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, 2005, 2006, 2007
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 2, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to the Free
20 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
23 /* This file handles the generation of rtl code from tree structure
24 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
25 The functions whose names start with `expand_' are called by the
26 expander to generate RTL instructions for various kinds of constructs. */
30 #include "coretypes.h"
34 #include "hard-reg-set.h"
40 #include "insn-config.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 tree_conflicts_with_clobbers_p (tree
, 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 void expand_value_return (rtx
);
115 static int estimate_case_costs (case_node_ptr
);
116 static bool lshift_cheap_p (void);
117 static int case_bit_test_cmp (const void *, const void *);
118 static void emit_case_bit_tests (tree
, tree
, tree
, tree
, case_node_ptr
, rtx
);
119 static void balance_case_nodes (case_node_ptr
*, case_node_ptr
);
120 static int node_has_low_bound (case_node_ptr
, tree
);
121 static int node_has_high_bound (case_node_ptr
, tree
);
122 static int node_is_bounded (case_node_ptr
, tree
);
123 static void emit_case_nodes (rtx
, case_node_ptr
, rtx
, tree
);
124 static struct case_node
*add_case_node (struct case_node
*, 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_normal (exp
);
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_loc (tree string
, int vol
, location_t locus
)
267 if (TREE_CODE (string
) == ADDR_EXPR
)
268 string
= TREE_OPERAND (string
, 0);
270 body
= gen_rtx_ASM_INPUT_loc (VOIDmode
,
271 ggc_strdup (TREE_STRING_POINTER (string
)),
274 MEM_VOLATILE_P (body
) = vol
;
279 /* Parse the output constraint pointed to by *CONSTRAINT_P. It is the
280 OPERAND_NUMth output operand, indexed from zero. There are NINPUTS
281 inputs and NOUTPUTS outputs to this extended-asm. Upon return,
282 *ALLOWS_MEM will be TRUE iff the constraint allows the use of a
283 memory operand. Similarly, *ALLOWS_REG will be TRUE iff the
284 constraint allows the use of a register operand. And, *IS_INOUT
285 will be true if the operand is read-write, i.e., if it is used as
286 an input as well as an output. If *CONSTRAINT_P is not in
287 canonical form, it will be made canonical. (Note that `+' will be
288 replaced with `=' as part of this process.)
290 Returns TRUE if all went well; FALSE if an error occurred. */
293 parse_output_constraint (const char **constraint_p
, int operand_num
,
294 int ninputs
, int noutputs
, bool *allows_mem
,
295 bool *allows_reg
, bool *is_inout
)
297 const char *constraint
= *constraint_p
;
300 /* Assume the constraint doesn't allow the use of either a register
305 /* Allow the `=' or `+' to not be at the beginning of the string,
306 since it wasn't explicitly documented that way, and there is a
307 large body of code that puts it last. Swap the character to
308 the front, so as not to uglify any place else. */
309 p
= strchr (constraint
, '=');
311 p
= strchr (constraint
, '+');
313 /* If the string doesn't contain an `=', issue an error
317 error ("output operand constraint lacks %<=%>");
321 /* If the constraint begins with `+', then the operand is both read
322 from and written to. */
323 *is_inout
= (*p
== '+');
325 /* Canonicalize the output constraint so that it begins with `='. */
326 if (p
!= constraint
|| *is_inout
)
329 size_t c_len
= strlen (constraint
);
332 warning (0, "output constraint %qc for operand %d "
333 "is not at the beginning",
336 /* Make a copy of the constraint. */
337 buf
= alloca (c_len
+ 1);
338 strcpy (buf
, constraint
);
339 /* Swap the first character and the `=' or `+'. */
340 buf
[p
- constraint
] = buf
[0];
341 /* Make sure the first character is an `='. (Until we do this,
342 it might be a `+'.) */
344 /* Replace the constraint with the canonicalized string. */
345 *constraint_p
= ggc_alloc_string (buf
, c_len
);
346 constraint
= *constraint_p
;
349 /* Loop through the constraint string. */
350 for (p
= constraint
+ 1; *p
; p
+= CONSTRAINT_LEN (*p
, p
))
355 error ("operand constraint contains incorrectly positioned "
360 if (operand_num
+ 1 == ninputs
+ noutputs
)
362 error ("%<%%%> constraint used with last operand");
367 case 'V': case 'm': case 'o':
371 case '?': case '!': case '*': case '&': case '#':
372 case 'E': case 'F': case 'G': case 'H':
373 case 's': case 'i': case 'n':
374 case 'I': case 'J': case 'K': case 'L': case 'M':
375 case 'N': case 'O': case 'P': case ',':
378 case '0': case '1': case '2': case '3': case '4':
379 case '5': case '6': case '7': case '8': case '9':
381 error ("matching constraint not valid in output operand");
385 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
386 excepting those that expand_call created. So match memory
403 if (REG_CLASS_FROM_CONSTRAINT (*p
, p
) != NO_REGS
)
405 #ifdef EXTRA_CONSTRAINT_STR
406 else if (EXTRA_ADDRESS_CONSTRAINT (*p
, p
))
408 else if (EXTRA_MEMORY_CONSTRAINT (*p
, p
))
412 /* Otherwise we can't assume anything about the nature of
413 the constraint except that it isn't purely registers.
414 Treat it like "g" and hope for the best. */
425 /* Similar, but for input constraints. */
428 parse_input_constraint (const char **constraint_p
, int input_num
,
429 int ninputs
, int noutputs
, int ninout
,
430 const char * const * constraints
,
431 bool *allows_mem
, bool *allows_reg
)
433 const char *constraint
= *constraint_p
;
434 const char *orig_constraint
= constraint
;
435 size_t c_len
= strlen (constraint
);
437 bool saw_match
= false;
439 /* Assume the constraint doesn't allow the use of either
440 a register or memory. */
444 /* Make sure constraint has neither `=', `+', nor '&'. */
446 for (j
= 0; j
< c_len
; j
+= CONSTRAINT_LEN (constraint
[j
], constraint
+j
))
447 switch (constraint
[j
])
449 case '+': case '=': case '&':
450 if (constraint
== orig_constraint
)
452 error ("input operand constraint contains %qc", constraint
[j
]);
458 if (constraint
== orig_constraint
459 && input_num
+ 1 == ninputs
- ninout
)
461 error ("%<%%%> constraint used with last operand");
466 case 'V': case 'm': case 'o':
471 case '?': case '!': case '*': case '#':
472 case 'E': case 'F': case 'G': case 'H':
473 case 's': case 'i': case 'n':
474 case 'I': case 'J': case 'K': case 'L': case 'M':
475 case 'N': case 'O': case 'P': case ',':
478 /* Whether or not a numeric constraint allows a register is
479 decided by the matching constraint, and so there is no need
480 to do anything special with them. We must handle them in
481 the default case, so that we don't unnecessarily force
482 operands to memory. */
483 case '0': case '1': case '2': case '3': case '4':
484 case '5': case '6': case '7': case '8': case '9':
491 match
= strtoul (constraint
+ j
, &end
, 10);
492 if (match
>= (unsigned long) noutputs
)
494 error ("matching constraint references invalid operand number");
498 /* Try and find the real constraint for this dup. Only do this
499 if the matching constraint is the only alternative. */
501 && (j
== 0 || (j
== 1 && constraint
[0] == '%')))
503 constraint
= constraints
[match
];
504 *constraint_p
= constraint
;
505 c_len
= strlen (constraint
);
507 /* ??? At the end of the loop, we will skip the first part of
508 the matched constraint. This assumes not only that the
509 other constraint is an output constraint, but also that
510 the '=' or '+' come first. */
514 j
= end
- constraint
;
515 /* Anticipate increment at end of loop. */
530 if (! ISALPHA (constraint
[j
]))
532 error ("invalid punctuation %qc in constraint", constraint
[j
]);
535 if (REG_CLASS_FROM_CONSTRAINT (constraint
[j
], constraint
+ j
)
538 #ifdef EXTRA_CONSTRAINT_STR
539 else if (EXTRA_ADDRESS_CONSTRAINT (constraint
[j
], constraint
+ j
))
541 else if (EXTRA_MEMORY_CONSTRAINT (constraint
[j
], constraint
+ j
))
545 /* Otherwise we can't assume anything about the nature of
546 the constraint except that it isn't purely registers.
547 Treat it like "g" and hope for the best. */
555 if (saw_match
&& !*allows_reg
)
556 warning (0, "matching constraint does not allow a register");
561 /* Return DECL iff there's an overlap between *REGS and DECL, where DECL
562 can be an asm-declared register. Called via walk_tree. */
565 decl_overlaps_hard_reg_set_p (tree
*declp
, int *walk_subtrees ATTRIBUTE_UNUSED
,
569 const HARD_REG_SET
*regs
= data
;
571 if (TREE_CODE (decl
) == VAR_DECL
)
573 if (DECL_HARD_REGISTER (decl
)
574 && REG_P (DECL_RTL (decl
))
575 && REGNO (DECL_RTL (decl
)) < FIRST_PSEUDO_REGISTER
)
577 rtx reg
= DECL_RTL (decl
);
579 if (overlaps_hard_reg_set_p (*regs
, GET_MODE (reg
), REGNO (reg
)))
584 else if (TYPE_P (decl
) || TREE_CODE (decl
) == PARM_DECL
)
589 /* If there is an overlap between *REGS and DECL, return the first overlap
592 tree_overlaps_hard_reg_set (tree decl
, HARD_REG_SET
*regs
)
594 return walk_tree (&decl
, decl_overlaps_hard_reg_set_p
, regs
, NULL
);
597 /* Check for overlap between registers marked in CLOBBERED_REGS and
598 anything inappropriate in T. Emit error and return the register
599 variable definition for error, NULL_TREE for ok. */
602 tree_conflicts_with_clobbers_p (tree t
, HARD_REG_SET
*clobbered_regs
)
604 /* Conflicts between asm-declared register variables and the clobber
605 list are not allowed. */
606 tree overlap
= tree_overlaps_hard_reg_set (t
, clobbered_regs
);
610 error ("asm-specifier for variable %qs conflicts with asm clobber list",
611 IDENTIFIER_POINTER (DECL_NAME (overlap
)));
613 /* Reset registerness to stop multiple errors emitted for a single
615 DECL_REGISTER (overlap
) = 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 (outputs
, inputs
, 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
))
694 if (TREE_VALUE (tail
) == error_mark_node
)
696 regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
698 i
= decode_reg_name (regname
);
699 if (i
>= 0 || i
== -4)
702 error ("unknown register name %qs in %<asm%>", regname
);
704 /* Mark clobbered registers. */
707 /* Clobbering the PIC register is an error. */
708 if (i
== (int) PIC_OFFSET_TABLE_REGNUM
)
710 error ("PIC register %qs clobbered in %<asm%>", regname
);
714 SET_HARD_REG_BIT (clobbered_regs
, i
);
718 /* First pass over inputs and outputs checks validity and sets
719 mark_addressable if needed. */
722 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
724 tree val
= TREE_VALUE (tail
);
725 tree type
= TREE_TYPE (val
);
726 const char *constraint
;
731 /* If there's an erroneous arg, emit no insn. */
732 if (type
== error_mark_node
)
735 /* Try to parse the output constraint. If that fails, there's
736 no point in going further. */
737 constraint
= constraints
[i
];
738 if (!parse_output_constraint (&constraint
, i
, ninputs
, noutputs
,
739 &allows_mem
, &allows_reg
, &is_inout
))
746 && REG_P (DECL_RTL (val
))
747 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
))))
748 lang_hooks
.mark_addressable (val
);
755 if (ninputs
+ noutputs
> MAX_RECOG_OPERANDS
)
757 error ("more than %d operands in %<asm%>", MAX_RECOG_OPERANDS
);
761 for (i
= 0, tail
= inputs
; tail
; i
++, tail
= TREE_CHAIN (tail
))
763 bool allows_reg
, allows_mem
;
764 const char *constraint
;
766 /* If there's an erroneous arg, emit no insn, because the ASM_INPUT
767 would get VOIDmode and that could cause a crash in reload. */
768 if (TREE_TYPE (TREE_VALUE (tail
)) == error_mark_node
)
771 constraint
= constraints
[i
+ noutputs
];
772 if (! parse_input_constraint (&constraint
, i
, ninputs
, noutputs
, ninout
,
773 constraints
, &allows_mem
, &allows_reg
))
776 if (! allows_reg
&& allows_mem
)
777 lang_hooks
.mark_addressable (TREE_VALUE (tail
));
780 /* Second pass evaluates arguments. */
783 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
785 tree val
= TREE_VALUE (tail
);
786 tree type
= TREE_TYPE (val
);
793 ok
= parse_output_constraint (&constraints
[i
], i
, ninputs
,
794 noutputs
, &allows_mem
, &allows_reg
,
798 /* If an output operand is not a decl or indirect ref and our constraint
799 allows a register, make a temporary to act as an intermediate.
