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Commit | Line | Data |
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5e6908ea | 1 | /* Expands front end tree to back end RTL for GCC |
4559fd9e | 2 | Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, |
a6dd4094 | 3 | 1998, 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc. |
28d81abb | 4 | |
1322177d | 5 | This file is part of GCC. |
28d81abb | 6 | |
1322177d LB |
7 | GCC is free software; you can redistribute it and/or modify it under |
8 | the terms of the GNU General Public License as published by the Free | |
9 | Software Foundation; either version 2, or (at your option) any later | |
10 | version. | |
28d81abb | 11 | |
1322177d LB |
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
28d81abb RK |
16 | |
17 | You should have received a copy of the GNU General Public License | |
1322177d LB |
18 | along with GCC; see the file COPYING. If not, write to the Free |
19 | Software Foundation, 59 Temple Place - Suite 330, Boston, MA | |
20 | 02111-1307, USA. */ | |
28d81abb | 21 | |
28d81abb RK |
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. | |
28d81abb | 24 | The functions whose names start with `expand_' are called by the |
7efcb746 | 25 | expander to generate RTL instructions for various kinds of constructs. */ |
28d81abb RK |
26 | |
27 | #include "config.h" | |
670ee920 | 28 | #include "system.h" |
4977bab6 ZW |
29 | #include "coretypes.h" |
30 | #include "tm.h" | |
ccd043a9 | 31 | |
28d81abb RK |
32 | #include "rtl.h" |
33 | #include "tree.h" | |
6baf1cc8 | 34 | #include "tm_p.h" |
28d81abb | 35 | #include "flags.h" |
6adb4e3a | 36 | #include "except.h" |
28d81abb | 37 | #include "function.h" |
28d81abb | 38 | #include "insn-config.h" |
28d81abb | 39 | #include "expr.h" |
e78d8e51 | 40 | #include "libfuncs.h" |
28d81abb | 41 | #include "hard-reg-set.h" |
28d81abb | 42 | #include "recog.h" |
ca695ac9 | 43 | #include "machmode.h" |
10f0ad3d | 44 | #include "toplev.h" |
d6f4ec51 | 45 | #include "output.h" |
87ff9c8e | 46 | #include "ggc.h" |
43577e6b | 47 | #include "langhooks.h" |
969d70ca | 48 | #include "predict.h" |
9bb231fd | 49 | #include "optabs.h" |
61f71b34 | 50 | #include "target.h" |
66fd46b6 | 51 | #include "regs.h" |
28d81abb RK |
52 | \f |
53 | /* Functions and data structures for expanding case statements. */ | |
54 | ||
55 | /* Case label structure, used to hold info on labels within case | |
56 | statements. We handle "range" labels; for a single-value label | |
57 | as in C, the high and low limits are the same. | |
58 | ||
a6c0a76c SB |
59 | We start with a vector of case nodes sorted in ascending order, and |
60 | the default label as the last element in the vector. Before expanding | |
61 | to RTL, we transform this vector into a list linked via the RIGHT | |
62 | fields in the case_node struct. Nodes with higher case values are | |
63 | later in the list. | |
64 | ||
65 | Switch statements can be output in three forms. A branch table is | |
66 | used if there are more than a few labels and the labels are dense | |
28d81abb RK |
67 | within the range between the smallest and largest case value. If a |
68 | branch table is used, no further manipulations are done with the case | |
69 | node chain. | |
70 | ||
71 | The alternative to the use of a branch table is to generate a series | |
72 | of compare and jump insns. When that is done, we use the LEFT, RIGHT, | |
73 | and PARENT fields to hold a binary tree. Initially the tree is | |
de14fd73 RK |
74 | totally unbalanced, with everything on the right. We balance the tree |
75 | with nodes on the left having lower case values than the parent | |
28d81abb | 76 | and nodes on the right having higher values. We then output the tree |
a6c0a76c SB |
77 | in order. |
78 | ||
79 | For very small, suitable switch statements, we can generate a series | |
80 | of simple bit test and branches instead. */ | |
28d81abb | 81 | |
e2500fed | 82 | struct case_node GTY(()) |
28d81abb RK |
83 | { |
84 | struct case_node *left; /* Left son in binary tree */ | |
85 | struct case_node *right; /* Right son in binary tree; also node chain */ | |
86 | struct case_node *parent; /* Parent of node in binary tree */ | |
87 | tree low; /* Lowest index value for this label */ | |
88 | tree high; /* Highest index value for this label */ | |
89 | tree code_label; /* Label to jump to when node matches */ | |
90 | }; | |
91 | ||
92 | typedef struct case_node case_node; | |
93 | typedef struct case_node *case_node_ptr; | |
94 | ||
95 | /* These are used by estimate_case_costs and balance_case_nodes. */ | |
96 | ||
97 | /* This must be a signed type, and non-ANSI compilers lack signed char. */ | |
e7749837 | 98 | static short cost_table_[129]; |
28d81abb | 99 | static int use_cost_table; |
2a2137c4 RH |
100 | static int cost_table_initialized; |
101 | ||
102 | /* Special care is needed because we allow -1, but TREE_INT_CST_LOW | |
103 | is unsigned. */ | |
cf403648 | 104 | #define COST_TABLE(I) cost_table_[(unsigned HOST_WIDE_INT) ((I) + 1)] |
28d81abb | 105 | \f |
46c5ad27 | 106 | static int n_occurrences (int, const char *); |
46c5ad27 | 107 | static bool decl_conflicts_with_clobbers_p (tree, const HARD_REG_SET); |
46c5ad27 | 108 | static void expand_nl_goto_receiver (void); |
46c5ad27 AJ |
109 | static bool check_operand_nalternatives (tree, tree); |
110 | static bool check_unique_operand_names (tree, tree); | |
111 | static char *resolve_operand_name_1 (char *, tree, tree); | |
ac45df5d | 112 | static void expand_null_return_1 (void); |
46c5ad27 | 113 | static void expand_value_return (rtx); |
46c5ad27 AJ |
114 | static void do_jump_if_equal (rtx, rtx, rtx, int); |
115 | static int estimate_case_costs (case_node_ptr); | |
46c5ad27 AJ |
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); | |
46c5ad27 AJ |
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); | |
46c5ad27 | 123 | static void emit_case_nodes (rtx, case_node_ptr, rtx, tree); |
eb172681 RS |
124 | static struct case_node *add_case_node (struct case_node *, tree, |
125 | tree, tree, tree); | |
0cea056b | 126 | |
28d81abb RK |
127 | \f |
128 | /* Return the rtx-label that corresponds to a LABEL_DECL, | |
129 | creating it if necessary. */ | |
130 | ||
131 | rtx | |
46c5ad27 | 132 | label_rtx (tree label) |
28d81abb | 133 | { |
41374e13 | 134 | gcc_assert (TREE_CODE (label) == LABEL_DECL); |
28d81abb | 135 | |
19e7881c | 136 | if (!DECL_RTL_SET_P (label)) |
6de9cd9a DN |
137 | { |
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; | |
142 | } | |
28d81abb | 143 | |
19e7881c | 144 | return DECL_RTL (label); |
28d81abb RK |
145 | } |
146 | ||
046e4e36 ZW |
147 | /* As above, but also put it on the forced-reference list of the |
148 | function that contains it. */ | |
149 | rtx | |
46c5ad27 | 150 | force_label_rtx (tree label) |
046e4e36 ZW |
151 | { |
152 | rtx ref = label_rtx (label); | |
153 | tree function = decl_function_context (label); | |
154 | struct function *p; | |
155 | ||
41374e13 | 156 | gcc_assert (function); |
046e4e36 | 157 | |
6de9cd9a | 158 | if (function != current_function_decl) |
046e4e36 ZW |
159 | p = find_function_data (function); |
160 | else | |
161 | p = cfun; | |
162 | ||
163 | p->expr->x_forced_labels = gen_rtx_EXPR_LIST (VOIDmode, ref, | |
164 | p->expr->x_forced_labels); | |
165 | return ref; | |
166 | } | |
19e7881c | 167 | |
28d81abb RK |
168 | /* Add an unconditional jump to LABEL as the next sequential instruction. */ |
169 | ||
170 | void | |
46c5ad27 | 171 | emit_jump (rtx label) |
28d81abb RK |
172 | { |
173 | do_pending_stack_adjust (); | |
174 | emit_jump_insn (gen_jump (label)); | |
175 | emit_barrier (); | |
176 | } | |
177 | ||
178 | /* Emit code to jump to the address | |
179 | specified by the pointer expression EXP. */ | |
180 | ||
181 | void | |
46c5ad27 | 182 | expand_computed_goto (tree exp) |
28d81abb | 183 | { |
b93a436e | 184 | rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0); |
ed9a9db1 | 185 | |
5ae6cd0d | 186 | x = convert_memory_address (Pmode, x); |
ffa1a1ce | 187 | |
eb4e1c01 JH |
188 | do_pending_stack_adjust (); |
189 | emit_indirect_jump (x); | |
28d81abb RK |
190 | } |
191 | \f | |
192 | /* Handle goto statements and the labels that they can go to. */ | |
193 | ||
194 | /* Specify the location in the RTL code of a label LABEL, | |
195 | which is a LABEL_DECL tree node. | |
196 | ||
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. | |
201 | ||
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. */ | |
204 | ||
205 | void | |
46c5ad27 | 206 | expand_label (tree label) |
28d81abb | 207 | { |
6de9cd9a | 208 | rtx label_r = label_rtx (label); |
28d81abb RK |
209 | |
210 | do_pending_stack_adjust (); | |
6de9cd9a | 211 | emit_label (label_r); |
28d81abb RK |
212 | if (DECL_NAME (label)) |
213 | LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label)); | |
214 | ||
6de9cd9a DN |
215 | if (DECL_NONLOCAL (label)) |
216 | { | |
217 | expand_nl_goto_receiver (); | |
218 | nonlocal_goto_handler_labels | |
219 | = gen_rtx_EXPR_LIST (VOIDmode, label_r, | |
220 | nonlocal_goto_handler_labels); | |
221 | } | |
222 | ||
223 | if (FORCED_LABEL (label)) | |
224 | forced_labels = gen_rtx_EXPR_LIST (VOIDmode, label_r, forced_labels); | |
caf93cb0 | 225 | |
6de9cd9a DN |
226 | if (DECL_NONLOCAL (label) || FORCED_LABEL (label)) |
227 | maybe_set_first_label_num (label_r); | |
28d81abb RK |
228 | } |
229 | ||
28d81abb RK |
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'. */ | |
233 | ||
234 | void | |
46c5ad27 | 235 | expand_goto (tree label) |
28d81abb | 236 | { |
6de9cd9a DN |
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); | |
41374e13 | 241 | gcc_assert (!context || context == current_function_decl); |
28d81abb | 242 | #endif |
4b01bd16 | 243 | |
ac45df5d | 244 | emit_jump (label_rtx (label)); |
28d81abb | 245 | } |
2a230e9d BS |
246 | \f |
247 | /* Return the number of times character C occurs in string S. */ | |
248 | static int | |
46c5ad27 | 249 | n_occurrences (int c, const char *s) |
2a230e9d BS |
250 | { |
251 | int n = 0; | |
252 | while (*s) | |
253 | n += (*s++ == c); | |
254 | return n; | |
255 | } | |
28d81abb RK |
256 | \f |
257 | /* Generate RTL for an asm statement (explicit assembler code). | |
4c46ea23 EB |
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. */ | |
28d81abb | 261 | |
bac6bfc5 | 262 | static void |
46c5ad27 | 263 | expand_asm (tree string, int vol) |
28d81abb | 264 | { |
4c46ea23 EB |
265 | rtx body; |
266 | ||
267 | if (TREE_CODE (string) == ADDR_EXPR) | |
268 | string = TREE_OPERAND (string, 0); | |
269 | ||
a396f8ae GK |
270 | body = gen_rtx_ASM_INPUT (VOIDmode, |
271 | ggc_strdup (TREE_STRING_POINTER (string))); | |
4c46ea23 EB |
272 | |
273 | MEM_VOLATILE_P (body) = vol; | |
28d81abb | 274 | |
4c46ea23 | 275 | emit_insn (body); |
28d81abb RK |
276 | } |
277 | ||
40b18c0a MM |
278 | /* Parse the output constraint pointed to by *CONSTRAINT_P. It is the |
279 | OPERAND_NUMth output operand, indexed from zero. There are NINPUTS | |
280 | inputs and NOUTPUTS outputs to this extended-asm. Upon return, | |
281 | *ALLOWS_MEM will be TRUE iff the constraint allows the use of a | |
282 | memory operand. Similarly, *ALLOWS_REG will be TRUE iff the | |
283 | constraint allows the use of a register operand. And, *IS_INOUT | |
284 | will be true if the operand is read-write, i.e., if it is used as | |
285 | an input as well as an output. If *CONSTRAINT_P is not in | |
286 | canonical form, it will be made canonical. (Note that `+' will be | |
14b493d6 | 287 | replaced with `=' as part of this process.) |
40b18c0a MM |
288 | |
289 | Returns TRUE if all went well; FALSE if an error occurred. */ | |
290 | ||
291 | bool | |
46c5ad27 AJ |
292 | parse_output_constraint (const char **constraint_p, int operand_num, |
293 | int ninputs, int noutputs, bool *allows_mem, | |
294 | bool *allows_reg, bool *is_inout) | |
40b18c0a MM |
295 | { |
296 | const char *constraint = *constraint_p; | |
297 | const char *p; | |
298 | ||
299 | /* Assume the constraint doesn't allow the use of either a register | |
300 | or memory. */ | |
301 | *allows_mem = false; | |
302 | *allows_reg = false; | |
303 | ||
304 | /* Allow the `=' or `+' to not be at the beginning of the string, | |
305 | since it wasn't explicitly documented that way, and there is a | |
306 | large body of code that puts it last. Swap the character to | |
307 | the front, so as not to uglify any place else. */ | |
308 | p = strchr (constraint, '='); | |
309 | if (!p) | |
310 | p = strchr (constraint, '+'); | |
311 | ||
312 | /* If the string doesn't contain an `=', issue an error | |
313 | message. */ | |
314 | if (!p) | |
315 | { | |
971801ff | 316 | error ("output operand constraint lacks %<=%>"); |
40b18c0a MM |
317 | return false; |
318 | } | |
319 | ||
320 | /* If the constraint begins with `+', then the operand is both read | |
321 | from and written to. */ | |
322 | *is_inout = (*p == '+'); | |
323 | ||
40b18c0a MM |
324 | /* Canonicalize the output constraint so that it begins with `='. */ |
325 | if (p != constraint || is_inout) | |
326 | { | |
327 | char *buf; | |
328 | size_t c_len = strlen (constraint); | |
329 | ||
330 | if (p != constraint) | |
971801ff JM |
331 | warning ("output constraint %qc for operand %d " |
332 | "is not at the beginning", | |
40b18c0a MM |
333 | *p, operand_num); |
334 | ||
335 | /* Make a copy of the constraint. */ | |
336 | buf = alloca (c_len + 1); | |
337 | strcpy (buf, constraint); | |
338 | /* Swap the first character and the `=' or `+'. */ | |
339 | buf[p - constraint] = buf[0]; | |
340 | /* Make sure the first character is an `='. (Until we do this, | |
341 | it might be a `+'.) */ | |
342 | buf[0] = '='; | |
343 | /* Replace the constraint with the canonicalized string. */ | |
344 | *constraint_p = ggc_alloc_string (buf, c_len); | |
345 | constraint = *constraint_p; | |
346 | } | |
347 | ||
348 | /* Loop through the constraint string. */ | |
97488870 | 349 | for (p = constraint + 1; *p; p += CONSTRAINT_LEN (*p, p)) |
40b18c0a MM |
350 | switch (*p) |
351 | { | |
352 | case '+': | |
353 | case '=': | |
971801ff JM |
354 | error ("operand constraint contains incorrectly positioned " |
355 | "%<+%> or %<=%>"); | |
40b18c0a | 356 | return false; |
786de7eb | 357 | |
40b18c0a MM |
358 | case '%': |
359 | if (operand_num + 1 == ninputs + noutputs) | |
360 | { | |
971801ff | 361 | error ("%<%%%> constraint used with last operand"); |
40b18c0a MM |
362 | return false; |
363 | } | |
364 | break; | |
365 | ||
366 | case 'V': case 'm': case 'o': | |
367 | *allows_mem = true; | |
368 | break; | |
369 | ||
370 | case '?': case '!': case '*': case '&': case '#': | |
371 | case 'E': case 'F': case 'G': case 'H': | |
372 | case 's': case 'i': case 'n': | |
373 | case 'I': case 'J': case 'K': case 'L': case 'M': | |
374 | case 'N': case 'O': case 'P': case ',': | |
375 | break; | |
376 | ||
377 | case '0': case '1': case '2': case '3': case '4': | |
378 | case '5': case '6': case '7': case '8': case '9': | |
84b72302 | 379 | case '[': |
40b18c0a MM |
380 | error ("matching constraint not valid in output operand"); |
381 | return false; | |
382 | ||
383 | case '<': case '>': | |
384 | /* ??? Before flow, auto inc/dec insns are not supposed to exist, | |
385 | excepting those that expand_call created. So match memory | |
