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
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 void do_jump_if_equal (rtx
, rtx
, rtx
, int);
116 static int estimate_case_costs (case_node_ptr
);
117 static bool lshift_cheap_p (void);
118 static int case_bit_test_cmp (const void *, const void *);
119 static void emit_case_bit_tests (tree
, tree
, tree
, tree
, case_node_ptr
, rtx
);
120 static void balance_case_nodes (case_node_ptr
*, case_node_ptr
);
121 static int node_has_low_bound (case_node_ptr
, tree
);
122 static int node_has_high_bound (case_node_ptr
, tree
);
123 static int node_is_bounded (case_node_ptr
, tree
);
124 static void emit_case_nodes (rtx
, case_node_ptr
, rtx
, tree
);
125 static struct case_node
*add_case_node (struct case_node
*, tree
,
129 /* Return the rtx-label that corresponds to a LABEL_DECL,
130 creating it if necessary. */
133 label_rtx (tree label
)
135 gcc_assert (TREE_CODE (label
) == LABEL_DECL
);
137 if (!DECL_RTL_SET_P (label
))
139 rtx r
= gen_label_rtx ();
140 SET_DECL_RTL (label
, r
);
141 if (FORCED_LABEL (label
) || DECL_NONLOCAL (label
))
142 LABEL_PRESERVE_P (r
) = 1;
145 return DECL_RTL (label
);
148 /* As above, but also put it on the forced-reference list of the
149 function that contains it. */
151 force_label_rtx (tree label
)
153 rtx ref
= label_rtx (label
);
154 tree function
= decl_function_context (label
);
157 gcc_assert (function
);
159 if (function
!= current_function_decl
)
160 p
= find_function_data (function
);
164 p
->expr
->x_forced_labels
= gen_rtx_EXPR_LIST (VOIDmode
, ref
,
165 p
->expr
->x_forced_labels
);
169 /* Add an unconditional jump to LABEL as the next sequential instruction. */
172 emit_jump (rtx label
)
174 do_pending_stack_adjust ();
175 emit_jump_insn (gen_jump (label
));
179 /* Emit code to jump to the address
180 specified by the pointer expression EXP. */
183 expand_computed_goto (tree exp
)
185 rtx x
= expand_normal (exp
);
187 x
= convert_memory_address (Pmode
, x
);
189 do_pending_stack_adjust ();
190 emit_indirect_jump (x
);
193 /* Handle goto statements and the labels that they can go to. */
195 /* Specify the location in the RTL code of a label LABEL,
196 which is a LABEL_DECL tree node.
198 This is used for the kind of label that the user can jump to with a
199 goto statement, and for alternatives of a switch or case statement.
200 RTL labels generated for loops and conditionals don't go through here;
201 they are generated directly at the RTL level, by other functions below.
203 Note that this has nothing to do with defining label *names*.
204 Languages vary in how they do that and what that even means. */
207 expand_label (tree label
)
209 rtx label_r
= label_rtx (label
);
211 do_pending_stack_adjust ();
212 emit_label (label_r
);
213 if (DECL_NAME (label
))
214 LABEL_NAME (DECL_RTL (label
)) = IDENTIFIER_POINTER (DECL_NAME (label
));
216 if (DECL_NONLOCAL (label
))
218 expand_nl_goto_receiver ();
219 nonlocal_goto_handler_labels
220 = gen_rtx_EXPR_LIST (VOIDmode
, label_r
,
221 nonlocal_goto_handler_labels
);
224 if (FORCED_LABEL (label
))
225 forced_labels
= gen_rtx_EXPR_LIST (VOIDmode
, label_r
, forced_labels
);
227 if (DECL_NONLOCAL (label
) || FORCED_LABEL (label
))
228 maybe_set_first_label_num (label_r
);
231 /* Generate RTL code for a `goto' statement with target label LABEL.
232 LABEL should be a LABEL_DECL tree node that was or will later be
233 defined with `expand_label'. */
236 expand_goto (tree label
)
238 #ifdef ENABLE_CHECKING
239 /* Check for a nonlocal goto to a containing function. Should have
240 gotten translated to __builtin_nonlocal_goto. */
241 tree context
= decl_function_context (label
);
242 gcc_assert (!context
|| context
== current_function_decl
);
245 emit_jump (label_rtx (label
));
248 /* Return the number of times character C occurs in string S. */
250 n_occurrences (int c
, const char *s
)
258 /* Generate RTL for an asm statement (explicit assembler code).
259 STRING is a STRING_CST node containing the assembler code text,
260 or an ADDR_EXPR containing a STRING_CST. VOL nonzero means the
261 insn is volatile; don't optimize it. */
264 expand_asm (tree string
, int vol
)
268 if (TREE_CODE (string
) == ADDR_EXPR
)
269 string
= TREE_OPERAND (string
, 0);
271 body
= gen_rtx_ASM_INPUT (VOIDmode
,
272 ggc_strdup (TREE_STRING_POINTER (string
)));
274 MEM_VOLATILE_P (body
) = vol
;
279 /* Parse the output constraint pointed to by *CONSTRAINT_P. It is the
280 OPERAND_NUMth output operand, indexed from zero. There are NINPUTS
281 inputs and NOUTPUTS outputs to this extended-asm. Upon return,
282 *ALLOWS_MEM will be TRUE iff the constraint allows the use of a
283 memory operand. Similarly, *ALLOWS_REG will be TRUE iff the
284 constraint allows the use of a register operand. And, *IS_INOUT
285 will be true if the operand is read-write, i.e., if it is used as
286 an input as well as an output. If *CONSTRAINT_P is not in
287 canonical form, it will be made canonical. (Note that `+' will be
288 replaced with `=' as part of this process.)
290 Returns TRUE if all went well; FALSE if an error occurred. */
293 parse_output_constraint (const char **constraint_p
, int operand_num
,
294 int ninputs
, int noutputs
, bool *allows_mem
,
295 bool *allows_reg
, bool *is_inout
)
297 const char *constraint
= *constraint_p
;
300 /* Assume the constraint doesn't allow the use of either a register
305 /* Allow the `=' or `+' to not be at the beginning of the string,
306 since it wasn't explicitly documented that way, and there is a
307 large body of code that puts it last. Swap the character to
308 the front, so as not to uglify any place else. */
309 p
= strchr (constraint
, '=');
311 p
= strchr (constraint
, '+');
313 /* If the string doesn't contain an `=', issue an error
317 error ("output operand constraint lacks %<=%>");
321 /* If the constraint begins with `+', then the operand is both read
322 from and written to. */
323 *is_inout
= (*p
== '+');
325 /* Canonicalize the output constraint so that it begins with `='. */
326 if (p
!= constraint
|| *is_inout
)
329 size_t c_len
= strlen (constraint
);
332 warning (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
|| TREE_CODE (decl
) == PARM_DECL
)
573 if (DECL_REGISTER (decl
)
574 && REG_P (DECL_RTL (decl
))
575 && REGNO (DECL_RTL (decl
)) < FIRST_PSEUDO_REGISTER
)
577 rtx reg
= DECL_RTL (decl
);
580 for (regno
= REGNO (reg
);
582 + hard_regno_nregs
[REGNO (reg
)][GET_MODE (reg
)]);
584 if (TEST_HARD_REG_BIT (*regs
, regno
))
589 else if (TYPE_P (decl
))
594 /* If there is an overlap between *REGS and DECL, return the first overlap
597 tree_overlaps_hard_reg_set (tree decl
, HARD_REG_SET
*regs
)
599 return walk_tree (&decl
, decl_overlaps_hard_reg_set_p
, regs
, NULL
);
602 /* Check for overlap between registers marked in CLOBBERED_REGS and
603 anything inappropriate in T. Emit error and return the register
604 variable definition for error, NULL_TREE for ok. */
607 tree_conflicts_with_clobbers_p (tree t
, HARD_REG_SET
*clobbered_regs
)
609 /* Conflicts between asm-declared register variables and the clobber
610 list are not allowed. */
611 tree overlap
= tree_overlaps_hard_reg_set (t
, clobbered_regs
);
615 error ("asm-specifier for variable %qs conflicts with asm clobber list",
616 IDENTIFIER_POINTER (DECL_NAME (overlap
)));
618 /* Reset registerness to stop multiple errors emitted for a single
620 DECL_REGISTER (overlap
) = 0;
627 /* Generate RTL for an asm statement with arguments.
628 STRING is the instruction template.
629 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
630 Each output or input has an expression in the TREE_VALUE and
631 and a tree list in TREE_PURPOSE which in turn contains a constraint
632 name in TREE_VALUE (or NULL_TREE) and a constraint string
634 CLOBBERS is a list of STRING_CST nodes each naming a hard register
635 that is clobbered by this insn.
637 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
638 Some elements of OUTPUTS may be replaced with trees representing temporary
639 values. The caller should copy those temporary values to the originally
642 VOL nonzero means the insn is volatile; don't optimize it. */
645 expand_asm_operands (tree string
, tree outputs
, tree inputs
,
646 tree clobbers
, int vol
, location_t locus
)
648 rtvec argvec
, constraintvec
;
650 int ninputs
= list_length (inputs
);
651 int noutputs
= list_length (outputs
);
654 HARD_REG_SET clobbered_regs
;
655 int clobber_conflict_found
= 0;
659 /* Vector of RTX's of evaluated output operands. */
660 rtx
*output_rtx
= alloca (noutputs
* sizeof (rtx
));
661 int *inout_opnum
= alloca (noutputs
* sizeof (int));
662 rtx
*real_output_rtx
= alloca (noutputs
* sizeof (rtx
));
663 enum machine_mode
*inout_mode
664 = alloca (noutputs
* sizeof (enum machine_mode
));
665 const char **constraints
666 = alloca ((noutputs
+ ninputs
) * sizeof (const char *));
667 int old_generating_concat_p
= generating_concat_p
;
669 /* An ASM with no outputs needs to be treated as volatile, for now. */
673 if (! check_operand_nalternatives (outputs
, inputs
))
676 string
= resolve_asm_operand_names (string
, outputs
, inputs
);
678 /* Collect constraints. */
680 for (t
= outputs
; t
; t
= TREE_CHAIN (t
), i
++)
681 constraints
[i
] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t
)));
682 for (t
= inputs
; t
; t
= TREE_CHAIN (t
), i
++)
683 constraints
[i
] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t
)));
685 /* Sometimes we wish to automatically clobber registers across an asm.