800 Make the asm insn write into that, then our caller will copy it to
801 the real output operand. Likewise for promoted variables. */
803 generating_concat_p
= 0;
805 real_output_rtx
[i
] = NULL_RTX
;
806 if ((TREE_CODE (val
) == INDIRECT_REF
809 && (allows_mem
|| REG_P (DECL_RTL (val
)))
810 && ! (REG_P (DECL_RTL (val
))
811 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
)))
815 op
= expand_expr (val
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
817 op
= validize_mem (op
);
819 if (! allows_reg
&& !MEM_P (op
))
820 error ("output number %d not directly addressable", i
);
821 if ((! allows_mem
&& MEM_P (op
))
822 || GET_CODE (op
) == CONCAT
)
824 real_output_rtx
[i
] = op
;
825 op
= gen_reg_rtx (GET_MODE (op
));
827 emit_move_insn (op
, real_output_rtx
[i
]);
832 op
= assign_temp (type
, 0, 0, 1);
833 op
= validize_mem (op
);
834 TREE_VALUE (tail
) = make_tree (type
, op
);
838 generating_concat_p
= old_generating_concat_p
;
842 inout_mode
[ninout
] = TYPE_MODE (type
);
843 inout_opnum
[ninout
++] = i
;
846 if (tree_conflicts_with_clobbers_p (val
, &clobbered_regs
))
847 clobber_conflict_found
= 1;
850 /* Make vectors for the expression-rtx, constraint strings,
851 and named operands. */
853 argvec
= rtvec_alloc (ninputs
);
854 constraintvec
= rtvec_alloc (ninputs
);
856 body
= gen_rtx_ASM_OPERANDS ((noutputs
== 0 ? VOIDmode
857 : GET_MODE (output_rtx
[0])),
858 ggc_strdup (TREE_STRING_POINTER (string
)),
859 empty_string
, 0, argvec
, constraintvec
,
862 MEM_VOLATILE_P (body
) = vol
;
864 /* Eval the inputs and put them into ARGVEC.
865 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
867 for (i
= 0, tail
= inputs
; tail
; tail
= TREE_CHAIN (tail
), ++i
)
869 bool allows_reg
, allows_mem
;
870 const char *constraint
;
875 constraint
= constraints
[i
+ noutputs
];
876 ok
= parse_input_constraint (&constraint
, i
, ninputs
, noutputs
, ninout
,
877 constraints
, &allows_mem
, &allows_reg
);
880 generating_concat_p
= 0;
882 val
= TREE_VALUE (tail
);
883 type
= TREE_TYPE (val
);
884 /* EXPAND_INITIALIZER will not generate code for valid initializer
885 constants, but will still generate code for other types of operand.
886 This is the behavior we want for constant constraints. */
887 op
= expand_expr (val
, NULL_RTX
, VOIDmode
,
888 allows_reg
? EXPAND_NORMAL
889 : allows_mem
? EXPAND_MEMORY
890 : EXPAND_INITIALIZER
);
892 /* Never pass a CONCAT to an ASM. */
893 if (GET_CODE (op
) == CONCAT
)
894 op
= force_reg (GET_MODE (op
), op
);
896 op
= validize_mem (op
);
898 if (asm_operand_ok (op
, constraint
) <= 0)
900 if (allows_reg
&& TYPE_MODE (type
) != BLKmode
)
901 op
= force_reg (TYPE_MODE (type
), op
);
902 else if (!allows_mem
)
903 warning (0, "asm operand %d probably doesn%'t match constraints",
907 /* We won't recognize either volatile memory or memory
908 with a queued address as available a memory_operand
909 at this point. Ignore it: clearly this *is* a memory. */
913 warning (0, "use of memory input without lvalue in "
914 "asm operand %d is deprecated", i
+ noutputs
);
918 rtx mem
= force_const_mem (TYPE_MODE (type
), op
);
920 op
= validize_mem (mem
);
922 op
= force_reg (TYPE_MODE (type
), op
);
925 || GET_CODE (op
) == SUBREG
926 || GET_CODE (op
) == CONCAT
)
928 tree qual_type
= build_qualified_type (type
,
931 rtx memloc
= assign_temp (qual_type
, 1, 1, 1);
932 memloc
= validize_mem (memloc
);
933 emit_move_insn (memloc
, op
);
939 generating_concat_p
= old_generating_concat_p
;
940 ASM_OPERANDS_INPUT (body
, i
) = op
;
942 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body
, i
)
943 = gen_rtx_ASM_INPUT (TYPE_MODE (type
),
944 ggc_strdup (constraints
[i
+ noutputs
]));
946 if (tree_conflicts_with_clobbers_p (val
, &clobbered_regs
))
947 clobber_conflict_found
= 1;
950 /* Protect all the operands from the queue now that they have all been
953 generating_concat_p
= 0;
955 /* For in-out operands, copy output rtx to input rtx. */
956 for (i
= 0; i
< ninout
; i
++)
958 int j
= inout_opnum
[i
];
961 ASM_OPERANDS_INPUT (body
, ninputs
- ninout
+ i
)
964 sprintf (buffer
, "%d", j
);
965 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body
, ninputs
- ninout
+ i
)
966 = gen_rtx_ASM_INPUT (inout_mode
[i
], ggc_strdup (buffer
));
969 generating_concat_p
= old_generating_concat_p
;
971 /* Now, for each output, construct an rtx
972 (set OUTPUT (asm_operands INSN OUTPUTCONSTRAINT OUTPUTNUMBER
973 ARGVEC CONSTRAINTS OPNAMES))
974 If there is more than one, put them inside a PARALLEL. */
976 if (noutputs
== 1 && nclobbers
== 0)
978 ASM_OPERANDS_OUTPUT_CONSTRAINT (body
) = ggc_strdup (constraints
[0]);
979 emit_insn (gen_rtx_SET (VOIDmode
, output_rtx
[0], body
));
982 else if (noutputs
== 0 && nclobbers
== 0)
984 /* No output operands: put in a raw ASM_OPERANDS rtx. */
996 body
= gen_rtx_PARALLEL (VOIDmode
, rtvec_alloc (num
+ nclobbers
));
998 /* For each output operand, store a SET. */
999 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1001 XVECEXP (body
, 0, i
)
1002 = gen_rtx_SET (VOIDmode
,
1004 gen_rtx_ASM_OPERANDS
1005 (GET_MODE (output_rtx
[i
]),
1006 ggc_strdup (TREE_STRING_POINTER (string
)),
1007 ggc_strdup (constraints
[i
]),
1008 i
, argvec
, constraintvec
, locus
));
1010 MEM_VOLATILE_P (SET_SRC (XVECEXP (body
, 0, i
))) = vol
;
1013 /* If there are no outputs (but there are some clobbers)
1014 store the bare ASM_OPERANDS into the PARALLEL. */
1017 XVECEXP (body
, 0, i
++) = obody
;
1019 /* Store (clobber REG) for each clobbered register specified. */
1021 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1023 const char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1024 int j
= decode_reg_name (regname
);
1029 if (j
== -3) /* `cc', which is not a register */
1032 if (j
== -4) /* `memory', don't cache memory across asm */
1034 XVECEXP (body
, 0, i
++)
1035 = gen_rtx_CLOBBER (VOIDmode
,
1038 gen_rtx_SCRATCH (VOIDmode
)));
1042 /* Ignore unknown register, error already signaled. */
1046 /* Use QImode since that's guaranteed to clobber just one reg. */
1047 clobbered_reg
= gen_rtx_REG (QImode
, j
);
1049 /* Do sanity check for overlap between clobbers and respectively
1050 input and outputs that hasn't been handled. Such overlap
1051 should have been detected and reported above. */
1052 if (!clobber_conflict_found
)
1056 /* We test the old body (obody) contents to avoid tripping
1057 over the under-construction body. */
1058 for (opno
= 0; opno
< noutputs
; opno
++)
1059 if (reg_overlap_mentioned_p (clobbered_reg
, output_rtx
[opno
]))
1060 internal_error ("asm clobber conflict with output operand");
1062 for (opno
= 0; opno
< ninputs
- ninout
; opno
++)
1063 if (reg_overlap_mentioned_p (clobbered_reg
,
1064 ASM_OPERANDS_INPUT (obody
, opno
)))
1065 internal_error ("asm clobber conflict with input operand");
1068 XVECEXP (body
, 0, i
++)
1069 = gen_rtx_CLOBBER (VOIDmode
, clobbered_reg
);
1075 /* For any outputs that needed reloading into registers, spill them
1076 back to where they belong. */
1077 for (i
= 0; i
< noutputs
; ++i
)
1078 if (real_output_rtx
[i
])
1079 emit_move_insn (real_output_rtx
[i
], output_rtx
[i
]);
1085 expand_asm_expr (tree exp
)
1091 if (ASM_INPUT_P (exp
))
1093 expand_asm_loc (ASM_STRING (exp
), ASM_VOLATILE_P (exp
), input_location
);
1097 outputs
= ASM_OUTPUTS (exp
);
1098 noutputs
= list_length (outputs
);
1099 /* o[I] is the place that output number I should be written. */
1100 o
= (tree
*) alloca (noutputs
* sizeof (tree
));
1102 /* Record the contents of OUTPUTS before it is modified. */
1103 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1104 o
[i
] = TREE_VALUE (tail
);
1106 /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
1107 OUTPUTS some trees for where the values were actually stored. */
1108 expand_asm_operands (ASM_STRING (exp
), outputs
, ASM_INPUTS (exp
),
1109 ASM_CLOBBERS (exp
), ASM_VOLATILE_P (exp
),
1112 /* Copy all the intermediate outputs into the specified outputs. */
1113 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1115 if (o
[i
] != TREE_VALUE (tail
))
1117 expand_assignment (o
[i
], TREE_VALUE (tail
));
1120 /* Restore the original value so that it's correct the next
