1 /* Expands front end tree to back end RTL for GCC
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 2, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to the Free
20 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
23 /* This file handles the generation of rtl code from tree structure
24 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
25 The functions whose names start with `expand_' are called by the
26 expander to generate RTL instructions for various kinds of constructs. */
30 #include "coretypes.h"
34 #include "hard-reg-set.h"
40 #include "insn-config.h"
48 #include "langhooks.h"
54 /* Functions and data structures for expanding case statements. */
56 /* Case label structure, used to hold info on labels within case
57 statements. We handle "range" labels; for a single-value label
58 as in C, the high and low limits are the same.
60 We start with a vector of case nodes sorted in ascending order, and
61 the default label as the last element in the vector. Before expanding
62 to RTL, we transform this vector into a list linked via the RIGHT
63 fields in the case_node struct. Nodes with higher case values are
66 Switch statements can be output in three forms. A branch table is
67 used if there are more than a few labels and the labels are dense
68 within the range between the smallest and largest case value. If a
69 branch table is used, no further manipulations are done with the case
72 The alternative to the use of a branch table is to generate a series
73 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
74 and PARENT fields to hold a binary tree. Initially the tree is
75 totally unbalanced, with everything on the right. We balance the tree
76 with nodes on the left having lower case values than the parent
77 and nodes on the right having higher values. We then output the tree
80 For very small, suitable switch statements, we can generate a series
81 of simple bit test and branches instead. */
83 struct case_node
GTY(())
85 struct case_node
*left
; /* Left son in binary tree */
86 struct case_node
*right
; /* Right son in binary tree; also node chain */
87 struct case_node
*parent
; /* Parent of node in binary tree */
88 tree low
; /* Lowest index value for this label */
89 tree high
; /* Highest index value for this label */
90 tree code_label
; /* Label to jump to when node matches */
93 typedef struct case_node case_node
;
94 typedef struct case_node
*case_node_ptr
;
96 /* These are used by estimate_case_costs and balance_case_nodes. */
98 /* This must be a signed type, and non-ANSI compilers lack signed char. */
99 static short cost_table_
[129];
100 static int use_cost_table
;
101 static int cost_table_initialized
;
103 /* Special care is needed because we allow -1, but TREE_INT_CST_LOW
105 #define COST_TABLE(I) cost_table_[(unsigned HOST_WIDE_INT) ((I) + 1)]
107 static int n_occurrences (int, const char *);
108 static bool tree_conflicts_with_clobbers_p (tree
, HARD_REG_SET
*);
109 static void expand_nl_goto_receiver (void);
110 static bool check_operand_nalternatives (tree
, tree
);
111 static bool check_unique_operand_names (tree
, tree
);
112 static char *resolve_operand_name_1 (char *, tree
, tree
);
113 static void expand_null_return_1 (void);
114 static void expand_value_return (rtx
);
115 static int estimate_case_costs (case_node_ptr
);
116 static bool lshift_cheap_p (void);
117 static int case_bit_test_cmp (const void *, const void *);
118 static void emit_case_bit_tests (tree
, tree
, tree
, tree
, case_node_ptr
, rtx
);
119 static void balance_case_nodes (case_node_ptr
*, case_node_ptr
);
120 static int node_has_low_bound (case_node_ptr
, tree
);
121 static int node_has_high_bound (case_node_ptr
, tree
);
122 static int node_is_bounded (case_node_ptr
, tree
);
123 static void emit_case_nodes (rtx
, case_node_ptr
, rtx
, tree
);
124 static struct case_node
*add_case_node (struct case_node
*, tree
,
128 /* Return the rtx-label that corresponds to a LABEL_DECL,
129 creating it if necessary. */
132 label_rtx (tree label
)
134 gcc_assert (TREE_CODE (label
) == LABEL_DECL
);
136 if (!DECL_RTL_SET_P (label
))
138 rtx r
= gen_label_rtx ();
139 SET_DECL_RTL (label
, r
);
140 if (FORCED_LABEL (label
) || DECL_NONLOCAL (label
))
141 LABEL_PRESERVE_P (r
) = 1;
144 return DECL_RTL (label
);
147 /* As above, but also put it on the forced-reference list of the
148 function that contains it. */
150 force_label_rtx (tree label
)
152 rtx ref
= label_rtx (label
);
153 tree function
= decl_function_context (label
);
156 gcc_assert (function
);
158 if (function
!= current_function_decl
)
159 p
= find_function_data (function
);
163 p
->expr
->x_forced_labels
= gen_rtx_EXPR_LIST (VOIDmode
, ref
,
164 p
->expr
->x_forced_labels
);
168 /* Add an unconditional jump to LABEL as the next sequential instruction. */
171 emit_jump (rtx label
)
173 do_pending_stack_adjust ();
174 emit_jump_insn (gen_jump (label
));
178 /* Emit code to jump to the address
179 specified by the pointer expression EXP. */
182 expand_computed_goto (tree exp
)
184 rtx x
= expand_normal (exp
);
186 x
= convert_memory_address (Pmode
, x
);
188 do_pending_stack_adjust ();
189 emit_indirect_jump (x
);
192 /* Handle goto statements and the labels that they can go to. */
194 /* Specify the location in the RTL code of a label LABEL,
195 which is a LABEL_DECL tree node.
197 This is used for the kind of label that the user can jump to with a
198 goto statement, and for alternatives of a switch or case statement.
199 RTL labels generated for loops and conditionals don't go through here;
200 they are generated directly at the RTL level, by other functions below.
202 Note that this has nothing to do with defining label *names*.
203 Languages vary in how they do that and what that even means. */
206 expand_label (tree label
)
208 rtx label_r
= label_rtx (label
);
210 do_pending_stack_adjust ();
211 emit_label (label_r
);
212 if (DECL_NAME (label
))
213 LABEL_NAME (DECL_RTL (label
)) = IDENTIFIER_POINTER (DECL_NAME (label
));
215 if (DECL_NONLOCAL (label
))
217 expand_nl_goto_receiver ();
218 nonlocal_goto_handler_labels
219 = gen_rtx_EXPR_LIST (VOIDmode
, label_r
,
220 nonlocal_goto_handler_labels
);
223 if (FORCED_LABEL (label
))
224 forced_labels
= gen_rtx_EXPR_LIST (VOIDmode
, label_r
, forced_labels
);
226 if (DECL_NONLOCAL (label
) || FORCED_LABEL (label
))
227 maybe_set_first_label_num (label_r
);
230 /* Generate RTL code for a `goto' statement with target label LABEL.
231 LABEL should be a LABEL_DECL tree node that was or will later be
232 defined with `expand_label'. */
235 expand_goto (tree label
)
237 #ifdef ENABLE_CHECKING
238 /* Check for a nonlocal goto to a containing function. Should have
239 gotten translated to __builtin_nonlocal_goto. */
240 tree context
= decl_function_context (label
);
241 gcc_assert (!context
|| context
== current_function_decl
);
244 emit_jump (label_rtx (label
));
247 /* Return the number of times character C occurs in string S. */
249 n_occurrences (int c
, const char *s
)
257 /* Generate RTL for an asm statement (explicit assembler code).
258 STRING is a STRING_CST node containing the assembler code text,
259 or an ADDR_EXPR containing a STRING_CST. VOL nonzero means the
260 insn is volatile; don't optimize it. */
263 expand_asm_loc (tree string
, int vol
, location_t locus
)
267 if (TREE_CODE (string
) == ADDR_EXPR
)
268 string
= TREE_OPERAND (string
, 0);
270 body
= gen_rtx_ASM_INPUT_loc (VOIDmode
,
271 ggc_strdup (TREE_STRING_POINTER (string
)),
274 MEM_VOLATILE_P (body
) = vol
;
279 /* Parse the output constraint pointed to by *CONSTRAINT_P. It is the
280 OPERAND_NUMth output operand, indexed from zero. There are NINPUTS
281 inputs and NOUTPUTS outputs to this extended-asm. Upon return,
282 *ALLOWS_MEM will be TRUE iff the constraint allows the use of a
283 memory operand. Similarly, *ALLOWS_REG will be TRUE iff the
284 constraint allows the use of a register operand. And, *IS_INOUT
285 will be true if the operand is read-write, i.e., if it is used as
286 an input as well as an output. If *CONSTRAINT_P is not in
287 canonical form, it will be made canonical. (Note that `+' will be
288 replaced with `=' as part of this process.)
290 Returns TRUE if all went well; FALSE if an error occurred. */
293 parse_output_constraint (const char **constraint_p
, int operand_num
,
294 int ninputs
, int noutputs
, bool *allows_mem
,
295 bool *allows_reg
, bool *is_inout
)
297 const char *constraint
= *constraint_p
;
300 /* Assume the constraint doesn't allow the use of either a register
305 /* Allow the `=' or `+' to not be at the beginning of the string,
306 since it wasn't explicitly documented that way, and there is a
307 large body of code that puts it last. Swap the character to
308 the front, so as not to uglify any place else. */
309 p
= strchr (constraint
, '=');
311 p
= strchr (constraint
, '+');
313 /* If the string doesn't contain an `=', issue an error
317 error ("output operand constraint lacks %<=%>");
321 /* If the constraint begins with `+', then the operand is both read
322 from and written to. */
323 *is_inout
= (*p
== '+');
325 /* Canonicalize the output constraint so that it begins with `='. */
326 if (p
!= constraint
|| *is_inout
)
329 size_t c_len
= strlen (constraint
);
332 warning (0, "output constraint %qc for operand %d "
333 "is not at the beginning",
336 /* Make a copy of the constraint. */
337 buf
= alloca (c_len
+ 1);
338 strcpy (buf
, constraint
);
339 /* Swap the first character and the `=' or `+'. */
340 buf
[p
- constraint
] = buf
[0];
341 /* Make sure the first character is an `='. (Until we do this,
342 it might be a `+'.) */
344 /* Replace the constraint with the canonicalized string. */
345 *constraint_p
= ggc_alloc_string (buf
, c_len
);
346 constraint
= *constraint_p
;
349 /* Loop through the constraint string. */
350 for (p
= constraint
+ 1; *p
; p
+= CONSTRAINT_LEN (*p
, p
))
355 error ("operand constraint contains incorrectly positioned "
360 if (operand_num
+ 1 == ninputs
+ noutputs
)
362 error ("%<%%%> constraint used with last operand");
367 case 'V': case 'm': case 'o':
371 case '?': case '!': case '*': case '&': case '#':
372 case 'E': case 'F': case 'G': case 'H':
373 case 's': case 'i': case 'n':
374 case 'I': case 'J': case 'K': case 'L': case 'M':
375 case 'N': case 'O': case 'P': case ',':
378 case '0': case '1': case '2': case '3': case '4':
379 case '5': case '6': case '7': case '8': case '9':
381 error ("matching constraint not valid in output operand");
385 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
386 excepting those that expand_call created. So match memory
403 if (REG_CLASS_FROM_CONSTRAINT (*p
, p
) != NO_REGS
)
405 #ifdef EXTRA_CONSTRAINT_STR
406 else if (EXTRA_ADDRESS_CONSTRAINT (*p
, p
))
408 else if (EXTRA_MEMORY_CONSTRAINT (*p
, p
))
412 /* Otherwise we can't assume anything about the nature of
413 the constraint except that it isn't purely registers.