386 | and hope. */ | |
387 | *allows_mem = true; | |
388 | break; | |
389 | ||
390 | case 'g': case 'X': | |
391 | *allows_reg = true; | |
392 | *allows_mem = true; | |
393 | break; | |
786de7eb | 394 | |
40b18c0a MM |
395 | case 'p': case 'r': |
396 | *allows_reg = true; | |
397 | break; | |
398 | ||
399 | default: | |
400 | if (!ISALPHA (*p)) | |
401 | break; | |
97488870 | 402 | if (REG_CLASS_FROM_CONSTRAINT (*p, p) != NO_REGS) |
40b18c0a | 403 | *allows_reg = true; |
97488870 R |
404 | #ifdef EXTRA_CONSTRAINT_STR |
405 | else if (EXTRA_ADDRESS_CONSTRAINT (*p, p)) | |
ccfc6cc8 | 406 | *allows_reg = true; |
97488870 | 407 | else if (EXTRA_MEMORY_CONSTRAINT (*p, p)) |
ccfc6cc8 | 408 | *allows_mem = true; |
40b18c0a MM |
409 | else |
410 | { | |
411 | /* Otherwise we can't assume anything about the nature of | |
412 | the constraint except that it isn't purely registers. | |
413 | Treat it like "g" and hope for the best. */ | |
414 | *allows_reg = true; | |
415 | *allows_mem = true; | |
416 | } | |
417 | #endif | |
418 | break; | |
419 | } | |
420 | ||
421 | return true; | |
422 | } | |
423 | ||
6be2e1f8 RH |
424 | /* Similar, but for input constraints. */ |
425 | ||
1456deaf | 426 | bool |
46c5ad27 AJ |
427 | parse_input_constraint (const char **constraint_p, int input_num, |
428 | int ninputs, int noutputs, int ninout, | |
429 | const char * const * constraints, | |
430 | bool *allows_mem, bool *allows_reg) | |
6be2e1f8 RH |
431 | { |
432 | const char *constraint = *constraint_p; | |
433 | const char *orig_constraint = constraint; | |
434 | size_t c_len = strlen (constraint); | |
435 | size_t j; | |
f3da0ead | 436 | bool saw_match = false; |
6be2e1f8 RH |
437 | |
438 | /* Assume the constraint doesn't allow the use of either | |
439 | a register or memory. */ | |
440 | *allows_mem = false; | |
441 | *allows_reg = false; | |
442 | ||
443 | /* Make sure constraint has neither `=', `+', nor '&'. */ | |
444 | ||
97488870 | 445 | for (j = 0; j < c_len; j += CONSTRAINT_LEN (constraint[j], constraint+j)) |
6be2e1f8 RH |
446 | switch (constraint[j]) |
447 | { | |
448 | case '+': case '=': case '&': | |
449 | if (constraint == orig_constraint) | |
450 | { | |
971801ff | 451 | error ("input operand constraint contains %qc", constraint[j]); |
6be2e1f8 RH |
452 | return false; |
453 | } | |
454 | break; | |
455 | ||
456 | case '%': | |
457 | if (constraint == orig_constraint | |
458 | && input_num + 1 == ninputs - ninout) | |
459 | { | |
971801ff | 460 | error ("%<%%%> constraint used with last operand"); |
6be2e1f8 RH |
461 | return false; |
462 | } | |
463 | break; | |
464 | ||
465 | case 'V': case 'm': case 'o': | |
466 | *allows_mem = true; | |
467 | break; | |
468 | ||
469 | case '<': case '>': | |
470 | case '?': case '!': case '*': case '#': | |
471 | case 'E': case 'F': case 'G': case 'H': | |
472 | case 's': case 'i': case 'n': | |
473 | case 'I': case 'J': case 'K': case 'L': case 'M': | |
474 | case 'N': case 'O': case 'P': case ',': | |
475 | break; | |
476 | ||
477 | /* Whether or not a numeric constraint allows a register is | |
478 | decided by the matching constraint, and so there is no need | |
479 | to do anything special with them. We must handle them in | |
480 | the default case, so that we don't unnecessarily force | |
481 | operands to memory. */ | |
482 | case '0': case '1': case '2': case '3': case '4': | |
483 | case '5': case '6': case '7': case '8': case '9': | |
484 | { | |
485 | char *end; | |
486 | unsigned long match; | |
487 | ||
f3da0ead JM |
488 | saw_match = true; |
489 | ||
6be2e1f8 RH |
490 | match = strtoul (constraint + j, &end, 10); |
491 | if (match >= (unsigned long) noutputs) | |
492 | { | |
493 | error ("matching constraint references invalid operand number"); | |
494 | return false; | |
495 | } | |
496 | ||
497 | /* Try and find the real constraint for this dup. Only do this | |
498 | if the matching constraint is the only alternative. */ | |
499 | if (*end == '\0' | |
500 | && (j == 0 || (j == 1 && constraint[0] == '%'))) | |
501 | { | |
502 | constraint = constraints[match]; | |
503 | *constraint_p = constraint; | |
504 | c_len = strlen (constraint); | |
505 | j = 0; | |
97488870 R |
506 | /* ??? At the end of the loop, we will skip the first part of |
507 | the matched constraint. This assumes not only that the | |
508 | other constraint is an output constraint, but also that | |
509 | the '=' or '+' come first. */ | |
6be2e1f8 RH |
510 | break; |
511 | } | |
512 | else | |
513 | j = end - constraint; | |
97488870 R |
514 | /* Anticipate increment at end of loop. */ |
515 | j--; | |
6be2e1f8 RH |
516 | } |
517 | /* Fall through. */ | |
518 | ||
519 | case 'p': case 'r': | |
520 | *allows_reg = true; | |
521 | break; | |
522 | ||
523 | case 'g': case 'X': | |
524 | *allows_reg = true; | |
525 | *allows_mem = true; | |
526 | break; | |
527 | ||
528 | default: | |
529 | if (! ISALPHA (constraint[j])) | |
530 | { | |
971801ff | 531 | error ("invalid punctuation %qc in constraint", constraint[j]); |
6be2e1f8 RH |
532 | return false; |
533 | } | |
97488870 R |
534 | if (REG_CLASS_FROM_CONSTRAINT (constraint[j], constraint + j) |
535 | != NO_REGS) | |
6be2e1f8 | 536 | *allows_reg = true; |
97488870 R |
537 | #ifdef EXTRA_CONSTRAINT_STR |
538 | else if (EXTRA_ADDRESS_CONSTRAINT (constraint[j], constraint + j)) | |
ccfc6cc8 | 539 | *allows_reg = true; |
97488870 | 540 | else if (EXTRA_MEMORY_CONSTRAINT (constraint[j], constraint + j)) |
ccfc6cc8 | 541 | *allows_mem = true; |
6be2e1f8 RH |
542 | else |
543 | { | |
544 | /* Otherwise we can't assume anything about the nature of | |
545 | the constraint except that it isn't purely registers. | |
546 | Treat it like "g" and hope for the best. */ | |
547 | *allows_reg = true; | |
548 | *allows_mem = true; | |
549 | } | |
550 | #endif | |
551 | break; | |
552 | } | |
553 | ||
f3da0ead JM |
554 | if (saw_match && !*allows_reg) |
555 | warning ("matching constraint does not allow a register"); | |
556 | ||
6be2e1f8 RH |
557 | return true; |
558 | } | |
559 | ||
acb5d088 HPN |
560 | /* Check for overlap between registers marked in CLOBBERED_REGS and |
561 | anything inappropriate in DECL. Emit error and return TRUE for error, | |
562 | FALSE for ok. */ | |
563 | ||
564 | static bool | |
46c5ad27 | 565 | decl_conflicts_with_clobbers_p (tree decl, const HARD_REG_SET clobbered_regs) |
acb5d088 HPN |
566 | { |
567 | /* Conflicts between asm-declared register variables and the clobber | |
568 | list are not allowed. */ | |
569 | if ((TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == PARM_DECL) | |
570 | && DECL_REGISTER (decl) | |
34146b94 | 571 | && REG_P (DECL_RTL (decl)) |
acb5d088 HPN |
572 | && REGNO (DECL_RTL (decl)) < FIRST_PSEUDO_REGISTER) |
573 | { | |
574 | rtx reg = DECL_RTL (decl); | |
575 | unsigned int regno; | |
576 | ||
577 | for (regno = REGNO (reg); | |
578 | regno < (REGNO (reg) | |
66fd46b6 | 579 | + hard_regno_nregs[REGNO (reg)][GET_MODE (reg)]); |
acb5d088 HPN |
580 | regno++) |
581 | if (TEST_HARD_REG_BIT (clobbered_regs, regno)) | |
582 | { | |
971801ff JM |
583 | error ("asm-specifier for variable %qs conflicts with " |
584 | "asm clobber list", | |
acb5d088 HPN |
585 | IDENTIFIER_POINTER (DECL_NAME (decl))); |
586 | ||
587 | /* Reset registerness to stop multiple errors emitted for a | |
588 | single variable. */ | |
589 | DECL_REGISTER (decl) = 0; | |
590 | return true; | |
591 | } | |
592 | } | |
593 | return false; | |
594 | } | |
595 | ||
28d81abb RK |
596 | /* Generate RTL for an asm statement with arguments. |
597 | STRING is the instruction template. | |
598 | OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs. | |
599 | Each output or input has an expression in the TREE_VALUE and | |
2ec37136 | 600 | and a tree list in TREE_PURPOSE which in turn contains a constraint |
786de7eb | 601 | name in TREE_VALUE (or NULL_TREE) and a constraint string |
2ec37136 | 602 | in TREE_PURPOSE. |
28d81abb RK |
603 | CLOBBERS is a list of STRING_CST nodes each naming a hard register |
604 | that is clobbered by this insn. | |
605 | ||
606 | Not all kinds of lvalue that may appear in OUTPUTS can be stored directly. | |
607 | Some elements of OUTPUTS may be replaced with trees representing temporary | |
608 | values. The caller should copy those temporary values to the originally | |
609 | specified lvalues. | |
610 | ||
611 | VOL nonzero means the insn is volatile; don't optimize it. */ | |
612 | ||
bac6bfc5 | 613 | static void |
46c5ad27 | 614 | expand_asm_operands (tree string, tree outputs, tree inputs, |
177560b2 | 615 | tree clobbers, int vol, location_t locus) |
28d81abb | 616 | { |
84b72302 | 617 | rtvec argvec, constraintvec; |
28d81abb RK |
618 | rtx body; |
619 | int ninputs = list_length (inputs); | |
620 | int noutputs = list_length (outputs); | |
6be2e1f8 | 621 | int ninout; |
b4ccaa16 | 622 | int nclobbers; |
acb5d088 HPN |
623 | HARD_REG_SET clobbered_regs; |
624 | int clobber_conflict_found = 0; | |
28d81abb | 625 | tree tail; |
7dc8b126 | 626 | tree t; |
b3694847 | 627 | int i; |
28d81abb | 628 | /* Vector of RTX's of evaluated output operands. */ |
703ad42b KG |
629 | rtx *output_rtx = alloca (noutputs * sizeof (rtx)); |
630 | int *inout_opnum = alloca (noutputs * sizeof (int)); | |
631 | rtx *real_output_rtx = alloca (noutputs * sizeof (rtx)); | |
235c5021 | 632 | enum machine_mode *inout_mode |
703ad42b | 633 | = alloca (noutputs * sizeof (enum machine_mode)); |
84b72302 | 634 | const char **constraints |
703ad42b | 635 | = alloca ((noutputs + ninputs) * sizeof (const char *)); |
1b3d8f8a | 636 | int old_generating_concat_p = generating_concat_p; |
28d81abb | 637 | |
e5e809f4 | 638 | /* An ASM with no outputs needs to be treated as volatile, for now. */ |
296f8acc JL |
639 | if (noutputs == 0) |
640 | vol = 1; | |
641 | ||
84b72302 RH |
642 | if (! check_operand_nalternatives (outputs, inputs)) |
643 | return; | |
644 | ||
7dc8b126 JM |
645 | string = resolve_asm_operand_names (string, outputs, inputs); |
646 | ||
647 | /* Collect constraints. */ | |
648 | i = 0; | |
649 | for (t = outputs; t ; t = TREE_CHAIN (t), i++) | |
650 | constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t))); | |
651 | for (t = inputs; t ; t = TREE_CHAIN (t), i++) | |
652 | constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t))); | |
84b72302 | 653 | |
57bcb97a RH |
654 | /* Sometimes we wish to automatically clobber registers across an asm. |
655 | Case in point is when the i386 backend moved from cc0 to a hard reg -- | |
f63d1bf7 | 656 | maintaining source-level compatibility means automatically clobbering |
57bcb97a | 657 | the flags register. */ |
67dfe110 | 658 | clobbers = targetm.md_asm_clobbers (clobbers); |
57bcb97a | 659 | |
b4ccaa16 RS |
660 | /* Count the number of meaningful clobbered registers, ignoring what |
661 | we would ignore later. */ | |
662 | nclobbers = 0; | |
acb5d088 | 663 | CLEAR_HARD_REG_SET (clobbered_regs); |
b4ccaa16 RS |
664 | for (tail = clobbers; tail; tail = TREE_CHAIN (tail)) |
665 | { | |
47ee9bcb | 666 | const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail)); |
14a774a9 | 667 | |
c09e6498 RS |
668 | i = decode_reg_name (regname); |
669 | if (i >= 0 || i == -4) | |
b4ccaa16 | 670 | ++nclobbers; |
7859e3ac | 671 | else if (i == -2) |
971801ff | 672 | error ("unknown register name %qs in %<asm%>", regname); |
acb5d088 HPN |
673 | |
674 | /* Mark clobbered registers. */ | |
675 | if (i >= 0) | |
e54b4cae | 676 | { |
ea4b7848 | 677 | /* Clobbering the PIC register is an error. */ |
fc555370 | 678 | if (i == (int) PIC_OFFSET_TABLE_REGNUM) |
e54b4cae | 679 | { |
971801ff | 680 | error ("PIC register %qs clobbered in %<asm%>", regname); |
e54b4cae EB |
681 | return; |
682 | } | |
683 | ||
684 | SET_HARD_REG_BIT (clobbered_regs, i); | |
685 | } | |
b4ccaa16 RS |
686 | } |
687 | ||
6be2e1f8 RH |
688 | /* First pass over inputs and outputs checks validity and sets |
689 | mark_addressable if needed. */ | |
690 | ||
691 | ninout = 0; | |
28d81abb RK |
692 | for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) |
693 | { | |
694 | tree val = TREE_VALUE (tail); | |
b50a024d | 695 | tree type = TREE_TYPE (val); |
6be2e1f8 | 696 | const char *constraint; |
40b18c0a MM |
697 | bool is_inout; |
698 | bool allows_reg; | |
699 | bool allows_mem; | |
28d81abb RK |
700 | |
701 | /* If there's an erroneous arg, emit no insn. */ | |
40b18c0a | 702 | if (type == error_mark_node) |
28d81abb RK |
703 | return; |
704 | ||
40b18c0a MM |
705 | /* Try to parse the output constraint. If that fails, there's |
706 | no point in going further. */ | |
6be2e1f8 RH |
707 | constraint = constraints[i]; |
708 | if (!parse_output_constraint (&constraint, i, ninputs, noutputs, | |
709 | &allows_mem, &allows_reg, &is_inout)) | |
710 | return; | |
711 | ||
712 | if (! allows_reg | |
713 | && (allows_mem | |
714 | || is_inout | |
715 | || (DECL_P (val) | |
f8cfc6aa | 716 | && REG_P (DECL_RTL (val)) |
6be2e1f8 | 717 | && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))) |
ae2bcd98 | 718 | lang_hooks.mark_addressable (val); |
6be2e1f8 RH |
719 | |
720 | if (is_inout) | |
721 | ninout++; | |
722 | } | |
723 | ||
724 | ninputs += ninout; | |
725 | if (ninputs + noutputs > MAX_RECOG_OPERANDS) | |
726 | { | |
971801ff | 727 | error ("more than %d operands in %<asm%>", MAX_RECOG_OPERANDS); |
6be2e1f8 RH |
728 | return; |
729 | } | |
730 | ||
731 | for (i = 0, tail = inputs; tail; i++, tail = TREE_CHAIN (tail)) | |
732 | { | |
733 | bool allows_reg, allows_mem; | |
734 | const char *constraint; | |
735 | ||
736 | /* If there's an erroneous arg, emit no insn, because the ASM_INPUT | |
737 | would get VOIDmode and that could cause a crash in reload. */ | |
738 | if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node) | |
739 | return; | |
740 | ||
741 | constraint = constraints[i + noutputs]; | |
742 | if (! parse_input_constraint (&constraint, i, ninputs, noutputs, ninout, | |
743 | constraints, &allows_mem, &allows_reg)) | |
40b18c0a | 744 | return; |
d09a75ae | 745 | |
6be2e1f8 | 746 | if (! allows_reg && allows_mem) |
ae2bcd98 | 747 | lang_hooks.mark_addressable (TREE_VALUE (tail)); |
6be2e1f8 RH |
748 | } |
749 | ||
750 | /* Second pass evaluates arguments. */ | |
751 | ||
752 | ninout = 0; | |
753 | for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) | |
754 | { | |
755 | tree val = TREE_VALUE (tail); | |
756 | tree type = TREE_TYPE (val); | |
757 | bool is_inout; | |
758 | bool allows_reg; | |
759 | bool allows_mem; | |
5b50aa9d | 760 | rtx op; |
41374e13 | 761 | bool ok; |
6be2e1f8 | 762 | |
41374e13 | 763 | ok = parse_output_constraint (&constraints[i], i, ninputs, |
6be2e1f8 | 764 | noutputs, &allows_mem, &allows_reg, |
41374e13 NS |
765 | &is_inout); |
766 | gcc_assert (ok); | |
6be2e1f8 | 767 | |
d09a75ae RK |
768 | /* If an output operand is not a decl or indirect ref and our constraint |
769 | allows a register, make a temporary to act as an intermediate. | |
770 | Make the asm insn write into that, then our caller will copy it to | |
771 | the real output operand. Likewise for promoted variables. */ | |
28d81abb | 772 | |
1b3d8f8a GK |
773 | generating_concat_p = 0; |
774 | ||
947255ed | 775 | real_output_rtx[i] = NULL_RTX; |
1afbe1c4 RH |
776 | if ((TREE_CODE (val) == INDIRECT_REF |
777 | && allows_mem) | |