1121 time we expand this function. */
1122 TREE_VALUE (tail
) = o
[i
];
1127 /* A subroutine of expand_asm_operands. Check that all operands have
1128 the same number of alternatives. Return true if so. */
1131 check_operand_nalternatives (tree outputs
, tree inputs
)
1133 if (outputs
|| inputs
)
1135 tree tmp
= TREE_PURPOSE (outputs
? outputs
: inputs
);
1137 = n_occurrences (',', TREE_STRING_POINTER (TREE_VALUE (tmp
)));
1140 if (nalternatives
+ 1 > MAX_RECOG_ALTERNATIVES
)
1142 error ("too many alternatives in %<asm%>");
1149 const char *constraint
1150 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tmp
)));
1152 if (n_occurrences (',', constraint
) != nalternatives
)
1154 error ("operand constraints for %<asm%> differ "
1155 "in number of alternatives");
1159 if (TREE_CHAIN (tmp
))
1160 tmp
= TREE_CHAIN (tmp
);
1162 tmp
= next
, next
= 0;
1169 /* A subroutine of expand_asm_operands. Check that all operand names
1170 are unique. Return true if so. We rely on the fact that these names
1171 are identifiers, and so have been canonicalized by get_identifier,
1172 so all we need are pointer comparisons. */
1175 check_unique_operand_names (tree outputs
, tree inputs
)
1179 for (i
= outputs
; 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
))))
1190 for (i
= inputs
; i
; i
= TREE_CHAIN (i
))
1192 tree i_name
= TREE_PURPOSE (TREE_PURPOSE (i
));
1196 for (j
= TREE_CHAIN (i
); j
; j
= TREE_CHAIN (j
))
1197 if (simple_cst_equal (i_name
, TREE_PURPOSE (TREE_PURPOSE (j
))))
1199 for (j
= outputs
; j
; j
= TREE_CHAIN (j
))
1200 if (simple_cst_equal (i_name
, TREE_PURPOSE (TREE_PURPOSE (j
))))
1207 error ("duplicate asm operand name %qs",
1208 TREE_STRING_POINTER (TREE_PURPOSE (TREE_PURPOSE (i
))));
1212 /* A subroutine of expand_asm_operands. Resolve the names of the operands
1213 in *POUTPUTS and *PINPUTS to numbers, and replace the name expansions in
1214 STRING and in the constraints to those numbers. */
1217 resolve_asm_operand_names (tree string
, tree outputs
, tree inputs
)
1224 check_unique_operand_names (outputs
, inputs
);
1226 /* Substitute [<name>] in input constraint strings. There should be no
1227 named operands in output constraints. */
1228 for (t
= inputs
; t
; t
= TREE_CHAIN (t
))
1230 c
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t
)));
1231 if (strchr (c
, '[') != NULL
)
1233 p
= buffer
= xstrdup (c
);
1234 while ((p
= strchr (p
, '[')) != NULL
)
1235 p
= resolve_operand_name_1 (p
, outputs
, inputs
);
1236 TREE_VALUE (TREE_PURPOSE (t
))
1237 = build_string (strlen (buffer
), buffer
);
1242 /* Now check for any needed substitutions in the template. */
1243 c
= TREE_STRING_POINTER (string
);
1244 while ((c
= strchr (c
, '%')) != NULL
)
1248 else if (ISALPHA (c
[1]) && c
[2] == '[')
1259 /* OK, we need to make a copy so we can perform the substitutions.
1260 Assume that we will not need extra space--we get to remove '['
1261 and ']', which means we cannot have a problem until we have more
1262 than 999 operands. */
1263 buffer
= xstrdup (TREE_STRING_POINTER (string
));
1264 p
= buffer
+ (c
- TREE_STRING_POINTER (string
));
1266 while ((p
= strchr (p
, '%')) != NULL
)
1270 else if (ISALPHA (p
[1]) && p
[2] == '[')
1278 p
= resolve_operand_name_1 (p
, outputs
, inputs
);
1281 string
= build_string (strlen (buffer
), buffer
);
1288 /* A subroutine of resolve_operand_names. P points to the '[' for a
1289 potential named operand of the form [<name>]. In place, replace
1290 the name and brackets with a number. Return a pointer to the
1291 balance of the string after substitution. */
1294 resolve_operand_name_1 (char *p
, tree outputs
, tree inputs
)
1301 /* Collect the operand name. */
1302 q
= strchr (p
, ']');
1305 error ("missing close brace for named operand");
1306 return strchr (p
, '\0');
1310 /* Resolve the name to a number. */
1311 for (op
= 0, t
= outputs
; t
; t
= TREE_CHAIN (t
), op
++)
1313 tree name
= TREE_PURPOSE (TREE_PURPOSE (t
));
1316 const char *c
= TREE_STRING_POINTER (name
);
1317 if (strncmp (c
, p
+ 1, len
) == 0 && c
[len
] == '\0')
1321 for (t
= inputs
; t
; t
= TREE_CHAIN (t
), op
++)
1323 tree name
= TREE_PURPOSE (TREE_PURPOSE (t
));
1326 const char *c
= TREE_STRING_POINTER (name
);
1327 if (strncmp (c
, p
+ 1, len
) == 0 && c
[len
] == '\0')
1333 error ("undefined named operand %qs", p
+ 1);
1337 /* Replace the name with the number. Unfortunately, not all libraries
1338 get the return value of sprintf correct, so search for the end of the
1339 generated string by hand. */
1340 sprintf (p
, "%d", op
);
1341 p
= strchr (p
, '\0');
1343 /* Verify the no extra buffer space assumption. */
1344 gcc_assert (p
<= q
);
1346 /* Shift the rest of the buffer down to fill the gap. */
1347 memmove (p
, q
+ 1, strlen (q
+ 1) + 1);
1352 /* Generate RTL to evaluate the expression EXP. */
1355 expand_expr_stmt (tree exp
)
1360 value
= expand_expr (exp
, const0_rtx
, VOIDmode
, EXPAND_NORMAL
);
1361 if (GIMPLE_TUPLE_P (exp
))
1362 type
= void_type_node
;
1364 type
= TREE_TYPE (exp
);
1366 /* If all we do is reference a volatile value in memory,
1367 copy it to a register to be sure it is actually touched. */
1368 if (value
&& MEM_P (value
) && TREE_THIS_VOLATILE (exp
))
1370 if (TYPE_MODE (type
) == VOIDmode
)
1372 else if (TYPE_MODE (type
) != BLKmode
)
1373 value
= copy_to_reg (value
);
1376 rtx lab
= gen_label_rtx ();
1378 /* Compare the value with itself to reference it. */
1379 emit_cmp_and_jump_insns (value
, value
, EQ
,
1380 expand_normal (TYPE_SIZE (type
)),
1386 /* Free any temporaries used to evaluate this expression. */
1390 /* Warn if EXP contains any computations whose results are not used.
1391 Return 1 if a warning is printed; 0 otherwise. LOCUS is the
1392 (potential) location of the expression. */
1395 warn_if_unused_value (tree exp
, location_t locus
)
1398 if (TREE_USED (exp
) || TREE_NO_WARNING (exp
))
1401 /* Don't warn about void constructs. This includes casting to void,
1402 void function calls, and statement expressions with a final cast
1404 if (VOID_TYPE_P (TREE_TYPE (exp
)))
1407 if (EXPR_HAS_LOCATION (exp
))
1408 locus
= EXPR_LOCATION (exp
);
1410 switch (TREE_CODE (exp
))
1412 case PREINCREMENT_EXPR
:
1413 case POSTINCREMENT_EXPR
:
1414 case PREDECREMENT_EXPR
:
1415 case POSTDECREMENT_EXPR
:
1417 case GIMPLE_MODIFY_STMT
:
1421 case TRY_CATCH_EXPR
:
1422 case WITH_CLEANUP_EXPR
:
1428 /* For a binding, warn if no side effect within it. */
1429 exp
= BIND_EXPR_BODY (exp
);
1433 exp
= TREE_OPERAND (exp
, 0);
1436 case TRUTH_ORIF_EXPR
:
1437 case TRUTH_ANDIF_EXPR
:
1438 /* In && or ||, warn if 2nd operand has no side effect. */
1439 exp
= TREE_OPERAND (exp
, 1);
1443 if (warn_if_unused_value (TREE_OPERAND (exp
, 0), locus
))
1445 /* Let people do `(foo (), 0)' without a warning. */
1446 if (TREE_CONSTANT (TREE_OPERAND (exp
, 1)))
1448 exp
= TREE_OPERAND (exp
, 1);
1452 /* If this is an expression with side effects, don't warn; this
1453 case commonly appears in macro expansions. */
1454 if (TREE_SIDE_EFFECTS (exp
))
1459 /* Don't warn about automatic dereferencing of references, since
1460 the user cannot control it. */
1461 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp
, 0))) == REFERENCE_TYPE
)
1463 exp
= TREE_OPERAND (exp
, 0);
1469 /* Referencing a volatile value is a side effect, so don't warn. */
1470 if ((DECL_P (exp
) || REFERENCE_CLASS_P (exp
))
1471 && TREE_THIS_VOLATILE (exp
))
1474 /* If this is an expression which has no operands, there is no value
1475 to be unused. There are no such language-independent codes,
1476 but front ends may define such. */
1477 if (EXPRESSION_CLASS_P (exp
) && TREE_OPERAND_LENGTH (exp
) == 0)
1481 warning (0, "%Hvalue computed is not used", &locus
);
1487 /* Generate RTL to return from the current function, with no value.
1488 (That is, we do not do anything about returning any value.) */
1491 expand_null_return (void)
1493 /* If this function was declared to return a value, but we
1494 didn't, clobber the return registers so that they are not
1495 propagated live to the rest of the function. */
1496 clobber_return_register ();
1498 expand_null_return_1 ();
1501 /* Generate RTL to return directly from the current function.