414 Treat it like "g" and hope for the best. */
425 /* Similar, but for input constraints. */
428 parse_input_constraint (const char **constraint_p
, int input_num
,
429 int ninputs
, int noutputs
, int ninout
,
430 const char * const * constraints
,
431 bool *allows_mem
, bool *allows_reg
)
433 const char *constraint
= *constraint_p
;
434 const char *orig_constraint
= constraint
;
435 size_t c_len
= strlen (constraint
);
437 bool saw_match
= false;
439 /* Assume the constraint doesn't allow the use of either
440 a register or memory. */
444 /* Make sure constraint has neither `=', `+', nor '&'. */
446 for (j
= 0; j
< c_len
; j
+= CONSTRAINT_LEN (constraint
[j
], constraint
+j
))
447 switch (constraint
[j
])
449 case '+': case '=': case '&':
450 if (constraint
== orig_constraint
)
452 error ("input operand constraint contains %qc", constraint
[j
]);
458 if (constraint
== orig_constraint
459 && input_num
+ 1 == ninputs
- ninout
)
461 error ("%<%%%> constraint used with last operand");
466 case 'V': case 'm': case 'o':
471 case '?': case '!': case '*': case '#':
472 case 'E': case 'F': case 'G': case 'H':
473 case 's': case 'i': case 'n':
474 case 'I': case 'J': case 'K': case 'L': case 'M':
475 case 'N': case 'O': case 'P': case ',':
478 /* Whether or not a numeric constraint allows a register is
479 decided by the matching constraint, and so there is no need
480 to do anything special with them. We must handle them in
481 the default case, so that we don't unnecessarily force
482 operands to memory. */
483 case '0': case '1': case '2': case '3': case '4':
484 case '5': case '6': case '7': case '8': case '9':
491 match
= strtoul (constraint
+ j
, &end
, 10);
492 if (match
>= (unsigned long) noutputs
)
494 error ("matching constraint references invalid operand number");
498 /* Try and find the real constraint for this dup. Only do this
499 if the matching constraint is the only alternative. */
501 && (j
== 0 || (j
== 1 && constraint
[0] == '%')))
503 constraint
= constraints
[match
];
504 *constraint_p
= constraint
;
505 c_len
= strlen (constraint
);
507 /* ??? At the end of the loop, we will skip the first part of
508 the matched constraint. This assumes not only that the
509 other constraint is an output constraint, but also that
510 the '=' or '+' come first. */
514 j
= end
- constraint
;
515 /* Anticipate increment at end of loop. */
530 if (! ISALPHA (constraint
[j
]))
532 error ("invalid punctuation %qc in constraint", constraint
[j
]);
535 if (REG_CLASS_FROM_CONSTRAINT (constraint
[j
], constraint
+ j
)
538 #ifdef EXTRA_CONSTRAINT_STR
539 else if (EXTRA_ADDRESS_CONSTRAINT (constraint
[j
], constraint
+ j
))
541 else if (EXTRA_MEMORY_CONSTRAINT (constraint
[j
], constraint
+ j
))
545 /* Otherwise we can't assume anything about the nature of
546 the constraint except that it isn't purely registers.
547 Treat it like "g" and hope for the best. */
555 if (saw_match
&& !*allows_reg
)
556 warning (0, "matching constraint does not allow a register");
561 /* Return DECL iff there's an overlap between *REGS and DECL, where DECL
562 can be an asm-declared register. Called via walk_tree. */
565 decl_overlaps_hard_reg_set_p (tree
*declp
, int *walk_subtrees ATTRIBUTE_UNUSED
,
569 const HARD_REG_SET
*regs
= data
;
571 if (TREE_CODE (decl
) == VAR_DECL
)
573 if (DECL_HARD_REGISTER (decl
)
574 && REG_P (DECL_RTL (decl
))
575 && REGNO (DECL_RTL (decl
)) < FIRST_PSEUDO_REGISTER
)
577 rtx reg
= DECL_RTL (decl
);
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
) || TREE_CODE (decl
) == PARM_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
))
699 if (TREE_VALUE (tail
) == error_mark_node
)
701 regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
703 i
= decode_reg_name (regname
);
704 if (i
>= 0 || i
== -4)
707 error ("unknown register name %qs in %<asm%>", regname
);
709 /* Mark clobbered registers. */
712 /* Clobbering the PIC register is an error. */
713 if (i
== (int) PIC_OFFSET_TABLE_REGNUM
)
715 error ("PIC register %qs clobbered in %<asm%>", regname
);
719 SET_HARD_REG_BIT (clobbered_regs
, i
);
723 /* First pass over inputs and outputs checks validity and sets
724 mark_addressable if needed. */
727 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
729 tree val
= TREE_VALUE (tail
);
730 tree type
= TREE_TYPE (val
);
731 const char *constraint
;
736 /* If there's an erroneous arg, emit no insn. */
737 if (type
== error_mark_node
)
740 /* Try to parse the output constraint. If that fails, there's
741 no point in going further. */
742 constraint
= constraints
[i
];
743 if (!parse_output_constraint (&constraint
, i
, ninputs
, noutputs
,
744 &allows_mem
, &allows_reg
, &is_inout
))
751 && REG_P (DECL_RTL (val
))
752 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
))))
753 lang_hooks
.mark_addressable (val
);
760 if (ninputs
+ noutputs
> MAX_RECOG_OPERANDS
)
762 error ("more than %d operands in %<asm%>", MAX_RECOG_OPERANDS
);
766 for (i
= 0, tail
= inputs
; tail
; i
++, tail
= TREE_CHAIN (tail
))
768 bool allows_reg
, allows_mem
;
769 const char *constraint
;
771 /* If there's an erroneous arg, emit no insn, because the ASM_INPUT
772 would get VOIDmode and that could cause a crash in reload. */
773 if (TREE_TYPE (TREE_VALUE (tail
)) == error_mark_node
)
776 constraint
= constraints
[i
+ noutputs
];
777 if (! parse_input_constraint (&constraint
, i
, ninputs
, noutputs
, ninout
,
778 constraints
, &allows_mem
, &allows_reg
))
781 if (! allows_reg
&& allows_mem
)
782 lang_hooks
.mark_addressable (TREE_VALUE (tail
));
785 /* Second pass evaluates arguments. */
788 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
790 tree val
= TREE_VALUE (tail
);
791 tree type
= TREE_TYPE (val
);
798 ok
= parse_output_constraint (&constraints
[i
], i
, ninputs
,
799 noutputs
, &allows_mem
, &allows_reg
,
803 /* If an output operand is not a decl or indirect ref and our constraint
804 allows a register, make a temporary to act as an intermediate.
805 Make the asm insn write into that, then our caller will copy it to
806 the real output operand. Likewise for promoted variables. */
808 generating_concat_p
= 0;
810 real_output_rtx
[i
] = NULL_RTX
;
811 if ((TREE_CODE (val
) == INDIRECT_REF
814 && (allows_mem
|| REG_P (DECL_RTL (val
)))
815 && ! (REG_P (DECL_RTL (val
))
816 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
)))
820 op
= expand_expr (val
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
822 op
= validize_mem (op
);
824 if (! allows_reg
&& !MEM_P (op
))
825 error ("output number %d not directly addressable", i
);
826 if ((! allows_mem
&& MEM_P (op
))
827 || GET_CODE (op
) == CONCAT
)
829 real_output_rtx
[i
] = op
;
830 op
= gen_reg_rtx (GET_MODE (op
));
832 emit_move_insn (op
, real_output_rtx
[i
]);
837 op
= assign_temp (type
, 0, 0, 1);
838 op
= validize_mem (op
);
839 TREE_VALUE (tail
) = make_tree (type
, op
);
843 generating_concat_p
= old_generating_concat_p
;
847 inout_mode
[ninout
] = TYPE_MODE (type
);
848 inout_opnum
[ninout
++] = i
;
851 if (tree_conflicts_with_clobbers_p (val
, &clobbered_regs
))
852 clobber_conflict_found
= 1;
855 /* Make vectors for the expression-rtx, constraint strings,
856 and named operands. */
858 argvec
= rtvec_alloc (ninputs
);
859 constraintvec
= rtvec_alloc (ninputs
);
861 body
= gen_rtx_ASM_OPERANDS ((noutputs
== 0 ? VOIDmode
862 : GET_MODE (output_rtx
[0])),
863 ggc_strdup (TREE_STRING_POINTER (string
)),
864 empty_string
, 0, argvec
, constraintvec
,
867 MEM_VOLATILE_P (body
) = vol
;
869 /* Eval the inputs and put them into ARGVEC.
870 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
872 for (i
= 0, tail
= inputs
; tail
; tail
= TREE_CHAIN (tail
), ++i
)
874 bool allows_reg
, allows_mem
;
875 const char *constraint
;
880 constraint
= constraints
[i
+ noutputs
];
881 ok
= parse_input_constraint (&constraint
, i
, ninputs
, noutputs
, ninout
,
882 constraints
, &allows_mem
, &allows_reg
);
885 generating_concat_p
= 0;
887 val
= TREE_VALUE (tail
);
888 type
= TREE_TYPE (val
);
889 /* EXPAND_INITIALIZER will not generate code for valid initializer
890 constants, but will still generate code for other types of operand.
