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, 2008, 2009,
4 2010, 2011, 2012 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 3, 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 COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* This file handles the generation of rtl code from tree structure
23 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
24 The functions whose names start with `expand_' are called by the
25 expander to generate RTL instructions for various kinds of constructs. */
29 #include "coretypes.h"
33 #include "hard-reg-set.h"
39 #include "insn-config.h"
44 #include "diagnostic-core.h"
47 #include "langhooks.h"
53 #include "alloc-pool.h"
54 #include "pretty-print.h"
59 /* Functions and data structures for expanding case statements. */
61 /* Case label structure, used to hold info on labels within case
62 statements. We handle "range" labels; for a single-value label
63 as in C, the high and low limits are the same.
65 We start with a vector of case nodes sorted in ascending order, and
66 the default label as the last element in the vector. Before expanding
67 to RTL, we transform this vector into a list linked via the RIGHT
68 fields in the case_node struct. Nodes with higher case values are
71 Switch statements can be output in three forms. A branch table is
72 used if there are more than a few labels and the labels are dense
73 within the range between the smallest and largest case value. If a
74 branch table is used, no further manipulations are done with the case
77 The alternative to the use of a branch table is to generate a series
78 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
79 and PARENT fields to hold a binary tree. Initially the tree is
80 totally unbalanced, with everything on the right. We balance the tree
81 with nodes on the left having lower case values than the parent
82 and nodes on the right having higher values. We then output the tree
85 For very small, suitable switch statements, we can generate a series
86 of simple bit test and branches instead. */
90 struct case_node
*left
; /* Left son in binary tree */
91 struct case_node
*right
; /* Right son in binary tree; also node chain */
92 struct case_node
*parent
; /* Parent of node in binary tree */
93 tree low
; /* Lowest index value for this label */
94 tree high
; /* Highest index value for this label */
95 tree code_label
; /* Label to jump to when node matches */
98 typedef struct case_node case_node
;
99 typedef struct case_node
*case_node_ptr
;
102 static int n_occurrences (int, const char *);
103 static bool tree_conflicts_with_clobbers_p (tree
, HARD_REG_SET
*);
104 static void expand_nl_goto_receiver (void);
105 static bool check_operand_nalternatives (tree
, tree
);
106 static bool check_unique_operand_names (tree
, tree
, tree
);
107 static char *resolve_operand_name_1 (char *, tree
, tree
, tree
);
108 static void expand_null_return_1 (void);
109 static void expand_value_return (rtx
);
110 static void balance_case_nodes (case_node_ptr
*, case_node_ptr
);
111 static int node_has_low_bound (case_node_ptr
, tree
);
112 static int node_has_high_bound (case_node_ptr
, tree
);
113 static int node_is_bounded (case_node_ptr
, tree
);
114 static void emit_case_nodes (rtx
, case_node_ptr
, rtx
, tree
);
115 static struct case_node
*add_case_node (struct case_node
*, tree
,
116 tree
, tree
, tree
, alloc_pool
);
119 /* Return the rtx-label that corresponds to a LABEL_DECL,
120 creating it if necessary. */
123 label_rtx (tree label
)
125 gcc_assert (TREE_CODE (label
) == LABEL_DECL
);
127 if (!DECL_RTL_SET_P (label
))
129 rtx r
= gen_label_rtx ();
130 SET_DECL_RTL (label
, r
);
131 if (FORCED_LABEL (label
) || DECL_NONLOCAL (label
))
132 LABEL_PRESERVE_P (r
) = 1;
135 return DECL_RTL (label
);
138 /* As above, but also put it on the forced-reference list of the
139 function that contains it. */
141 force_label_rtx (tree label
)
143 rtx ref
= label_rtx (label
);
144 tree function
= decl_function_context (label
);
146 gcc_assert (function
);
148 forced_labels
= gen_rtx_EXPR_LIST (VOIDmode
, ref
, forced_labels
);
152 /* Add an unconditional jump to LABEL as the next sequential instruction. */
155 emit_jump (rtx label
)
157 do_pending_stack_adjust ();
158 emit_jump_insn (gen_jump (label
));
162 /* Emit code to jump to the address
163 specified by the pointer expression EXP. */
166 expand_computed_goto (tree exp
)
168 rtx x
= expand_normal (exp
);
170 x
= convert_memory_address (Pmode
, x
);
172 do_pending_stack_adjust ();
173 emit_indirect_jump (x
);
176 /* Handle goto statements and the labels that they can go to. */
178 /* Specify the location in the RTL code of a label LABEL,
179 which is a LABEL_DECL tree node.
181 This is used for the kind of label that the user can jump to with a
182 goto statement, and for alternatives of a switch or case statement.
183 RTL labels generated for loops and conditionals don't go through here;
184 they are generated directly at the RTL level, by other functions below.
186 Note that this has nothing to do with defining label *names*.
187 Languages vary in how they do that and what that even means. */
190 expand_label (tree label
)
192 rtx label_r
= label_rtx (label
);
194 do_pending_stack_adjust ();
195 emit_label (label_r
);
196 if (DECL_NAME (label
))
197 LABEL_NAME (DECL_RTL (label
)) = IDENTIFIER_POINTER (DECL_NAME (label
));
199 if (DECL_NONLOCAL (label
))
201 expand_nl_goto_receiver ();
202 nonlocal_goto_handler_labels
203 = gen_rtx_EXPR_LIST (VOIDmode
, label_r
,
204 nonlocal_goto_handler_labels
);
207 if (FORCED_LABEL (label
))
208 forced_labels
= gen_rtx_EXPR_LIST (VOIDmode
, label_r
, forced_labels
);
210 if (DECL_NONLOCAL (label
) || FORCED_LABEL (label
))
211 maybe_set_first_label_num (label_r
);
214 /* Generate RTL code for a `goto' statement with target label LABEL.
215 LABEL should be a LABEL_DECL tree node that was or will later be
216 defined with `expand_label'. */
219 expand_goto (tree label
)
221 #ifdef ENABLE_CHECKING
222 /* Check for a nonlocal goto to a containing function. Should have
223 gotten translated to __builtin_nonlocal_goto. */
224 tree context
= decl_function_context (label
);
225 gcc_assert (!context
|| context
== current_function_decl
);
228 emit_jump (label_rtx (label
));
231 /* Return the number of times character C occurs in string S. */
233 n_occurrences (int c
, const char *s
)
241 /* Generate RTL for an asm statement (explicit assembler code).
242 STRING is a STRING_CST node containing the assembler code text,
243 or an ADDR_EXPR containing a STRING_CST. VOL nonzero means the
244 insn is volatile; don't optimize it. */
247 expand_asm_loc (tree string
, int vol
, location_t locus
)
251 if (TREE_CODE (string
) == ADDR_EXPR
)
252 string
= TREE_OPERAND (string
, 0);
254 body
= gen_rtx_ASM_INPUT_loc (VOIDmode
,
255 ggc_strdup (TREE_STRING_POINTER (string
)),
258 MEM_VOLATILE_P (body
) = vol
;
263 /* Parse the output constraint pointed to by *CONSTRAINT_P. It is the
264 OPERAND_NUMth output operand, indexed from zero. There are NINPUTS
265 inputs and NOUTPUTS outputs to this extended-asm. Upon return,
266 *ALLOWS_MEM will be TRUE iff the constraint allows the use of a
267 memory operand. Similarly, *ALLOWS_REG will be TRUE iff the
268 constraint allows the use of a register operand. And, *IS_INOUT
269 will be true if the operand is read-write, i.e., if it is used as
270 an input as well as an output. If *CONSTRAINT_P is not in
271 canonical form, it will be made canonical. (Note that `+' will be
272 replaced with `=' as part of this process.)
274 Returns TRUE if all went well; FALSE if an error occurred. */
277 parse_output_constraint (const char **constraint_p
, int operand_num
,
278 int ninputs
, int noutputs
, bool *allows_mem
,
279 bool *allows_reg
, bool *is_inout
)
281 const char *constraint
= *constraint_p
;
284 /* Assume the constraint doesn't allow the use of either a register
289 /* Allow the `=' or `+' to not be at the beginning of the string,
290 since it wasn't explicitly documented that way, and there is a
291 large body of code that puts it last. Swap the character to
292 the front, so as not to uglify any place else. */
293 p
= strchr (constraint
, '=');
295 p
= strchr (constraint
, '+');
297 /* If the string doesn't contain an `=', issue an error
301 error ("output operand constraint lacks %<=%>");
305 /* If the constraint begins with `+', then the operand is both read
306 from and written to. */
307 *is_inout
= (*p
== '+');
309 /* Canonicalize the output constraint so that it begins with `='. */
310 if (p
!= constraint
|| *is_inout
)
313 size_t c_len
= strlen (constraint
);
316 warning (0, "output constraint %qc for operand %d "
317 "is not at the beginning",
320 /* Make a copy of the constraint. */
321 buf
= XALLOCAVEC (char, c_len
+ 1);
322 strcpy (buf
, constraint
);
323 /* Swap the first character and the `=' or `+'. */
324 buf
[p
- constraint
] = buf
[0];
325 /* Make sure the first character is an `='. (Until we do this,
326 it might be a `+'.) */
328 /* Replace the constraint with the canonicalized string. */
329 *constraint_p
= ggc_alloc_string (buf
, c_len
);
330 constraint
= *constraint_p
;
333 /* Loop through the constraint string. */
334 for (p
= constraint
+ 1; *p
; p
+= CONSTRAINT_LEN (*p
, p
))
339 error ("operand constraint contains incorrectly positioned "
344 if (operand_num
+ 1 == ninputs
+ noutputs
)
346 error ("%<%%%> constraint used with last operand");
351 case 'V': case TARGET_MEM_CONSTRAINT
: case 'o':
355 case '?': case '!': case '*': case '&': case '#':
356 case 'E': case 'F': case 'G': case 'H':
357 case 's': case 'i': case 'n':
358 case 'I': case 'J': case 'K': case 'L': case 'M':
359 case 'N': case 'O': case 'P': case ',':
362 case '0': case '1': case '2': case '3': case '4':
363 case '5': case '6': case '7': case '8': case '9':
365 error ("matching constraint not valid in output operand");
369 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
370 excepting those that expand_call created. So match memory
387 if (REG_CLASS_FROM_CONSTRAINT (*p
, p
) != NO_REGS
)
389 #ifdef EXTRA_CONSTRAINT_STR
390 else if (EXTRA_ADDRESS_CONSTRAINT (*p
, p
))
392 else if (EXTRA_MEMORY_CONSTRAINT (*p
, p
))
396 /* Otherwise we can't assume anything about the nature of
397 the constraint except that it isn't purely registers.
