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"
48 #include "langhooks.h"
54 /* Functions and data structures for expanding case statements. */
56 /* Case label structure, used to hold info on labels within case
57 statements. We handle "range" labels; for a single-value label
58 as in C, the high and low limits are the same.
60 We start with a vector of case nodes sorted in ascending order, and
61 the default label as the last element in the vector. Before expanding
62 to RTL, we transform this vector into a list linked via the RIGHT
63 fields in the case_node struct. Nodes with higher case values are
66 Switch statements can be output in three forms. A branch table is
67 used if there are more than a few labels and the labels are dense
68 within the range between the smallest and largest case value. If a
69 branch table is used, no further manipulations are done with the case
72 The alternative to the use of a branch table is to generate a series
73 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
74 and PARENT fields to hold a binary tree. Initially the tree is
75 totally unbalanced, with everything on the right. We balance the tree
76 with nodes on the left having lower case values than the parent
77 and nodes on the right having higher values. We then output the tree
80 For very small, suitable switch statements, we can generate a series
81 of simple bit test and branches instead. */
83 struct case_node GTY(())
85 struct case_node *left; /* Left son in binary tree */
86 struct case_node *right; /* Right son in binary tree; also node chain */
87 struct case_node *parent; /* Parent of node in binary tree */
88 tree low; /* Lowest index value for this label */
89 tree high; /* Highest index value for this label */
90 tree code_label; /* Label to jump to when node matches */
93 typedef struct case_node case_node;
94 typedef struct case_node *case_node_ptr;
96 /* These are used by estimate_case_costs and balance_case_nodes. */
98 /* This must be a signed type, and non-ANSI compilers lack signed char. */
99 static short cost_table_[129];
100 static int use_cost_table;
101 static int cost_table_initialized;
103 /* Special care is needed because we allow -1, but TREE_INT_CST_LOW
105 #define COST_TABLE(I) cost_table_[(unsigned HOST_WIDE_INT) ((I) + 1)]
107 static int n_occurrences (int, const char *);
108 static bool decl_conflicts_with_clobbers_p (tree, const HARD_REG_SET);
109 static void expand_nl_goto_receiver (void);
110 static bool check_operand_nalternatives (tree, tree);
111 static bool check_unique_operand_names (tree, tree);
112 static char *resolve_operand_name_1 (char *, tree, tree);
113 static void expand_null_return_1 (void);
114 static rtx shift_return_value (rtx);
115 static void expand_value_return (rtx);
116 static void do_jump_if_equal (rtx, rtx, rtx, int);
117 static int estimate_case_costs (case_node_ptr);
118 static bool lshift_cheap_p (void);
119 static int case_bit_test_cmp (const void *, const void *);
120 static void emit_case_bit_tests (tree, tree, tree, tree, case_node_ptr, rtx);
121 static void balance_case_nodes (case_node_ptr *, case_node_ptr);
122 static int node_has_low_bound (case_node_ptr, tree);
123 static int node_has_high_bound (case_node_ptr, tree);
124 static int node_is_bounded (case_node_ptr, tree);
125 static void emit_case_nodes (rtx, case_node_ptr, rtx, tree);
126 static struct case_node *add_case_node (struct case_node *, tree, tree, tree);
129 /* Return the rtx-label that corresponds to a LABEL_DECL,
130 creating it if necessary. */
133 label_rtx (tree label)
135 if (TREE_CODE (label) != LABEL_DECL)
138 if (!DECL_RTL_SET_P (label))
140 rtx r = gen_label_rtx ();
141 SET_DECL_RTL (label, r);
142 if (FORCED_LABEL (label) || DECL_NONLOCAL (label))
143 LABEL_PRESERVE_P (r) = 1;
146 return DECL_RTL (label);
149 /* As above, but also put it on the forced-reference list of the
150 function that contains it. */
152 force_label_rtx (tree label)
154 rtx ref = label_rtx (label);
155 tree function = decl_function_context (label);
161 if (function != current_function_decl)
162 p = find_function_data (function);
166 p->expr->x_forced_labels = gen_rtx_EXPR_LIST (VOIDmode, ref,
167 p->expr->x_forced_labels);
171 /* Add an unconditional jump to LABEL as the next sequential instruction. */
174 emit_jump (rtx label)
176 do_pending_stack_adjust ();
177 emit_jump_insn (gen_jump (label));
181 /* Emit code to jump to the address
182 specified by the pointer expression EXP. */
185 expand_computed_goto (tree exp)
187 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
189 x = convert_memory_address (Pmode, x);
191 do_pending_stack_adjust ();
192 emit_indirect_jump (x);
195 /* Handle goto statements and the labels that they can go to. */
197 /* Specify the location in the RTL code of a label LABEL,
198 which is a LABEL_DECL tree node.
200 This is used for the kind of label that the user can jump to with a
201 goto statement, and for alternatives of a switch or case statement.
202 RTL labels generated for loops and conditionals don't go through here;
203 they are generated directly at the RTL level, by other functions below.
205 Note that this has nothing to do with defining label *names*.
206 Languages vary in how they do that and what that even means. */
209 expand_label (tree label)
211 rtx label_r = label_rtx (label);
213 do_pending_stack_adjust ();
214 emit_label (label_r);
215 if (DECL_NAME (label))
216 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
218 if (DECL_NONLOCAL (label))
220 expand_nl_goto_receiver ();
221 nonlocal_goto_handler_labels
222 = gen_rtx_EXPR_LIST (VOIDmode, label_r,
223 nonlocal_goto_handler_labels);
226 if (FORCED_LABEL (label))
227 forced_labels = gen_rtx_EXPR_LIST (VOIDmode, label_r, forced_labels);
229 if (DECL_NONLOCAL (label) || FORCED_LABEL (label))
230 maybe_set_first_label_num (label_r);
233 /* Generate RTL code for a `goto' statement with target label LABEL.
234 LABEL should be a LABEL_DECL tree node that was or will later be
235 defined with `expand_label'. */
238 expand_goto (tree label)
240 #ifdef ENABLE_CHECKING
241 /* Check for a nonlocal goto to a containing function. Should have
242 gotten translated to __builtin_nonlocal_goto. */
243 tree context = decl_function_context (label);
244 if (context != 0 && context != current_function_decl)
248 emit_jump (label_rtx (label));
251 /* Return the number of times character C occurs in string S. */
253 n_occurrences (int c, const char *s)
261 /* Generate RTL for an asm statement (explicit assembler code).
262 STRING is a STRING_CST node containing the assembler code text,
263 or an ADDR_EXPR containing a STRING_CST. VOL nonzero means the
264 insn is volatile; don't optimize it. */
267 expand_asm (tree string, int vol)
271 if (TREE_CODE (string) == ADDR_EXPR)
272 string = TREE_OPERAND (string, 0);
274 body = gen_rtx_ASM_INPUT (VOIDmode, TREE_STRING_POINTER (string));
276 MEM_VOLATILE_P (body) = vol;
281 /* Parse the output constraint pointed to by *CONSTRAINT_P. It is the
282 OPERAND_NUMth output operand, indexed from zero. There are NINPUTS
283 inputs and NOUTPUTS outputs to this extended-asm. Upon return,
284 *ALLOWS_MEM will be TRUE iff the constraint allows the use of a
285 memory operand. Similarly, *ALLOWS_REG will be TRUE iff the
286 constraint allows the use of a register operand. And, *IS_INOUT
287 will be true if the operand is read-write, i.e., if it is used as
288 an input as well as an output. If *CONSTRAINT_P is not in
289 canonical form, it will be made canonical. (Note that `+' will be
290 replaced with `=' as part of this process.)
292 Returns TRUE if all went well; FALSE if an error occurred. */
295 parse_output_constraint (const char **constraint_p, int operand_num,
296 int ninputs, int noutputs, bool *allows_mem,
297 bool *allows_reg, bool *is_inout)
299 const char *constraint = *constraint_p;
302 /* Assume the constraint doesn't allow the use of either a register
307 /* Allow the `=' or `+' to not be at the beginning of the string,
308 since it wasn't explicitly documented that way, and there is a
309 large body of code that puts it last. Swap the character to
310 the front, so as not to uglify any place else. */
311 p = strchr (constraint, '=');
313 p = strchr (constraint, '+');
315 /* If the string doesn't contain an `=', issue an error
319 error ("output operand constraint lacks `='");
323 /* If the constraint begins with `+', then the operand is both read
324 from and written to. */
325 *is_inout = (*p == '+');
327 /* Canonicalize the output constraint so that it begins with `='. */
328 if (p != constraint || is_inout)
331 size_t c_len = strlen (constraint);
334 warning ("output constraint `%c' for operand %d is not at the beginning",
337 /* Make a copy of the constraint. */
338 buf = alloca (c_len + 1);
339 strcpy (buf, constraint);
340 /* Swap the first character and the `=' or `+'. */
341 buf[p - constraint] = buf[0];
342 /* Make sure the first character is an `='. (Until we do this,
343 it might be a `+'.) */
345 /* Replace the constraint with the canonicalized string. */
346 *constraint_p = ggc_alloc_string (buf, c_len);
347 constraint = *constraint_p;
350 /* Loop through the constraint string. */
351 for (p = constraint + 1; *p; p += CONSTRAINT_LEN (*p, p))
356 error ("operand constraint contains incorrectly positioned '+' or '='");
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 `%c'", 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 `%c' 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 `%s' conflicts with asm clobber list",
612 IDENTIFIER_POINTER (DECL_NAME (decl)));
614 /* Reset registerness to stop multiple errors emitted for a
616 DECL_REGISTER (decl) = 0;
623 /* Generate RTL for an asm statement with arguments.
624 STRING is the instruction template.
625 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
626 Each output or input has an expression in the TREE_VALUE and
627 and a tree list in TREE_PURPOSE which in turn contains a constraint
628 name in TREE_VALUE (or NULL_TREE) and a constraint string
630 CLOBBERS is a list of STRING_CST nodes each naming a hard register
631 that is clobbered by this insn.