1502 (That is, we bypass any return value.) */
1505 expand_naked_return (void)
1509 clear_pending_stack_adjust ();
1510 do_pending_stack_adjust ();
1512 end_label
= naked_return_label
;
1514 end_label
= naked_return_label
= gen_label_rtx ();
1516 emit_jump (end_label
);
1519 /* Generate RTL to return from the current function, with value VAL. */
1522 expand_value_return (rtx val
)
1524 /* Copy the value to the return location
1525 unless it's already there. */
1527 rtx return_reg
= DECL_RTL (DECL_RESULT (current_function_decl
));
1528 if (return_reg
!= val
)
1530 tree type
= TREE_TYPE (DECL_RESULT (current_function_decl
));
1531 if (targetm
.calls
.promote_function_return (TREE_TYPE (current_function_decl
)))
1533 int unsignedp
= TYPE_UNSIGNED (type
);
1534 enum machine_mode old_mode
1535 = DECL_MODE (DECL_RESULT (current_function_decl
));
1536 enum machine_mode mode
1537 = promote_mode (type
, old_mode
, &unsignedp
, 1);
1539 if (mode
!= old_mode
)
1540 val
= convert_modes (mode
, old_mode
, val
, unsignedp
);
1542 if (GET_CODE (return_reg
) == PARALLEL
)
1543 emit_group_load (return_reg
, val
, type
, int_size_in_bytes (type
));
1545 emit_move_insn (return_reg
, val
);
1548 expand_null_return_1 ();
1551 /* Output a return with no value. */
1554 expand_null_return_1 (void)
1556 clear_pending_stack_adjust ();
1557 do_pending_stack_adjust ();
1558 emit_jump (return_label
);
1561 /* Generate RTL to evaluate the expression RETVAL and return it
1562 from the current function. */
1565 expand_return (tree retval
)
1571 /* If function wants no value, give it none. */
1572 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl
))) == VOID_TYPE
)
1574 expand_normal (retval
);
1575 expand_null_return ();
1579 if (retval
== error_mark_node
)
1581 /* Treat this like a return of no value from a function that
1583 expand_null_return ();
1586 else if ((TREE_CODE (retval
) == GIMPLE_MODIFY_STMT
1587 || TREE_CODE (retval
) == INIT_EXPR
)
1588 && TREE_CODE (GENERIC_TREE_OPERAND (retval
, 0)) == RESULT_DECL
)
1589 retval_rhs
= GENERIC_TREE_OPERAND (retval
, 1);
1591 retval_rhs
= retval
;
1593 result_rtl
= DECL_RTL (DECL_RESULT (current_function_decl
));
1595 /* If we are returning the RESULT_DECL, then the value has already
1596 been stored into it, so we don't have to do anything special. */
1597 if (TREE_CODE (retval_rhs
) == RESULT_DECL
)
1598 expand_value_return (result_rtl
);
1600 /* If the result is an aggregate that is being returned in one (or more)
1601 registers, load the registers here. The compiler currently can't handle
1602 copying a BLKmode value into registers. We could put this code in a
1603 more general area (for use by everyone instead of just function
1604 call/return), but until this feature is generally usable it is kept here
1605 (and in expand_call). */
1607 else if (retval_rhs
!= 0
1608 && TYPE_MODE (GENERIC_TREE_TYPE (retval_rhs
)) == BLKmode
1609 && REG_P (result_rtl
))
1612 unsigned HOST_WIDE_INT bitpos
, xbitpos
;
1613 unsigned HOST_WIDE_INT padding_correction
= 0;
1614 unsigned HOST_WIDE_INT bytes
1615 = int_size_in_bytes (TREE_TYPE (retval_rhs
));
1616 int n_regs
= (bytes
+ UNITS_PER_WORD
- 1) / UNITS_PER_WORD
;
1617 unsigned int bitsize
1618 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs
)), BITS_PER_WORD
);
1619 rtx
*result_pseudos
= alloca (sizeof (rtx
) * n_regs
);
1620 rtx result_reg
, src
= NULL_RTX
, dst
= NULL_RTX
;
1621 rtx result_val
= expand_normal (retval_rhs
);
1622 enum machine_mode tmpmode
, result_reg_mode
;
1626 expand_null_return ();
1630 /* If the structure doesn't take up a whole number of words, see
1631 whether the register value should be padded on the left or on
1632 the right. Set PADDING_CORRECTION to the number of padding
1633 bits needed on the left side.
1635 In most ABIs, the structure will be returned at the least end of
1636 the register, which translates to right padding on little-endian
1637 targets and left padding on big-endian targets. The opposite
1638 holds if the structure is returned at the most significant
1639 end of the register. */
1640 if (bytes
% UNITS_PER_WORD
!= 0
1641 && (targetm
.calls
.return_in_msb (TREE_TYPE (retval_rhs
))
1643 : BYTES_BIG_ENDIAN
))
1644 padding_correction
= (BITS_PER_WORD
- ((bytes
% UNITS_PER_WORD
)
1647 /* Copy the structure BITSIZE bits at a time. */
1648 for (bitpos
= 0, xbitpos
= padding_correction
;
1649 bitpos
< bytes
* BITS_PER_UNIT
;
1650 bitpos
+= bitsize
, xbitpos
+= bitsize
)
1652 /* We need a new destination pseudo each time xbitpos is
1653 on a word boundary and when xbitpos == padding_correction
1654 (the first time through). */
1655 if (xbitpos
% BITS_PER_WORD
== 0
1656 || xbitpos
== padding_correction
)
1658 /* Generate an appropriate register. */
1659 dst
= gen_reg_rtx (word_mode
);
1660 result_pseudos
[xbitpos
/ BITS_PER_WORD
] = dst
;
1662 /* Clear the destination before we move anything into it. */
1663 emit_move_insn (dst
, CONST0_RTX (GET_MODE (dst
)));
1666 /* We need a new source operand each time bitpos is on a word
1668 if (bitpos
% BITS_PER_WORD
== 0)
1669 src
= operand_subword_force (result_val
,
1670 bitpos
/ BITS_PER_WORD
,
1673 /* Use bitpos for the source extraction (left justified) and
1674 xbitpos for the destination store (right justified). */
1675 store_bit_field (dst
, bitsize
, xbitpos
% BITS_PER_WORD
, word_mode
,
1676 extract_bit_field (src
, bitsize
,
1677 bitpos
% BITS_PER_WORD
, 1,
1678 NULL_RTX
, word_mode
, word_mode
));
1681 tmpmode
= GET_MODE (result_rtl
);
1682 if (tmpmode
== BLKmode
)
1684 /* Find the smallest integer mode large enough to hold the
1685 entire structure and use that mode instead of BLKmode
1686 on the USE insn for the return register. */
1687 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
1688 tmpmode
!= VOIDmode
;
1689 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
1690 /* Have we found a large enough mode? */
1691 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
1694 /* A suitable mode should have been found. */
1695 gcc_assert (tmpmode
!= VOIDmode
);
1697 PUT_MODE (result_rtl
, tmpmode
);
1700 if (GET_MODE_SIZE (tmpmode
) < GET_MODE_SIZE (word_mode
))
1701 result_reg_mode
= word_mode
;
1703 result_reg_mode
= tmpmode
;
1704 result_reg
= gen_reg_rtx (result_reg_mode
);
1706 for (i
= 0; i
< n_regs
; i
++)
1707 emit_move_insn (operand_subword (result_reg
, i
, 0, result_reg_mode
),
1710 if (tmpmode
!= result_reg_mode
)
1711 result_reg
= gen_lowpart (tmpmode
, result_reg
);
1713 expand_value_return (result_reg
);
1715 else if (retval_rhs
!= 0
1716 && !VOID_TYPE_P (TREE_TYPE (retval_rhs
))
1717 && (REG_P (result_rtl
)
1718 || (GET_CODE (result_rtl
) == PARALLEL
)))
1720 /* Calculate the return value into a temporary (usually a pseudo
1722 tree ot
= TREE_TYPE (DECL_RESULT (current_function_decl
));
1723 tree nt
= build_qualified_type (ot
, TYPE_QUALS (ot
) | TYPE_QUAL_CONST
);
1725 val
= assign_temp (nt
, 0, 0, 1);
1726 val
= expand_expr (retval_rhs
, val
, GET_MODE (val
), EXPAND_NORMAL
);
1727 val
= force_not_mem (val
);
1728 /* Return the calculated value. */
1729 expand_value_return (val
);
1733 /* No hard reg used; calculate value into hard return reg. */
1734 expand_expr (retval
, const0_rtx
, VOIDmode
, EXPAND_NORMAL
);
1735 expand_value_return (result_rtl
);
1739 /* Given a pointer to a BLOCK node return nonzero if (and only if) the node
1740 in question represents the outermost pair of curly braces (i.e. the "body
1741 block") of a function or method.
1743 For any BLOCK node representing a "body block" of a function or method, the
1744 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
1745 represents the outermost (function) scope for the function or method (i.e.
1746 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
1747 *that* node in turn will point to the relevant FUNCTION_DECL node. */
1750 is_body_block (tree stmt
)
1752 if (lang_hooks
.no_body_blocks
)
1755 if (TREE_CODE (stmt
) == BLOCK
)
1757 tree parent
= BLOCK_SUPERCONTEXT (stmt
);
1759 if (parent
&& TREE_CODE (parent
) == BLOCK
)
1761 tree grandparent
= BLOCK_SUPERCONTEXT (parent
);
1763 if (grandparent
&& TREE_CODE (grandparent
) == FUNCTION_DECL
)
1771 /* Emit code to restore vital registers at the beginning of a nonlocal goto
1774 expand_nl_goto_receiver (void)
1776 /* Clobber the FP when we get here, so we have to make sure it's
1777 marked as used by this function. */
1778 emit_insn (gen_rtx_USE (VOIDmode
, hard_frame_pointer_rtx
));
1780 /* Mark the static chain as clobbered here so life information
1781 doesn't get messed up for it. */
1782 emit_insn (gen_rtx_CLOBBER (VOIDmode
, static_chain_rtx
));
1784 #ifdef HAVE_nonlocal_goto
1785 if (! HAVE_nonlocal_goto
)
1787 /* First adjust our frame pointer to its actual value. It was
1788 previously set to the start of the virtual area corresponding to
1789 the stacked variables when we branched here and now needs to be
1790 adjusted to the actual hardware fp value.
1792 Assignments are to virtual registers are converted by
1793 instantiate_virtual_regs into the corresponding assignment
1794 to the underlying register (fp in this case) that makes
1795 the original assignment true.
1796 So the following insn will actually be
1797 decrementing fp by STARTING_FRAME_OFFSET. */
1798 emit_move_insn (virtual_stack_vars_rtx
, hard_frame_pointer_rtx
);
1800 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
1801 if (fixed_regs
[ARG_POINTER_REGNUM
])
1803 #ifdef ELIMINABLE_REGS
1804 /* If the argument pointer can be eliminated in favor of the
1805 frame pointer, we don't need to restore it. We assume here
1806 that if such an elimination is present, it can always be used.
1807 This is the case on all known machines; if we don't make this
1808 assumption, we do unnecessary saving on many machines. */
1809 static const struct elims
{const int from
, to
;} elim_regs
[] = ELIMINABLE_REGS
;
1812 for (i
= 0; i
< ARRAY_SIZE (elim_regs
); i
++)
1813 if (elim_regs
[i
].from
== ARG_POINTER_REGNUM
1814 && elim_regs
[i
].to
== HARD_FRAME_POINTER_REGNUM
)
1817 if (i
== ARRAY_SIZE (elim_regs
))
1820 /* Now restore our arg pointer from the address at which it
1821 was saved in our stack frame. */
1822 emit_move_insn (virtual_incoming_args_rtx
,
1823 copy_to_reg (get_arg_pointer_save_area (cfun
)));
1828 #ifdef HAVE_nonlocal_goto_receiver
1829 if (HAVE_nonlocal_goto_receiver
)
1830 emit_insn (gen_nonlocal_goto_receiver ());
1833 /* @@@ This is a kludge. Not all machine descriptions define a blockage
1834 insn, but we must not allow the code we just generated to be reordered
1835 by scheduling. Specifically, the update of the frame pointer must
1836 happen immediately, not later. So emit an ASM_INPUT to act as blockage
1838 emit_insn (gen_rtx_ASM_INPUT (VOIDmode
, ""));
1841 /* Generate RTL for the automatic variable declaration DECL.
