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
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 (tree string
, int vol
)
267 if (TREE_CODE (string
) == ADDR_EXPR
)
268 string
= TREE_OPERAND (string
, 0);
270 body
= gen_rtx_ASM_INPUT (VOIDmode
,
271 ggc_strdup (TREE_STRING_POINTER (string
)));
273 MEM_VOLATILE_P (body
) = vol
;
278 /* Parse the output constraint pointed to by *CONSTRAINT_P. It is the
279 OPERAND_NUMth output operand, indexed from zero. There are NINPUTS
280 inputs and NOUTPUTS outputs to this extended-asm. Upon return,
281 *ALLOWS_MEM will be TRUE iff the constraint allows the use of a
282 memory operand. Similarly, *ALLOWS_REG will be TRUE iff the
283 constraint allows the use of a register operand. And, *IS_INOUT
284 will be true if the operand is read-write, i.e., if it is used as
285 an input as well as an output. If *CONSTRAINT_P is not in
286 canonical form, it will be made canonical. (Note that `+' will be
287 replaced with `=' as part of this process.)
289 Returns TRUE if all went well; FALSE if an error occurred. */
292 parse_output_constraint (const char **constraint_p
, int operand_num
,
293 int ninputs
, int noutputs
, bool *allows_mem
,
294 bool *allows_reg
, bool *is_inout
)
296 const char *constraint
= *constraint_p
;
299 /* Assume the constraint doesn't allow the use of either a register
304 /* Allow the `=' or `+' to not be at the beginning of the string,
305 since it wasn't explicitly documented that way, and there is a
306 large body of code that puts it last. Swap the character to
307 the front, so as not to uglify any place else. */
308 p
= strchr (constraint
, '=');
310 p
= strchr (constraint
, '+');
312 /* If the string doesn't contain an `=', issue an error
316 error ("output operand constraint lacks %<=%>");
320 /* If the constraint begins with `+', then the operand is both read
321 from and written to. */
322 *is_inout
= (*p
== '+');
324 /* Canonicalize the output constraint so that it begins with `='. */
325 if (p
!= constraint
|| *is_inout
)
328 size_t c_len
= strlen (constraint
);
331 warning (0, "output constraint %qc for operand %d "
332 "is not at the beginning",
335 /* Make a copy of the constraint. */
336 buf
= alloca (c_len
+ 1);
337 strcpy (buf
, constraint
);
338 /* Swap the first character and the `=' or `+'. */
339 buf
[p
- constraint
] = buf
[0];
340 /* Make sure the first character is an `='. (Until we do this,
341 it might be a `+'.) */
343 /* Replace the constraint with the canonicalized string. */
344 *constraint_p
= ggc_alloc_string (buf
, c_len
);
345 constraint
= *constraint_p
;
348 /* Loop through the constraint string. */
349 for (p
= constraint
+ 1; *p
; p
+= CONSTRAINT_LEN (*p
, p
))
354 error ("operand constraint contains incorrectly positioned "
359 if (operand_num
+ 1 == ninputs
+ noutputs
)
361 error ("%<%%%> constraint used with last operand");
366 case 'V': case 'm': case 'o':
370 case '?': case '!': case '*': case '&': case '#':
371 case 'E': case 'F': case 'G': case 'H':
372 case 's': case 'i': case 'n':
373 case 'I': case 'J': case 'K': case 'L': case 'M':
374 case 'N': case 'O': case 'P': case ',':
377 case '0': case '1': case '2': case '3': case '4':
378 case '5': case '6': case '7': case '8': case '9':
380 error ("matching constraint not valid in output operand");
384 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
385 excepting those that expand_call created. So match memory
402 if (REG_CLASS_FROM_CONSTRAINT (*p
, p
) != NO_REGS
)
404 #ifdef EXTRA_CONSTRAINT_STR
405 else if (EXTRA_ADDRESS_CONSTRAINT (*p
, p
))
407 else if (EXTRA_MEMORY_CONSTRAINT (*p
, p
))
411 /* Otherwise we can't assume anything about the nature of
412 the constraint except that it isn't purely registers.
413 Treat it like "g" and hope for the best. */
424 /* Similar, but for input constraints. */
427 parse_input_constraint (const char **constraint_p
, int input_num
,
428 int ninputs
, int noutputs
, int ninout
,
429 const char * const * constraints
,
430 bool *allows_mem
, bool *allows_reg
)
432 const char *constraint
= *constraint_p
;
433 const char *orig_constraint
= constraint
;
434 size_t c_len
= strlen (constraint
);
436 bool saw_match
= false;
438 /* Assume the constraint doesn't allow the use of either
439 a register or memory. */
443 /* Make sure constraint has neither `=', `+', nor '&'. */
445 for (j
= 0; j
< c_len
; j
+= CONSTRAINT_LEN (constraint
[j
], constraint
+j
))
446 switch (constraint
[j
])
448 case '+': case '=': case '&':
449 if (constraint
== orig_constraint
)
451 error ("input operand constraint contains %qc", constraint
[j
]);
457 if (constraint
== orig_constraint
458 && input_num
+ 1 == ninputs
- ninout
)
460 error ("%<%%%> constraint used with last operand");
465 case 'V': case 'm': case 'o':
470 case '?': case '!': case '*': case '#':
471 case 'E': case 'F': case 'G': case 'H':
472 case 's': case 'i': case 'n':
473 case 'I': case 'J': case 'K': case 'L': case 'M':
474 case 'N': case 'O': case 'P': case ',':
477 /* Whether or not a numeric constraint allows a register is
478 decided by the matching constraint, and so there is no need
479 to do anything special with them. We must handle them in
480 the default case, so that we don't unnecessarily force
481 operands to memory. */
482 case '0': case '1': case '2': case '3': case '4':
483 case '5': case '6': case '7': case '8': case '9':
490 match
= strtoul (constraint
+ j
, &end
, 10);
491 if (match
>= (unsigned long) noutputs
)
493 error ("matching constraint references invalid operand number");
497 /* Try and find the real constraint for this dup. Only do this
498 if the matching constraint is the only alternative. */
500 && (j
== 0 || (j
== 1 && constraint
[0] == '%')))
502 constraint
= constraints
[match
];
503 *constraint_p
= constraint
;
504 c_len
= strlen (constraint
);
506 /* ??? At the end of the loop, we will skip the first part of
507 the matched constraint. This assumes not only that the
508 other constraint is an output constraint, but also that
509 the '=' or '+' come first. */
513 j
= end
- constraint
;
514 /* Anticipate increment at end of loop. */
529 if (! ISALPHA (constraint
[j
]))
531 error ("invalid punctuation %qc in constraint", constraint
[j
]);
534 if (REG_CLASS_FROM_CONSTRAINT (constraint
[j
], constraint
+ j
)
537 #ifdef EXTRA_CONSTRAINT_STR
538 else if (EXTRA_ADDRESS_CONSTRAINT (constraint
[j
], constraint
+ j
))
540 else if (EXTRA_MEMORY_CONSTRAINT (constraint
[j
], constraint
+ j
))
544 /* Otherwise we can't assume anything about the nature of
545 the constraint except that it isn't purely registers.
546 Treat it like "g" and hope for the best. */
554 if (saw_match
&& !*allows_reg
)
555 warning (0, "matching constraint does not allow a register");
560 /* Return DECL iff there's an overlap between *REGS and DECL, where DECL
561 can be an asm-declared register. Called via walk_tree. */
564 decl_overlaps_hard_reg_set_p (tree
*declp
, int *walk_subtrees ATTRIBUTE_UNUSED
,
568 const HARD_REG_SET
*regs
= data
;
570 if (TREE_CODE (decl
) == VAR_DECL
)
572 if (DECL_HARD_REGISTER (decl
)
573 && REG_P (DECL_RTL (decl
))
574 && REGNO (DECL_RTL (decl
)) < FIRST_PSEUDO_REGISTER
)
576 rtx reg
= DECL_RTL (decl
);
579 for (regno
= REGNO (reg
);
581 + hard_regno_nregs
[REGNO (reg
)][GET_MODE (reg
)]);
583 if (TEST_HARD_REG_BIT (*regs
, regno
))
588 else if (TYPE_P (decl
) || TREE_CODE (decl
) == PARM_DECL
)
593 /* If there is an overlap between *REGS and DECL, return the first overlap
596 tree_overlaps_hard_reg_set (tree decl
, HARD_REG_SET
*regs
)
598 return walk_tree (&decl
, decl_overlaps_hard_reg_set_p
, regs
, NULL
);
601 /* Check for overlap between registers marked in CLOBBERED_REGS and
602 anything inappropriate in T. Emit error and return the register
603 variable definition for error, NULL_TREE for ok. */
606 tree_conflicts_with_clobbers_p (tree t
, HARD_REG_SET
*clobbered_regs
)
608 /* Conflicts between asm-declared register variables and the clobber
609 list are not allowed. */
610 tree overlap
= tree_overlaps_hard_reg_set (t
, clobbered_regs
);
614 error ("asm-specifier for variable %qs conflicts with asm clobber list",
615 IDENTIFIER_POINTER (DECL_NAME (overlap
)));
617 /* Reset registerness to stop multiple errors emitted for a single
619 DECL_REGISTER (overlap
) = 0;
626 /* Generate RTL for an asm statement with arguments.
627 STRING is the instruction template.
628 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
629 Each output or input has an expression in the TREE_VALUE and
630 and a tree list in TREE_PURPOSE which in turn contains a constraint
631 name in TREE_VALUE (or NULL_TREE) and a constraint string
633 CLOBBERS is a list of STRING_CST nodes each naming a hard register
634 that is clobbered by this insn.
636 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
637 Some elements of OUTPUTS may be replaced with trees representing temporary
638 values. The caller should copy those temporary values to the originally
641 VOL nonzero means the insn is volatile; don't optimize it. */
644 expand_asm_operands (tree string
, tree outputs
, tree inputs
,
645 tree clobbers
, int vol
, location_t locus
)
647 rtvec argvec
, constraintvec
;
649 int ninputs
= list_length (inputs
);
650 int noutputs
= list_length (outputs
);
653 HARD_REG_SET clobbered_regs
;
654 int clobber_conflict_found
= 0;
658 /* Vector of RTX's of evaluated output operands. */
659 rtx
*output_rtx
= alloca (noutputs
* sizeof (rtx
));
660 int *inout_opnum
= alloca (noutputs
* sizeof (int));
661 rtx
*real_output_rtx
= alloca (noutputs
* sizeof (rtx
));
662 enum machine_mode
*inout_mode
663 = alloca (noutputs
* sizeof (enum machine_mode
));
664 const char **constraints
665 = alloca ((noutputs
+ ninputs
) * sizeof (const char *));
666 int old_generating_concat_p
= generating_concat_p
;
668 /* An ASM with no outputs needs to be treated as volatile, for now. */
672 if (! check_operand_nalternatives (outputs
, inputs
))
675 string
= resolve_asm_operand_names (string
, outputs
, inputs
);
677 /* Collect constraints. */
679 for (t
= outputs
; t
; t
= TREE_CHAIN (t
), i
++)
680 constraints
[i
] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t
)));
681 for (t
= inputs
; t
; t
= TREE_CHAIN (t
), i
++)
682 constraints
[i
] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t
)));
684 /* Sometimes we wish to automatically clobber registers across an asm.