891 This is the behavior we want for constant constraints. */
892 op
= expand_expr (val
, NULL_RTX
, VOIDmode
,
893 allows_reg
? EXPAND_NORMAL
894 : allows_mem
? EXPAND_MEMORY
895 : EXPAND_INITIALIZER
);
897 /* Never pass a CONCAT to an ASM. */
898 if (GET_CODE (op
) == CONCAT
)
899 op
= force_reg (GET_MODE (op
), op
);
901 op
= validize_mem (op
);
903 if (asm_operand_ok (op
, constraint
) <= 0)
905 if (allows_reg
&& TYPE_MODE (type
) != BLKmode
)
906 op
= force_reg (TYPE_MODE (type
), op
);
907 else if (!allows_mem
)
908 warning (0, "asm operand %d probably doesn%'t match constraints",
912 /* We won't recognize either volatile memory or memory
913 with a queued address as available a memory_operand
914 at this point. Ignore it: clearly this *is* a memory. */
918 warning (0, "use of memory input without lvalue in "
919 "asm operand %d is deprecated", i
+ noutputs
);
923 rtx mem
= force_const_mem (TYPE_MODE (type
), op
);
925 op
= validize_mem (mem
);
927 op
= force_reg (TYPE_MODE (type
), op
);
930 || GET_CODE (op
) == SUBREG
931 || GET_CODE (op
) == CONCAT
)
933 tree qual_type
= build_qualified_type (type
,
936 rtx memloc
= assign_temp (qual_type
, 1, 1, 1);
937 memloc
= validize_mem (memloc
);
938 emit_move_insn (memloc
, op
);
944 generating_concat_p
= old_generating_concat_p
;
945 ASM_OPERANDS_INPUT (body
, i
) = op
;
947 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body
, i
)
948 = gen_rtx_ASM_INPUT (TYPE_MODE (type
),
949 ggc_strdup (constraints
[i
+ noutputs
]));
951 if (tree_conflicts_with_clobbers_p (val
, &clobbered_regs
))
952 clobber_conflict_found
= 1;
955 /* Protect all the operands from the queue now that they have all been
958 generating_concat_p
= 0;
960 /* For in-out operands, copy output rtx to input rtx. */
961 for (i
= 0; i
< ninout
; i
++)
963 int j
= inout_opnum
[i
];
966 ASM_OPERANDS_INPUT (body
, ninputs
- ninout
+ i
)
969 sprintf (buffer
, "%d", j
);
970 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body
, ninputs
- ninout
+ i
)
971 = gen_rtx_ASM_INPUT (inout_mode
[i
], ggc_strdup (buffer
));
974 generating_concat_p
= old_generating_concat_p
;
976 /* Now, for each output, construct an rtx
977 (set OUTPUT (asm_operands INSN OUTPUTCONSTRAINT OUTPUTNUMBER
978 ARGVEC CONSTRAINTS OPNAMES))
979 If there is more than one, put them inside a PARALLEL. */
981 if (noutputs
== 1 && nclobbers
== 0)
983 ASM_OPERANDS_OUTPUT_CONSTRAINT (body
) = ggc_strdup (constraints
[0]);
984 emit_insn (gen_rtx_SET (VOIDmode
, output_rtx
[0], body
));
987 else if (noutputs
== 0 && nclobbers
== 0)
989 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1001 body
= gen_rtx_PARALLEL (VOIDmode
, rtvec_alloc (num
+ nclobbers
));
1003 /* For each output operand, store a SET. */
1004 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1006 XVECEXP (body
, 0, i
)
1007 = gen_rtx_SET (VOIDmode
,
1009 gen_rtx_ASM_OPERANDS
1010 (GET_MODE (output_rtx
[i
]),
1011 ggc_strdup (TREE_STRING_POINTER (string
)),
1012 ggc_strdup (constraints
[i
]),
1013 i
, argvec
, constraintvec
, locus
));
1015 MEM_VOLATILE_P (SET_SRC (XVECEXP (body
, 0, i
))) = vol
;
1018 /* If there are no outputs (but there are some clobbers)
1019 store the bare ASM_OPERANDS into the PARALLEL. */
1022 XVECEXP (body
, 0, i
++) = obody
;
1024 /* Store (clobber REG) for each clobbered register specified. */
1026 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1028 const char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1029 int j
= decode_reg_name (regname
);
1034 if (j
== -3) /* `cc', which is not a register */
1037 if (j
== -4) /* `memory', don't cache memory across asm */
1039 XVECEXP (body
, 0, i
++)
1040 = gen_rtx_CLOBBER (VOIDmode
,
1043 gen_rtx_SCRATCH (VOIDmode
)));
1047 /* Ignore unknown register, error already signaled. */
1051 /* Use QImode since that's guaranteed to clobber just one reg. */
1052 clobbered_reg
= gen_rtx_REG (QImode
, j
);
1054 /* Do sanity check for overlap between clobbers and respectively
1055 input and outputs that hasn't been handled. Such overlap
1056 should have been detected and reported above. */
1057 if (!clobber_conflict_found
)
1061 /* We test the old body (obody) contents to avoid tripping
1062 over the under-construction body. */
1063 for (opno
= 0; opno
< noutputs
; opno
++)
1064 if (reg_overlap_mentioned_p (clobbered_reg
, output_rtx
[opno
]))
1065 internal_error ("asm clobber conflict with output operand");
1067 for (opno
= 0; opno
< ninputs
- ninout
; opno
++)
1068 if (reg_overlap_mentioned_p (clobbered_reg
,
1069 ASM_OPERANDS_INPUT (obody
, opno
)))
1070 internal_error ("asm clobber conflict with input operand");
1073 XVECEXP (body
, 0, i
++)
1074 = gen_rtx_CLOBBER (VOIDmode
, clobbered_reg
);
1080 /* For any outputs that needed reloading into registers, spill them
1081 back to where they belong. */
1082 for (i
= 0; i
< noutputs
; ++i
)
1083 if (real_output_rtx
[i
])
1084 emit_move_insn (real_output_rtx
[i
], output_rtx
[i
]);
1090 expand_asm_expr (tree exp
)
1096 if (ASM_INPUT_P (exp
))
1098 expand_asm_loc (ASM_STRING (exp
), ASM_VOLATILE_P (exp
), input_location
);
1102 outputs
= ASM_OUTPUTS (exp
);
1103 noutputs
= list_length (outputs
);
1104 /* o[I] is the place that output number I should be written. */
1105 o
= (tree
*) alloca (noutputs
* sizeof (tree
));
1107 /* Record the contents of OUTPUTS before it is modified. */
1108 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1109 o
[i
] = TREE_VALUE (tail
);
1111 /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
1112 OUTPUTS some trees for where the values were actually stored. */
1113 expand_asm_operands (ASM_STRING (exp
), outputs
, ASM_INPUTS (exp
),
1114 ASM_CLOBBERS (exp
), ASM_VOLATILE_P (exp
),
1117 /* Copy all the intermediate outputs into the specified outputs. */
1118 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1120 if (o
[i
] != TREE_VALUE (tail
))
1122 expand_assignment (o
[i
], TREE_VALUE (tail
));
1125 /* Restore the original value so that it's correct the next
1126 time we expand this function. */
1127 TREE_VALUE (tail
) = o
[i
];
1132 /* A subroutine of expand_asm_operands. Check that all operands have
1133 the same number of alternatives. Return true if so. */
1136 check_operand_nalternatives (tree outputs
, tree inputs
)
1138 if (outputs
|| inputs
)
1140 tree tmp
= TREE_PURPOSE (outputs
? outputs
: inputs
);
1142 = n_occurrences (',', TREE_STRING_POINTER (TREE_VALUE (tmp
)));
1145 if (nalternatives
+ 1 > MAX_RECOG_ALTERNATIVES
)
1147 error ("too many alternatives in %<asm%>");
1154 const char *constraint
1155 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tmp
)));
1157 if (n_occurrences (',', constraint
) != nalternatives
)
1159 error ("operand constraints for %<asm%> differ "
1160 "in number of alternatives");
1164 if (TREE_CHAIN (tmp
))
1165 tmp
= TREE_CHAIN (tmp
);
1167 tmp
= next
, next
= 0;
1174 /* A subroutine of expand_asm_operands. Check that all operand names
1175 are unique. Return true if so. We rely on the fact that these names
1176 are identifiers, and so have been canonicalized by get_identifier,
1177 so all we need are pointer comparisons. */
1180 check_unique_operand_names (tree outputs
, tree inputs
)
1184 for (i
= outputs
; i
; i
= TREE_CHAIN (i
))
1186 tree i_name
= TREE_PURPOSE (TREE_PURPOSE (i
));
1190 for (j
= TREE_CHAIN (i
); j
; j
= TREE_CHAIN (j
))
1191 if (simple_cst_equal (i_name
, TREE_PURPOSE (TREE_PURPOSE (j
))))
1195 for (i
= inputs
; i
; i
= TREE_CHAIN (i
))
1197 tree i_name
= TREE_PURPOSE (TREE_PURPOSE (i
));
1201 for (j
= TREE_CHAIN (i
); j
; j
= TREE_CHAIN (j
))
1202 if (simple_cst_equal (i_name
, TREE_PURPOSE (TREE_PURPOSE (j
))))
1204 for (j
= outputs
; j
; j
= TREE_CHAIN (j
))
1205 if (simple_cst_equal (i_name
, TREE_PURPOSE (TREE_PURPOSE (j
))))
1212 error ("duplicate asm operand name %qs",
1213 TREE_STRING_POINTER (TREE_PURPOSE (TREE_PURPOSE (i
))));
1217 /* A subroutine of expand_asm_operands. Resolve the names of the operands
1218 in *POUTPUTS and *PINPUTS to numbers, and replace the name expansions in
1219 STRING and in the constraints to those numbers. */
1222 resolve_asm_operand_names (tree string
, tree outputs
, tree inputs
)
1229 check_unique_operand_names (outputs
, inputs
);
1231 /* Substitute [<name>] in input constraint strings. There should be no
1232 named operands in output constraints. */
1233 for (t
= inputs
; t
; t
= TREE_CHAIN (t
))
1235 c
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t
)));
1236 if (strchr (c
, '[') != NULL
)
1238 p
= buffer
= xstrdup (c
);
1239 while ((p
= strchr (p
, '[')) != NULL
)
1240 p
= resolve_operand_name_1 (p
, outputs
, inputs
);
1241 TREE_VALUE (TREE_PURPOSE (t
))
1242 = build_string (strlen (buffer
), buffer
);
1247 /* Now check for any needed substitutions in the template. */
1248 c
= TREE_STRING_POINTER (string
);
1249 while ((c
= strchr (c
, '%')) != NULL
)
1253 else if (ISALPHA (c
[1]) && c
[2] == '[')
1264 /* OK, we need to make a copy so we can perform the substitutions.
1265 Assume that we will not need extra space--we get to remove '['
1266 and ']', which means we cannot have a problem until we have more
1267 than 999 operands. */
1268 buffer
= xstrdup (TREE_STRING_POINTER (string
));
1269 p
= buffer
+ (c
- TREE_STRING_POINTER (string
));
1271 while ((p
= strchr (p
, '%')) != NULL
)
1275 else if (ISALPHA (p
[1]) && p
[2] == '[')
1283 p
= resolve_operand_name_1 (p
, outputs
, inputs
);
1286 string
= build_string (strlen (buffer
), buffer
);
1293 /* A subroutine of resolve_operand_names. P points to the '[' for a
1294 potential named operand of the form [<name>]. In place, replace
1295 the name and brackets with a number. Return a pointer to the
1296 balance of the string after substitution. */
1299 resolve_operand_name_1 (char *p
, tree outputs
, tree inputs
)
1306 /* Collect the operand name. */
1307 q
= strchr (p
, ']');
1310 error ("missing close brace for named operand");
1311 return strchr (p
, '\0');
1315 /* Resolve the name to a number. */
1316 for (op
= 0, t
= outputs
; t
; t
= TREE_CHAIN (t
), op
++)
1318 tree name
= TREE_PURPOSE (TREE_PURPOSE (t
));
1321 const char *c
= TREE_STRING_POINTER (name
);
1322 if (strncmp (c
, p
+ 1, len
) == 0 && c
[len
] == '\0')
1326 for (t
= inputs
; t
; t
= TREE_CHAIN (t
), op
++)
1328 tree name
= TREE_PURPOSE (TREE_PURPOSE (t
));
1331 const char *c
= TREE_STRING_POINTER (name
);
1332 if (strncmp (c
, p
+ 1, len
) == 0 && c
[len
] == '\0')
1338 error ("undefined named operand %qs", p
+ 1);
1342 /* Replace the name with the number. Unfortunately, not all libraries
1343 get the return value of sprintf correct, so search for the end of the
1344 generated string by hand. */
1345 sprintf (p
, "%d", op
);
1346 p
= strchr (p
, '\0');
1348 /* Verify the no extra buffer space assumption. */
1349 gcc_assert (p
<= q
);
1351 /* Shift the rest of the buffer down to fill the gap. */
1352 memmove (p
, q
+ 1, strlen (q
+ 1) + 1);
1357 /* Generate RTL to evaluate the expression EXP. */
1360 expand_expr_stmt (tree exp
)
1365 value
= expand_expr (exp
, const0_rtx
, VOIDmode
, 0);
1366 if (GIMPLE_TUPLE_P (exp
))
1367 type
= void_type_node
;
1369 type
= TREE_TYPE (exp
);
1371 /* If all we do is reference a volatile value in memory,
1372 copy it to a register to be sure it is actually touched. */
1373 if (value
&& MEM_P (value
) && TREE_THIS_VOLATILE (exp
))
1375 if (TYPE_MODE (type
) == VOIDmode
)
1377 else if (TYPE_MODE (type
) != BLKmode
)
1378 value
= copy_to_reg (value
);
1381 rtx lab
= gen_label_rtx ();
1383 /* Compare the value with itself to reference it. */
1384 emit_cmp_and_jump_insns (value
, value
, EQ
,
1385 expand_normal (TYPE_SIZE (type
)),
1391 /* Free any temporaries used to evaluate this expression. */
1395 /* Warn if EXP contains any computations whose results are not used.