398 Treat it like "g" and hope for the best. */
409 /* Similar, but for input constraints. */
412 parse_input_constraint (const char **constraint_p
, int input_num
,
413 int ninputs
, int noutputs
, int ninout
,
414 const char * const * constraints
,
415 bool *allows_mem
, bool *allows_reg
)
417 const char *constraint
= *constraint_p
;
418 const char *orig_constraint
= constraint
;
419 size_t c_len
= strlen (constraint
);
421 bool saw_match
= false;
423 /* Assume the constraint doesn't allow the use of either
424 a register or memory. */
428 /* Make sure constraint has neither `=', `+', nor '&'. */
430 for (j
= 0; j
< c_len
; j
+= CONSTRAINT_LEN (constraint
[j
], constraint
+j
))
431 switch (constraint
[j
])
433 case '+': case '=': case '&':
434 if (constraint
== orig_constraint
)
436 error ("input operand constraint contains %qc", constraint
[j
]);
442 if (constraint
== orig_constraint
443 && input_num
+ 1 == ninputs
- ninout
)
445 error ("%<%%%> constraint used with last operand");
450 case 'V': case TARGET_MEM_CONSTRAINT
: case 'o':
455 case '?': case '!': case '*': case '#':
456 case 'E': case 'F': case 'G': case 'H':
457 case 's': case 'i': case 'n':
458 case 'I': case 'J': case 'K': case 'L': case 'M':
459 case 'N': case 'O': case 'P': case ',':
462 /* Whether or not a numeric constraint allows a register is
463 decided by the matching constraint, and so there is no need
464 to do anything special with them. We must handle them in
465 the default case, so that we don't unnecessarily force
466 operands to memory. */
467 case '0': case '1': case '2': case '3': case '4':
468 case '5': case '6': case '7': case '8': case '9':
475 match
= strtoul (constraint
+ j
, &end
, 10);
476 if (match
>= (unsigned long) noutputs
)
478 error ("matching constraint references invalid operand number");
482 /* Try and find the real constraint for this dup. Only do this
483 if the matching constraint is the only alternative. */
485 && (j
== 0 || (j
== 1 && constraint
[0] == '%')))
487 constraint
= constraints
[match
];
488 *constraint_p
= constraint
;
489 c_len
= strlen (constraint
);
491 /* ??? At the end of the loop, we will skip the first part of
492 the matched constraint. This assumes not only that the
493 other constraint is an output constraint, but also that
494 the '=' or '+' come first. */
498 j
= end
- constraint
;
499 /* Anticipate increment at end of loop. */
514 if (! ISALPHA (constraint
[j
]))
516 error ("invalid punctuation %qc in constraint", constraint
[j
]);
519 if (REG_CLASS_FROM_CONSTRAINT (constraint
[j
], constraint
+ j
)
522 #ifdef EXTRA_CONSTRAINT_STR
523 else if (EXTRA_ADDRESS_CONSTRAINT (constraint
[j
], constraint
+ j
))
525 else if (EXTRA_MEMORY_CONSTRAINT (constraint
[j
], constraint
+ j
))
529 /* Otherwise we can't assume anything about the nature of
530 the constraint except that it isn't purely registers.
531 Treat it like "g" and hope for the best. */
539 if (saw_match
&& !*allows_reg
)
540 warning (0, "matching constraint does not allow a register");
545 /* Return DECL iff there's an overlap between *REGS and DECL, where DECL
546 can be an asm-declared register. Called via walk_tree. */
549 decl_overlaps_hard_reg_set_p (tree
*declp
, int *walk_subtrees ATTRIBUTE_UNUSED
,
553 const HARD_REG_SET
*const regs
= (const HARD_REG_SET
*) data
;
555 if (TREE_CODE (decl
) == VAR_DECL
)
557 if (DECL_HARD_REGISTER (decl
)
558 && REG_P (DECL_RTL (decl
))
559 && REGNO (DECL_RTL (decl
)) < FIRST_PSEUDO_REGISTER
)
561 rtx reg
= DECL_RTL (decl
);
563 if (overlaps_hard_reg_set_p (*regs
, GET_MODE (reg
), REGNO (reg
)))
568 else if (TYPE_P (decl
) || TREE_CODE (decl
) == PARM_DECL
)
573 /* If there is an overlap between *REGS and DECL, return the first overlap
576 tree_overlaps_hard_reg_set (tree decl
, HARD_REG_SET
*regs
)
578 return walk_tree (&decl
, decl_overlaps_hard_reg_set_p
, regs
, NULL
);
581 /* Check for overlap between registers marked in CLOBBERED_REGS and
582 anything inappropriate in T. Emit error and return the register
583 variable definition for error, NULL_TREE for ok. */
586 tree_conflicts_with_clobbers_p (tree t
, HARD_REG_SET
*clobbered_regs
)
588 /* Conflicts between asm-declared register variables and the clobber
589 list are not allowed. */
590 tree overlap
= tree_overlaps_hard_reg_set (t
, clobbered_regs
);
594 error ("asm-specifier for variable %qE conflicts with asm clobber list",
595 DECL_NAME (overlap
));
597 /* Reset registerness to stop multiple errors emitted for a single
599 DECL_REGISTER (overlap
) = 0;
606 /* Generate RTL for an asm statement with arguments.
607 STRING is the instruction template.
608 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
609 Each output or input has an expression in the TREE_VALUE and
610 a tree list in TREE_PURPOSE which in turn contains a constraint
611 name in TREE_VALUE (or NULL_TREE) and a constraint string
613 CLOBBERS is a list of STRING_CST nodes each naming a hard register
614 that is clobbered by this insn.
616 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
617 Some elements of OUTPUTS may be replaced with trees representing temporary
618 values. The caller should copy those temporary values to the originally
621 VOL nonzero means the insn is volatile; don't optimize it. */
624 expand_asm_operands (tree string
, tree outputs
, tree inputs
,
625 tree clobbers
, tree labels
, int vol
, location_t locus
)
627 rtvec argvec
, constraintvec
, labelvec
;
629 int ninputs
= list_length (inputs
);
630 int noutputs
= list_length (outputs
);
631 int nlabels
= list_length (labels
);
634 HARD_REG_SET clobbered_regs
;
635 int clobber_conflict_found
= 0;
639 /* Vector of RTX's of evaluated output operands. */
640 rtx
*output_rtx
= XALLOCAVEC (rtx
, noutputs
);
641 int *inout_opnum
= XALLOCAVEC (int, noutputs
);
642 rtx
*real_output_rtx
= XALLOCAVEC (rtx
, noutputs
);
643 enum machine_mode
*inout_mode
= XALLOCAVEC (enum machine_mode
, noutputs
);
644 const char **constraints
= XALLOCAVEC (const char *, noutputs
+ ninputs
);
645 int old_generating_concat_p
= generating_concat_p
;
647 /* An ASM with no outputs needs to be treated as volatile, for now. */
651 if (! check_operand_nalternatives (outputs
, inputs
))
654 string
= resolve_asm_operand_names (string
, outputs
, inputs
, labels
);
656 /* Collect constraints. */
658 for (t
= outputs
; t
; t
= TREE_CHAIN (t
), i
++)
659 constraints
[i
] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t
)));
660 for (t
= inputs
; t
; t
= TREE_CHAIN (t
), i
++)
661 constraints
[i
] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t
)));
663 /* Sometimes we wish to automatically clobber registers across an asm.
664 Case in point is when the i386 backend moved from cc0 to a hard reg --
665 maintaining source-level compatibility means automatically clobbering
666 the flags register. */
667 clobbers
= targetm
.md_asm_clobbers (outputs
, inputs
, clobbers
);
669 /* Count the number of meaningful clobbered registers, ignoring what
670 we would ignore later. */
672 CLEAR_HARD_REG_SET (clobbered_regs
);
673 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
678 if (TREE_VALUE (tail
) == error_mark_node
)
680 regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
682 i
= decode_reg_name_and_count (regname
, &nregs
);
686 error ("unknown register name %qs in %<asm%>", regname
);
688 /* Mark clobbered registers. */
693 for (reg
= i
; reg
< i
+ nregs
; reg
++)
697 /* Clobbering the PIC register is an error. */
698 if (reg
== (int) PIC_OFFSET_TABLE_REGNUM
)
700 error ("PIC register clobbered by %qs in %<asm%>", regname
);
704 SET_HARD_REG_BIT (clobbered_regs
, reg
);
709 /* First pass over inputs and outputs checks validity and sets
710 mark_addressable if needed. */
713 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
715 tree val
= TREE_VALUE (tail
);
716 tree type
= TREE_TYPE (val
);
717 const char *constraint
;
722 /* If there's an erroneous arg, emit no insn. */
723 if (type
== error_mark_node
)
726 /* Try to parse the output constraint. If that fails, there's
727 no point in going further. */
728 constraint
= constraints
[i
];
729 if (!parse_output_constraint (&constraint
, i
, ninputs
, noutputs
,
730 &allows_mem
, &allows_reg
, &is_inout
))
737 && REG_P (DECL_RTL (val
))
738 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
))))
739 mark_addressable (val
);
746 if (ninputs
+ noutputs
> MAX_RECOG_OPERANDS
)
748 error ("more than %d operands in %<asm%>", MAX_RECOG_OPERANDS
);
752 for (i
= 0, tail
= inputs
; tail
; i
++, tail
= TREE_CHAIN (tail
))
754 bool allows_reg
, allows_mem
;
755 const char *constraint
;
757 /* If there's an erroneous arg, emit no insn, because the ASM_INPUT
758 would get VOIDmode and that could cause a crash in reload. */
759 if (TREE_TYPE (TREE_VALUE (tail
)) == error_mark_node
)
762 constraint
= constraints
[i
+ noutputs
];
763 if (! parse_input_constraint (&constraint
, i
, ninputs
, noutputs
, ninout
,
764 constraints
, &allows_mem
, &allows_reg
))
767 if (! allows_reg
&& allows_mem
)
768 mark_addressable (TREE_VALUE (tail
));
771 /* Second pass evaluates arguments. */
773 /* Make sure stack is consistent for asm goto. */
775 do_pending_stack_adjust ();
778 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
780 tree val
= TREE_VALUE (tail
);
781 tree type
= TREE_TYPE (val
);
788 ok
= parse_output_constraint (&constraints
[i
], i
, ninputs
,
789 noutputs
, &allows_mem
, &allows_reg
,
793 /* If an output operand is not a decl or indirect ref and our constraint
794 allows a register, make a temporary to act as an intermediate.