685 Case in point is when the i386 backend moved from cc0 to a hard reg --
686 maintaining source-level compatibility means automatically clobbering
687 the flags register. */
688 clobbers
= targetm
.md_asm_clobbers (outputs
, inputs
, clobbers
);
690 /* Count the number of meaningful clobbered registers, ignoring what
691 we would ignore later. */
693 CLEAR_HARD_REG_SET (clobbered_regs
);
694 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
698 if (TREE_VALUE (tail
) == error_mark_node
)
700 regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
702 i
= decode_reg_name (regname
);
703 if (i
>= 0 || i
== -4)
706 error ("unknown register name %qs in %<asm%>", regname
);
708 /* Mark clobbered registers. */
711 /* Clobbering the PIC register is an error. */
712 if (i
== (int) PIC_OFFSET_TABLE_REGNUM
)
714 error ("PIC register %qs clobbered in %<asm%>", regname
);
718 SET_HARD_REG_BIT (clobbered_regs
, i
);
722 /* First pass over inputs and outputs checks validity and sets
723 mark_addressable if needed. */
726 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
728 tree val
= TREE_VALUE (tail
);
729 tree type
= TREE_TYPE (val
);
730 const char *constraint
;
735 /* If there's an erroneous arg, emit no insn. */
736 if (type
== error_mark_node
)
739 /* Try to parse the output constraint. If that fails, there's
740 no point in going further. */
741 constraint
= constraints
[i
];
742 if (!parse_output_constraint (&constraint
, i
, ninputs
, noutputs
,
743 &allows_mem
, &allows_reg
, &is_inout
))
750 && REG_P (DECL_RTL (val
))
751 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
))))
752 lang_hooks
.mark_addressable (val
);
759 if (ninputs
+ noutputs
> MAX_RECOG_OPERANDS
)
761 error ("more than %d operands in %<asm%>", MAX_RECOG_OPERANDS
);
765 for (i
= 0, tail
= inputs
; tail
; i
++, tail
= TREE_CHAIN (tail
))
767 bool allows_reg
, allows_mem
;
768 const char *constraint
;
770 /* If there's an erroneous arg, emit no insn, because the ASM_INPUT
771 would get VOIDmode and that could cause a crash in reload. */
772 if (TREE_TYPE (TREE_VALUE (tail
)) == error_mark_node
)
775 constraint
= constraints
[i
+ noutputs
];
776 if (! parse_input_constraint (&constraint
, i
, ninputs
, noutputs
, ninout
,
777 constraints
, &allows_mem
, &allows_reg
))
780 if (! allows_reg
&& allows_mem
)
781 lang_hooks
.mark_addressable (TREE_VALUE (tail
));
784 /* Second pass evaluates arguments. */
787 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
789 tree val
= TREE_VALUE (tail
);
790 tree type
= TREE_TYPE (val
);
797 ok
= parse_output_constraint (&constraints
[i
], i
, ninputs
,
798 noutputs
, &allows_mem
, &allows_reg
,
802 /* If an output operand is not a decl or indirect ref and our constraint
803 allows a register, make a temporary to act as an intermediate.
804 Make the asm insn write into that, then our caller will copy it to
805 the real output operand. Likewise for promoted variables. */
807 generating_concat_p
= 0;
809 real_output_rtx
[i
] = NULL_RTX
;
810 if ((TREE_CODE (val
) == INDIRECT_REF
813 && (allows_mem
|| REG_P (DECL_RTL (val
)))
814 && ! (REG_P (DECL_RTL (val
))
815 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
)))
819 op
= expand_expr (val
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
821 op
= validize_mem (op
);
823 if (! allows_reg
&& !MEM_P (op
))
824 error ("output number %d not directly addressable", i
);
825 if ((! allows_mem
&& MEM_P (op
))
826 || GET_CODE (op
) == CONCAT
)
828 real_output_rtx
[i
] = op
;
829 op
= gen_reg_rtx (GET_MODE (op
));
831 emit_move_insn (op
, real_output_rtx
[i
]);
836 op
= assign_temp (type
, 0, 0, 1);
837 op
= validize_mem (op
);
838 TREE_VALUE (tail
) = make_tree (type
, op
);
842 generating_concat_p
= old_generating_concat_p
;
846 inout_mode
[ninout
] = TYPE_MODE (type
);
847 inout_opnum
[ninout
++] = i
;
850 if (tree_conflicts_with_clobbers_p (val
, &clobbered_regs
))
851 clobber_conflict_found
= 1;
854 /* Make vectors for the expression-rtx, constraint strings,
855 and named operands. */
857 argvec
= rtvec_alloc (ninputs
);
858 constraintvec
= rtvec_alloc (ninputs
);
860 body
= gen_rtx_ASM_OPERANDS ((noutputs
== 0 ? VOIDmode
861 : GET_MODE (output_rtx
[0])),
862 ggc_strdup (TREE_STRING_POINTER (string
)),
863 empty_string
, 0, argvec
, constraintvec
,
866 MEM_VOLATILE_P (body
) = vol
;
868 /* Eval the inputs and put them into ARGVEC.
869 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
871 for (i
= 0, tail
= inputs
; tail
; tail
= TREE_CHAIN (tail
), ++i
)
873 bool allows_reg
, allows_mem
;
874 const char *constraint
;
879 constraint
= constraints
[i
+ noutputs
];
880 ok
= parse_input_constraint (&constraint
, i
, ninputs
, noutputs
, ninout
,
881 constraints
, &allows_mem
, &allows_reg
);
884 generating_concat_p
= 0;
886 val
= TREE_VALUE (tail
);
887 type
= TREE_TYPE (val
);
888 /* EXPAND_INITIALIZER will not generate code for valid initializer
889 constants, but will still generate code for other types of operand.
890 This is the behavior we want for constant constraints. */
891 op
= expand_expr (val
, NULL_RTX
, VOIDmode
,
892 allows_reg
? EXPAND_NORMAL
893 : allows_mem
? EXPAND_MEMORY
894 : EXPAND_INITIALIZER
);
896 /* Never pass a CONCAT to an ASM. */
897 if (GET_CODE (op
) == CONCAT
)
898 op
= force_reg (GET_MODE (op
), op
);
900 op
= validize_mem (op
);
902 if (asm_operand_ok (op
, constraint
) <= 0)
904 if (allows_reg
&& TYPE_MODE (type
) != BLKmode
)
905 op
= force_reg (TYPE_MODE (type
), op
);
906 else if (!allows_mem
)
907 warning (0, "asm operand %d probably doesn%'t match constraints",
911 /* We won't recognize either volatile memory or memory
912 with a queued address as available a memory_operand
913 at this point. Ignore it: clearly this *is* a memory. */
917 warning (0, "use of memory input without lvalue in "
918 "asm operand %d is deprecated", i
+ noutputs
);
922 rtx mem
= force_const_mem (TYPE_MODE (type
), op
);
924 op
= validize_mem (mem
);
926 op
= force_reg (TYPE_MODE (type
), op
);
929 || GET_CODE (op
) == SUBREG
930 || GET_CODE (op
) == CONCAT
)
932 tree qual_type
= build_qualified_type (type
,
935 rtx memloc
= assign_temp (qual_type
, 1, 1, 1);
936 memloc
= validize_mem (memloc
);
937 emit_move_insn (memloc
, op
);
943 generating_concat_p
= old_generating_concat_p
;
944 ASM_OPERANDS_INPUT (body
, i
) = op
;
946 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body
, i
)
947 = gen_rtx_ASM_INPUT (TYPE_MODE (type
),
948 ggc_strdup (constraints
[i
+ noutputs
]));
950 if (tree_conflicts_with_clobbers_p (val
, &clobbered_regs
))
951 clobber_conflict_found
= 1;
954 /* Protect all the operands from the queue now that they have all been
957 generating_concat_p
= 0;
959 /* For in-out operands, copy output rtx to input rtx. */
960 for (i
= 0; i
< ninout
; i
++)
962 int j
= inout_opnum
[i
];
965 ASM_OPERANDS_INPUT (body
, ninputs
- ninout
+ i
)
968 sprintf (buffer
, "%d", j
);
969 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body
, ninputs
- ninout
+ i
)
970 = gen_rtx_ASM_INPUT (inout_mode
[i
], ggc_strdup (buffer
));
973 generating_concat_p
= old_generating_concat_p
;
975 /* Now, for each output, construct an rtx
976 (set OUTPUT (asm_operands INSN OUTPUTCONSTRAINT OUTPUTNUMBER
977 ARGVEC CONSTRAINTS OPNAMES))
978 If there is more than one, put them inside a PARALLEL. */
980 if (noutputs
== 1 && nclobbers
== 0)
982 ASM_OPERANDS_OUTPUT_CONSTRAINT (body
) = ggc_strdup (constraints
[0]);
983 emit_insn (gen_rtx_SET (VOIDmode
, output_rtx
[0], body
));
986 else if (noutputs
== 0 && nclobbers
== 0)
988 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1000 body
= gen_rtx_PARALLEL (VOIDmode
, rtvec_alloc (num
+ nclobbers
));
1002 /* For each output operand, store a SET. */
1003 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1005 XVECEXP (body
, 0, i
)
1006 = gen_rtx_SET (VOIDmode
,
1008 gen_rtx_ASM_OPERANDS
1009 (GET_MODE (output_rtx
[i
]),
1010 ggc_strdup (TREE_STRING_POINTER (string
)),
1011 ggc_strdup (constraints
[i
]),
1012 i
, argvec
, constraintvec
, locus
));
1014 MEM_VOLATILE_P (SET_SRC (XVECEXP (body
, 0, i
))) = vol
;
1017 /* If there are no outputs (but there are some clobbers)
1018 store the bare ASM_OPERANDS into the PARALLEL. */
1021 XVECEXP (body
, 0, i
++) = obody
;
1023 /* Store (clobber REG) for each clobbered register specified. */
1025 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1027 const char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1028 int j
= decode_reg_name (regname
);
1033 if (j
== -3) /* `cc', which is not a register */
1036 if (j
== -4) /* `memory', don't cache memory across asm */
1038 XVECEXP (body
, 0, i
++)
1039 = gen_rtx_CLOBBER (VOIDmode
,
1042 gen_rtx_SCRATCH (VOIDmode
)));
1046 /* Ignore unknown register, error already signaled. */
1050 /* Use QImode since that's guaranteed to clobber just one reg. */
1051 clobbered_reg
= gen_rtx_REG (QImode
, j
);
1053 /* Do sanity check for overlap between clobbers and respectively
1054 input and outputs that hasn't been handled. Such overlap
1055 should have been detected and reported above. */
1056 if (!clobber_conflict_found
)
1060 /* We test the old body (obody) contents to avoid tripping
1061 over the under-construction body. */
1062 for (opno
= 0; opno
< noutputs
; opno
++)
1063 if (reg_overlap_mentioned_p (clobbered_reg
, output_rtx
[opno
]))
1064 internal_error ("asm clobber conflict with output operand");
1066 for (opno
= 0; opno
< ninputs
- ninout
; opno
++)
1067 if (reg_overlap_mentioned_p (clobbered_reg
,
1068 ASM_OPERANDS_INPUT (obody
, opno
)))
1069 internal_error ("asm clobber conflict with input operand");
1072 XVECEXP (body
, 0, i
++)