1396 Return 1 if a warning is printed; 0 otherwise. LOCUS is the
1397 (potential) location of the expression. */
1400 warn_if_unused_value (tree exp
, location_t locus
)
1403 if (TREE_USED (exp
) || TREE_NO_WARNING (exp
))
1406 /* Don't warn about void constructs. This includes casting to void,
1407 void function calls, and statement expressions with a final cast
1409 if (VOID_TYPE_P (TREE_TYPE (exp
)))
1412 if (EXPR_HAS_LOCATION (exp
))
1413 locus
= EXPR_LOCATION (exp
);
1415 switch (TREE_CODE (exp
))
1417 case PREINCREMENT_EXPR
:
1418 case POSTINCREMENT_EXPR
:
1419 case PREDECREMENT_EXPR
:
1420 case POSTDECREMENT_EXPR
:
1422 case GIMPLE_MODIFY_STMT
:
1426 case TRY_CATCH_EXPR
:
1427 case WITH_CLEANUP_EXPR
:
1433 /* For a binding, warn if no side effect within it. */
1434 exp
= BIND_EXPR_BODY (exp
);
1438 exp
= TREE_OPERAND (exp
, 0);
1441 case TRUTH_ORIF_EXPR
:
1442 case TRUTH_ANDIF_EXPR
:
1443 /* In && or ||, warn if 2nd operand has no side effect. */
1444 exp
= TREE_OPERAND (exp
, 1);
1448 if (warn_if_unused_value (TREE_OPERAND (exp
, 0), locus
))
1450 /* Let people do `(foo (), 0)' without a warning. */
1451 if (TREE_CONSTANT (TREE_OPERAND (exp
, 1)))
1453 exp
= TREE_OPERAND (exp
, 1);
1457 /* If this is an expression with side effects, don't warn; this
1458 case commonly appears in macro expansions. */
1459 if (TREE_SIDE_EFFECTS (exp
))
1464 /* Don't warn about automatic dereferencing of references, since
1465 the user cannot control it. */
1466 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp
, 0))) == REFERENCE_TYPE
)
1468 exp
= TREE_OPERAND (exp
, 0);
1474 /* Referencing a volatile value is a side effect, so don't warn. */
1475 if ((DECL_P (exp
) || REFERENCE_CLASS_P (exp
))
1476 && TREE_THIS_VOLATILE (exp
))
1479 /* If this is an expression which has no operands, there is no value
1480 to be unused. There are no such language-independent codes,
1481 but front ends may define such. */
1482 if (EXPRESSION_CLASS_P (exp
) && TREE_OPERAND_LENGTH (exp
) == 0)
1486 warning (0, "%Hvalue computed is not used", &locus
);
1492 /* Generate RTL to return from the current function, with no value.
1493 (That is, we do not do anything about returning any value.) */
1496 expand_null_return (void)
1498 /* If this function was declared to return a value, but we
1499 didn't, clobber the return registers so that they are not
1500 propagated live to the rest of the function. */
1501 clobber_return_register ();
1503 expand_null_return_1 ();
1506 /* Generate RTL to return directly from the current function.
1507 (That is, we bypass any return value.) */
1510 expand_naked_return (void)
1514 clear_pending_stack_adjust ();
1515 do_pending_stack_adjust ();
1517 end_label
= naked_return_label
;
1519 end_label
= naked_return_label
= gen_label_rtx ();
1521 emit_jump (end_label
);
1524 /* Generate RTL to return from the current function, with value VAL. */
1527 expand_value_return (rtx val
)
1529 /* Copy the value to the return location
1530 unless it's already there. */
1532 rtx return_reg
= DECL_RTL (DECL_RESULT (current_function_decl
));
1533 if (return_reg
!= val
)
1535 tree type
= TREE_TYPE (DECL_RESULT (current_function_decl
));
1536 if (targetm
.calls
.promote_function_return (TREE_TYPE (current_function_decl
)))
1538 int unsignedp
= TYPE_UNSIGNED (type
);
1539 enum machine_mode old_mode
1540 = DECL_MODE (DECL_RESULT (current_function_decl
));
1541 enum machine_mode mode
1542 = promote_mode (type
, old_mode
, &unsignedp
, 1);
1544 if (mode
!= old_mode
)
1545 val
= convert_modes (mode
, old_mode
, val
, unsignedp
);
1547 if (GET_CODE (return_reg
) == PARALLEL
)
1548 emit_group_load (return_reg
, val
, type
, int_size_in_bytes (type
));
1550 emit_move_insn (return_reg
, val
);
1553 expand_null_return_1 ();
1556 /* Output a return with no value. */
1559 expand_null_return_1 (void)
1561 clear_pending_stack_adjust ();
1562 do_pending_stack_adjust ();
1563 emit_jump (return_label
);
1566 /* Generate RTL to evaluate the expression RETVAL and return it
1567 from the current function. */
1570 expand_return (tree retval
)
1576 /* If function wants no value, give it none. */
1577 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl
))) == VOID_TYPE
)
1579 expand_normal (retval
);
1580 expand_null_return ();
1584 if (retval
== error_mark_node
)
1586 /* Treat this like a return of no value from a function that
1588 expand_null_return ();
1591 else if ((TREE_CODE (retval
) == GIMPLE_MODIFY_STMT
1592 || TREE_CODE (retval
) == INIT_EXPR
)
1593 && TREE_CODE (GENERIC_TREE_OPERAND (retval
, 0)) == RESULT_DECL
)
1594 retval_rhs
= GENERIC_TREE_OPERAND (retval
, 1);
1596 retval_rhs
= retval
;
1598 result_rtl
= DECL_RTL (DECL_RESULT (current_function_decl
));
1600 /* If we are returning the RESULT_DECL, then the value has already
1601 been stored into it, so we don't have to do anything special. */
1602 if (TREE_CODE (retval_rhs
) == RESULT_DECL
)
1603 expand_value_return (result_rtl
);
1605 /* If the result is an aggregate that is being returned in one (or more)
1606 registers, load the registers here. The compiler currently can't handle
1607 copying a BLKmode value into registers. We could put this code in a
1608 more general area (for use by everyone instead of just function
1609 call/return), but until this feature is generally usable it is kept here
1610 (and in expand_call). */
1612 else if (retval_rhs
!= 0
1613 && TYPE_MODE (GENERIC_TREE_TYPE (retval_rhs
)) == BLKmode
1614 && REG_P (result_rtl
))
1617 unsigned HOST_WIDE_INT bitpos
, xbitpos
;
1618 unsigned HOST_WIDE_INT padding_correction
= 0;
1619 unsigned HOST_WIDE_INT bytes
1620 = int_size_in_bytes (TREE_TYPE (retval_rhs
));
1621 int n_regs
= (bytes
+ UNITS_PER_WORD
- 1) / UNITS_PER_WORD
;
1622 unsigned int bitsize
1623 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs
)), BITS_PER_WORD
);
1624 rtx
*result_pseudos
= alloca (sizeof (rtx
) * n_regs
);
1625 rtx result_reg
, src
= NULL_RTX
, dst
= NULL_RTX
;
1626 rtx result_val
= expand_normal (retval_rhs
);
1627 enum machine_mode tmpmode
, result_reg_mode
;
1631 expand_null_return ();
1635 /* If the structure doesn't take up a whole number of words, see
1636 whether the register value should be padded on the left or on
1637 the right. Set PADDING_CORRECTION to the number of padding
1638 bits needed on the left side.
1640 In most ABIs, the structure will be returned at the least end of
1641 the register, which translates to right padding on little-endian
1642 targets and left padding on big-endian targets. The opposite
1643 holds if the structure is returned at the most significant
1644 end of the register. */
1645 if (bytes
% UNITS_PER_WORD
!= 0
1646 && (targetm
.calls
.return_in_msb (TREE_TYPE (retval_rhs
))
1648 : BYTES_BIG_ENDIAN
))
1649 padding_correction
= (BITS_PER_WORD
- ((bytes
% UNITS_PER_WORD
)
1652 /* Copy the structure BITSIZE bits at a time. */
1653 for (bitpos
= 0, xbitpos
= padding_correction
;
1654 bitpos
< bytes
* BITS_PER_UNIT
;
1655 bitpos
+= bitsize
, xbitpos
+= bitsize
)
1657 /* We need a new destination pseudo each time xbitpos is
1658 on a word boundary and when xbitpos == padding_correction
1659 (the first time through). */
1660 if (xbitpos
% BITS_PER_WORD
== 0
1661 || xbitpos
== padding_correction
)
1663 /* Generate an appropriate register. */
1664 dst
= gen_reg_rtx (word_mode
);
1665 result_pseudos
[xbitpos
/ BITS_PER_WORD
] = dst
;
1667 /* Clear the destination before we move anything into it. */
1668 emit_move_insn (dst
, CONST0_RTX (GET_MODE (dst
)));
1671 /* We need a new source operand each time bitpos is on a word
1673 if (bitpos
% BITS_PER_WORD
== 0)
1674 src
= operand_subword_force (result_val
,
1675 bitpos
/ BITS_PER_WORD
,
1678 /* Use bitpos for the source extraction (left justified) and
1679 xbitpos for the destination store (right justified). */
1680 store_bit_field (dst
, bitsize
, xbitpos
% BITS_PER_WORD
, word_mode
,
1681 extract_bit_field (src
, bitsize
,
1682 bitpos
% BITS_PER_WORD
, 1,
1683 NULL_RTX
, word_mode
, word_mode
));
1686 tmpmode
= GET_MODE (result_rtl
);
1687 if (tmpmode
== BLKmode
)
1689 /* Find the smallest integer mode large enough to hold the
1690 entire structure and use that mode instead of BLKmode
1691 on the USE insn for the return register. */
1692 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
1693 tmpmode
!= VOIDmode
;
1694 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
1695 /* Have we found a large enough mode? */
1696 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
1699 /* A suitable mode should have been found. */
1700 gcc_assert (tmpmode
!= VOIDmode
);
1702 PUT_MODE (result_rtl
, tmpmode
);
1705 if (GET_MODE_SIZE (tmpmode
) < GET_MODE_SIZE (word_mode
))
1706 result_reg_mode
= word_mode
;
1708 result_reg_mode
= tmpmode
;
1709 result_reg
= gen_reg_rtx (result_reg_mode
);
1711 for (i
= 0; i
< n_regs
; i
++)
1712 emit_move_insn (operand_subword (result_reg
, i
, 0, result_reg_mode
),
1715 if (tmpmode
!= result_reg_mode
)
1716 result_reg
= gen_lowpart (tmpmode
, result_reg
);
1718 expand_value_return (result_reg
);
1720 else if (retval_rhs
!= 0
1721 && !VOID_TYPE_P (TREE_TYPE (retval_rhs
))
1722 && (REG_P (result_rtl
)
1723 || (GET_CODE (result_rtl
) == PARALLEL
)))
1725 /* Calculate the return value into a temporary (usually a pseudo
1727 tree ot
= TREE_TYPE (DECL_RESULT (current_function_decl
));
1728 tree nt
= build_qualified_type (ot
, TYPE_QUALS (ot
) | TYPE_QUAL_CONST
);
1730 val
= assign_temp (nt
, 0, 0, 1);
1731 val
= expand_expr (retval_rhs
, val
, GET_MODE (val
), 0);
1732 val
= force_not_mem (val
);
1733 /* Return the calculated value. */
1734 expand_value_return (val
);
1738 /* No hard reg used; calculate value into hard return reg. */
1739 expand_expr (retval
, const0_rtx
, VOIDmode
, 0);
1740 expand_value_return (result_rtl
);
1744 /* Given a pointer to a BLOCK node return nonzero if (and only if) the node
1745 in question represents the outermost pair of curly braces (i.e. the "body
1746 block") of a function or method.
1748 For any BLOCK node representing a "body block" of a function or method, the
1749 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
1750 represents the outermost (function) scope for the function or method (i.e.
1751 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
1752 *that* node in turn will point to the relevant FUNCTION_DECL node. */
1755 is_body_block (tree stmt
)
1757 if (lang_hooks
.no_body_blocks
)
1760 if (TREE_CODE (stmt
) == BLOCK
)
1762 tree parent
= BLOCK_SUPERCONTEXT (stmt
);
1764 if (parent
&& TREE_CODE (parent
) == BLOCK
)
1766 tree grandparent
= BLOCK_SUPERCONTEXT (parent
);
1768 if (grandparent
&& TREE_CODE (grandparent
) == FUNCTION_DECL
)
1776 /* Emit code to restore vital registers at the beginning of a nonlocal goto
1779 expand_nl_goto_receiver (void)
1781 /* Clobber the FP when we get here, so we have to make sure it's
1782 marked as used by this function. */
1783 emit_insn (gen_rtx_USE (VOIDmode
, hard_frame_pointer_rtx
));
1785 /* Mark the static chain as clobbered here so life information
1786 doesn't get messed up for it. */
1787 emit_insn (gen_rtx_CLOBBER (VOIDmode
, static_chain_rtx
));
1789 #ifdef HAVE_nonlocal_goto
1790 if (! HAVE_nonlocal_goto
)
1792 /* First adjust our frame pointer to its actual value. It was
1793 previously set to the start of the virtual area corresponding to
1794 the stacked variables when we branched here and now needs to be
1795 adjusted to the actual hardware fp value.