686 Case in point is when the i386 backend moved from cc0 to a hard reg --
687 maintaining source-level compatibility means automatically clobbering
688 the flags register. */
689 clobbers
= targetm
.md_asm_clobbers (outputs
, inputs
, clobbers
);
691 /* Count the number of meaningful clobbered registers, ignoring what
692 we would ignore later. */
694 CLEAR_HARD_REG_SET (clobbered_regs
);
695 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
697 const char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
699 i
= decode_reg_name (regname
);
700 if (i
>= 0 || i
== -4)
703 error ("unknown register name %qs in %<asm%>", regname
);
705 /* Mark clobbered registers. */
708 /* Clobbering the PIC register is an error. */
709 if (i
== (int) PIC_OFFSET_TABLE_REGNUM
)
711 error ("PIC register %qs clobbered in %<asm%>", regname
);
715 SET_HARD_REG_BIT (clobbered_regs
, i
);
719 /* First pass over inputs and outputs checks validity and sets
720 mark_addressable if needed. */
723 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
725 tree val
= TREE_VALUE (tail
);
726 tree type
= TREE_TYPE (val
);
727 const char *constraint
;
732 /* If there's an erroneous arg, emit no insn. */
733 if (type
== error_mark_node
)
736 /* Try to parse the output constraint. If that fails, there's
737 no point in going further. */
738 constraint
= constraints
[i
];
739 if (!parse_output_constraint (&constraint
, i
, ninputs
, noutputs
,
740 &allows_mem
, &allows_reg
, &is_inout
))
747 && REG_P (DECL_RTL (val
))
748 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
))))
749 lang_hooks
.mark_addressable (val
);
756 if (ninputs
+ noutputs
> MAX_RECOG_OPERANDS
)
758 error ("more than %d operands in %<asm%>", MAX_RECOG_OPERANDS
);
762 for (i
= 0, tail
= inputs
; tail
; i
++, tail
= TREE_CHAIN (tail
))
764 bool allows_reg
, allows_mem
;
765 const char *constraint
;
767 /* If there's an erroneous arg, emit no insn, because the ASM_INPUT
768 would get VOIDmode and that could cause a crash in reload. */
769 if (TREE_TYPE (TREE_VALUE (tail
)) == error_mark_node
)
772 constraint
= constraints
[i
+ noutputs
];
773 if (! parse_input_constraint (&constraint
, i
, ninputs
, noutputs
, ninout
,
774 constraints
, &allows_mem
, &allows_reg
))
777 if (! allows_reg
&& allows_mem
)
778 lang_hooks
.mark_addressable (TREE_VALUE (tail
));
781 /* Second pass evaluates arguments. */
784 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
786 tree val
= TREE_VALUE (tail
);
787 tree type
= TREE_TYPE (val
);
794 ok
= parse_output_constraint (&constraints
[i
], i
, ninputs
,
795 noutputs
, &allows_mem
, &allows_reg
,
799 /* If an output operand is not a decl or indirect ref and our constraint
800 allows a register, make a temporary to act as an intermediate.
801 Make the asm insn write into that, then our caller will copy it to
802 the real output operand. Likewise for promoted variables. */
804 generating_concat_p
= 0;
806 real_output_rtx
[i
] = NULL_RTX
;
807 if ((TREE_CODE (val
) == INDIRECT_REF
810 && (allows_mem
|| REG_P (DECL_RTL (val
)))
811 && ! (REG_P (DECL_RTL (val
))
812 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
)))
816 op
= expand_expr (val
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
818 op
= validize_mem (op
);
820 if (! allows_reg
&& !MEM_P (op
))
821 error ("output number %d not directly addressable", i
);
822 if ((! allows_mem
&& MEM_P (op
))
823 || GET_CODE (op
) == CONCAT
)
825 real_output_rtx
[i
] = op
;
826 op
= gen_reg_rtx (GET_MODE (op
));
828 emit_move_insn (op
, real_output_rtx
[i
]);
833 op
= assign_temp (type
, 0, 0, 1);
834 op
= validize_mem (op
);
835 TREE_VALUE (tail
) = make_tree (type
, op
);
839 generating_concat_p
= old_generating_concat_p
;
843 inout_mode
[ninout
] = TYPE_MODE (type
);
844 inout_opnum
[ninout
++] = i
;
847 if (tree_conflicts_with_clobbers_p (val
, &clobbered_regs
))
848 clobber_conflict_found
= 1;
851 /* Make vectors for the expression-rtx, constraint strings,
852 and named operands. */
854 argvec
= rtvec_alloc (ninputs
);
855 constraintvec
= rtvec_alloc (ninputs
);
857 body
= gen_rtx_ASM_OPERANDS ((noutputs
== 0 ? VOIDmode
858 : GET_MODE (output_rtx
[0])),
859 ggc_strdup (TREE_STRING_POINTER (string
)),
860 empty_string
, 0, argvec
, constraintvec
,
863 MEM_VOLATILE_P (body
) = vol
;
865 /* Eval the inputs and put them into ARGVEC.
866 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
868 for (i
= 0, tail
= inputs
; tail
; tail
= TREE_CHAIN (tail
), ++i
)
870 bool allows_reg
, allows_mem
;
871 const char *constraint
;
876 constraint
= constraints
[i
+ noutputs
];
877 ok
= parse_input_constraint (&constraint
, i
, ninputs
, noutputs
, ninout
,
878 constraints
, &allows_mem
, &allows_reg
);
881 generating_concat_p
= 0;
883 val
= TREE_VALUE (tail
);
884 type
= TREE_TYPE (val
);
885 op
= expand_expr (val
, NULL_RTX
, VOIDmode
,
886 (allows_mem
&& !allows_reg
887 ? EXPAND_MEMORY
: EXPAND_NORMAL
));
889 /* Never pass a CONCAT to an ASM. */
890 if (GET_CODE (op
) == CONCAT
)
891 op
= force_reg (GET_MODE (op
), op
);
893 op
= validize_mem (op
);
895 if (asm_operand_ok (op
, constraint
) <= 0)
897 if (allows_reg
&& TYPE_MODE (type
) != BLKmode
)
898 op
= force_reg (TYPE_MODE (type
), op
);
899 else if (!allows_mem
)
900 warning (0, "asm operand %d probably doesn%'t match constraints",
904 /* We won't recognize either volatile memory or memory
905 with a queued address as available a memory_operand
906 at this point. Ignore it: clearly this *is* a memory. */
910 warning (0, "use of memory input without lvalue in "
911 "asm operand %d is deprecated", i
+ noutputs
);
915 rtx mem
= force_const_mem (TYPE_MODE (type
), op
);
917 op
= validize_mem (mem
);
919 op
= force_reg (TYPE_MODE (type
), op
);
922 || GET_CODE (op
) == SUBREG
923 || GET_CODE (op
) == CONCAT
)
925 tree qual_type
= build_qualified_type (type
,
928 rtx memloc
= assign_temp (qual_type
, 1, 1, 1);
929 memloc
= validize_mem (memloc
);
930 emit_move_insn (memloc
, op
);
936 generating_concat_p
= old_generating_concat_p
;
937 ASM_OPERANDS_INPUT (body
, i
) = op
;
939 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body
, i
)
940 = gen_rtx_ASM_INPUT (TYPE_MODE (type
),
941 ggc_strdup (constraints
[i
+ noutputs
]));
943 if (tree_conflicts_with_clobbers_p (val
, &clobbered_regs
))
944 clobber_conflict_found
= 1;
947 /* Protect all the operands from the queue now that they have all been
950 generating_concat_p
= 0;
952 /* For in-out operands, copy output rtx to input rtx. */
953 for (i
= 0; i
< ninout
; i
++)
955 int j
= inout_opnum
[i
];
958 ASM_OPERANDS_INPUT (body
, ninputs
- ninout
+ i
)
961 sprintf (buffer
, "%d", j
);
962 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body
, ninputs
- ninout
+ i
)
963 = gen_rtx_ASM_INPUT (inout_mode
[i
], ggc_strdup (buffer
));
966 generating_concat_p
= old_generating_concat_p
;
968 /* Now, for each output, construct an rtx
969 (set OUTPUT (asm_operands INSN OUTPUTCONSTRAINT OUTPUTNUMBER
970 ARGVEC CONSTRAINTS OPNAMES))
971 If there is more than one, put them inside a PARALLEL. */
973 if (noutputs
== 1 && nclobbers
== 0)
975 ASM_OPERANDS_OUTPUT_CONSTRAINT (body
) = ggc_strdup (constraints
[0]);
976 emit_insn (gen_rtx_SET (VOIDmode
, output_rtx
[0], body
));
979 else if (noutputs
== 0 && nclobbers
== 0)
981 /* No output operands: put in a raw ASM_OPERANDS rtx. */
993 body
= gen_rtx_PARALLEL (VOIDmode
, rtvec_alloc (num
+ nclobbers
));
995 /* For each output operand, store a SET. */
996 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
999 = gen_rtx_SET (VOIDmode
,
1001 gen_rtx_ASM_OPERANDS
1002 (GET_MODE (output_rtx
[i
]),
1003 ggc_strdup (TREE_STRING_POINTER (string
)),
1004 ggc_strdup (constraints
[i
]),
1005 i
, argvec
, constraintvec
, locus
));
1007 MEM_VOLATILE_P (SET_SRC (XVECEXP (body
, 0, i
))) = vol
;
1010 /* If there are no outputs (but there are some clobbers)
1011 store the bare ASM_OPERANDS into the PARALLEL. */
1014 XVECEXP (body
, 0, i
++) = obody
;
1016 /* Store (clobber REG) for each clobbered register specified. */
1018 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1020 const char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1021 int j
= decode_reg_name (regname
);
1026 if (j
== -3) /* `cc', which is not a register */
1029 if (j
== -4) /* `memory', don't cache memory across asm */
1031 XVECEXP (body
, 0, i
++)
1032 = gen_rtx_CLOBBER (VOIDmode
,
1035 gen_rtx_SCRATCH (VOIDmode
)));
1039 /* Ignore unknown register, error already signaled. */
1043 /* Use QImode since that's guaranteed to clobber just one reg. */
1044 clobbered_reg
= gen_rtx_REG (QImode
, j
);
1046 /* Do sanity check for overlap between clobbers and respectively
1047 input and outputs that hasn't been handled. Such overlap
1048 should have been detected and reported above. */
1049 if (!clobber_conflict_found
)
1053 /* We test the old body (obody) contents to avoid tripping
1054 over the under-construction body. */
1055 for (opno
= 0; opno
< noutputs
; opno
++)
1056 if (reg_overlap_mentioned_p (clobbered_reg
, output_rtx
[opno
]))
1057 internal_error ("asm clobber conflict with output operand");
1059 for (opno
= 0; opno
< ninputs
- ninout
; opno
++)
1060 if (reg_overlap_mentioned_p (clobbered_reg
,
1061 ASM_OPERANDS_INPUT (obody
, opno
)))
1062 internal_error ("asm clobber conflict with input operand");
1065 XVECEXP (body
, 0, i
++)
1066 = gen_rtx_CLOBBER (VOIDmode
, clobbered_reg
);
1072 /* For any outputs that needed reloading into registers, spill them