1073 = gen_rtx_CLOBBER (VOIDmode
, clobbered_reg
);
1079 /* For any outputs that needed reloading into registers, spill them
1080 back to where they belong. */
1081 for (i
= 0; i
< noutputs
; ++i
)
1082 if (real_output_rtx
[i
])
1083 emit_move_insn (real_output_rtx
[i
], output_rtx
[i
]);
1089 expand_asm_expr (tree exp
)
1095 if (ASM_INPUT_P (exp
))
1097 expand_asm (ASM_STRING (exp
), ASM_VOLATILE_P (exp
));
1101 outputs
= ASM_OUTPUTS (exp
);
1102 noutputs
= list_length (outputs
);
1103 /* o[I] is the place that output number I should be written. */
1104 o
= (tree
*) alloca (noutputs
* sizeof (tree
));
1106 /* Record the contents of OUTPUTS before it is modified. */
1107 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1108 o
[i
] = TREE_VALUE (tail
);
1110 /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
1111 OUTPUTS some trees for where the values were actually stored. */
1112 expand_asm_operands (ASM_STRING (exp
), outputs
, ASM_INPUTS (exp
),
1113 ASM_CLOBBERS (exp
), ASM_VOLATILE_P (exp
),
1116 /* Copy all the intermediate outputs into the specified outputs. */
1117 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1119 if (o
[i
] != TREE_VALUE (tail
))
1121 expand_assignment (o
[i
], TREE_VALUE (tail
));
1124 /* Restore the original value so that it's correct the next
1125 time we expand this function. */
1126 TREE_VALUE (tail
) = o
[i
];
1131 /* A subroutine of expand_asm_operands. Check that all operands have
1132 the same number of alternatives. Return true if so. */
1135 check_operand_nalternatives (tree outputs
, tree inputs
)
1137 if (outputs
|| inputs
)
1139 tree tmp
= TREE_PURPOSE (outputs
? outputs
: inputs
);
1141 = n_occurrences (',', TREE_STRING_POINTER (TREE_VALUE (tmp
)));
1144 if (nalternatives
+ 1 > MAX_RECOG_ALTERNATIVES
)
1146 error ("too many alternatives in %<asm%>");
1153 const char *constraint
1154 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tmp
)));
1156 if (n_occurrences (',', constraint
) != nalternatives
)
1158 error ("operand constraints for %<asm%> differ "
1159 "in number of alternatives");
1163 if (TREE_CHAIN (tmp
))
1164 tmp
= TREE_CHAIN (tmp
);
1166 tmp
= next
, next
= 0;
1173 /* A subroutine of expand_asm_operands. Check that all operand names
1174 are unique. Return true if so. We rely on the fact that these names
1175 are identifiers, and so have been canonicalized by get_identifier,
1176 so all we need are pointer comparisons. */
1179 check_unique_operand_names (tree outputs
, tree inputs
)
1183 for (i
= outputs
; i
; i
= TREE_CHAIN (i
))
1185 tree i_name
= TREE_PURPOSE (TREE_PURPOSE (i
));
1189 for (j
= TREE_CHAIN (i
); j
; j
= TREE_CHAIN (j
))
1190 if (simple_cst_equal (i_name
, TREE_PURPOSE (TREE_PURPOSE (j
))))
1194 for (i
= inputs
; i
; i
= TREE_CHAIN (i
))
1196 tree i_name
= TREE_PURPOSE (TREE_PURPOSE (i
));
1200 for (j
= TREE_CHAIN (i
); j
; j
= TREE_CHAIN (j
))
1201 if (simple_cst_equal (i_name
, TREE_PURPOSE (TREE_PURPOSE (j
))))
1203 for (j
= outputs
; j
; j
= TREE_CHAIN (j
))
1204 if (simple_cst_equal (i_name
, TREE_PURPOSE (TREE_PURPOSE (j
))))
1211 error ("duplicate asm operand name %qs",
1212 TREE_STRING_POINTER (TREE_PURPOSE (TREE_PURPOSE (i
))));
1216 /* A subroutine of expand_asm_operands. Resolve the names of the operands
1217 in *POUTPUTS and *PINPUTS to numbers, and replace the name expansions in
1218 STRING and in the constraints to those numbers. */
1221 resolve_asm_operand_names (tree string
, tree outputs
, tree inputs
)
1228 check_unique_operand_names (outputs
, inputs
);
1230 /* Substitute [<name>] in input constraint strings. There should be no
1231 named operands in output constraints. */
1232 for (t
= inputs
; t
; t
= TREE_CHAIN (t
))
1234 c
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t
)));
1235 if (strchr (c
, '[') != NULL
)
1237 p
= buffer
= xstrdup (c
);
1238 while ((p
= strchr (p
, '[')) != NULL
)
1239 p
= resolve_operand_name_1 (p
, outputs
, inputs
);
1240 TREE_VALUE (TREE_PURPOSE (t
))
1241 = build_string (strlen (buffer
), buffer
);
1246 /* Now check for any needed substitutions in the template. */
1247 c
= TREE_STRING_POINTER (string
);
1248 while ((c
= strchr (c
, '%')) != NULL
)
1252 else if (ISALPHA (c
[1]) && c
[2] == '[')
1263 /* OK, we need to make a copy so we can perform the substitutions.
1264 Assume that we will not need extra space--we get to remove '['
1265 and ']', which means we cannot have a problem until we have more
1266 than 999 operands. */
1267 buffer
= xstrdup (TREE_STRING_POINTER (string
));
1268 p
= buffer
+ (c
- TREE_STRING_POINTER (string
));
1270 while ((p
= strchr (p
, '%')) != NULL
)
1274 else if (ISALPHA (p
[1]) && p
[2] == '[')
1282 p
= resolve_operand_name_1 (p
, outputs
, inputs
);
1285 string
= build_string (strlen (buffer
), buffer
);
1292 /* A subroutine of resolve_operand_names. P points to the '[' for a
1293 potential named operand of the form [<name>]. In place, replace
1294 the name and brackets with a number. Return a pointer to the
1295 balance of the string after substitution. */
1298 resolve_operand_name_1 (char *p
, tree outputs
, tree inputs
)
1305 /* Collect the operand name. */
1306 q
= strchr (p
, ']');
1309 error ("missing close brace for named operand");
1310 return strchr (p
, '\0');
1314 /* Resolve the name to a number. */
1315 for (op
= 0, t
= outputs
; t
; t
= TREE_CHAIN (t
), op
++)
1317 tree name
= TREE_PURPOSE (TREE_PURPOSE (t
));
1320 const char *c
= TREE_STRING_POINTER (name
);
1321 if (strncmp (c
, p
+ 1, len
) == 0 && c
[len
] == '\0')
1325 for (t
= inputs
; t
; t
= TREE_CHAIN (t
), op
++)
1327 tree name
= TREE_PURPOSE (TREE_PURPOSE (t
));
1330 const char *c
= TREE_STRING_POINTER (name
);
1331 if (strncmp (c
, p
+ 1, len
) == 0 && c
[len
] == '\0')
1337 error ("undefined named operand %qs", p
+ 1);
1341 /* Replace the name with the number. Unfortunately, not all libraries
1342 get the return value of sprintf correct, so search for the end of the
1343 generated string by hand. */
1344 sprintf (p
, "%d", op
);
1345 p
= strchr (p
, '\0');
1347 /* Verify the no extra buffer space assumption. */
1348 gcc_assert (p
<= q
);
1350 /* Shift the rest of the buffer down to fill the gap. */
1351 memmove (p
, q
+ 1, strlen (q
+ 1) + 1);
1356 /* Generate RTL to evaluate the expression EXP. */
1359 expand_expr_stmt (tree exp
)
1364 value
= expand_expr (exp
, const0_rtx
, VOIDmode
, 0);
1365 if (GIMPLE_TUPLE_P (exp
))
1366 type
= void_type_node
;
1368 type
= TREE_TYPE (exp
);
1370 /* If all we do is reference a volatile value in memory,
1371 copy it to a register to be sure it is actually touched. */
1372 if (value
&& MEM_P (value
) && TREE_THIS_VOLATILE (exp
))
1374 if (TYPE_MODE (type
) == VOIDmode
)
1376 else if (TYPE_MODE (type
) != BLKmode
)
1377 value
= copy_to_reg (value
);
1380 rtx lab
= gen_label_rtx ();
1382 /* Compare the value with itself to reference it. */
1383 emit_cmp_and_jump_insns (value
, value
, EQ
,
1384 expand_normal (TYPE_SIZE (type
)),
1390 /* Free any temporaries used to evaluate this expression. */
1394 /* Warn if EXP contains any computations whose results are not used.
1395 Return 1 if a warning is printed; 0 otherwise. LOCUS is the
1396 (potential) location of the expression. */
1399 warn_if_unused_value (tree exp
, location_t locus
)
1402 if (TREE_USED (exp
) || TREE_NO_WARNING (exp
))
1405 /* Don't warn about void constructs. This includes casting to void,
1406 void function calls, and statement expressions with a final cast
1408 if (VOID_TYPE_P (TREE_TYPE (exp
)))
1411 if (EXPR_HAS_LOCATION (exp
))
1412 locus
= EXPR_LOCATION (exp
);
1414 switch (TREE_CODE (exp
))
1416 case PREINCREMENT_EXPR
:
1417 case POSTINCREMENT_EXPR
:
1418 case PREDECREMENT_EXPR
:
1419 case POSTDECREMENT_EXPR
:
1421 case GIMPLE_MODIFY_STMT
:
1425 case TRY_CATCH_EXPR
:
1426 case WITH_CLEANUP_EXPR
:
1432 /* For a binding, warn if no side effect within it. */
1433 exp
= BIND_EXPR_BODY (exp
);
1437 exp
= TREE_OPERAND (exp
, 0);
1440 case TRUTH_ORIF_EXPR
:
1441 case TRUTH_ANDIF_EXPR
:
1442 /* In && or ||, warn if 2nd operand has no side effect. */
1443 exp
= TREE_OPERAND (exp
, 1);
1447 if (warn_if_unused_value (TREE_OPERAND (exp
, 0), locus
))
1449 /* Let people do `(foo (), 0)' without a warning. */
1450 if (TREE_CONSTANT (TREE_OPERAND (exp
, 1)))
1452 exp
= TREE_OPERAND (exp
, 1);
1456 /* If this is an expression with side effects, don't warn; this
1457 case commonly appears in macro expansions. */
1458 if (TREE_SIDE_EFFECTS (exp
))
1463 /* Don't warn about automatic dereferencing of references, since
1464 the user cannot control it. */
1465 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp
, 0))) == REFERENCE_TYPE
)
1467 exp
= TREE_OPERAND (exp
, 0);
1473 /* Referencing a volatile value is a side effect, so don't warn. */
1474 if ((DECL_P (exp
) || REFERENCE_CLASS_P (exp
))
1475 && TREE_THIS_VOLATILE (exp
))
1478 /* If this is an expression which has no operands, there is no value
1479 to be unused. There are no such language-independent codes,
1480 but front ends may define such. */
1481 if (EXPRESSION_CLASS_P (exp
) && TREE_OPERAND_LENGTH (exp
) == 0)
1485 warning (0, "%Hvalue computed is not used", &locus
);
1491 /* Generate RTL to return from the current function, with no value.
1492 (That is, we do not do anything about returning any value.) */
1495 expand_null_return (void)
1497 /* If this function was declared to return a value, but we
1498 didn't, clobber the return registers so that they are not
1499 propagated live to the rest of the function. */
1500 clobber_return_register ();
1502 expand_null_return_1 ();
1505 /* Generate RTL to return directly from the current function.