633 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
634 Some elements of OUTPUTS may be replaced with trees representing temporary
635 values. The caller should copy those temporary values to the originally
638 VOL nonzero means the insn is volatile; don't optimize it. */
641 expand_asm_operands (tree string, tree outputs, tree inputs,
642 tree clobbers, int vol, location_t locus)
644 rtvec argvec, constraintvec;
646 int ninputs = list_length (inputs);
647 int noutputs = list_length (outputs);
650 HARD_REG_SET clobbered_regs;
651 int clobber_conflict_found = 0;
655 /* Vector of RTX's of evaluated output operands. */
656 rtx *output_rtx = alloca (noutputs * sizeof (rtx));
657 int *inout_opnum = alloca (noutputs * sizeof (int));
658 rtx *real_output_rtx = alloca (noutputs * sizeof (rtx));
659 enum machine_mode *inout_mode
660 = alloca (noutputs * sizeof (enum machine_mode));
661 const char **constraints
662 = alloca ((noutputs + ninputs) * sizeof (const char *));
663 int old_generating_concat_p = generating_concat_p;
665 /* An ASM with no outputs needs to be treated as volatile, for now. */
669 if (! check_operand_nalternatives (outputs, inputs))
672 string = resolve_asm_operand_names (string, outputs, inputs);
674 /* Collect constraints. */
676 for (t = outputs; t ; t = TREE_CHAIN (t), i++)
677 constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
678 for (t = inputs; t ; t = TREE_CHAIN (t), i++)
679 constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
681 /* Sometimes we wish to automatically clobber registers across an asm.
682 Case in point is when the i386 backend moved from cc0 to a hard reg --
683 maintaining source-level compatibility means automatically clobbering
684 the flags register. */
685 clobbers = targetm.md_asm_clobbers (clobbers);
687 /* Count the number of meaningful clobbered registers, ignoring what
688 we would ignore later. */
690 CLEAR_HARD_REG_SET (clobbered_regs);
691 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
693 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
695 i = decode_reg_name (regname);
696 if (i >= 0 || i == -4)
699 error ("unknown register name `%s' in `asm'", regname);
701 /* Mark clobbered registers. */
704 /* Clobbering the PIC register is an error */
705 if (i == (int) PIC_OFFSET_TABLE_REGNUM)
707 error ("PIC register `%s' clobbered in `asm'", regname);
711 SET_HARD_REG_BIT (clobbered_regs, i);
715 /* First pass over inputs and outputs checks validity and sets
716 mark_addressable if needed. */
719 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
721 tree val = TREE_VALUE (tail);
722 tree type = TREE_TYPE (val);
723 const char *constraint;
728 /* If there's an erroneous arg, emit no insn. */
729 if (type == error_mark_node)
732 /* Try to parse the output constraint. If that fails, there's
733 no point in going further. */
734 constraint = constraints[i];
735 if (!parse_output_constraint (&constraint, i, ninputs, noutputs,
736 &allows_mem, &allows_reg, &is_inout))
743 && REG_P (DECL_RTL (val))
744 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type))))
745 lang_hooks.mark_addressable (val);
752 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
754 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
758 for (i = 0, tail = inputs; tail; i++, tail = TREE_CHAIN (tail))
760 bool allows_reg, allows_mem;
761 const char *constraint;
763 /* If there's an erroneous arg, emit no insn, because the ASM_INPUT
764 would get VOIDmode and that could cause a crash in reload. */
765 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
768 constraint = constraints[i + noutputs];
769 if (! parse_input_constraint (&constraint, i, ninputs, noutputs, ninout,
770 constraints, &allows_mem, &allows_reg))
773 if (! allows_reg && allows_mem)
774 lang_hooks.mark_addressable (TREE_VALUE (tail));
777 /* Second pass evaluates arguments. */
780 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
782 tree val = TREE_VALUE (tail);
783 tree type = TREE_TYPE (val);
789 if (!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;
870 constraint = constraints[i + noutputs];
871 if (! parse_input_constraint (&constraint, i, ninputs, noutputs, ninout,
872 constraints, &allows_mem, &allows_reg))
875 generating_concat_p = 0;
877 val = TREE_VALUE (tail);
878 type = TREE_TYPE (val);
879 op = expand_expr (val, NULL_RTX, VOIDmode,
880 (allows_mem && !allows_reg
881 ? EXPAND_MEMORY : EXPAND_NORMAL));
883 /* Never pass a CONCAT to an ASM. */
884 if (GET_CODE (op) == CONCAT)
885 op = force_reg (GET_MODE (op), op);
887 op = validize_mem (op);
889 if (asm_operand_ok (op, constraint) <= 0)
892 op = force_reg (TYPE_MODE (type), op);
893 else if (!allows_mem)
894 warning ("asm operand %d probably doesn't match constraints",
898 /* We won't recognize either volatile memory or memory
899 with a queued address as available a memory_operand
900 at this point. Ignore it: clearly this *is* a memory. */
904 warning ("use of memory input without lvalue in "
905 "asm operand %d is deprecated", i + noutputs);
909 rtx mem = force_const_mem (TYPE_MODE (type), op);
911 op = validize_mem (mem);
913 op = force_reg (TYPE_MODE (type), op);
916 || GET_CODE (op) == SUBREG
917 || GET_CODE (op) == CONCAT)
919 tree qual_type = build_qualified_type (type,
922 rtx memloc = assign_temp (qual_type, 1, 1, 1);
923 memloc = validize_mem (memloc);
924 emit_move_insn (memloc, op);
930 generating_concat_p = old_generating_concat_p;
931 ASM_OPERANDS_INPUT (body, i) = op;
933 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, i)
934 = gen_rtx_ASM_INPUT (TYPE_MODE (type), constraints[i + noutputs]);
936 if (decl_conflicts_with_clobbers_p (val, clobbered_regs))
937 clobber_conflict_found = 1;
940 /* Protect all the operands from the queue now that they have all been
943 generating_concat_p = 0;
945 /* For in-out operands, copy output rtx to input rtx. */
946 for (i = 0; i < ninout; i++)
948 int j = inout_opnum[i];
951 ASM_OPERANDS_INPUT (body, ninputs - ninout + i)
954 sprintf (buffer, "%d", j);
955 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, ninputs - ninout + i)
956 = gen_rtx_ASM_INPUT (inout_mode[i], ggc_strdup (buffer));
959 generating_concat_p = old_generating_concat_p;
961 /* Now, for each output, construct an rtx
962 (set OUTPUT (asm_operands INSN OUTPUTCONSTRAINT OUTPUTNUMBER
963 ARGVEC CONSTRAINTS OPNAMES))
964 If there is more than one, put them inside a PARALLEL. */
966 if (noutputs == 1 && nclobbers == 0)
968 ASM_OPERANDS_OUTPUT_CONSTRAINT (body) = constraints[0];
969 emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
972 else if (noutputs == 0 && nclobbers == 0)
974 /* No output operands: put in a raw ASM_OPERANDS rtx. */
986 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
988 /* For each output operand, store a SET. */
989 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
992 = gen_rtx_SET (VOIDmode,
995 (GET_MODE (output_rtx[i]),
996 TREE_STRING_POINTER (string),
997 constraints[i], i, argvec, constraintvec,
1000 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1003 /* If there are no outputs (but there are some clobbers)
1004 store the bare ASM_OPERANDS into the PARALLEL. */
1007 XVECEXP (body, 0, i++) = obody;
1009 /* Store (clobber REG) for each clobbered register specified. */
1011 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1013 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1014 int j = decode_reg_name (regname);
1019 if (j == -3) /* `cc', which is not a register */
1022 if (j == -4) /* `memory', don't cache memory across asm */
1024 XVECEXP (body, 0, i++)
1025 = gen_rtx_CLOBBER (VOIDmode,
1028 gen_rtx_SCRATCH (VOIDmode)));
1032 /* Ignore unknown register, error already signaled. */
1036 /* Use QImode since that's guaranteed to clobber just one reg. */
1037 clobbered_reg = gen_rtx_REG (QImode, j);
1039 /* Do sanity check for overlap between clobbers and respectively
1040 input and outputs that hasn't been handled. Such overlap
1041 should have been detected and reported above. */
1042 if (!clobber_conflict_found)
1046 /* We test the old body (obody) contents to avoid tripping
1047 over the under-construction body. */
1048 for (opno = 0; opno < noutputs; opno++)
1049 if (reg_overlap_mentioned_p (clobbered_reg, output_rtx[opno]))
1050 internal_error ("asm clobber conflict with output operand");
1052 for (opno = 0; opno < ninputs - ninout; opno++)
1053 if (reg_overlap_mentioned_p (clobbered_reg,
1054 ASM_OPERANDS_INPUT (obody, opno)))
1055 internal_error ("asm clobber conflict with input operand");
1058 XVECEXP (body, 0, i++)
1059 = gen_rtx_CLOBBER (VOIDmode, clobbered_reg);
1065 /* For any outputs that needed reloading into registers, spill them
1066 back to where they belong. */
1067 for (i = 0; i < noutputs; ++i)
1068 if (real_output_rtx[i])
1069 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1075 expand_asm_expr (tree exp)
1081 if (ASM_INPUT_P (exp))
1083 expand_asm (ASM_STRING (exp), ASM_VOLATILE_P (exp));
1087 outputs = ASM_OUTPUTS (exp);
1088 noutputs = list_length (outputs);
1089 /* o[I] is the place that output number I should be written. */
1090 o = (tree *) alloca (noutputs * sizeof (tree));
1092 /* Record the contents of OUTPUTS before it is modified. */
1093 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1094 o[i] = TREE_VALUE (tail);
1096 /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
1097 OUTPUTS some trees for where the values were actually stored. */
1098 expand_asm_operands (ASM_STRING (exp), outputs, ASM_INPUTS (exp),
1099 ASM_CLOBBERS (exp), ASM_VOLATILE_P (exp),
1102 /* Copy all the intermediate outputs into the specified outputs. */
1103 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1105 if (o[i] != TREE_VALUE (tail))
1107 expand_assignment (o[i], TREE_VALUE (tail), 0);
1110 /* Restore the original value so that it's correct the next
1111 time we expand this function. */
1112 TREE_VALUE (tail) = o[i];
1117 /* A subroutine of expand_asm_operands. Check that all operands have
1118 the same number of alternatives. Return true if so. */
1121 check_operand_nalternatives (tree outputs, tree inputs)
1123 if (outputs || inputs)
1125 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1127 = n_occurrences (',', TREE_STRING_POINTER (TREE_VALUE (tmp)));
1130 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1132 error ("too many alternatives in `asm'");
1139 const char *constraint
1140 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tmp)));
1142 if (n_occurrences (',', constraint) != nalternatives)
1144 error ("operand constraints for `asm' differ in number of alternatives");
1148 if (TREE_CHAIN (tmp))
1149 tmp = TREE_CHAIN (tmp);
1151 tmp = next, next = 0;
1158 /* A subroutine of expand_asm_operands. Check that all operand names
1159 are unique. Return true if so. We rely on the fact that these names
1160 are identifiers, and so have been canonicalized by get_identifier,
1161 so all we need are pointer comparisons. */
1164 check_unique_operand_names (tree outputs, tree inputs)
1168 for (i = outputs; i ; i = TREE_CHAIN (i))
1170 tree i_name = TREE_PURPOSE (TREE_PURPOSE (i));
1174 for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j))
1175 if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
1179 for (i = inputs; i ; i = TREE_CHAIN (i))
1181 tree i_name = TREE_PURPOSE (TREE_PURPOSE (i));
1185 for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j))
1186 if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
1188 for (j = outputs; j ; j = TREE_CHAIN (j))
1189 if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
1196 error ("duplicate asm operand name '%s'",
1197 TREE_STRING_POINTER (TREE_PURPOSE (TREE_PURPOSE (i))));
1201 /* A subroutine of expand_asm_operands. Resolve the names of the operands
1202 in *POUTPUTS and *PINPUTS to numbers, and replace the name expansions in
1203 STRING and in the constraints to those numbers. */
1206 resolve_asm_operand_names (tree string, tree outputs, tree inputs)
1213 check_unique_operand_names (outputs, inputs);
1215 /* Substitute [<name>] in input constraint strings. There should be no
1216 named operands in output constraints. */
1217 for (t = inputs; t ; t = TREE_CHAIN (t))
1219 c = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
1220 if (strchr (c, '[') != NULL)
1222 p = buffer = xstrdup (c);
1223 while ((p = strchr (p, '[')) != NULL)
1224 p = resolve_operand_name_1 (p, outputs, inputs);
1225 TREE_VALUE (TREE_PURPOSE (t))
1226 = build_string (strlen (buffer), buffer);
1231 /* Now check for any needed substitutions in the template. */
1232 c = TREE_STRING_POINTER (string);
1233 while ((c = strchr (c, '%')) != NULL)
1237 else if (ISALPHA (c[1]) && c[2] == '[')
1248 /* OK, we need to make a copy so we can perform the substitutions.