1073 back to where they belong. */
1074 for (i
= 0; i
< noutputs
; ++i
)
1075 if (real_output_rtx
[i
])
1076 emit_move_insn (real_output_rtx
[i
], output_rtx
[i
]);
1082 expand_asm_expr (tree exp
)
1088 if (ASM_INPUT_P (exp
))
1090 expand_asm (ASM_STRING (exp
), ASM_VOLATILE_P (exp
));
1094 outputs
= ASM_OUTPUTS (exp
);
1095 noutputs
= list_length (outputs
);
1096 /* o[I] is the place that output number I should be written. */
1097 o
= (tree
*) alloca (noutputs
* sizeof (tree
));
1099 /* Record the contents of OUTPUTS before it is modified. */
1100 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1101 o
[i
] = TREE_VALUE (tail
);
1103 /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
1104 OUTPUTS some trees for where the values were actually stored. */
1105 expand_asm_operands (ASM_STRING (exp
), outputs
, ASM_INPUTS (exp
),
1106 ASM_CLOBBERS (exp
), ASM_VOLATILE_P (exp
),
1109 /* Copy all the intermediate outputs into the specified outputs. */
1110 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1112 if (o
[i
] != TREE_VALUE (tail
))
1114 expand_assignment (o
[i
], TREE_VALUE (tail
));
1117 /* Restore the original value so that it's correct the next
1118 time we expand this function. */
1119 TREE_VALUE (tail
) = o
[i
];
1124 /* A subroutine of expand_asm_operands. Check that all operands have
1125 the same number of alternatives. Return true if so. */
1128 check_operand_nalternatives (tree outputs
, tree inputs
)
1130 if (outputs
|| inputs
)
1132 tree tmp
= TREE_PURPOSE (outputs
? outputs
: inputs
);
1134 = n_occurrences (',', TREE_STRING_POINTER (TREE_VALUE (tmp
)));
1137 if (nalternatives
+ 1 > MAX_RECOG_ALTERNATIVES
)
1139 error ("too many alternatives in %<asm%>");
1146 const char *constraint
1147 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tmp
)));
1149 if (n_occurrences (',', constraint
) != nalternatives
)
1151 error ("operand constraints for %<asm%> differ "
1152 "in number of alternatives");
1156 if (TREE_CHAIN (tmp
))
1157 tmp
= TREE_CHAIN (tmp
);
1159 tmp
= next
, next
= 0;
1166 /* A subroutine of expand_asm_operands. Check that all operand names
1167 are unique. Return true if so. We rely on the fact that these names
1168 are identifiers, and so have been canonicalized by get_identifier,
1169 so all we need are pointer comparisons. */
1172 check_unique_operand_names (tree outputs
, tree inputs
)
1176 for (i
= outputs
; i
; i
= TREE_CHAIN (i
))
1178 tree i_name
= TREE_PURPOSE (TREE_PURPOSE (i
));
1182 for (j
= TREE_CHAIN (i
); j
; j
= TREE_CHAIN (j
))
1183 if (simple_cst_equal (i_name
, TREE_PURPOSE (TREE_PURPOSE (j
))))
1187 for (i
= inputs
; i
; i
= TREE_CHAIN (i
))
1189 tree i_name
= TREE_PURPOSE (TREE_PURPOSE (i
));
1193 for (j
= TREE_CHAIN (i
); j
; j
= TREE_CHAIN (j
))
1194 if (simple_cst_equal (i_name
, TREE_PURPOSE (TREE_PURPOSE (j
))))
1196 for (j
= outputs
; j
; j
= TREE_CHAIN (j
))
1197 if (simple_cst_equal (i_name
, TREE_PURPOSE (TREE_PURPOSE (j
))))
1204 error ("duplicate asm operand name %qs",
1205 TREE_STRING_POINTER (TREE_PURPOSE (TREE_PURPOSE (i
))));
1209 /* A subroutine of expand_asm_operands. Resolve the names of the operands
1210 in *POUTPUTS and *PINPUTS to numbers, and replace the name expansions in
1211 STRING and in the constraints to those numbers. */
1214 resolve_asm_operand_names (tree string
, tree outputs
, tree inputs
)
1221 check_unique_operand_names (outputs
, inputs
);
1223 /* Substitute [<name>] in input constraint strings. There should be no
1224 named operands in output constraints. */
1225 for (t
= inputs
; t
; t
= TREE_CHAIN (t
))
1227 c
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t
)));
1228 if (strchr (c
, '[') != NULL
)
1230 p
= buffer
= xstrdup (c
);
1231 while ((p
= strchr (p
, '[')) != NULL
)
1232 p
= resolve_operand_name_1 (p
, outputs
, inputs
);
1233 TREE_VALUE (TREE_PURPOSE (t
))
1234 = build_string (strlen (buffer
), buffer
);
1239 /* Now check for any needed substitutions in the template. */
1240 c
= TREE_STRING_POINTER (string
);
1241 while ((c
= strchr (c
, '%')) != NULL
)
1245 else if (ISALPHA (c
[1]) && c
[2] == '[')
1256 /* OK, we need to make a copy so we can perform the substitutions.
1257 Assume that we will not need extra space--we get to remove '['
1258 and ']', which means we cannot have a problem until we have more
1259 than 999 operands. */
1260 buffer
= xstrdup (TREE_STRING_POINTER (string
));
1261 p
= buffer
+ (c
- TREE_STRING_POINTER (string
));
1263 while ((p
= strchr (p
, '%')) != NULL
)
1267 else if (ISALPHA (p
[1]) && p
[2] == '[')
1275 p
= resolve_operand_name_1 (p
, outputs
, inputs
);
1278 string
= build_string (strlen (buffer
), buffer
);
1285 /* A subroutine of resolve_operand_names. P points to the '[' for a
1286 potential named operand of the form [<name>]. In place, replace
1287 the name and brackets with a number. Return a pointer to the
1288 balance of the string after substitution. */
1291 resolve_operand_name_1 (char *p
, tree outputs
, tree inputs
)
1298 /* Collect the operand name. */
1299 q
= strchr (p
, ']');
1302 error ("missing close brace for named operand");
1303 return strchr (p
, '\0');
1307 /* Resolve the name to a number. */
1308 for (op
= 0, t
= outputs
; t
; t
= TREE_CHAIN (t
), op
++)
1310 tree name
= TREE_PURPOSE (TREE_PURPOSE (t
));
1313 const char *c
= TREE_STRING_POINTER (name
);
1314 if (strncmp (c
, p
+ 1, len
) == 0 && c
[len
] == '\0')
1318 for (t
= inputs
; t
; t
= TREE_CHAIN (t
), op
++)
1320 tree name
= TREE_PURPOSE (TREE_PURPOSE (t
));
1323 const char *c
= TREE_STRING_POINTER (name
);
1324 if (strncmp (c
, p
+ 1, len
) == 0 && c
[len
] == '\0')
1330 error ("undefined named operand %qs", p
+ 1);
1334 /* Replace the name with the number. Unfortunately, not all libraries
1335 get the return value of sprintf correct, so search for the end of the
1336 generated string by hand. */
1337 sprintf (p
, "%d", op
);
1338 p
= strchr (p
, '\0');
1340 /* Verify the no extra buffer space assumption. */
1341 gcc_assert (p
<= q
);
1343 /* Shift the rest of the buffer down to fill the gap. */
1344 memmove (p
, q
+ 1, strlen (q
+ 1) + 1);
1349 /* Generate RTL to evaluate the expression EXP. */
1352 expand_expr_stmt (tree exp
)
1357 value
= expand_expr (exp
, const0_rtx
, VOIDmode
, 0);
1358 type
= TREE_TYPE (exp
);
1360 /* If all we do is reference a volatile value in memory,
1361 copy it to a register to be sure it is actually touched. */
1362 if (value
&& MEM_P (value
) && TREE_THIS_VOLATILE (exp
))
1364 if (TYPE_MODE (type
) == VOIDmode
)
1366 else if (TYPE_MODE (type
) != BLKmode
)
1367 value
= copy_to_reg (value
);
1370 rtx lab
= gen_label_rtx ();
1372 /* Compare the value with itself to reference it. */
1373 emit_cmp_and_jump_insns (value
, value
, EQ
,
1374 expand_normal (TYPE_SIZE (type
)),
1380 /* Free any temporaries used to evaluate this expression. */
1384 /* Warn if EXP contains any computations whose results are not used.
1385 Return 1 if a warning is printed; 0 otherwise. LOCUS is the
1386 (potential) location of the expression. */
1389 warn_if_unused_value (tree exp
, location_t locus
)
1392 if (TREE_USED (exp
) || TREE_NO_WARNING (exp
))
1395 /* Don't warn about void constructs. This includes casting to void,
1396 void function calls, and statement expressions with a final cast
1398 if (VOID_TYPE_P (TREE_TYPE (exp
)))
1401 if (EXPR_HAS_LOCATION (exp
))
1402 locus
= EXPR_LOCATION (exp
);
1404 switch (TREE_CODE (exp
))
1406 case PREINCREMENT_EXPR
:
1407 case POSTINCREMENT_EXPR
:
1408 case PREDECREMENT_EXPR
:
1409 case POSTDECREMENT_EXPR
:
1414 case TRY_CATCH_EXPR
:
1415 case WITH_CLEANUP_EXPR
:
1420 /* For a binding, warn if no side effect within it. */
1421 exp
= BIND_EXPR_BODY (exp
);
1425 exp
= TREE_OPERAND (exp
, 0);
1428 case TRUTH_ORIF_EXPR
:
1429 case TRUTH_ANDIF_EXPR
:
1430 /* In && or ||, warn if 2nd operand has no side effect. */
1431 exp
= TREE_OPERAND (exp
, 1);
1435 if (warn_if_unused_value (TREE_OPERAND (exp
, 0), locus
))
1437 /* Let people do `(foo (), 0)' without a warning. */
1438 if (TREE_CONSTANT (TREE_OPERAND (exp
, 1)))
1440 exp
= TREE_OPERAND (exp
, 1);
1444 /* If this is an expression with side effects, don't warn; this
1445 case commonly appears in macro expansions. */
1446 if (TREE_SIDE_EFFECTS (exp
))
1451 /* Don't warn about automatic dereferencing of references, since
1452 the user cannot control it. */
1453 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp
, 0))) == REFERENCE_TYPE
)
1455 exp
= TREE_OPERAND (exp
, 0);
1461 /* Referencing a volatile value is a side effect, so don't warn. */
1462 if ((DECL_P (exp
) || REFERENCE_CLASS_P (exp
))
1463 && TREE_THIS_VOLATILE (exp
))
1466 /* If this is an expression which has no operands, there is no value
1467 to be unused. There are no such language-independent codes,
1468 but front ends may define such. */
1469 if (EXPRESSION_CLASS_P (exp
) && TREE_CODE_LENGTH (TREE_CODE (exp
)) == 0)
1473 warning (0, "%Hvalue computed is not used", &locus
);
1479 /* Generate RTL to return from the current function, with no value.
1480 (That is, we do not do anything about returning any value.) */
1483 expand_null_return (void)
1485 /* If this function was declared to return a value, but we
1486 didn't, clobber the return registers so that they are not
1487 propagated live to the rest of the function. */
1488 clobber_return_register ();
1490 expand_null_return_1 ();
1493 /* Generate RTL to return directly from the current function.