1506 (That is, we bypass any return value.) */
1509 expand_naked_return (void)
1513 clear_pending_stack_adjust ();
1514 do_pending_stack_adjust ();
1516 end_label
= naked_return_label
;
1518 end_label
= naked_return_label
= gen_label_rtx ();
1520 emit_jump (end_label
);
1523 /* Generate RTL to return from the current function, with value VAL. */
1526 expand_value_return (rtx val
)
1528 /* Copy the value to the return location
1529 unless it's already there. */
1531 rtx return_reg
= DECL_RTL (DECL_RESULT (current_function_decl
));
1532 if (return_reg
!= val
)
1534 tree type
= TREE_TYPE (DECL_RESULT (current_function_decl
));
1535 if (targetm
.calls
.promote_function_return (TREE_TYPE (current_function_decl
)))
1537 int unsignedp
= TYPE_UNSIGNED (type
);
1538 enum machine_mode old_mode
1539 = DECL_MODE (DECL_RESULT (current_function_decl
));
1540 enum machine_mode mode
1541 = promote_mode (type
, old_mode
, &unsignedp
, 1);
1543 if (mode
!= old_mode
)
1544 val
= convert_modes (mode
, old_mode
, val
, unsignedp
);
1546 if (GET_CODE (return_reg
) == PARALLEL
)
1547 emit_group_load (return_reg
, val
, type
, int_size_in_bytes (type
));
1549 emit_move_insn (return_reg
, val
);
1552 expand_null_return_1 ();
1555 /* Output a return with no value. */
1558 expand_null_return_1 (void)
1560 clear_pending_stack_adjust ();
1561 do_pending_stack_adjust ();
1562 emit_jump (return_label
);
1565 /* Generate RTL to evaluate the expression RETVAL and return it
1566 from the current function. */
1569 expand_return (tree retval
)
1575 /* If function wants no value, give it none. */
1576 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl
))) == VOID_TYPE
)
1578 expand_normal (retval
);
1579 expand_null_return ();
1583 if (retval
== error_mark_node
)
1585 /* Treat this like a return of no value from a function that
1587 expand_null_return ();
1590 else if ((TREE_CODE (retval
) == GIMPLE_MODIFY_STMT
1591 || TREE_CODE (retval
) == INIT_EXPR
)
1592 && TREE_CODE (GENERIC_TREE_OPERAND (retval
, 0)) == RESULT_DECL
)
1593 retval_rhs
= GENERIC_TREE_OPERAND (retval
, 1);
1595 retval_rhs
= retval
;
1597 result_rtl
= DECL_RTL (DECL_RESULT (current_function_decl
));
1599 /* If we are returning the RESULT_DECL, then the value has already
1600 been stored into it, so we don't have to do anything special. */
1601 if (TREE_CODE (retval_rhs
) == RESULT_DECL
)
1602 expand_value_return (result_rtl
);
1604 /* If the result is an aggregate that is being returned in one (or more)
1605 registers, load the registers here. The compiler currently can't handle
1606 copying a BLKmode value into registers. We could put this code in a
1607 more general area (for use by everyone instead of just function
1608 call/return), but until this feature is generally usable it is kept here
1609 (and in expand_call). */
1611 else if (retval_rhs
!= 0
1612 && TYPE_MODE (GENERIC_TREE_TYPE (retval_rhs
)) == BLKmode
1613 && REG_P (result_rtl
))
1616 unsigned HOST_WIDE_INT bitpos
, xbitpos
;
1617 unsigned HOST_WIDE_INT padding_correction
= 0;
1618 unsigned HOST_WIDE_INT bytes
1619 = int_size_in_bytes (TREE_TYPE (retval_rhs
));
1620 int n_regs
= (bytes
+ UNITS_PER_WORD
- 1) / UNITS_PER_WORD
;
1621 unsigned int bitsize
1622 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs
)), BITS_PER_WORD
);
1623 rtx
*result_pseudos
= alloca (sizeof (rtx
) * n_regs
);
1624 rtx result_reg
, src
= NULL_RTX
, dst
= NULL_RTX
;
1625 rtx result_val
= expand_normal (retval_rhs
);
1626 enum machine_mode tmpmode
, result_reg_mode
;
1630 expand_null_return ();
1634 /* If the structure doesn't take up a whole number of words, see
1635 whether the register value should be padded on the left or on
1636 the right. Set PADDING_CORRECTION to the number of padding
1637 bits needed on the left side.
1639 In most ABIs, the structure will be returned at the least end of
1640 the register, which translates to right padding on little-endian
1641 targets and left padding on big-endian targets. The opposite
1642 holds if the structure is returned at the most significant
1643 end of the register. */
1644 if (bytes
% UNITS_PER_WORD
!= 0
1645 && (targetm
.calls
.return_in_msb (TREE_TYPE (retval_rhs
))
1647 : BYTES_BIG_ENDIAN
))
1648 padding_correction
= (BITS_PER_WORD
- ((bytes
% UNITS_PER_WORD
)
1651 /* Copy the structure BITSIZE bits at a time. */
1652 for (bitpos
= 0, xbitpos
= padding_correction
;
1653 bitpos
< bytes
* BITS_PER_UNIT
;
1654 bitpos
+= bitsize
, xbitpos
+= bitsize
)
1656 /* We need a new destination pseudo each time xbitpos is
1657 on a word boundary and when xbitpos == padding_correction
1658 (the first time through). */
1659 if (xbitpos
% BITS_PER_WORD
== 0
1660 || xbitpos
== padding_correction
)
1662 /* Generate an appropriate register. */
1663 dst
= gen_reg_rtx (word_mode
);
1664 result_pseudos
[xbitpos
/ BITS_PER_WORD
] = dst
;
1666 /* Clear the destination before we move anything into it. */
1667 emit_move_insn (dst
, CONST0_RTX (GET_MODE (dst
)));
1670 /* We need a new source operand each time bitpos is on a word
1672 if (bitpos
% BITS_PER_WORD
== 0)
1673 src
= operand_subword_force (result_val
,
1674 bitpos
/ BITS_PER_WORD
,
1677 /* Use bitpos for the source extraction (left justified) and
1678 xbitpos for the destination store (right justified). */
1679 store_bit_field (dst
, bitsize
, xbitpos
% BITS_PER_WORD
, word_mode
,
1680 extract_bit_field (src
, bitsize
,
1681 bitpos
% BITS_PER_WORD
, 1,
1682 NULL_RTX
, word_mode
, word_mode
));
1685 tmpmode
= GET_MODE (result_rtl
);
1686 if (tmpmode
== BLKmode
)
1688 /* Find the smallest integer mode large enough to hold the
1689 entire structure and use that mode instead of BLKmode
1690 on the USE insn for the return register. */
1691 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
1692 tmpmode
!= VOIDmode
;
1693 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
1694 /* Have we found a large enough mode? */
1695 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
1698 /* A suitable mode should have been found. */
1699 gcc_assert (tmpmode
!= VOIDmode
);
1701 PUT_MODE (result_rtl
, tmpmode
);
1704 if (GET_MODE_SIZE (tmpmode
) < GET_MODE_SIZE (word_mode
))
1705 result_reg_mode
= word_mode
;
1707 result_reg_mode
= tmpmode
;
1708 result_reg
= gen_reg_rtx (result_reg_mode
);
1710 for (i
= 0; i
< n_regs
; i
++)
1711 emit_move_insn (operand_subword (result_reg
, i
, 0, result_reg_mode
),
1714 if (tmpmode
!= result_reg_mode
)
1715 result_reg
= gen_lowpart (tmpmode
, result_reg
);
1717 expand_value_return (result_reg
);
1719 else if (retval_rhs
!= 0
1720 && !VOID_TYPE_P (TREE_TYPE (retval_rhs
))
1721 && (REG_P (result_rtl
)
1722 || (GET_CODE (result_rtl
) == PARALLEL
)))
1724 /* Calculate the return value into a temporary (usually a pseudo
1726 tree ot
= TREE_TYPE (DECL_RESULT (current_function_decl
));
1727 tree nt
= build_qualified_type (ot
, TYPE_QUALS (ot
) | TYPE_QUAL_CONST
);
1729 val
= assign_temp (nt
, 0, 0, 1);
1730 val
= expand_expr (retval_rhs
, val
, GET_MODE (val
), 0);
1731 val
= force_not_mem (val
);
1732 /* Return the calculated value. */
1733 expand_value_return (val
);
1737 /* No hard reg used; calculate value into hard return reg. */
1738 expand_expr (retval
, const0_rtx
, VOIDmode
, 0);
1739 expand_value_return (result_rtl
);
1743 /* Given a pointer to a BLOCK node return nonzero if (and only if) the node
1744 in question represents the outermost pair of curly braces (i.e. the "body
1745 block") of a function or method.
1747 For any BLOCK node representing a "body block" of a function or method, the
1748 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
1749 represents the outermost (function) scope for the function or method (i.e.
1750 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
1751 *that* node in turn will point to the relevant FUNCTION_DECL node. */
1754 is_body_block (tree stmt
)
1756 if (lang_hooks
.no_body_blocks
)
1759 if (TREE_CODE (stmt
) == BLOCK
)
1761 tree parent
= BLOCK_SUPERCONTEXT (stmt
);
1763 if (parent
&& TREE_CODE (parent
) == BLOCK
)
1765 tree grandparent
= BLOCK_SUPERCONTEXT (parent
);
1767 if (grandparent
&& TREE_CODE (grandparent
) == FUNCTION_DECL
)
1775 /* Emit code to restore vital registers at the beginning of a nonlocal goto
1778 expand_nl_goto_receiver (void)
1780 /* Clobber the FP when we get here, so we have to make sure it's
1781 marked as used by this function. */
1782 emit_insn (gen_rtx_USE (VOIDmode
, hard_frame_pointer_rtx
));
1784 /* Mark the static chain as clobbered here so life information
1785 doesn't get messed up for it. */
1786 emit_insn (gen_rtx_CLOBBER (VOIDmode
, static_chain_rtx
));
1788 #ifdef HAVE_nonlocal_goto
1789 if (! HAVE_nonlocal_goto
)
1791 /* First adjust our frame pointer to its actual value. It was
1792 previously set to the start of the virtual area corresponding to
1793 the stacked variables when we branched here and now needs to be
1794 adjusted to the actual hardware fp value.
1796 Assignments are to virtual registers are converted by
1797 instantiate_virtual_regs into the corresponding assignment
1798 to the underlying register (fp in this case) that makes
1799 the original assignment true.
1800 So the following insn will actually be
1801 decrementing fp by STARTING_FRAME_OFFSET. */
1802 emit_move_insn (virtual_stack_vars_rtx
, hard_frame_pointer_rtx
);
1804 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
1805 if (fixed_regs
[ARG_POINTER_REGNUM
])
1807 #ifdef ELIMINABLE_REGS
1808 /* If the argument pointer can be eliminated in favor of the
1809 frame pointer, we don't need to restore it. We assume here
1810 that if such an elimination is present, it can always be used.
1811 This is the case on all known machines; if we don't make this
1812 assumption, we do unnecessary saving on many machines. */
1813 static const struct elims
{const int from
, to
;} elim_regs
[] = ELIMINABLE_REGS
;
1816 for (i
= 0; i
< ARRAY_SIZE (elim_regs
); i
++)
1817 if (elim_regs
[i
].from
== ARG_POINTER_REGNUM
1818 && elim_regs
[i
].to
== HARD_FRAME_POINTER_REGNUM
)
1821 if (i
== ARRAY_SIZE (elim_regs
))
1824 /* Now restore our arg pointer from the address at which it
1825 was saved in our stack frame. */
1826 emit_move_insn (virtual_incoming_args_rtx
,
1827 copy_to_reg (get_arg_pointer_save_area (cfun
)));
1832 #ifdef HAVE_nonlocal_goto_receiver
1833 if (HAVE_nonlocal_goto_receiver
)
1834 emit_insn (gen_nonlocal_goto_receiver ());
1837 /* @@@ This is a kludge. Not all machine descriptions define a blockage
1838 insn, but we must not allow the code we just generated to be reordered
1839 by scheduling. Specifically, the update of the frame pointer must
1840 happen immediately, not later. So emit an ASM_INPUT to act as blockage
1842 emit_insn (gen_rtx_ASM_INPUT (VOIDmode
, ""));
1845 /* Generate RTL for the automatic variable declaration DECL.