2f939d94 | 778 | || (DECL_P (val) |
f8cfc6aa JQ |
779 | && (allows_mem || REG_P (DECL_RTL (val))) |
780 | && ! (REG_P (DECL_RTL (val)) | |
d09a75ae | 781 | && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type))) |
11579f33 | 782 | || ! allows_reg |
2a230e9d | 783 | || is_inout) |
d09a75ae | 784 | { |
5b50aa9d | 785 | op = expand_expr (val, NULL_RTX, VOIDmode, EXPAND_WRITE); |
3c0cb5de | 786 | if (MEM_P (op)) |
5b50aa9d | 787 | op = validize_mem (op); |
d09a75ae | 788 | |
3c0cb5de | 789 | if (! allows_reg && !MEM_P (op)) |
d09a75ae | 790 | error ("output number %d not directly addressable", i); |
3c0cb5de | 791 | if ((! allows_mem && MEM_P (op)) |
5b50aa9d | 792 | || GET_CODE (op) == CONCAT) |
947255ed | 793 | { |
ad76cef8 | 794 | real_output_rtx[i] = op; |
5b50aa9d | 795 | op = gen_reg_rtx (GET_MODE (op)); |
11579f33 | 796 | if (is_inout) |
5b50aa9d | 797 | emit_move_insn (op, real_output_rtx[i]); |
947255ed | 798 | } |
d09a75ae | 799 | } |
b50a024d | 800 | else |
e619bb8d | 801 | { |
5b50aa9d RH |
802 | op = assign_temp (type, 0, 0, 1); |
803 | op = validize_mem (op); | |
804 | TREE_VALUE (tail) = make_tree (type, op); | |
b50a024d | 805 | } |
5b50aa9d | 806 | output_rtx[i] = op; |
235c5021 | 807 | |
1b3d8f8a GK |
808 | generating_concat_p = old_generating_concat_p; |
809 | ||
2a230e9d | 810 | if (is_inout) |
235c5021 | 811 | { |
6be2e1f8 | 812 | inout_mode[ninout] = TYPE_MODE (type); |
235c5021 RK |
813 | inout_opnum[ninout++] = i; |
814 | } | |
acb5d088 HPN |
815 | |
816 | if (decl_conflicts_with_clobbers_p (val, clobbered_regs)) | |
817 | clobber_conflict_found = 1; | |
28d81abb RK |
818 | } |
819 | ||
84b72302 RH |
820 | /* Make vectors for the expression-rtx, constraint strings, |
821 | and named operands. */ | |
28d81abb RK |
822 | |
823 | argvec = rtvec_alloc (ninputs); | |
84b72302 | 824 | constraintvec = rtvec_alloc (ninputs); |
28d81abb | 825 | |
6462bb43 AO |
826 | body = gen_rtx_ASM_OPERANDS ((noutputs == 0 ? VOIDmode |
827 | : GET_MODE (output_rtx[0])), | |
a396f8ae | 828 | ggc_strdup (TREE_STRING_POINTER (string)), |
84b72302 | 829 | empty_string, 0, argvec, constraintvec, |
6773e15f | 830 | locus); |
c85f7c16 | 831 | |
78418280 | 832 | MEM_VOLATILE_P (body) = vol; |
28d81abb RK |
833 | |
834 | /* Eval the inputs and put them into ARGVEC. | |
835 | Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */ | |
836 | ||
84b72302 | 837 | for (i = 0, tail = inputs; tail; tail = TREE_CHAIN (tail), ++i) |
28d81abb | 838 | { |
6be2e1f8 RH |
839 | bool allows_reg, allows_mem; |
840 | const char *constraint; | |
841 | tree val, type; | |
1f06ee8d | 842 | rtx op; |
41374e13 | 843 | bool ok; |
28d81abb | 844 | |
6be2e1f8 | 845 | constraint = constraints[i + noutputs]; |
41374e13 NS |
846 | ok = parse_input_constraint (&constraint, i, ninputs, noutputs, ninout, |
847 | constraints, &allows_mem, &allows_reg); | |
848 | gcc_assert (ok); | |
2a230e9d | 849 | |
6be2e1f8 | 850 | generating_concat_p = 0; |
65fed0cb | 851 | |
6be2e1f8 RH |
852 | val = TREE_VALUE (tail); |
853 | type = TREE_TYPE (val); | |
017e1b43 RH |
854 | op = expand_expr (val, NULL_RTX, VOIDmode, |
855 | (allows_mem && !allows_reg | |
856 | ? EXPAND_MEMORY : EXPAND_NORMAL)); | |
65fed0cb | 857 | |
1b3d8f8a | 858 | /* Never pass a CONCAT to an ASM. */ |
1b3d8f8a GK |
859 | if (GET_CODE (op) == CONCAT) |
860 | op = force_reg (GET_MODE (op), op); | |
3c0cb5de | 861 | else if (MEM_P (op)) |
5b50aa9d | 862 | op = validize_mem (op); |
1b3d8f8a | 863 | |
1afbe1c4 | 864 | if (asm_operand_ok (op, constraint) <= 0) |
65fed0cb | 865 | { |
11579f33 | 866 | if (allows_reg) |
6be2e1f8 | 867 | op = force_reg (TYPE_MODE (type), op); |
11579f33 | 868 | else if (!allows_mem) |
971801ff | 869 | warning ("asm operand %d probably doesn%'t match constraints", |
84b72302 | 870 | i + noutputs); |
3c0cb5de | 871 | else if (MEM_P (op)) |
6be2e1f8 | 872 | { |
d50ad6af RH |
873 | /* We won't recognize either volatile memory or memory |
874 | with a queued address as available a memory_operand | |
875 | at this point. Ignore it: clearly this *is* a memory. */ | |
6be2e1f8 | 876 | } |
1f06ee8d | 877 | else |
017e1b43 | 878 | { |
71ed1fdb RH |
879 | warning ("use of memory input without lvalue in " |
880 | "asm operand %d is deprecated", i + noutputs); | |
017e1b43 RH |
881 | |
882 | if (CONSTANT_P (op)) | |
883 | { | |
9c858681 RS |
884 | rtx mem = force_const_mem (TYPE_MODE (type), op); |
885 | if (mem) | |
886 | op = validize_mem (mem); | |
887 | else | |
888 | op = force_reg (TYPE_MODE (type), op); | |
017e1b43 | 889 | } |
f8cfc6aa | 890 | if (REG_P (op) |
9c858681 | 891 | || GET_CODE (op) == SUBREG |
9c858681 | 892 | || GET_CODE (op) == CONCAT) |
017e1b43 RH |
893 | { |
894 | tree qual_type = build_qualified_type (type, | |
895 | (TYPE_QUALS (type) | |
896 | | TYPE_QUAL_CONST)); | |
897 | rtx memloc = assign_temp (qual_type, 1, 1, 1); | |
898 | memloc = validize_mem (memloc); | |
899 | emit_move_insn (memloc, op); | |
900 | op = memloc; | |
901 | } | |
902 | } | |
65fed0cb | 903 | } |
6be2e1f8 | 904 | |
1b3d8f8a | 905 | generating_concat_p = old_generating_concat_p; |
6462bb43 | 906 | ASM_OPERANDS_INPUT (body, i) = op; |
2a230e9d | 907 | |
6462bb43 | 908 | ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, i) |
a396f8ae GK |
909 | = gen_rtx_ASM_INPUT (TYPE_MODE (type), |
910 | ggc_strdup (constraints[i + noutputs])); | |
acb5d088 HPN |
911 | |
912 | if (decl_conflicts_with_clobbers_p (val, clobbered_regs)) | |
913 | clobber_conflict_found = 1; | |
28d81abb RK |
914 | } |
915 | ||
14a774a9 RK |
916 | /* Protect all the operands from the queue now that they have all been |
917 | evaluated. */ | |
28d81abb | 918 | |
1b3d8f8a GK |
919 | generating_concat_p = 0; |
920 | ||
4381f7c2 | 921 | /* For in-out operands, copy output rtx to input rtx. */ |
235c5021 RK |
922 | for (i = 0; i < ninout; i++) |
923 | { | |
235c5021 | 924 | int j = inout_opnum[i]; |
84b72302 | 925 | char buffer[16]; |
235c5021 | 926 | |
6462bb43 | 927 | ASM_OPERANDS_INPUT (body, ninputs - ninout + i) |
235c5021 | 928 | = output_rtx[j]; |
84b72302 RH |
929 | |
930 | sprintf (buffer, "%d", j); | |
6462bb43 | 931 | ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, ninputs - ninout + i) |
485bad26 | 932 | = gen_rtx_ASM_INPUT (inout_mode[i], ggc_strdup (buffer)); |
235c5021 RK |
933 | } |
934 | ||
1b3d8f8a GK |
935 | generating_concat_p = old_generating_concat_p; |
936 | ||
28d81abb | 937 | /* Now, for each output, construct an rtx |
84b72302 RH |
938 | (set OUTPUT (asm_operands INSN OUTPUTCONSTRAINT OUTPUTNUMBER |
939 | ARGVEC CONSTRAINTS OPNAMES)) | |
28d81abb RK |
940 | If there is more than one, put them inside a PARALLEL. */ |
941 | ||
942 | if (noutputs == 1 && nclobbers == 0) | |
943 | { | |
a396f8ae | 944 | ASM_OPERANDS_OUTPUT_CONSTRAINT (body) = ggc_strdup (constraints[0]); |
4977bab6 | 945 | emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body)); |
28d81abb | 946 | } |
14a774a9 | 947 | |
28d81abb RK |
948 | else if (noutputs == 0 && nclobbers == 0) |
949 | { | |
950 | /* No output operands: put in a raw ASM_OPERANDS rtx. */ | |
4977bab6 | 951 | emit_insn (body); |
28d81abb | 952 | } |
14a774a9 | 953 | |
28d81abb RK |
954 | else |
955 | { | |
956 | rtx obody = body; | |
957 | int num = noutputs; | |
14a774a9 RK |
958 | |
959 | if (num == 0) | |
960 | num = 1; | |
961 | ||
38a448ca | 962 | body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers)); |
28d81abb RK |
963 | |
964 | /* For each output operand, store a SET. */ | |
28d81abb RK |
965 | for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) |
966 | { | |
967 | XVECEXP (body, 0, i) | |
38a448ca RH |
968 | = gen_rtx_SET (VOIDmode, |
969 | output_rtx[i], | |
c5c76735 | 970 | gen_rtx_ASM_OPERANDS |
6462bb43 | 971 | (GET_MODE (output_rtx[i]), |
a396f8ae GK |
972 | ggc_strdup (TREE_STRING_POINTER (string)), |
973 | ggc_strdup (constraints[i]), | |
974 | i, argvec, constraintvec, locus)); | |
c5c76735 | 975 | |
28d81abb RK |
976 | MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol; |
977 | } | |
978 | ||
979 | /* If there are no outputs (but there are some clobbers) | |
980 | store the bare ASM_OPERANDS into the PARALLEL. */ | |
981 | ||
982 | if (i == 0) | |
983 | XVECEXP (body, 0, i++) = obody; | |
984 | ||
985 | /* Store (clobber REG) for each clobbered register specified. */ | |
986 | ||
b4ccaa16 | 987 | for (tail = clobbers; tail; tail = TREE_CHAIN (tail)) |
28d81abb | 988 | { |
47ee9bcb | 989 | const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail)); |
b4ac57ab | 990 | int j = decode_reg_name (regname); |
acb5d088 | 991 | rtx clobbered_reg; |
28d81abb | 992 | |
b4ac57ab | 993 | if (j < 0) |
28d81abb | 994 | { |
c09e6498 | 995 | if (j == -3) /* `cc', which is not a register */ |
dcfedcd0 RK |
996 | continue; |
997 | ||
c09e6498 RS |
998 | if (j == -4) /* `memory', don't cache memory across asm */ |
999 | { | |
bffc6177 | 1000 | XVECEXP (body, 0, i++) |
38a448ca | 1001 | = gen_rtx_CLOBBER (VOIDmode, |
c5c76735 JL |
1002 | gen_rtx_MEM |
1003 | (BLKmode, | |
1004 | gen_rtx_SCRATCH (VOIDmode))); | |
c09e6498 RS |
1005 | continue; |
1006 | } | |
1007 | ||
956d6950 | 1008 | /* Ignore unknown register, error already signaled. */ |
cc1f5387 | 1009 | continue; |
28d81abb RK |
1010 | } |
1011 | ||
1012 | /* Use QImode since that's guaranteed to clobber just one reg. */ | |
acb5d088 HPN |
1013 | clobbered_reg = gen_rtx_REG (QImode, j); |
1014 | ||
1015 | /* Do sanity check for overlap between clobbers and respectively | |
1016 | input and outputs that hasn't been handled. Such overlap | |
1017 | should have been detected and reported above. */ | |
1018 | if (!clobber_conflict_found) | |
1019 | { | |
1020 | int opno; | |
1021 | ||
1022 | /* We test the old body (obody) contents to avoid tripping | |
1023 | over the under-construction body. */ | |
1024 | for (opno = 0; opno < noutputs; opno++) | |
1025 | if (reg_overlap_mentioned_p (clobbered_reg, output_rtx[opno])) | |
1026 | internal_error ("asm clobber conflict with output operand"); | |
1027 | ||
1028 | for (opno = 0; opno < ninputs - ninout; opno++) | |
1029 | if (reg_overlap_mentioned_p (clobbered_reg, | |
1030 | ASM_OPERANDS_INPUT (obody, opno))) | |
1031 | internal_error ("asm clobber conflict with input operand"); | |
1032 | } | |
1033 | ||
b4ccaa16 | 1034 | XVECEXP (body, 0, i++) |
acb5d088 | 1035 | = gen_rtx_CLOBBER (VOIDmode, clobbered_reg); |
28d81abb RK |
1036 | } |
1037 | ||
4977bab6 | 1038 | emit_insn (body); |
28d81abb RK |
1039 | } |
1040 | ||
947255ed RH |
1041 | /* For any outputs that needed reloading into registers, spill them |
1042 | back to where they belong. */ | |
1043 | for (i = 0; i < noutputs; ++i) | |
1044 | if (real_output_rtx[i]) | |
1045 | emit_move_insn (real_output_rtx[i], output_rtx[i]); | |
1046 | ||
28d81abb RK |
1047 | free_temp_slots (); |
1048 | } | |
84b72302 | 1049 | |
6de9cd9a DN |
1050 | void |
1051 | expand_asm_expr (tree exp) | |
1052 | { | |
1053 | int noutputs, i; | |
1054 | tree outputs, tail; | |
1055 | tree *o; | |
1056 | ||
1057 | if (ASM_INPUT_P (exp)) | |
1058 | { | |
1059 | expand_asm (ASM_STRING (exp), ASM_VOLATILE_P (exp)); | |
1060 | return; | |
1061 | } | |
1062 | ||
1063 | outputs = ASM_OUTPUTS (exp); | |
1064 | noutputs = list_length (outputs); | |
1065 | /* o[I] is the place that output number I should be written. */ | |
1066 | o = (tree *) alloca (noutputs * sizeof (tree)); | |
1067 | ||
1068 | /* Record the contents of OUTPUTS before it is modified. */ | |
1069 | for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) | |
1070 | o[i] = TREE_VALUE (tail); | |
1071 | ||
1072 | /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of | |
1073 | OUTPUTS some trees for where the values were actually stored. */ | |
1074 | expand_asm_operands (ASM_STRING (exp), outputs, ASM_INPUTS (exp), | |
1075 | ASM_CLOBBERS (exp), ASM_VOLATILE_P (exp), | |
1076 | input_location); | |
1077 | ||
1078 | /* Copy all the intermediate outputs into the specified outputs. */ | |
1079 | for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) | |
1080 | { | |
1081 | if (o[i] != TREE_VALUE (tail)) | |
1082 | { | |
e836a5a2 | 1083 | expand_assignment (o[i], TREE_VALUE (tail)); |
6de9cd9a DN |
1084 | free_temp_slots (); |
1085 | ||
1086 | /* Restore the original value so that it's correct the next | |
1087 | time we expand this function. */ | |
1088 | TREE_VALUE (tail) = o[i]; | |
1089 | } | |
1090 | } | |
6de9cd9a DN |
1091 | } |
1092 | ||
84b72302 RH |
1093 | /* A subroutine of expand_asm_operands. Check that all operands have |
1094 | the same number of alternatives. Return true if so. */ | |
1095 | ||
1096 | static bool | |
46c5ad27 | 1097 | check_operand_nalternatives (tree outputs, tree inputs) |
84b72302 RH |
1098 | { |
1099 | if (outputs || inputs) | |
1100 | { | |
1101 | tree tmp = TREE_PURPOSE (outputs ? outputs : inputs); | |
1102 | int nalternatives | |
1103 | = n_occurrences (',', TREE_STRING_POINTER (TREE_VALUE (tmp))); | |
1104 | tree next = inputs; | |
1105 | ||
1106 | if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES) | |
1107 | { | |
971801ff | 1108 | error ("too many alternatives in %<asm%>"); |
84b72302 RH |
1109 | return false; |
1110 | } | |
1111 | ||
1112 | tmp = outputs; | |
1113 | while (tmp) | |
1114 | { | |
1115 | const char *constraint | |
1116 | = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tmp))); | |
1117 | ||
1118 | if (n_occurrences (',', constraint) != nalternatives) | |
1119 | { | |
971801ff JM |
1120 | error ("operand constraints for %<asm%> differ " |
1121 | "in number of alternatives"); | |
84b72302 RH |
1122 | return false; |
1123 | } | |
1124 | ||
1125 | if (TREE_CHAIN (tmp)) | |
1126 | tmp = TREE_CHAIN (tmp); | |
1127 | else | |
1128 | tmp = next, next = 0; | |
1129 | } | |
1130 | } | |
1131 | ||
1132 | return true; | |
1133 | } | |
1134 | ||
1135 | /* A subroutine of expand_asm_operands. Check that all operand names | |
1136 | are unique. Return true if so. We rely on the fact that these names | |
1137 | are identifiers, and so have been canonicalized by get_identifier, | |
1138 | so all we need are pointer comparisons. */ | |
1139 | ||
1140 | static bool | |
46c5ad27 | 1141 | check_unique_operand_names (tree outputs, tree inputs) |
84b72302 RH |
1142 | { |
1143 | tree i, j; | |
1144 | ||
1145 | for (i = outputs; i ; i = TREE_CHAIN (i)) | |
1146 | { | |
1147 | tree i_name = TREE_PURPOSE (TREE_PURPOSE (i)); | |
1148 | if (! i_name) | |
1149 | continue; | |
1150 | ||
1151 | for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j)) | |
fc552851 | 1152 | if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j)))) |
84b72302 RH |
1153 | goto failure; |
1154 | } | |
1155 | ||
1156 | for (i = inputs; i ; i = TREE_CHAIN (i)) | |
1157 | { | |
1158 | tree i_name = TREE_PURPOSE (TREE_PURPOSE (i)); | |
1159 | if (! i_name) | |
1160 | continue; | |
1161 | ||
1162 | for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j)) | |
fc552851 | 1163 | if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j)))) |
84b72302 RH |
1164 | goto failure; |
1165 | for (j = outputs; j ; j = TREE_CHAIN (j)) | |
fc552851 | 1166 | if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j)))) |
84b72302 RH |
1167 | goto failure; |
1168 | } | |
1169 | ||
1170 | return true; | |
1171 | ||
1172 | failure: | |
971801ff | 1173 | error ("duplicate asm operand name %qs", |