1797 Assignments are to virtual registers are converted by
1798 instantiate_virtual_regs into the corresponding assignment
1799 to the underlying register (fp in this case) that makes
1800 the original assignment true.
1801 So the following insn will actually be
1802 decrementing fp by STARTING_FRAME_OFFSET. */
1803 emit_move_insn (virtual_stack_vars_rtx
, hard_frame_pointer_rtx
);
1805 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
1806 if (fixed_regs
[ARG_POINTER_REGNUM
])
1808 #ifdef ELIMINABLE_REGS
1809 /* If the argument pointer can be eliminated in favor of the
1810 frame pointer, we don't need to restore it. We assume here
1811 that if such an elimination is present, it can always be used.
1812 This is the case on all known machines; if we don't make this
1813 assumption, we do unnecessary saving on many machines. */
1814 static const struct elims
{const int from
, to
;} elim_regs
[] = ELIMINABLE_REGS
;
1817 for (i
= 0; i
< ARRAY_SIZE (elim_regs
); i
++)
1818 if (elim_regs
[i
].from
== ARG_POINTER_REGNUM
1819 && elim_regs
[i
].to
== HARD_FRAME_POINTER_REGNUM
)
1822 if (i
== ARRAY_SIZE (elim_regs
))
1825 /* Now restore our arg pointer from the address at which it
1826 was saved in our stack frame. */
1827 emit_move_insn (virtual_incoming_args_rtx
,
1828 copy_to_reg (get_arg_pointer_save_area (cfun
)));
1833 #ifdef HAVE_nonlocal_goto_receiver
1834 if (HAVE_nonlocal_goto_receiver
)
1835 emit_insn (gen_nonlocal_goto_receiver ());
1838 /* @@@ This is a kludge. Not all machine descriptions define a blockage
1839 insn, but we must not allow the code we just generated to be reordered
1840 by scheduling. Specifically, the update of the frame pointer must
1841 happen immediately, not later. So emit an ASM_INPUT to act as blockage
1843 emit_insn (gen_rtx_ASM_INPUT (VOIDmode
, ""));
1846 /* Generate RTL for the automatic variable declaration DECL.
1847 (Other kinds of declarations are simply ignored if seen here.) */
1850 expand_decl (tree decl
)
1854 type
= TREE_TYPE (decl
);
1856 /* For a CONST_DECL, set mode, alignment, and sizes from those of the
1857 type in case this node is used in a reference. */
1858 if (TREE_CODE (decl
) == CONST_DECL
)
1860 DECL_MODE (decl
) = TYPE_MODE (type
);
1861 DECL_ALIGN (decl
) = TYPE_ALIGN (type
);
1862 DECL_SIZE (decl
) = TYPE_SIZE (type
);
1863 DECL_SIZE_UNIT (decl
) = TYPE_SIZE_UNIT (type
);
1867 /* Otherwise, only automatic variables need any expansion done. Static and
1868 external variables, and external functions, will be handled by
1869 `assemble_variable' (called from finish_decl). TYPE_DECL requires
1870 nothing. PARM_DECLs are handled in `assign_parms'. */
1871 if (TREE_CODE (decl
) != VAR_DECL
)
1874 if (TREE_STATIC (decl
) || DECL_EXTERNAL (decl
))
1877 /* Create the RTL representation for the variable. */
1879 if (type
== error_mark_node
)
1880 SET_DECL_RTL (decl
, gen_rtx_MEM (BLKmode
, const0_rtx
));
1882 else if (DECL_SIZE (decl
) == 0)
1883 /* Variable with incomplete type. */
1886 if (DECL_INITIAL (decl
) == 0)
1887 /* Error message was already done; now avoid a crash. */
1888 x
= gen_rtx_MEM (BLKmode
, const0_rtx
);
1890 /* An initializer is going to decide the size of this array.
1891 Until we know the size, represent its address with a reg. */
1892 x
= gen_rtx_MEM (BLKmode
, gen_reg_rtx (Pmode
));
1894 set_mem_attributes (x
, decl
, 1);
1895 SET_DECL_RTL (decl
, x
);
1897 else if (use_register_for_decl (decl
))
1899 /* Automatic variable that can go in a register. */
1900 int unsignedp
= TYPE_UNSIGNED (type
);
1901 enum machine_mode reg_mode
1902 = promote_mode (type
, DECL_MODE (decl
), &unsignedp
, 0);
1904 SET_DECL_RTL (decl
, gen_reg_rtx (reg_mode
));
1906 /* Note if the object is a user variable. */
1907 if (!DECL_ARTIFICIAL (decl
))
1909 mark_user_reg (DECL_RTL (decl
));
1911 /* Trust user variables which have a pointer type to really
1912 be pointers. Do not trust compiler generated temporaries
1913 as our type system is totally busted as it relates to
1914 pointer arithmetic which translates into lots of compiler
1915 generated objects with pointer types, but which are not really
1917 if (POINTER_TYPE_P (type
))
1918 mark_reg_pointer (DECL_RTL (decl
),
1919 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl
))));
1923 else if (TREE_CODE (DECL_SIZE_UNIT (decl
)) == INTEGER_CST
1924 && ! (flag_stack_check
&& ! STACK_CHECK_BUILTIN
1925 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl
),
1926 STACK_CHECK_MAX_VAR_SIZE
)))
1928 /* Variable of fixed size that goes on the stack. */
1933 /* If we previously made RTL for this decl, it must be an array
1934 whose size was determined by the initializer.
1935 The old address was a register; set that register now
1936 to the proper address. */
1937 if (DECL_RTL_SET_P (decl
))
1939 gcc_assert (MEM_P (DECL_RTL (decl
)));
1940 gcc_assert (REG_P (XEXP (DECL_RTL (decl
), 0)));
1941 oldaddr
= XEXP (DECL_RTL (decl
), 0);
1944 /* Set alignment we actually gave this decl. */
1945 DECL_ALIGN (decl
) = (DECL_MODE (decl
) == BLKmode
? BIGGEST_ALIGNMENT
1946 : GET_MODE_BITSIZE (DECL_MODE (decl
)));
1947 DECL_USER_ALIGN (decl
) = 0;
1949 x
= assign_temp (decl
, 1, 1, 1);
1950 set_mem_attributes (x
, decl
, 1);
1951 SET_DECL_RTL (decl
, x
);
1955 addr
= force_operand (XEXP (DECL_RTL (decl
), 0), oldaddr
);
1956 if (addr
!= oldaddr
)
1957 emit_move_insn (oldaddr
, addr
);
1961 /* Dynamic-size object: must push space on the stack. */
1963 rtx address
, size
, x
;
1965 /* Record the stack pointer on entry to block, if have
1966 not already done so. */
1967 do_pending_stack_adjust ();
1969 /* Compute the variable's size, in bytes. This will expand any
1970 needed SAVE_EXPRs for the first time. */
1971 size
= expand_normal (DECL_SIZE_UNIT (decl
));
1974 /* Allocate space on the stack for the variable. Note that
1975 DECL_ALIGN says how the variable is to be aligned and we
1976 cannot use it to conclude anything about the alignment of
1978 address
= allocate_dynamic_stack_space (size
, NULL_RTX
,
1979 TYPE_ALIGN (TREE_TYPE (decl
)));
1981 /* Reference the variable indirect through that rtx. */
1982 x
= gen_rtx_MEM (DECL_MODE (decl
), address
);
1983 set_mem_attributes (x
, decl
, 1);
1984 SET_DECL_RTL (decl
, x
);
1987 /* Indicate the alignment we actually gave this variable. */
1988 #ifdef STACK_BOUNDARY
1989 DECL_ALIGN (decl
) = STACK_BOUNDARY
;
1991 DECL_ALIGN (decl
) = BIGGEST_ALIGNMENT
;
1993 DECL_USER_ALIGN (decl
) = 0;
1997 /* Emit code to save the current value of stack. */
1999 expand_stack_save (void)
2003 do_pending_stack_adjust ();
2004 emit_stack_save (SAVE_BLOCK
, &ret
, NULL_RTX
);
2008 /* Emit code to restore the current value of stack. */
2010 expand_stack_restore (tree var
)
2012 rtx sa
= DECL_RTL (var
);
2014 emit_stack_restore (SAVE_BLOCK
, sa
, NULL_RTX
);
2017 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
2018 DECL_ELTS is the list of elements that belong to DECL's type.
2019 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
2022 expand_anon_union_decl (tree decl
, tree cleanup ATTRIBUTE_UNUSED
,
2028 /* If any of the elements are addressable, so is the entire union. */
2029 for (t
= decl_elts
; t
; t
= TREE_CHAIN (t
))
2030 if (TREE_ADDRESSABLE (TREE_VALUE (t
)))
2032 TREE_ADDRESSABLE (decl
) = 1;
2037 x
= DECL_RTL (decl
);
2039 /* Go through the elements, assigning RTL to each. */
2040 for (t
= decl_elts
; t
; t
= TREE_CHAIN (t
))
2042 tree decl_elt
= TREE_VALUE (t
);
2043 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (decl_elt
));
2046 /* If any of the elements are addressable, so is the entire
2048 if (TREE_USED (decl_elt
))
2049 TREE_USED (decl
) = 1;
2051 /* Propagate the union's alignment to the elements. */
2052 DECL_ALIGN (decl_elt
) = DECL_ALIGN (decl
);
2053 DECL_USER_ALIGN (decl_elt
) = DECL_USER_ALIGN (decl
);
2055 /* If the element has BLKmode and the union doesn't, the union is
2056 aligned such that the element doesn't need to have BLKmode, so
2057 change the element's mode to the appropriate one for its size. */
2058 if (mode
== BLKmode
&& DECL_MODE (decl
) != BLKmode
)
2059 DECL_MODE (decl_elt
) = mode
2060 = mode_for_size_tree (DECL_SIZE (decl_elt
), MODE_INT
, 1);
2062 if (mode
== GET_MODE (x
))
2065 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
2066 instead create a new MEM rtx with the proper mode. */
2067 decl_rtl
= adjust_address_nv (x
, mode
, 0);
2070 gcc_assert (REG_P (x
));
2071 decl_rtl
= gen_lowpart_SUBREG (mode
, x
);
2073 SET_DECL_RTL (decl_elt
, decl_rtl
);
2077 /* Do the insertion of a case label into case_list. The labels are
2078 fed to us in descending order from the sorted vector of case labels used
2079 in the tree part of the middle end. So the list we construct is
2080 sorted in ascending order. The bounds on the case range, LOW and HIGH,
2081 are converted to case's index type TYPE. */
2083 static struct case_node
*
2084 add_case_node (struct case_node
*head
, tree type
, tree low
, tree high
,
2087 tree min_value
, max_value
;
2088 struct case_node
*r
;
2090 gcc_assert (TREE_CODE (low
) == INTEGER_CST
);
2091 gcc_assert (!high
|| TREE_CODE (high
) == INTEGER_CST
);
2093 min_value
= TYPE_MIN_VALUE (type
);
2094 max_value
= TYPE_MAX_VALUE (type
);
2096 /* If there's no HIGH value, then this is not a case range; it's
2097 just a simple case label. But that's just a degenerate case
2099 If the bounds are equal, turn this into the one-value case. */
2100 if (!high
|| tree_int_cst_equal (low
, high
))
2102 /* If the simple case value is unreachable, ignore it. */
2103 if ((TREE_CODE (min_value
) == INTEGER_CST
2104 && tree_int_cst_compare (low
, min_value
) < 0)
2105 || (TREE_CODE (max_value
) == INTEGER_CST
2106 && tree_int_cst_compare (low
, max_value
) > 0))
2108 low
= fold_convert (type
, low
);
2113 /* If the entire case range is unreachable, ignore it. */
2114 if ((TREE_CODE (min_value
) == INTEGER_CST
2115 && tree_int_cst_compare (high
, min_value
) < 0)
2116 || (TREE_CODE (max_value
) == INTEGER_CST
2117 && tree_int_cst_compare (low
, max_value
) > 0))
2120 /* If the lower bound is less than the index type's minimum
2121 value, truncate the range bounds. */
2122 if (TREE_CODE (min_value
) == INTEGER_CST
2123 && tree_int_cst_compare (low
, min_value
) < 0)
2125 low
= fold_convert (type
, low
);
2127 /* If the upper bound is greater than the index type's maximum
2128 value, truncate the range bounds. */
2129 if (TREE_CODE (max_value
) == INTEGER_CST
2130 && tree_int_cst_compare (high
, max_value
) > 0)
2132 high
= fold_convert (type
, high
);
2136 /* Add this label to the chain. Make sure to drop overflow flags. */
2137 r
= ggc_alloc (sizeof (struct case_node
));
2138 r
->low
= build_int_cst_wide (TREE_TYPE (low
), TREE_INT_CST_LOW (low
),
2139 TREE_INT_CST_HIGH (low
));
2140 r
->high
= build_int_cst_wide (TREE_TYPE (high
), TREE_INT_CST_LOW (high
),
2141 TREE_INT_CST_HIGH (high
));
2142 r
->code_label
= label
;
2143 r
->parent
= r
->left
= NULL
;
2148 /* Maximum number of case bit tests. */
2149 #define MAX_CASE_BIT_TESTS 3
2151 /* By default, enable case bit tests on targets with ashlsi3. */
2152 #ifndef CASE_USE_BIT_TESTS
2153 #define CASE_USE_BIT_TESTS (ashl_optab->handlers[word_mode].insn_code \
2154 != CODE_FOR_nothing)
2158 /* A case_bit_test represents a set of case nodes that may be
2159 selected from using a bit-wise comparison. HI and LO hold
2160 the integer to be tested against, LABEL contains the label
2161 to jump to upon success and BITS counts the number of case
2162 nodes handled by this test, typically the number of bits
2165 struct case_bit_test
2173 /* Determine whether "1 << x" is relatively cheap in word_mode. */
2176 bool lshift_cheap_p (void)
2178 static bool init
= false;
2179 static bool cheap
= true;
2183 rtx reg
= gen_rtx_REG (word_mode
, 10000);
2184 int cost
= rtx_cost (gen_rtx_ASHIFT (word_mode
, const1_rtx
, reg
), SET
);
2185 cheap
= cost
< COSTS_N_INSNS (3);
2192 /* Comparison function for qsort to order bit tests by decreasing
2193 number of case nodes, i.e. the node with the most cases gets
2197 case_bit_test_cmp (const void *p1
, const void *p2
)
2199 const struct case_bit_test
*d1
= p1
;
2200 const struct case_bit_test
*d2
= p2
;
2202 if (d2
->bits
!= d1
->bits
)
2203 return d2
->bits
- d1
->bits
;
2205 /* Stabilize the sort. */
2206 return CODE_LABEL_NUMBER (d2
->label
) - CODE_LABEL_NUMBER (d1
->label
);
2209 /* Expand a switch statement by a short sequence of bit-wise
2210 comparisons. "switch(x)" is effectively converted into
2211 "if ((1 << (x-MINVAL)) & CST)" where CST and MINVAL are
2214 INDEX_EXPR is the value being switched on, which is of
2215 type INDEX_TYPE. MINVAL is the lowest case value of in
2216 the case nodes, of INDEX_TYPE type, and RANGE is highest
2217 value minus MINVAL, also of type INDEX_TYPE. NODES is
2218 the set of case nodes, and DEFAULT_LABEL is the label to
2219 branch to should none of the cases match.
