would be redundant.
2936 INDEX_TYPE is the type of the index expression.
2938 The instructions to generate the case decision tree are
2939 output in the same order as nodes are processed so it is
2940 known that if a parent node checks the range of the current
2941 node plus one that the current node is bounded at its upper
2942 span. Thus the test would be redundant. */
2945 node_has_high_bound (case_node_ptr node, tree index_type)
2948 case_node_ptr pnode;
2950 /* If there is no upper bound, obviously no test is needed. */
2952 if (TYPE_MAX_VALUE (index_type) == NULL)
2955 /* If the upper bound of this node is the highest value in the type
2956 of the index expression, we need not test against it. */
2958 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
2961 /* If this node has a right branch, the value at the right must be greater
2962 than that at this node, so it cannot be bounded at the top and
2963 we need not bother testing any further. */
2968 high_plus_one = fold (build2 (PLUS_EXPR, TREE_TYPE (node->high),
2969 node->high, integer_one_node));
2971 /* If the addition above overflowed, we can't verify anything.
2972 Otherwise, look for a parent that tests our value + 1. */
2974 if (! tree_int_cst_lt (node->high, high_plus_one))
2977 for (pnode = node->parent; pnode; pnode = pnode->parent)
2978 if (tree_int_cst_equal (high_plus_one, pnode->low))
2984 /* Search the parent sections of the
2985 case node tree to see if both tests for the upper and lower
2986 bounds of NODE would be redundant. */
2989 node_is_bounded (case_node_ptr node, tree index_type)
2991 return (node_has_low_bound (node, index_type)
2992 && node_has_high_bound (node, index_type));
2995 /* Emit step-by-step code to select a case for the value of INDEX.
2996 The thus generated decision tree follows the form of the
2997 case-node binary tree NODE, whose nodes represent test conditions.
2998 INDEX_TYPE is the type of the index of the switch.
3000 Care is taken to prune redundant tests from the decision tree
3001 by detecting any boundary conditions already checked by
3002 emitted rtx. (See node_has_high_bound, node_has_low_bound
3003 and node_is_bounded, above.)
3005 Where the test conditions can be shown to be redundant we emit
3006 an unconditional jump to the target code. As a further
3007 optimization, the subordinates of a tree node are examined to
3008 check for bounded nodes. In this case conditional and/or
3009 unconditional jumps as a result of the boundary check for the
3010 current node are arranged to target the subordinates associated
3011 code for out of bound conditions on the current node.
3013 We can assume that when control reaches the code generated here,
3014 the index value has already been compared with the parents
3015 of this node, and determined to be on the same side of each parent
3016 as this node is. Thus, if this node tests for the value 51,
3017 and a parent tested for 52, we don't need to consider
3018 the possibility of a value greater than 51. If another parent
3019 tests for the value 50, then this node need not test anything. */
3022 emit_case_nodes (rtx index, case_node_ptr node, rtx default_label,
3025 /* If INDEX has an unsigned type, we must make unsigned branches. */
3026 int unsignedp = TYPE_UNSIGNED (index_type);
3027 enum machine_mode mode = GET_MODE (index);
3028 enum machine_mode imode = TYPE_MODE (index_type);
3030 /* See if our parents have already tested everything for us.
3031 If they have, emit an unconditional jump for this node. */
3032 if (node_is_bounded (node, index_type))
3033 emit_jump (label_rtx (node->code_label));
3035 else if (tree_int_cst_equal (node->low, node->high))
3037 /* Node is single valued. First see if the index expression matches
3038 this node and then check our children, if any. */
3040 do_jump_if_equal (index,
3041 convert_modes (mode, imode,
3042 expand_expr (node->low, NULL_RTX,
3045 label_rtx (node->code_label), unsignedp);
3047 if (node->right != 0 && node->left != 0)
3049 /* This node has children on both sides.
3050 Dispatch to one side or the other
3051 by comparing the index value with this node's value.