795 Make the asm insn write into that, then our caller will copy it to
796 the real output operand. Likewise for promoted variables. */
798 generating_concat_p
= 0;
800 real_output_rtx
[i
] = NULL_RTX
;
801 if ((TREE_CODE (val
) == INDIRECT_REF
804 && (allows_mem
|| REG_P (DECL_RTL (val
)))
805 && ! (REG_P (DECL_RTL (val
))
806 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
)))
810 op
= expand_expr (val
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
812 op
= validize_mem (op
);
814 if (! allows_reg
&& !MEM_P (op
))
815 error ("output number %d not directly addressable", i
);
816 if ((! allows_mem
&& MEM_P (op
))
817 || GET_CODE (op
) == CONCAT
)
819 real_output_rtx
[i
] = op
;
820 op
= gen_reg_rtx (GET_MODE (op
));
822 emit_move_insn (op
, real_output_rtx
[i
]);
827 op
= assign_temp (type
, 0, 1);
828 op
= validize_mem (op
);
829 if (!MEM_P (op
) && TREE_CODE (TREE_VALUE (tail
)) == SSA_NAME
)
830 set_reg_attrs_for_decl_rtl (SSA_NAME_VAR (TREE_VALUE (tail
)), op
);
831 TREE_VALUE (tail
) = make_tree (type
, op
);
835 generating_concat_p
= old_generating_concat_p
;
839 inout_mode
[ninout
] = TYPE_MODE (type
);
840 inout_opnum
[ninout
++] = i
;
843 if (tree_conflicts_with_clobbers_p (val
, &clobbered_regs
))
844 clobber_conflict_found
= 1;
847 /* Make vectors for the expression-rtx, constraint strings,
848 and named operands. */
850 argvec
= rtvec_alloc (ninputs
);
851 constraintvec
= rtvec_alloc (ninputs
);
852 labelvec
= rtvec_alloc (nlabels
);
854 body
= gen_rtx_ASM_OPERANDS ((noutputs
== 0 ? VOIDmode
855 : GET_MODE (output_rtx
[0])),
856 ggc_strdup (TREE_STRING_POINTER (string
)),
857 empty_string
, 0, argvec
, constraintvec
,
860 MEM_VOLATILE_P (body
) = vol
;
862 /* Eval the inputs and put them into ARGVEC.
863 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
865 for (i
= 0, tail
= inputs
; tail
; tail
= TREE_CHAIN (tail
), ++i
)
867 bool allows_reg
, allows_mem
;
868 const char *constraint
;
873 constraint
= constraints
[i
+ noutputs
];
874 ok
= parse_input_constraint (&constraint
, i
, ninputs
, noutputs
, ninout
,
875 constraints
, &allows_mem
, &allows_reg
);
878 generating_concat_p
= 0;
880 val
= TREE_VALUE (tail
);
881 type
= TREE_TYPE (val
);
882 /* EXPAND_INITIALIZER will not generate code for valid initializer
883 constants, but will still generate code for other types of operand.
884 This is the behavior we want for constant constraints. */
885 op
= expand_expr (val
, NULL_RTX
, VOIDmode
,
886 allows_reg
? EXPAND_NORMAL
887 : allows_mem
? EXPAND_MEMORY
888 : EXPAND_INITIALIZER
);
890 /* Never pass a CONCAT to an ASM. */
891 if (GET_CODE (op
) == CONCAT
)
892 op
= force_reg (GET_MODE (op
), op
);
894 op
= validize_mem (op
);
896 if (asm_operand_ok (op
, constraint
, NULL
) <= 0)
898 if (allows_reg
&& TYPE_MODE (type
) != BLKmode
)
899 op
= force_reg (TYPE_MODE (type
), op
);
900 else if (!allows_mem
)
901 warning (0, "asm operand %d probably doesn%'t match constraints",
905 /* We won't recognize either volatile memory or memory
906 with a queued address as available a memory_operand
907 at this point. Ignore it: clearly this *is* a memory. */
913 generating_concat_p
= old_generating_concat_p
;
914 ASM_OPERANDS_INPUT (body
, i
) = op
;
916 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body
, i
)
917 = gen_rtx_ASM_INPUT (TYPE_MODE (type
),
918 ggc_strdup (constraints
[i
+ noutputs
]));
920 if (tree_conflicts_with_clobbers_p (val
, &clobbered_regs
))
921 clobber_conflict_found
= 1;
924 /* Protect all the operands from the queue now that they have all been
927 generating_concat_p
= 0;
929 /* For in-out operands, copy output rtx to input rtx. */
930 for (i
= 0; i
< ninout
; i
++)
932 int j
= inout_opnum
[i
];
935 ASM_OPERANDS_INPUT (body
, ninputs
- ninout
+ i
)
938 sprintf (buffer
, "%d", j
);
939 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body
, ninputs
- ninout
+ i
)
940 = gen_rtx_ASM_INPUT (inout_mode
[i
], ggc_strdup (buffer
));
943 /* Copy labels to the vector. */
944 for (i
= 0, tail
= labels
; i
< nlabels
; ++i
, tail
= TREE_CHAIN (tail
))
945 ASM_OPERANDS_LABEL (body
, i
)
946 = gen_rtx_LABEL_REF (Pmode
, label_rtx (TREE_VALUE (tail
)));
948 generating_concat_p
= old_generating_concat_p
;
950 /* Now, for each output, construct an rtx
951 (set OUTPUT (asm_operands INSN OUTPUTCONSTRAINT OUTPUTNUMBER
952 ARGVEC CONSTRAINTS OPNAMES))
953 If there is more than one, put them inside a PARALLEL. */
955 if (nlabels
> 0 && nclobbers
== 0)
957 gcc_assert (noutputs
== 0);
958 emit_jump_insn (body
);
960 else if (noutputs
== 0 && nclobbers
== 0)
962 /* No output operands: put in a raw ASM_OPERANDS rtx. */
965 else if (noutputs
== 1 && nclobbers
== 0)
967 ASM_OPERANDS_OUTPUT_CONSTRAINT (body
) = ggc_strdup (constraints
[0]);
968 emit_insn (gen_rtx_SET (VOIDmode
, output_rtx
[0], body
));
978 body
= gen_rtx_PARALLEL (VOIDmode
, rtvec_alloc (num
+ nclobbers
));
980 /* For each output operand, store a SET. */
981 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
984 = gen_rtx_SET (VOIDmode
,
987 (GET_MODE (output_rtx
[i
]),
988 ggc_strdup (TREE_STRING_POINTER (string
)),
989 ggc_strdup (constraints
[i
]),
990 i
, argvec
, constraintvec
, labelvec
, locus
));
992 MEM_VOLATILE_P (SET_SRC (XVECEXP (body
, 0, i
))) = vol
;
995 /* If there are no outputs (but there are some clobbers)
996 store the bare ASM_OPERANDS into the PARALLEL. */
999 XVECEXP (body
, 0, i
++) = obody
;
1001 /* Store (clobber REG) for each clobbered register specified. */
1003 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1005 const char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1007 int j
= decode_reg_name_and_count (regname
, &nregs
);
1012 if (j
== -3) /* `cc', which is not a register */
1015 if (j
== -4) /* `memory', don't cache memory across asm */
1017 XVECEXP (body
, 0, i
++)
1018 = gen_rtx_CLOBBER (VOIDmode
,
1021 gen_rtx_SCRATCH (VOIDmode
)));
1025 /* Ignore unknown register, error already signaled. */
1029 for (reg
= j
; reg
< j
+ nregs
; reg
++)
1031 /* Use QImode since that's guaranteed to clobber just
1033 clobbered_reg
= gen_rtx_REG (QImode
, reg
);
1035 /* Do sanity check for overlap between clobbers and
1036 respectively input and outputs that hasn't been
1037 handled. Such overlap should have been detected and
1039 if (!clobber_conflict_found
)
1043 /* We test the old body (obody) contents to avoid
1044 tripping over the under-construction body. */
1045 for (opno
= 0; opno
< noutputs
; opno
++)
1046 if (reg_overlap_mentioned_p (clobbered_reg
,
1049 ("asm clobber conflict with output operand");
1051 for (opno
= 0; opno
< ninputs
- ninout
; opno
++)
1052 if (reg_overlap_mentioned_p (clobbered_reg
,
1053 ASM_OPERANDS_INPUT (obody
,
1056 ("asm clobber conflict with input operand");
1059 XVECEXP (body
, 0, i
++)
1060 = gen_rtx_CLOBBER (VOIDmode
, clobbered_reg
);
1065 emit_jump_insn (body
);
1070 /* For any outputs that needed reloading into registers, spill them
1071 back to where they belong. */
1072 for (i
= 0; i
< noutputs
; ++i
)
1073 if (real_output_rtx
[i
])
1074 emit_move_insn (real_output_rtx
[i
], output_rtx
[i
]);
1076 crtl
->has_asm_statement
= 1;
1081 expand_asm_stmt (gimple stmt
)
1084 tree outputs
, tail
, t
;
1088 tree str
, out
, in
, cl
, labels
;
1089 location_t locus
= gimple_location (stmt
);
1091 /* Meh... convert the gimple asm operands into real tree lists.