2221 There *MUST* be MAX_CASE_BIT_TESTS or less unique case
2225 emit_case_bit_tests (tree index_type
, tree index_expr
, tree minval
,
2226 tree range
, case_node_ptr nodes
, rtx default_label
)
2228 struct case_bit_test test
[MAX_CASE_BIT_TESTS
];
2229 enum machine_mode mode
;
2230 rtx expr
, index
, label
;
2231 unsigned int i
,j
,lo
,hi
;
2232 struct case_node
*n
;
2236 for (n
= nodes
; n
; n
= n
->right
)
2238 label
= label_rtx (n
->code_label
);
2239 for (i
= 0; i
< count
; i
++)
2240 if (label
== test
[i
].label
)
2245 gcc_assert (count
< MAX_CASE_BIT_TESTS
);
2248 test
[i
].label
= label
;
2255 lo
= tree_low_cst (fold_build2 (MINUS_EXPR
, index_type
,
2256 n
->low
, minval
), 1);
2257 hi
= tree_low_cst (fold_build2 (MINUS_EXPR
, index_type
,
2258 n
->high
, minval
), 1);
2259 for (j
= lo
; j
<= hi
; j
++)
2260 if (j
>= HOST_BITS_PER_WIDE_INT
)
2261 test
[i
].hi
|= (HOST_WIDE_INT
) 1 << (j
- HOST_BITS_PER_INT
);
2263 test
[i
].lo
|= (HOST_WIDE_INT
) 1 << j
;
2266 qsort (test
, count
, sizeof(*test
), case_bit_test_cmp
);
2268 index_expr
= fold_build2 (MINUS_EXPR
, index_type
,
2269 fold_convert (index_type
, index_expr
),
2270 fold_convert (index_type
, minval
));
2271 index
= expand_normal (index_expr
);
2272 do_pending_stack_adjust ();
2274 mode
= TYPE_MODE (index_type
);
2275 expr
= expand_normal (range
);
2276 emit_cmp_and_jump_insns (index
, expr
, GTU
, NULL_RTX
, mode
, 1,
2279 index
= convert_to_mode (word_mode
, index
, 0);
2280 index
= expand_binop (word_mode
, ashl_optab
, const1_rtx
,
2281 index
, NULL_RTX
, 1, OPTAB_WIDEN
);
2283 for (i
= 0; i
< count
; i
++)
2285 expr
= immed_double_const (test
[i
].lo
, test
[i
].hi
, word_mode
);
2286 expr
= expand_binop (word_mode
, and_optab
, index
, expr
,
2287 NULL_RTX
, 1, OPTAB_WIDEN
);
2288 emit_cmp_and_jump_insns (expr
, const0_rtx
, NE
, NULL_RTX
,
2289 word_mode
, 1, test
[i
].label
);
2292 emit_jump (default_label
);
2296 #define HAVE_casesi 0
2299 #ifndef HAVE_tablejump
2300 #define HAVE_tablejump 0
2303 /* Terminate a case (Pascal/Ada) or switch (C) statement
2304 in which ORIG_INDEX is the expression to be tested.
2305 If ORIG_TYPE is not NULL, it is the original ORIG_INDEX
2306 type as given in the source before any compiler conversions.
2307 Generate the code to test it and jump to the right place. */
2310 expand_case (tree exp
)
2312 tree minval
= NULL_TREE
, maxval
= NULL_TREE
, range
= NULL_TREE
;
2313 rtx default_label
= 0;
2314 struct case_node
*n
;
2315 unsigned int count
, uniq
;
2321 rtx before_case
, end
, lab
;
2323 tree vec
= SWITCH_LABELS (exp
);
2324 tree orig_type
= TREE_TYPE (exp
);
2325 tree index_expr
= SWITCH_COND (exp
);
2326 tree index_type
= TREE_TYPE (index_expr
);
2327 int unsignedp
= TYPE_UNSIGNED (index_type
);
2329 /* The insn after which the case dispatch should finally
2330 be emitted. Zero for a dummy. */
2333 /* A list of case labels; it is first built as a list and it may then
2334 be rearranged into a nearly balanced binary tree. */
2335 struct case_node
*case_list
= 0;
2337 /* Label to jump to if no case matches. */
2338 tree default_label_decl
;
2340 /* The switch body is lowered in gimplify.c, we should never have
2341 switches with a non-NULL SWITCH_BODY here. */
2342 gcc_assert (!SWITCH_BODY (exp
));
2343 gcc_assert (SWITCH_LABELS (exp
));
2345 do_pending_stack_adjust ();
2347 /* An ERROR_MARK occurs for various reasons including invalid data type. */
2348 if (index_type
!= error_mark_node
)
2351 bitmap label_bitmap
;
2353 /* cleanup_tree_cfg removes all SWITCH_EXPR with their index
2354 expressions being INTEGER_CST. */
2355 gcc_assert (TREE_CODE (index_expr
) != INTEGER_CST
);
2357 /* The default case is at the end of TREE_VEC. */
2358 elt
= TREE_VEC_ELT (vec
, TREE_VEC_LENGTH (vec
) - 1);
2359 gcc_assert (!CASE_HIGH (elt
));
2360 gcc_assert (!CASE_LOW (elt
));
2361 default_label_decl
= CASE_LABEL (elt
);
2363 for (i
= TREE_VEC_LENGTH (vec
) - 1; --i
>= 0; )
2366 elt
= TREE_VEC_ELT (vec
, i
);
2368 low
= CASE_LOW (elt
);
2370 high
= CASE_HIGH (elt
);
2372 /* Discard empty ranges. */
2373 if (high
&& INT_CST_LT (high
, low
))
2376 case_list
= add_case_node (case_list
, index_type
, low
, high
,
2381 before_case
= start
= get_last_insn ();
2382 default_label
= label_rtx (default_label_decl
);
2384 /* Get upper and lower bounds of case values. */
2388 label_bitmap
= BITMAP_ALLOC (NULL
);
2389 for (n
= case_list
; n
; n
= n
->right
)
2391 /* Count the elements and track the largest and smallest
2392 of them (treating them as signed even if they are not). */
2400 if (INT_CST_LT (n
->low
, minval
))
2402 if (INT_CST_LT (maxval
, n
->high
))
2405 /* A range counts double, since it requires two compares. */
2406 if (! tree_int_cst_equal (n
->low
, n
->high
))
2409 /* If we have not seen this label yet, then increase the
2410 number of unique case node targets seen. */
2411 lab
= label_rtx (n
->code_label
);
2412 if (!bitmap_bit_p (label_bitmap
, CODE_LABEL_NUMBER (lab
)))
2414 bitmap_set_bit (label_bitmap
, CODE_LABEL_NUMBER (lab
));
2419 BITMAP_FREE (label_bitmap
);
2421 /* cleanup_tree_cfg removes all SWITCH_EXPR with a single
2422 destination, such as one with a default case only. However,
2423 it doesn't remove cases that are out of range for the switch
2424 type, so we may still get a zero here. */
2427 emit_jump (default_label
);
2431 /* Compute span of values. */
2432 range
= fold_build2 (MINUS_EXPR
, index_type
, maxval
, minval
);
2434 /* Try implementing this switch statement by a short sequence of
2435 bit-wise comparisons. However, we let the binary-tree case
2436 below handle constant index expressions. */
2437 if (CASE_USE_BIT_TESTS
2438 && ! TREE_CONSTANT (index_expr
)
2439 && compare_tree_int (range
, GET_MODE_BITSIZE (word_mode
)) < 0
2440 && compare_tree_int (range
, 0) > 0
2441 && lshift_cheap_p ()
2442 && ((uniq
== 1 && count
>= 3)
2443 || (uniq
== 2 && count
>= 5)
2444 || (uniq
== 3 && count
>= 6)))
2446 /* Optimize the case where all the case values fit in a
2447 word without having to subtract MINVAL. In this case,
2448 we can optimize away the subtraction. */
2449 if (compare_tree_int (minval
, 0) > 0
2450 && compare_tree_int (maxval
, GET_MODE_BITSIZE (word_mode
)) < 0)
2452 minval
= build_int_cst (index_type
, 0);
2455 emit_case_bit_tests (index_type
, index_expr
, minval
, range
,
2456 case_list
, default_label
);
2459 /* If range of values is much bigger than number of values,
2460 make a sequence of conditional branches instead of a dispatch.