3052 If one subtree is bounded, check that one first,
3053 so we can avoid real branches in the tree. */
3055 if (node_is_bounded (node->right, index_type))
3057 emit_cmp_and_jump_insns (index,
3060 expand_expr (node->high, NULL_RTX,
3063 GT, NULL_RTX, mode, unsignedp,
3064 label_rtx (node->right->code_label));
3065 emit_case_nodes (index, node->left, default_label, index_type);
3068 else if (node_is_bounded (node->left, index_type))
3070 emit_cmp_and_jump_insns (index,
3073 expand_expr (node->high, NULL_RTX,
3076 LT, NULL_RTX, mode, unsignedp,
3077 label_rtx (node->left->code_label));
3078 emit_case_nodes (index, node->right, default_label, index_type);
3081 /* If both children are single-valued cases with no
3082 children, finish up all the work. This way, we can save
3083 one ordered comparison. */
3084 else if (tree_int_cst_equal (node->right->low, node->right->high)
3085 && node->right->left == 0
3086 && node->right->right == 0
3087 && tree_int_cst_equal (node->left->low, node->left->high)
3088 && node->left->left == 0
3089 && node->left->right == 0)
3091 /* Neither node is bounded. First distinguish the two sides;
3092 then emit the code for one side at a time. */
3094 /* See if the value matches what the right hand side
3096 do_jump_if_equal (index,
3097 convert_modes (mode, imode,
3098 expand_expr (node->right->low,
3102 label_rtx (node->right->code_label),
3105 /* See if the value matches what the left hand side
3107 do_jump_if_equal (index,
3108 convert_modes (mode, imode,
3109 expand_expr (node->left->low,
3113 label_rtx (node->left->code_label),
3119 /* Neither node is bounded. First distinguish the two sides;
3120 then emit the code for one side at a time. */
3122 tree test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
3124 /* See if the value is on the right. */
3125 emit_cmp_and_jump_insns (index,
3128 expand_expr (node->high, NULL_RTX,
3131 GT, NULL_RTX, mode, unsignedp,
3132 label_rtx (test_label));
3134 /* Value must be on the left.
3135 Handle the left-hand subtree. */
3136 emit_case_nodes (index, node->left, default_label, index_type);
3137 /* If left-hand subtree does nothing,
3139 emit_jump (default_label);
3141 /* Code branches here for the right-hand subtree. */
3142 expand_label (test_label);
3143 emit_case_nodes (index, node->right, default_label, index_type);
3147 else if (node->right != 0 && node->left == 0)
3149 /* Here we have a right child but no left so we issue conditional
3150 branch to default and process the right child.
3152 Omit the conditional branch to default if we it avoid only one
3153 right child; it costs too much space to save so little time. */
3155 if (node->right->right || node->right->left
3156 || !tree_int_cst_equal (node->right->low, node->right->high))
3158 if (!node_has_low_bound (node, index_type))
3160 emit_cmp_and_jump_insns (index,
3163 expand_expr (node->high, NULL_RTX,
3166 LT, NULL_RTX, mode, unsignedp,
3170 emit_case_nodes (index, node->right, default_label, index_type);
3173 /* We cannot process node->right normally
3174 since we haven't ruled out the numbers less than
3175 this node's value. So handle node->right explicitly. */
3176 do_jump_if_equal (index,
3179 expand_expr (node->right->low, NULL_RTX,
3182 label_rtx (node->right->code_label), unsignedp);
3185 else if (node->right == 0 && node->left != 0)
3187 /* Just one subtree, on the left. */
3188 if (node->left->left || node->left->right
3189 || !tree_int_cst_equal (node->left->low, node->left->high))
3191 if (!node_has_high_bound (node, index_type))
3193 emit_cmp_and_jump_insns (index,
3196 expand_expr (node->high, NULL_RTX,
3199 GT, NULL_RTX, mode, unsignedp,
3203 emit_case_nodes (index, node->left, default_label, index_type);
3206 /* We cannot process node->left normally
3207 since we haven't ruled out the numbers less than
3208 this node's value. So handle node->left explicitly. */
3209 do_jump_if_equal (index,
3212 expand_expr (node->left->low, NULL_RTX,
3215 label_rtx (node->left->code_label), unsignedp);
3220 /* Node is a range. These cases are very similar to those for a single
3221 value, except that we do not start by testing whether this node
3222 is the one to branch to. */
3224 if (node->right != 0 && node->left != 0)
3226 /* Node has subtrees on both sides.
3227 If the right-hand subtree is bounded,
3228 test for it first, since we can go straight there.