1092 Eventually we should make all routines work on the vectors instead
1093 of relying on TREE_CHAIN. */
1095 n
= gimple_asm_noutputs (stmt
);
1098 t
= out
= gimple_asm_output_op (stmt
, 0);
1099 for (i
= 1; i
< n
; i
++)
1100 t
= TREE_CHAIN (t
) = gimple_asm_output_op (stmt
, i
);
1104 n
= gimple_asm_ninputs (stmt
);
1107 t
= in
= gimple_asm_input_op (stmt
, 0);
1108 for (i
= 1; i
< n
; i
++)
1109 t
= TREE_CHAIN (t
) = gimple_asm_input_op (stmt
, i
);
1113 n
= gimple_asm_nclobbers (stmt
);
1116 t
= cl
= gimple_asm_clobber_op (stmt
, 0);
1117 for (i
= 1; i
< n
; i
++)
1118 t
= TREE_CHAIN (t
) = gimple_asm_clobber_op (stmt
, i
);
1122 n
= gimple_asm_nlabels (stmt
);
1125 t
= labels
= gimple_asm_label_op (stmt
, 0);
1126 for (i
= 1; i
< n
; i
++)
1127 t
= TREE_CHAIN (t
) = gimple_asm_label_op (stmt
, i
);
1130 s
= gimple_asm_string (stmt
);
1131 str
= build_string (strlen (s
), s
);
1133 if (gimple_asm_input_p (stmt
))
1135 expand_asm_loc (str
, gimple_asm_volatile_p (stmt
), locus
);
1140 noutputs
= gimple_asm_noutputs (stmt
);
1141 /* o[I] is the place that output number I should be written. */
1142 o
= (tree
*) alloca (noutputs
* sizeof (tree
));
1144 /* Record the contents of OUTPUTS before it is modified. */
1145 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1146 o
[i
] = TREE_VALUE (tail
);
1148 /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
1149 OUTPUTS some trees for where the values were actually stored. */
1150 expand_asm_operands (str
, outputs
, in
, cl
, labels
,
1151 gimple_asm_volatile_p (stmt
), locus
);
1153 /* Copy all the intermediate outputs into the specified outputs. */
1154 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1156 if (o
[i
] != TREE_VALUE (tail
))
1158 expand_assignment (o
[i
], TREE_VALUE (tail
), false);
1161 /* Restore the original value so that it's correct the next
1162 time we expand this function. */
1163 TREE_VALUE (tail
) = o
[i
];
1168 /* A subroutine of expand_asm_operands. Check that all operands have
1169 the same number of alternatives. Return true if so. */
1172 check_operand_nalternatives (tree outputs
, tree inputs
)
1174 if (outputs
|| inputs
)
1176 tree tmp
= TREE_PURPOSE (outputs
? outputs
: inputs
);
1178 = n_occurrences (',', TREE_STRING_POINTER (TREE_VALUE (tmp
)));
1181 if (nalternatives
+ 1 > MAX_RECOG_ALTERNATIVES
)
1183 error ("too many alternatives in %<asm%>");
1190 const char *constraint
1191 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tmp
)));
1193 if (n_occurrences (',', constraint
) != nalternatives
)
1195 error ("operand constraints for %<asm%> differ "
1196 "in number of alternatives");
1200 if (TREE_CHAIN (tmp
))
1201 tmp
= TREE_CHAIN (tmp
);
1203 tmp
= next
, next
= 0;
1210 /* A subroutine of expand_asm_operands. Check that all operand names
1211 are unique. Return true if so. We rely on the fact that these names
1212 are identifiers, and so have been canonicalized by get_identifier,
1213 so all we need are pointer comparisons. */
1216 check_unique_operand_names (tree outputs
, tree inputs
, tree labels
)
1218 tree i
, j
, i_name
= NULL_TREE
;
1220 for (i
= outputs
; i
; i
= TREE_CHAIN (i
))
1222 i_name
= TREE_PURPOSE (TREE_PURPOSE (i
));
1226 for (j
= TREE_CHAIN (i
); j
; j
= TREE_CHAIN (j
))
1227 if (simple_cst_equal (i_name
, TREE_PURPOSE (TREE_PURPOSE (j
))))
1231 for (i
= inputs
; i
; i
= TREE_CHAIN (i
))
1233 i_name
= TREE_PURPOSE (TREE_PURPOSE (i
));
1237 for (j
= TREE_CHAIN (i
); j
; j
= TREE_CHAIN (j
))
1238 if (simple_cst_equal (i_name
, TREE_PURPOSE (TREE_PURPOSE (j
))))
1240 for (j
= outputs
; j
; j
= TREE_CHAIN (j
))
1241 if (simple_cst_equal (i_name
, TREE_PURPOSE (TREE_PURPOSE (j
))))
1245 for (i
= labels
; i
; i
= TREE_CHAIN (i
))
1247 i_name
= TREE_PURPOSE (i
);
1251 for (j
= TREE_CHAIN (i
); j
; j
= TREE_CHAIN (j
))
1252 if (simple_cst_equal (i_name
, TREE_PURPOSE (j
)))
1254 for (j
= inputs
; j
; j
= TREE_CHAIN (j
))
1255 if (simple_cst_equal (i_name
, TREE_PURPOSE (TREE_PURPOSE (j
))))
1262 error ("duplicate asm operand name %qs", TREE_STRING_POINTER (i_name
));
1266 /* A subroutine of expand_asm_operands. Resolve the names of the operands
1267 in *POUTPUTS and *PINPUTS to numbers, and replace the name expansions in
1268 STRING and in the constraints to those numbers. */
1271 resolve_asm_operand_names (tree string
, tree outputs
, tree inputs
, tree labels
)
1278 check_unique_operand_names (outputs
, inputs
, labels
);
1280 /* Substitute [<name>] in input constraint strings. There should be no
1281 named operands in output constraints. */
1282 for (t
= inputs
; t
; t
= TREE_CHAIN (t
))
1284 c
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t
)));
1285 if (strchr (c
, '[') != NULL
)
1287 p
= buffer
= xstrdup (c
);
1288 while ((p
= strchr (p
, '[')) != NULL
)
1289 p
= resolve_operand_name_1 (p
, outputs
, inputs
, NULL
);
1290 TREE_VALUE (TREE_PURPOSE (t
))
1291 = build_string (strlen (buffer
), buffer
);
1296 /* Now check for any needed substitutions in the template. */
1297 c
= TREE_STRING_POINTER (string
);
1298 while ((c
= strchr (c
, '%')) != NULL
)
1302 else if (ISALPHA (c
[1]) && c
[2] == '[')
1306 c
+= 1 + (c
[1] == '%');
1313 /* OK, we need to make a copy so we can perform the substitutions.
1314 Assume that we will not need extra space--we get to remove '['
1315 and ']', which means we cannot have a problem until we have more
1316 than 999 operands. */
1317 buffer
= xstrdup (TREE_STRING_POINTER (string
));
1318 p
= buffer
+ (c
- TREE_STRING_POINTER (string
));
1320 while ((p
= strchr (p
, '%')) != NULL
)
1324 else if (ISALPHA (p
[1]) && p
[2] == '[')
1328 p
+= 1 + (p
[1] == '%');
1332 p
= resolve_operand_name_1 (p
, outputs
, inputs
, labels
);
1335 string
= build_string (strlen (buffer
), buffer
);
1342 /* A subroutine of resolve_operand_names. P points to the '[' for a
1343 potential named operand of the form [<name>]. In place, replace
1344 the name and brackets with a number. Return a pointer to the
1345 balance of the string after substitution. */
1348 resolve_operand_name_1 (char *p
, tree outputs
, tree inputs
, tree labels
)
1354 /* Collect the operand name. */
1355 q
= strchr (++p
, ']');
1358 error ("missing close brace for named operand");
1359 return strchr (p
, '\0');
1363 /* Resolve the name to a number. */
1364 for (op
= 0, t
= outputs
; t
; t
= TREE_CHAIN (t
), op
++)
1366 tree name
= TREE_PURPOSE (TREE_PURPOSE (t
));
1367 if (name
&& strcmp (TREE_STRING_POINTER (name
), p
) == 0)
1370 for (t
= inputs
; t
; t
= TREE_CHAIN (t
), op
++)
1372 tree name
= TREE_PURPOSE (TREE_PURPOSE (t
));
1373 if (name
&& strcmp (TREE_STRING_POINTER (name
), p
) == 0)
1376 for (t
= labels
; t
; t
= TREE_CHAIN (t
), op
++)
1378 tree name
= TREE_PURPOSE (t
);
1379 if (name
&& strcmp (TREE_STRING_POINTER (name
), p
) == 0)
1383 error ("undefined named operand %qs", identifier_to_locale (p
));
1387 /* Replace the name with the number. Unfortunately, not all libraries
1388 get the return value of sprintf correct, so search for the end of the
1389 generated string by hand. */
1390 sprintf (--p
, "%d", op
);
1391 p
= strchr (p
, '\0');
1393 /* Verify the no extra buffer space assumption. */
1394 gcc_assert (p
<= q
);
1396 /* Shift the rest of the buffer down to fill the gap. */
1397 memmove (p
, q
+ 1, strlen (q
+ 1) + 1);
1402 /* Generate RTL to evaluate the expression EXP. */
1405 expand_expr_stmt (tree exp
)
1410 value
= expand_expr (exp
, const0_rtx
, VOIDmode
, EXPAND_NORMAL
);
1411 type
= TREE_TYPE (exp
);
1413 /* If all we do is reference a volatile value in memory,
1414 copy it to a register to be sure it is actually touched. */
1415 if (value
&& MEM_P (value
) && TREE_THIS_VOLATILE (exp
))
1417 if (TYPE_MODE (type
) == VOIDmode
)
1419 else if (TYPE_MODE (type
) != BLKmode
)
1420 copy_to_reg (value
);
1423 rtx lab
= gen_label_rtx ();
1425 /* Compare the value with itself to reference it. */
1426 emit_cmp_and_jump_insns (value
, value
, EQ
,
1427 expand_normal (TYPE_SIZE (type
)),
1433 /* Free any temporaries used to evaluate this expression. */
1438 /* Generate RTL to return from the current function, with no value.