1846 (Other kinds of declarations are simply ignored if seen here.) */
1849 expand_decl (tree decl
)
1853 type
= TREE_TYPE (decl
);
1855 /* For a CONST_DECL, set mode, alignment, and sizes from those of the
1856 type in case this node is used in a reference. */
1857 if (TREE_CODE (decl
) == CONST_DECL
)
1859 DECL_MODE (decl
) = TYPE_MODE (type
);
1860 DECL_ALIGN (decl
) = TYPE_ALIGN (type
);
1861 DECL_SIZE (decl
) = TYPE_SIZE (type
);
1862 DECL_SIZE_UNIT (decl
) = TYPE_SIZE_UNIT (type
);
1866 /* Otherwise, only automatic variables need any expansion done. Static and
1867 external variables, and external functions, will be handled by
1868 `assemble_variable' (called from finish_decl). TYPE_DECL requires
1869 nothing. PARM_DECLs are handled in `assign_parms'. */
1870 if (TREE_CODE (decl
) != VAR_DECL
)
1873 if (TREE_STATIC (decl
) || DECL_EXTERNAL (decl
))
1876 /* Create the RTL representation for the variable. */
1878 if (type
== error_mark_node
)
1879 SET_DECL_RTL (decl
, gen_rtx_MEM (BLKmode
, const0_rtx
));
1881 else if (DECL_SIZE (decl
) == 0)
1882 /* Variable with incomplete type. */
1885 if (DECL_INITIAL (decl
) == 0)
1886 /* Error message was already done; now avoid a crash. */
1887 x
= gen_rtx_MEM (BLKmode
, const0_rtx
);
1889 /* An initializer is going to decide the size of this array.
1890 Until we know the size, represent its address with a reg. */
1891 x
= gen_rtx_MEM (BLKmode
, gen_reg_rtx (Pmode
));
1893 set_mem_attributes (x
, decl
, 1);
1894 SET_DECL_RTL (decl
, x
);
1896 else if (use_register_for_decl (decl
))
1898 /* Automatic variable that can go in a register. */
1899 int unsignedp
= TYPE_UNSIGNED (type
);
1900 enum machine_mode reg_mode
1901 = promote_mode (type
, DECL_MODE (decl
), &unsignedp
, 0);
1903 SET_DECL_RTL (decl
, gen_reg_rtx (reg_mode
));
1905 /* Note if the object is a user variable. */
1906 if (!DECL_ARTIFICIAL (decl
))
1908 mark_user_reg (DECL_RTL (decl
));
1910 /* Trust user variables which have a pointer type to really
1911 be pointers. Do not trust compiler generated temporaries
1912 as our type system is totally busted as it relates to
1913 pointer arithmetic which translates into lots of compiler
1914 generated objects with pointer types, but which are not really
1916 if (POINTER_TYPE_P (type
))
1917 mark_reg_pointer (DECL_RTL (decl
),
1918 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl
))));
1922 else if (TREE_CODE (DECL_SIZE_UNIT (decl
)) == INTEGER_CST
1923 && ! (flag_stack_check
&& ! STACK_CHECK_BUILTIN
1924 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl
),
1925 STACK_CHECK_MAX_VAR_SIZE
)))
1927 /* Variable of fixed size that goes on the stack. */
1932 /* If we previously made RTL for this decl, it must be an array
1933 whose size was determined by the initializer.
1934 The old address was a register; set that register now
1935 to the proper address. */
1936 if (DECL_RTL_SET_P (decl
))
1938 gcc_assert (MEM_P (DECL_RTL (decl
)));
1939 gcc_assert (REG_P (XEXP (DECL_RTL (decl
), 0)));
1940 oldaddr
= XEXP (DECL_RTL (decl
), 0);
1943 /* Set alignment we actually gave this decl. */
1944 DECL_ALIGN (decl
) = (DECL_MODE (decl
) == BLKmode
? BIGGEST_ALIGNMENT
1945 : GET_MODE_BITSIZE (DECL_MODE (decl
)));
1946 DECL_USER_ALIGN (decl
) = 0;
1948 x
= assign_temp (decl
, 1, 1, 1);
1949 set_mem_attributes (x
, decl
, 1);
1950 SET_DECL_RTL (decl
, x
);
1954 addr
= force_operand (XEXP (DECL_RTL (decl
), 0), oldaddr
);
1955 if (addr
!= oldaddr
)
1956 emit_move_insn (oldaddr
, addr
);
1960 /* Dynamic-size object: must push space on the stack. */
1962 rtx address
, size
, x
;
1964 /* Record the stack pointer on entry to block, if have
1965 not already done so. */
1966 do_pending_stack_adjust ();
1968 /* Compute the variable's size, in bytes. This will expand any
1969 needed SAVE_EXPRs for the first time. */
1970 size
= expand_normal (DECL_SIZE_UNIT (decl
));
1973 /* Allocate space on the stack for the variable. Note that
1974 DECL_ALIGN says how the variable is to be aligned and we
1975 cannot use it to conclude anything about the alignment of
1977 address
= allocate_dynamic_stack_space (size
, NULL_RTX
,
1978 TYPE_ALIGN (TREE_TYPE (decl
)));
1980 /* Reference the variable indirect through that rtx. */
1981 x
= gen_rtx_MEM (DECL_MODE (decl
), address
);
1982 set_mem_attributes (x
, decl
, 1);
1983 SET_DECL_RTL (decl
, x
);
1986 /* Indicate the alignment we actually gave this variable. */
1987 #ifdef STACK_BOUNDARY
1988 DECL_ALIGN (decl
) = STACK_BOUNDARY
;
1990 DECL_ALIGN (decl
) = BIGGEST_ALIGNMENT
;
1992 DECL_USER_ALIGN (decl
) = 0;
1996 /* Emit code to save the current value of stack. */
1998 expand_stack_save (void)
2002 do_pending_stack_adjust ();
2003 emit_stack_save (SAVE_BLOCK
, &ret
, NULL_RTX
);
2007 /* Emit code to restore the current value of stack. */
2009 expand_stack_restore (tree var
)
2011 rtx sa
= DECL_RTL (var
);
2013 emit_stack_restore (SAVE_BLOCK
, sa
, NULL_RTX
);
2016 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
2017 DECL_ELTS is the list of elements that belong to DECL's type.
2018 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
2021 expand_anon_union_decl (tree decl
, tree cleanup ATTRIBUTE_UNUSED
,
2027 /* If any of the elements are addressable, so is the entire union. */
2028 for (t
= decl_elts
; t
; t
= TREE_CHAIN (t
))
2029 if (TREE_ADDRESSABLE (TREE_VALUE (t
)))
2031 TREE_ADDRESSABLE (decl
) = 1;
2036 x
= DECL_RTL (decl
);
2038 /* Go through the elements, assigning RTL to each. */
2039 for (t
= decl_elts
; t
; t
= TREE_CHAIN (t
))
2041 tree decl_elt
= TREE_VALUE (t
);
2042 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (decl_elt
));
2045 /* If any of the elements are addressable, so is the entire
2047 if (TREE_USED (decl_elt
))
2048 TREE_USED (decl
) = 1;
2050 /* Propagate the union's alignment to the elements. */
2051 DECL_ALIGN (decl_elt
) = DECL_ALIGN (decl
);
2052 DECL_USER_ALIGN (decl_elt
) = DECL_USER_ALIGN (decl
);
2054 /* If the element has BLKmode and the union doesn't, the union is
2055 aligned such that the element doesn't need to have BLKmode, so
2056 change the element's mode to the appropriate one for its size. */
2057 if (mode
== BLKmode
&& DECL_MODE (decl
) != BLKmode
)
2058 DECL_MODE (decl_elt
) = mode
2059 = mode_for_size_tree (DECL_SIZE (decl_elt
), MODE_INT
, 1);
2061 if (mode
== GET_MODE (x
))
2064 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
2065 instead create a new MEM rtx with the proper mode. */
2066 decl_rtl
= adjust_address_nv (x
, mode
, 0);
2069 gcc_assert (REG_P (x
));
2070 decl_rtl
= gen_lowpart_SUBREG (mode
, x
);
2072 SET_DECL_RTL (decl_elt
, decl_rtl
);
2076 /* Do the insertion of a case label into case_list. The labels are
2077 fed to us in descending order from the sorted vector of case labels used
2078 in the tree part of the middle end. So the list we construct is
2079 sorted in ascending order. The bounds on the case range, LOW and HIGH,
2080 are converted to case's index type TYPE. */
2082 static struct case_node
*
2083 add_case_node (struct case_node
*head
, tree type
, tree low
, tree high
,
2086 tree min_value
, max_value
;
2087 struct case_node
*r
;
2089 gcc_assert (TREE_CODE (low
) == INTEGER_CST
);
2090 gcc_assert (!high
|| TREE_CODE (high
) == INTEGER_CST
);
2092 min_value
= TYPE_MIN_VALUE (type
);
2093 max_value
= TYPE_MAX_VALUE (type
);
2095 /* If there's no HIGH value, then this is not a case range; it's
2096 just a simple case label. But that's just a degenerate case
2098 If the bounds are equal, turn this into the one-value case. */
2099 if (!high
|| tree_int_cst_equal (low
, high
))
2101 /* If the simple case value is unreachable, ignore it. */
2102 if ((TREE_CODE (min_value
) == INTEGER_CST
2103 && tree_int_cst_compare (low
, min_value
) < 0)
2104 || (TREE_CODE (max_value
) == INTEGER_CST
2105 && tree_int_cst_compare (low
, max_value
) > 0))
2107 low
= fold_convert (type
, low
);
2112 /* If the entire case range is unreachable, ignore it. */
2113 if ((TREE_CODE (min_value
) == INTEGER_CST
2114 && tree_int_cst_compare (high
, min_value
) < 0)
2115 || (TREE_CODE (max_value
) == INTEGER_CST
2116 && tree_int_cst_compare (low
, max_value
) > 0))
2119 /* If the lower bound is less than the index type's minimum
2120 value, truncate the range bounds. */
2121 if (TREE_CODE (min_value
) == INTEGER_CST
2122 && tree_int_cst_compare (low
, min_value
) < 0)
2124 low
= fold_convert (type
, low
);
2126 /* If the upper bound is greater than the index type's maximum
2127 value, truncate the range bounds. */
2128 if (TREE_CODE (max_value
) == INTEGER_CST
2129 && tree_int_cst_compare (high
, max_value
) > 0)
2131 high
= fold_convert (type
, high
);
2135 /* Add this label to the chain. Make sure to drop overflow flags. */
2136 r
= ggc_alloc (sizeof (struct case_node
));
2137 r
->low
= build_int_cst_wide (TREE_TYPE (low
), TREE_INT_CST_LOW (low
),
2138 TREE_INT_CST_HIGH (low
));
2139 r
->high
= build_int_cst_wide (TREE_TYPE (high
), TREE_INT_CST_LOW (high
),
2140 TREE_INT_CST_HIGH (high
));
2141 r
->code_label
= label
;
2142 r
->parent
= r
->left
= NULL
;
2147 /* Maximum number of case bit tests. */
2148 #define MAX_CASE_BIT_TESTS 3
2150 /* By default, enable case bit tests on targets with ashlsi3. */
2151 #ifndef CASE_USE_BIT_TESTS
2152 #define CASE_USE_BIT_TESTS (ashl_optab->handlers[word_mode].insn_code \
2153 != CODE_FOR_nothing)
2157 /* A case_bit_test represents a set of case nodes that may be
2158 selected from using a bit-wise comparison. HI and LO hold
2159 the integer to be tested against, LABEL contains the label
2160 to jump to upon success and BITS counts the number of case
2161 nodes handled by this test, typically the number of bits
2164 struct case_bit_test
2172 /* Determine whether "1 << x" is relatively cheap in word_mode. */
2175 bool lshift_cheap_p (void)
2177 static bool init
= false;
2178 static bool cheap
= true;
2182 rtx reg
= gen_rtx_REG (word_mode
, 10000);
2183 int cost
= rtx_cost (gen_rtx_ASHIFT (word_mode
, const1_rtx
, reg
), SET
);
2184 cheap
= cost
< COSTS_N_INSNS (3);
2191 /* Comparison function for qsort to order bit tests by decreasing
2192 number of case nodes, i.e. the node with the most cases gets
2196 case_bit_test_cmp (const void *p1
, const void *p2
)
2198 const struct case_bit_test
*d1
= p1
;
2199 const struct case_bit_test
*d2
= p2
;
2201 if (d2
->bits
!= d1
->bits
)
2202 return d2
->bits
- d1
->bits
;
2204 /* Stabilize the sort. */
2205 return CODE_LABEL_NUMBER (d2
->label
) - CODE_LABEL_NUMBER (d1
->label
);
2208 /* Expand a switch statement by a short sequence of bit-wise
2209 comparisons. "switch(x)" is effectively converted into
2210 "if ((1 << (x-MINVAL)) & CST)" where CST and MINVAL are
2213 INDEX_EXPR is the value being switched on, which is of
2214 type INDEX_TYPE. MINVAL is the lowest case value of in
2215 the case nodes, of INDEX_TYPE type, and RANGE is highest
2216 value minus MINVAL, also of type INDEX_TYPE. NODES is
2217 the set of case nodes, and DEFAULT_LABEL is the label to
2218 branch to should none of the cases match.