1249 Assume that we will not need extra space--we get to remove '['
1250 and ']', which means we cannot have a problem until we have more
1251 than 999 operands. */
1252 buffer = xstrdup (TREE_STRING_POINTER (string));
1253 p = buffer + (c - TREE_STRING_POINTER (string));
1255 while ((p = strchr (p, '%')) != NULL)
1259 else if (ISALPHA (p[1]) && p[2] == '[')
1267 p = resolve_operand_name_1 (p, outputs, inputs);
1270 string = build_string (strlen (buffer), buffer);
1277 /* A subroutine of resolve_operand_names. P points to the '[' for a
1278 potential named operand of the form [<name>]. In place, replace
1279 the name and brackets with a number. Return a pointer to the
1280 balance of the string after substitution. */
1283 resolve_operand_name_1 (char *p, tree outputs, tree inputs)
1290 /* Collect the operand name. */
1291 q = strchr (p, ']');
1294 error ("missing close brace for named operand");
1295 return strchr (p, '\0');
1299 /* Resolve the name to a number. */
1300 for (op = 0, t = outputs; t ; t = TREE_CHAIN (t), op++)
1302 tree name = TREE_PURPOSE (TREE_PURPOSE (t));
1305 const char *c = TREE_STRING_POINTER (name);
1306 if (strncmp (c, p + 1, len) == 0 && c[len] == '\0')
1310 for (t = inputs; t ; t = TREE_CHAIN (t), op++)
1312 tree name = TREE_PURPOSE (TREE_PURPOSE (t));
1315 const char *c = TREE_STRING_POINTER (name);
1316 if (strncmp (c, p + 1, len) == 0 && c[len] == '\0')
1322 error ("undefined named operand '%s'", p + 1);
1326 /* Replace the name with the number. Unfortunately, not all libraries
1327 get the return value of sprintf correct, so search for the end of the
1328 generated string by hand. */
1329 sprintf (p, "%d", op);
1330 p = strchr (p, '\0');
1332 /* Verify the no extra buffer space assumption. */
1336 /* Shift the rest of the buffer down to fill the gap. */
1337 memmove (p, q + 1, strlen (q + 1) + 1);
1342 /* Generate RTL to evaluate the expression EXP. */
1345 expand_expr_stmt (tree exp)
1350 value = expand_expr (exp, const0_rtx, VOIDmode, 0);
1351 type = TREE_TYPE (exp);
1353 /* If all we do is reference a volatile value in memory,
1354 copy it to a register to be sure it is actually touched. */
1355 if (value && MEM_P (value) && TREE_THIS_VOLATILE (exp))
1357 if (TYPE_MODE (type) == VOIDmode)
1359 else if (TYPE_MODE (type) != BLKmode)
1360 value = copy_to_reg (value);
1363 rtx lab = gen_label_rtx ();
1365 /* Compare the value with itself to reference it. */
1366 emit_cmp_and_jump_insns (value, value, EQ,
1367 expand_expr (TYPE_SIZE (type),
1368 NULL_RTX, VOIDmode, 0),
1374 /* Free any temporaries used to evaluate this expression. */
1378 /* Warn if EXP contains any computations whose results are not used.
1379 Return 1 if a warning is printed; 0 otherwise. LOCUS is the
1380 (potential) location of the expression. */
1383 warn_if_unused_value (tree exp, location_t locus)
1386 if (TREE_USED (exp))
1389 /* Don't warn about void constructs. This includes casting to void,
1390 void function calls, and statement expressions with a final cast
1392 if (VOID_TYPE_P (TREE_TYPE (exp)))
1395 if (EXPR_HAS_LOCATION (exp))
1396 locus = EXPR_LOCATION (exp);
1398 switch (TREE_CODE (exp))
1400 case PREINCREMENT_EXPR:
1401 case POSTINCREMENT_EXPR:
1402 case PREDECREMENT_EXPR:
1403 case POSTDECREMENT_EXPR:
1408 case TRY_CATCH_EXPR:
1409 case WITH_CLEANUP_EXPR:
1414 /* For a binding, warn if no side effect within it. */
1415 exp = BIND_EXPR_BODY (exp);
1419 exp = TREE_OPERAND (exp, 0);
1422 case TRUTH_ORIF_EXPR:
1423 case TRUTH_ANDIF_EXPR:
1424 /* In && or ||, warn if 2nd operand has no side effect. */
1425 exp = TREE_OPERAND (exp, 1);
1429 if (TREE_NO_WARNING (exp))
1431 if (warn_if_unused_value (TREE_OPERAND (exp, 0), locus))
1433 /* Let people do `(foo (), 0)' without a warning. */
1434 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1436 exp = TREE_OPERAND (exp, 1);
1441 case NON_LVALUE_EXPR:
1442 /* Don't warn about conversions not explicit in the user's program. */
1443 if (TREE_NO_WARNING (exp))
1445 /* Assignment to a cast usually results in a cast of a modify.
1446 Don't complain about that. There can be an arbitrary number of
1447 casts before the modify, so we must loop until we find the first
1448 non-cast expression and then test to see if that is a modify. */
1450 tree tem = TREE_OPERAND (exp, 0);
1452 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1453 tem = TREE_OPERAND (tem, 0);
1455 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1456 || TREE_CODE (tem) == CALL_EXPR)
1462 /* Don't warn about automatic dereferencing of references, since
1463 the user cannot control it. */
1464 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1466 exp = TREE_OPERAND (exp, 0);
1472 /* Referencing a volatile value is a side effect, so don't warn. */
1474 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
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 (TREE_CODE_CLASS (TREE_CODE (exp)) == 'e'
1482 && TREE_CODE_LENGTH (TREE_CODE (exp)) == 0)
1486 /* If this is an expression with side effects, don't warn. */
1487 if (TREE_SIDE_EFFECTS (exp))
1490 warning ("%Hvalue computed is not used", &locus);
1495 /* Return nonzero if we should preserve sub-expressions as separate
1496 pseudos. We never do so if we aren't optimizing. We always do so
1497 if -fexpensive-optimizations. */
1500 preserve_subexpressions_p (void)
1502 return optimize && (cfun || flag_expensive_optimizations);
1506 /* Generate RTL to return from the current function, with no value.
1507 (That is, we do not do anything about returning any value.) */
1510 expand_null_return (void)
1512 /* If this function was declared to return a value, but we
1513 didn't, clobber the return registers so that they are not
1514 propagated live to the rest of the function. */
1515 clobber_return_register ();
1517 expand_null_return_1 ();
1520 /* Generate RTL to return directly from the current function.