1439 (That is, we do not do anything about returning any value.) */
1442 expand_null_return (void)
1444 /* If this function was declared to return a value, but we
1445 didn't, clobber the return registers so that they are not
1446 propagated live to the rest of the function. */
1447 clobber_return_register ();
1449 expand_null_return_1 ();
1452 /* Generate RTL to return directly from the current function.
1453 (That is, we bypass any return value.) */
1456 expand_naked_return (void)
1460 clear_pending_stack_adjust ();
1461 do_pending_stack_adjust ();
1463 end_label
= naked_return_label
;
1465 end_label
= naked_return_label
= gen_label_rtx ();
1467 emit_jump (end_label
);
1470 /* Generate RTL to return from the current function, with value VAL. */
1473 expand_value_return (rtx val
)
1475 /* Copy the value to the return location unless it's already there. */
1477 tree decl
= DECL_RESULT (current_function_decl
);
1478 rtx return_reg
= DECL_RTL (decl
);
1479 if (return_reg
!= val
)
1481 tree funtype
= TREE_TYPE (current_function_decl
);
1482 tree type
= TREE_TYPE (decl
);
1483 int unsignedp
= TYPE_UNSIGNED (type
);
1484 enum machine_mode old_mode
= DECL_MODE (decl
);
1485 enum machine_mode mode
;
1486 if (DECL_BY_REFERENCE (decl
))
1487 mode
= promote_function_mode (type
, old_mode
, &unsignedp
, funtype
, 2);
1489 mode
= promote_function_mode (type
, old_mode
, &unsignedp
, funtype
, 1);
1491 if (mode
!= old_mode
)
1492 val
= convert_modes (mode
, old_mode
, val
, unsignedp
);
1494 if (GET_CODE (return_reg
) == PARALLEL
)
1495 emit_group_load (return_reg
, val
, type
, int_size_in_bytes (type
));
1497 emit_move_insn (return_reg
, val
);
1500 expand_null_return_1 ();
1503 /* Output a return with no value. */
1506 expand_null_return_1 (void)
1508 clear_pending_stack_adjust ();
1509 do_pending_stack_adjust ();
1510 emit_jump (return_label
);
1513 /* Generate RTL to evaluate the expression RETVAL and return it
1514 from the current function. */
1517 expand_return (tree retval
)
1523 /* If function wants no value, give it none. */
1524 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl
))) == VOID_TYPE
)
1526 expand_normal (retval
);
1527 expand_null_return ();
1531 if (retval
== error_mark_node
)
1533 /* Treat this like a return of no value from a function that
1535 expand_null_return ();
1538 else if ((TREE_CODE (retval
) == MODIFY_EXPR
1539 || TREE_CODE (retval
) == INIT_EXPR
)
1540 && TREE_CODE (TREE_OPERAND (retval
, 0)) == RESULT_DECL
)
1541 retval_rhs
= TREE_OPERAND (retval
, 1);
1543 retval_rhs
= retval
;
1545 result_rtl
= DECL_RTL (DECL_RESULT (current_function_decl
));
1547 /* If we are returning the RESULT_DECL, then the value has already
1548 been stored into it, so we don't have to do anything special. */
1549 if (TREE_CODE (retval_rhs
) == RESULT_DECL
)
1550 expand_value_return (result_rtl
);
1552 /* If the result is an aggregate that is being returned in one (or more)
1553 registers, load the registers here. */
1555 else if (retval_rhs
!= 0
1556 && TYPE_MODE (TREE_TYPE (retval_rhs
)) == BLKmode
1557 && REG_P (result_rtl
))
1559 val
= copy_blkmode_to_reg (GET_MODE (result_rtl
), retval_rhs
);
1562 /* Use the mode of the result value on the return register. */
1563 PUT_MODE (result_rtl
, GET_MODE (val
));
1564 expand_value_return (val
);
1567 expand_null_return ();
1569 else if (retval_rhs
!= 0
1570 && !VOID_TYPE_P (TREE_TYPE (retval_rhs
))
1571 && (REG_P (result_rtl
)
1572 || (GET_CODE (result_rtl
) == PARALLEL
)))
1574 /* Calculate the return value into a temporary (usually a pseudo
1576 tree ot
= TREE_TYPE (DECL_RESULT (current_function_decl
));
1577 tree nt
= build_qualified_type (ot
, TYPE_QUALS (ot
) | TYPE_QUAL_CONST
);
1579 val
= assign_temp (nt
, 0, 1);
1580 val
= expand_expr (retval_rhs
, val
, GET_MODE (val
), EXPAND_NORMAL
);
1581 val
= force_not_mem (val
);
1582 /* Return the calculated value. */
1583 expand_value_return (val
);
1587 /* No hard reg used; calculate value into hard return reg. */
1588 expand_expr (retval
, const0_rtx
, VOIDmode
, EXPAND_NORMAL
);
1589 expand_value_return (result_rtl
);
1593 /* Emit code to restore vital registers at the beginning of a nonlocal goto
1596 expand_nl_goto_receiver (void)
1600 /* Clobber the FP when we get here, so we have to make sure it's
1601 marked as used by this function. */
1602 emit_use (hard_frame_pointer_rtx
);
1604 /* Mark the static chain as clobbered here so life information
1605 doesn't get messed up for it. */
1606 chain
= targetm
.calls
.static_chain (current_function_decl
, true);
1607 if (chain
&& REG_P (chain
))
1608 emit_clobber (chain
);
1610 #ifdef HAVE_nonlocal_goto
1611 if (! HAVE_nonlocal_goto
)
1613 /* First adjust our frame pointer to its actual value. It was
1614 previously set to the start of the virtual area corresponding to
1615 the stacked variables when we branched here and now needs to be
1616 adjusted to the actual hardware fp value.
1618 Assignments are to virtual registers are converted by
1619 instantiate_virtual_regs into the corresponding assignment
1620 to the underlying register (fp in this case) that makes
1621 the original assignment true.
1622 So the following insn will actually be
1623 decrementing fp by STARTING_FRAME_OFFSET. */
1624 emit_move_insn (virtual_stack_vars_rtx
, hard_frame_pointer_rtx
);
1626 #if !HARD_FRAME_POINTER_IS_ARG_POINTER
1627 if (fixed_regs
[ARG_POINTER_REGNUM
])
1629 #ifdef ELIMINABLE_REGS
1630 /* If the argument pointer can be eliminated in favor of the
1631 frame pointer, we don't need to restore it. We assume here
1632 that if such an elimination is present, it can always be used.
1633 This is the case on all known machines; if we don't make this
1634 assumption, we do unnecessary saving on many machines. */
1635 static const struct elims
{const int from
, to
;} elim_regs
[] = ELIMINABLE_REGS
;
1638 for (i
= 0; i
< ARRAY_SIZE (elim_regs
); i
++)
1639 if (elim_regs
[i
].from
== ARG_POINTER_REGNUM
1640 && elim_regs
[i
].to
== HARD_FRAME_POINTER_REGNUM
)
1643 if (i
== ARRAY_SIZE (elim_regs
))
1646 /* Now restore our arg pointer from the address at which it
1647 was saved in our stack frame. */
1648 emit_move_insn (crtl
->args
.internal_arg_pointer
,
1649 copy_to_reg (get_arg_pointer_save_area ()));
1654 #ifdef HAVE_nonlocal_goto_receiver
1655 if (HAVE_nonlocal_goto_receiver
)
1656 emit_insn (gen_nonlocal_goto_receiver ());
1659 /* We must not allow the code we just generated to be reordered by
1660 scheduling. Specifically, the update of the frame pointer must
1661 happen immediately, not later. */
1662 emit_insn (gen_blockage ());
1665 /* Emit code to save the current value of stack. */
1667 expand_stack_save (void)
1671 do_pending_stack_adjust ();
1672 emit_stack_save (SAVE_BLOCK
, &ret
);
1676 /* Emit code to restore the current value of stack. */
1678 expand_stack_restore (tree var
)
1680 rtx prev
, sa
= expand_normal (var
);
1682 sa
= convert_memory_address (Pmode
, sa
);
1684 prev
= get_last_insn ();
1685 emit_stack_restore (SAVE_BLOCK
, sa
);
1686 fixup_args_size_notes (prev
, get_last_insn (), 0);
1689 /* Do the insertion of a case label into case_list. The labels are
1690 fed to us in descending order from the sorted vector of case labels used
1691 in the tree part of the middle end. So the list we construct is
1692 sorted in ascending order. The bounds on the case range, LOW and HIGH,
1693 are converted to case's index type TYPE. Note that the original type
1694 of the case index in the source code is usually "lost" during
1695 gimplification due to type promotion, but the case labels retain the
1698 static struct case_node
*
1699 add_case_node (struct case_node
*head
, tree type
, tree low
, tree high
,
1700 tree label
, alloc_pool case_node_pool
)
1702 struct case_node
*r
;
1704 gcc_checking_assert (low
);
1705 gcc_checking_assert (! high
|| (TREE_TYPE (low
) == TREE_TYPE (high
)));
1707 /* Add this label to the chain. Make sure to drop overflow flags. */
1708 r
= (struct case_node
*) pool_alloc (case_node_pool
);
1709 r
->low
= build_int_cst_wide (type
, TREE_INT_CST_LOW (low
),
1710 TREE_INT_CST_HIGH (low
));
1711 r
->high
= build_int_cst_wide (type
, TREE_INT_CST_LOW (high
),
1712 TREE_INT_CST_HIGH (high
));
1713 r
->code_label
= label
;
1714 r
->parent
= r
->left
= NULL
;
1719 /* Dump ROOT, a list or tree of case nodes, to file. */
1722 dump_case_nodes (FILE *f
, struct case_node
*root
,
1723 int indent_step
, int indent_level
)
1725 HOST_WIDE_INT low
, high
;
1731 dump_case_nodes (f
, root
->left
, indent_step
, indent_level
);
1733 low
= tree_low_cst (root
->low
, 0);
1734 high
= tree_low_cst (root
->high
, 0);
1738 fprintf(f
, "%*s" HOST_WIDE_INT_PRINT_DEC
,
1739 indent_step
* indent_level
, "", low
);
1741 fprintf(f
, "%*s" HOST_WIDE_INT_PRINT_DEC
" ... " HOST_WIDE_INT_PRINT_DEC
,
1742 indent_step
* indent_level
, "", low
, high
);
1745 dump_case_nodes (f
, root
->right
, indent_step
, indent_level
);
1749 #define HAVE_casesi 0
1752 #ifndef HAVE_tablejump
1753 #define HAVE_tablejump 0
1756 /* Return the smallest number of different values for which it is best to use a
1757 jump-table instead of a tree of conditional branches. */
1760 case_values_threshold (void)
1762 unsigned int threshold
= PARAM_VALUE (PARAM_CASE_VALUES_THRESHOLD
);
1765 threshold
= targetm
.case_values_threshold ();
1770 /* Return true if a switch should be expanded as a decision tree.