3229 Otherwise, we need to make a branch in the control structure,
3230 then handle the two subtrees. */
3231 tree test_label = 0;
3233 if (node_is_bounded (node->right, index_type))
3234 /* Right hand node is fully bounded so we can eliminate any
3235 testing and branch directly to the target code. */
3236 emit_cmp_and_jump_insns (index,
3239 expand_expr (node->high, NULL_RTX,
3242 GT, NULL_RTX, mode, unsignedp,
3243 label_rtx (node->right->code_label));
3246 /* Right hand node requires testing.
3247 Branch to a label where we will handle it later. */
3249 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
3250 emit_cmp_and_jump_insns (index,
3253 expand_expr (node->high, NULL_RTX,
3256 GT, NULL_RTX, mode, unsignedp,
3257 label_rtx (test_label));
3260 /* Value belongs to this node or to the left-hand subtree. */
3262 emit_cmp_and_jump_insns (index,
3265 expand_expr (node->low, NULL_RTX,
3268 GE, NULL_RTX, mode, unsignedp,
3269 label_rtx (node->code_label));
3271 /* Handle the left-hand subtree. */
3272 emit_case_nodes (index, node->left, default_label, index_type);
3274 /* If right node had to be handled later, do that now. */
3278 /* If the left-hand subtree fell through,
3279 don't let it fall into the right-hand subtree. */
3280 emit_jump (default_label);
3282 expand_label (test_label);
3283 emit_case_nodes (index, node->right, default_label, index_type);
3287 else if (node->right != 0 && node->left == 0)
3289 /* Deal with values to the left of this node,
3290 if they are possible. */
3291 if (!node_has_low_bound (node, index_type))
3293 emit_cmp_and_jump_insns (index,
3296 expand_expr (node->low, NULL_RTX,
3299 LT, NULL_RTX, mode, unsignedp,
3303 /* Value belongs to this node or to the right-hand subtree. */
3305 emit_cmp_and_jump_insns (index,
3308 expand_expr (node->high, NULL_RTX,
3311 LE, NULL_RTX, mode, unsignedp,
3312 label_rtx (node->code_label));
3314 emit_case_nodes (index, node->right, default_label, index_type);
3317 else if (node->right == 0 && node->left != 0)
3319 /* Deal with values to the right of this node,
3320 if they are possible. */
3321 if (!node_has_high_bound (node, index_type))
3323 emit_cmp_and_jump_insns (index,
3326 expand_expr (node->high, NULL_RTX,
3329 GT, NULL_RTX, mode, unsignedp,
3333 /* Value belongs to this node or to the left-hand subtree. */
3335 emit_cmp_and_jump_insns (index,
3338 expand_expr (node->low, NULL_RTX,
3341 GE, NULL_RTX, mode, unsignedp,
3342 label_rtx (node->code_label));
3344 emit_case_nodes (index, node->left, default_label, index_type);
3349 /* Node has no children so we check low and high bounds to remove
3350 redundant tests. Only one of the bounds can exist,
3351 since otherwise this node is bounded--a case tested already. */
3352 int high_bound = node_has_high_bound (node, index_type);
3353 int low_bound = node_has_low_bound (node, index_type);
3355 if (!high_bound && low_bound)
3357 emit_cmp_and_jump_insns (index,
3360 expand_expr (node->high, NULL_RTX,
3363 GT, NULL_RTX, mode, unsignedp,
3367 else if (!low_bound && high_bound)
3369 emit_cmp_and_jump_insns (index,
3372 expand_expr (node->low, NULL_RTX,
3375 LT, NULL_RTX, mode, unsignedp,
3378 else if (!low_bound && !high_bound)
3380 /* Widen LOW and HIGH to the same width as INDEX. */
3381 tree type = lang_hooks.types.type_for_mode (mode, unsignedp);
3382 tree low = build1 (CONVERT_EXPR, type, node->low);
3383 tree high = build1 (CONVERT_EXPR, type, node->high);
3384 rtx low_rtx, new_index, new_bound;
3386 /* Instead of doing two branches, emit one unsigned branch for
3387 (index-low) > (high-low). */
3388 low_rtx = expand_expr (low, NULL_RTX, mode, 0);
3389 new_index = expand_simple_binop (mode, MINUS, index, low_rtx,
3390 NULL_RTX, unsignedp,
3392 new_bound = expand_expr (fold (build2 (MINUS_EXPR, type,
3396 emit_cmp_and_jump_insns (new_index, new_bound, GT, NULL_RTX,
3397 mode, 1, default_label);
3400 emit_jump (label_rtx (node->code_label));