1521 (That is, we bypass any return value.) */
1524 expand_naked_return (void)
1528 clear_pending_stack_adjust ();
1529 do_pending_stack_adjust ();
1531 end_label = naked_return_label;
1533 end_label = naked_return_label = gen_label_rtx ();
1535 emit_jump (end_label);
1538 /* If the current function returns values in the most significant part
1539 of a register, shift return value VAL appropriately. The mode of
1540 the function's return type is known not to be BLKmode. */
1543 shift_return_value (rtx val)
1547 type = TREE_TYPE (DECL_RESULT (current_function_decl));
1548 if (targetm.calls.return_in_msb (type))
1551 HOST_WIDE_INT shift;
1553 target = DECL_RTL (DECL_RESULT (current_function_decl));
1554 shift = (GET_MODE_BITSIZE (GET_MODE (target))
1555 - BITS_PER_UNIT * int_size_in_bytes (type));
1557 val = expand_shift (LSHIFT_EXPR, GET_MODE (target),
1558 gen_lowpart (GET_MODE (target), val),
1559 build_int_2 (shift, 0), target, 1);
1565 /* Generate RTL to return from the current function, with value VAL. */
1568 expand_value_return (rtx val)
1570 /* Copy the value to the return location
1571 unless it's already there. */
1573 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
1574 if (return_reg != val)
1576 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
1577 if (targetm.calls.promote_function_return (TREE_TYPE (current_function_decl)))
1579 int unsignedp = TYPE_UNSIGNED (type);
1580 enum machine_mode old_mode
1581 = DECL_MODE (DECL_RESULT (current_function_decl));
1582 enum machine_mode mode
1583 = promote_mode (type, old_mode, &unsignedp, 1);
1585 if (mode != old_mode)
1586 val = convert_modes (mode, old_mode, val, unsignedp);
1588 if (GET_CODE (return_reg) == PARALLEL)
1589 emit_group_load (return_reg, val, type, int_size_in_bytes (type));
1591 emit_move_insn (return_reg, val);
1594 expand_null_return_1 ();
1597 /* Output a return with no value. */
1600 expand_null_return_1 (void)
1604 clear_pending_stack_adjust ();
1605 do_pending_stack_adjust ();
1607 end_label = return_label;
1609 end_label = return_label = gen_label_rtx ();
1610 emit_jump (end_label);
1613 /* Generate RTL to evaluate the expression RETVAL and return it
1614 from the current function. */
1617 expand_return (tree retval)
1623 /* If function wants no value, give it none. */
1624 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
1626 expand_expr (retval, NULL_RTX, VOIDmode, 0);
1627 expand_null_return ();
1631 if (retval == error_mark_node)
1633 /* Treat this like a return of no value from a function that
1635 expand_null_return ();
1638 else if (TREE_CODE (retval) == RESULT_DECL)
1639 retval_rhs = retval;
1640 else if ((TREE_CODE (retval) == MODIFY_EXPR
1641 || TREE_CODE (retval) == INIT_EXPR)
1642 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
1643 retval_rhs = TREE_OPERAND (retval, 1);
1645 retval_rhs = retval;
1647 result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
1649 /* If the result is an aggregate that is being returned in one (or more)
1650 registers, load the registers here. The compiler currently can't handle
1651 copying a BLKmode value into registers. We could put this code in a
1652 more general area (for use by everyone instead of just function
1653 call/return), but until this feature is generally usable it is kept here
1654 (and in expand_call). */
1657 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
1658 && REG_P (result_rtl))
1661 unsigned HOST_WIDE_INT bitpos, xbitpos;
1662 unsigned HOST_WIDE_INT padding_correction = 0;
1663 unsigned HOST_WIDE_INT bytes
1664 = int_size_in_bytes (TREE_TYPE (retval_rhs));
1665 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
1666 unsigned int bitsize
1667 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), BITS_PER_WORD);
1668 rtx *result_pseudos = alloca (sizeof (rtx) * n_regs);
1669 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
1670 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
1671 enum machine_mode tmpmode, result_reg_mode;
1675 expand_null_return ();
1679 /* If the structure doesn't take up a whole number of words, see
1680 whether the register value should be padded on the left or on
1681 the right. Set PADDING_CORRECTION to the number of padding
1682 bits needed on the left side.
1684 In most ABIs, the structure will be returned at the least end of
1685 the register, which translates to right padding on little-endian
1686 targets and left padding on big-endian targets. The opposite
1687 holds if the structure is returned at the most significant
1688 end of the register. */
1689 if (bytes % UNITS_PER_WORD != 0
1690 && (targetm.calls.return_in_msb (TREE_TYPE (retval_rhs))
1692 : BYTES_BIG_ENDIAN))
1693 padding_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
1696 /* Copy the structure BITSIZE bits at a time. */
1697 for (bitpos = 0, xbitpos = padding_correction;
1698 bitpos < bytes * BITS_PER_UNIT;
1699 bitpos += bitsize, xbitpos += bitsize)
1701 /* We need a new destination pseudo each time xbitpos is
1702 on a word boundary and when xbitpos == padding_correction
1703 (the first time through). */
1704 if (xbitpos % BITS_PER_WORD == 0
1705 || xbitpos == padding_correction)
1707 /* Generate an appropriate register. */
1708 dst = gen_reg_rtx (word_mode);
1709 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
1711 /* Clear the destination before we move anything into it. */
1712 emit_move_insn (dst, CONST0_RTX (GET_MODE (dst)));
1715 /* We need a new source operand each time bitpos is on a word
1717 if (bitpos % BITS_PER_WORD == 0)
1718 src = operand_subword_force (result_val,
1719 bitpos / BITS_PER_WORD,
1722 /* Use bitpos for the source extraction (left justified) and
1723 xbitpos for the destination store (right justified). */
1724 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
1725 extract_bit_field (src, bitsize,
1726 bitpos % BITS_PER_WORD, 1,
1727 NULL_RTX, word_mode, word_mode));
1730 tmpmode = GET_MODE (result_rtl);
1731 if (tmpmode == BLKmode)
1733 /* Find the smallest integer mode large enough to hold the
1734 entire structure and use that mode instead of BLKmode
1735 on the USE insn for the return register. */
1736 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
1737 tmpmode != VOIDmode;
1738 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
1739 /* Have we found a large enough mode? */
1740 if (GET_MODE_SIZE (tmpmode) >= bytes)
1743 /* No suitable mode found. */
1744 if (tmpmode == VOIDmode)
1747 PUT_MODE (result_rtl, tmpmode);
1750 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
1751 result_reg_mode = word_mode;
1753 result_reg_mode = tmpmode;
1754 result_reg = gen_reg_rtx (result_reg_mode);
1756 for (i = 0; i < n_regs; i++)
1757 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
1760 if (tmpmode != result_reg_mode)
1761 result_reg = gen_lowpart (tmpmode, result_reg);
1763 expand_value_return (result_reg);
1765 else if (retval_rhs != 0
1766 && !VOID_TYPE_P (TREE_TYPE (retval_rhs))
1767 && (REG_P (result_rtl)
1768 || (GET_CODE (result_rtl) == PARALLEL)))
1770 /* Calculate the return value into a temporary (usually a pseudo
1772 tree ot = TREE_TYPE (DECL_RESULT (current_function_decl));
1773 tree nt = build_qualified_type (ot, TYPE_QUALS (ot) | TYPE_QUAL_CONST);
1775 val = assign_temp (nt, 0, 0, 1);
1776 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
1777 val = force_not_mem (val);
1778 /* Return the calculated value. */
1779 expand_value_return (shift_return_value (val));
1783 /* No hard reg used; calculate value into hard return reg. */
1784 expand_expr (retval, const0_rtx, VOIDmode, 0);
1785 expand_value_return (result_rtl);
1789 /* Given a pointer to a BLOCK node return nonzero if (and only if) the node
1790 in question represents the outermost pair of curly braces (i.e. the "body
1791 block") of a function or method.
1793 For any BLOCK node representing a "body block" of a function or method, the
1794 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
1795 represents the outermost (function) scope for the function or method (i.e.
1796 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
1797 *that* node in turn will point to the relevant FUNCTION_DECL node. */
1800 is_body_block (tree stmt)
1802 if (lang_hooks.no_body_blocks)
1805 if (TREE_CODE (stmt) == BLOCK)
1807 tree parent = BLOCK_SUPERCONTEXT (stmt);
1809 if (parent && TREE_CODE (parent) == BLOCK)
1811 tree grandparent = BLOCK_SUPERCONTEXT (parent);
1813 if (grandparent && TREE_CODE (grandparent) == FUNCTION_DECL)
1821 /* Emit code to restore vital registers at the beginning of a nonlocal goto
1824 expand_nl_goto_receiver (void)
1826 /* Clobber the FP when we get here, so we have to make sure it's
1827 marked as used by this function. */
1828 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
1830 /* Mark the static chain as clobbered here so life information
1831 doesn't get messed up for it. */
1832 emit_insn (gen_rtx_CLOBBER (VOIDmode, static_chain_rtx));
1834 #ifdef HAVE_nonlocal_goto
1835 if (! HAVE_nonlocal_goto)
1837 /* First adjust our frame pointer to its actual value. It was
1838 previously set to the start of the virtual area corresponding to
1839 the stacked variables when we branched here and now needs to be
1840 adjusted to the actual hardware fp value.
1842 Assignments are to virtual registers are converted by
1843 instantiate_virtual_regs into the corresponding assignment
1844 to the underlying register (fp in this case) that makes
1845 the original assignment true.
1846 So the following insn will actually be
1847 decrementing fp by STARTING_FRAME_OFFSET. */
1848 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
1850 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
1851 if (fixed_regs[ARG_POINTER_REGNUM])
1853 #ifdef ELIMINABLE_REGS
1854 /* If the argument pointer can be eliminated in favor of the
1855 frame pointer, we don't need to restore it. We assume here
1856 that if such an elimination is present, it can always be used.
1857 This is the case on all known machines; if we don't make this
1858 assumption, we do unnecessary saving on many machines. */
1859 static const struct elims {const int from, to;} elim_regs[] = ELIMINABLE_REGS;
1862 for (i = 0; i < ARRAY_SIZE (elim_regs); i++)
1863 if (elim_regs[i].from == ARG_POINTER_REGNUM
1864 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
1867 if (i == ARRAY_SIZE (elim_regs))
1870 /* Now restore our arg pointer from the address at which it
1871 was saved in our stack frame. */
1872 emit_move_insn (virtual_incoming_args_rtx,
1873 copy_to_reg (get_arg_pointer_save_area (cfun)));
1878 #ifdef HAVE_nonlocal_goto_receiver
1879 if (HAVE_nonlocal_goto_receiver)
1880 emit_insn (gen_nonlocal_goto_receiver ());
1883 /* @@@ This is a kludge. Not all machine descriptions define a blockage
1884 insn, but we must not allow the code we just generated to be reordered
1885 by scheduling. Specifically, the update of the frame pointer must
1886 happen immediately, not later. So emit an ASM_INPUT to act as blockage
1888 emit_insn (gen_rtx_ASM_INPUT (VOIDmode, ""));
1891 /* Generate RTL for the automatic variable declaration DECL.
1892 (Other kinds of declarations are simply ignored if seen here.) */
1895 expand_decl (tree decl)
1899 type = TREE_TYPE (decl);
1901 /* For a CONST_DECL, set mode, alignment, and sizes from those of the
1902 type in case this node is used in a reference. */
1903 if (TREE_CODE (decl) == CONST_DECL)
1905 DECL_MODE (decl) = TYPE_MODE (type);
1906 DECL_ALIGN (decl) = TYPE_ALIGN (type);
1907 DECL_SIZE (decl) = TYPE_SIZE (type);
1908 DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (type);
1912 /* Otherwise, only automatic variables need any expansion done. Static and
1913 external variables, and external functions, will be handled by
1914 `assemble_variable' (called from finish_decl). TYPE_DECL requires
1915 nothing. PARM_DECLs are handled in `assign_parms'. */
1916 if (TREE_CODE (decl) != VAR_DECL)
1919 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
1922 /* Create the RTL representation for the variable. */
1924 if (type == error_mark_node)
1925 SET_DECL_RTL (decl, gen_rtx_MEM (BLKmode, const0_rtx));
1927 else if (DECL_SIZE (decl) == 0)
1928 /* Variable with incomplete type. */
1931 if (DECL_INITIAL (decl) == 0)
1932 /* Error message was already done; now avoid a crash. */
1933 x = gen_rtx_MEM (BLKmode, const0_rtx);
1935 /* An initializer is going to decide the size of this array.