1771 RANGE is the difference between highest and lowest case.
1772 UNIQ is number of unique case node targets, not counting the default case.
1773 COUNT is the number of comparisons needed, not counting the default case. */
1776 expand_switch_as_decision_tree_p (tree range
,
1777 unsigned int uniq ATTRIBUTE_UNUSED
,
1782 /* If neither casesi or tablejump is available, or flag_jump_tables
1783 over-ruled us, we really have no choice. */
1784 if (!HAVE_casesi
&& !HAVE_tablejump
)
1786 if (!flag_jump_tables
)
1789 /* If the switch is relatively small such that the cost of one
1790 indirect jump on the target are higher than the cost of a
1791 decision tree, go with the decision tree.
1793 If range of values is much bigger than number of values,
1794 or if it is too large to represent in a HOST_WIDE_INT,
1795 make a sequence of conditional branches instead of a dispatch.
1797 The definition of "much bigger" depends on whether we are
1798 optimizing for size or for speed. If the former, the maximum
1799 ratio range/count = 3, because this was found to be the optimal
1800 ratio for size on i686-pc-linux-gnu, see PR11823. The ratio
1801 10 is much older, and was probably selected after an extensive
1802 benchmarking investigation on numerous platforms. Or maybe it
1803 just made sense to someone at some point in the history of GCC,
1805 max_ratio
= optimize_insn_for_size_p () ? 3 : 10;
1806 if (count
< case_values_threshold ()
1807 || ! host_integerp (range
, /*pos=*/1)
1808 || compare_tree_int (range
, max_ratio
* count
) > 0)
1814 /* Generate a decision tree, switching on INDEX_EXPR and jumping to
1815 one of the labels in CASE_LIST or to the DEFAULT_LABEL.
1817 We generate a binary decision tree to select the appropriate target
1818 code. This is done as follows:
1820 If the index is a short or char that we do not have
1821 an insn to handle comparisons directly, convert it to
1822 a full integer now, rather than letting each comparison
1823 generate the conversion.
1825 Load the index into a register.
1827 The list of cases is rearranged into a binary tree,
1828 nearly optimal assuming equal probability for each case.
1830 The tree is transformed into RTL, eliminating redundant
1831 test conditions at the same time.
1833 If program flow could reach the end of the decision tree
1834 an unconditional jump to the default code is emitted.
1836 The above process is unaware of the CFG. The caller has to fix up
1837 the CFG itself. This is done in cfgexpand.c. */
1840 emit_case_decision_tree (tree index_expr
, tree index_type
,
1841 struct case_node
*case_list
, rtx default_label
)
1843 rtx index
= expand_normal (index_expr
);
1845 if (GET_MODE_CLASS (GET_MODE (index
)) == MODE_INT
1846 && ! have_insn_for (COMPARE
, GET_MODE (index
)))
1848 int unsignedp
= TYPE_UNSIGNED (index_type
);
1849 enum machine_mode wider_mode
;
1850 for (wider_mode
= GET_MODE (index
); wider_mode
!= VOIDmode
;
1851 wider_mode
= GET_MODE_WIDER_MODE (wider_mode
))
1852 if (have_insn_for (COMPARE
, wider_mode
))
1854 index
= convert_to_mode (wider_mode
, index
, unsignedp
);
1859 do_pending_stack_adjust ();
1863 index
= copy_to_reg (index
);
1864 if (TREE_CODE (index_expr
) == SSA_NAME
)
1865 set_reg_attrs_for_decl_rtl (SSA_NAME_VAR (index_expr
), index
);
1868 balance_case_nodes (&case_list
, NULL
);
1870 /* Don't want to include tree-pass.h here. This code will be moved
1871 to a GIMPLE pass for GCC 4.9 anyway, so for now always dump. */
1872 if (dump_file
&& 1/*(dump_flags & TDF_DETAILS)*/)
1874 int indent_step
= ceil_log2 (TYPE_PRECISION (index_type
)) + 2;
1875 fprintf (dump_file
, ";; Expanding GIMPLE switch as decision tree:\n");
1876 dump_case_nodes (dump_file
, case_list
, indent_step
, 0);
1879 emit_case_nodes (index
, case_list
, default_label
, index_type
);
1881 emit_jump (default_label
);
1884 /* Generate a dispatch tabler, switching on INDEX_EXPR and jumping to
1885 one of the labels in CASE_LIST or to the DEFAULT_LABEL.
1886 MINVAL, MAXVAL, and RANGE are the extrema and range of the case
1887 labels in CASE_LIST.
1889 First, a jump insn is emitted. First we try "casesi". If that
1890 fails, try "tablejump". A target *must* have one of them (or both).
1892 Then, a table with the target labels is emitted.
1894 The process is unaware of the CFG. The caller has to fix up
1895 the CFG itself. This is done in cfgexpand.c. */
1898 emit_case_dispatch_table (tree index_expr
, tree index_type
,
1899 struct case_node
*case_list
, rtx default_label
,
1900 tree minval
, tree maxval
, tree range
)
1903 struct case_node
*n
;
1905 rtx fallback_label
= label_rtx (case_list
->code_label
);
1906 rtx table_label
= gen_label_rtx ();
1908 if (! try_casesi (index_type
, index_expr
, minval
, range
,
1909 table_label
, default_label
, fallback_label
))
1913 /* Index jumptables from zero for suitable values of minval to avoid
1914 a subtraction. For the rationale see:
1915 "http://gcc.gnu.org/ml/gcc-patches/2001-10/msg01234.html". */
1916 if (optimize_insn_for_speed_p ()
1917 && compare_tree_int (minval
, 0) > 0
1918 && compare_tree_int (minval
, 3) < 0)
1920 minval
= build_int_cst (index_type
, 0);
1924 ok
= try_tablejump (index_type
, index_expr
, minval
, range
,
1925 table_label
, default_label
);
1929 /* Get table of labels to jump to, in order of case index. */
1931 ncases
= tree_low_cst (range
, 0) + 1;
1932 labelvec
= XALLOCAVEC (rtx
, ncases
);
1933 memset (labelvec
, 0, ncases
* sizeof (rtx
));
1935 for (n
= case_list
; n
; n
= n
->right
)
1937 /* Compute the low and high bounds relative to the minimum
1938 value since that should fit in a HOST_WIDE_INT while the
1939 actual values may not. */
1941 = tree_low_cst (fold_build2 (MINUS_EXPR
, index_type
,
1942 n
->low
, minval
), 1);
1943 HOST_WIDE_INT i_high
1944 = tree_low_cst (fold_build2 (MINUS_EXPR
, index_type
,
1945 n
->high
, minval
), 1);
1948 for (i
= i_low
; i
<= i_high
; i
++)
1950 = gen_rtx_LABEL_REF (Pmode
, label_rtx (n
->code_label
));
1953 /* Fill in the gaps with the default. We may have gaps at
1954 the beginning if we tried to avoid the minval subtraction,
1955 so substitute some label even if the default label was
1956 deemed unreachable. */
1958 default_label
= fallback_label
;
1959 for (i
= 0; i
< ncases
; i
++)
1960 if (labelvec
[i
] == 0)
1961 labelvec
[i
] = gen_rtx_LABEL_REF (Pmode
, default_label
);
1963 /* Output the table. */
1964 emit_label (table_label
);
1966 if (CASE_VECTOR_PC_RELATIVE
|| flag_pic
)
1967 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE
,
1968 gen_rtx_LABEL_REF (Pmode
, table_label
),
1969 gen_rtvec_v (ncases
, labelvec
),
1970 const0_rtx
, const0_rtx
));
1972 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE
,
1973 gen_rtvec_v (ncases
, labelvec
)));
1975 /* Record no drop-through after the table. */
1979 /* Terminate a case (Pascal/Ada) or switch (C) statement
1980 in which ORIG_INDEX is the expression to be tested.
1981 If ORIG_TYPE is not NULL, it is the original ORIG_INDEX
1982 type as given in the source before any compiler conversions.
1983 Generate the code to test it and jump to the right place. */
1986 expand_case (gimple stmt
)
1988 tree minval
= NULL_TREE
, maxval
= NULL_TREE
, range
= NULL_TREE
;
1989 rtx default_label
= NULL_RTX
;
1990 unsigned int count
, uniq
;
1992 rtx before_case
, end
;
1993 int ncases
= gimple_switch_num_labels (stmt
);
1994 tree index_expr
= gimple_switch_index (stmt
);
1995 tree index_type
= TREE_TYPE (index_expr
);
1998 bitmap label_bitmap
;
2000 /* The insn after which the case dispatch should finally
2001 be emitted. Zero for a dummy. */
2004 /* A list of case labels; it is first built as a list and it may then
2005 be rearranged into a nearly balanced binary tree. */
2006 struct case_node
*case_list
= 0;
2008 /* A pool for case nodes. */
2009 alloc_pool case_node_pool
;
2011 /* An ERROR_MARK occurs for various reasons including invalid data type.