1494 (That is, we bypass any return value.) */
1497 expand_naked_return (void)
1501 clear_pending_stack_adjust ();
1502 do_pending_stack_adjust ();
1504 end_label
= naked_return_label
;
1506 end_label
= naked_return_label
= gen_label_rtx ();
1508 emit_jump (end_label
);
1511 /* Generate RTL to return from the current function, with value VAL. */
1514 expand_value_return (rtx val
)
1516 /* Copy the value to the return location
1517 unless it's already there. */
1519 rtx return_reg
= DECL_RTL (DECL_RESULT (current_function_decl
));
1520 if (return_reg
!= val
)
1522 tree type
= TREE_TYPE (DECL_RESULT (current_function_decl
));
1523 if (targetm
.calls
.promote_function_return (TREE_TYPE (current_function_decl
)))
1525 int unsignedp
= TYPE_UNSIGNED (type
);
1526 enum machine_mode old_mode
1527 = DECL_MODE (DECL_RESULT (current_function_decl
));
1528 enum machine_mode mode
1529 = promote_mode (type
, old_mode
, &unsignedp
, 1);
1531 if (mode
!= old_mode
)
1532 val
= convert_modes (mode
, old_mode
, val
, unsignedp
);
1534 if (GET_CODE (return_reg
) == PARALLEL
)
1535 emit_group_load (return_reg
, val
, type
, int_size_in_bytes (type
));
1537 emit_move_insn (return_reg
, val
);
1540 expand_null_return_1 ();
1543 /* Output a return with no value. */
1546 expand_null_return_1 (void)
1548 clear_pending_stack_adjust ();
1549 do_pending_stack_adjust ();
1550 emit_jump (return_label
);
1553 /* Generate RTL to evaluate the expression RETVAL and return it
1554 from the current function. */
1557 expand_return (tree retval
)
1563 /* If function wants no value, give it none. */
1564 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl
))) == VOID_TYPE
)
1566 expand_normal (retval
);
1567 expand_null_return ();
1571 if (retval
== error_mark_node
)
1573 /* Treat this like a return of no value from a function that
1575 expand_null_return ();
1578 else if ((TREE_CODE (retval
) == MODIFY_EXPR
1579 || TREE_CODE (retval
) == INIT_EXPR
)
1580 && TREE_CODE (TREE_OPERAND (retval
, 0)) == RESULT_DECL
)
1581 retval_rhs
= TREE_OPERAND (retval
, 1);
1583 retval_rhs
= retval
;
1585 result_rtl
= DECL_RTL (DECL_RESULT (current_function_decl
));
1587 /* If we are returning the RESULT_DECL, then the value has already
1588 been stored into it, so we don't have to do anything special. */
1589 if (TREE_CODE (retval_rhs
) == RESULT_DECL
)
1590 expand_value_return (result_rtl
);
1592 /* If the result is an aggregate that is being returned in one (or more)
1593 registers, load the registers here. The compiler currently can't handle
1594 copying a BLKmode value into registers. We could put this code in a
1595 more general area (for use by everyone instead of just function
1596 call/return), but until this feature is generally usable it is kept here
1597 (and in expand_call). */
1599 else if (retval_rhs
!= 0
1600 && TYPE_MODE (TREE_TYPE (retval_rhs
)) == BLKmode
1601 && REG_P (result_rtl
))
1604 unsigned HOST_WIDE_INT bitpos
, xbitpos
;
1605 unsigned HOST_WIDE_INT padding_correction
= 0;
1606 unsigned HOST_WIDE_INT bytes
1607 = int_size_in_bytes (TREE_TYPE (retval_rhs
));
1608 int n_regs
= (bytes
+ UNITS_PER_WORD
- 1) / UNITS_PER_WORD
;
1609 unsigned int bitsize
1610 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs
)), BITS_PER_WORD
);
1611 rtx
*result_pseudos
= alloca (sizeof (rtx
) * n_regs
);
1612 rtx result_reg
, src
= NULL_RTX
, dst
= NULL_RTX
;
1613 rtx result_val
= expand_normal (retval_rhs
);
1614 enum machine_mode tmpmode
, result_reg_mode
;
1618 expand_null_return ();
1622 /* If the structure doesn't take up a whole number of words, see
1623 whether the register value should be padded on the left or on
1624 the right. Set PADDING_CORRECTION to the number of padding
1625 bits needed on the left side.
1627 In most ABIs, the structure will be returned at the least end of
1628 the register, which translates to right padding on little-endian
1629 targets and left padding on big-endian targets. The opposite
1630 holds if the structure is returned at the most significant
1631 end of the register. */
1632 if (bytes
% UNITS_PER_WORD
!= 0
1633 && (targetm
.calls
.return_in_msb (TREE_TYPE (retval_rhs
))
1635 : BYTES_BIG_ENDIAN
))
1636 padding_correction
= (BITS_PER_WORD
- ((bytes
% UNITS_PER_WORD
)
1639 /* Copy the structure BITSIZE bits at a time. */
1640 for (bitpos
= 0, xbitpos
= padding_correction
;
1641 bitpos
< bytes
* BITS_PER_UNIT
;
1642 bitpos
+= bitsize
, xbitpos
+= bitsize
)
1644 /* We need a new destination pseudo each time xbitpos is
1645 on a word boundary and when xbitpos == padding_correction
1646 (the first time through). */
1647 if (xbitpos
% BITS_PER_WORD
== 0
1648 || xbitpos
== padding_correction
)
1650 /* Generate an appropriate register. */
1651 dst
= gen_reg_rtx (word_mode
);
1652 result_pseudos
[xbitpos
/ BITS_PER_WORD
] = dst
;
1654 /* Clear the destination before we move anything into it. */
1655 emit_move_insn (dst
, CONST0_RTX (GET_MODE (dst
)));
1658 /* We need a new source operand each time bitpos is on a word
1660 if (bitpos
% BITS_PER_WORD
== 0)
1661 src
= operand_subword_force (result_val
,
1662 bitpos
/ BITS_PER_WORD
,
1665 /* Use bitpos for the source extraction (left justified) and
1666 xbitpos for the destination store (right justified). */
1667 store_bit_field (dst
, bitsize
, xbitpos
% BITS_PER_WORD
, word_mode
,
1668 extract_bit_field (src
, bitsize
,
1669 bitpos
% BITS_PER_WORD
, 1,
1670 NULL_RTX
, word_mode
, word_mode
));
1673 tmpmode
= GET_MODE (result_rtl
);
1674 if (tmpmode
== BLKmode
)
1676 /* Find the smallest integer mode large enough to hold the
1677 entire structure and use that mode instead of BLKmode
1678 on the USE insn for the return register. */
1679 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
1680 tmpmode
!= VOIDmode
;
1681 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
1682 /* Have we found a large enough mode? */
1683 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
1686 /* A suitable mode should have been found. */
1687 gcc_assert (tmpmode
!= VOIDmode
);
1689 PUT_MODE (result_rtl
, tmpmode
);
1692 if (GET_MODE_SIZE (tmpmode
) < GET_MODE_SIZE (word_mode
))
1693 result_reg_mode
= word_mode
;
1695 result_reg_mode
= tmpmode
;
1696 result_reg
= gen_reg_rtx (result_reg_mode
);
1698 for (i
= 0; i
< n_regs
; i
++)
1699 emit_move_insn (operand_subword (result_reg
, i
, 0, result_reg_mode
),
1702 if (tmpmode
!= result_reg_mode
)
1703 result_reg
= gen_lowpart (tmpmode
, result_reg
);
1705 expand_value_return (result_reg
);
1707 else if (retval_rhs
!= 0
1708 && !VOID_TYPE_P (TREE_TYPE (retval_rhs
))
1709 && (REG_P (result_rtl
)
1710 || (GET_CODE (result_rtl
) == PARALLEL
)))
1712 /* Calculate the return value into a temporary (usually a pseudo
1714 tree ot
= TREE_TYPE (DECL_RESULT (current_function_decl
));
1715 tree nt
= build_qualified_type (ot
, TYPE_QUALS (ot
) | TYPE_QUAL_CONST
);
1717 val
= assign_temp (nt
, 0, 0, 1);
1718 val
= expand_expr (retval_rhs
, val
, GET_MODE (val
), 0);
1719 val
= force_not_mem (val
);
1720 /* Return the calculated value. */
1721 expand_value_return (val
);
1725 /* No hard reg used; calculate value into hard return reg. */
1726 expand_expr (retval
, const0_rtx
, VOIDmode
, 0);
1727 expand_value_return (result_rtl
);
1731 /* Given a pointer to a BLOCK node return nonzero if (and only if) the node
1732 in question represents the outermost pair of curly braces (i.e. the "body
1733 block") of a function or method.
1735 For any BLOCK node representing a "body block" of a function or method, the
1736 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
1737 represents the outermost (function) scope for the function or method (i.e.
1738 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
1739 *that* node in turn will point to the relevant FUNCTION_DECL node. */
1742 is_body_block (tree stmt
)
1744 if (lang_hooks
.no_body_blocks
)
1747 if (TREE_CODE (stmt
) == BLOCK
)
1749 tree parent
= BLOCK_SUPERCONTEXT (stmt
);
1751 if (parent
&& TREE_CODE (parent
) == BLOCK
)
1753 tree grandparent
= BLOCK_SUPERCONTEXT (parent
);
1755 if (grandparent
&& TREE_CODE (grandparent
) == FUNCTION_DECL
)
1763 /* Emit code to restore vital registers at the beginning of a nonlocal goto
1766 expand_nl_goto_receiver (void)
1768 /* Clobber the FP when we get here, so we have to make sure it's
1769 marked as used by this function. */
1770 emit_insn (gen_rtx_USE (VOIDmode
, hard_frame_pointer_rtx
));
1772 /* Mark the static chain as clobbered here so life information
1773 doesn't get messed up for it. */
1774 emit_insn (gen_rtx_CLOBBER (VOIDmode
, static_chain_rtx
));
1776 #ifdef HAVE_nonlocal_goto
1777 if (! HAVE_nonlocal_goto
)
1779 /* First adjust our frame pointer to its actual value. It was
1780 previously set to the start of the virtual area corresponding to
1781 the stacked variables when we branched here and now needs to be
1782 adjusted to the actual hardware fp value.
1784 Assignments are to virtual registers are converted by
1785 instantiate_virtual_regs into the corresponding assignment
1786 to the underlying register (fp in this case) that makes
1787 the original assignment true.
1788 So the following insn will actually be
1789 decrementing fp by STARTING_FRAME_OFFSET. */
1790 emit_move_insn (virtual_stack_vars_rtx
, hard_frame_pointer_rtx
);
1792 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
1793 if (fixed_regs
[ARG_POINTER_REGNUM
])
1795 #ifdef ELIMINABLE_REGS
1796 /* If the argument pointer can be eliminated in favor of the
1797 frame pointer, we don't need to restore it. We assume here
1798 that if such an elimination is present, it can always be used.
1799 This is the case on all known machines; if we don't make this
1800 assumption, we do unnecessary saving on many machines. */
1801 static const struct elims
{const int from
, to
;} elim_regs
[] = ELIMINABLE_REGS
;
1804 for (i
= 0; i
< ARRAY_SIZE (elim_regs
); i
++)
1805 if (elim_regs
[i
].from
== ARG_POINTER_REGNUM
1806 && elim_regs
[i
].to
== HARD_FRAME_POINTER_REGNUM
)
1809 if (i
== ARRAY_SIZE (elim_regs
))
1812 /* Now restore our arg pointer from the address at which it
1813 was saved in our stack frame. */
1814 emit_move_insn (virtual_incoming_args_rtx
,
1815 copy_to_reg (get_arg_pointer_save_area (cfun
)));
1820 #ifdef HAVE_nonlocal_goto_receiver
1821 if (HAVE_nonlocal_goto_receiver
)
1822 emit_insn (gen_nonlocal_goto_receiver ());
1825 /* @@@ This is a kludge. Not all machine descriptions define a blockage
1826 insn, but we must not allow the code we just generated to be reordered
1827 by scheduling. Specifically, the update of the frame pointer must
1828 happen immediately, not later. So emit an ASM_INPUT to act as blockage
1830 emit_insn (gen_rtx_ASM_INPUT (VOIDmode
, ""));
1833 /* Generate RTL for the automatic variable declaration DECL.