1936 Until we know the size, represent its address with a reg. */
1937 x = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
1939 set_mem_attributes (x, decl, 1);
1940 SET_DECL_RTL (decl, x);
1942 else if (use_register_for_decl (decl))
1944 /* Automatic variable that can go in a register. */
1945 int unsignedp = TYPE_UNSIGNED (type);
1946 enum machine_mode reg_mode
1947 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
1949 SET_DECL_RTL (decl, gen_reg_rtx (reg_mode));
1951 /* Note if the object is a user variable. */
1952 if (!DECL_ARTIFICIAL (decl))
1954 mark_user_reg (DECL_RTL (decl));
1956 /* Trust user variables which have a pointer type to really
1957 be pointers. Do not trust compiler generated temporaries
1958 as our type system is totally busted as it relates to
1959 pointer arithmetic which translates into lots of compiler
1960 generated objects with pointer types, but which are not really
1962 if (POINTER_TYPE_P (type))
1963 mark_reg_pointer (DECL_RTL (decl),
1964 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
1967 maybe_set_unchanging (DECL_RTL (decl), decl);
1970 else if (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST
1971 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
1972 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl),
1973 STACK_CHECK_MAX_VAR_SIZE)))
1975 /* Variable of fixed size that goes on the stack. */
1980 /* If we previously made RTL for this decl, it must be an array
1981 whose size was determined by the initializer.
1982 The old address was a register; set that register now
1983 to the proper address. */
1984 if (DECL_RTL_SET_P (decl))
1986 if (!MEM_P (DECL_RTL (decl))
1987 || !REG_P (XEXP (DECL_RTL (decl), 0)))
1989 oldaddr = XEXP (DECL_RTL (decl), 0);
1992 /* Set alignment we actually gave this decl. */
1993 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
1994 : GET_MODE_BITSIZE (DECL_MODE (decl)));
1995 DECL_USER_ALIGN (decl) = 0;
1997 x = assign_temp (decl, 1, 1, 1);
1998 set_mem_attributes (x, decl, 1);
1999 SET_DECL_RTL (decl, x);
2003 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
2004 if (addr != oldaddr)
2005 emit_move_insn (oldaddr, addr);
2009 /* Dynamic-size object: must push space on the stack. */
2011 rtx address, size, x;
2013 /* Record the stack pointer on entry to block, if have
2014 not already done so. */
2015 do_pending_stack_adjust ();
2017 /* Compute the variable's size, in bytes. This will expand any
2018 needed SAVE_EXPRs for the first time. */
2019 size = expand_expr (DECL_SIZE_UNIT (decl), NULL_RTX, VOIDmode, 0);
2022 /* Allocate space on the stack for the variable. Note that
2023 DECL_ALIGN says how the variable is to be aligned and we
2024 cannot use it to conclude anything about the alignment of
2026 address = allocate_dynamic_stack_space (size, NULL_RTX,
2027 TYPE_ALIGN (TREE_TYPE (decl)));
2029 /* Reference the variable indirect through that rtx. */
2030 x = gen_rtx_MEM (DECL_MODE (decl), address);
2031 set_mem_attributes (x, decl, 1);
2032 SET_DECL_RTL (decl, x);
2035 /* Indicate the alignment we actually gave this variable. */
2036 #ifdef STACK_BOUNDARY
2037 DECL_ALIGN (decl) = STACK_BOUNDARY;
2039 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
2041 DECL_USER_ALIGN (decl) = 0;
2045 /* Emit code to allocate T_SIZE bytes of dynamic stack space for ALLOC. */
2047 expand_stack_alloc (tree alloc, tree t_size)
2049 rtx address, dest, size;
2052 if (TREE_CODE (alloc) != ADDR_EXPR)
2054 var = TREE_OPERAND (alloc, 0);
2055 if (TREE_CODE (var) != VAR_DECL)
2058 type = TREE_TYPE (var);
2060 /* Compute the variable's size, in bytes. */
2061 size = expand_expr (t_size, NULL_RTX, VOIDmode, 0);
2064 /* Allocate space on the stack for the variable. */
2065 address = XEXP (DECL_RTL (var), 0);
2066 dest = allocate_dynamic_stack_space (size, address, TYPE_ALIGN (type));
2067 if (dest != address)
2068 emit_move_insn (address, dest);
2070 /* Indicate the alignment we actually gave this variable. */
2071 #ifdef STACK_BOUNDARY
2072 DECL_ALIGN (var) = STACK_BOUNDARY;
2074 DECL_ALIGN (var) = BIGGEST_ALIGNMENT;
2076 DECL_USER_ALIGN (var) = 0;
2079 /* Emit code to save the current value of stack. */
2081 expand_stack_save (void)
2085 do_pending_stack_adjust ();
2086 emit_stack_save (SAVE_BLOCK, &ret, NULL_RTX);
2090 /* Emit code to restore the current value of stack. */
2092 expand_stack_restore (tree var)
2094 rtx sa = DECL_RTL (var);
2096 emit_stack_restore (SAVE_BLOCK, sa, NULL_RTX);
2099 /* Emit code to perform the initialization of a declaration DECL. */
2102 expand_decl_init (tree decl)
2104 int was_used = TREE_USED (decl);
2106 /* If this is a CONST_DECL, we don't have to generate any code. Likewise
2107 for static decls. */
2108 if (TREE_CODE (decl) == CONST_DECL
2109 || TREE_STATIC (decl))
2112 /* Compute and store the initial value now. */
2116 if (DECL_INITIAL (decl) == error_mark_node)
2118 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
2120 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
2121 || code == POINTER_TYPE || code == REFERENCE_TYPE)
2122 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
2125 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
2127 emit_line_note (DECL_SOURCE_LOCATION (decl));
2128 expand_assignment (decl, DECL_INITIAL (decl), 0);
2131 /* Don't let the initialization count as "using" the variable. */
2132 TREE_USED (decl) = was_used;
2134 /* Free any temporaries we made while initializing the decl. */
2135 preserve_temp_slots (NULL_RTX);
2141 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
2142 DECL_ELTS is the list of elements that belong to DECL's type.
2143 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
2146 expand_anon_union_decl (tree decl, tree cleanup ATTRIBUTE_UNUSED,
2152 /* If any of the elements are addressable, so is the entire union. */
2153 for (t = decl_elts; t; t = TREE_CHAIN (t))
2154 if (TREE_ADDRESSABLE (TREE_VALUE (t)))
2156 TREE_ADDRESSABLE (decl) = 1;
2161 x = DECL_RTL (decl);
2163 /* Go through the elements, assigning RTL to each. */
2164 for (t = decl_elts; t; t = TREE_CHAIN (t))
2166 tree decl_elt = TREE_VALUE (t);
2167 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
2169 /* If any of the elements are addressable, so is the entire
2171 if (TREE_USED (decl_elt))
2172 TREE_USED (decl) = 1;
2174 /* Propagate the union's alignment to the elements. */
2175 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
2176 DECL_USER_ALIGN (decl_elt) = DECL_USER_ALIGN (decl);
2178 /* If the element has BLKmode and the union doesn't, the union is
2179 aligned such that the element doesn't need to have BLKmode, so
2180 change the element's mode to the appropriate one for its size. */
2181 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
2182 DECL_MODE (decl_elt) = mode
2183 = mode_for_size_tree (DECL_SIZE (decl_elt), MODE_INT, 1);
2185 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
2186 instead create a new MEM rtx with the proper mode. */
2189 if (mode == GET_MODE (x))
2190 SET_DECL_RTL (decl_elt, x);
2192 SET_DECL_RTL (decl_elt, adjust_address_nv (x, mode, 0));
2196 if (mode == GET_MODE (x))
2197 SET_DECL_RTL (decl_elt, x);
2199 SET_DECL_RTL (decl_elt, gen_lowpart_SUBREG (mode, x));
2206 /* Do the insertion of a case label into case_list. The labels are
2207 fed to us in descending order from the sorted vector of case labels used
2208 in the tree part of the middle end. So the list we construct is
2209 sorted in ascending order. */
2212 add_case_node (struct case_node *head, tree low, tree high, tree label)
2214 struct case_node *r;
2216 /* If there's no HIGH value, then this is not a case range; it's
2217 just a simple case label. But that's just a degenerate case
2219 If the bounds are equal, turn this into the one-value case. */
2220 if (!high || tree_int_cst_equal (low, high))
2223 /* Add this label to the chain. */
2224 r = ggc_alloc (sizeof (struct case_node));
2227 r->code_label = label;
2228 r->parent = r->left = NULL;
2233 /* Maximum number of case bit tests. */
2234 #define MAX_CASE_BIT_TESTS 3
2236 /* By default, enable case bit tests on targets with ashlsi3. */
2237 #ifndef CASE_USE_BIT_TESTS
2238 #define CASE_USE_BIT_TESTS (ashl_optab->handlers[word_mode].insn_code \
2239 != CODE_FOR_nothing)
2243 /* A case_bit_test represents a set of case nodes that may be
2244 selected from using a bit-wise comparison. HI and LO hold
2245 the integer to be tested against, LABEL contains the label
2246 to jump to upon success and BITS counts the number of case
2247 nodes handled by this test, typically the number of bits
2250 struct case_bit_test
2258 /* Determine whether "1 << x" is relatively cheap in word_mode. */
2261 bool lshift_cheap_p (void)
2263 static bool init = false;
2264 static bool cheap = true;
2268 rtx reg = gen_rtx_REG (word_mode, 10000);
2269 int cost = rtx_cost (gen_rtx_ASHIFT (word_mode, const1_rtx, reg), SET);
2270 cheap = cost < COSTS_N_INSNS (3);
2277 /* Comparison function for qsort to order bit tests by decreasing
2278 number of case nodes, i.e. the node with the most cases gets
2282 case_bit_test_cmp (const void *p1, const void *p2)
2284 const struct case_bit_test *d1 = p1;
2285 const struct case_bit_test *d2 = p2;
2287 return d2->bits - d1->bits;
2290 /* Expand a switch statement by a short sequence of bit-wise
2291 comparisons. "switch(x)" is effectively converted into
2292 "if ((1 << (x-MINVAL)) & CST)" where CST and MINVAL are
2295 INDEX_EXPR is the value being switched on, which is of
2296 type INDEX_TYPE. MINVAL is the lowest case value of in
2297 the case nodes, of INDEX_TYPE type, and RANGE is highest
2298 value minus MINVAL, also of type INDEX_TYPE. NODES is
2299 the set of case nodes, and DEFAULT_LABEL is the label to
2300 branch to should none of the cases match.