2461 If the switch-index is a constant, do it this way
2462 because we can optimize it. */
2464 else if (count
< case_values_threshold ()
2465 || compare_tree_int (range
,
2466 (optimize_size
? 3 : 10) * count
) > 0
2467 /* RANGE may be signed, and really large ranges will show up
2468 as negative numbers. */
2469 || compare_tree_int (range
, 0) < 0
2470 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
2473 || !flag_jump_tables
2474 || TREE_CONSTANT (index_expr
)
2475 /* If neither casesi or tablejump is available, we can
2476 only go this way. */
2477 || (!HAVE_casesi
&& !HAVE_tablejump
))
2479 index
= expand_normal (index_expr
);
2481 /* If the index is a short or char that we do not have
2482 an insn to handle comparisons directly, convert it to
2483 a full integer now, rather than letting each comparison
2484 generate the conversion. */
2486 if (GET_MODE_CLASS (GET_MODE (index
)) == MODE_INT
2487 && ! have_insn_for (COMPARE
, GET_MODE (index
)))
2489 enum machine_mode wider_mode
;
2490 for (wider_mode
= GET_MODE (index
); wider_mode
!= VOIDmode
;
2491 wider_mode
= GET_MODE_WIDER_MODE (wider_mode
))
2492 if (have_insn_for (COMPARE
, wider_mode
))
2494 index
= convert_to_mode (wider_mode
, index
, unsignedp
);
2499 do_pending_stack_adjust ();
2502 index
= copy_to_reg (index
);
2504 /* We generate a binary decision tree to select the
2505 appropriate target code. This is done as follows:
2507 The list of cases is rearranged into a binary tree,
2508 nearly optimal assuming equal probability for each case.
2510 The tree is transformed into RTL, eliminating
2511 redundant test conditions at the same time.
2513 If program flow could reach the end of the
2514 decision tree an unconditional jump to the
2515 default code is emitted. */
2518 = (TREE_CODE (orig_type
) != ENUMERAL_TYPE
2519 && estimate_case_costs (case_list
));
2520 balance_case_nodes (&case_list
, NULL
);
2521 emit_case_nodes (index
, case_list
, default_label
, index_type
);
2522 emit_jump (default_label
);
2526 table_label
= gen_label_rtx ();
2527 if (! try_casesi (index_type
, index_expr
, minval
, range
,
2528 table_label
, default_label
))
2532 /* Index jumptables from zero for suitable values of
2533 minval to avoid a subtraction. */
2535 && compare_tree_int (minval
, 0) > 0
2536 && compare_tree_int (minval
, 3) < 0)
2538 minval
= build_int_cst (index_type
, 0);
2542 ok
= try_tablejump (index_type
, index_expr
, minval
, range
,
2543 table_label
, default_label
);
2547 /* Get table of labels to jump to, in order of case index. */
2549 ncases
= tree_low_cst (range
, 0) + 1;
2550 labelvec
= alloca (ncases
* sizeof (rtx
));
2551 memset (labelvec
, 0, ncases
* sizeof (rtx
));
2553 for (n
= case_list
; n
; n
= n
->right
)
2555 /* Compute the low and high bounds relative to the minimum
2556 value since that should fit in a HOST_WIDE_INT while the
2557 actual values may not. */
2559 = tree_low_cst (fold_build2 (MINUS_EXPR
, index_type
,
2560 n
->low
, minval
), 1);
2561 HOST_WIDE_INT i_high
2562 = tree_low_cst (fold_build2 (MINUS_EXPR
, index_type
,
2563 n
->high
, minval
), 1);
2566 for (i
= i_low
; i
<= i_high
; i
++)
2568 = gen_rtx_LABEL_REF (Pmode
, label_rtx (n
->code_label
));
2571 /* Fill in the gaps with the default. */
2572 for (i
= 0; i
< ncases
; i
++)
2573 if (labelvec
[i
] == 0)
2574 labelvec
[i
] = gen_rtx_LABEL_REF (Pmode
, default_label
);
2576 /* Output the table. */
2577 emit_label (table_label
);
2579 if (CASE_VECTOR_PC_RELATIVE
|| flag_pic
)
2580 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE
,
2581 gen_rtx_LABEL_REF (Pmode
, table_label
),
2582 gen_rtvec_v (ncases
, labelvec
),
2583 const0_rtx
, const0_rtx
));
2585 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE
,
2586 gen_rtvec_v (ncases
, labelvec
)));
2588 /* Record no drop-through after the table. */
2592 before_case
= NEXT_INSN (before_case
);
2593 end
= get_last_insn ();
2594 fail
= squeeze_notes (&before_case
, &end
);
2596 reorder_insns (before_case
, end
, start
);
2602 /* Generate code to jump to LABEL if OP0 and OP1 are equal in mode MODE. */
2605 do_jump_if_equal (enum machine_mode mode
, rtx op0
, rtx op1
, rtx label
,
2608 do_compare_rtx_and_jump (op0
, op1
, EQ
, unsignedp
, mode
,
2609 NULL_RTX
, NULL_RTX
, label
);
2612 /* Not all case values are encountered equally. This function
2613 uses a heuristic to weight case labels, in cases where that
2614 looks like a reasonable thing to do.
2616 Right now, all we try to guess is text, and we establish the
2619 chars above space: 16
2628 If we find any cases in the switch that are not either -1 or in the range
2629 of valid ASCII characters, or are control characters other than those
2630 commonly used with "\", don't treat this switch scanning text.
2632 Return 1 if these nodes are suitable for cost estimation, otherwise
2636 estimate_case_costs (case_node_ptr node
)
2638 tree min_ascii
= integer_minus_one_node
;
2639 tree max_ascii
= build_int_cst (TREE_TYPE (node
->high
), 127);
2643 /* If we haven't already made the cost table, make it now. Note that the
2644 lower bound of the table is -1, not zero. */
2646 if (! cost_table_initialized
)
2648 cost_table_initialized
= 1;
2650 for (i
= 0; i
< 128; i
++)
2653 COST_TABLE (i
) = 16;
2654 else if (ISPUNCT (i
))
2656 else if (ISCNTRL (i
))
2657 COST_TABLE (i
) = -1;
2660 COST_TABLE (' ') = 8;
2661 COST_TABLE ('\t') = 4;
2662 COST_TABLE ('\0') = 4;
2663 COST_TABLE ('\n') = 2;
2664 COST_TABLE ('\f') = 1;
2665 COST_TABLE ('\v') = 1;
2666 COST_TABLE ('\b') = 1;
2669 /* See if all the case expressions look like text. It is text if the
2670 constant is >= -1 and the highest constant is <= 127. Do all comparisons
2671 as signed arithmetic since we don't want to ever access cost_table with a
2672 value less than -1. Also check that none of the constants in a range
2673 are strange control characters. */
2675 for (n
= node
; n
; n
= n
->right
)
2677 if ((INT_CST_LT (n
->low
, min_ascii
)) || INT_CST_LT (max_ascii
, n
->high
))
2680 for (i
= (HOST_WIDE_INT
) TREE_INT_CST_LOW (n
->low
);
2681 i
<= (HOST_WIDE_INT
) TREE_INT_CST_LOW (n
->high
); i
++)
2682 if (COST_TABLE (i
) < 0)
2686 /* All interesting values are within the range of interesting
2687 ASCII characters. */
2691 /* Take an ordered list of case nodes
2692 and transform them into a near optimal binary tree,
2693 on the assumption that any target code selection value is as
2694 likely as any other.
2696 The transformation is performed by splitting the ordered
2697 list into two equal sections plus a pivot. The parts are
2698 then attached to the pivot as left and right branches. Each
2699 branch is then transformed recursively. */
2702 balance_case_nodes (case_node_ptr
*head
, case_node_ptr parent
)
2715 /* Count the number of entries on branch. Also count the ranges. */
2719 if (!tree_int_cst_equal (np
->low
, np
->high
))
2723 cost
+= COST_TABLE (TREE_INT_CST_LOW (np
->high
));
2727 cost
+= COST_TABLE (TREE_INT_CST_LOW (np
->low
));
2735 /* Split this list if it is long enough for that to help. */
2740 /* Find the place in the list that bisects the list's total cost,
2741 Here I gets half the total cost. */
2746 /* Skip nodes while their cost does not reach that amount. */
2747 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
2748 i
-= COST_TABLE (TREE_INT_CST_LOW ((*npp
)->high
));
2749 i
-= COST_TABLE (TREE_INT_CST_LOW ((*npp
)->low
));
2752 npp
= &(*npp
)->right
;
2757 /* Leave this branch lopsided, but optimize left-hand
2758 side and fill in `parent' fields for right-hand side. */
2760 np
->parent
= parent
;
2761 balance_case_nodes (&np
->left
, np
);
2762 for (; np
->right
; np
= np
->right
)
2763 np
->right
->parent
= np
;
2767 /* If there are just three nodes, split at the middle one. */
2769 npp
= &(*npp
)->right
;
2772 /* Find the place in the list that bisects the list's total cost,
2773 where ranges count as 2.
2774 Here I gets half the total cost. */
2775 i
= (i
+ ranges
+ 1) / 2;
2778 /* Skip nodes while their cost does not reach that amount. */
2779 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
2784 npp
= &(*npp
)->right
;
2789 np
->parent
= parent
;
2792 /* Optimize each of the two split parts. */
2793 balance_case_nodes (&np
->left
, np
);
2794 balance_case_nodes (&np
->right
, np
);
2798 /* Else leave this branch as one level,
2799 but fill in `parent' fields. */
2801 np
->parent
= parent
;
2802 for (; np
->right
; np
= np
->right
)
2803 np
->right
->parent
= np
;
2808 /* Search the parent sections of the case node tree
2809 to see if a test for the lower bound of NODE would be redundant.
2810 INDEX_TYPE is the type of the index expression.
2812 The instructions to generate the case decision tree are
2813 output in the same order as nodes are processed so it is
2814 known that if a parent node checks the range of the current
2815 node minus one that the current node is bounded at its lower
2816 span. Thus the test would be redundant. */
2819 node_has_low_bound (case_node_ptr node
, tree index_type
)
2822 case_node_ptr pnode
;
2824 /* If the lower bound of this node is the lowest value in the index type,
2825 we need not test it. */
2827 if (tree_int_cst_equal (node
->low
, TYPE_MIN_VALUE (index_type
)))
2830 /* If this node has a left branch, the value at the left must be less
2831 than that at this node, so it cannot be bounded at the bottom and
2832 we need not bother testing any further. */
2837 low_minus_one
= fold_build2 (MINUS_EXPR
, TREE_TYPE (node
->low
),
2839 build_int_cst (TREE_TYPE (node
->low
), 1));
2841 /* If the subtraction above overflowed, we can't verify anything.
2842 Otherwise, look for a parent that tests our value - 1. */
2844 if (! tree_int_cst_lt (low_minus_one
, node
->low
))
2847 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
2848 if (tree_int_cst_equal (low_minus_one
, pnode
->high
))
2854 /* Search the parent sections of the case node tree
2855 to see if a test for the upper bound of NODE would be redundant.
2856 INDEX_TYPE is the type of the index expression.
2858 The instructions to generate the case decision tree are
2859 output in the same order as nodes are processed so it is
2860 known that if a parent node checks the range of the current
2861 node plus one that the current node is bounded at its upper
2862 span. Thus the test would be redundant. */
2865 node_has_high_bound (case_node_ptr node
, tree index_type
)
2868 case_node_ptr pnode
;
2870 /* If there is no upper bound, obviously no test is needed. */
2872 if (TYPE_MAX_VALUE (index_type
) == NULL
)
2875 /* If the upper bound of this node is the highest value in the type
2876 of the index expression, we need not test against it. */
2878 if (tree_int_cst_equal (node
->high
, TYPE_MAX_VALUE (index_type
)))
2881 /* If this node has a right branch, the value at the right must be greater
2882 than that at this node, so it cannot be bounded at the top and
2883 we need not bother testing any further. */
2888 high_plus_one
= fold_build2 (PLUS_EXPR
, TREE_TYPE (node
->high
),
2890 build_int_cst (TREE_TYPE (node
->high
), 1));
2892 /* If the addition above overflowed, we can't verify anything.