2220 There *MUST* be MAX_CASE_BIT_TESTS or less unique case
2224 emit_case_bit_tests (tree index_type
, tree index_expr
, tree minval
,
2225 tree range
, case_node_ptr nodes
, rtx default_label
)
2227 struct case_bit_test test
[MAX_CASE_BIT_TESTS
];
2228 enum machine_mode mode
;
2229 rtx expr
, index
, label
;
2230 unsigned int i
,j
,lo
,hi
;
2231 struct case_node
*n
;
2235 for (n
= nodes
; n
; n
= n
->right
)
2237 label
= label_rtx (n
->code_label
);
2238 for (i
= 0; i
< count
; i
++)
2239 if (label
== test
[i
].label
)
2244 gcc_assert (count
< MAX_CASE_BIT_TESTS
);
2247 test
[i
].label
= label
;
2254 lo
= tree_low_cst (fold_build2 (MINUS_EXPR
, index_type
,
2255 n
->low
, minval
), 1);
2256 hi
= tree_low_cst (fold_build2 (MINUS_EXPR
, index_type
,
2257 n
->high
, minval
), 1);
2258 for (j
= lo
; j
<= hi
; j
++)
2259 if (j
>= HOST_BITS_PER_WIDE_INT
)
2260 test
[i
].hi
|= (HOST_WIDE_INT
) 1 << (j
- HOST_BITS_PER_INT
);
2262 test
[i
].lo
|= (HOST_WIDE_INT
) 1 << j
;
2265 qsort (test
, count
, sizeof(*test
), case_bit_test_cmp
);
2267 index_expr
= fold_build2 (MINUS_EXPR
, index_type
,
2268 fold_convert (index_type
, index_expr
),
2269 fold_convert (index_type
, minval
));
2270 index
= expand_normal (index_expr
);
2271 do_pending_stack_adjust ();
2273 mode
= TYPE_MODE (index_type
);
2274 expr
= expand_normal (range
);
2275 emit_cmp_and_jump_insns (index
, expr
, GTU
, NULL_RTX
, mode
, 1,
2278 index
= convert_to_mode (word_mode
, index
, 0);
2279 index
= expand_binop (word_mode
, ashl_optab
, const1_rtx
,
2280 index
, NULL_RTX
, 1, OPTAB_WIDEN
);
2282 for (i
= 0; i
< count
; i
++)
2284 expr
= immed_double_const (test
[i
].lo
, test
[i
].hi
, word_mode
);
2285 expr
= expand_binop (word_mode
, and_optab
, index
, expr
,
2286 NULL_RTX
, 1, OPTAB_WIDEN
);
2287 emit_cmp_and_jump_insns (expr
, const0_rtx
, NE
, NULL_RTX
,
2288 word_mode
, 1, test
[i
].label
);
2291 emit_jump (default_label
);
2295 #define HAVE_casesi 0
2298 #ifndef HAVE_tablejump
2299 #define HAVE_tablejump 0
2302 /* Terminate a case (Pascal/Ada) or switch (C) statement
2303 in which ORIG_INDEX is the expression to be tested.
2304 If ORIG_TYPE is not NULL, it is the original ORIG_INDEX
2305 type as given in the source before any compiler conversions.
2306 Generate the code to test it and jump to the right place. */
2309 expand_case (tree exp
)
2311 tree minval
= NULL_TREE
, maxval
= NULL_TREE
, range
= NULL_TREE
;
2312 rtx default_label
= 0;
2313 struct case_node
*n
;
2314 unsigned int count
, uniq
;
2320 rtx before_case
, end
, lab
;
2322 tree vec
= SWITCH_LABELS (exp
);
2323 tree orig_type
= TREE_TYPE (exp
);
2324 tree index_expr
= SWITCH_COND (exp
);
2325 tree index_type
= TREE_TYPE (index_expr
);
2326 int unsignedp
= TYPE_UNSIGNED (index_type
);
2328 /* The insn after which the case dispatch should finally
2329 be emitted. Zero for a dummy. */
2332 /* A list of case labels; it is first built as a list and it may then
2333 be rearranged into a nearly balanced binary tree. */
2334 struct case_node
*case_list
= 0;
2336 /* Label to jump to if no case matches. */
2337 tree default_label_decl
;
2339 /* The switch body is lowered in gimplify.c, we should never have
2340 switches with a non-NULL SWITCH_BODY here. */
2341 gcc_assert (!SWITCH_BODY (exp
));
2342 gcc_assert (SWITCH_LABELS (exp
));
2344 do_pending_stack_adjust ();
2346 /* An ERROR_MARK occurs for various reasons including invalid data type. */
2347 if (index_type
!= error_mark_node
)
2350 bitmap label_bitmap
;
2352 /* cleanup_tree_cfg removes all SWITCH_EXPR with their index
2353 expressions being INTEGER_CST. */
2354 gcc_assert (TREE_CODE (index_expr
) != INTEGER_CST
);
2356 /* The default case is at the end of TREE_VEC. */
2357 elt
= TREE_VEC_ELT (vec
, TREE_VEC_LENGTH (vec
) - 1);
2358 gcc_assert (!CASE_HIGH (elt
));
2359 gcc_assert (!CASE_LOW (elt
));
2360 default_label_decl
= CASE_LABEL (elt
);
2362 for (i
= TREE_VEC_LENGTH (vec
) - 1; --i
>= 0; )
2365 elt
= TREE_VEC_ELT (vec
, i
);
2367 low
= CASE_LOW (elt
);
2369 high
= CASE_HIGH (elt
);
2371 /* Discard empty ranges. */
2372 if (high
&& INT_CST_LT (high
, low
))
2375 case_list
= add_case_node (case_list
, index_type
, low
, high
,
2380 before_case
= start
= get_last_insn ();
2381 default_label
= label_rtx (default_label_decl
);
2383 /* Get upper and lower bounds of case values. */
2387 label_bitmap
= BITMAP_ALLOC (NULL
);
2388 for (n
= case_list
; n
; n
= n
->right
)
2390 /* Count the elements and track the largest and smallest
2391 of them (treating them as signed even if they are not). */
2399 if (INT_CST_LT (n
->low
, minval
))
2401 if (INT_CST_LT (maxval
, n
->high
))
2404 /* A range counts double, since it requires two compares. */
2405 if (! tree_int_cst_equal (n
->low
, n
->high
))
2408 /* If we have not seen this label yet, then increase the
2409 number of unique case node targets seen. */
2410 lab
= label_rtx (n
->code_label
);
2411 if (!bitmap_bit_p (label_bitmap
, CODE_LABEL_NUMBER (lab
)))
2413 bitmap_set_bit (label_bitmap
, CODE_LABEL_NUMBER (lab
));
2418 BITMAP_FREE (label_bitmap
);
2420 /* cleanup_tree_cfg removes all SWITCH_EXPR with a single
2421 destination, such as one with a default case only. However,
2422 it doesn't remove cases that are out of range for the switch
2423 type, so we may still get a zero here. */
2426 emit_jump (default_label
);
2430 /* Compute span of values. */
2431 range
= fold_build2 (MINUS_EXPR
, index_type
, maxval
, minval
);
2433 /* Try implementing this switch statement by a short sequence of
2434 bit-wise comparisons. However, we let the binary-tree case
2435 below handle constant index expressions. */
2436 if (CASE_USE_BIT_TESTS
2437 && ! TREE_CONSTANT (index_expr
)
2438 && compare_tree_int (range
, GET_MODE_BITSIZE (word_mode
)) < 0
2439 && compare_tree_int (range
, 0) > 0
2440 && lshift_cheap_p ()
2441 && ((uniq
== 1 && count
>= 3)
2442 || (uniq
== 2 && count
>= 5)
2443 || (uniq
== 3 && count
>= 6)))
2445 /* Optimize the case where all the case values fit in a
2446 word without having to subtract MINVAL. In this case,
2447 we can optimize away the subtraction. */
2448 if (compare_tree_int (minval
, 0) > 0
2449 && compare_tree_int (maxval
, GET_MODE_BITSIZE (word_mode
)) < 0)
2451 minval
= build_int_cst (index_type
, 0);
2454 emit_case_bit_tests (index_type
, index_expr
, minval
, range
,
2455 case_list
, default_label
);
2458 /* If range of values is much bigger than number of values,
2459 make a sequence of conditional branches instead of a dispatch.
2460 If the switch-index is a constant, do it this way
2461 because we can optimize it. */
2463 else if (count
< case_values_threshold ()
2464 || compare_tree_int (range
,
2465 (optimize_size
? 3 : 10) * count
) > 0
2466 /* RANGE may be signed, and really large ranges will show up
2467 as negative numbers. */
2468 || compare_tree_int (range
, 0) < 0
2469 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
2472 || !flag_jump_tables
2473 || TREE_CONSTANT (index_expr
)
2474 /* If neither casesi or tablejump is available, we can
2475 only go this way. */
2476 || (!HAVE_casesi
&& !HAVE_tablejump
))
2478 index
= expand_normal (index_expr
);
2480 /* If the index is a short or char that we do not have
2481 an insn to handle comparisons directly, convert it to
2482 a full integer now, rather than letting each comparison
2483 generate the conversion. */
2485 if (GET_MODE_CLASS (GET_MODE (index
)) == MODE_INT
2486 && ! have_insn_for (COMPARE
, GET_MODE (index
)))
2488 enum machine_mode wider_mode
;
2489 for (wider_mode
= GET_MODE (index
); wider_mode
!= VOIDmode
;
2490 wider_mode
= GET_MODE_WIDER_MODE (wider_mode
))
2491 if (have_insn_for (COMPARE
, wider_mode
))
2493 index
= convert_to_mode (wider_mode
, index
, unsignedp
);
2498 do_pending_stack_adjust ();
2501 index
= copy_to_reg (index
);
2503 /* We generate a binary decision tree to select the
2504 appropriate target code. This is done as follows:
2506 The list of cases is rearranged into a binary tree,
2507 nearly optimal assuming equal probability for each case.