1842 (Other kinds of declarations are simply ignored if seen here.) */
1845 expand_decl (tree decl
)
1849 type
= TREE_TYPE (decl
);
1851 /* For a CONST_DECL, set mode, alignment, and sizes from those of the
1852 type in case this node is used in a reference. */
1853 if (TREE_CODE (decl
) == CONST_DECL
)
1855 DECL_MODE (decl
) = TYPE_MODE (type
);
1856 DECL_ALIGN (decl
) = TYPE_ALIGN (type
);
1857 DECL_SIZE (decl
) = TYPE_SIZE (type
);
1858 DECL_SIZE_UNIT (decl
) = TYPE_SIZE_UNIT (type
);
1862 /* Otherwise, only automatic variables need any expansion done. Static and
1863 external variables, and external functions, will be handled by
1864 `assemble_variable' (called from finish_decl). TYPE_DECL requires
1865 nothing. PARM_DECLs are handled in `assign_parms'. */
1866 if (TREE_CODE (decl
) != VAR_DECL
)
1869 if (TREE_STATIC (decl
) || DECL_EXTERNAL (decl
))
1872 /* Create the RTL representation for the variable. */
1874 if (type
== error_mark_node
)
1875 SET_DECL_RTL (decl
, gen_rtx_MEM (BLKmode
, const0_rtx
));
1877 else if (DECL_SIZE (decl
) == 0)
1878 /* Variable with incomplete type. */
1881 if (DECL_INITIAL (decl
) == 0)
1882 /* Error message was already done; now avoid a crash. */
1883 x
= gen_rtx_MEM (BLKmode
, const0_rtx
);
1885 /* An initializer is going to decide the size of this array.
1886 Until we know the size, represent its address with a reg. */
1887 x
= gen_rtx_MEM (BLKmode
, gen_reg_rtx (Pmode
));
1889 set_mem_attributes (x
, decl
, 1);
1890 SET_DECL_RTL (decl
, x
);
1892 else if (use_register_for_decl (decl
))
1894 /* Automatic variable that can go in a register. */
1895 int unsignedp
= TYPE_UNSIGNED (type
);
1896 enum machine_mode reg_mode
1897 = promote_mode (type
, DECL_MODE (decl
), &unsignedp
, 0);
1899 SET_DECL_RTL (decl
, gen_reg_rtx (reg_mode
));
1901 /* Note if the object is a user variable. */
1902 if (!DECL_ARTIFICIAL (decl
))
1904 mark_user_reg (DECL_RTL (decl
));
1906 /* Trust user variables which have a pointer type to really
1907 be pointers. Do not trust compiler generated temporaries
1908 as our type system is totally busted as it relates to
1909 pointer arithmetic which translates into lots of compiler
1910 generated objects with pointer types, but which are not really
1912 if (POINTER_TYPE_P (type
))
1913 mark_reg_pointer (DECL_RTL (decl
),
1914 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl
))));
1918 else if (TREE_CODE (DECL_SIZE_UNIT (decl
)) == INTEGER_CST
1919 && ! (flag_stack_check
&& ! STACK_CHECK_BUILTIN
1920 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl
),
1921 STACK_CHECK_MAX_VAR_SIZE
)))
1923 /* Variable of fixed size that goes on the stack. */
1928 /* If we previously made RTL for this decl, it must be an array
1929 whose size was determined by the initializer.
1930 The old address was a register; set that register now
1931 to the proper address. */
1932 if (DECL_RTL_SET_P (decl
))
1934 gcc_assert (MEM_P (DECL_RTL (decl
)));
1935 gcc_assert (REG_P (XEXP (DECL_RTL (decl
), 0)));
1936 oldaddr
= XEXP (DECL_RTL (decl
), 0);
1939 /* Set alignment we actually gave this decl. */
1940 DECL_ALIGN (decl
) = (DECL_MODE (decl
) == BLKmode
? BIGGEST_ALIGNMENT
1941 : GET_MODE_BITSIZE (DECL_MODE (decl
)));
1942 DECL_USER_ALIGN (decl
) = 0;
1944 x
= assign_temp (decl
, 1, 1, 1);
1945 set_mem_attributes (x
, decl
, 1);
1946 SET_DECL_RTL (decl
, x
);
1950 addr
= force_operand (XEXP (DECL_RTL (decl
), 0), oldaddr
);
1951 if (addr
!= oldaddr
)
1952 emit_move_insn (oldaddr
, addr
);
1956 /* Dynamic-size object: must push space on the stack. */
1958 rtx address
, size
, x
;
1960 /* Record the stack pointer on entry to block, if have
1961 not already done so. */
1962 do_pending_stack_adjust ();
1964 /* Compute the variable's size, in bytes. This will expand any
1965 needed SAVE_EXPRs for the first time. */
1966 size
= expand_normal (DECL_SIZE_UNIT (decl
));
1969 /* Allocate space on the stack for the variable. Note that
1970 DECL_ALIGN says how the variable is to be aligned and we
1971 cannot use it to conclude anything about the alignment of
1973 address
= allocate_dynamic_stack_space (size
, NULL_RTX
,
1974 TYPE_ALIGN (TREE_TYPE (decl
)));
1976 /* Reference the variable indirect through that rtx. */
1977 x
= gen_rtx_MEM (DECL_MODE (decl
), address
);
1978 set_mem_attributes (x
, decl
, 1);
1979 SET_DECL_RTL (decl
, x
);
1982 /* Indicate the alignment we actually gave this variable. */
1983 #ifdef STACK_BOUNDARY
1984 DECL_ALIGN (decl
) = STACK_BOUNDARY
;
1986 DECL_ALIGN (decl
) = BIGGEST_ALIGNMENT
;
1988 DECL_USER_ALIGN (decl
) = 0;
1992 /* Emit code to save the current value of stack. */
1994 expand_stack_save (void)
1998 do_pending_stack_adjust ();
1999 emit_stack_save (SAVE_BLOCK
, &ret
, NULL_RTX
);
2003 /* Emit code to restore the current value of stack. */
2005 expand_stack_restore (tree var
)
2007 rtx sa
= DECL_RTL (var
);
2009 emit_stack_restore (SAVE_BLOCK
, sa
, NULL_RTX
);
2012 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
2013 DECL_ELTS is the list of elements that belong to DECL's type.
2014 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
2017 expand_anon_union_decl (tree decl
, tree cleanup ATTRIBUTE_UNUSED
,
2023 /* If any of the elements are addressable, so is the entire union. */
2024 for (t
= decl_elts
; t
; t
= TREE_CHAIN (t
))
2025 if (TREE_ADDRESSABLE (TREE_VALUE (t
)))
2027 TREE_ADDRESSABLE (decl
) = 1;
2032 x
= DECL_RTL (decl
);
2034 /* Go through the elements, assigning RTL to each. */
2035 for (t
= decl_elts
; t
; t
= TREE_CHAIN (t
))
2037 tree decl_elt
= TREE_VALUE (t
);
2038 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (decl_elt
));
2041 /* If any of the elements are addressable, so is the entire
2043 if (TREE_USED (decl_elt
))
2044 TREE_USED (decl
) = 1;
2046 /* Propagate the union's alignment to the elements. */
2047 DECL_ALIGN (decl_elt
) = DECL_ALIGN (decl
);
2048 DECL_USER_ALIGN (decl_elt
) = DECL_USER_ALIGN (decl
);
2050 /* If the element has BLKmode and the union doesn't, the union is
2051 aligned such that the element doesn't need to have BLKmode, so
2052 change the element's mode to the appropriate one for its size. */
2053 if (mode
== BLKmode
&& DECL_MODE (decl
) != BLKmode
)
2054 DECL_MODE (decl_elt
) = mode
2055 = mode_for_size_tree (DECL_SIZE (decl_elt
), MODE_INT
, 1);
2057 if (mode
== GET_MODE (x
))
2060 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
2061 instead create a new MEM rtx with the proper mode. */
2062 decl_rtl
= adjust_address_nv (x
, mode
, 0);
2065 gcc_assert (REG_P (x
));
2066 decl_rtl
= gen_lowpart_SUBREG (mode
, x
);
2068 SET_DECL_RTL (decl_elt
, decl_rtl
);
2072 /* Do the insertion of a case label into case_list. The labels are
2073 fed to us in descending order from the sorted vector of case labels used
2074 in the tree part of the middle end. So the list we construct is
2075 sorted in ascending order. The bounds on the case range, LOW and HIGH,
2076 are converted to case's index type TYPE. */
2078 static struct case_node
*
2079 add_case_node (struct case_node
*head
, tree type
, tree low
, tree high
,
2082 tree min_value
, max_value
;
2083 struct case_node
*r
;
2085 gcc_assert (TREE_CODE (low
) == INTEGER_CST
);
2086 gcc_assert (!high
|| TREE_CODE (high
) == INTEGER_CST
);
2088 min_value
= TYPE_MIN_VALUE (type
);
2089 max_value
= TYPE_MAX_VALUE (type
);
2091 /* If there's no HIGH value, then this is not a case range; it's
2092 just a simple case label. But that's just a degenerate case
2094 If the bounds are equal, turn this into the one-value case. */
2095 if (!high
|| tree_int_cst_equal (low
, high
))
2097 /* If the simple case value is unreachable, ignore it. */
2098 if ((TREE_CODE (min_value
) == INTEGER_CST
2099 && tree_int_cst_compare (low
, min_value
) < 0)
2100 || (TREE_CODE (max_value
) == INTEGER_CST
2101 && tree_int_cst_compare (low
, max_value
) > 0))
2103 low
= fold_convert (type
, low
);
2108 /* If the entire case range is unreachable, ignore it. */
2109 if ((TREE_CODE (min_value
) == INTEGER_CST
2110 && tree_int_cst_compare (high
, min_value
) < 0)
2111 || (TREE_CODE (max_value
) == INTEGER_CST
2112 && tree_int_cst_compare (low
, max_value
) > 0))
2115 /* If the lower bound is less than the index type's minimum
2116 value, truncate the range bounds. */
2117 if (TREE_CODE (min_value
) == INTEGER_CST
2118 && tree_int_cst_compare (low
, min_value
) < 0)
2120 low
= fold_convert (type
, low
);
2122 /* If the upper bound is greater than the index type's maximum
2123 value, truncate the range bounds. */
2124 if (TREE_CODE (max_value
) == INTEGER_CST
2125 && tree_int_cst_compare (high
, max_value
) > 0)
2127 high
= fold_convert (type
, high
);
2131 /* Add this label to the chain. Make sure to drop overflow flags. */
2132 r
= ggc_alloc (sizeof (struct case_node
));
2133 r
->low
= build_int_cst_wide (TREE_TYPE (low
), TREE_INT_CST_LOW (low
),
2134 TREE_INT_CST_HIGH (low
));
2135 r
->high
= build_int_cst_wide (TREE_TYPE (high
), TREE_INT_CST_LOW (high
),
2136 TREE_INT_CST_HIGH (high
));
2137 r
->code_label
= label
;
2138 r
->parent
= r
->left
= NULL
;
2143 /* Maximum number of case bit tests. */
2144 #define MAX_CASE_BIT_TESTS 3
2146 /* By default, enable case bit tests on targets with ashlsi3. */
2147 #ifndef CASE_USE_BIT_TESTS
2148 #define CASE_USE_BIT_TESTS (ashl_optab->handlers[word_mode].insn_code \
2149 != CODE_FOR_nothing)
2153 /* A case_bit_test represents a set of case nodes that may be
2154 selected from using a bit-wise comparison. HI and LO hold
2155 the integer to be tested against, LABEL contains the label
2156 to jump to upon success and BITS counts the number of case
2157 nodes handled by this test, typically the number of bits
2160 struct case_bit_test
2168 /* Determine whether "1 << x" is relatively cheap in word_mode. */
2171 bool lshift_cheap_p (void)
2173 static bool init
= false;
2174 static bool cheap
= true;
2178 rtx reg
= gen_rtx_REG (word_mode
, 10000);
2179 int cost
= rtx_cost (gen_rtx_ASHIFT (word_mode
, const1_rtx
, reg
), SET
);
2180 cheap
= cost
< COSTS_N_INSNS (3);
2187 /* Comparison function for qsort to order bit tests by decreasing
2188 number of case nodes, i.e. the node with the most cases gets
2192 case_bit_test_cmp (const void *p1
, const void *p2
)
2194 const struct case_bit_test
*d1
= p1
;
2195 const struct case_bit_test
*d2
= p2
;
2197 if (d2
->bits
!= d1
->bits
)
2198 return d2
->bits
- d1
->bits
;
2200 /* Stabilize the sort. */
2201 return CODE_LABEL_NUMBER (d2
->label
) - CODE_LABEL_NUMBER (d1
->label
);
2204 /* Expand a switch statement by a short sequence of bit-wise
2205 comparisons. "switch(x)" is effectively converted into
2206 "if ((1 << (x-MINVAL)) & CST)" where CST and MINVAL are
2209 INDEX_EXPR is the value being switched on, which is of
2210 type INDEX_TYPE. MINVAL is the lowest case value of in
2211 the case nodes, of INDEX_TYPE type, and RANGE is highest
2212 value minus MINVAL, also of type INDEX_TYPE. NODES is
2213 the set of case nodes, and DEFAULT_LABEL is the label to
2214 branch to should none of the cases match.