fc552851 | 1174 | TREE_STRING_POINTER (TREE_PURPOSE (TREE_PURPOSE (i)))); |
84b72302 RH |
1175 | return false; |
1176 | } | |
1177 | ||
1178 | /* A subroutine of expand_asm_operands. Resolve the names of the operands | |
1179 | in *POUTPUTS and *PINPUTS to numbers, and replace the name expansions in | |
1180 | STRING and in the constraints to those numbers. */ | |
1181 | ||
7dc8b126 JM |
1182 | tree |
1183 | resolve_asm_operand_names (tree string, tree outputs, tree inputs) | |
84b72302 | 1184 | { |
7dc8b126 | 1185 | char *buffer; |
84b72302 | 1186 | char *p; |
40209195 | 1187 | const char *c; |
84b72302 RH |
1188 | tree t; |
1189 | ||
1456deaf JM |
1190 | check_unique_operand_names (outputs, inputs); |
1191 | ||
7dc8b126 JM |
1192 | /* Substitute [<name>] in input constraint strings. There should be no |
1193 | named operands in output constraints. */ | |
1194 | for (t = inputs; t ; t = TREE_CHAIN (t)) | |
1195 | { | |
40209195 | 1196 | c = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t))); |
7dc8b126 JM |
1197 | if (strchr (c, '[') != NULL) |
1198 | { | |
1199 | p = buffer = xstrdup (c); | |
1200 | while ((p = strchr (p, '[')) != NULL) | |
1201 | p = resolve_operand_name_1 (p, outputs, inputs); | |
1202 | TREE_VALUE (TREE_PURPOSE (t)) | |
1203 | = build_string (strlen (buffer), buffer); | |
1204 | free (buffer); | |
1205 | } | |
1206 | } | |
1207 | ||
40209195 JM |
1208 | /* Now check for any needed substitutions in the template. */ |
1209 | c = TREE_STRING_POINTER (string); | |
1210 | while ((c = strchr (c, '%')) != NULL) | |
84b72302 | 1211 | { |
40209195 JM |
1212 | if (c[1] == '[') |
1213 | break; | |
1214 | else if (ISALPHA (c[1]) && c[2] == '[') | |
1215 | break; | |
7abcb63a RH |
1216 | else |
1217 | { | |
40209195 | 1218 | c += 1; |
7abcb63a RH |
1219 | continue; |
1220 | } | |
84b72302 RH |
1221 | } |
1222 | ||
40209195 JM |
1223 | if (c) |
1224 | { | |
1225 | /* OK, we need to make a copy so we can perform the substitutions. | |
1226 | Assume that we will not need extra space--we get to remove '[' | |
1227 | and ']', which means we cannot have a problem until we have more | |
1228 | than 999 operands. */ | |
1229 | buffer = xstrdup (TREE_STRING_POINTER (string)); | |
1230 | p = buffer + (c - TREE_STRING_POINTER (string)); | |
caf93cb0 | 1231 | |
40209195 JM |
1232 | while ((p = strchr (p, '%')) != NULL) |
1233 | { | |
1234 | if (p[1] == '[') | |
1235 | p += 1; | |
1236 | else if (ISALPHA (p[1]) && p[2] == '[') | |
1237 | p += 2; | |
1238 | else | |
1239 | { | |
1240 | p += 1; | |
1241 | continue; | |
1242 | } | |
1243 | ||
1244 | p = resolve_operand_name_1 (p, outputs, inputs); | |
1245 | } | |
1246 | ||
1247 | string = build_string (strlen (buffer), buffer); | |
1248 | free (buffer); | |
1249 | } | |
84b72302 | 1250 | |
84b72302 RH |
1251 | return string; |
1252 | } | |
1253 | ||
1254 | /* A subroutine of resolve_operand_names. P points to the '[' for a | |
1255 | potential named operand of the form [<name>]. In place, replace | |
786de7eb | 1256 | the name and brackets with a number. Return a pointer to the |
84b72302 RH |
1257 | balance of the string after substitution. */ |
1258 | ||
1259 | static char * | |
46c5ad27 | 1260 | resolve_operand_name_1 (char *p, tree outputs, tree inputs) |
84b72302 RH |
1261 | { |
1262 | char *q; | |
1263 | int op; | |
1264 | tree t; | |
1265 | size_t len; | |
1266 | ||
1267 | /* Collect the operand name. */ | |
1268 | q = strchr (p, ']'); | |
1269 | if (!q) | |
1270 | { | |
1271 | error ("missing close brace for named operand"); | |
1272 | return strchr (p, '\0'); | |
1273 | } | |
1274 | len = q - p - 1; | |
1275 | ||
1276 | /* Resolve the name to a number. */ | |
1277 | for (op = 0, t = outputs; t ; t = TREE_CHAIN (t), op++) | |
1278 | { | |
fc552851 RS |
1279 | tree name = TREE_PURPOSE (TREE_PURPOSE (t)); |
1280 | if (name) | |
edd1967d | 1281 | { |
fc552851 | 1282 | const char *c = TREE_STRING_POINTER (name); |
edd1967d RH |
1283 | if (strncmp (c, p + 1, len) == 0 && c[len] == '\0') |
1284 | goto found; | |
1285 | } | |
84b72302 RH |
1286 | } |
1287 | for (t = inputs; t ; t = TREE_CHAIN (t), op++) | |
1288 | { | |
fc552851 RS |
1289 | tree name = TREE_PURPOSE (TREE_PURPOSE (t)); |
1290 | if (name) | |
edd1967d | 1291 | { |
fc552851 | 1292 | const char *c = TREE_STRING_POINTER (name); |
edd1967d RH |
1293 | if (strncmp (c, p + 1, len) == 0 && c[len] == '\0') |
1294 | goto found; | |
1295 | } | |
84b72302 RH |
1296 | } |
1297 | ||
1298 | *q = '\0'; | |
971801ff | 1299 | error ("undefined named operand %qs", p + 1); |
84b72302 RH |
1300 | op = 0; |
1301 | found: | |
1302 | ||
1303 | /* Replace the name with the number. Unfortunately, not all libraries | |
1304 | get the return value of sprintf correct, so search for the end of the | |
1305 | generated string by hand. */ | |
1306 | sprintf (p, "%d", op); | |
1307 | p = strchr (p, '\0'); | |
1308 | ||
1309 | /* Verify the no extra buffer space assumption. */ | |
41374e13 | 1310 | gcc_assert (p <= q); |
84b72302 RH |
1311 | |
1312 | /* Shift the rest of the buffer down to fill the gap. */ | |
1313 | memmove (p, q + 1, strlen (q + 1) + 1); | |
1314 | ||
1315 | return p; | |
1316 | } | |
28d81abb | 1317 | \f |
4dfa0342 | 1318 | /* Generate RTL to evaluate the expression EXP. */ |
28d81abb RK |
1319 | |
1320 | void | |
46c5ad27 | 1321 | expand_expr_stmt (tree exp) |
1574ef13 AO |
1322 | { |
1323 | rtx value; | |
1324 | tree type; | |
b6ec8c5f | 1325 | |
4dfa0342 | 1326 | value = expand_expr (exp, const0_rtx, VOIDmode, 0); |
1574ef13 | 1327 | type = TREE_TYPE (exp); |
28d81abb RK |
1328 | |
1329 | /* If all we do is reference a volatile value in memory, | |
1330 | copy it to a register to be sure it is actually touched. */ | |
3c0cb5de | 1331 | if (value && MEM_P (value) && TREE_THIS_VOLATILE (exp)) |
28d81abb | 1332 | { |
1574ef13 | 1333 | if (TYPE_MODE (type) == VOIDmode) |
6a5bbbe6 | 1334 | ; |
1574ef13 AO |
1335 | else if (TYPE_MODE (type) != BLKmode) |
1336 | value = copy_to_reg (value); | |
28d81abb | 1337 | else |
ddbe9812 RS |
1338 | { |
1339 | rtx lab = gen_label_rtx (); | |
4381f7c2 | 1340 | |
ddbe9812 | 1341 | /* Compare the value with itself to reference it. */ |
1574ef13 AO |
1342 | emit_cmp_and_jump_insns (value, value, EQ, |
1343 | expand_expr (TYPE_SIZE (type), | |
c5d5d461 | 1344 | NULL_RTX, VOIDmode, 0), |
d43e0b7d | 1345 | BLKmode, 0, lab); |
ddbe9812 RS |
1346 | emit_label (lab); |
1347 | } | |
28d81abb RK |
1348 | } |
1349 | ||
4dfa0342 | 1350 | /* Free any temporaries used to evaluate this expression. */ |
28d81abb | 1351 | free_temp_slots (); |
28d81abb RK |
1352 | } |
1353 | ||
1354 | /* Warn if EXP contains any computations whose results are not used. | |
caf93cb0 | 1355 | Return 1 if a warning is printed; 0 otherwise. LOCUS is the |
b9861bff | 1356 | (potential) location of the expression. */ |
28d81abb | 1357 | |
150a992a | 1358 | int |
b9861bff | 1359 | warn_if_unused_value (tree exp, location_t locus) |
28d81abb | 1360 | { |
b9861bff | 1361 | restart: |
28d81abb RK |
1362 | if (TREE_USED (exp)) |
1363 | return 0; | |
1364 | ||
9790cefd RH |
1365 | /* Don't warn about void constructs. This includes casting to void, |
1366 | void function calls, and statement expressions with a final cast | |
1367 | to void. */ | |
1368 | if (VOID_TYPE_P (TREE_TYPE (exp))) | |
1369 | return 0; | |
1370 | ||
607bdeaa PB |
1371 | if (EXPR_HAS_LOCATION (exp)) |
1372 | locus = EXPR_LOCATION (exp); | |
b9861bff | 1373 | |
28d81abb RK |
1374 | switch (TREE_CODE (exp)) |
1375 | { | |
1376 | case PREINCREMENT_EXPR: | |
1377 | case POSTINCREMENT_EXPR: | |
1378 | case PREDECREMENT_EXPR: | |
1379 | case POSTDECREMENT_EXPR: | |
1380 | case MODIFY_EXPR: | |
1381 | case INIT_EXPR: | |
1382 | case TARGET_EXPR: | |
1383 | case CALL_EXPR: | |
81797aba | 1384 | case TRY_CATCH_EXPR: |
28d81abb RK |
1385 | case WITH_CLEANUP_EXPR: |
1386 | case EXIT_EXPR: | |
28d81abb RK |
1387 | return 0; |
1388 | ||
1389 | case BIND_EXPR: | |
1390 | /* For a binding, warn if no side effect within it. */ | |
b9861bff RH |
1391 | exp = BIND_EXPR_BODY (exp); |
1392 | goto restart; | |
28d81abb | 1393 | |
de73f171 | 1394 | case SAVE_EXPR: |
b9861bff RH |
1395 | exp = TREE_OPERAND (exp, 0); |
1396 | goto restart; | |
de73f171 | 1397 | |
28d81abb RK |
1398 | case TRUTH_ORIF_EXPR: |
1399 | case TRUTH_ANDIF_EXPR: | |
1400 | /* In && or ||, warn if 2nd operand has no side effect. */ | |
b9861bff RH |
1401 | exp = TREE_OPERAND (exp, 1); |
1402 | goto restart; | |
28d81abb RK |
1403 | |
1404 | case COMPOUND_EXPR: | |
6de9cd9a | 1405 | if (TREE_NO_WARNING (exp)) |
a646a211 | 1406 | return 0; |
b9861bff | 1407 | if (warn_if_unused_value (TREE_OPERAND (exp, 0), locus)) |
28d81abb | 1408 | return 1; |
4d23e509 RS |
1409 | /* Let people do `(foo (), 0)' without a warning. */ |
1410 | if (TREE_CONSTANT (TREE_OPERAND (exp, 1))) | |
1411 | return 0; | |
b9861bff RH |
1412 | exp = TREE_OPERAND (exp, 1); |
1413 | goto restart; | |
28d81abb RK |
1414 | |
1415 | case NOP_EXPR: | |
1416 | case CONVERT_EXPR: | |
b4ac57ab | 1417 | case NON_LVALUE_EXPR: |
28d81abb | 1418 | /* Don't warn about conversions not explicit in the user's program. */ |
6de9cd9a | 1419 | if (TREE_NO_WARNING (exp)) |
28d81abb RK |
1420 | return 0; |
1421 | /* Assignment to a cast usually results in a cast of a modify. | |
55cd1c09 JW |
1422 | Don't complain about that. There can be an arbitrary number of |
1423 | casts before the modify, so we must loop until we find the first | |
1424 | non-cast expression and then test to see if that is a modify. */ | |
1425 | { | |
1426 | tree tem = TREE_OPERAND (exp, 0); | |
1427 | ||
1428 | while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR) | |
1429 | tem = TREE_OPERAND (tem, 0); | |
1430 | ||
de73f171 RK |
1431 | if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR |
1432 | || TREE_CODE (tem) == CALL_EXPR) | |
55cd1c09 JW |
1433 | return 0; |
1434 | } | |
7133e992 | 1435 | goto maybe_warn; |
28d81abb | 1436 | |
d1e1adfb JM |
1437 | case INDIRECT_REF: |
1438 | /* Don't warn about automatic dereferencing of references, since | |
1439 | the user cannot control it. */ | |
1440 | if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE) | |
b9861bff RH |
1441 | { |
1442 | exp = TREE_OPERAND (exp, 0); | |
1443 | goto restart; | |
1444 | } | |
4381f7c2 KH |
1445 | /* Fall through. */ |
1446 | ||
28d81abb | 1447 | default: |
ddbe9812 | 1448 | /* Referencing a volatile value is a side effect, so don't warn. */ |
6615c446 | 1449 | if ((DECL_P (exp) || REFERENCE_CLASS_P (exp)) |
ddbe9812 RS |
1450 | && TREE_THIS_VOLATILE (exp)) |
1451 | return 0; | |
8d5e6e25 RK |
1452 | |
1453 | /* If this is an expression which has no operands, there is no value | |
1454 | to be unused. There are no such language-independent codes, | |
1455 | but front ends may define such. */ | |
6615c446 | 1456 | if (EXPRESSION_CLASS_P (exp) && TREE_CODE_LENGTH (TREE_CODE (exp)) == 0) |
8d5e6e25 RK |
1457 | return 0; |
1458 | ||
7133e992 JJ |
1459 | maybe_warn: |
1460 | /* If this is an expression with side effects, don't warn. */ | |
1461 | if (TREE_SIDE_EFFECTS (exp)) | |
1462 | return 0; | |
1463 | ||
b9861bff | 1464 | warning ("%Hvalue computed is not used", &locus); |
28d81abb RK |
1465 | return 1; |
1466 | } | |
1467 | } | |
28d81abb | 1468 | |
28d81abb RK |
1469 | \f |
1470 | /* Generate RTL to return from the current function, with no value. | |
1471 | (That is, we do not do anything about returning any value.) */ | |
1472 | ||
1473 | void | |
46c5ad27 | 1474 | expand_null_return (void) |
28d81abb | 1475 | { |
4381f7c2 | 1476 | /* If this function was declared to return a value, but we |
bd695e1e | 1477 | didn't, clobber the return registers so that they are not |
a1f300c0 | 1478 | propagated live to the rest of the function. */ |
c13fde05 | 1479 | clobber_return_register (); |
28d81abb | 1480 | |
ac45df5d | 1481 | expand_null_return_1 (); |
28d81abb RK |
1482 | } |
1483 | ||
6e3077c6 EB |
1484 | /* Generate RTL to return directly from the current function. |
1485 | (That is, we bypass any return value.) */ | |
1486 | ||
1487 | void | |
1488 | expand_naked_return (void) | |
1489 | { | |
ac45df5d | 1490 | rtx end_label; |
6e3077c6 EB |
1491 | |
1492 | clear_pending_stack_adjust (); | |
1493 | do_pending_stack_adjust (); | |
6e3077c6 | 1494 | |
ac45df5d | 1495 | end_label = naked_return_label; |
6e3077c6 EB |
1496 | if (end_label == 0) |
1497 | end_label = naked_return_label = gen_label_rtx (); | |
ac45df5d RH |
1498 | |
1499 | emit_jump (end_label); | |
6e3077c6 EB |
1500 | } |
1501 | ||
28d81abb RK |
1502 | /* Generate RTL to return from the current function, with value VAL. */ |
1503 | ||
8d800403 | 1504 | static void |
46c5ad27 | 1505 | expand_value_return (rtx val) |
28d81abb | 1506 | { |
28d81abb RK |
1507 | /* Copy the value to the return location |
1508 | unless it's already there. */ | |
1509 | ||
07a236b6 | 1510 | rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl)); |
28d81abb | 1511 | if (return_reg != val) |
77636079 | 1512 | { |
77636079 | 1513 | tree type = TREE_TYPE (DECL_RESULT (current_function_decl)); |
61f71b34 DD |
1514 | if (targetm.calls.promote_function_return (TREE_TYPE (current_function_decl))) |
1515 | { | |
8df83eae | 1516 | int unsignedp = TYPE_UNSIGNED (type); |
61f71b34 DD |
1517 | enum machine_mode old_mode |
1518 | = DECL_MODE (DECL_RESULT (current_function_decl)); | |
1519 | enum machine_mode mode | |
1520 | = promote_mode (type, old_mode, &unsignedp, 1); | |
1521 | ||
1522 | if (mode != old_mode) | |
1523 | val = convert_modes (mode, old_mode, val, unsignedp); | |
1524 | } | |
14a774a9 | 1525 | if (GET_CODE (return_reg) == PARALLEL) |
6e985040 | 1526 | emit_group_load (return_reg, val, type, int_size_in_bytes (type)); |
14a774a9 | 1527 | else |
77636079 RS |
1528 | emit_move_insn (return_reg, val); |
1529 | } | |
14a774a9 | 1530 | |
ac45df5d | 1531 | expand_null_return_1 (); |
28d81abb RK |
1532 | } |
1533 | ||
ac45df5d | 1534 | /* Output a return with no value. */ |
28d81abb RK |
1535 | |
1536 | static void | |
ac45df5d | 1537 | expand_null_return_1 (void) |
28d81abb | 1538 | { |
28d81abb RK |
1539 | clear_pending_stack_adjust (); |
1540 | do_pending_stack_adjust (); | |
526c334b | 1541 | emit_jump (return_label); |
28d81abb RK |
1542 | } |
1543 | \f | |
1544 | /* Generate RTL to evaluate the expression RETVAL and return it | |
1545 | from the current function. */ | |
1546 | ||
1547 | void | |
46c5ad27 | 1548 | expand_return (tree retval) |
28d81abb | 1549 | { |
19e7881c | 1550 | rtx result_rtl; |
b3694847 | 1551 | rtx val = 0; |
28d81abb | 1552 | tree retval_rhs; |
28d81abb RK |
1553 | |
1554 | /* If function wants no value, give it none. */ | |
1555 | if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE) | |
1556 | { | |
37366632 | 1557 | expand_expr (retval, NULL_RTX, VOIDmode, 0); |
28d81abb RK |
1558 | expand_null_return (); |
1559 | return; | |
1560 | } | |
1561 | ||
ea11ca7e | 1562 | if (retval == error_mark_node) |
c9407e4c MM |
1563 | { |
1564 | /* Treat this like a return of no value from a function that | |
1565 | returns a value. */ | |
1566 | expand_null_return (); | |
786de7eb | 1567 | return; |
c9407e4c | 1568 | } |
ac45df5d RH |
1569 | else if ((TREE_CODE (retval) == MODIFY_EXPR |
1570 | || TREE_CODE (retval) == INIT_EXPR) | |
28d81abb RK |