1834 (Other kinds of declarations are simply ignored if seen here.) */
1837 expand_decl (tree decl
)
1841 type
= TREE_TYPE (decl
);
1843 /* For a CONST_DECL, set mode, alignment, and sizes from those of the
1844 type in case this node is used in a reference. */
1845 if (TREE_CODE (decl
) == CONST_DECL
)
1847 DECL_MODE (decl
) = TYPE_MODE (type
);
1848 DECL_ALIGN (decl
) = TYPE_ALIGN (type
);
1849 DECL_SIZE (decl
) = TYPE_SIZE (type
);
1850 DECL_SIZE_UNIT (decl
) = TYPE_SIZE_UNIT (type
);
1854 /* Otherwise, only automatic variables need any expansion done. Static and
1855 external variables, and external functions, will be handled by
1856 `assemble_variable' (called from finish_decl). TYPE_DECL requires
1857 nothing. PARM_DECLs are handled in `assign_parms'. */
1858 if (TREE_CODE (decl
) != VAR_DECL
)
1861 if (TREE_STATIC (decl
) || DECL_EXTERNAL (decl
))
1864 /* Create the RTL representation for the variable. */
1866 if (type
== error_mark_node
)
1867 SET_DECL_RTL (decl
, gen_rtx_MEM (BLKmode
, const0_rtx
));
1869 else if (DECL_SIZE (decl
) == 0)
1870 /* Variable with incomplete type. */
1873 if (DECL_INITIAL (decl
) == 0)
1874 /* Error message was already done; now avoid a crash. */
1875 x
= gen_rtx_MEM (BLKmode
, const0_rtx
);
1877 /* An initializer is going to decide the size of this array.
1878 Until we know the size, represent its address with a reg. */
1879 x
= gen_rtx_MEM (BLKmode
, gen_reg_rtx (Pmode
));
1881 set_mem_attributes (x
, decl
, 1);
1882 SET_DECL_RTL (decl
, x
);
1884 else if (use_register_for_decl (decl
))
1886 /* Automatic variable that can go in a register. */
1887 int unsignedp
= TYPE_UNSIGNED (type
);
1888 enum machine_mode reg_mode
1889 = promote_mode (type
, DECL_MODE (decl
), &unsignedp
, 0);
1891 SET_DECL_RTL (decl
, gen_reg_rtx (reg_mode
));
1893 /* Note if the object is a user variable. */
1894 if (!DECL_ARTIFICIAL (decl
))
1896 mark_user_reg (DECL_RTL (decl
));
1898 /* Trust user variables which have a pointer type to really
1899 be pointers. Do not trust compiler generated temporaries
1900 as our type system is totally busted as it relates to
1901 pointer arithmetic which translates into lots of compiler
1902 generated objects with pointer types, but which are not really
1904 if (POINTER_TYPE_P (type
))
1905 mark_reg_pointer (DECL_RTL (decl
),
1906 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl
))));
1910 else if (TREE_CODE (DECL_SIZE_UNIT (decl
)) == INTEGER_CST
1911 && ! (flag_stack_check
&& ! STACK_CHECK_BUILTIN
1912 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl
),
1913 STACK_CHECK_MAX_VAR_SIZE
)))
1915 /* Variable of fixed size that goes on the stack. */
1920 /* If we previously made RTL for this decl, it must be an array
1921 whose size was determined by the initializer.
1922 The old address was a register; set that register now
1923 to the proper address. */
1924 if (DECL_RTL_SET_P (decl
))
1926 gcc_assert (MEM_P (DECL_RTL (decl
)));
1927 gcc_assert (REG_P (XEXP (DECL_RTL (decl
), 0)));
1928 oldaddr
= XEXP (DECL_RTL (decl
), 0);
1931 /* Set alignment we actually gave this decl. */
1932 DECL_ALIGN (decl
) = (DECL_MODE (decl
) == BLKmode
? BIGGEST_ALIGNMENT
1933 : GET_MODE_BITSIZE (DECL_MODE (decl
)));
1934 DECL_USER_ALIGN (decl
) = 0;
1936 x
= assign_temp (decl
, 1, 1, 1);
1937 set_mem_attributes (x
, decl
, 1);
1938 SET_DECL_RTL (decl
, x
);
1942 addr
= force_operand (XEXP (DECL_RTL (decl
), 0), oldaddr
);
1943 if (addr
!= oldaddr
)
1944 emit_move_insn (oldaddr
, addr
);
1948 /* Dynamic-size object: must push space on the stack. */
1950 rtx address
, size
, x
;
1952 /* Record the stack pointer on entry to block, if have
1953 not already done so. */
1954 do_pending_stack_adjust ();
1956 /* Compute the variable's size, in bytes. This will expand any
1957 needed SAVE_EXPRs for the first time. */
1958 size
= expand_normal (DECL_SIZE_UNIT (decl
));
1961 /* Allocate space on the stack for the variable. Note that
1962 DECL_ALIGN says how the variable is to be aligned and we
1963 cannot use it to conclude anything about the alignment of
1965 address
= allocate_dynamic_stack_space (size
, NULL_RTX
,
1966 TYPE_ALIGN (TREE_TYPE (decl
)));
1968 /* Reference the variable indirect through that rtx. */
1969 x
= gen_rtx_MEM (DECL_MODE (decl
), address
);
1970 set_mem_attributes (x
, decl
, 1);
1971 SET_DECL_RTL (decl
, x
);
1974 /* Indicate the alignment we actually gave this variable. */
1975 #ifdef STACK_BOUNDARY
1976 DECL_ALIGN (decl
) = STACK_BOUNDARY
;
1978 DECL_ALIGN (decl
) = BIGGEST_ALIGNMENT
;
1980 DECL_USER_ALIGN (decl
) = 0;
1984 /* Emit code to save the current value of stack. */
1986 expand_stack_save (void)
1990 do_pending_stack_adjust ();
1991 emit_stack_save (SAVE_BLOCK
, &ret
, NULL_RTX
);
1995 /* Emit code to restore the current value of stack. */
1997 expand_stack_restore (tree var
)
1999 rtx sa
= DECL_RTL (var
);
2001 emit_stack_restore (SAVE_BLOCK
, sa
, NULL_RTX
);
2004 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
2005 DECL_ELTS is the list of elements that belong to DECL's type.
2006 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
2009 expand_anon_union_decl (tree decl
, tree cleanup ATTRIBUTE_UNUSED
,
2015 /* If any of the elements are addressable, so is the entire union. */
2016 for (t
= decl_elts
; t
; t
= TREE_CHAIN (t
))
2017 if (TREE_ADDRESSABLE (TREE_VALUE (t
)))
2019 TREE_ADDRESSABLE (decl
) = 1;
2024 x
= DECL_RTL (decl
);
2026 /* Go through the elements, assigning RTL to each. */
2027 for (t
= decl_elts
; t
; t
= TREE_CHAIN (t
))
2029 tree decl_elt
= TREE_VALUE (t
);
2030 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (decl_elt
));
2033 /* If any of the elements are addressable, so is the entire
2035 if (TREE_USED (decl_elt
))
2036 TREE_USED (decl
) = 1;
2038 /* Propagate the union's alignment to the elements. */
2039 DECL_ALIGN (decl_elt
) = DECL_ALIGN (decl
);
2040 DECL_USER_ALIGN (decl_elt
) = DECL_USER_ALIGN (decl
);
2042 /* If the element has BLKmode and the union doesn't, the union is
2043 aligned such that the element doesn't need to have BLKmode, so
2044 change the element's mode to the appropriate one for its size. */
2045 if (mode
== BLKmode
&& DECL_MODE (decl
) != BLKmode
)
2046 DECL_MODE (decl_elt
) = mode
2047 = mode_for_size_tree (DECL_SIZE (decl_elt
), MODE_INT
, 1);
2049 if (mode
== GET_MODE (x
))
2052 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
2053 instead create a new MEM rtx with the proper mode. */
2054 decl_rtl
= adjust_address_nv (x
, mode
, 0);
2057 gcc_assert (REG_P (x
));
2058 decl_rtl
= gen_lowpart_SUBREG (mode
, x
);
2060 SET_DECL_RTL (decl_elt
, decl_rtl
);
2064 /* Do the insertion of a case label into case_list. The labels are
2065 fed to us in descending order from the sorted vector of case labels used
2066 in the tree part of the middle end. So the list we construct is
2067 sorted in ascending order. The bounds on the case range, LOW and HIGH,
2068 are converted to case's index type TYPE. */
2070 static struct case_node
*
2071 add_case_node (struct case_node
*head
, tree type
, tree low
, tree high
,
2074 tree min_value
, max_value
;
2075 struct case_node
*r
;
2077 gcc_assert (TREE_CODE (low
) == INTEGER_CST
);
2078 gcc_assert (!high
|| TREE_CODE (high
) == INTEGER_CST
);
2080 min_value
= TYPE_MIN_VALUE (type
);
2081 max_value
= TYPE_MAX_VALUE (type
);
2083 /* If there's no HIGH value, then this is not a case range; it's
2084 just a simple case label. But that's just a degenerate case
2086 If the bounds are equal, turn this into the one-value case. */
2087 if (!high
|| tree_int_cst_equal (low
, high
))
2089 /* If the simple case value is unreachable, ignore it. */
2090 if ((TREE_CODE (min_value
) == INTEGER_CST
2091 && tree_int_cst_compare (low
, min_value
) < 0)
2092 || (TREE_CODE (max_value
) == INTEGER_CST
2093 && tree_int_cst_compare (low
, max_value
) > 0))
2095 low
= fold_convert (type
, low
);
2100 /* If the entire case range is unreachable, ignore it. */
2101 if ((TREE_CODE (min_value
) == INTEGER_CST
2102 && tree_int_cst_compare (high
, min_value
) < 0)
2103 || (TREE_CODE (max_value
) == INTEGER_CST
2104 && tree_int_cst_compare (low
, max_value
) > 0))
2107 /* If the lower bound is less than the index type's minimum
2108 value, truncate the range bounds. */
2109 if (TREE_CODE (min_value
) == INTEGER_CST
2110 && tree_int_cst_compare (low
, min_value
) < 0)
2112 low
= fold_convert (type
, low
);
2114 /* If the upper bound is greater than the index type's maximum
2115 value, truncate the range bounds. */
2116 if (TREE_CODE (max_value
) == INTEGER_CST
2117 && tree_int_cst_compare (high
, max_value
) > 0)
2119 high
= fold_convert (type
, high
);
2123 /* Add this label to the chain. Make sure to drop overflow flags. */
2124 r
= ggc_alloc (sizeof (struct case_node
));
2125 r
->low
= build_int_cst_wide (TREE_TYPE (low
), TREE_INT_CST_LOW (low
),
2126 TREE_INT_CST_HIGH (low
));
2127 r
->high
= build_int_cst_wide (TREE_TYPE (high
), TREE_INT_CST_LOW (high
),
2128 TREE_INT_CST_HIGH (high
));
2129 r
->code_label
= label
;
2130 r
->parent
= r
->left
= NULL
;
2135 /* Maximum number of case bit tests. */
2136 #define MAX_CASE_BIT_TESTS 3
2138 /* By default, enable case bit tests on targets with ashlsi3. */
2139 #ifndef CASE_USE_BIT_TESTS
2140 #define CASE_USE_BIT_TESTS (ashl_optab->handlers[word_mode].insn_code \
2141 != CODE_FOR_nothing)
2145 /* A case_bit_test represents a set of case nodes that may be
2146 selected from using a bit-wise comparison. HI and LO hold
2147 the integer to be tested against, LABEL contains the label
2148 to jump to upon success and BITS counts the number of case
2149 nodes handled by this test, typically the number of bits
2152 struct case_bit_test
2160 /* Determine whether "1 << x" is relatively cheap in word_mode. */
2163 bool lshift_cheap_p (void)
2165 static bool init
= false;
2166 static bool cheap
= true;
2170 rtx reg
= gen_rtx_REG (word_mode
, 10000);
2171 int cost
= rtx_cost (gen_rtx_ASHIFT (word_mode
, const1_rtx
, reg
), SET
);
2172 cheap
= cost
< COSTS_N_INSNS (3);
2179 /* Comparison function for qsort to order bit tests by decreasing
2180 number of case nodes, i.e. the node with the most cases gets
2184 case_bit_test_cmp (const void *p1
, const void *p2
)
2186 const struct case_bit_test
*d1
= p1
;
2187 const struct case_bit_test
*d2
= p2
;
2189 if (d2
->bits
!= d1
->bits
)
2190 return d2
->bits
- d1
->bits
;
2192 /* Stabilize the sort. */
2193 return CODE_LABEL_NUMBER (d2
->label
) - CODE_LABEL_NUMBER (d1
->label
);
2196 /* Expand a switch statement by a short sequence of bit-wise
2197 comparisons. "switch(x)" is effectively converted into
2198 "if ((1 << (x-MINVAL)) & CST)" where CST and MINVAL are
2201 INDEX_EXPR is the value being switched on, which is of
2202 type INDEX_TYPE. MINVAL is the lowest case value of in
2203 the case nodes, of INDEX_TYPE type, and RANGE is highest
2204 value minus MINVAL, also of type INDEX_TYPE. NODES is
2205 the set of case nodes, and DEFAULT_LABEL is the label to
2206 branch to should none of the cases match.