2216 There *MUST* be MAX_CASE_BIT_TESTS or less unique case
2220 emit_case_bit_tests (tree index_type
, tree index_expr
, tree minval
,
2221 tree range
, case_node_ptr nodes
, rtx default_label
)
2223 struct case_bit_test test
[MAX_CASE_BIT_TESTS
];
2224 enum machine_mode mode
;
2225 rtx expr
, index
, label
;
2226 unsigned int i
,j
,lo
,hi
;
2227 struct case_node
*n
;
2231 for (n
= nodes
; n
; n
= n
->right
)
2233 label
= label_rtx (n
->code_label
);
2234 for (i
= 0; i
< count
; i
++)
2235 if (label
== test
[i
].label
)
2240 gcc_assert (count
< MAX_CASE_BIT_TESTS
);
2243 test
[i
].label
= label
;
2250 lo
= tree_low_cst (fold_build2 (MINUS_EXPR
, index_type
,
2251 n
->low
, minval
), 1);
2252 hi
= tree_low_cst (fold_build2 (MINUS_EXPR
, index_type
,
2253 n
->high
, minval
), 1);
2254 for (j
= lo
; j
<= hi
; j
++)
2255 if (j
>= HOST_BITS_PER_WIDE_INT
)
2256 test
[i
].hi
|= (HOST_WIDE_INT
) 1 << (j
- HOST_BITS_PER_INT
);
2258 test
[i
].lo
|= (HOST_WIDE_INT
) 1 << j
;
2261 qsort (test
, count
, sizeof(*test
), case_bit_test_cmp
);
2263 index_expr
= fold_build2 (MINUS_EXPR
, index_type
,
2264 fold_convert (index_type
, index_expr
),
2265 fold_convert (index_type
, minval
));
2266 index
= expand_normal (index_expr
);
2267 do_pending_stack_adjust ();
2269 mode
= TYPE_MODE (index_type
);
2270 expr
= expand_normal (range
);
2271 emit_cmp_and_jump_insns (index
, expr
, GTU
, NULL_RTX
, mode
, 1,
2274 index
= convert_to_mode (word_mode
, index
, 0);
2275 index
= expand_binop (word_mode
, ashl_optab
, const1_rtx
,
2276 index
, NULL_RTX
, 1, OPTAB_WIDEN
);
2278 for (i
= 0; i
< count
; i
++)
2280 expr
= immed_double_const (test
[i
].lo
, test
[i
].hi
, word_mode
);
2281 expr
= expand_binop (word_mode
, and_optab
, index
, expr
,
2282 NULL_RTX
, 1, OPTAB_WIDEN
);
2283 emit_cmp_and_jump_insns (expr
, const0_rtx
, NE
, NULL_RTX
,
2284 word_mode
, 1, test
[i
].label
);
2287 emit_jump (default_label
);
2291 #define HAVE_casesi 0
2294 #ifndef HAVE_tablejump
2295 #define HAVE_tablejump 0
2298 /* Terminate a case (Pascal/Ada) or switch (C) statement
2299 in which ORIG_INDEX is the expression to be tested.
2300 If ORIG_TYPE is not NULL, it is the original ORIG_INDEX
2301 type as given in the source before any compiler conversions.
2302 Generate the code to test it and jump to the right place. */
2305 expand_case (tree exp
)
2307 tree minval
= NULL_TREE
, maxval
= NULL_TREE
, range
= NULL_TREE
;
2308 rtx default_label
= 0;
2309 struct case_node
*n
;
2310 unsigned int count
, uniq
;
2316 rtx before_case
, end
, lab
;
2318 tree vec
= SWITCH_LABELS (exp
);
2319 tree orig_type
= TREE_TYPE (exp
);
2320 tree index_expr
= SWITCH_COND (exp
);
2321 tree index_type
= TREE_TYPE (index_expr
);
2322 int unsignedp
= TYPE_UNSIGNED (index_type
);
2324 /* The insn after which the case dispatch should finally
2325 be emitted. Zero for a dummy. */
2328 /* A list of case labels; it is first built as a list and it may then
2329 be rearranged into a nearly balanced binary tree. */
2330 struct case_node
*case_list
= 0;
2332 /* Label to jump to if no case matches. */
2333 tree default_label_decl
;
2335 /* The switch body is lowered in gimplify.c, we should never have
2336 switches with a non-NULL SWITCH_BODY here. */
2337 gcc_assert (!SWITCH_BODY (exp
));
2338 gcc_assert (SWITCH_LABELS (exp
));
2340 do_pending_stack_adjust ();
2342 /* An ERROR_MARK occurs for various reasons including invalid data type. */
2343 if (index_type
!= error_mark_node
)
2346 bitmap label_bitmap
;
2348 /* cleanup_tree_cfg removes all SWITCH_EXPR with their index
2349 expressions being INTEGER_CST. */
2350 gcc_assert (TREE_CODE (index_expr
) != INTEGER_CST
);
2352 /* The default case is at the end of TREE_VEC. */
2353 elt
= TREE_VEC_ELT (vec
, TREE_VEC_LENGTH (vec
) - 1);
2354 gcc_assert (!CASE_HIGH (elt
));
2355 gcc_assert (!CASE_LOW (elt
));
2356 default_label_decl
= CASE_LABEL (elt
);
2358 for (i
= TREE_VEC_LENGTH (vec
) - 1; --i
>= 0; )
2361 elt
= TREE_VEC_ELT (vec
, i
);
2363 low
= CASE_LOW (elt
);
2365 high
= CASE_HIGH (elt
);
2367 /* Discard empty ranges. */
2368 if (high
&& INT_CST_LT (high
, low
))
2371 case_list
= add_case_node (case_list
, index_type
, low
, high
,
2376 before_case
= start
= get_last_insn ();
2377 default_label
= label_rtx (default_label_decl
);
2379 /* Get upper and lower bounds of case values. */
2383 label_bitmap
= BITMAP_ALLOC (NULL
);
2384 for (n
= case_list
; n
; n
= n
->right
)
2386 /* Count the elements and track the largest and smallest
2387 of them (treating them as signed even if they are not). */
2395 if (INT_CST_LT (n
->low
, minval
))
2397 if (INT_CST_LT (maxval
, n
->high
))
2400 /* A range counts double, since it requires two compares. */
2401 if (! tree_int_cst_equal (n
->low
, n
->high
))
2404 /* If we have not seen this label yet, then increase the
2405 number of unique case node targets seen. */
2406 lab
= label_rtx (n
->code_label
);
2407 if (!bitmap_bit_p (label_bitmap
, CODE_LABEL_NUMBER (lab
)))
2409 bitmap_set_bit (label_bitmap
, CODE_LABEL_NUMBER (lab
));
2414 BITMAP_FREE (label_bitmap
);
2416 /* cleanup_tree_cfg removes all SWITCH_EXPR with a single
2417 destination, such as one with a default case only. However,
2418 it doesn't remove cases that are out of range for the switch
2419 type, so we may still get a zero here. */
2422 emit_jump (default_label
);
2426 /* Compute span of values. */
2427 range
= fold_build2 (MINUS_EXPR
, index_type
, maxval
, minval
);
2429 /* Try implementing this switch statement by a short sequence of
2430 bit-wise comparisons. However, we let the binary-tree case
2431 below handle constant index expressions. */
2432 if (CASE_USE_BIT_TESTS
2433 && ! TREE_CONSTANT (index_expr
)
2434 && compare_tree_int (range
, GET_MODE_BITSIZE (word_mode
)) < 0
2435 && compare_tree_int (range
, 0) > 0
2436 && lshift_cheap_p ()
2437 && ((uniq
== 1 && count
>= 3)
2438 || (uniq
== 2 && count
>= 5)
2439 || (uniq
== 3 && count
>= 6)))
2441 /* Optimize the case where all the case values fit in a
2442 word without having to subtract MINVAL. In this case,
2443 we can optimize away the subtraction. */
2444 if (compare_tree_int (minval
, 0) > 0
2445 && compare_tree_int (maxval
, GET_MODE_BITSIZE (word_mode
)) < 0)
2447 minval
= build_int_cst (index_type
, 0);
2450 emit_case_bit_tests (index_type
, index_expr
, minval
, range
,
2451 case_list
, default_label
);
2454 /* If range of values is much bigger than number of values,
2455 make a sequence of conditional branches instead of a dispatch.
2456 If the switch-index is a constant, do it this way
2457 because we can optimize it. */
2459 else if (count
< case_values_threshold ()
2460 || compare_tree_int (range
,
2461 (optimize_size
? 3 : 10) * count
) > 0
2462 /* RANGE may be signed, and really large ranges will show up
2463 as negative numbers. */
2464 || compare_tree_int (range
, 0) < 0
2465 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
2468 || !flag_jump_tables
2469 || TREE_CONSTANT (index_expr
)
2470 /* If neither casesi or tablejump is available, we can
2471 only go this way. */
2472 || (!HAVE_casesi
&& !HAVE_tablejump
))
2474 index
= expand_normal (index_expr
);
2476 /* If the index is a short or char that we do not have
2477 an insn to handle comparisons directly, convert it to
2478 a full integer now, rather than letting each comparison
2479 generate the conversion. */
2481 if (GET_MODE_CLASS (GET_MODE (index
)) == MODE_INT
2482 && ! have_insn_for (COMPARE
, GET_MODE (index
)))
2484 enum machine_mode wider_mode
;
2485 for (wider_mode
= GET_MODE (index
); wider_mode
!= VOIDmode
;
2486 wider_mode
= GET_MODE_WIDER_MODE (wider_mode
))
2487 if (have_insn_for (COMPARE
, wider_mode
))
2489 index
= convert_to_mode (wider_mode
, index
, unsignedp
);
2494 do_pending_stack_adjust ();
2497 index
= copy_to_reg (index
);
2499 /* We generate a binary decision tree to select the
2500 appropriate target code. This is done as follows:
2502 The list of cases is rearranged into a binary tree,
2503 nearly optimal assuming equal probability for each case.