1571 | && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL) |
1572 | retval_rhs = TREE_OPERAND (retval, 1); | |
28d81abb | 1573 | else |
6de9cd9a | 1574 | retval_rhs = retval; |
28d81abb | 1575 | |
19e7881c MM |
1576 | result_rtl = DECL_RTL (DECL_RESULT (current_function_decl)); |
1577 | ||
6f4a43e0 ZW |
1578 | /* If we are returning the RESULT_DECL, then the value has already |
1579 | been stored into it, so we don't have to do anything special. */ | |
1580 | if (TREE_CODE (retval_rhs) == RESULT_DECL) | |
1581 | expand_value_return (result_rtl); | |
1582 | ||
4c485b63 JL |
1583 | /* If the result is an aggregate that is being returned in one (or more) |
1584 | registers, load the registers here. The compiler currently can't handle | |
1585 | copying a BLKmode value into registers. We could put this code in a | |
1586 | more general area (for use by everyone instead of just function | |
1587 | call/return), but until this feature is generally usable it is kept here | |
ac45df5d | 1588 | (and in expand_call). */ |
4c485b63 | 1589 | |
6f4a43e0 ZW |
1590 | else if (retval_rhs != 0 |
1591 | && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode | |
1592 | && REG_P (result_rtl)) | |
4c485b63 | 1593 | { |
770ae6cc RK |
1594 | int i; |
1595 | unsigned HOST_WIDE_INT bitpos, xbitpos; | |
c988af2b | 1596 | unsigned HOST_WIDE_INT padding_correction = 0; |
770ae6cc RK |
1597 | unsigned HOST_WIDE_INT bytes |
1598 | = int_size_in_bytes (TREE_TYPE (retval_rhs)); | |
4c485b63 | 1599 | int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD; |
770ae6cc RK |
1600 | unsigned int bitsize |
1601 | = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), BITS_PER_WORD); | |
703ad42b | 1602 | rtx *result_pseudos = alloca (sizeof (rtx) * n_regs); |
c16ddde3 | 1603 | rtx result_reg, src = NULL_RTX, dst = NULL_RTX; |
4c485b63 | 1604 | rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0); |
af55da56 | 1605 | enum machine_mode tmpmode, result_reg_mode; |
4c485b63 | 1606 | |
2954d7db RK |
1607 | if (bytes == 0) |
1608 | { | |
1609 | expand_null_return (); | |
1610 | return; | |
1611 | } | |
1612 | ||
c988af2b RS |
1613 | /* If the structure doesn't take up a whole number of words, see |
1614 | whether the register value should be padded on the left or on | |
1615 | the right. Set PADDING_CORRECTION to the number of padding | |
1616 | bits needed on the left side. | |
1617 | ||
1618 | In most ABIs, the structure will be returned at the least end of | |
1619 | the register, which translates to right padding on little-endian | |
1620 | targets and left padding on big-endian targets. The opposite | |
1621 | holds if the structure is returned at the most significant | |
1622 | end of the register. */ | |
1623 | if (bytes % UNITS_PER_WORD != 0 | |
1624 | && (targetm.calls.return_in_msb (TREE_TYPE (retval_rhs)) | |
1625 | ? !BYTES_BIG_ENDIAN | |
1626 | : BYTES_BIG_ENDIAN)) | |
1627 | padding_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD) | |
1628 | * BITS_PER_UNIT)); | |
a7f875d7 | 1629 | |
4381f7c2 | 1630 | /* Copy the structure BITSIZE bits at a time. */ |
c988af2b | 1631 | for (bitpos = 0, xbitpos = padding_correction; |
a7f875d7 RK |
1632 | bitpos < bytes * BITS_PER_UNIT; |
1633 | bitpos += bitsize, xbitpos += bitsize) | |
4c485b63 | 1634 | { |
a7f875d7 | 1635 | /* We need a new destination pseudo each time xbitpos is |
c988af2b | 1636 | on a word boundary and when xbitpos == padding_correction |
a7f875d7 RK |
1637 | (the first time through). */ |
1638 | if (xbitpos % BITS_PER_WORD == 0 | |
c988af2b | 1639 | || xbitpos == padding_correction) |
4c485b63 | 1640 | { |
a7f875d7 RK |
1641 | /* Generate an appropriate register. */ |
1642 | dst = gen_reg_rtx (word_mode); | |
1643 | result_pseudos[xbitpos / BITS_PER_WORD] = dst; | |
1644 | ||
8a38ed86 AM |
1645 | /* Clear the destination before we move anything into it. */ |
1646 | emit_move_insn (dst, CONST0_RTX (GET_MODE (dst))); | |
4c485b63 | 1647 | } |
a7f875d7 RK |
1648 | |
1649 | /* We need a new source operand each time bitpos is on a word | |
1650 | boundary. */ | |
1651 | if (bitpos % BITS_PER_WORD == 0) | |
1652 | src = operand_subword_force (result_val, | |
1653 | bitpos / BITS_PER_WORD, | |
1654 | BLKmode); | |
1655 | ||
1656 | /* Use bitpos for the source extraction (left justified) and | |
1657 | xbitpos for the destination store (right justified). */ | |
1658 | store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode, | |
1659 | extract_bit_field (src, bitsize, | |
1660 | bitpos % BITS_PER_WORD, 1, | |
b3520980 | 1661 | NULL_RTX, word_mode, word_mode)); |
4c485b63 JL |
1662 | } |
1663 | ||
c988af2b RS |
1664 | tmpmode = GET_MODE (result_rtl); |
1665 | if (tmpmode == BLKmode) | |
1666 | { | |
1667 | /* Find the smallest integer mode large enough to hold the | |
1668 | entire structure and use that mode instead of BLKmode | |
1669 | on the USE insn for the return register. */ | |
1670 | for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT); | |
1671 | tmpmode != VOIDmode; | |
1672 | tmpmode = GET_MODE_WIDER_MODE (tmpmode)) | |
1673 | /* Have we found a large enough mode? */ | |
1674 | if (GET_MODE_SIZE (tmpmode) >= bytes) | |
1675 | break; | |
4c485b63 | 1676 | |
41374e13 NS |
1677 | /* A suitable mode should have been found. */ |
1678 | gcc_assert (tmpmode != VOIDmode); | |
4c485b63 | 1679 | |
c988af2b RS |
1680 | PUT_MODE (result_rtl, tmpmode); |
1681 | } | |
3ffeb8f1 | 1682 | |
af55da56 JW |
1683 | if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode)) |
1684 | result_reg_mode = word_mode; | |
1685 | else | |
1686 | result_reg_mode = tmpmode; | |
1687 | result_reg = gen_reg_rtx (result_reg_mode); | |
1688 | ||
3ffeb8f1 | 1689 | for (i = 0; i < n_regs; i++) |
af55da56 | 1690 | emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode), |
3ffeb8f1 | 1691 | result_pseudos[i]); |
4c485b63 | 1692 | |
af55da56 JW |
1693 | if (tmpmode != result_reg_mode) |
1694 | result_reg = gen_lowpart (tmpmode, result_reg); | |
1695 | ||
4c485b63 JL |
1696 | expand_value_return (result_reg); |
1697 | } | |
7cc8342c RH |
1698 | else if (retval_rhs != 0 |
1699 | && !VOID_TYPE_P (TREE_TYPE (retval_rhs)) | |
f8cfc6aa | 1700 | && (REG_P (result_rtl) |
7cc8342c | 1701 | || (GET_CODE (result_rtl) == PARALLEL))) |
28d81abb | 1702 | { |
14a774a9 RK |
1703 | /* Calculate the return value into a temporary (usually a pseudo |
1704 | reg). */ | |
1da68f56 RK |
1705 | tree ot = TREE_TYPE (DECL_RESULT (current_function_decl)); |
1706 | tree nt = build_qualified_type (ot, TYPE_QUALS (ot) | TYPE_QUAL_CONST); | |
1707 | ||
1708 | val = assign_temp (nt, 0, 0, 1); | |
dd98f85c JM |
1709 | val = expand_expr (retval_rhs, val, GET_MODE (val), 0); |
1710 | val = force_not_mem (val); | |
ac45df5d | 1711 | /* Return the calculated value. */ |
bef5d8b6 | 1712 | expand_value_return (val); |
28d81abb RK |
1713 | } |
1714 | else | |
1715 | { | |
ac45df5d | 1716 | /* No hard reg used; calculate value into hard return reg. */ |
cba389cd | 1717 | expand_expr (retval, const0_rtx, VOIDmode, 0); |
14a774a9 | 1718 | expand_value_return (result_rtl); |
28d81abb RK |
1719 | } |
1720 | } | |
28d81abb | 1721 | \f |
0e9e1e0a | 1722 | /* Given a pointer to a BLOCK node return nonzero if (and only if) the node |
deb5e280 JM |
1723 | in question represents the outermost pair of curly braces (i.e. the "body |
1724 | block") of a function or method. | |
1725 | ||
1726 | For any BLOCK node representing a "body block" of a function or method, the | |
1727 | BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which | |
1728 | represents the outermost (function) scope for the function or method (i.e. | |
1729 | the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of | |
4381f7c2 | 1730 | *that* node in turn will point to the relevant FUNCTION_DECL node. */ |
deb5e280 JM |
1731 | |
1732 | int | |
46c5ad27 | 1733 | is_body_block (tree stmt) |
deb5e280 | 1734 | { |
2896d056 ZW |
1735 | if (lang_hooks.no_body_blocks) |
1736 | return 0; | |
1737 | ||
deb5e280 JM |
1738 | if (TREE_CODE (stmt) == BLOCK) |
1739 | { | |
1740 | tree parent = BLOCK_SUPERCONTEXT (stmt); | |
1741 | ||
1742 | if (parent && TREE_CODE (parent) == BLOCK) | |
1743 | { | |
1744 | tree grandparent = BLOCK_SUPERCONTEXT (parent); | |
1745 | ||
1746 | if (grandparent && TREE_CODE (grandparent) == FUNCTION_DECL) | |
1747 | return 1; | |
1748 | } | |
1749 | } | |
1750 | ||
1751 | return 0; | |
1752 | } | |
1753 | ||
ba716ac9 BS |
1754 | /* Emit code to restore vital registers at the beginning of a nonlocal goto |
1755 | handler. */ | |
1756 | static void | |
46c5ad27 | 1757 | expand_nl_goto_receiver (void) |
ba716ac9 | 1758 | { |
6de9cd9a | 1759 | /* Clobber the FP when we get here, so we have to make sure it's |
e292dbb0 WH |
1760 | marked as used by this function. */ |
1761 | emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx)); | |
1762 | ||
1763 | /* Mark the static chain as clobbered here so life information | |
1764 | doesn't get messed up for it. */ | |
1765 | emit_insn (gen_rtx_CLOBBER (VOIDmode, static_chain_rtx)); | |
1766 | ||
ba716ac9 BS |
1767 | #ifdef HAVE_nonlocal_goto |
1768 | if (! HAVE_nonlocal_goto) | |
1769 | #endif | |
1770 | /* First adjust our frame pointer to its actual value. It was | |
1771 | previously set to the start of the virtual area corresponding to | |
1772 | the stacked variables when we branched here and now needs to be | |
1773 | adjusted to the actual hardware fp value. | |
1774 | ||
1775 | Assignments are to virtual registers are converted by | |
1776 | instantiate_virtual_regs into the corresponding assignment | |
1777 | to the underlying register (fp in this case) that makes | |
1778 | the original assignment true. | |
1779 | So the following insn will actually be | |
1780 | decrementing fp by STARTING_FRAME_OFFSET. */ | |
1781 | emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx); | |
1782 | ||
1783 | #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM | |
1784 | if (fixed_regs[ARG_POINTER_REGNUM]) | |
1785 | { | |
1786 | #ifdef ELIMINABLE_REGS | |
1787 | /* If the argument pointer can be eliminated in favor of the | |
1788 | frame pointer, we don't need to restore it. We assume here | |
1789 | that if such an elimination is present, it can always be used. | |
1790 | This is the case on all known machines; if we don't make this | |
1791 | assumption, we do unnecessary saving on many machines. */ | |
8b60264b | 1792 | static const struct elims {const int from, to;} elim_regs[] = ELIMINABLE_REGS; |
ba716ac9 BS |
1793 | size_t i; |
1794 | ||
b6a1cbae | 1795 | for (i = 0; i < ARRAY_SIZE (elim_regs); i++) |
ba716ac9 BS |
1796 | if (elim_regs[i].from == ARG_POINTER_REGNUM |
1797 | && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM) | |
1798 | break; | |
1799 | ||
b6a1cbae | 1800 | if (i == ARRAY_SIZE (elim_regs)) |
ba716ac9 BS |
1801 | #endif |
1802 | { | |
1803 | /* Now restore our arg pointer from the address at which it | |
278ed218 | 1804 | was saved in our stack frame. */ |
ba716ac9 | 1805 | emit_move_insn (virtual_incoming_args_rtx, |
278ed218 | 1806 | copy_to_reg (get_arg_pointer_save_area (cfun))); |
ba716ac9 BS |
1807 | } |
1808 | } | |
1809 | #endif | |
1810 | ||
1811 | #ifdef HAVE_nonlocal_goto_receiver | |
1812 | if (HAVE_nonlocal_goto_receiver) | |
1813 | emit_insn (gen_nonlocal_goto_receiver ()); | |
1814 | #endif | |
e292dbb0 WH |
1815 | |
1816 | /* @@@ This is a kludge. Not all machine descriptions define a blockage | |
1817 | insn, but we must not allow the code we just generated to be reordered | |
1818 | by scheduling. Specifically, the update of the frame pointer must | |
1819 | happen immediately, not later. So emit an ASM_INPUT to act as blockage | |
1820 | insn. */ | |
1821 | emit_insn (gen_rtx_ASM_INPUT (VOIDmode, "")); | |
ba716ac9 | 1822 | } |
28d81abb RK |
1823 | \f |
1824 | /* Generate RTL for the automatic variable declaration DECL. | |
ec5cd386 | 1825 | (Other kinds of declarations are simply ignored if seen here.) */ |
28d81abb RK |
1826 | |
1827 | void | |
46c5ad27 | 1828 | expand_decl (tree decl) |
28d81abb | 1829 | { |
ca695ac9 JB |
1830 | tree type; |
1831 | ||
ca695ac9 | 1832 | type = TREE_TYPE (decl); |
28d81abb | 1833 | |
eabb9ed0 RK |
1834 | /* For a CONST_DECL, set mode, alignment, and sizes from those of the |
1835 | type in case this node is used in a reference. */ | |
1836 | if (TREE_CODE (decl) == CONST_DECL) | |
1837 | { | |
1838 | DECL_MODE (decl) = TYPE_MODE (type); | |
1839 | DECL_ALIGN (decl) = TYPE_ALIGN (type); | |
1840 | DECL_SIZE (decl) = TYPE_SIZE (type); | |
1841 | DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (type); | |
1842 | return; | |
1843 | } | |
28d81abb | 1844 | |
eabb9ed0 RK |
1845 | /* Otherwise, only automatic variables need any expansion done. Static and |
1846 | external variables, and external functions, will be handled by | |
1847 | `assemble_variable' (called from finish_decl). TYPE_DECL requires | |
1848 | nothing. PARM_DECLs are handled in `assign_parms'. */ | |
28d81abb RK |
1849 | if (TREE_CODE (decl) != VAR_DECL) |
1850 | return; | |
eabb9ed0 | 1851 | |
44fe2e80 | 1852 | if (TREE_STATIC (decl) || DECL_EXTERNAL (decl)) |
28d81abb RK |
1853 | return; |
1854 | ||
1855 | /* Create the RTL representation for the variable. */ | |
1856 | ||
1857 | if (type == error_mark_node) | |
19e7881c | 1858 | SET_DECL_RTL (decl, gen_rtx_MEM (BLKmode, const0_rtx)); |
1da68f56 | 1859 | |
28d81abb RK |
1860 | else if (DECL_SIZE (decl) == 0) |
1861 | /* Variable with incomplete type. */ | |
1862 | { | |
abde42f7 | 1863 | rtx x; |
28d81abb RK |
1864 | if (DECL_INITIAL (decl) == 0) |
1865 | /* Error message was already done; now avoid a crash. */ | |
abde42f7 | 1866 | x = gen_rtx_MEM (BLKmode, const0_rtx); |
28d81abb RK |
1867 | else |
1868 | /* An initializer is going to decide the size of this array. | |
1869 | Until we know the size, represent its address with a reg. */ | |
abde42f7 | 1870 | x = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode)); |
3bdf5ad1 | 1871 | |
abde42f7 JH |
1872 | set_mem_attributes (x, decl, 1); |
1873 | SET_DECL_RTL (decl, x); | |
28d81abb | 1874 | } |
8fff4fc1 | 1875 | else if (use_register_for_decl (decl)) |
28d81abb RK |
1876 | { |
1877 | /* Automatic variable that can go in a register. */ | |
8df83eae | 1878 | int unsignedp = TYPE_UNSIGNED (type); |
28612f9e RK |
1879 | enum machine_mode reg_mode |
1880 | = promote_mode (type, DECL_MODE (decl), &unsignedp, 0); | |
98f3b471 | 1881 | |
19e7881c | 1882 | SET_DECL_RTL (decl, gen_reg_rtx (reg_mode)); |
0d4903b8 | 1883 | |
0b068ee9 | 1884 | /* Note if the object is a user variable. */ |
7dc8b126 | 1885 | if (!DECL_ARTIFICIAL (decl)) |
0b068ee9 JL |
1886 | { |
1887 | mark_user_reg (DECL_RTL (decl)); | |
1888 | ||
1889 | /* Trust user variables which have a pointer type to really | |
1890 | be pointers. Do not trust compiler generated temporaries | |
1891 | as our type system is totally busted as it relates to | |
1892 | pointer arithmetic which translates into lots of compiler | |
1893 | generated objects with pointer types, but which are not really | |
1894 | pointers. */ | |
1895 | if (POINTER_TYPE_P (type)) | |
1896 | mark_reg_pointer (DECL_RTL (decl), | |
1897 | TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl)))); | |
1898 | } | |
28d81abb | 1899 | } |
0df15c2c | 1900 | |