2208 There *MUST* be MAX_CASE_BIT_TESTS or less unique case
2212 emit_case_bit_tests (tree index_type
, tree index_expr
, tree minval
,
2213 tree range
, case_node_ptr nodes
, rtx default_label
)
2215 struct case_bit_test test
[MAX_CASE_BIT_TESTS
];
2216 enum machine_mode mode
;
2217 rtx expr
, index
, label
;
2218 unsigned int i
,j
,lo
,hi
;
2219 struct case_node
*n
;
2223 for (n
= nodes
; n
; n
= n
->right
)
2225 label
= label_rtx (n
->code_label
);
2226 for (i
= 0; i
< count
; i
++)
2227 if (label
== test
[i
].label
)
2232 gcc_assert (count
< MAX_CASE_BIT_TESTS
);
2235 test
[i
].label
= label
;
2242 lo
= tree_low_cst (fold_build2 (MINUS_EXPR
, index_type
,
2243 n
->low
, minval
), 1);
2244 hi
= tree_low_cst (fold_build2 (MINUS_EXPR
, index_type
,
2245 n
->high
, minval
), 1);
2246 for (j
= lo
; j
<= hi
; j
++)
2247 if (j
>= HOST_BITS_PER_WIDE_INT
)
2248 test
[i
].hi
|= (HOST_WIDE_INT
) 1 << (j
- HOST_BITS_PER_INT
);
2250 test
[i
].lo
|= (HOST_WIDE_INT
) 1 << j
;
2253 qsort (test
, count
, sizeof(*test
), case_bit_test_cmp
);
2255 index_expr
= fold_build2 (MINUS_EXPR
, index_type
,
2256 fold_convert (index_type
, index_expr
),
2257 fold_convert (index_type
, minval
));
2258 index
= expand_normal (index_expr
);
2259 do_pending_stack_adjust ();
2261 mode
= TYPE_MODE (index_type
);
2262 expr
= expand_normal (range
);
2263 emit_cmp_and_jump_insns (index
, expr
, GTU
, NULL_RTX
, mode
, 1,
2266 index
= convert_to_mode (word_mode
, index
, 0);
2267 index
= expand_binop (word_mode
, ashl_optab
, const1_rtx
,
2268 index
, NULL_RTX
, 1, OPTAB_WIDEN
);
2270 for (i
= 0; i
< count
; i
++)
2272 expr
= immed_double_const (test
[i
].lo
, test
[i
].hi
, word_mode
);
2273 expr
= expand_binop (word_mode
, and_optab
, index
, expr
,
2274 NULL_RTX
, 1, OPTAB_WIDEN
);
2275 emit_cmp_and_jump_insns (expr
, const0_rtx
, NE
, NULL_RTX
,
2276 word_mode
, 1, test
[i
].label
);
2279 emit_jump (default_label
);
2283 #define HAVE_casesi 0
2286 #ifndef HAVE_tablejump
2287 #define HAVE_tablejump 0
2290 /* Terminate a case (Pascal) or switch (C) statement
2291 in which ORIG_INDEX is the expression to be tested.
2292 If ORIG_TYPE is not NULL, it is the original ORIG_INDEX
2293 type as given in the source before any compiler conversions.
2294 Generate the code to test it and jump to the right place. */
2297 expand_case (tree exp
)
2299 tree minval
= NULL_TREE
, maxval
= NULL_TREE
, range
= NULL_TREE
;
2300 rtx default_label
= 0;
2301 struct case_node
*n
;
2302 unsigned int count
, uniq
;
2308 rtx before_case
, end
, lab
;
2310 tree vec
= SWITCH_LABELS (exp
);
2311 tree orig_type
= TREE_TYPE (exp
);
2312 tree index_expr
= SWITCH_COND (exp
);
2313 tree index_type
= TREE_TYPE (index_expr
);
2314 int unsignedp
= TYPE_UNSIGNED (index_type
);
2316 /* The insn after which the case dispatch should finally
2317 be emitted. Zero for a dummy. */
2320 /* A list of case labels; it is first built as a list and it may then
2321 be rearranged into a nearly balanced binary tree. */
2322 struct case_node
*case_list
= 0;
2324 /* Label to jump to if no case matches. */
2325 tree default_label_decl
;
2327 /* The switch body is lowered in gimplify.c, we should never have
2328 switches with a non-NULL SWITCH_BODY here. */
2329 gcc_assert (!SWITCH_BODY (exp
));
2330 gcc_assert (SWITCH_LABELS (exp
));
2332 do_pending_stack_adjust ();
2334 /* An ERROR_MARK occurs for various reasons including invalid data type. */
2335 if (index_type
!= error_mark_node
)
2338 bitmap label_bitmap
;
2340 /* cleanup_tree_cfg removes all SWITCH_EXPR with their index
2341 expressions being INTEGER_CST. */
2342 gcc_assert (TREE_CODE (index_expr
) != INTEGER_CST
);
2344 /* The default case is at the end of TREE_VEC. */
2345 elt
= TREE_VEC_ELT (vec
, TREE_VEC_LENGTH (vec
) - 1);
2346 gcc_assert (!CASE_HIGH (elt
));
2347 gcc_assert (!CASE_LOW (elt
));
2348 default_label_decl
= CASE_LABEL (elt
);
2350 for (i
= TREE_VEC_LENGTH (vec
) - 1; --i
>= 0; )
2352 elt
= TREE_VEC_ELT (vec
, i
);
2353 gcc_assert (CASE_LOW (elt
));
2354 case_list
= add_case_node (case_list
, index_type
,
2355 CASE_LOW (elt
), CASE_HIGH (elt
),
2360 /* Make sure start points to something that won't need any
2361 transformation before the end of this function. */
2362 start
= get_last_insn ();
2363 if (! NOTE_P (start
))
2365 emit_note (NOTE_INSN_DELETED
);
2366 start
= get_last_insn ();
2369 default_label
= label_rtx (default_label_decl
);
2371 before_case
= get_last_insn ();
2373 /* Get upper and lower bounds of case values. */
2377 label_bitmap
= BITMAP_ALLOC (NULL
);
2378 for (n
= case_list
; n
; n
= n
->right
)
2380 /* Count the elements and track the largest and smallest
2381 of them (treating them as signed even if they are not). */
2389 if (INT_CST_LT (n
->low
, minval
))
2391 if (INT_CST_LT (maxval
, n
->high
))
2394 /* A range counts double, since it requires two compares. */
2395 if (! tree_int_cst_equal (n
->low
, n
->high
))
2398 /* If we have not seen this label yet, then increase the
2399 number of unique case node targets seen. */
2400 lab
= label_rtx (n
->code_label
);
2401 if (!bitmap_bit_p (label_bitmap
, CODE_LABEL_NUMBER (lab
)))
2403 bitmap_set_bit (label_bitmap
, CODE_LABEL_NUMBER (lab
));
2408 BITMAP_FREE (label_bitmap
);
2410 /* cleanup_tree_cfg removes all SWITCH_EXPR with a single
2411 destination, such as one with a default case only. However,
2412 it doesn't remove cases that are out of range for the switch
2413 type, so we may still get a zero here. */
2416 emit_jump (default_label
);
2420 /* Compute span of values. */
2421 range
= fold_build2 (MINUS_EXPR
, index_type
, maxval
, minval
);
2423 /* Try implementing this switch statement by a short sequence of
2424 bit-wise comparisons. However, we let the binary-tree case
2425 below handle constant index expressions. */
2426 if (CASE_USE_BIT_TESTS
2427 && ! TREE_CONSTANT (index_expr
)
2428 && compare_tree_int (range
, GET_MODE_BITSIZE (word_mode
)) < 0
2429 && compare_tree_int (range
, 0) > 0
2430 && lshift_cheap_p ()
2431 && ((uniq
== 1 && count
>= 3)
2432 || (uniq
== 2 && count
>= 5)
2433 || (uniq
== 3 && count
>= 6)))
2435 /* Optimize the case where all the case values fit in a
2436 word without having to subtract MINVAL. In this case,
2437 we can optimize away the subtraction. */
2438 if (compare_tree_int (minval
, 0) > 0
2439 && compare_tree_int (maxval
, GET_MODE_BITSIZE (word_mode
)) < 0)
2441 minval
= build_int_cst (index_type
, 0);
2444 emit_case_bit_tests (index_type
, index_expr
, minval
, range
,
2445 case_list
, default_label
);
2448 /* If range of values is much bigger than number of values,
2449 make a sequence of conditional branches instead of a dispatch.
2450 If the switch-index is a constant, do it this way
2451 because we can optimize it. */
2453 else if (count
< case_values_threshold ()
2454 || compare_tree_int (range
,
2455 (optimize_size
? 3 : 10) * count
) > 0
2456 /* RANGE may be signed, and really large ranges will show up
2457 as negative numbers. */
2458 || compare_tree_int (range
, 0) < 0
2459 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
2462 || !flag_jump_tables
2463 || TREE_CONSTANT (index_expr
)
2464 /* If neither casesi or tablejump is available, we can
2465 only go this way. */
2466 || (!HAVE_casesi
&& !HAVE_tablejump
))
2468 index
= expand_normal (index_expr
);
2470 /* If the index is a short or char that we do not have
2471 an insn to handle comparisons directly, convert it to
2472 a full integer now, rather than letting each comparison
2473 generate the conversion. */
2475 if (GET_MODE_CLASS (GET_MODE (index
)) == MODE_INT
2476 && ! have_insn_for (COMPARE
, GET_MODE (index
)))
2478 enum machine_mode wider_mode
;
2479 for (wider_mode
= GET_MODE (index
); wider_mode
!= VOIDmode
;
2480 wider_mode
= GET_MODE_WIDER_MODE (wider_mode
))
2481 if (have_insn_for (COMPARE
, wider_mode
))
2483 index
= convert_to_mode (wider_mode
, index
, unsignedp
);
2488 do_pending_stack_adjust ();
2491 index
= copy_to_reg (index
);
2493 /* We generate a binary decision tree to select the
2494 appropriate target code. This is done as follows:
2496 The list of cases is rearranged into a binary tree,
2497 nearly optimal assuming equal probability for each case.