2505 The tree is transformed into RTL, eliminating
2506 redundant test conditions at the same time.
2508 If program flow could reach the end of the
2509 decision tree an unconditional jump to the
2510 default code is emitted. */
2513 = (TREE_CODE (orig_type
) != ENUMERAL_TYPE
2514 && estimate_case_costs (case_list
));
2515 balance_case_nodes (&case_list
, NULL
);
2516 emit_case_nodes (index
, case_list
, default_label
, index_type
);
2517 emit_jump (default_label
);
2521 table_label
= gen_label_rtx ();
2522 if (! try_casesi (index_type
, index_expr
, minval
, range
,
2523 table_label
, default_label
))
2527 /* Index jumptables from zero for suitable values of
2528 minval to avoid a subtraction. */
2530 && compare_tree_int (minval
, 0) > 0
2531 && compare_tree_int (minval
, 3) < 0)
2533 minval
= build_int_cst (index_type
, 0);
2537 ok
= try_tablejump (index_type
, index_expr
, minval
, range
,
2538 table_label
, default_label
);
2542 /* Get table of labels to jump to, in order of case index. */
2544 ncases
= tree_low_cst (range
, 0) + 1;
2545 labelvec
= alloca (ncases
* sizeof (rtx
));
2546 memset (labelvec
, 0, ncases
* sizeof (rtx
));
2548 for (n
= case_list
; n
; n
= n
->right
)
2550 /* Compute the low and high bounds relative to the minimum
2551 value since that should fit in a HOST_WIDE_INT while the
2552 actual values may not. */
2554 = tree_low_cst (fold_build2 (MINUS_EXPR
, index_type
,
2555 n
->low
, minval
), 1);
2556 HOST_WIDE_INT i_high
2557 = tree_low_cst (fold_build2 (MINUS_EXPR
, index_type
,
2558 n
->high
, minval
), 1);
2561 for (i
= i_low
; i
<= i_high
; i
++)
2563 = gen_rtx_LABEL_REF (Pmode
, label_rtx (n
->code_label
));
2566 /* Fill in the gaps with the default. */
2567 for (i
= 0; i
< ncases
; i
++)
2568 if (labelvec
[i
] == 0)
2569 labelvec
[i
] = gen_rtx_LABEL_REF (Pmode
, default_label
);
2571 /* Output the table. */
2572 emit_label (table_label
);
2574 if (CASE_VECTOR_PC_RELATIVE
|| flag_pic
)
2575 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE
,
2576 gen_rtx_LABEL_REF (Pmode
, table_label
),
2577 gen_rtvec_v (ncases
, labelvec
),
2578 const0_rtx
, const0_rtx
));
2580 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE
,
2581 gen_rtvec_v (ncases
, labelvec
)));
2583 /* Record no drop-through after the table. */
2587 before_case
= NEXT_INSN (before_case
);
2588 end
= get_last_insn ();
2589 reorder_insns (before_case
, end
, start
);
2595 /* Generate code to jump to LABEL if OP0 and OP1 are equal in mode MODE. */
2598 do_jump_if_equal (enum machine_mode mode
, rtx op0
, rtx op1
, rtx label
,
2601 do_compare_rtx_and_jump (op0
, op1
, EQ
, unsignedp
, mode
,
2602 NULL_RTX
, NULL_RTX
, label
);
2605 /* Not all case values are encountered equally. This function
2606 uses a heuristic to weight case labels, in cases where that
2607 looks like a reasonable thing to do.
2609 Right now, all we try to guess is text, and we establish the
2612 chars above space: 16
2621 If we find any cases in the switch that are not either -1 or in the range
2622 of valid ASCII characters, or are control characters other than those
2623 commonly used with "\", don't treat this switch scanning text.
2625 Return 1 if these nodes are suitable for cost estimation, otherwise
2629 estimate_case_costs (case_node_ptr node
)
2631 tree min_ascii
= integer_minus_one_node
;
2632 tree max_ascii
= build_int_cst (TREE_TYPE (node
->high
), 127);
2636 /* If we haven't already made the cost table, make it now. Note that the
2637 lower bound of the table is -1, not zero. */
2639 if (! cost_table_initialized
)
2641 cost_table_initialized
= 1;
2643 for (i
= 0; i
< 128; i
++)
2646 COST_TABLE (i
) = 16;
2647 else if (ISPUNCT (i
))
2649 else if (ISCNTRL (i
))
2650 COST_TABLE (i
) = -1;
2653 COST_TABLE (' ') = 8;
2654 COST_TABLE ('\t') = 4;
2655 COST_TABLE ('\0') = 4;
2656 COST_TABLE ('\n') = 2;
2657 COST_TABLE ('\f') = 1;
2658 COST_TABLE ('\v') = 1;
2659 COST_TABLE ('\b') = 1;
2662 /* See if all the case expressions look like text. It is text if the
2663 constant is >= -1 and the highest constant is <= 127. Do all comparisons
2664 as signed arithmetic since we don't want to ever access cost_table with a
2665 value less than -1. Also check that none of the constants in a range
2666 are strange control characters. */
2668 for (n
= node
; n
; n
= n
->right
)
2670 if ((INT_CST_LT (n
->low
, min_ascii
)) || INT_CST_LT (max_ascii
, n
->high
))
2673 for (i
= (HOST_WIDE_INT
) TREE_INT_CST_LOW (n
->low
);
2674 i
<= (HOST_WIDE_INT
) TREE_INT_CST_LOW (n
->high
); i
++)
2675 if (COST_TABLE (i
) < 0)
2679 /* All interesting values are within the range of interesting
2680 ASCII characters. */
2684 /* Take an ordered list of case nodes
2685 and transform them into a near optimal binary tree,
2686 on the assumption that any target code selection value is as
2687 likely as any other.
2689 The transformation is performed by splitting the ordered
2690 list into two equal sections plus a pivot. The parts are
2691 then attached to the pivot as left and right branches. Each
2692 branch is then transformed recursively. */
2695 balance_case_nodes (case_node_ptr
*head
, case_node_ptr parent
)
2708 /* Count the number of entries on branch. Also count the ranges. */
2712 if (!tree_int_cst_equal (np
->low
, np
->high
))
2716 cost
+= COST_TABLE (TREE_INT_CST_LOW (np
->high
));
2720 cost
+= COST_TABLE (TREE_INT_CST_LOW (np
->low
));
2728 /* Split this list if it is long enough for that to help. */
2733 /* Find the place in the list that bisects the list's total cost,
2734 Here I gets half the total cost. */
2739 /* Skip nodes while their cost does not reach that amount. */
2740 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
2741 i
-= COST_TABLE (TREE_INT_CST_LOW ((*npp
)->high
));
2742 i
-= COST_TABLE (TREE_INT_CST_LOW ((*npp
)->low
));
2745 npp
= &(*npp
)->right
;
2750 /* Leave this branch lopsided, but optimize left-hand
2751 side and fill in `parent' fields for right-hand side. */
2753 np
->parent
= parent
;
2754 balance_case_nodes (&np
->left
, np
);
2755 for (; np
->right
; np
= np
->right
)
2756 np
->right
->parent
= np
;
2760 /* If there are just three nodes, split at the middle one. */
2762 npp
= &(*npp
)->right
;
2765 /* Find the place in the list that bisects the list's total cost,
2766 where ranges count as 2.
2767 Here I gets half the total cost. */
2768 i
= (i
+ ranges
+ 1) / 2;
2771 /* Skip nodes while their cost does not reach that amount. */
2772 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
2777 npp
= &(*npp
)->right
;
2782 np
->parent
= parent
;
2785 /* Optimize each of the two split parts. */
2786 balance_case_nodes (&np
->left
, np
);
2787 balance_case_nodes (&np
->right
, np
);
2791 /* Else leave this branch as one level,
2792 but fill in `parent' fields. */
2794 np
->parent
= parent
;
2795 for (; np
->right
; np
= np
->right
)
2796 np
->right
->parent
= np
;
2801 /* Search the parent sections of the case node tree
2802 to see if a test for the lower bound of NODE would be redundant.
2803 INDEX_TYPE is the type of the index expression.
2805 The instructions to generate the case decision tree are
2806 output in the same order as nodes are processed so it is
2807 known that if a parent node checks the range of the current
2808 node minus one that the current node is bounded at its lower
2809 span. Thus the test would be redundant. */
2812 node_has_low_bound (case_node_ptr node
, tree index_type
)
2815 case_node_ptr pnode
;
2817 /* If the lower bound of this node is the lowest value in the index type,
2818 we need not test it. */
2820 if (tree_int_cst_equal (node
->low
, TYPE_MIN_VALUE (index_type
)))
2823 /* If this node has a left branch, the value at the left must be less
2824 than that at this node, so it cannot be bounded at the bottom and
2825 we need not bother testing any further. */
2830 low_minus_one
= fold_build2 (MINUS_EXPR
, TREE_TYPE (node
->low
),
2832 build_int_cst (TREE_TYPE (node
->low
), 1));
2834 /* If the subtraction above overflowed, we can't verify anything.
2835 Otherwise, look for a parent that tests our value - 1. */
2837 if (! tree_int_cst_lt (low_minus_one
, node
->low
))
2840 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
2841 if (tree_int_cst_equal (low_minus_one
, pnode
->high
))
2847 /* Search the parent sections of the case node tree
2848 to see if a test for the upper bound of NODE would be redundant.
2849 INDEX_TYPE is the type of the index expression.
2851 The instructions to generate the case decision tree are
2852 output in the same order as nodes are processed so it is
2853 known that if a parent node checks the range of the current
2854 node plus one that the current node is bounded at its upper
2855 span. Thus the test would be redundant. */
2858 node_has_high_bound (case_node_ptr node
, tree index_type
)
2861 case_node_ptr pnode
;
2863 /* If there is no upper bound, obviously no test is needed. */
2865 if (TYPE_MAX_VALUE (index_type
) == NULL
)
2868 /* If the upper bound of this node is the highest value in the type
2869 of the index expression, we need not test against it. */
2871 if (tree_int_cst_equal (node
->high
, TYPE_MAX_VALUE (index_type
)))
2874 /* If this node has a right branch, the value at the right must be greater
2875 than that at this node, so it cannot be bounded at the top and
2876 we need not bother testing any further. */
2881 high_plus_one
= fold_build2 (PLUS_EXPR
, TREE_TYPE (node
->high
),
2883 build_int_cst (TREE_TYPE (node
->high
), 1));
2885 /* If the addition above overflowed, we can't verify anything.
2886 Otherwise, look for a parent that tests our value + 1. */
2888 if (! tree_int_cst_lt (node
->high
, high_plus_one
))
2891 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
2892 if (tree_int_cst_equal (high_plus_one
, pnode
->low
))
2898 /* Search the parent sections of the
2899 case node tree to see if both tests for the upper and lower
2900 bounds of NODE would be redundant. */
2903 node_is_bounded (case_node_ptr node
, tree index_type
)
2905 return (node_has_low_bound (node
, index_type
)
2906 && node_has_high_bound (node
, index_type
));
2909 /* Emit step-by-step code to select a case for the value of INDEX.