2509 The tree is transformed into RTL, eliminating
2510 redundant test conditions at the same time.
2512 If program flow could reach the end of the
2513 decision tree an unconditional jump to the
2514 default code is emitted. */
2517 = (TREE_CODE (orig_type
) != ENUMERAL_TYPE
2518 && estimate_case_costs (case_list
));
2519 balance_case_nodes (&case_list
, NULL
);
2520 emit_case_nodes (index
, case_list
, default_label
, index_type
);
2521 emit_jump (default_label
);
2525 table_label
= gen_label_rtx ();
2526 if (! try_casesi (index_type
, index_expr
, minval
, range
,
2527 table_label
, default_label
))
2531 /* Index jumptables from zero for suitable values of
2532 minval to avoid a subtraction. */
2534 && compare_tree_int (minval
, 0) > 0
2535 && compare_tree_int (minval
, 3) < 0)
2537 minval
= build_int_cst (index_type
, 0);
2541 ok
= try_tablejump (index_type
, index_expr
, minval
, range
,
2542 table_label
, default_label
);
2546 /* Get table of labels to jump to, in order of case index. */
2548 ncases
= tree_low_cst (range
, 0) + 1;
2549 labelvec
= alloca (ncases
* sizeof (rtx
));
2550 memset (labelvec
, 0, ncases
* sizeof (rtx
));
2552 for (n
= case_list
; n
; n
= n
->right
)
2554 /* Compute the low and high bounds relative to the minimum
2555 value since that should fit in a HOST_WIDE_INT while the
2556 actual values may not. */
2558 = tree_low_cst (fold_build2 (MINUS_EXPR
, index_type
,
2559 n
->low
, minval
), 1);
2560 HOST_WIDE_INT i_high
2561 = tree_low_cst (fold_build2 (MINUS_EXPR
, index_type
,
2562 n
->high
, minval
), 1);
2565 for (i
= i_low
; i
<= i_high
; i
++)
2567 = gen_rtx_LABEL_REF (Pmode
, label_rtx (n
->code_label
));
2570 /* Fill in the gaps with the default. */
2571 for (i
= 0; i
< ncases
; i
++)
2572 if (labelvec
[i
] == 0)
2573 labelvec
[i
] = gen_rtx_LABEL_REF (Pmode
, default_label
);
2575 /* Output the table. */
2576 emit_label (table_label
);
2578 if (CASE_VECTOR_PC_RELATIVE
|| flag_pic
)
2579 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE
,
2580 gen_rtx_LABEL_REF (Pmode
, table_label
),
2581 gen_rtvec_v (ncases
, labelvec
),
2582 const0_rtx
, const0_rtx
));
2584 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE
,
2585 gen_rtvec_v (ncases
, labelvec
)));
2587 /* Record no drop-through after the table. */
2591 before_case
= NEXT_INSN (before_case
);
2592 end
= get_last_insn ();
2593 fail
= squeeze_notes (&before_case
, &end
);
2595 reorder_insns (before_case
, end
, start
);
2601 /* Generate code to jump to LABEL if OP0 and OP1 are equal in mode MODE. */
2604 do_jump_if_equal (enum machine_mode mode
, rtx op0
, rtx op1
, rtx label
,
2607 do_compare_rtx_and_jump (op0
, op1
, EQ
, unsignedp
, mode
,
2608 NULL_RTX
, NULL_RTX
, label
);
2611 /* Not all case values are encountered equally. This function
2612 uses a heuristic to weight case labels, in cases where that
2613 looks like a reasonable thing to do.
2615 Right now, all we try to guess is text, and we establish the
2618 chars above space: 16
2627 If we find any cases in the switch that are not either -1 or in the range
2628 of valid ASCII characters, or are control characters other than those
2629 commonly used with "\", don't treat this switch scanning text.
2631 Return 1 if these nodes are suitable for cost estimation, otherwise
2635 estimate_case_costs (case_node_ptr node
)
2637 tree min_ascii
= integer_minus_one_node
;
2638 tree max_ascii
= build_int_cst (TREE_TYPE (node
->high
), 127);
2642 /* If we haven't already made the cost table, make it now. Note that the
2643 lower bound of the table is -1, not zero. */
2645 if (! cost_table_initialized
)
2647 cost_table_initialized
= 1;
2649 for (i
= 0; i
< 128; i
++)
2652 COST_TABLE (i
) = 16;
2653 else if (ISPUNCT (i
))
2655 else if (ISCNTRL (i
))
2656 COST_TABLE (i
) = -1;
2659 COST_TABLE (' ') = 8;
2660 COST_TABLE ('\t') = 4;
2661 COST_TABLE ('\0') = 4;
2662 COST_TABLE ('\n') = 2;
2663 COST_TABLE ('\f') = 1;
2664 COST_TABLE ('\v') = 1;
2665 COST_TABLE ('\b') = 1;
2668 /* See if all the case expressions look like text. It is text if the
2669 constant is >= -1 and the highest constant is <= 127. Do all comparisons
2670 as signed arithmetic since we don't want to ever access cost_table with a
2671 value less than -1. Also check that none of the constants in a range
2672 are strange control characters. */
2674 for (n
= node
; n
; n
= n
->right
)
2676 if ((INT_CST_LT (n
->low
, min_ascii
)) || INT_CST_LT (max_ascii
, n
->high
))
2679 for (i
= (HOST_WIDE_INT
) TREE_INT_CST_LOW (n
->low
);
2680 i
<= (HOST_WIDE_INT
) TREE_INT_CST_LOW (n
->high
); i
++)
2681 if (COST_TABLE (i
) < 0)
2685 /* All interesting values are within the range of interesting
2686 ASCII characters. */
2690 /* Take an ordered list of case nodes
2691 and transform them into a near optimal binary tree,
2692 on the assumption that any target code selection value is as
2693 likely as any other.
2695 The transformation is performed by splitting the ordered
2696 list into two equal sections plus a pivot. The parts are
2697 then attached to the pivot as left and right branches. Each
2698 branch is then transformed recursively. */
2701 balance_case_nodes (case_node_ptr
*head
, case_node_ptr parent
)
2714 /* Count the number of entries on branch. Also count the ranges. */
2718 if (!tree_int_cst_equal (np
->low
, np
->high
))
2722 cost
+= COST_TABLE (TREE_INT_CST_LOW (np
->high
));
2726 cost
+= COST_TABLE (TREE_INT_CST_LOW (np
->low
));
2734 /* Split this list if it is long enough for that to help. */
2739 /* Find the place in the list that bisects the list's total cost,
2740 Here I gets half the total cost. */
2745 /* Skip nodes while their cost does not reach that amount. */
2746 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
2747 i
-= COST_TABLE (TREE_INT_CST_LOW ((*npp
)->high
));
2748 i
-= COST_TABLE (TREE_INT_CST_LOW ((*npp
)->low
));
2751 npp
= &(*npp
)->right
;
2756 /* Leave this branch lopsided, but optimize left-hand
2757 side and fill in `parent' fields for right-hand side. */
2759 np
->parent
= parent
;
2760 balance_case_nodes (&np
->left
, np
);
2761 for (; np
->right
; np
= np
->right
)
2762 np
->right
->parent
= np
;
2766 /* If there are just three nodes, split at the middle one. */
2768 npp
= &(*npp
)->right
;
2771 /* Find the place in the list that bisects the list's total cost,
2772 where ranges count as 2.
2773 Here I gets half the total cost. */
2774 i
= (i
+ ranges
+ 1) / 2;
2777 /* Skip nodes while their cost does not reach that amount. */
2778 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
2783 npp
= &(*npp
)->right
;
2788 np
->parent
= parent
;
2791 /* Optimize each of the two split parts. */
2792 balance_case_nodes (&np
->left
, np
);
2793 balance_case_nodes (&np
->right
, np
);
2797 /* Else leave this branch as one level,
2798 but fill in `parent' fields. */
2800 np
->parent
= parent
;
2801 for (; np
->right
; np
= np
->right
)
2802 np
->right
->parent
= np
;
2807 /* Search the parent sections of the case node tree
2808 to see if a test for the lower bound of NODE would be redundant.
2809 INDEX_TYPE is the type of the index expression.
2811 The instructions to generate the case decision tree are
2812 output in the same order as nodes are processed so it is
2813 known that if a parent node checks the range of the current
2814 node minus one that the current node is bounded at its lower
2815 span. Thus the test would be redundant. */
2818 node_has_low_bound (case_node_ptr node
, tree index_type
)
2821 case_node_ptr pnode
;
2823 /* If the lower bound of this node is the lowest value in the index type,
2824 we need not test it. */
2826 if (tree_int_cst_equal (node
->low
, TYPE_MIN_VALUE (index_type
)))
2829 /* If this node has a left branch, the value at the left must be less
2830 than that at this node, so it cannot be bounded at the bottom and
2831 we need not bother testing any further. */
2836 low_minus_one
= fold_build2 (MINUS_EXPR
, TREE_TYPE (node
->low
),
2838 build_int_cst (TREE_TYPE (node
->low
), 1));
2840 /* If the subtraction above overflowed, we can't verify anything.
2841 Otherwise, look for a parent that tests our value - 1. */
2843 if (! tree_int_cst_lt (low_minus_one
, node
->low
))
2846 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
2847 if (tree_int_cst_equal (low_minus_one
, pnode
->high
))
2853 /* Search the parent sections of the case node tree
2854 to see if a test for the upper bound of NODE would be redundant.
2855 INDEX_TYPE is the type of the index expression.
2857 The instructions to generate the case decision tree are
2858 output in the same order as nodes are processed so it is
2859 known that if a parent node checks the range of the current
2860 node plus one that the current node is bounded at its upper
2861 span. Thus the test would be redundant. */
2864 node_has_high_bound (case_node_ptr node
, tree index_type
)
2867 case_node_ptr pnode
;
2869 /* If there is no upper bound, obviously no test is needed. */
2871 if (TYPE_MAX_VALUE (index_type
) == NULL
)
2874 /* If the upper bound of this node is the highest value in the type
2875 of the index expression, we need not test against it. */
2877 if (tree_int_cst_equal (node
->high
, TYPE_MAX_VALUE (index_type
)))
2880 /* If this node has a right branch, the value at the right must be greater
2881 than that at this node, so it cannot be bounded at the top and
2882 we need not bother testing any further. */
2887 high_plus_one
= fold_build2 (PLUS_EXPR
, TREE_TYPE (node
->high
),
2889 build_int_cst (TREE_TYPE (node
->high
), 1));
2891 /* If the addition above overflowed, we can't verify anything.
2892 Otherwise, look for a parent that tests our value + 1. */
2894 if (! tree_int_cst_lt (node
->high
, high_plus_one
))
2897 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
2898 if (tree_int_cst_equal (high_plus_one
, pnode
->low
))
2904 /* Search the parent sections of the
2905 case node tree to see if both tests for the upper and lower
2906 bounds of NODE would be redundant. */
2909 node_is_bounded (case_node_ptr node
, tree index_type
)
2911 return (node_has_low_bound (node
, index_type
)
2912 && node_has_high_bound (node
, index_type
));
2915 /* Emit step-by-step code to select a case for the value of INDEX.