2499 The tree is transformed into RTL, eliminating
2500 redundant test conditions at the same time.
2502 If program flow could reach the end of the
2503 decision tree an unconditional jump to the
2504 default code is emitted. */
2507 = (TREE_CODE (orig_type
) != ENUMERAL_TYPE
2508 && estimate_case_costs (case_list
));
2509 balance_case_nodes (&case_list
, NULL
);
2510 emit_case_nodes (index
, case_list
, default_label
, index_type
);
2511 emit_jump (default_label
);
2515 table_label
= gen_label_rtx ();
2516 if (! try_casesi (index_type
, index_expr
, minval
, range
,
2517 table_label
, default_label
))
2521 /* Index jumptables from zero for suitable values of
2522 minval to avoid a subtraction. */
2524 && compare_tree_int (minval
, 0) > 0
2525 && compare_tree_int (minval
, 3) < 0)
2527 minval
= build_int_cst (index_type
, 0);
2531 ok
= try_tablejump (index_type
, index_expr
, minval
, range
,
2532 table_label
, default_label
);
2536 /* Get table of labels to jump to, in order of case index. */
2538 ncases
= tree_low_cst (range
, 0) + 1;
2539 labelvec
= alloca (ncases
* sizeof (rtx
));
2540 memset (labelvec
, 0, ncases
* sizeof (rtx
));
2542 for (n
= case_list
; n
; n
= n
->right
)
2544 /* Compute the low and high bounds relative to the minimum
2545 value since that should fit in a HOST_WIDE_INT while the
2546 actual values may not. */
2548 = tree_low_cst (fold_build2 (MINUS_EXPR
, index_type
,
2549 n
->low
, minval
), 1);
2550 HOST_WIDE_INT i_high
2551 = tree_low_cst (fold_build2 (MINUS_EXPR
, index_type
,
2552 n
->high
, minval
), 1);
2555 for (i
= i_low
; i
<= i_high
; i
++)
2557 = gen_rtx_LABEL_REF (Pmode
, label_rtx (n
->code_label
));
2560 /* Fill in the gaps with the default. */
2561 for (i
= 0; i
< ncases
; i
++)
2562 if (labelvec
[i
] == 0)
2563 labelvec
[i
] = gen_rtx_LABEL_REF (Pmode
, default_label
);
2565 /* Output the table. */
2566 emit_label (table_label
);
2568 if (CASE_VECTOR_PC_RELATIVE
|| flag_pic
)
2569 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE
,
2570 gen_rtx_LABEL_REF (Pmode
, table_label
),
2571 gen_rtvec_v (ncases
, labelvec
),
2572 const0_rtx
, const0_rtx
));
2574 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE
,
2575 gen_rtvec_v (ncases
, labelvec
)));
2577 /* Record no drop-through after the table. */
2581 before_case
= NEXT_INSN (before_case
);
2582 end
= get_last_insn ();
2583 fail
= squeeze_notes (&before_case
, &end
);
2585 reorder_insns (before_case
, end
, start
);
2591 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
2594 do_jump_if_equal (rtx op1
, rtx op2
, rtx label
, int unsignedp
)
2596 if (GET_CODE (op1
) == CONST_INT
&& GET_CODE (op2
) == CONST_INT
)
2602 emit_cmp_and_jump_insns (op1
, op2
, EQ
, NULL_RTX
,
2603 (GET_MODE (op1
) == VOIDmode
2604 ? GET_MODE (op2
) : GET_MODE (op1
)),
2608 /* Not all case values are encountered equally. This function
2609 uses a heuristic to weight case labels, in cases where that
2610 looks like a reasonable thing to do.
2612 Right now, all we try to guess is text, and we establish the
2615 chars above space: 16
2624 If we find any cases in the switch that are not either -1 or in the range
2625 of valid ASCII characters, or are control characters other than those
2626 commonly used with "\", don't treat this switch scanning text.
2628 Return 1 if these nodes are suitable for cost estimation, otherwise
2632 estimate_case_costs (case_node_ptr node
)
2634 tree min_ascii
= integer_minus_one_node
;
2635 tree max_ascii
= build_int_cst (TREE_TYPE (node
->high
), 127);
2639 /* If we haven't already made the cost table, make it now. Note that the
2640 lower bound of the table is -1, not zero. */
2642 if (! cost_table_initialized
)
2644 cost_table_initialized
= 1;
2646 for (i
= 0; i
< 128; i
++)
2649 COST_TABLE (i
) = 16;
2650 else if (ISPUNCT (i
))
2652 else if (ISCNTRL (i
))
2653 COST_TABLE (i
) = -1;
2656 COST_TABLE (' ') = 8;
2657 COST_TABLE ('\t') = 4;
2658 COST_TABLE ('\0') = 4;
2659 COST_TABLE ('\n') = 2;
2660 COST_TABLE ('\f') = 1;
2661 COST_TABLE ('\v') = 1;
2662 COST_TABLE ('\b') = 1;
2665 /* See if all the case expressions look like text. It is text if the
2666 constant is >= -1 and the highest constant is <= 127. Do all comparisons
2667 as signed arithmetic since we don't want to ever access cost_table with a
2668 value less than -1. Also check that none of the constants in a range
2669 are strange control characters. */
2671 for (n
= node
; n
; n
= n
->right
)
2673 if ((INT_CST_LT (n
->low
, min_ascii
)) || INT_CST_LT (max_ascii
, n
->high
))
2676 for (i
= (HOST_WIDE_INT
) TREE_INT_CST_LOW (n
->low
);
2677 i
<= (HOST_WIDE_INT
) TREE_INT_CST_LOW (n
->high
); i
++)
2678 if (COST_TABLE (i
) < 0)
2682 /* All interesting values are within the range of interesting
2683 ASCII characters. */
2687 /* Take an ordered list of case nodes
2688 and transform them into a near optimal binary tree,
2689 on the assumption that any target code selection value is as
2690 likely as any other.
2692 The transformation is performed by splitting the ordered
2693 list into two equal sections plus a pivot. The parts are
2694 then attached to the pivot as left and right branches. Each
2695 branch is then transformed recursively. */
2698 balance_case_nodes (case_node_ptr
*head
, case_node_ptr parent
)
2711 /* Count the number of entries on branch. Also count the ranges. */
2715 if (!tree_int_cst_equal (np
->low
, np
->high
))
2719 cost
+= COST_TABLE (TREE_INT_CST_LOW (np
->high
));
2723 cost
+= COST_TABLE (TREE_INT_CST_LOW (np
->low
));
2731 /* Split this list if it is long enough for that to help. */
2736 /* Find the place in the list that bisects the list's total cost,
2737 Here I gets half the total cost. */
2742 /* Skip nodes while their cost does not reach that amount. */
2743 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
2744 i
-= COST_TABLE (TREE_INT_CST_LOW ((*npp
)->high
));
2745 i
-= COST_TABLE (TREE_INT_CST_LOW ((*npp
)->low
));
2748 npp
= &(*npp
)->right
;
2753 /* Leave this branch lopsided, but optimize left-hand
2754 side and fill in `parent' fields for right-hand side. */
2756 np
->parent
= parent
;
2757 balance_case_nodes (&np
->left
, np
);
2758 for (; np
->right
; np
= np
->right
)
2759 np
->right
->parent
= np
;
2763 /* If there are just three nodes, split at the middle one. */
2765 npp
= &(*npp
)->right
;
2768 /* Find the place in the list that bisects the list's total cost,
2769 where ranges count as 2.
2770 Here I gets half the total cost. */
2771 i
= (i
+ ranges
+ 1) / 2;
2774 /* Skip nodes while their cost does not reach that amount. */
2775 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
2780 npp
= &(*npp
)->right
;
2785 np
->parent
= parent
;
2788 /* Optimize each of the two split parts. */
2789 balance_case_nodes (&np
->left
, np
);
2790 balance_case_nodes (&np
->right
, np
);
2794 /* Else leave this branch as one level,
2795 but fill in `parent' fields. */
2797 np
->parent
= parent
;
2798 for (; np
->right
; np
= np
->right
)
2799 np
->right
->parent
= np
;
2804 /* Search the parent sections of the case node tree
2805 to see if a test for the lower bound of NODE would be redundant.
2806 INDEX_TYPE is the type of the index expression.
2808 The instructions to generate the case decision tree are
2809 output in the same order as nodes are processed so it is
2810 known that if a parent node checks the range of the current
2811 node minus one that the current node is bounded at its lower
2812 span. Thus the test would be redundant. */
2815 node_has_low_bound (case_node_ptr node
, tree index_type
)
2818 case_node_ptr pnode
;
2820 /* If the lower bound of this node is the lowest value in the index type,
2821 we need not test it. */
2823 if (tree_int_cst_equal (node
->low
, TYPE_MIN_VALUE (index_type
)))
2826 /* If this node has a left branch, the value at the left must be less
2827 than that at this node, so it cannot be bounded at the bottom and
2828 we need not bother testing any further. */
2833 low_minus_one
= fold_build2 (MINUS_EXPR
, TREE_TYPE (node
->low
),
2835 build_int_cst (TREE_TYPE (node
->low
), 1));
2837 /* If the subtraction above overflowed, we can't verify anything.
2838 Otherwise, look for a parent that tests our value - 1. */
2840 if (! tree_int_cst_lt (low_minus_one
, node
->low
))
2843 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
2844 if (tree_int_cst_equal (low_minus_one
, pnode
->high
))
2850 /* Search the parent sections of the case node tree
2851 to see if a test for the upper bound of NODE would be redundant.
2852 INDEX_TYPE is the type of the index expression.
2854 The instructions to generate the case decision tree are
2855 output in the same order as nodes are processed so it is
2856 known that if a parent node checks the range of the current
2857 node plus one that the current node is bounded at its upper
2858 span. Thus the test would be redundant. */
2861 node_has_high_bound (case_node_ptr node
, tree index_type
)
2864 case_node_ptr pnode
;
2866 /* If there is no upper bound, obviously no test is needed. */
2868 if (TYPE_MAX_VALUE (index_type
) == NULL
)
2871 /* If the upper bound of this node is the highest value in the type
2872 of the index expression, we need not test against it. */
2874 if (tree_int_cst_equal (node
->high
, TYPE_MAX_VALUE (index_type
)))
2877 /* If this node has a right branch, the value at the right must be greater
2878 than that at this node, so it cannot be bounded at the top and
2879 we need not bother testing any further. */
2884 high_plus_one
= fold_build2 (PLUS_EXPR
, TREE_TYPE (node
->high
),
2886 build_int_cst (TREE_TYPE (node
->high
), 1));
2888 /* If the addition above overflowed, we can't verify anything.
2889 Otherwise, look for a parent that tests our value + 1. */
2891 if (! tree_int_cst_lt (node
->high
, high_plus_one
))
2894 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
2895 if (tree_int_cst_equal (high_plus_one
, pnode
->low
))
2901 /* Search the parent sections of the
2902 case node tree to see if both tests for the upper and lower
2903 bounds of NODE would be redundant. */
2906 node_is_bounded (case_node_ptr node
, tree index_type
)
2908 return (node_has_low_bound (node
, index_type
)
2909 && node_has_high_bound (node
, index_type
));
2912 /* Emit step-by-step code to select a case for the value of INDEX.