2012 ??? Can this still happen, with GIMPLE and all? */
2013 if (index_type
== error_mark_node
)
2016 /* cleanup_tree_cfg removes all SWITCH_EXPR with their index
2017 expressions being INTEGER_CST. */
2018 gcc_assert (TREE_CODE (index_expr
) != INTEGER_CST
);
2020 case_node_pool
= create_alloc_pool ("struct case_node pool",
2021 sizeof (struct case_node
),
2024 do_pending_stack_adjust ();
2026 /* The default case, if ever taken, is the first element. */
2027 elt
= gimple_switch_label (stmt
, 0);
2028 if (!CASE_LOW (elt
) && !CASE_HIGH (elt
))
2030 default_label
= label_rtx (CASE_LABEL (elt
));
2034 /* Get upper and lower bounds of case values. */
2035 elt
= gimple_switch_label (stmt
, stopi
);
2036 minval
= fold_convert (index_type
, CASE_LOW (elt
));
2037 elt
= gimple_switch_label (stmt
, ncases
- 1);
2038 if (CASE_HIGH (elt
))
2039 maxval
= fold_convert (index_type
, CASE_HIGH (elt
));
2041 maxval
= fold_convert (index_type
, CASE_LOW (elt
));
2043 /* Compute span of values. */
2044 range
= fold_build2 (MINUS_EXPR
, index_type
, maxval
, minval
);
2046 /* Listify the labels queue and gather some numbers to decide
2047 how to expand this switch(). */
2050 label_bitmap
= BITMAP_ALLOC (NULL
);
2051 for (i
= gimple_switch_num_labels (stmt
) - 1; i
>= stopi
; --i
)
2056 elt
= gimple_switch_label (stmt
, i
);
2057 low
= CASE_LOW (elt
);
2059 high
= CASE_HIGH (elt
);
2060 gcc_assert (! high
|| tree_int_cst_lt (low
, high
));
2062 /* Count the elements.
2063 A range counts double, since it requires two compares. */
2068 /* If we have not seen this label yet, then increase the
2069 number of unique case node targets seen. */
2070 lab
= label_rtx (CASE_LABEL (elt
));
2071 if (bitmap_set_bit (label_bitmap
, CODE_LABEL_NUMBER (lab
)))
2074 /* The canonical from of a case label in GIMPLE is that a simple case
2075 has an empty CASE_HIGH. For the casesi and tablejump expanders,
2076 the back ends want simple cases to have high == low. */
2080 case_list
= add_case_node (case_list
, index_type
, low
, high
,
2081 CASE_LABEL (elt
), case_node_pool
);
2083 BITMAP_FREE (label_bitmap
);
2085 /* cleanup_tree_cfg removes all SWITCH_EXPR with a single
2086 destination, such as one with a default case only.
2087 It also removes cases that are out of range for the switch
2088 type, so we should never get a zero here. */
2089 gcc_assert (count
> 0);
2091 before_case
= start
= get_last_insn ();
2093 /* Decide how to expand this switch.
2094 The two options at this point are a dispatch table (casesi or
2095 tablejump) or a decision tree. */
2097 if (expand_switch_as_decision_tree_p (range
, uniq
, count
))
2098 emit_case_decision_tree (index_expr
, index_type
,
2099 case_list
, default_label
);
2101 emit_case_dispatch_table (index_expr
, index_type
,
2102 case_list
, default_label
,
2103 minval
, maxval
, range
);
2105 before_case
= NEXT_INSN (before_case
);
2106 end
= get_last_insn ();
2107 reorder_insns (before_case
, end
, start
);
2110 free_alloc_pool (case_node_pool
);
2113 /* Generate code to jump to LABEL if OP0 and OP1 are equal in mode MODE. */
2116 do_jump_if_equal (enum machine_mode mode
, rtx op0
, rtx op1
, rtx label
,
2119 do_compare_rtx_and_jump (op0
, op1
, EQ
, unsignedp
, mode
,
2120 NULL_RTX
, NULL_RTX
, label
, -1);
2123 /* Take an ordered list of case nodes
2124 and transform them into a near optimal binary tree,
2125 on the assumption that any target code selection value is as
2126 likely as any other.
2128 The transformation is performed by splitting the ordered
2129 list into two equal sections plus a pivot. The parts are
2130 then attached to the pivot as left and right branches. Each
2131 branch is then transformed recursively. */
2134 balance_case_nodes (case_node_ptr
*head
, case_node_ptr parent
)
2146 /* Count the number of entries on branch. Also count the ranges. */
2150 if (!tree_int_cst_equal (np
->low
, np
->high
))
2159 /* Split this list if it is long enough for that to help. */
2163 /* If there are just three nodes, split at the middle one. */
2165 npp
= &(*npp
)->right
;
2168 /* Find the place in the list that bisects the list's total cost,
2169 where ranges count as 2.
2170 Here I gets half the total cost. */
2171 i
= (i
+ ranges
+ 1) / 2;
2174 /* Skip nodes while their cost does not reach that amount. */
2175 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
2180 npp
= &(*npp
)->right
;
2185 np
->parent
= parent
;
2188 /* Optimize each of the two split parts. */
2189 balance_case_nodes (&np
->left
, np
);
2190 balance_case_nodes (&np
->right
, np
);
2194 /* Else leave this branch as one level,
2195 but fill in `parent' fields. */
2197 np
->parent
= parent
;
2198 for (; np
->right
; np
= np
->right
)
2199 np
->right
->parent
= np
;
2204 /* Search the parent sections of the case node tree
2205 to see if a test for the lower bound of NODE would be redundant.
2206 INDEX_TYPE is the type of the index expression.
2208 The instructions to generate the case decision tree are
2209 output in the same order as nodes are processed so it is
2210 known that if a parent node checks the range of the current
2211 node minus one that the current node is bounded at its lower
2212 span. Thus the test would be redundant. */
2215 node_has_low_bound (case_node_ptr node
, tree index_type
)
2218 case_node_ptr pnode
;
2220 /* If the lower bound of this node is the lowest value in the index type,
2221 we need not test it. */
2223 if (tree_int_cst_equal (node
->low
, TYPE_MIN_VALUE (index_type
)))
2226 /* If this node has a left branch, the value at the left must be less
2227 than that at this node, so it cannot be bounded at the bottom and
2228 we need not bother testing any further. */
2233 low_minus_one
= fold_build2 (MINUS_EXPR
, TREE_TYPE (node
->low
),
2235 build_int_cst (TREE_TYPE (node
->low
), 1));
2237 /* If the subtraction above overflowed, we can't verify anything.
2238 Otherwise, look for a parent that tests our value - 1. */
2240 if (! tree_int_cst_lt (low_minus_one
, node
->low
))
2243 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
2244 if (tree_int_cst_equal (low_minus_one
, pnode
->high
))
2250 /* Search the parent sections of the case node tree
2251 to see if a test for the upper bound of NODE would be redundant.
2252 INDEX_TYPE is the type of the index expression.
2254 The instructions to generate the case decision tree are
2255 output in the same order as nodes are processed so it is
2256 known that if a parent node checks the range of the current
2257 node plus one that the current node is bounded at its upper
2258 span. Thus the test would be redundant. */
2261 node_has_high_bound (case_node_ptr node
, tree index_type
)
2264 case_node_ptr pnode
;
2266 /* If there is no upper bound, obviously no test is needed. */
2268 if (TYPE_MAX_VALUE (index_type
) == NULL
)
2271 /* If the upper bound of this node is the highest value in the type
2272 of the index expression, we need not test against it. */
2274 if (tree_int_cst_equal (node
->high
, TYPE_MAX_VALUE (index_type
)))
2277 /* If this node has a right branch, the value at the right must be greater
2278 than that at this node, so it cannot be bounded at the top and
2279 we need not bother testing any further. */
2284 high_plus_one
= fold_build2 (PLUS_EXPR
, TREE_TYPE (node
->high
),
2286 build_int_cst (TREE_TYPE (node
->high
), 1));
2288 /* If the addition above overflowed, we can't verify anything.
2289 Otherwise, look for a parent that tests our value + 1. */
2291 if (! tree_int_cst_lt (node
->high
, high_plus_one
))
2294 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
2295 if (tree_int_cst_equal (high_plus_one
, pnode
->low
))
2301 /* Search the parent sections of the
2302 case node tree to see if both tests for the upper and lower
2303 bounds of NODE would be redundant. */
2306 node_is_bounded (case_node_ptr node
, tree index_type
)
2308 return (node_has_low_bound (node
, index_type
)
2309 && node_has_high_bound (node
, index_type
));
2312 /* Emit step-by-step code to select a case for the value of INDEX.
2313 The thus generated decision tree follows the form of the
2314 case-node binary tree NODE, whose nodes represent test conditions.
2315 INDEX_TYPE is the type of the index of the switch.
2317 Care is taken to prune redundant tests from the decision tree
2318 by detecting any boundary conditions already checked by
2319 emitted rtx. (See node_has_high_bound, node_has_low_bound
2320 and node_is_bounded, above.)
2322 Where the test conditions can be shown to be redundant we emit
2323 an unconditional jump to the target code. As a further
2324 optimization, the subordinates of a tree node are examined to
2325 check for bounded nodes. In this case conditional and/or
2326 unconditional jumps as a result of the boundary check for the
2327 current node are arranged to target the subordinates associated
2328 code for out of bound conditions on the current node.
2330 We can assume that when control reaches the code generated here,
2331 the index value has already been compared with the parents
2332 of this node, and determined to be on the same side of each parent
2333 as this node is. Thus, if this node tests for the value 51,
2334 and a parent tested for 52, we don't need to consider
2335 the possibility of a value greater than 51. If another parent
2336 tests for the value 50, then this node need not test anything. */
2339 emit_case_nodes (rtx index
, case_node_ptr node
, rtx default_label
,
2342 /* If INDEX has an unsigned type, we must make unsigned branches. */
2343 int unsignedp
= TYPE_UNSIGNED (index_type
);
2344 enum machine_mode mode
= GET_MODE (index
);
2345 enum machine_mode imode
= TYPE_MODE (index_type
);
2347 /* Handle indices detected as constant during RTL expansion. */
2348 if (mode
== VOIDmode
)
2351 /* See if our parents have already tested everything for us.