2302 There *MUST* be MAX_CASE_BIT_TESTS or less unique case
2306 emit_case_bit_tests (tree index_type, tree index_expr, tree minval,
2307 tree range, case_node_ptr nodes, rtx default_label)
2309 struct case_bit_test test[MAX_CASE_BIT_TESTS];
2310 enum machine_mode mode;
2311 rtx expr, index, label;
2312 unsigned int i,j,lo,hi;
2313 struct case_node *n;
2317 for (n = nodes; n; n = n->right)
2319 label = label_rtx (n->code_label);
2320 for (i = 0; i < count; i++)
2321 if (label == test[i].label)
2326 if (count >= MAX_CASE_BIT_TESTS)
2330 test[i].label = label;
2337 lo = tree_low_cst (fold (build2 (MINUS_EXPR, index_type,
2338 n->low, minval)), 1);
2339 hi = tree_low_cst (fold (build2 (MINUS_EXPR, index_type,
2340 n->high, minval)), 1);
2341 for (j = lo; j <= hi; j++)
2342 if (j >= HOST_BITS_PER_WIDE_INT)
2343 test[i].hi |= (HOST_WIDE_INT) 1 << (j - HOST_BITS_PER_INT);
2345 test[i].lo |= (HOST_WIDE_INT) 1 << j;
2348 qsort (test, count, sizeof(*test), case_bit_test_cmp);
2350 index_expr = fold (build2 (MINUS_EXPR, index_type,
2351 convert (index_type, index_expr),
2352 convert (index_type, minval)));
2353 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
2354 do_pending_stack_adjust ();
2356 mode = TYPE_MODE (index_type);
2357 expr = expand_expr (range, NULL_RTX, VOIDmode, 0);
2358 emit_cmp_and_jump_insns (index, expr, GTU, NULL_RTX, mode, 1,
2361 index = convert_to_mode (word_mode, index, 0);
2362 index = expand_binop (word_mode, ashl_optab, const1_rtx,
2363 index, NULL_RTX, 1, OPTAB_WIDEN);
2365 for (i = 0; i < count; i++)
2367 expr = immed_double_const (test[i].lo, test[i].hi, word_mode);
2368 expr = expand_binop (word_mode, and_optab, index, expr,
2369 NULL_RTX, 1, OPTAB_WIDEN);
2370 emit_cmp_and_jump_insns (expr, const0_rtx, NE, NULL_RTX,
2371 word_mode, 1, test[i].label);
2374 emit_jump (default_label);
2378 #define HAVE_casesi 0
2381 #ifndef HAVE_tablejump
2382 #define HAVE_tablejump 0
2385 /* Terminate a case (Pascal) or switch (C) statement
2386 in which ORIG_INDEX is the expression to be tested.
2387 If ORIG_TYPE is not NULL, it is the original ORIG_INDEX
2388 type as given in the source before any compiler conversions.
2389 Generate the code to test it and jump to the right place. */
2392 expand_case (tree exp)
2394 tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE;
2395 rtx default_label = 0;
2396 struct case_node *n, *m;
2397 unsigned int count, uniq;
2403 rtx before_case, end, lab;
2405 tree vec = SWITCH_LABELS (exp);
2406 tree orig_type = TREE_TYPE (exp);
2407 tree index_expr = SWITCH_COND (exp);
2408 tree index_type = TREE_TYPE (index_expr);
2409 int unsignedp = TYPE_UNSIGNED (index_type);
2411 /* The insn after which the case dispatch should finally
2412 be emitted. Zero for a dummy. */
2415 /* A list of case labels; it is first built as a list and it may then
2416 be rearranged into a nearly balanced binary tree. */
2417 struct case_node *case_list = 0;
2419 /* Label to jump to if no case matches. */
2420 tree default_label_decl = 0;
2422 /* The switch body is lowered in gimplify.c, we should never have
2423 switches with a non-NULL SWITCH_BODY here. */
2424 if (SWITCH_BODY (exp) || !SWITCH_LABELS (exp))
2427 for (i = TREE_VEC_LENGTH (vec); --i >= 0; )
2429 tree elt = TREE_VEC_ELT (vec, i);
2431 /* Handle default labels specially. */
2432 if (!CASE_HIGH (elt) && !CASE_LOW (elt))
2434 #ifdef ENABLE_CHECKING
2435 if (default_label_decl != 0)
2438 default_label_decl = CASE_LABEL (elt);
2441 case_list = add_case_node (case_list, CASE_LOW (elt), CASE_HIGH (elt),
2445 do_pending_stack_adjust ();
2447 /* Make sure start points to something that won't need any transformation
2448 before the end of this function. */
2449 if (!NOTE_P (get_last_insn ()))
2450 emit_note (NOTE_INSN_DELETED);
2452 start = get_last_insn ();
2454 /* An ERROR_MARK occurs for various reasons including invalid data type. */
2455 if (index_type != error_mark_node)
2457 /* If we don't have a default-label, create one here,
2458 after the body of the switch. */
2459 if (default_label_decl == 0)
2462 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
2463 expand_label (default_label_decl);
2465 default_label = label_rtx (default_label_decl);
2467 before_case = get_last_insn ();
2469 /* Get upper and lower bounds of case values.
2470 Also convert all the case values to the index expr's data type. */
2474 for (n = case_list; n; n = n->right)
2476 /* Check low and high label values are integers. */
2477 if (TREE_CODE (n->low) != INTEGER_CST)
2479 if (TREE_CODE (n->high) != INTEGER_CST)
2482 n->low = convert (index_type, n->low);
2483 n->high = convert (index_type, n->high);
2485 /* Count the elements and track the largest and smallest
2486 of them (treating them as signed even if they are not). */
2494 if (INT_CST_LT (n->low, minval))
2496 if (INT_CST_LT (maxval, n->high))
2499 /* A range counts double, since it requires two compares. */
2500 if (! tree_int_cst_equal (n->low, n->high))
2503 /* Count the number of unique case node targets. */
2505 lab = label_rtx (n->code_label);
2506 for (m = case_list; m != n; m = m->right)
2507 if (label_rtx (m->code_label) == lab)
2514 /* Compute span of values. */
2516 range = fold (build2 (MINUS_EXPR, index_type, maxval, minval));
2520 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
2521 emit_jump (default_label);
2524 /* Try implementing this switch statement by a short sequence of
2525 bit-wise comparisons. However, we let the binary-tree case
2526 below handle constant index expressions. */
2527 else if (CASE_USE_BIT_TESTS
2528 && ! TREE_CONSTANT (index_expr)
2529 && compare_tree_int (range, GET_MODE_BITSIZE (word_mode)) < 0
2530 && compare_tree_int (range, 0) > 0
2531 && lshift_cheap_p ()
2532 && ((uniq == 1 && count >= 3)
2533 || (uniq == 2 && count >= 5)
2534 || (uniq == 3 && count >= 6)))
2536 /* Optimize the case where all the case values fit in a
2537 word without having to subtract MINVAL. In this case,
2538 we can optimize away the subtraction. */
2539 if (compare_tree_int (minval, 0) > 0
2540 && compare_tree_int (maxval, GET_MODE_BITSIZE (word_mode)) < 0)
2542 minval = integer_zero_node;
2545 emit_case_bit_tests (index_type, index_expr, minval, range,
2546 case_list, default_label);
2549 /* If range of values is much bigger than number of values,
2550 make a sequence of conditional branches instead of a dispatch.
2551 If the switch-index is a constant, do it this way
2552 because we can optimize it. */
2554 else if (count < case_values_threshold ()
2555 || compare_tree_int (range,
2556 (optimize_size ? 3 : 10) * count) > 0
2557 /* RANGE may be signed, and really large ranges will show up
2558 as negative numbers. */
2559 || compare_tree_int (range, 0) < 0
2560 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
2563 || TREE_CONSTANT (index_expr)
2564 /* If neither casesi or tablejump is available, we can
2565 only go this way. */
2566 || (!HAVE_casesi && !HAVE_tablejump))
2568 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
2570 /* If the index is a short or char that we do not have
2571 an insn to handle comparisons directly, convert it to
2572 a full integer now, rather than letting each comparison
2573 generate the conversion. */
2575 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
2576 && ! have_insn_for (COMPARE, GET_MODE (index)))
2578 enum machine_mode wider_mode;
2579 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
2580 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
2581 if (have_insn_for (COMPARE, wider_mode))
2583 index = convert_to_mode (wider_mode, index, unsignedp);
2588 do_pending_stack_adjust ();
2591 index = copy_to_reg (index);
2592 if (GET_CODE (index) == CONST_INT
2593 || TREE_CODE (index_expr) == INTEGER_CST)
2595 /* Make a tree node with the proper constant value
2596 if we don't already have one. */
2597 if (TREE_CODE (index_expr) != INTEGER_CST)
2600 = build_int_2 (INTVAL (index),
2601 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
2602 index_expr = convert (index_type, index_expr);
2605 /* For constant index expressions we need only
2606 issue an unconditional branch to the appropriate
2607 target code. The job of removing any unreachable
2608 code is left to the optimization phase if the
2609 "-O" option is specified. */
2610 for (n = case_list; n; n = n->right)
2611 if (! tree_int_cst_lt (index_expr, n->low)
2612 && ! tree_int_cst_lt (n->high, index_expr))
2616 emit_jump (label_rtx (n->code_label));
2618 emit_jump (default_label);
2622 /* If the index expression is not constant we generate
2623 a binary decision tree to select the appropriate
2624 target code. This is done as follows:
2626 The list of cases is rearranged into a binary tree,
2627 nearly optimal assuming equal probability for each case.
2629 The tree is transformed into RTL, eliminating
2630 redundant test conditions at the same time.