2910 The thus generated decision tree follows the form of the
2911 case-node binary tree NODE, whose nodes represent test conditions.
2912 INDEX_TYPE is the type of the index of the switch.
2914 Care is taken to prune redundant tests from the decision tree
2915 by detecting any boundary conditions already checked by
2916 emitted rtx. (See node_has_high_bound, node_has_low_bound
2917 and node_is_bounded, above.)
2919 Where the test conditions can be shown to be redundant we emit
2920 an unconditional jump to the target code. As a further
2921 optimization, the subordinates of a tree node are examined to
2922 check for bounded nodes. In this case conditional and/or
2923 unconditional jumps as a result of the boundary check for the
2924 current node are arranged to target the subordinates associated
2925 code for out of bound conditions on the current node.
2927 We can assume that when control reaches the code generated here,
2928 the index value has already been compared with the parents
2929 of this node, and determined to be on the same side of each parent
2930 as this node is. Thus, if this node tests for the value 51,
2931 and a parent tested for 52, we don't need to consider
2932 the possibility of a value greater than 51. If another parent
2933 tests for the value 50, then this node need not test anything. */
2936 emit_case_nodes (rtx index
, case_node_ptr node
, rtx default_label
,
2939 /* If INDEX has an unsigned type, we must make unsigned branches. */
2940 int unsignedp
= TYPE_UNSIGNED (index_type
);
2941 enum machine_mode mode
= GET_MODE (index
);
2942 enum machine_mode imode
= TYPE_MODE (index_type
);
2944 /* Handle indices detected as constant during RTL expansion. */
2945 if (mode
== VOIDmode
)
2948 /* See if our parents have already tested everything for us.
2949 If they have, emit an unconditional jump for this node. */
2950 if (node_is_bounded (node
, index_type
))
2951 emit_jump (label_rtx (node
->code_label
));
2953 else if (tree_int_cst_equal (node
->low
, node
->high
))
2955 /* Node is single valued. First see if the index expression matches
2956 this node and then check our children, if any. */
2958 do_jump_if_equal (mode
, index
,
2959 convert_modes (mode
, imode
,
2960 expand_normal (node
->low
),
2962 label_rtx (node
->code_label
), unsignedp
);
2964 if (node
->right
!= 0 && node
->left
!= 0)
2966 /* This node has children on both sides.
2967 Dispatch to one side or the other
2968 by comparing the index value with this node's value.
2969 If one subtree is bounded, check that one first,
2970 so we can avoid real branches in the tree. */
2972 if (node_is_bounded (node
->right
, index_type
))
2974 emit_cmp_and_jump_insns (index
,
2977 expand_normal (node
->high
),
2979 GT
, NULL_RTX
, mode
, unsignedp
,
2980 label_rtx (node
->right
->code_label
));
2981 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
2984 else if (node_is_bounded (node
->left
, index_type
))
2986 emit_cmp_and_jump_insns (index
,
2989 expand_normal (node
->high
),
2991 LT
, NULL_RTX
, mode
, unsignedp
,
2992 label_rtx (node
->left
->code_label
));
2993 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
2996 /* If both children are single-valued cases with no
2997 children, finish up all the work. This way, we can save
2998 one ordered comparison. */
2999 else if (tree_int_cst_equal (node
->right
->low
, node
->right
->high
)
3000 && node
->right
->left
== 0
3001 && node
->right
->right
== 0
3002 && tree_int_cst_equal (node
->left
->low
, node
->left
->high
)
3003 && node
->left
->left
== 0
3004 && node
->left
->right
== 0)
3006 /* Neither node is bounded. First distinguish the two sides;
3007 then emit the code for one side at a time. */
3009 /* See if the value matches what the right hand side
3011 do_jump_if_equal (mode
, index
,
3012 convert_modes (mode
, imode
,
3013 expand_normal (node
->right
->low
),
3015 label_rtx (node
->right
->code_label
),
3018 /* See if the value matches what the left hand side
3020 do_jump_if_equal (mode
, index
,
3021 convert_modes (mode
, imode
,
3022 expand_normal (node
->left
->low
),
3024 label_rtx (node
->left
->code_label
),
3030 /* Neither node is bounded. First distinguish the two sides;
3031 then emit the code for one side at a time. */
3033 tree test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
3035 /* See if the value is on the right. */
3036 emit_cmp_and_jump_insns (index
,
3039 expand_normal (node
->high
),
3041 GT
, NULL_RTX
, mode
, unsignedp
,
3042 label_rtx (test_label
));
3044 /* Value must be on the left.
3045 Handle the left-hand subtree. */
3046 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
3047 /* If left-hand subtree does nothing,
3049 emit_jump (default_label
);
3051 /* Code branches here for the right-hand subtree. */
3052 expand_label (test_label
);
3053 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
3057 else if (node
->right
!= 0 && node
->left
== 0)
3059 /* Here we have a right child but no left so we issue a conditional
3060 branch to default and process the right child.
3062 Omit the conditional branch to default if the right child
3063 does not have any children and is single valued; it would
3064 cost too much space to save so little time. */
3066 if (node
->right
->right
|| node
->right
->left
3067 || !tree_int_cst_equal (node
->right
->low
, node
->right
->high
))
3069 if (!node_has_low_bound (node
, index_type
))
3071 emit_cmp_and_jump_insns (index
,
3074 expand_normal (node
->high
),
3076 LT
, NULL_RTX
, mode
, unsignedp
,
3080 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
3083 /* We cannot process node->right normally
3084 since we haven't ruled out the numbers less than
3085 this node's value. So handle node->right explicitly. */
3086 do_jump_if_equal (mode
, index
,
3089 expand_normal (node
->right
->low
),
3091 label_rtx (node
->right
->code_label
), unsignedp
);
3094 else if (node
->right
== 0 && node
->left
!= 0)
3096 /* Just one subtree, on the left. */
3097 if (node
->left
->left
|| node
->left
->right
3098 || !tree_int_cst_equal (node
->left
->low
, node
->left
->high
))
3100 if (!node_has_high_bound (node
, index_type
))
3102 emit_cmp_and_jump_insns (index
,
3105 expand_normal (node
->high
),
3107 GT
, NULL_RTX
, mode
, unsignedp
,
3111 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
3114 /* We cannot process node->left normally
3115 since we haven't ruled out the numbers less than
3116 this node's value. So handle node->left explicitly. */
3117 do_jump_if_equal (mode
, index
,
3120 expand_normal (node
->left
->low
),
3122 label_rtx (node
->left
->code_label
), unsignedp
);
3127 /* Node is a range. These cases are very similar to those for a single
3128 value, except that we do not start by testing whether this node
3129 is the one to branch to. */
3131 if (node
->right
!= 0 && node
->left
!= 0)
3133 /* Node has subtrees on both sides.
3134 If the right-hand subtree is bounded,
3135 test for it first, since we can go straight there.
3136 Otherwise, we need to make a branch in the control structure,
3137 then handle the two subtrees. */
3138 tree test_label
= 0;
3140 if (node_is_bounded (node
->right
, index_type
))
3141 /* Right hand node is fully bounded so we can eliminate any
3142 testing and branch directly to the target code. */
3143 emit_cmp_and_jump_insns (index
,
3146 expand_normal (node
->high
),
3148 GT
, NULL_RTX
, mode
, unsignedp
,
3149 label_rtx (node
->right
->code_label
));
3152 /* Right hand node requires testing.
3153 Branch to a label where we will handle it later. */
3155 test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
3156 emit_cmp_and_jump_insns (index
,
3159 expand_normal (node
->high
),
3161 GT
, NULL_RTX
, mode
, unsignedp
,
3162 label_rtx (test_label
));
3165 /* Value belongs to this node or to the left-hand subtree. */
3167 emit_cmp_and_jump_insns (index
,
3170 expand_normal (node
->low
),
3172 GE
, NULL_RTX
, mode
, unsignedp
,
3173 label_rtx (node
->code_label
));
3175 /* Handle the left-hand subtree. */
3176 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
3178 /* If right node had to be handled later, do that now. */
3182 /* If the left-hand subtree fell through,
3183 don't let it fall into the right-hand subtree. */
3184 emit_jump (default_label
);
3186 expand_label (test_label
);
3187 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
3191 else if (node
->right
!= 0 && node
->left
== 0)
3193 /* Deal with values to the left of this node,
3194 if they are possible. */
3195 if (!node_has_low_bound (node
, index_type
))
3197 emit_cmp_and_jump_insns (index
,
3200 expand_normal (node
->low
),
3202 LT
, NULL_RTX
, mode
, unsignedp
,
3206 /* Value belongs to this node or to the right-hand subtree. */
3208 emit_cmp_and_jump_insns (index
,
3211 expand_normal (node
->high
),
3213 LE
, NULL_RTX
, mode
, unsignedp
,
3214 label_rtx (node
->code_label
));
3216 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
3219 else if (node
->right
== 0 && node
->left
!= 0)
3221 /* Deal with values to the right of this node,
3222 if they are possible. */
3223 if (!node_has_high_bound (node
, index_type
))
3225 emit_cmp_and_jump_insns (index
,
3228 expand_normal (node
->high
),
3230 GT
, NULL_RTX
, mode
, unsignedp
,
3234 /* Value belongs to this node or to the left-hand subtree. */
3236 emit_cmp_and_jump_insns (index
,
3239 expand_normal (node
->low
),
3241 GE
, NULL_RTX
, mode
, unsignedp
,
3242 label_rtx (node
->code_label
));
3244 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
3249 /* Node has no children so we check low and high bounds to remove
3250 redundant tests. Only one of the bounds can exist,
3251 since otherwise this node is bounded--a case tested already. */
3252 int high_bound
= node_has_high_bound (node
, index_type
);
3253 int low_bound
= node_has_low_bound (node
, index_type
);
3255 if (!high_bound
&& low_bound
)
3257 emit_cmp_and_jump_insns (index
,
3260 expand_normal (node
->high
),
3262 GT
, NULL_RTX
, mode
, unsignedp
,
3266 else if (!low_bound
&& high_bound
)
3268 emit_cmp_and_jump_insns (index
,
3271 expand_normal (node
->low
),
3273 LT
, NULL_RTX
, mode
, unsignedp
,
3276 else if (!low_bound
&& !high_bound
)
3278 /* Widen LOW and HIGH to the same width as INDEX. */
3279 tree type
= lang_hooks
.types
.type_for_mode (mode
, unsignedp
);
3280 tree low
= build1 (CONVERT_EXPR
, type
, node
->low
);
3281 tree high
= build1 (CONVERT_EXPR
, type
, node
->high
);
3282 rtx low_rtx
, new_index
, new_bound
;
3284 /* Instead of doing two branches, emit one unsigned branch for
3285 (index-low) > (high-low). */
3286 low_rtx
= expand_expr (low
, NULL_RTX
, mode
, EXPAND_NORMAL
);
3287 new_index
= expand_simple_binop (mode
, MINUS
, index
, low_rtx
,
3288 NULL_RTX
, unsignedp
,
3290 new_bound
= expand_expr (fold_build2 (MINUS_EXPR
, type
,
3292 NULL_RTX
, mode
, EXPAND_NORMAL
);
3294 emit_cmp_and_jump_insns (new_index
, new_bound
, GT
, NULL_RTX
,
3295 mode
, 1, default_label
);
3298 emit_jump (label_rtx (node
->code_label
));