2352 If they have, emit an unconditional jump for this node. */
2353 if (node_is_bounded (node
, index_type
))
2354 emit_jump (label_rtx (node
->code_label
));
2356 else if (tree_int_cst_equal (node
->low
, node
->high
))
2358 /* Node is single valued. First see if the index expression matches
2359 this node and then check our children, if any. */
2361 do_jump_if_equal (mode
, index
,
2362 convert_modes (mode
, imode
,
2363 expand_normal (node
->low
),
2365 label_rtx (node
->code_label
), unsignedp
);
2367 if (node
->right
!= 0 && node
->left
!= 0)
2369 /* This node has children on both sides.
2370 Dispatch to one side or the other
2371 by comparing the index value with this node's value.
2372 If one subtree is bounded, check that one first,
2373 so we can avoid real branches in the tree. */
2375 if (node_is_bounded (node
->right
, index_type
))
2377 emit_cmp_and_jump_insns (index
,
2380 expand_normal (node
->high
),
2382 GT
, NULL_RTX
, mode
, unsignedp
,
2383 label_rtx (node
->right
->code_label
));
2384 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
2387 else if (node_is_bounded (node
->left
, index_type
))
2389 emit_cmp_and_jump_insns (index
,
2392 expand_normal (node
->high
),
2394 LT
, NULL_RTX
, mode
, unsignedp
,
2395 label_rtx (node
->left
->code_label
));
2396 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
2399 /* If both children are single-valued cases with no
2400 children, finish up all the work. This way, we can save
2401 one ordered comparison. */
2402 else if (tree_int_cst_equal (node
->right
->low
, node
->right
->high
)
2403 && node
->right
->left
== 0
2404 && node
->right
->right
== 0
2405 && tree_int_cst_equal (node
->left
->low
, node
->left
->high
)
2406 && node
->left
->left
== 0
2407 && node
->left
->right
== 0)
2409 /* Neither node is bounded. First distinguish the two sides;
2410 then emit the code for one side at a time. */
2412 /* See if the value matches what the right hand side
2414 do_jump_if_equal (mode
, index
,
2415 convert_modes (mode
, imode
,
2416 expand_normal (node
->right
->low
),
2418 label_rtx (node
->right
->code_label
),
2421 /* See if the value matches what the left hand side
2423 do_jump_if_equal (mode
, index
,
2424 convert_modes (mode
, imode
,
2425 expand_normal (node
->left
->low
),
2427 label_rtx (node
->left
->code_label
),
2433 /* Neither node is bounded. First distinguish the two sides;
2434 then emit the code for one side at a time. */
2437 = build_decl (CURR_INSN_LOCATION
,
2438 LABEL_DECL
, NULL_TREE
, NULL_TREE
);
2440 /* See if the value is on the right. */
2441 emit_cmp_and_jump_insns (index
,
2444 expand_normal (node
->high
),
2446 GT
, NULL_RTX
, mode
, unsignedp
,
2447 label_rtx (test_label
));
2449 /* Value must be on the left.
2450 Handle the left-hand subtree. */
2451 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
2452 /* If left-hand subtree does nothing,
2455 emit_jump (default_label
);
2457 /* Code branches here for the right-hand subtree. */
2458 expand_label (test_label
);
2459 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
2463 else if (node
->right
!= 0 && node
->left
== 0)
2465 /* Here we have a right child but no left so we issue a conditional
2466 branch to default and process the right child.
2468 Omit the conditional branch to default if the right child
2469 does not have any children and is single valued; it would
2470 cost too much space to save so little time. */
2472 if (node
->right
->right
|| node
->right
->left
2473 || !tree_int_cst_equal (node
->right
->low
, node
->right
->high
))
2475 if (!node_has_low_bound (node
, index_type
))
2477 emit_cmp_and_jump_insns (index
,
2480 expand_normal (node
->high
),
2482 LT
, NULL_RTX
, mode
, unsignedp
,
2486 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
2489 /* We cannot process node->right normally
2490 since we haven't ruled out the numbers less than
2491 this node's value. So handle node->right explicitly. */
2492 do_jump_if_equal (mode
, index
,
2495 expand_normal (node
->right
->low
),
2497 label_rtx (node
->right
->code_label
), unsignedp
);
2500 else if (node
->right
== 0 && node
->left
!= 0)
2502 /* Just one subtree, on the left. */
2503 if (node
->left
->left
|| node
->left
->right
2504 || !tree_int_cst_equal (node
->left
->low
, node
->left
->high
))
2506 if (!node_has_high_bound (node
, index_type
))
2508 emit_cmp_and_jump_insns (index
,
2511 expand_normal (node
->high
),
2513 GT
, NULL_RTX
, mode
, unsignedp
,
2517 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
2520 /* We cannot process node->left normally
2521 since we haven't ruled out the numbers less than
2522 this node's value. So handle node->left explicitly. */
2523 do_jump_if_equal (mode
, index
,
2526 expand_normal (node
->left
->low
),
2528 label_rtx (node
->left
->code_label
), unsignedp
);
2533 /* Node is a range. These cases are very similar to those for a single
2534 value, except that we do not start by testing whether this node
2535 is the one to branch to. */
2537 if (node
->right
!= 0 && node
->left
!= 0)
2539 /* Node has subtrees on both sides.
2540 If the right-hand subtree is bounded,
2541 test for it first, since we can go straight there.
2542 Otherwise, we need to make a branch in the control structure,
2543 then handle the two subtrees. */
2544 tree test_label
= 0;
2546 if (node_is_bounded (node
->right
, index_type
))
2547 /* Right hand node is fully bounded so we can eliminate any
2548 testing and branch directly to the target code. */
2549 emit_cmp_and_jump_insns (index
,
2552 expand_normal (node
->high
),
2554 GT
, NULL_RTX
, mode
, unsignedp
,
2555 label_rtx (node
->right
->code_label
));
2558 /* Right hand node requires testing.
2559 Branch to a label where we will handle it later. */
2561 test_label
= build_decl (CURR_INSN_LOCATION
,
2562 LABEL_DECL
, NULL_TREE
, NULL_TREE
);
2563 emit_cmp_and_jump_insns (index
,
2566 expand_normal (node
->high
),
2568 GT
, NULL_RTX
, mode
, unsignedp
,
2569 label_rtx (test_label
));
2572 /* Value belongs to this node or to the left-hand subtree. */
2574 emit_cmp_and_jump_insns (index
,
2577 expand_normal (node
->low
),
2579 GE
, NULL_RTX
, mode
, unsignedp
,
2580 label_rtx (node
->code_label
));
2582 /* Handle the left-hand subtree. */
2583 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
2585 /* If right node had to be handled later, do that now. */
2589 /* If the left-hand subtree fell through,
2590 don't let it fall into the right-hand subtree. */
2592 emit_jump (default_label
);
2594 expand_label (test_label
);
2595 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
2599 else if (node
->right
!= 0 && node
->left
== 0)
2601 /* Deal with values to the left of this node,
2602 if they are possible. */
2603 if (!node_has_low_bound (node
, index_type
))
2605 emit_cmp_and_jump_insns (index
,
2608 expand_normal (node
->low
),
2610 LT
, NULL_RTX
, mode
, unsignedp
,
2614 /* Value belongs to this node or to the right-hand subtree. */
2616 emit_cmp_and_jump_insns (index
,
2619 expand_normal (node
->high
),
2621 LE
, NULL_RTX
, mode
, unsignedp
,
2622 label_rtx (node
->code_label
));
2624 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
2627 else if (node
->right
== 0 && node
->left
!= 0)
2629 /* Deal with values to the right of this node,
2630 if they are possible. */
2631 if (!node_has_high_bound (node
, index_type
))
2633 emit_cmp_and_jump_insns (index
,
2636 expand_normal (node
->high
),
2638 GT
, NULL_RTX
, mode
, unsignedp
,
2642 /* Value belongs to this node or to the left-hand subtree. */
2644 emit_cmp_and_jump_insns (index
,
2647 expand_normal (node
->low
),
2649 GE
, NULL_RTX
, mode
, unsignedp
,
2650 label_rtx (node
->code_label
));
2652 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
2657 /* Node has no children so we check low and high bounds to remove
2658 redundant tests. Only one of the bounds can exist,
2659 since otherwise this node is bounded--a case tested already. */
2660 int high_bound
= node_has_high_bound (node
, index_type
);
2661 int low_bound
= node_has_low_bound (node
, index_type
);
2663 if (!high_bound
&& low_bound
)
2665 emit_cmp_and_jump_insns (index
,
2668 expand_normal (node
->high
),
2670 GT
, NULL_RTX
, mode
, unsignedp
,
2674 else if (!low_bound
&& high_bound
)
2676 emit_cmp_and_jump_insns (index
,
2679 expand_normal (node
->low
),
2681 LT
, NULL_RTX
, mode
, unsignedp
,
2684 else if (!low_bound
&& !high_bound
)
2686 /* Widen LOW and HIGH to the same width as INDEX. */
2687 tree type
= lang_hooks
.types
.type_for_mode (mode
, unsignedp
);
2688 tree low
= build1 (CONVERT_EXPR
, type
, node
->low
);
2689 tree high
= build1 (CONVERT_EXPR
, type
, node
->high
);
2690 rtx low_rtx
, new_index
, new_bound
;
2692 /* Instead of doing two branches, emit one unsigned branch for
2693 (index-low) > (high-low). */
2694 low_rtx
= expand_expr (low
, NULL_RTX
, mode
, EXPAND_NORMAL
);
2695 new_index
= expand_simple_binop (mode
, MINUS
, index
, low_rtx
,
2696 NULL_RTX
, unsignedp
,
2698 new_bound
= expand_expr (fold_build2 (MINUS_EXPR
, type
,
2700 NULL_RTX
, mode
, EXPAND_NORMAL
);
2702 emit_cmp_and_jump_insns (new_index
, new_bound
, GT
, NULL_RTX
,
2703 mode
, 1, default_label
);
2706 emit_jump (label_rtx (node
->code_label
));