4559fd9e | 1901 | else if (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST |
5e4ef18a | 1902 | && ! (flag_stack_check && ! STACK_CHECK_BUILTIN |
05bccae2 RK |
1903 | && 0 < compare_tree_int (DECL_SIZE_UNIT (decl), |
1904 | STACK_CHECK_MAX_VAR_SIZE))) | |
28d81abb RK |
1905 | { |
1906 | /* Variable of fixed size that goes on the stack. */ | |
1907 | rtx oldaddr = 0; | |
1908 | rtx addr; | |
0d4903b8 | 1909 | rtx x; |
28d81abb RK |
1910 | |
1911 | /* If we previously made RTL for this decl, it must be an array | |
1912 | whose size was determined by the initializer. | |
1913 | The old address was a register; set that register now | |
1914 | to the proper address. */ | |
19e7881c | 1915 | if (DECL_RTL_SET_P (decl)) |
28d81abb | 1916 | { |
41374e13 NS |
1917 | gcc_assert (MEM_P (DECL_RTL (decl))); |
1918 | gcc_assert (REG_P (XEXP (DECL_RTL (decl), 0))); | |
28d81abb RK |
1919 | oldaddr = XEXP (DECL_RTL (decl), 0); |
1920 | } | |
1921 | ||
28d81abb RK |
1922 | /* Set alignment we actually gave this decl. */ |
1923 | DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT | |
1924 | : GET_MODE_BITSIZE (DECL_MODE (decl))); | |
11cf4d18 | 1925 | DECL_USER_ALIGN (decl) = 0; |
28d81abb | 1926 | |
9432c136 | 1927 | x = assign_temp (decl, 1, 1, 1); |
0d4903b8 RK |
1928 | set_mem_attributes (x, decl, 1); |
1929 | SET_DECL_RTL (decl, x); | |
1930 | ||
28d81abb RK |
1931 | if (oldaddr) |
1932 | { | |
1933 | addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr); | |
1934 | if (addr != oldaddr) | |
1935 | emit_move_insn (oldaddr, addr); | |
1936 | } | |
28d81abb RK |
1937 | } |
1938 | else | |
1939 | /* Dynamic-size object: must push space on the stack. */ | |
1940 | { | |
abde42f7 | 1941 | rtx address, size, x; |
28d81abb RK |
1942 | |
1943 | /* Record the stack pointer on entry to block, if have | |
1944 | not already done so. */ | |
7393c642 | 1945 | do_pending_stack_adjust (); |
28d81abb | 1946 | |
1c9766da RK |
1947 | /* Compute the variable's size, in bytes. This will expand any |
1948 | needed SAVE_EXPRs for the first time. */ | |
4559fd9e | 1949 | size = expand_expr (DECL_SIZE_UNIT (decl), NULL_RTX, VOIDmode, 0); |
28d81abb RK |
1950 | free_temp_slots (); |
1951 | ||
ff91ad08 | 1952 | /* Allocate space on the stack for the variable. Note that |
4381f7c2 | 1953 | DECL_ALIGN says how the variable is to be aligned and we |
ff91ad08 RK |
1954 | cannot use it to conclude anything about the alignment of |
1955 | the size. */ | |
37366632 | 1956 | address = allocate_dynamic_stack_space (size, NULL_RTX, |
ff91ad08 | 1957 | TYPE_ALIGN (TREE_TYPE (decl))); |
28d81abb | 1958 | |
28d81abb | 1959 | /* Reference the variable indirect through that rtx. */ |
abde42f7 JH |
1960 | x = gen_rtx_MEM (DECL_MODE (decl), address); |
1961 | set_mem_attributes (x, decl, 1); | |
1962 | SET_DECL_RTL (decl, x); | |
28d81abb | 1963 | |
2207e295 | 1964 | |
28d81abb RK |
1965 | /* Indicate the alignment we actually gave this variable. */ |
1966 | #ifdef STACK_BOUNDARY | |
1967 | DECL_ALIGN (decl) = STACK_BOUNDARY; | |
1968 | #else | |
1969 | DECL_ALIGN (decl) = BIGGEST_ALIGNMENT; | |
1970 | #endif | |
11cf4d18 | 1971 | DECL_USER_ALIGN (decl) = 0; |
28d81abb | 1972 | } |
28d81abb RK |
1973 | } |
1974 | \f | |
6de9cd9a DN |
1975 | /* Emit code to save the current value of stack. */ |
1976 | rtx | |
1977 | expand_stack_save (void) | |
1978 | { | |
1979 | rtx ret = NULL_RTX; | |
1980 | ||
1981 | do_pending_stack_adjust (); | |
1982 | emit_stack_save (SAVE_BLOCK, &ret, NULL_RTX); | |
1983 | return ret; | |
1984 | } | |
1985 | ||
1986 | /* Emit code to restore the current value of stack. */ | |
1987 | void | |
1988 | expand_stack_restore (tree var) | |
1989 | { | |
1990 | rtx sa = DECL_RTL (var); | |
1991 | ||
1992 | emit_stack_restore (SAVE_BLOCK, sa, NULL_RTX); | |
1993 | } | |
28d81abb RK |
1994 | \f |
1995 | /* DECL is an anonymous union. CLEANUP is a cleanup for DECL. | |
1996 | DECL_ELTS is the list of elements that belong to DECL's type. | |
1997 | In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */ | |
1998 | ||
1999 | void | |
ac45df5d RH |
2000 | expand_anon_union_decl (tree decl, tree cleanup ATTRIBUTE_UNUSED, |
2001 | tree decl_elts) | |
28d81abb | 2002 | { |
28d81abb | 2003 | rtx x; |
8a693bd0 | 2004 | tree t; |
28d81abb | 2005 | |
8a693bd0 MM |
2006 | /* If any of the elements are addressable, so is the entire union. */ |
2007 | for (t = decl_elts; t; t = TREE_CHAIN (t)) | |
2008 | if (TREE_ADDRESSABLE (TREE_VALUE (t))) | |
2009 | { | |
2010 | TREE_ADDRESSABLE (decl) = 1; | |
2011 | break; | |
2012 | } | |
4381f7c2 | 2013 | |
ec5cd386 | 2014 | expand_decl (decl); |
28d81abb RK |
2015 | x = DECL_RTL (decl); |
2016 | ||
8a693bd0 MM |
2017 | /* Go through the elements, assigning RTL to each. */ |
2018 | for (t = decl_elts; t; t = TREE_CHAIN (t)) | |
28d81abb | 2019 | { |
8a693bd0 | 2020 | tree decl_elt = TREE_VALUE (t); |
28d81abb | 2021 | enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt)); |
41374e13 | 2022 | rtx decl_rtl; |
28d81abb | 2023 | |
3256b817 JJ |
2024 | /* If any of the elements are addressable, so is the entire |
2025 | union. */ | |
2026 | if (TREE_USED (decl_elt)) | |
2027 | TREE_USED (decl) = 1; | |
2028 | ||
7b9032dd JM |
2029 | /* Propagate the union's alignment to the elements. */ |
2030 | DECL_ALIGN (decl_elt) = DECL_ALIGN (decl); | |
11cf4d18 | 2031 | DECL_USER_ALIGN (decl_elt) = DECL_USER_ALIGN (decl); |
7b9032dd JM |
2032 | |
2033 | /* If the element has BLKmode and the union doesn't, the union is | |
2034 | aligned such that the element doesn't need to have BLKmode, so | |
2035 | change the element's mode to the appropriate one for its size. */ | |
2036 | if (mode == BLKmode && DECL_MODE (decl) != BLKmode) | |
2037 | DECL_MODE (decl_elt) = mode | |
05bccae2 | 2038 | = mode_for_size_tree (DECL_SIZE (decl_elt), MODE_INT, 1); |
7b9032dd | 2039 | |
41374e13 NS |
2040 | if (mode == GET_MODE (x)) |
2041 | decl_rtl = x; | |
2042 | else if (MEM_P (x)) | |
2043 | /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we | |
2044 | instead create a new MEM rtx with the proper mode. */ | |
2045 | decl_rtl = adjust_address_nv (x, mode, 0); | |
2046 | else | |
28d81abb | 2047 | { |
41374e13 NS |
2048 | gcc_assert (REG_P (x)); |
2049 | decl_rtl = gen_lowpart_SUBREG (mode, x); | |
28d81abb | 2050 | } |
41374e13 | 2051 | SET_DECL_RTL (decl_elt, decl_rtl); |
28d81abb RK |
2052 | } |
2053 | } | |
2054 | \f | |
7efcb746 PB |
2055 | /* Do the insertion of a case label into case_list. The labels are |
2056 | fed to us in descending order from the sorted vector of case labels used | |
a6c0a76c | 2057 | in the tree part of the middle end. So the list we construct is |
eb172681 RS |
2058 | sorted in ascending order. The bounds on the case range, LOW and HIGH, |
2059 | are converted to case's index type TYPE. */ | |
57641239 | 2060 | |
eb172681 RS |
2061 | static struct case_node * |
2062 | add_case_node (struct case_node *head, tree type, tree low, tree high, | |
2063 | tree label) | |
57641239 | 2064 | { |
eb172681 | 2065 | tree min_value, max_value; |
a6c0a76c | 2066 | struct case_node *r; |
57641239 | 2067 | |
eb172681 RS |
2068 | gcc_assert (TREE_CODE (low) == INTEGER_CST); |
2069 | gcc_assert (!high || TREE_CODE (high) == INTEGER_CST); | |
2070 | ||
2071 | min_value = TYPE_MIN_VALUE (type); | |
2072 | max_value = TYPE_MAX_VALUE (type); | |
2073 | ||
56cb9733 MM |
2074 | /* If there's no HIGH value, then this is not a case range; it's |
2075 | just a simple case label. But that's just a degenerate case | |
a6c0a76c SB |
2076 | range. |
2077 | If the bounds are equal, turn this into the one-value case. */ | |
2078 | if (!high || tree_int_cst_equal (low, high)) | |
eb172681 RS |
2079 | { |
2080 | /* If the simple case value is unreachable, ignore it. */ | |
b77aa1f7 AP |
2081 | if ((TREE_CODE (min_value) == INTEGER_CST |
2082 | && tree_int_cst_compare (low, min_value) < 0) | |
2083 | || (TREE_CODE (max_value) == INTEGER_CST | |
2084 | && tree_int_cst_compare (low, max_value) > 0)) | |
eb172681 RS |
2085 | return head; |
2086 | low = fold_convert (type, low); | |
2087 | high = low; | |
2088 | } | |
2089 | else | |
2090 | { | |
2091 | /* If the entire case range is unreachable, ignore it. */ | |
b77aa1f7 AP |
2092 | if ((TREE_CODE (min_value) == INTEGER_CST |
2093 | && tree_int_cst_compare (high, min_value) < 0) | |
2094 | || (TREE_CODE (max_value) == INTEGER_CST | |
2095 | && tree_int_cst_compare (low, max_value) > 0)) | |
eb172681 RS |
2096 | return head; |
2097 | ||
2098 | /* If the lower bound is less than the index type's minimum | |
2099 | value, truncate the range bounds. */ | |
b77aa1f7 AP |
2100 | if (TREE_CODE (min_value) == INTEGER_CST |
2101 | && tree_int_cst_compare (low, min_value) < 0) | |
eb172681 RS |
2102 | low = min_value; |
2103 | low = fold_convert (type, low); | |
2104 | ||
2105 | /* If the upper bound is greater than the index type's maximum | |
2106 | value, truncate the range bounds. */ | |
b77aa1f7 AP |
2107 | if (TREE_CODE (max_value) == INTEGER_CST |
2108 | && tree_int_cst_compare (high, max_value) > 0) | |
eb172681 RS |
2109 | high = max_value; |
2110 | high = fold_convert (type, high); | |
2111 | } | |
2112 | ||
56cb9733 | 2113 | |
a6c0a76c | 2114 | /* Add this label to the chain. */ |
703ad42b | 2115 | r = ggc_alloc (sizeof (struct case_node)); |
1da68f56 | 2116 | r->low = low; |
a6c0a76c | 2117 | r->high = high; |
57641239 | 2118 | r->code_label = label; |
a6c0a76c | 2119 | r->parent = r->left = NULL; |
7efcb746 PB |
2120 | r->right = head; |
2121 | return r; | |
28d81abb | 2122 | } |
28d81abb | 2123 | \f |
9bb231fd RS |
2124 | /* Maximum number of case bit tests. */ |
2125 | #define MAX_CASE_BIT_TESTS 3 | |
2126 | ||
2127 | /* By default, enable case bit tests on targets with ashlsi3. */ | |
2128 | #ifndef CASE_USE_BIT_TESTS | |
2129 | #define CASE_USE_BIT_TESTS (ashl_optab->handlers[word_mode].insn_code \ | |
2130 | != CODE_FOR_nothing) | |
2131 | #endif | |
2132 | ||
2133 | ||
2134 | /* A case_bit_test represents a set of case nodes that may be | |
2135 | selected from using a bit-wise comparison. HI and LO hold | |
2136 | the integer to be tested against, LABEL contains the label | |
2137 | to jump to upon success and BITS counts the number of case | |
2138 | nodes handled by this test, typically the number of bits | |
2139 | set in HI:LO. */ | |
2140 | ||
2141 | struct case_bit_test | |
2142 | { | |
2143 | HOST_WIDE_INT hi; | |
2144 | HOST_WIDE_INT lo; | |
2145 | rtx label; | |
2146 | int bits; | |
2147 | }; | |
2148 | ||
2149 | /* Determine whether "1 << x" is relatively cheap in word_mode. */ | |
2150 | ||
7e51717c AJ |
2151 | static |
2152 | bool lshift_cheap_p (void) | |
9bb231fd RS |
2153 | { |
2154 | static bool init = false; | |
2155 | static bool cheap = true; | |
2156 | ||
2157 | if (!init) | |
2158 | { | |
2159 | rtx reg = gen_rtx_REG (word_mode, 10000); | |
2160 | int cost = rtx_cost (gen_rtx_ASHIFT (word_mode, const1_rtx, reg), SET); | |
2161 | cheap = cost < COSTS_N_INSNS (3); | |
2162 | init = true; | |
2163 | } | |
2164 | ||
2165 | return cheap; | |
2166 | } | |
2167 | ||
2168 | /* Comparison function for qsort to order bit tests by decreasing | |
2169 | number of case nodes, i.e. the node with the most cases gets | |
2170 | tested first. */ | |
2171 | ||
f667741c SB |
2172 | static int |
2173 | case_bit_test_cmp (const void *p1, const void *p2) | |
9bb231fd RS |
2174 | { |
2175 | const struct case_bit_test *d1 = p1; | |
2176 | const struct case_bit_test *d2 = p2; | |
2177 | ||
2178 | return d2->bits - d1->bits; | |
2179 | } | |
2180 | ||
2181 | /* Expand a switch statement by a short sequence of bit-wise | |
2182 | comparisons. "switch(x)" is effectively converted into | |
2183 | "if ((1 << (x-MINVAL)) & CST)" where CST and MINVAL are | |
2184 | integer constants. | |
2185 | ||
2186 | INDEX_EXPR is the value being switched on, which is of | |
2187 | type INDEX_TYPE. MINVAL is the lowest case value of in | |
2188 | the case nodes, of INDEX_TYPE type, and RANGE is highest | |
2189 | value minus MINVAL, also of type INDEX_TYPE. NODES is | |
2190 | the set of case nodes, and DEFAULT_LABEL is the label to | |
2191 | branch to should none of the cases match. | |
2192 | ||
2193 | There *MUST* be MAX_CASE_BIT_TESTS or less unique case | |
2194 | node targets. */ | |
2195 | ||
2196 | static void | |
46c5ad27 AJ |
2197 | emit_case_bit_tests (tree index_type, tree index_expr, tree minval, |
2198 | tree range, case_node_ptr nodes, rtx default_label) | |
9bb231fd RS |
2199 | { |
2200 | struct case_bit_test test[MAX_CASE_BIT_TESTS]; | |
2201 | enum machine_mode mode; | |
2202 | rtx expr, index, label; | |
2203 | unsigned int i,j,lo,hi; | |
2204 | struct case_node *n; | |
2205 | unsigned int count; | |
2206 | ||
2207 | count = 0; | |
2208 | for (n = nodes; n; n = n->right) | |
2209 | { | |
2210 | label = label_rtx (n->code_label); | |
2211 | for (i = 0; i < count; i++) | |
7efcb746 | 2212 | if (label == test[i].label) |
9bb231fd RS |
2213 | break; |
2214 | ||
2215 | if (i == count) | |
2216 | { | |
41374e13 NS |
2217 | gcc_assert (count < MAX_CASE_BIT_TESTS); |
2218 | test[i].hi = 0; | |
2219 | test[i].lo = 0; | |
9bb231fd RS |
2220 | test[i].label = label; |
2221 | test[i].bits = 1; | |
2222 | count++; | |
2223 | } | |
2224 | else | |
2225 | test[i].bits++; | |
2226 | ||
3244e67d RS |
2227 | lo = tree_low_cst (fold (build2 (MINUS_EXPR, index_type, |
2228 | n->low, minval)), 1); | |
2229 | hi = tree_low_cst (fold (build2 (MINUS_EXPR, index_type, | |
2230 | n->high, minval)), 1); | |
9bb231fd RS |
2231 | for (j = lo; j <= hi; j++) |
2232 | if (j >= HOST_BITS_PER_WIDE_INT) | |
2233 | test[i].hi |= (HOST_WIDE_INT) 1 << (j - HOST_BITS_PER_INT); | |
2234 | else | |
2235 | test[i].lo |= (HOST_WIDE_INT) 1 << j; | |
2236 | } | |
2237 | ||
2238 | qsort (test, count, sizeof(*test), case_bit_test_cmp); | |
2239 | ||
3244e67d RS |
2240 | index_expr = fold (build2 (MINUS_EXPR, index_type, |
2241 | convert (index_type, index_expr), | |
2242 | convert (index_type, minval))); | |
9bb231fd | 2243 | index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0); |
9bb231fd RS |
2244 | do_pending_stack_adjust (); |
2245 | ||
2246 | mode = TYPE_MODE (index_type); | |
2247 | expr = expand_expr (range, NULL_RTX, VOIDmode, 0); | |
2248 | emit_cmp_and_jump_insns (index, expr, GTU, NULL_RTX, mode, 1, | |
2249 | default_label); | |
2250 | ||
2251 | index = convert_to_mode (word_mode, index, 0); | |
2252 | index = expand_binop (word_mode, ashl_optab, const1_rtx, | |
2253 | index, NULL_RTX, 1, OPTAB_WIDEN); | |
2254 | ||
2255 | for (i = 0; i < count; i++) | |
2256 | { | |
2257 | expr = immed_double_const (test[i].lo, test[i].hi, word_mode); | |
2258 | expr = expand_binop (word_mode, and_optab, index, expr, | |
2259 | NULL_RTX, 1, OPTAB_WIDEN); | |
2260 | emit_cmp_and_jump_insns (expr, const0_rtx, NE, NULL_RTX, | |
2261 | word_mode, 1, test[i].label); | |
2262 | } | |
2263 | ||
2264 | emit_jump (default_label); | |
2265 | } | |
ad82abb8 | 2266 | |
41cbdcd0 KH |
2267 | #ifndef HAVE_casesi |
2268 | #define HAVE_casesi 0 | |
2269 | #endif | |
2270 | ||
2271 | #ifndef HAVE_tablejump | |
2272 | #define HAVE_tablejump 0 | |
2273 | #endif | |
2274 | ||
28d81abb | 2275 | /* Terminate a case (Pascal) or switch (C) statement |
9ab0ddd7 | 2276 | in which ORIG_INDEX is the expression to be tested. |