2913 The thus generated decision tree follows the form of the
2914 case-node binary tree NODE, whose nodes represent test conditions.
2915 INDEX_TYPE is the type of the index of the switch.
2917 Care is taken to prune redundant tests from the decision tree
2918 by detecting any boundary conditions already checked by
2919 emitted rtx. (See node_has_high_bound, node_has_low_bound
2920 and node_is_bounded, above.)
2922 Where the test conditions can be shown to be redundant we emit
2923 an unconditional jump to the target code. As a further
2924 optimization, the subordinates of a tree node are examined to
2925 check for bounded nodes. In this case conditional and/or
2926 unconditional jumps as a result of the boundary check for the
2927 current node are arranged to target the subordinates associated
2928 code for out of bound conditions on the current node.
2930 We can assume that when control reaches the code generated here,
2931 the index value has already been compared with the parents
2932 of this node, and determined to be on the same side of each parent
2933 as this node is. Thus, if this node tests for the value 51,
2934 and a parent tested for 52, we don't need to consider
2935 the possibility of a value greater than 51. If another parent
2936 tests for the value 50, then this node need not test anything. */
2939 emit_case_nodes (rtx index
, case_node_ptr node
, rtx default_label
,
2942 /* If INDEX has an unsigned type, we must make unsigned branches. */
2943 int unsignedp
= TYPE_UNSIGNED (index_type
);
2944 enum machine_mode mode
= GET_MODE (index
);
2945 enum machine_mode imode
= TYPE_MODE (index_type
);
2947 /* See if our parents have already tested everything for us.
2948 If they have, emit an unconditional jump for this node. */
2949 if (node_is_bounded (node
, index_type
))
2950 emit_jump (label_rtx (node
->code_label
));
2952 else if (tree_int_cst_equal (node
->low
, node
->high
))
2954 /* Node is single valued. First see if the index expression matches
2955 this node and then check our children, if any. */
2957 do_jump_if_equal (index
,
2958 convert_modes (mode
, imode
,
2959 expand_normal (node
->low
),
2961 label_rtx (node
->code_label
), unsignedp
);
2963 if (node
->right
!= 0 && node
->left
!= 0)
2965 /* This node has children on both sides.
2966 Dispatch to one side or the other
2967 by comparing the index value with this node's value.
2968 If one subtree is bounded, check that one first,
2969 so we can avoid real branches in the tree. */
2971 if (node_is_bounded (node
->right
, index_type
))
2973 emit_cmp_and_jump_insns (index
,
2976 expand_normal (node
->high
),
2978 GT
, NULL_RTX
, mode
, unsignedp
,
2979 label_rtx (node
->right
->code_label
));
2980 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
2983 else if (node_is_bounded (node
->left
, index_type
))
2985 emit_cmp_and_jump_insns (index
,
2988 expand_normal (node
->high
),
2990 LT
, NULL_RTX
, mode
, unsignedp
,
2991 label_rtx (node
->left
->code_label
));
2992 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
2995 /* If both children are single-valued cases with no
2996 children, finish up all the work. This way, we can save
2997 one ordered comparison. */
2998 else if (tree_int_cst_equal (node
->right
->low
, node
->right
->high
)
2999 && node
->right
->left
== 0
3000 && node
->right
->right
== 0
3001 && tree_int_cst_equal (node
->left
->low
, node
->left
->high
)
3002 && node
->left
->left
== 0
3003 && node
->left
->right
== 0)
3005 /* Neither node is bounded. First distinguish the two sides;
3006 then emit the code for one side at a time. */
3008 /* See if the value matches what the right hand side
3010 do_jump_if_equal (index
,
3011 convert_modes (mode
, imode
,
3012 expand_normal (node
->right
->low
),
3014 label_rtx (node
->right
->code_label
),
3017 /* See if the value matches what the left hand side
3019 do_jump_if_equal (index
,
3020 convert_modes (mode
, imode
,
3021 expand_normal (node
->left
->low
),
3023 label_rtx (node
->left
->code_label
),
3029 /* Neither node is bounded. First distinguish the two sides;
3030 then emit the code for one side at a time. */
3032 tree test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
3034 /* See if the value is on the right. */
3035 emit_cmp_and_jump_insns (index
,
3038 expand_normal (node
->high
),
3040 GT
, NULL_RTX
, mode
, unsignedp
,
3041 label_rtx (test_label
));
3043 /* Value must be on the left.
3044 Handle the left-hand subtree. */
3045 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
3046 /* If left-hand subtree does nothing,
3048 emit_jump (default_label
);
3050 /* Code branches here for the right-hand subtree. */
3051 expand_label (test_label
);
3052 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
3056 else if (node
->right
!= 0 && node
->left
== 0)
3058 /* Here we have a right child but no left so we issue a conditional
3059 branch to default and process the right child.
3061 Omit the conditional branch to default if the right child
3062 does not have any children and is single valued; it would
3063 cost too much space to save so little time. */
3065 if (node
->right
->right
|| node
->right
->left
3066 || !tree_int_cst_equal (node
->right
->low
, node
->right
->high
))
3068 if (!node_has_low_bound (node
, index_type
))
3070 emit_cmp_and_jump_insns (index
,
3073 expand_normal (node
->high
),
3075 LT
, NULL_RTX
, mode
, unsignedp
,
3079 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
3082 /* We cannot process node->right normally
3083 since we haven't ruled out the numbers less than
3084 this node's value. So handle node->right explicitly. */
3085 do_jump_if_equal (index
,
3088 expand_normal (node
->right
->low
),
3090 label_rtx (node
->right
->code_label
), unsignedp
);
3093 else if (node
->right
== 0 && node
->left
!= 0)
3095 /* Just one subtree, on the left. */
3096 if (node
->left
->left
|| node
->left
->right
3097 || !tree_int_cst_equal (node
->left
->low
, node
->left
->high
))
3099 if (!node_has_high_bound (node
, index_type
))
3101 emit_cmp_and_jump_insns (index
,
3104 expand_normal (node
->high
),
3106 GT
, NULL_RTX
, mode
, unsignedp
,
3110 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
3113 /* We cannot process node->left normally
3114 since we haven't ruled out the numbers less than
3115 this node's value. So handle node->left explicitly. */
3116 do_jump_if_equal (index
,
3119 expand_normal (node
->left
->low
),
3121 label_rtx (node
->left
->code_label
), unsignedp
);
3126 /* Node is a range. These cases are very similar to those for a single
3127 value, except that we do not start by testing whether this node
3128 is the one to branch to. */
3130 if (node
->right
!= 0 && node
->left
!= 0)
3132 /* Node has subtrees on both sides.
3133 If the right-hand subtree is bounded,
3134 test for it first, since we can go straight there.
3135 Otherwise, we need to make a branch in the control structure,
3136 then handle the two subtrees. */
3137 tree test_label
= 0;
3139 if (node_is_bounded (node
->right
, index_type
))
3140 /* Right hand node is fully bounded so we can eliminate any
3141 testing and branch directly to the target code. */
3142 emit_cmp_and_jump_insns (index
,
3145 expand_normal (node
->high
),
3147 GT
, NULL_RTX
, mode
, unsignedp
,
3148 label_rtx (node
->right
->code_label
));
3151 /* Right hand node requires testing.
3152 Branch to a label where we will handle it later. */
3154 test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
3155 emit_cmp_and_jump_insns (index
,
3158 expand_normal (node
->high
),
3160 GT
, NULL_RTX
, mode
, unsignedp
,
3161 label_rtx (test_label
));
3164 /* Value belongs to this node or to the left-hand subtree. */
3166 emit_cmp_and_jump_insns (index
,
3169 expand_normal (node
->low
),
3171 GE
, NULL_RTX
, mode
, unsignedp
,
3172 label_rtx (node
->code_label
));
3174 /* Handle the left-hand subtree. */
3175 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
3177 /* If right node had to be handled later, do that now. */
3181 /* If the left-hand subtree fell through,
3182 don't let it fall into the right-hand subtree. */
3183 emit_jump (default_label
);
3185 expand_label (test_label
);
3186 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
3190 else if (node
->right
!= 0 && node
->left
== 0)
3192 /* Deal with values to the left of this node,
3193 if they are possible. */
3194 if (!node_has_low_bound (node
, index_type
))
3196 emit_cmp_and_jump_insns (index
,
3199 expand_normal (node
->low
),
3201 LT
, NULL_RTX
, mode
, unsignedp
,
3205 /* Value belongs to this node or to the right-hand subtree. */
3207 emit_cmp_and_jump_insns (index
,
3210 expand_normal (node
->high
),
3212 LE
, NULL_RTX
, mode
, unsignedp
,
3213 label_rtx (node
->code_label
));
3215 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
3218 else if (node
->right
== 0 && node
->left
!= 0)
3220 /* Deal with values to the right of this node,
3221 if they are possible. */
3222 if (!node_has_high_bound (node
, index_type
))
3224 emit_cmp_and_jump_insns (index
,
3227 expand_normal (node
->high
),
3229 GT
, NULL_RTX
, mode
, unsignedp
,
3233 /* Value belongs to this node or to the left-hand subtree. */
3235 emit_cmp_and_jump_insns (index
,
3238 expand_normal (node
->low
),
3240 GE
, NULL_RTX
, mode
, unsignedp
,
3241 label_rtx (node
->code_label
));
3243 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
3248 /* Node has no children so we check low and high bounds to remove
3249 redundant tests. Only one of the bounds can exist,
3250 since otherwise this node is bounded--a case tested already. */
3251 int high_bound
= node_has_high_bound (node
, index_type
);
3252 int low_bound
= node_has_low_bound (node
, index_type
);
3254 if (!high_bound
&& low_bound
)
3256 emit_cmp_and_jump_insns (index
,
3259 expand_normal (node
->high
),
3261 GT
, NULL_RTX
, mode
, unsignedp
,
3265 else if (!low_bound
&& high_bound
)
3267 emit_cmp_and_jump_insns (index
,
3270 expand_normal (node
->low
),
3272 LT
, NULL_RTX
, mode
, unsignedp
,
3275 else if (!low_bound
&& !high_bound
)
3277 /* Widen LOW and HIGH to the same width as INDEX. */
3278 tree type
= lang_hooks
.types
.type_for_mode (mode
, unsignedp
);
3279 tree low
= build1 (CONVERT_EXPR
, type
, node
->low
);
3280 tree high
= build1 (CONVERT_EXPR
, type
, node
->high
);
3281 rtx low_rtx
, new_index
, new_bound
;
3283 /* Instead of doing two branches, emit one unsigned branch for
3284 (index-low) > (high-low). */
3285 low_rtx
= expand_expr (low
, NULL_RTX
, mode
, EXPAND_NORMAL
);
3286 new_index
= expand_simple_binop (mode
, MINUS
, index
, low_rtx
,
3287 NULL_RTX
, unsignedp
,
3289 new_bound
= expand_expr (fold_build2 (MINUS_EXPR
, type
,
3291 NULL_RTX
, mode
, EXPAND_NORMAL
);
3293 emit_cmp_and_jump_insns (new_index
, new_bound
, GT
, NULL_RTX
,
3294 mode
, 1, default_label
);
3297 emit_jump (label_rtx (node
->code_label
));