2632 If program flow could reach the end of the
2633 decision tree an unconditional jump to the
2634 default code is emitted. */
2637 = (TREE_CODE (orig_type) != ENUMERAL_TYPE
2638 && estimate_case_costs (case_list));
2639 balance_case_nodes (&case_list, NULL);
2640 emit_case_nodes (index, case_list, default_label, index_type);
2641 emit_jump (default_label);
2646 table_label = gen_label_rtx ();
2647 if (! try_casesi (index_type, index_expr, minval, range,
2648 table_label, default_label))
2650 index_type = integer_type_node;
2652 /* Index jumptables from zero for suitable values of
2653 minval to avoid a subtraction. */
2655 && compare_tree_int (minval, 0) > 0
2656 && compare_tree_int (minval, 3) < 0)
2658 minval = integer_zero_node;
2662 if (! try_tablejump (index_type, index_expr, minval, range,
2663 table_label, default_label))
2667 /* Get table of labels to jump to, in order of case index. */
2669 ncases = tree_low_cst (range, 0) + 1;
2670 labelvec = alloca (ncases * sizeof (rtx));
2671 memset (labelvec, 0, ncases * sizeof (rtx));
2673 for (n = case_list; n; n = n->right)
2675 /* Compute the low and high bounds relative to the minimum
2676 value since that should fit in a HOST_WIDE_INT while the
2677 actual values may not. */
2679 = tree_low_cst (fold (build2 (MINUS_EXPR, index_type,
2680 n->low, minval)), 1);
2681 HOST_WIDE_INT i_high
2682 = tree_low_cst (fold (build2 (MINUS_EXPR, index_type,
2683 n->high, minval)), 1);
2686 for (i = i_low; i <= i_high; i ++)
2688 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
2691 /* Fill in the gaps with the default. */
2692 for (i = 0; i < ncases; i++)
2693 if (labelvec[i] == 0)
2694 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
2696 /* Output the table. */
2697 emit_label (table_label);
2699 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
2700 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
2701 gen_rtx_LABEL_REF (Pmode, table_label),
2702 gen_rtvec_v (ncases, labelvec),
2703 const0_rtx, const0_rtx));
2705 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
2706 gen_rtvec_v (ncases, labelvec)));
2708 /* If the case insn drops through the table,
2709 after the table we must jump to the default-label.
2710 Otherwise record no drop-through after the table. */
2711 #ifdef CASE_DROPS_THROUGH
2712 emit_jump (default_label);
2718 before_case = NEXT_INSN (before_case);
2719 end = get_last_insn ();
2720 if (squeeze_notes (&before_case, &end))
2722 reorder_insns (before_case, end, start);
2728 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
2731 do_jump_if_equal (rtx op1, rtx op2, rtx label, int unsignedp)
2733 if (GET_CODE (op1) == CONST_INT && GET_CODE (op2) == CONST_INT)
2739 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX,
2740 (GET_MODE (op1) == VOIDmode
2741 ? GET_MODE (op2) : GET_MODE (op1)),
2745 /* Not all case values are encountered equally. This function
2746 uses a heuristic to weight case labels, in cases where that
2747 looks like a reasonable thing to do.
2749 Right now, all we try to guess is text, and we establish the
2752 chars above space: 16
2761 If we find any cases in the switch that are not either -1 or in the range
2762 of valid ASCII characters, or are control characters other than those
2763 commonly used with "\", don't treat this switch scanning text.
2765 Return 1 if these nodes are suitable for cost estimation, otherwise
2769 estimate_case_costs (case_node_ptr node)
2771 tree min_ascii = integer_minus_one_node;
2772 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
2776 /* If we haven't already made the cost table, make it now. Note that the
2777 lower bound of the table is -1, not zero. */
2779 if (! cost_table_initialized)
2781 cost_table_initialized = 1;
2783 for (i = 0; i < 128; i++)
2786 COST_TABLE (i) = 16;
2787 else if (ISPUNCT (i))
2789 else if (ISCNTRL (i))
2790 COST_TABLE (i) = -1;
2793 COST_TABLE (' ') = 8;
2794 COST_TABLE ('\t') = 4;
2795 COST_TABLE ('\0') = 4;
2796 COST_TABLE ('\n') = 2;
2797 COST_TABLE ('\f') = 1;
2798 COST_TABLE ('\v') = 1;
2799 COST_TABLE ('\b') = 1;
2802 /* See if all the case expressions look like text. It is text if the
2803 constant is >= -1 and the highest constant is <= 127. Do all comparisons
2804 as signed arithmetic since we don't want to ever access cost_table with a
2805 value less than -1. Also check that none of the constants in a range
2806 are strange control characters. */
2808 for (n = node; n; n = n->right)
2810 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
2813 for (i = (HOST_WIDE_INT) TREE_INT_CST_LOW (n->low);
2814 i <= (HOST_WIDE_INT) TREE_INT_CST_LOW (n->high); i++)
2815 if (COST_TABLE (i) < 0)
2819 /* All interesting values are within the range of interesting
2820 ASCII characters. */
2824 /* Take an ordered list of case nodes
2825 and transform them into a near optimal binary tree,
2826 on the assumption that any target code selection value is as
2827 likely as any other.
2829 The transformation is performed by splitting the ordered
2830 list into two equal sections plus a pivot. The parts are
2831 then attached to the pivot as left and right branches. Each
2832 branch is then transformed recursively. */
2835 balance_case_nodes (case_node_ptr *head, case_node_ptr parent)
2848 /* Count the number of entries on branch. Also count the ranges. */
2852 if (!tree_int_cst_equal (np->low, np->high))
2856 cost += COST_TABLE (TREE_INT_CST_LOW (np->high));
2860 cost += COST_TABLE (TREE_INT_CST_LOW (np->low));
2868 /* Split this list if it is long enough for that to help. */
2873 /* Find the place in the list that bisects the list's total cost,
2874 Here I gets half the total cost. */
2879 /* Skip nodes while their cost does not reach that amount. */
2880 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
2881 i -= COST_TABLE (TREE_INT_CST_LOW ((*npp)->high));
2882 i -= COST_TABLE (TREE_INT_CST_LOW ((*npp)->low));
2885 npp = &(*npp)->right;
2890 /* Leave this branch lopsided, but optimize left-hand
2891 side and fill in `parent' fields for right-hand side. */
2893 np->parent = parent;
2894 balance_case_nodes (&np->left, np);
2895 for (; np->right; np = np->right)
2896 np->right->parent = np;
2900 /* If there are just three nodes, split at the middle one. */
2902 npp = &(*npp)->right;
2905 /* Find the place in the list that bisects the list's total cost,
2906 where ranges count as 2.
2907 Here I gets half the total cost. */
2908 i = (i + ranges + 1) / 2;
2911 /* Skip nodes while their cost does not reach that amount. */
2912 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
2917 npp = &(*npp)->right;
2922 np->parent = parent;
2925 /* Optimize each of the two split parts. */
2926 balance_case_nodes (&np->left, np);
2927 balance_case_nodes (&np->right, np);
2931 /* Else leave this branch as one level,
2932 but fill in `parent' fields. */
2934 np->parent = parent;
2935 for (; np->right; np = np->right)
2936 np->right->parent = np;
2941 /* Search the parent sections of the case node tree
2942 to see if a test for the lower bound of NODE would be redundant.
2943 INDEX_TYPE is the type of the index expression.
2945 The instructions to generate the case decision tree are
2946 output in the same order as nodes are processed so it is
2947 known that if a parent node checks the range of the current
2948 node minus one that the current node is bounded at its lower
2949 span. Thus the test would be redundant. */
2952 node_has_low_bound (case_node_ptr node, tree index_type)
2955 case_node_ptr pnode;
2957 /* If the lower bound of this node is the lowest value in the index type,
2958 we need not test it. */
2960 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
2963 /* If this node has a left branch, the value at the left must be less
2964 than that at this node, so it cannot be bounded at the bottom and
2965 we need not bother testing any further. */
2970 low_minus_one = fold (build2 (MINUS_EXPR, TREE_TYPE (node->low),
2971 node->low, integer_one_node));
2973 /* If the subtraction above overflowed, we can't verify anything.
2974 Otherwise, look for a parent that tests our value - 1. */
2976 if (! tree_int_cst_lt (low_minus_one, node->low))
2979 for (pnode = node->parent; pnode; pnode = pnode->parent)
2980 if (tree_int_cst_equal (low_minus_one, pnode->high))
2986 /* Search the parent sections of the case node tree
2987 to see if a test for the upper bound of NODE would be redundant.
2988 INDEX_TYPE is the type of the index expression.
2990 The instructions to generate the case decision tree are
2991 output in the same order as nodes are processed so it is
2992 known that if a parent node checks the range of the current
2993 node plus one that the current node is bounded at its upper
2994 span. Thus the test would be redundant. */
2997 node_has_high_bound (case_node_ptr node, tree index_type)
3000 case_node_ptr pnode;
3002 /* If there is no upper bound, obviously no test is needed. */
3004 if (TYPE_MAX_VALUE (index_type) == NULL)
3007 /* If the upper bound of this node is the highest value in the type
3008 of the index expression, we need not test against it. */
3010 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
3013 /* If this node has a right branch, the value at the right must be greater
3014 than that at this node, so it cannot be bounded at the top and
3015 we need not bother testing any further. */
3020 high_plus_one = fold (build2 (PLUS_EXPR, TREE_TYPE (node->high),
3021 node->high, integer_one_node));
3023 /* If the addition above overflowed, we can't verify anything.
3024 Otherwise, look for a parent that tests our value + 1. */
3026 if (! tree_int_cst_lt (node->high, high_plus_one))
3029 for (pnode = node->parent; pnode; pnode = pnode->parent)
3030 if (tree_int_cst_equal (high_plus_one, pnode->low))
3036 /* Search the parent sections of the
3037 case node tree to see if both tests for the upper and lower
3038 bounds of NODE would be redundant. */
3041 node_is_bounded (case_node_ptr node, tree index_type)
3043 return (node_has_low_bound (node, index_type)
3044 && node_has_high_bound (node, index_type));
3047 /* Emit step-by-step code to select a case for the value of INDEX.
3048 The thus generated decision tree follows the form of the
3049 case-node binary tree NODE, whose nodes represent test conditions.
3050 INDEX_TYPE is the type of the index of the switch.
3052 Care is taken to prune redundant tests from the decision tree
3053 by detecting any boundary conditions already checked by
3054 emitted rtx. (See node_has_high_bound, node_has_low_bound
3055 and node_is_bounded, above.)
3057 Where the test conditions can be shown to be redundant we emit
3058 an unconditional jump to the target code. As a further
3059 optimization, the subordinates of a tree node are examined to
3060 check for bounded nodes. In this case conditional and/or
3061 unconditional jumps as a result of the boundary check for the
3062 current node are arranged to target the subordinates associated
3063 code for out of bound conditions on the current node.