6f9fdf4d JJ |
2277 | If ORIG_TYPE is not NULL, it is the original ORIG_INDEX |
2278 | type as given in the source before any compiler conversions. | |
28d81abb RK |
2279 | Generate the code to test it and jump to the right place. */ |
2280 | ||
2281 | void | |
7efcb746 | 2282 | expand_case (tree exp) |
28d81abb | 2283 | { |
9fb60a0d | 2284 | tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE; |
28d81abb | 2285 | rtx default_label = 0; |
4cfa46c8 | 2286 | struct case_node *n; |
9bb231fd | 2287 | unsigned int count, uniq; |
28d81abb | 2288 | rtx index; |
ca695ac9 | 2289 | rtx table_label; |
28d81abb RK |
2290 | int ncases; |
2291 | rtx *labelvec; | |
eb172681 | 2292 | int i, fail; |
9bb231fd | 2293 | rtx before_case, end, lab; |
ca695ac9 | 2294 | |
7efcb746 PB |
2295 | tree vec = SWITCH_LABELS (exp); |
2296 | tree orig_type = TREE_TYPE (exp); | |
2297 | tree index_expr = SWITCH_COND (exp); | |
2298 | tree index_type = TREE_TYPE (index_expr); | |
2299 | int unsignedp = TYPE_UNSIGNED (index_type); | |
2300 | ||
2301 | /* The insn after which the case dispatch should finally | |
2302 | be emitted. Zero for a dummy. */ | |
2303 | rtx start; | |
2304 | ||
2305 | /* A list of case labels; it is first built as a list and it may then | |
2306 | be rearranged into a nearly balanced binary tree. */ | |
2307 | struct case_node *case_list = 0; | |
2308 | ||
2309 | /* Label to jump to if no case matches. */ | |
4e0148df | 2310 | tree default_label_decl; |
7efcb746 PB |
2311 | |
2312 | /* The switch body is lowered in gimplify.c, we should never have | |
2313 | switches with a non-NULL SWITCH_BODY here. */ | |
41374e13 NS |
2314 | gcc_assert (!SWITCH_BODY (exp)); |
2315 | gcc_assert (SWITCH_LABELS (exp)); | |
03c03770 | 2316 | |
28d81abb RK |
2317 | do_pending_stack_adjust (); |
2318 | ||
2319 | /* An ERROR_MARK occurs for various reasons including invalid data type. */ | |
1b0cb6fc | 2320 | if (index_type != error_mark_node) |
28d81abb | 2321 | { |
4e0148df | 2322 | tree elt; |
4cfa46c8 | 2323 | bitmap label_bitmap; |
eb172681 | 2324 | |
5100d114 KH |
2325 | /* cleanup_tree_cfg removes all SWITCH_EXPR with their index |
2326 | expressions being INTEGER_CST. */ | |
2327 | gcc_assert (TREE_CODE (index_expr) != INTEGER_CST); | |
2328 | ||
4e0148df KH |
2329 | /* The default case is at the end of TREE_VEC. */ |
2330 | elt = TREE_VEC_ELT (vec, TREE_VEC_LENGTH (vec) - 1); | |
2331 | gcc_assert (!CASE_HIGH (elt)); | |
2332 | gcc_assert (!CASE_LOW (elt)); | |
2333 | default_label_decl = CASE_LABEL (elt); | |
2334 | ||
2335 | for (i = TREE_VEC_LENGTH (vec) - 1; --i >= 0; ) | |
2336 | { | |
2337 | elt = TREE_VEC_ELT (vec, i); | |
2338 | gcc_assert (CASE_LOW (elt)); | |
2339 | case_list = add_case_node (case_list, index_type, | |
2340 | CASE_LOW (elt), CASE_HIGH (elt), | |
2341 | CASE_LABEL (elt)); | |
eb172681 RS |
2342 | } |
2343 | ||
2344 | ||
2345 | /* Make sure start points to something that won't need any | |
2346 | transformation before the end of this function. */ | |
2347 | start = get_last_insn (); | |
2348 | if (! NOTE_P (start)) | |
2349 | { | |
2350 | emit_note (NOTE_INSN_DELETED); | |
2351 | start = get_last_insn (); | |
2352 | } | |
41374e13 | 2353 | |
7efcb746 | 2354 | default_label = label_rtx (default_label_decl); |
28d81abb RK |
2355 | |
2356 | before_case = get_last_insn (); | |
2357 | ||
5cfffc4e | 2358 | /* Get upper and lower bounds of case values. */ |
28d81abb | 2359 | |
9bb231fd | 2360 | uniq = 0; |
28d81abb | 2361 | count = 0; |
4cfa46c8 | 2362 | label_bitmap = BITMAP_XMALLOC (); |
7efcb746 | 2363 | for (n = case_list; n; n = n->right) |
28d81abb | 2364 | { |
28d81abb RK |
2365 | /* Count the elements and track the largest and smallest |
2366 | of them (treating them as signed even if they are not). */ | |
2367 | if (count++ == 0) | |
2368 | { | |
2369 | minval = n->low; | |
2370 | maxval = n->high; | |
2371 | } | |
2372 | else | |
2373 | { | |
2374 | if (INT_CST_LT (n->low, minval)) | |
2375 | minval = n->low; | |
2376 | if (INT_CST_LT (maxval, n->high)) | |
2377 | maxval = n->high; | |
2378 | } | |
2379 | /* A range counts double, since it requires two compares. */ | |
2380 | if (! tree_int_cst_equal (n->low, n->high)) | |
2381 | count++; | |
9bb231fd | 2382 | |
4cfa46c8 JL |
2383 | /* If we have not seen this label yet, then increase the |
2384 | number of unique case node targets seen. */ | |
9bb231fd | 2385 | lab = label_rtx (n->code_label); |
4cfa46c8 JL |
2386 | if (!bitmap_bit_p (label_bitmap, CODE_LABEL_NUMBER (lab))) |
2387 | { | |
2388 | bitmap_set_bit (label_bitmap, CODE_LABEL_NUMBER (lab)); | |
2389 | uniq++; | |
2390 | } | |
28d81abb RK |
2391 | } |
2392 | ||
4cfa46c8 JL |
2393 | BITMAP_XFREE (label_bitmap); |
2394 | ||
5372d088 KH |
2395 | /* cleanup_tree_cfg removes all SWITCH_EXPR with a single |
2396 | destination, such as one with a default case only. */ | |
2397 | gcc_assert (count != 0); | |
28d81abb | 2398 | |
5372d088 KH |
2399 | /* Compute span of values. */ |
2400 | range = fold (build2 (MINUS_EXPR, index_type, maxval, minval)); | |
3474db0e | 2401 | |
9bb231fd RS |
2402 | /* Try implementing this switch statement by a short sequence of |
2403 | bit-wise comparisons. However, we let the binary-tree case | |
2404 | below handle constant index expressions. */ | |
5372d088 KH |
2405 | if (CASE_USE_BIT_TESTS |
2406 | && ! TREE_CONSTANT (index_expr) | |
2407 | && compare_tree_int (range, GET_MODE_BITSIZE (word_mode)) < 0 | |
2408 | && compare_tree_int (range, 0) > 0 | |
2409 | && lshift_cheap_p () | |
2410 | && ((uniq == 1 && count >= 3) | |
2411 | || (uniq == 2 && count >= 5) | |
2412 | || (uniq == 3 && count >= 6))) | |
9bb231fd RS |
2413 | { |
2414 | /* Optimize the case where all the case values fit in a | |
2415 | word without having to subtract MINVAL. In this case, | |
2416 | we can optimize away the subtraction. */ | |
2417 | if (compare_tree_int (minval, 0) > 0 | |
2418 | && compare_tree_int (maxval, GET_MODE_BITSIZE (word_mode)) < 0) | |
2419 | { | |
2420 | minval = integer_zero_node; | |
2421 | range = maxval; | |
2422 | } | |
2423 | emit_case_bit_tests (index_type, index_expr, minval, range, | |
7efcb746 | 2424 | case_list, default_label); |
9bb231fd RS |
2425 | } |
2426 | ||
28d81abb RK |
2427 | /* If range of values is much bigger than number of values, |
2428 | make a sequence of conditional branches instead of a dispatch. | |
2429 | If the switch-index is a constant, do it this way | |
2430 | because we can optimize it. */ | |
4f73c5dd | 2431 | |
ad82abb8 | 2432 | else if (count < case_values_threshold () |
9e4b13a7 SB |
2433 | || compare_tree_int (range, |
2434 | (optimize_size ? 3 : 10) * count) > 0 | |
f0c988c8 BS |
2435 | /* RANGE may be signed, and really large ranges will show up |
2436 | as negative numbers. */ | |
2437 | || compare_tree_int (range, 0) < 0 | |
3f6fe18e RK |
2438 | #ifndef ASM_OUTPUT_ADDR_DIFF_ELT |
2439 | || flag_pic | |
2440 | #endif | |
41cbdcd0 KH |
2441 | || TREE_CONSTANT (index_expr) |
2442 | /* If neither casesi or tablejump is available, we can | |
2443 | only go this way. */ | |
2444 | || (!HAVE_casesi && !HAVE_tablejump)) | |
28d81abb | 2445 | { |
37366632 | 2446 | index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0); |
28d81abb RK |
2447 | |
2448 | /* If the index is a short or char that we do not have | |
2449 | an insn to handle comparisons directly, convert it to | |
2450 | a full integer now, rather than letting each comparison | |
2451 | generate the conversion. */ | |
2452 | ||
2453 | if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT | |
ef89d648 | 2454 | && ! have_insn_for (COMPARE, GET_MODE (index))) |
28d81abb RK |
2455 | { |
2456 | enum machine_mode wider_mode; | |
2457 | for (wider_mode = GET_MODE (index); wider_mode != VOIDmode; | |
2458 | wider_mode = GET_MODE_WIDER_MODE (wider_mode)) | |
ef89d648 | 2459 | if (have_insn_for (COMPARE, wider_mode)) |
28d81abb RK |
2460 | { |
2461 | index = convert_to_mode (wider_mode, index, unsignedp); | |
2462 | break; | |
2463 | } | |
2464 | } | |
2465 | ||
28d81abb RK |
2466 | do_pending_stack_adjust (); |
2467 | ||
3c0cb5de | 2468 | if (MEM_P (index)) |
28d81abb | 2469 | index = copy_to_reg (index); |
28d81abb | 2470 | |
b2c5a1e9 KH |
2471 | /* We generate a binary decision tree to select the |
2472 | appropriate target code. This is done as follows: | |
5100d114 KH |
2473 | |
2474 | The list of cases is rearranged into a binary tree, | |
2475 | nearly optimal assuming equal probability for each case. | |
2476 | ||
2477 | The tree is transformed into RTL, eliminating | |
2478 | redundant test conditions at the same time. | |
2479 | ||
2480 | If program flow could reach the end of the | |
2481 | decision tree an unconditional jump to the | |
2482 | default code is emitted. */ | |
2483 | ||
2484 | use_cost_table | |
2485 | = (TREE_CODE (orig_type) != ENUMERAL_TYPE | |
2486 | && estimate_case_costs (case_list)); | |
2487 | balance_case_nodes (&case_list, NULL); | |
2488 | emit_case_nodes (index, case_list, default_label, index_type); | |
2489 | emit_jump (default_label); | |
28d81abb RK |
2490 | } |
2491 | else | |
2492 | { | |
100e3acb | 2493 | table_label = gen_label_rtx (); |
ad82abb8 ZW |
2494 | if (! try_casesi (index_type, index_expr, minval, range, |
2495 | table_label, default_label)) | |
28d81abb | 2496 | { |
41374e13 | 2497 | bool ok; |
165b54c3 | 2498 | index_type = integer_type_node; |
1ff37128 | 2499 | |
786de7eb | 2500 | /* Index jumptables from zero for suitable values of |
1ff37128 | 2501 | minval to avoid a subtraction. */ |
786de7eb KH |
2502 | if (! optimize_size |
2503 | && compare_tree_int (minval, 0) > 0 | |
2504 | && compare_tree_int (minval, 3) < 0) | |
2505 | { | |
2506 | minval = integer_zero_node; | |
2507 | range = maxval; | |
2508 | } | |
1ff37128 | 2509 | |
41374e13 NS |
2510 | ok = try_tablejump (index_type, index_expr, minval, range, |
2511 | table_label, default_label); | |
2512 | gcc_assert (ok); | |
28d81abb | 2513 | } |
786de7eb | 2514 | |
28d81abb RK |
2515 | /* Get table of labels to jump to, in order of case index. */ |
2516 | ||
1ff37128 | 2517 | ncases = tree_low_cst (range, 0) + 1; |
703ad42b KG |
2518 | labelvec = alloca (ncases * sizeof (rtx)); |
2519 | memset (labelvec, 0, ncases * sizeof (rtx)); | |
28d81abb | 2520 | |
7efcb746 | 2521 | for (n = case_list; n; n = n->right) |
28d81abb | 2522 | { |
2d9d49e4 OH |
2523 | /* Compute the low and high bounds relative to the minimum |
2524 | value since that should fit in a HOST_WIDE_INT while the | |
2525 | actual values may not. */ | |
2526 | HOST_WIDE_INT i_low | |
3244e67d RS |
2527 | = tree_low_cst (fold (build2 (MINUS_EXPR, index_type, |
2528 | n->low, minval)), 1); | |
2d9d49e4 | 2529 | HOST_WIDE_INT i_high |
3244e67d RS |
2530 | = tree_low_cst (fold (build2 (MINUS_EXPR, index_type, |
2531 | n->high, minval)), 1); | |
2d9d49e4 OH |
2532 | HOST_WIDE_INT i; |
2533 | ||
2534 | for (i = i_low; i <= i_high; i ++) | |
2535 | labelvec[i] | |
2536 | = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label)); | |
28d81abb RK |
2537 | } |
2538 | ||
2539 | /* Fill in the gaps with the default. */ | |
2540 | for (i = 0; i < ncases; i++) | |
2541 | if (labelvec[i] == 0) | |
38a448ca | 2542 | labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label); |
28d81abb | 2543 | |
f9da5064 | 2544 | /* Output the table. */ |
28d81abb RK |
2545 | emit_label (table_label); |
2546 | ||
18543a22 | 2547 | if (CASE_VECTOR_PC_RELATIVE || flag_pic) |
38a448ca RH |
2548 | emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE, |
2549 | gen_rtx_LABEL_REF (Pmode, table_label), | |
33f7f353 | 2550 | gen_rtvec_v (ncases, labelvec), |
4381f7c2 | 2551 | const0_rtx, const0_rtx)); |
28d81abb | 2552 | else |
38a448ca RH |
2553 | emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE, |
2554 | gen_rtvec_v (ncases, labelvec))); | |
28d81abb | 2555 | |
6be85b25 | 2556 | /* Record no drop-through after the table. */ |
28d81abb | 2557 | emit_barrier (); |
28d81abb RK |
2558 | } |
2559 | ||
2270623a JM |
2560 | before_case = NEXT_INSN (before_case); |
2561 | end = get_last_insn (); | |
41374e13 NS |
2562 | fail = squeeze_notes (&before_case, &end); |
2563 | gcc_assert (!fail); | |
7efcb746 | 2564 | reorder_insns (before_case, end, start); |
28d81abb | 2565 | } |
1b0cb6fc | 2566 | |
28d81abb RK |
2567 | free_temp_slots (); |
2568 | } | |
2569 | ||
2570 | /* Generate code to jump to LABEL if OP1 and OP2 are equal. */ | |
2571 | ||
2572 | static void | |
46c5ad27 | 2573 | do_jump_if_equal (rtx op1, rtx op2, rtx label, int unsignedp) |
28d81abb | 2574 | { |
d43e0b7d | 2575 | if (GET_CODE (op1) == CONST_INT && GET_CODE (op2) == CONST_INT) |
28d81abb | 2576 | { |
d51d146f | 2577 | if (op1 == op2) |
28d81abb RK |
2578 | emit_jump (label); |
2579 | } | |
2580 | else | |
d43e0b7d RK |
2581 | emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, |
2582 | (GET_MODE (op1) == VOIDmode | |
2583 | ? GET_MODE (op2) : GET_MODE (op1)), | |
2584 | unsignedp, label); | |
28d81abb RK |
2585 | } |
2586 | \f | |
2587 | /* Not all case values are encountered equally. This function | |
2588 | uses a heuristic to weight case labels, in cases where that | |
2589 | looks like a reasonable thing to do. | |
2590 | ||
2591 | Right now, all we try to guess is text, and we establish the | |
2592 | following weights: | |
2593 | ||
2594 | chars above space: 16 | |
2595 | digits: 16 | |
2596 | default: 12 | |
2597 | space, punct: 8 | |
2598 | tab: 4 | |
2599 | newline: 2 | |
2600 | other "\" chars: 1 | |
2601 | remaining chars: 0 | |
2602 | ||
2603 | If we find any cases in the switch that are not either -1 or in the range | |
2604 | of valid ASCII characters, or are control characters other than those | |
2605 | commonly used with "\", don't treat this switch scanning text. | |
2606 | ||
2607 | Return 1 if these nodes are suitable for cost estimation, otherwise | |
2608 | return 0. */ | |
2609 | ||
2610 | static int | |
46c5ad27 | 2611 | estimate_case_costs (case_node_ptr node) |
28d81abb | 2612 | { |
f2d1f0ba | 2613 | tree min_ascii = integer_minus_one_node; |
4a90aeeb | 2614 | tree max_ascii = convert (TREE_TYPE (node->high), |
7d60be94 | 2615 | build_int_cst (NULL_TREE, 127)); |
28d81abb RK |
2616 | case_node_ptr n; |
2617 | int i; | |
2618 | ||
2619 | /* If we haven't already made the cost table, make it now. Note that the | |
2620 | lower bound of the table is -1, not zero. */ | |
2621 | ||
2a2137c4 | 2622 | if (! cost_table_initialized) |
28d81abb | 2623 | { |
2a2137c4 | 2624 | cost_table_initialized = 1; |
28d81abb RK |
2625 | |
2626 | for (i = 0; i < 128; i++) | |
2627 | { | |
e9a780ec | 2628 | if (ISALNUM (i)) |
2a2137c4 | 2629 | COST_TABLE (i) = 16; |
e9a780ec | 2630 | else if (ISPUNCT (i)) |
2a2137c4 | 2631 | COST_TABLE (i) = 8; |
e9a780ec | 2632 | else if (ISCNTRL (i)) |
2a2137c4 | 2633 | COST_TABLE (i) = -1; |
28d81abb RK |
2634 | } |
2635 | ||
2a2137c4 RH |
2636 | COST_TABLE (' ') = 8; |
2637 | COST_TABLE ('\t') = 4; | |
2638 | COST_TABLE ('\0') = 4; | |
2639 | COST_TABLE ('\n') = 2; | |
2640 | COST_TABLE ('\f') = 1; | |
2641 | COST_TABLE ('\v') = 1; | |
2642 | COST_TABLE ('\b') = 1; | |
28d81abb RK |
2643 | } |
2644 | ||
2645 | /* See if all the case expressions look like text. It is text if the | |
2646 | constant is >= -1 and the highest constant is <= 127. Do all comparisons | |