2893 Otherwise, look for a parent that tests our value + 1. */
2895 if (! tree_int_cst_lt (node
->high
, high_plus_one
))
2898 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
2899 if (tree_int_cst_equal (high_plus_one
, pnode
->low
))
2905 /* Search the parent sections of the
2906 case node tree to see if both tests for the upper and lower
2907 bounds of NODE would be redundant. */
2910 node_is_bounded (case_node_ptr node
, tree index_type
)
2912 return (node_has_low_bound (node
, index_type
)
2913 && node_has_high_bound (node
, index_type
));
2916 /* Emit step-by-step code to select a case for the value of INDEX.
2917 The thus generated decision tree follows the form of the
2918 case-node binary tree NODE, whose nodes represent test conditions.
2919 INDEX_TYPE is the type of the index of the switch.
2921 Care is taken to prune redundant tests from the decision tree
2922 by detecting any boundary conditions already checked by
2923 emitted rtx. (See node_has_high_bound, node_has_low_bound
2924 and node_is_bounded, above.)
2926 Where the test conditions can be shown to be redundant we emit
2927 an unconditional jump to the target code. As a further
2928 optimization, the subordinates of a tree node are examined to
2929 check for bounded nodes. In this case conditional and/or
2930 unconditional jumps as a result of the boundary check for the
2931 current node are arranged to target the subordinates associated
2932 code for out of bound conditions on the current node.
2934 We can assume that when control reaches the code generated here,
2935 the index value has already been compared with the parents
2936 of this node, and determined to be on the same side of each parent
2937 as this node is. Thus, if this node tests for the value 51,
2938 and a parent tested for 52, we don't need to consider
2939 the possibility of a value greater than 51. If another parent
2940 tests for the value 50, then this node need not test anything. */
2943 emit_case_nodes (rtx index
, case_node_ptr node
, rtx default_label
,
2946 /* If INDEX has an unsigned type, we must make unsigned branches. */
2947 int unsignedp
= TYPE_UNSIGNED (index_type
);
2948 enum machine_mode mode
= GET_MODE (index
);
2949 enum machine_mode imode
= TYPE_MODE (index_type
);
2951 /* Handle indices detected as constant during RTL expansion. */
2952 if (mode
== VOIDmode
)
2955 /* See if our parents have already tested everything for us.
2956 If they have, emit an unconditional jump for this node. */
2957 if (node_is_bounded (node
, index_type
))
2958 emit_jump (label_rtx (node
->code_label
));
2960 else if (tree_int_cst_equal (node
->low
, node
->high
))
2962 /* Node is single valued. First see if the index expression matches
2963 this node and then check our children, if any. */
2965 do_jump_if_equal (mode
, index
,
2966 convert_modes (mode
, imode
,
2967 expand_normal (node
->low
),
2969 label_rtx (node
->code_label
), unsignedp
);
2971 if (node
->right
!= 0 && node
->left
!= 0)
2973 /* This node has children on both sides.
2974 Dispatch to one side or the other
2975 by comparing the index value with this node's value.
2976 If one subtree is bounded, check that one first,
2977 so we can avoid real branches in the tree. */
2979 if (node_is_bounded (node
->right
, index_type
))
2981 emit_cmp_and_jump_insns (index
,
2984 expand_normal (node
->high
),
2986 GT
, NULL_RTX
, mode
, unsignedp
,
2987 label_rtx (node
->right
->code_label
));
2988 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
2991 else if (node_is_bounded (node
->left
, index_type
))
2993 emit_cmp_and_jump_insns (index
,
2996 expand_normal (node
->high
),
2998 LT
, NULL_RTX
, mode
, unsignedp
,
2999 label_rtx (node
->left
->code_label
));
3000 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
3003 /* If both children are single-valued cases with no
3004 children, finish up all the work. This way, we can save
3005 one ordered comparison. */
3006 else if (tree_int_cst_equal (node
->right
->low
, node
->right
->high
)
3007 && node
->right
->left
== 0
3008 && node
->right
->right
== 0
3009 && tree_int_cst_equal (node
->left
->low
, node
->left
->high
)
3010 && node
->left
->left
== 0
3011 && node
->left
->right
== 0)
3013 /* Neither node is bounded. First distinguish the two sides;
3014 then emit the code for one side at a time. */
3016 /* See if the value matches what the right hand side
3018 do_jump_if_equal (mode
, index
,
3019 convert_modes (mode
, imode
,
3020 expand_normal (node
->right
->low
),
3022 label_rtx (node
->right
->code_label
),
3025 /* See if the value matches what the left hand side
3027 do_jump_if_equal (mode
, index
,
3028 convert_modes (mode
, imode
,
3029 expand_normal (node
->left
->low
),
3031 label_rtx (node
->left
->code_label
),
3037 /* Neither node is bounded. First distinguish the two sides;
3038 then emit the code for one side at a time. */
3040 tree test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
3042 /* See if the value is on the right. */
3043 emit_cmp_and_jump_insns (index
,
3046 expand_normal (node
->high
),
3048 GT
, NULL_RTX
, mode
, unsignedp
,
3049 label_rtx (test_label
));
3051 /* Value must be on the left.
3052 Handle the left-hand subtree. */
3053 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
3054 /* If left-hand subtree does nothing,
3056 emit_jump (default_label
);
3058 /* Code branches here for the right-hand subtree. */
3059 expand_label (test_label
);
3060 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
3064 else if (node
->right
!= 0 && node
->left
== 0)
3066 /* Here we have a right child but no left so we issue a conditional
3067 branch to default and process the right child.
3069 Omit the conditional branch to default if the right child
3070 does not have any children and is single valued; it would
3071 cost too much space to save so little time. */
3073 if (node
->right
->right
|| node
->right
->left
3074 || !tree_int_cst_equal (node
->right
->low
, node
->right
->high
))
3076 if (!node_has_low_bound (node
, index_type
))
3078 emit_cmp_and_jump_insns (index
,
3081 expand_normal (node
->high
),
3083 LT
, NULL_RTX
, mode
, unsignedp
,
3087 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
3090 /* We cannot process node->right normally
3091 since we haven't ruled out the numbers less than
3092 this node's value. So handle node->right explicitly. */
3093 do_jump_if_equal (mode
, index
,
3096 expand_normal (node
->right
->low
),
3098 label_rtx (node
->right
->code_label
), unsignedp
);
3101 else if (node
->right
== 0 && node
->left
!= 0)
3103 /* Just one subtree, on the left. */
3104 if (node
->left
->left
|| node
->left
->right
3105 || !tree_int_cst_equal (node
->left
->low
, node
->left
->high
))
3107 if (!node_has_high_bound (node
, index_type
))
3109 emit_cmp_and_jump_insns (index
,
3112 expand_normal (node
->high
),
3114 GT
, NULL_RTX
, mode
, unsignedp
,
3118 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
3121 /* We cannot process node->left normally
3122 since we haven't ruled out the numbers less than
3123 this node's value. So handle node->left explicitly. */
3124 do_jump_if_equal (mode
, index
,
3127 expand_normal (node
->left
->low
),
3129 label_rtx (node
->left
->code_label
), unsignedp
);
3134 /* Node is a range. These cases are very similar to those for a single
3135 value, except that we do not start by testing whether this node
3136 is the one to branch to. */
3138 if (node
->right
!= 0 && node
->left
!= 0)
3140 /* Node has subtrees on both sides.
3141 If the right-hand subtree is bounded,
3142 test for it first, since we can go straight there.
3143 Otherwise, we need to make a branch in the control structure,
3144 then handle the two subtrees. */
3145 tree test_label
= 0;
3147 if (node_is_bounded (node
->right
, index_type
))
3148 /* Right hand node is fully bounded so we can eliminate any
3149 testing and branch directly to the target code. */
3150 emit_cmp_and_jump_insns (index
,
3153 expand_normal (node
->high
),
3155 GT
, NULL_RTX
, mode
, unsignedp
,
3156 label_rtx (node
->right
->code_label
));
3159 /* Right hand node requires testing.
3160 Branch to a label where we will handle it later. */
3162 test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
3163 emit_cmp_and_jump_insns (index
,
3166 expand_normal (node
->high
),
3168 GT
, NULL_RTX
, mode
, unsignedp
,
3169 label_rtx (test_label
));
3172 /* Value belongs to this node or to the left-hand subtree. */
3174 emit_cmp_and_jump_insns (index
,
3177 expand_normal (node
->low
),
3179 GE
, NULL_RTX
, mode
, unsignedp
,
3180 label_rtx (node
->code_label
));
3182 /* Handle the left-hand subtree. */
3183 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
3185 /* If right node had to be handled later, do that now. */
3189 /* If the left-hand subtree fell through,
3190 don't let it fall into the right-hand subtree. */
3191 emit_jump (default_label
);
3193 expand_label (test_label
);
3194 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
3198 else if (node
->right
!= 0 && node
->left
== 0)
3200 /* Deal with values to the left of this node,
3201 if they are possible. */
3202 if (!node_has_low_bound (node
, index_type
))
3204 emit_cmp_and_jump_insns (index
,
3207 expand_normal (node
->low
),
3209 LT
, NULL_RTX
, mode
, unsignedp
,
3213 /* Value belongs to this node or to the right-hand subtree. */
3215 emit_cmp_and_jump_insns (index
,
3218 expand_normal (node
->high
),
3220 LE
, NULL_RTX
, mode
, unsignedp
,
3221 label_rtx (node
->code_label
));
3223 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
3226 else if (node
->right
== 0 && node
->left
!= 0)
3228 /* Deal with values to the right of this node,
3229 if they are possible. */
3230 if (!node_has_high_bound (node
, index_type
))
3232 emit_cmp_and_jump_insns (index
,
3235 expand_normal (node
->high
),
3237 GT
, NULL_RTX
, mode
, unsignedp
,
3241 /* Value belongs to this node or to the left-hand subtree. */
3243 emit_cmp_and_jump_insns (index
,
3246 expand_normal (node
->low
),
3248 GE
, NULL_RTX
, mode
, unsignedp
,
3249 label_rtx (node
->code_label
));
3251 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
3256 /* Node has no children so we check low and high bounds to remove
3257 redundant tests. Only one of the bounds can exist,
3258 since otherwise this node is bounded--a case tested already. */
3259 int high_bound
= node_has_high_bound (node
, index_type
);
3260 int low_bound
= node_has_low_bound (node
, index_type
);
3262 if (!high_bound
&& low_bound
)
3264 emit_cmp_and_jump_insns (index
,
3267 expand_normal (node
->high
),
3269 GT
, NULL_RTX
, mode
, unsignedp
,
3273 else if (!low_bound
&& high_bound
)
3275 emit_cmp_and_jump_insns (index
,
3278 expand_normal (node
->low
),
3280 LT
, NULL_RTX
, mode
, unsignedp
,
3283 else if (!low_bound
&& !high_bound
)
3285 /* Widen LOW and HIGH to the same width as INDEX. */
3286 tree type
= lang_hooks
.types
.type_for_mode (mode
, unsignedp
);
3287 tree low
= build1 (CONVERT_EXPR
, type
, node
->low
);
3288 tree high
= build1 (CONVERT_EXPR
, type
, node
->high
);
3289 rtx low_rtx
, new_index
, new_bound
;
3291 /* Instead of doing two branches, emit one unsigned branch for
3292 (index-low) > (high-low). */
3293 low_rtx
= expand_expr (low
, NULL_RTX
, mode
, EXPAND_NORMAL
);
3294 new_index
= expand_simple_binop (mode
, MINUS
, index
, low_rtx
,
3295 NULL_RTX
, unsignedp
,
3297 new_bound
= expand_expr (fold_build2 (MINUS_EXPR
, type
,
3299 NULL_RTX
, mode
, EXPAND_NORMAL
);
3301 emit_cmp_and_jump_insns (new_index
, new_bound
, GT
, NULL_RTX
,
3302 mode
, 1, default_label
);
3305 emit_jump (label_rtx (node
->code_label
));