3065 We can assume that when control reaches the code generated here,
3066 the index value has already been compared with the parents
3067 of this node, and determined to be on the same side of each parent
3068 as this node is. Thus, if this node tests for the value 51,
3069 and a parent tested for 52, we don't need to consider
3070 the possibility of a value greater than 51. If another parent
3071 tests for the value 50, then this node need not test anything. */
3074 emit_case_nodes (rtx index, case_node_ptr node, rtx default_label,
3077 /* If INDEX has an unsigned type, we must make unsigned branches. */
3078 int unsignedp = TYPE_UNSIGNED (index_type);
3079 enum machine_mode mode = GET_MODE (index);
3080 enum machine_mode imode = TYPE_MODE (index_type);
3082 /* See if our parents have already tested everything for us.
3083 If they have, emit an unconditional jump for this node. */
3084 if (node_is_bounded (node, index_type))
3085 emit_jump (label_rtx (node->code_label));
3087 else if (tree_int_cst_equal (node->low, node->high))
3089 /* Node is single valued. First see if the index expression matches
3090 this node and then check our children, if any. */
3092 do_jump_if_equal (index,
3093 convert_modes (mode, imode,
3094 expand_expr (node->low, NULL_RTX,
3097 label_rtx (node->code_label), unsignedp);
3099 if (node->right != 0 && node->left != 0)
3101 /* This node has children on both sides.
3102 Dispatch to one side or the other
3103 by comparing the index value with this node's value.
3104 If one subtree is bounded, check that one first,
3105 so we can avoid real branches in the tree. */
3107 if (node_is_bounded (node->right, index_type))
3109 emit_cmp_and_jump_insns (index,
3112 expand_expr (node->high, NULL_RTX,
3115 GT, NULL_RTX, mode, unsignedp,
3116 label_rtx (node->right->code_label));
3117 emit_case_nodes (index, node->left, default_label, index_type);
3120 else if (node_is_bounded (node->left, index_type))
3122 emit_cmp_and_jump_insns (index,
3125 expand_expr (node->high, NULL_RTX,
3128 LT, NULL_RTX, mode, unsignedp,
3129 label_rtx (node->left->code_label));
3130 emit_case_nodes (index, node->right, default_label, index_type);
3133 /* If both children are single-valued cases with no
3134 children, finish up all the work. This way, we can save
3135 one ordered comparison. */
3136 else if (tree_int_cst_equal (node->right->low, node->right->high)
3137 && node->right->left == 0
3138 && node->right->right == 0
3139 && tree_int_cst_equal (node->left->low, node->left->high)
3140 && node->left->left == 0
3141 && node->left->right == 0)
3143 /* Neither node is bounded. First distinguish the two sides;
3144 then emit the code for one side at a time. */
3146 /* See if the value matches what the right hand side
3148 do_jump_if_equal (index,
3149 convert_modes (mode, imode,
3150 expand_expr (node->right->low,
3154 label_rtx (node->right->code_label),
3157 /* See if the value matches what the left hand side
3159 do_jump_if_equal (index,
3160 convert_modes (mode, imode,
3161 expand_expr (node->left->low,
3165 label_rtx (node->left->code_label),
3171 /* Neither node is bounded. First distinguish the two sides;
3172 then emit the code for one side at a time. */
3174 tree test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
3176 /* See if the value is on the right. */
3177 emit_cmp_and_jump_insns (index,
3180 expand_expr (node->high, NULL_RTX,
3183 GT, NULL_RTX, mode, unsignedp,
3184 label_rtx (test_label));
3186 /* Value must be on the left.
3187 Handle the left-hand subtree. */
3188 emit_case_nodes (index, node->left, default_label, index_type);
3189 /* If left-hand subtree does nothing,
3191 emit_jump (default_label);
3193 /* Code branches here for the right-hand subtree. */
3194 expand_label (test_label);
3195 emit_case_nodes (index, node->right, default_label, index_type);
3199 else if (node->right != 0 && node->left == 0)
3201 /* Here we have a right child but no left so we issue conditional
3202 branch to default and process the right child.
3204 Omit the conditional branch to default if we it avoid only one
3205 right child; it costs too much space to save so little time. */
3207 if (node->right->right || node->right->left
3208 || !tree_int_cst_equal (node->right->low, node->right->high))
3210 if (!node_has_low_bound (node, index_type))
3212 emit_cmp_and_jump_insns (index,
3215 expand_expr (node->high, NULL_RTX,
3218 LT, NULL_RTX, mode, unsignedp,
3222 emit_case_nodes (index, node->right, default_label, index_type);
3225 /* We cannot process node->right normally
3226 since we haven't ruled out the numbers less than
3227 this node's value. So handle node->right explicitly. */
3228 do_jump_if_equal (index,
3231 expand_expr (node->right->low, NULL_RTX,
3234 label_rtx (node->right->code_label), unsignedp);
3237 else if (node->right == 0 && node->left != 0)
3239 /* Just one subtree, on the left. */
3240 if (node->left->left || node->left->right
3241 || !tree_int_cst_equal (node->left->low, node->left->high))
3243 if (!node_has_high_bound (node, index_type))
3245 emit_cmp_and_jump_insns (index,
3248 expand_expr (node->high, NULL_RTX,
3251 GT, NULL_RTX, mode, unsignedp,
3255 emit_case_nodes (index, node->left, default_label, index_type);
3258 /* We cannot process node->left normally
3259 since we haven't ruled out the numbers less than
3260 this node's value. So handle node->left explicitly. */
3261 do_jump_if_equal (index,
3264 expand_expr (node->left->low, NULL_RTX,
3267 label_rtx (node->left->code_label), unsignedp);
3272 /* Node is a range. These cases are very similar to those for a single
3273 value, except that we do not start by testing whether this node
3274 is the one to branch to. */
3276 if (node->right != 0 && node->left != 0)
3278 /* Node has subtrees on both sides.
3279 If the right-hand subtree is bounded,
3280 test for it first, since we can go straight there.
3281 Otherwise, we need to make a branch in the control structure,
3282 then handle the two subtrees. */
3283 tree test_label = 0;
3285 if (node_is_bounded (node->right, index_type))
3286 /* Right hand node is fully bounded so we can eliminate any
3287 testing and branch directly to the target code. */
3288 emit_cmp_and_jump_insns (index,
3291 expand_expr (node->high, NULL_RTX,
3294 GT, NULL_RTX, mode, unsignedp,
3295 label_rtx (node->right->code_label));
3298 /* Right hand node requires testing.
3299 Branch to a label where we will handle it later. */
3301 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
3302 emit_cmp_and_jump_insns (index,
3305 expand_expr (node->high, NULL_RTX,
3308 GT, NULL_RTX, mode, unsignedp,
3309 label_rtx (test_label));
3312 /* Value belongs to this node or to the left-hand subtree. */
3314 emit_cmp_and_jump_insns (index,
3317 expand_expr (node->low, NULL_RTX,
3320 GE, NULL_RTX, mode, unsignedp,
3321 label_rtx (node->code_label));
3323 /* Handle the left-hand subtree. */
3324 emit_case_nodes (index, node->left, default_label, index_type);
3326 /* If right node had to be handled later, do that now. */
3330 /* If the left-hand subtree fell through,
3331 don't let it fall into the right-hand subtree. */
3332 emit_jump (default_label);
3334 expand_label (test_label);
3335 emit_case_nodes (index, node->right, default_label, index_type);
3339 else if (node->right != 0 && node->left == 0)
3341 /* Deal with values to the left of this node,
3342 if they are possible. */
3343 if (!node_has_low_bound (node, index_type))
3345 emit_cmp_and_jump_insns (index,
3348 expand_expr (node->low, NULL_RTX,
3351 LT, NULL_RTX, mode, unsignedp,
3355 /* Value belongs to this node or to the right-hand subtree. */
3357 emit_cmp_and_jump_insns (index,
3360 expand_expr (node->high, NULL_RTX,
3363 LE, NULL_RTX, mode, unsignedp,
3364 label_rtx (node->code_label));
3366 emit_case_nodes (index, node->right, default_label, index_type);
3369 else if (node->right == 0 && node->left != 0)
3371 /* Deal with values to the right of this node,
3372 if they are possible. */
3373 if (!node_has_high_bound (node, index_type))
3375 emit_cmp_and_jump_insns (index,
3378 expand_expr (node->high, NULL_RTX,
3381 GT, NULL_RTX, mode, unsignedp,
3385 /* Value belongs to this node or to the left-hand subtree. */
3387 emit_cmp_and_jump_insns (index,
3390 expand_expr (node->low, NULL_RTX,
3393 GE, NULL_RTX, mode, unsignedp,
3394 label_rtx (node->code_label));
3396 emit_case_nodes (index, node->left, default_label, index_type);
3401 /* Node has no children so we check low and high bounds to remove
3402 redundant tests. Only one of the bounds can exist,
3403 since otherwise this node is bounded--a case tested already. */
3404 int high_bound = node_has_high_bound (node, index_type);
3405 int low_bound = node_has_low_bound (node, index_type);
3407 if (!high_bound && low_bound)
3409 emit_cmp_and_jump_insns (index,
3412 expand_expr (node->high, NULL_RTX,
3415 GT, NULL_RTX, mode, unsignedp,
3419 else if (!low_bound && high_bound)
3421 emit_cmp_and_jump_insns (index,
3424 expand_expr (node->low, NULL_RTX,
3427 LT, NULL_RTX, mode, unsignedp,
3430 else if (!low_bound && !high_bound)
3432 /* Widen LOW and HIGH to the same width as INDEX. */
3433 tree type = lang_hooks.types.type_for_mode (mode, unsignedp);
3434 tree low = build1 (CONVERT_EXPR, type, node->low);
3435 tree high = build1 (CONVERT_EXPR, type, node->high);
3436 rtx low_rtx, new_index, new_bound;
3438 /* Instead of doing two branches, emit one unsigned branch for
3439 (index-low) > (high-low). */
3440 low_rtx = expand_expr (low, NULL_RTX, mode, 0);
3441 new_index = expand_simple_binop (mode, MINUS, index, low_rtx,
3442 NULL_RTX, unsignedp,
3444 new_bound = expand_expr (fold (build2 (MINUS_EXPR, type,
3448 emit_cmp_and_jump_insns (new_index, new_bound, GT, NULL_RTX,
3449 mode, 1, default_label);
3452 emit_jump (label_rtx (node->code_label));