2916 The thus generated decision tree follows the form of the
2917 case-node binary tree NODE, whose nodes represent test conditions.
2918 INDEX_TYPE is the type of the index of the switch.
2920 Care is taken to prune redundant tests from the decision tree
2921 by detecting any boundary conditions already checked by
2922 emitted rtx. (See node_has_high_bound, node_has_low_bound
2923 and node_is_bounded, above.)
2925 Where the test conditions can be shown to be redundant we emit
2926 an unconditional jump to the target code. As a further
2927 optimization, the subordinates of a tree node are examined to
2928 check for bounded nodes. In this case conditional and/or
2929 unconditional jumps as a result of the boundary check for the
2930 current node are arranged to target the subordinates associated
2931 code for out of bound conditions on the current node.
2933 We can assume that when control reaches the code generated here,
2934 the index value has already been compared with the parents
2935 of this node, and determined to be on the same side of each parent
2936 as this node is. Thus, if this node tests for the value 51,
2937 and a parent tested for 52, we don't need to consider
2938 the possibility of a value greater than 51. If another parent
2939 tests for the value 50, then this node need not test anything. */
2942 emit_case_nodes (rtx index
, case_node_ptr node
, rtx default_label
,
2945 /* If INDEX has an unsigned type, we must make unsigned branches. */
2946 int unsignedp
= TYPE_UNSIGNED (index_type
);
2947 enum machine_mode mode
= GET_MODE (index
);
2948 enum machine_mode imode
= TYPE_MODE (index_type
);
2950 /* Handle indices detected as constant during RTL expansion. */
2951 if (mode
== VOIDmode
)
2954 /* See if our parents have already tested everything for us.
2955 If they have, emit an unconditional jump for this node. */
2956 if (node_is_bounded (node
, index_type
))
2957 emit_jump (label_rtx (node
->code_label
));
2959 else if (tree_int_cst_equal (node
->low
, node
->high
))
2961 /* Node is single valued. First see if the index expression matches
2962 this node and then check our children, if any. */
2964 do_jump_if_equal (mode
, index
,
2965 convert_modes (mode
, imode
,
2966 expand_normal (node
->low
),
2968 label_rtx (node
->code_label
), unsignedp
);
2970 if (node
->right
!= 0 && node
->left
!= 0)
2972 /* This node has children on both sides.
2973 Dispatch to one side or the other
2974 by comparing the index value with this node's value.
2975 If one subtree is bounded, check that one first,
2976 so we can avoid real branches in the tree. */
2978 if (node_is_bounded (node
->right
, index_type
))
2980 emit_cmp_and_jump_insns (index
,
2983 expand_normal (node
->high
),
2985 GT
, NULL_RTX
, mode
, unsignedp
,
2986 label_rtx (node
->right
->code_label
));
2987 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
2990 else if (node_is_bounded (node
->left
, index_type
))
2992 emit_cmp_and_jump_insns (index
,
2995 expand_normal (node
->high
),
2997 LT
, NULL_RTX
, mode
, unsignedp
,
2998 label_rtx (node
->left
->code_label
));
2999 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
3002 /* If both children are single-valued cases with no
3003 children, finish up all the work. This way, we can save
3004 one ordered comparison. */
3005 else if (tree_int_cst_equal (node
->right
->low
, node
->right
->high
)
3006 && node
->right
->left
== 0
3007 && node
->right
->right
== 0
3008 && tree_int_cst_equal (node
->left
->low
, node
->left
->high
)
3009 && node
->left
->left
== 0
3010 && node
->left
->right
== 0)
3012 /* Neither node is bounded. First distinguish the two sides;
3013 then emit the code for one side at a time. */
3015 /* See if the value matches what the right hand side
3017 do_jump_if_equal (mode
, index
,
3018 convert_modes (mode
, imode
,
3019 expand_normal (node
->right
->low
),
3021 label_rtx (node
->right
->code_label
),
3024 /* See if the value matches what the left hand side
3026 do_jump_if_equal (mode
, index
,
3027 convert_modes (mode
, imode
,
3028 expand_normal (node
->left
->low
),
3030 label_rtx (node
->left
->code_label
),
3036 /* Neither node is bounded. First distinguish the two sides;
3037 then emit the code for one side at a time. */
3039 tree test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
3041 /* See if the value is on the right. */
3042 emit_cmp_and_jump_insns (index
,
3045 expand_normal (node
->high
),
3047 GT
, NULL_RTX
, mode
, unsignedp
,
3048 label_rtx (test_label
));
3050 /* Value must be on the left.
3051 Handle the left-hand subtree. */
3052 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
3053 /* If left-hand subtree does nothing,
3055 emit_jump (default_label
);
3057 /* Code branches here for the right-hand subtree. */
3058 expand_label (test_label
);
3059 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
3063 else if (node
->right
!= 0 && node
->left
== 0)
3065 /* Here we have a right child but no left so we issue a conditional
3066 branch to default and process the right child.
3068 Omit the conditional branch to default if the right child
3069 does not have any children and is single valued; it would
3070 cost too much space to save so little time. */
3072 if (node
->right
->right
|| node
->right
->left
3073 || !tree_int_cst_equal (node
->right
->low
, node
->right
->high
))
3075 if (!node_has_low_bound (node
, index_type
))
3077 emit_cmp_and_jump_insns (index
,
3080 expand_normal (node
->high
),
3082 LT
, NULL_RTX
, mode
, unsignedp
,
3086 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
3089 /* We cannot process node->right normally
3090 since we haven't ruled out the numbers less than
3091 this node's value. So handle node->right explicitly. */
3092 do_jump_if_equal (mode
, index
,
3095 expand_normal (node
->right
->low
),
3097 label_rtx (node
->right
->code_label
), unsignedp
);
3100 else if (node
->right
== 0 && node
->left
!= 0)
3102 /* Just one subtree, on the left. */
3103 if (node
->left
->left
|| node
->left
->right
3104 || !tree_int_cst_equal (node
->left
->low
, node
->left
->high
))
3106 if (!node_has_high_bound (node
, index_type
))
3108 emit_cmp_and_jump_insns (index
,
3111 expand_normal (node
->high
),
3113 GT
, NULL_RTX
, mode
, unsignedp
,
3117 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
3120 /* We cannot process node->left normally
3121 since we haven't ruled out the numbers less than
3122 this node's value. So handle node->left explicitly. */
3123 do_jump_if_equal (mode
, index
,
3126 expand_normal (node
->left
->low
),
3128 label_rtx (node
->left
->code_label
), unsignedp
);
3133 /* Node is a range. These cases are very similar to those for a single
3134 value, except that we do not start by testing whether this node
3135 is the one to branch to. */
3137 if (node
->right
!= 0 && node
->left
!= 0)
3139 /* Node has subtrees on both sides.
3140 If the right-hand subtree is bounded,
3141 test for it first, since we can go straight there.
3142 Otherwise, we need to make a branch in the control structure,
3143 then handle the two subtrees. */
3144 tree test_label
= 0;
3146 if (node_is_bounded (node
->right
, index_type
))
3147 /* Right hand node is fully bounded so we can eliminate any
3148 testing and branch directly to the target code. */
3149 emit_cmp_and_jump_insns (index
,
3152 expand_normal (node
->high
),
3154 GT
, NULL_RTX
, mode
, unsignedp
,
3155 label_rtx (node
->right
->code_label
));
3158 /* Right hand node requires testing.
3159 Branch to a label where we will handle it later. */
3161 test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
3162 emit_cmp_and_jump_insns (index
,
3165 expand_normal (node
->high
),
3167 GT
, NULL_RTX
, mode
, unsignedp
,
3168 label_rtx (test_label
));
3171 /* Value belongs to this node or to the left-hand subtree. */
3173 emit_cmp_and_jump_insns (index
,
3176 expand_normal (node
->low
),
3178 GE
, NULL_RTX
, mode
, unsignedp
,
3179 label_rtx (node
->code_label
));
3181 /* Handle the left-hand subtree. */
3182 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
3184 /* If right node had to be handled later, do that now. */
3188 /* If the left-hand subtree fell through,
3189 don't let it fall into the right-hand subtree. */
3190 emit_jump (default_label
);
3192 expand_label (test_label
);
3193 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
3197 else if (node
->right
!= 0 && node
->left
== 0)
3199 /* Deal with values to the left of this node,
3200 if they are possible. */
3201 if (!node_has_low_bound (node
, index_type
))
3203 emit_cmp_and_jump_insns (index
,
3206 expand_normal (node
->low
),
3208 LT
, NULL_RTX
, mode
, unsignedp
,
3212 /* Value belongs to this node or to the right-hand subtree. */
3214 emit_cmp_and_jump_insns (index
,
3217 expand_normal (node
->high
),
3219 LE
, NULL_RTX
, mode
, unsignedp
,
3220 label_rtx (node
->code_label
));
3222 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
3225 else if (node
->right
== 0 && node
->left
!= 0)
3227 /* Deal with values to the right of this node,
3228 if they are possible. */
3229 if (!node_has_high_bound (node
, index_type
))
3231 emit_cmp_and_jump_insns (index
,
3234 expand_normal (node
->high
),
3236 GT
, NULL_RTX
, mode
, unsignedp
,
3240 /* Value belongs to this node or to the left-hand subtree. */
3242 emit_cmp_and_jump_insns (index
,
3245 expand_normal (node
->low
),
3247 GE
, NULL_RTX
, mode
, unsignedp
,
3248 label_rtx (node
->code_label
));
3250 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
3255 /* Node has no children so we check low and high bounds to remove
3256 redundant tests. Only one of the bounds can exist,
3257 since otherwise this node is bounded--a case tested already. */
3258 int high_bound
= node_has_high_bound (node
, index_type
);
3259 int low_bound
= node_has_low_bound (node
, index_type
);
3261 if (!high_bound
&& low_bound
)
3263 emit_cmp_and_jump_insns (index
,
3266 expand_normal (node
->high
),
3268 GT
, NULL_RTX
, mode
, unsignedp
,
3272 else if (!low_bound
&& high_bound
)
3274 emit_cmp_and_jump_insns (index
,
3277 expand_normal (node
->low
),
3279 LT
, NULL_RTX
, mode
, unsignedp
,
3282 else if (!low_bound
&& !high_bound
)
3284 /* Widen LOW and HIGH to the same width as INDEX. */
3285 tree type
= lang_hooks
.types
.type_for_mode (mode
, unsignedp
);
3286 tree low
= build1 (CONVERT_EXPR
, type
, node
->low
);
3287 tree high
= build1 (CONVERT_EXPR
, type
, node
->high
);
3288 rtx low_rtx
, new_index
, new_bound
;
3290 /* Instead of doing two branches, emit one unsigned branch for
3291 (index-low) > (high-low). */
3292 low_rtx
= expand_expr (low
, NULL_RTX
, mode
, EXPAND_NORMAL
);
3293 new_index
= expand_simple_binop (mode
, MINUS
, index
, low_rtx
,
3294 NULL_RTX
, unsignedp
,
3296 new_bound
= expand_expr (fold_build2 (MINUS_EXPR
, type
,
3298 NULL_RTX
, mode
, EXPAND_NORMAL
);
3300 emit_cmp_and_jump_insns (new_index
, new_bound
, GT
, NULL_RTX
,
3301 mode
, 1, default_label
);
3304 emit_jump (label_rtx (node
->code_label
));