2647 | as signed arithmetic since we don't want to ever access cost_table with a | |
2648 | value less than -1. Also check that none of the constants in a range | |
2649 | are strange control characters. */ | |
2650 | ||
2651 | for (n = node; n; n = n->right) | |
2652 | { | |
2653 | if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high)) | |
2654 | return 0; | |
2655 | ||
05bccae2 RK |
2656 | for (i = (HOST_WIDE_INT) TREE_INT_CST_LOW (n->low); |
2657 | i <= (HOST_WIDE_INT) TREE_INT_CST_LOW (n->high); i++) | |
2a2137c4 | 2658 | if (COST_TABLE (i) < 0) |
28d81abb RK |
2659 | return 0; |
2660 | } | |
2661 | ||
2662 | /* All interesting values are within the range of interesting | |
2663 | ASCII characters. */ | |
2664 | return 1; | |
2665 | } | |
2666 | ||
28d81abb RK |
2667 | /* Take an ordered list of case nodes |
2668 | and transform them into a near optimal binary tree, | |
6dc42e49 | 2669 | on the assumption that any target code selection value is as |
28d81abb RK |
2670 | likely as any other. |
2671 | ||
2672 | The transformation is performed by splitting the ordered | |
2673 | list into two equal sections plus a pivot. The parts are | |
2674 | then attached to the pivot as left and right branches. Each | |
38e01259 | 2675 | branch is then transformed recursively. */ |
28d81abb RK |
2676 | |
2677 | static void | |
46c5ad27 | 2678 | balance_case_nodes (case_node_ptr *head, case_node_ptr parent) |
28d81abb | 2679 | { |
b3694847 | 2680 | case_node_ptr np; |
28d81abb RK |
2681 | |
2682 | np = *head; | |
2683 | if (np) | |
2684 | { | |
2685 | int cost = 0; | |
2686 | int i = 0; | |
2687 | int ranges = 0; | |
b3694847 | 2688 | case_node_ptr *npp; |
28d81abb RK |
2689 | case_node_ptr left; |
2690 | ||
2691 | /* Count the number of entries on branch. Also count the ranges. */ | |
2692 | ||
2693 | while (np) | |
2694 | { | |
2695 | if (!tree_int_cst_equal (np->low, np->high)) | |
2696 | { | |
2697 | ranges++; | |
2698 | if (use_cost_table) | |
2a2137c4 | 2699 | cost += COST_TABLE (TREE_INT_CST_LOW (np->high)); |
28d81abb RK |
2700 | } |
2701 | ||
2702 | if (use_cost_table) | |
2a2137c4 | 2703 | cost += COST_TABLE (TREE_INT_CST_LOW (np->low)); |
28d81abb RK |
2704 | |
2705 | i++; | |
2706 | np = np->right; | |
2707 | } | |
2708 | ||
2709 | if (i > 2) | |
2710 | { | |
2711 | /* Split this list if it is long enough for that to help. */ | |
2712 | npp = head; | |
2713 | left = *npp; | |
2714 | if (use_cost_table) | |
2715 | { | |
2716 | /* Find the place in the list that bisects the list's total cost, | |
2717 | Here I gets half the total cost. */ | |
2718 | int n_moved = 0; | |
2719 | i = (cost + 1) / 2; | |
2720 | while (1) | |
2721 | { | |
2722 | /* Skip nodes while their cost does not reach that amount. */ | |
2723 | if (!tree_int_cst_equal ((*npp)->low, (*npp)->high)) | |
2a2137c4 RH |
2724 | i -= COST_TABLE (TREE_INT_CST_LOW ((*npp)->high)); |
2725 | i -= COST_TABLE (TREE_INT_CST_LOW ((*npp)->low)); | |
28d81abb RK |
2726 | if (i <= 0) |
2727 | break; | |
2728 | npp = &(*npp)->right; | |
2729 | n_moved += 1; | |
2730 | } | |
2731 | if (n_moved == 0) | |
2732 | { | |
2733 | /* Leave this branch lopsided, but optimize left-hand | |
2734 | side and fill in `parent' fields for right-hand side. */ | |
2735 | np = *head; | |
2736 | np->parent = parent; | |
2737 | balance_case_nodes (&np->left, np); | |
2738 | for (; np->right; np = np->right) | |
2739 | np->right->parent = np; | |
2740 | return; | |
2741 | } | |
2742 | } | |
2743 | /* If there are just three nodes, split at the middle one. */ | |
2744 | else if (i == 3) | |
2745 | npp = &(*npp)->right; | |
2746 | else | |
2747 | { | |
2748 | /* Find the place in the list that bisects the list's total cost, | |
2749 | where ranges count as 2. | |
2750 | Here I gets half the total cost. */ | |
2751 | i = (i + ranges + 1) / 2; | |
2752 | while (1) | |
2753 | { | |
2754 | /* Skip nodes while their cost does not reach that amount. */ | |
2755 | if (!tree_int_cst_equal ((*npp)->low, (*npp)->high)) | |
2756 | i--; | |
2757 | i--; | |
2758 | if (i <= 0) | |
2759 | break; | |
2760 | npp = &(*npp)->right; | |
2761 | } | |
2762 | } | |
2763 | *head = np = *npp; | |
2764 | *npp = 0; | |
2765 | np->parent = parent; | |
2766 | np->left = left; | |
2767 | ||
2768 | /* Optimize each of the two split parts. */ | |
2769 | balance_case_nodes (&np->left, np); | |
2770 | balance_case_nodes (&np->right, np); | |
2771 | } | |
2772 | else | |
2773 | { | |
2774 | /* Else leave this branch as one level, | |
2775 | but fill in `parent' fields. */ | |
2776 | np = *head; | |
2777 | np->parent = parent; | |
2778 | for (; np->right; np = np->right) | |
2779 | np->right->parent = np; | |
2780 | } | |
2781 | } | |
2782 | } | |
2783 | \f | |
2784 | /* Search the parent sections of the case node tree | |
2785 | to see if a test for the lower bound of NODE would be redundant. | |
2786 | INDEX_TYPE is the type of the index expression. | |
2787 | ||
2788 | The instructions to generate the case decision tree are | |
2789 | output in the same order as nodes are processed so it is | |
2790 | known that if a parent node checks the range of the current | |
2791 | node minus one that the current node is bounded at its lower | |
2792 | span. Thus the test would be redundant. */ | |
2793 | ||
2794 | static int | |
46c5ad27 | 2795 | node_has_low_bound (case_node_ptr node, tree index_type) |
28d81abb RK |
2796 | { |
2797 | tree low_minus_one; | |
2798 | case_node_ptr pnode; | |
2799 | ||
2800 | /* If the lower bound of this node is the lowest value in the index type, | |
2801 | we need not test it. */ | |
2802 | ||
2803 | if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type))) | |
2804 | return 1; | |
2805 | ||
2806 | /* If this node has a left branch, the value at the left must be less | |
2807 | than that at this node, so it cannot be bounded at the bottom and | |
2808 | we need not bother testing any further. */ | |
2809 | ||
2810 | if (node->left) | |
2811 | return 0; | |
2812 | ||
3244e67d RS |
2813 | low_minus_one = fold (build2 (MINUS_EXPR, TREE_TYPE (node->low), |
2814 | node->low, integer_one_node)); | |
28d81abb RK |
2815 | |
2816 | /* If the subtraction above overflowed, we can't verify anything. | |
2817 | Otherwise, look for a parent that tests our value - 1. */ | |
2818 | ||
2819 | if (! tree_int_cst_lt (low_minus_one, node->low)) | |
2820 | return 0; | |
2821 | ||
2822 | for (pnode = node->parent; pnode; pnode = pnode->parent) | |
2823 | if (tree_int_cst_equal (low_minus_one, pnode->high)) | |
2824 | return 1; | |
2825 | ||
2826 | return 0; | |
2827 | } | |
2828 | ||
2829 | /* Search the parent sections of the case node tree | |
2830 | to see if a test for the upper bound of NODE would be redundant. | |
2831 | INDEX_TYPE is the type of the index expression. | |
2832 | ||
2833 | The instructions to generate the case decision tree are | |
2834 | output in the same order as nodes are processed so it is | |
2835 | known that if a parent node checks the range of the current | |
2836 | node plus one that the current node is bounded at its upper | |
2837 | span. Thus the test would be redundant. */ | |
2838 | ||
2839 | static int | |
46c5ad27 | 2840 | node_has_high_bound (case_node_ptr node, tree index_type) |
28d81abb RK |
2841 | { |
2842 | tree high_plus_one; | |
2843 | case_node_ptr pnode; | |
2844 | ||
e1ee5cdc RH |
2845 | /* If there is no upper bound, obviously no test is needed. */ |
2846 | ||
2847 | if (TYPE_MAX_VALUE (index_type) == NULL) | |
2848 | return 1; | |
2849 | ||
28d81abb RK |
2850 | /* If the upper bound of this node is the highest value in the type |
2851 | of the index expression, we need not test against it. */ | |
2852 | ||
2853 | if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type))) | |
2854 | return 1; | |
2855 | ||
2856 | /* If this node has a right branch, the value at the right must be greater | |
2857 | than that at this node, so it cannot be bounded at the top and | |
2858 | we need not bother testing any further. */ | |
2859 | ||
2860 | if (node->right) | |
2861 | return 0; | |
2862 | ||
3244e67d RS |
2863 | high_plus_one = fold (build2 (PLUS_EXPR, TREE_TYPE (node->high), |
2864 | node->high, integer_one_node)); | |
28d81abb RK |
2865 | |
2866 | /* If the addition above overflowed, we can't verify anything. | |
2867 | Otherwise, look for a parent that tests our value + 1. */ | |
2868 | ||
2869 | if (! tree_int_cst_lt (node->high, high_plus_one)) | |
2870 | return 0; | |
2871 | ||
2872 | for (pnode = node->parent; pnode; pnode = pnode->parent) | |
2873 | if (tree_int_cst_equal (high_plus_one, pnode->low)) | |
2874 | return 1; | |
2875 | ||
2876 | return 0; | |
2877 | } | |
2878 | ||
2879 | /* Search the parent sections of the | |
2880 | case node tree to see if both tests for the upper and lower | |
2881 | bounds of NODE would be redundant. */ | |
2882 | ||
2883 | static int | |
46c5ad27 | 2884 | node_is_bounded (case_node_ptr node, tree index_type) |
28d81abb RK |
2885 | { |
2886 | return (node_has_low_bound (node, index_type) | |
2887 | && node_has_high_bound (node, index_type)); | |
2888 | } | |
28d81abb RK |
2889 | \f |
2890 | /* Emit step-by-step code to select a case for the value of INDEX. | |
2891 | The thus generated decision tree follows the form of the | |
2892 | case-node binary tree NODE, whose nodes represent test conditions. | |
2893 | INDEX_TYPE is the type of the index of the switch. | |
2894 | ||
2895 | Care is taken to prune redundant tests from the decision tree | |
2896 | by detecting any boundary conditions already checked by | |
2897 | emitted rtx. (See node_has_high_bound, node_has_low_bound | |
2898 | and node_is_bounded, above.) | |
2899 | ||
2900 | Where the test conditions can be shown to be redundant we emit | |
2901 | an unconditional jump to the target code. As a further | |
2902 | optimization, the subordinates of a tree node are examined to | |
2903 | check for bounded nodes. In this case conditional and/or | |
2904 | unconditional jumps as a result of the boundary check for the | |
2905 | current node are arranged to target the subordinates associated | |
38e01259 | 2906 | code for out of bound conditions on the current node. |
28d81abb | 2907 | |
f72aed24 | 2908 | We can assume that when control reaches the code generated here, |
28d81abb RK |
2909 | the index value has already been compared with the parents |
2910 | of this node, and determined to be on the same side of each parent | |
2911 | as this node is. Thus, if this node tests for the value 51, | |
2912 | and a parent tested for 52, we don't need to consider | |
2913 | the possibility of a value greater than 51. If another parent | |
2914 | tests for the value 50, then this node need not test anything. */ | |
2915 | ||
2916 | static void | |
46c5ad27 AJ |
2917 | emit_case_nodes (rtx index, case_node_ptr node, rtx default_label, |
2918 | tree index_type) | |
28d81abb RK |
2919 | { |
2920 | /* If INDEX has an unsigned type, we must make unsigned branches. */ | |
8df83eae | 2921 | int unsignedp = TYPE_UNSIGNED (index_type); |
28d81abb | 2922 | enum machine_mode mode = GET_MODE (index); |
69107307 | 2923 | enum machine_mode imode = TYPE_MODE (index_type); |
28d81abb RK |
2924 | |
2925 | /* See if our parents have already tested everything for us. | |
2926 | If they have, emit an unconditional jump for this node. */ | |
2927 | if (node_is_bounded (node, index_type)) | |
2928 | emit_jump (label_rtx (node->code_label)); | |
2929 | ||
2930 | else if (tree_int_cst_equal (node->low, node->high)) | |
2931 | { | |
2932 | /* Node is single valued. First see if the index expression matches | |
0f41302f | 2933 | this node and then check our children, if any. */ |
28d81abb | 2934 | |
69107307 AO |
2935 | do_jump_if_equal (index, |
2936 | convert_modes (mode, imode, | |
2937 | expand_expr (node->low, NULL_RTX, | |
2938 | VOIDmode, 0), | |
2939 | unsignedp), | |
28d81abb RK |
2940 | label_rtx (node->code_label), unsignedp); |
2941 | ||
2942 | if (node->right != 0 && node->left != 0) | |
2943 | { | |
2944 | /* This node has children on both sides. | |
2945 | Dispatch to one side or the other | |
2946 | by comparing the index value with this node's value. | |
2947 | If one subtree is bounded, check that one first, | |
2948 | so we can avoid real branches in the tree. */ | |
2949 | ||
2950 | if (node_is_bounded (node->right, index_type)) | |
2951 | { | |
4381f7c2 | 2952 | emit_cmp_and_jump_insns (index, |
69107307 AO |
2953 | convert_modes |
2954 | (mode, imode, | |
2955 | expand_expr (node->high, NULL_RTX, | |
2956 | VOIDmode, 0), | |
2957 | unsignedp), | |
d43e0b7d | 2958 | GT, NULL_RTX, mode, unsignedp, |
4381f7c2 | 2959 | label_rtx (node->right->code_label)); |
28d81abb RK |
2960 | emit_case_nodes (index, node->left, default_label, index_type); |
2961 | } | |
2962 | ||
2963 | else if (node_is_bounded (node->left, index_type)) | |
2964 | { | |
4381f7c2 | 2965 | emit_cmp_and_jump_insns (index, |
69107307 AO |
2966 | convert_modes |
2967 | (mode, imode, | |
2968 | expand_expr (node->high, NULL_RTX, | |
2969 | VOIDmode, 0), | |
2970 | unsignedp), | |
d43e0b7d | 2971 | LT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 2972 | label_rtx (node->left->code_label)); |
28d81abb RK |
2973 | emit_case_nodes (index, node->right, default_label, index_type); |
2974 | } | |
2975 | ||
43a21dfc KH |
2976 | /* If both children are single-valued cases with no |
2977 | children, finish up all the work. This way, we can save | |
2978 | one ordered comparison. */ | |
2979 | else if (tree_int_cst_equal (node->right->low, node->right->high) | |
2980 | && node->right->left == 0 | |
2981 | && node->right->right == 0 | |
2982 | && tree_int_cst_equal (node->left->low, node->left->high) | |
2983 | && node->left->left == 0 | |
2984 | && node->left->right == 0) | |
2985 | { | |
2986 | /* Neither node is bounded. First distinguish the two sides; | |
2987 | then emit the code for one side at a time. */ | |
2988 | ||
2989 | /* See if the value matches what the right hand side | |
2990 | wants. */ | |
2991 | do_jump_if_equal (index, | |
2992 | convert_modes (mode, imode, | |
2993 | expand_expr (node->right->low, | |
2994 | NULL_RTX, | |
2995 | VOIDmode, 0), | |
2996 | unsignedp), | |
2997 | label_rtx (node->right->code_label), | |
2998 | unsignedp); | |
2999 | ||
3000 | /* See if the value matches what the left hand side | |
3001 | wants. */ | |
3002 | do_jump_if_equal (index, | |
3003 | convert_modes (mode, imode, | |
3004 | expand_expr (node->left->low, | |
3005 | NULL_RTX, | |
3006 | VOIDmode, 0), | |
3007 | unsignedp), | |
3008 | label_rtx (node->left->code_label), | |
3009 | unsignedp); | |
3010 | } | |
3011 | ||
28d81abb RK |
3012 | else |
3013 | { | |
3014 | /* Neither node is bounded. First distinguish the two sides; | |
3015 | then emit the code for one side at a time. */ | |
3016 | ||
4381f7c2 | 3017 | tree test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE); |
28d81abb RK |
3018 | |
3019 | /* See if the value is on the right. */ | |
4381f7c2 | 3020 | emit_cmp_and_jump_insns (index, |
69107307 AO |
3021 | convert_modes |
3022 | (mode, imode, | |
3023 | expand_expr (node->high, NULL_RTX, | |
3024 | VOIDmode, 0), | |
3025 | unsignedp), | |
d43e0b7d | 3026 | GT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3027 | label_rtx (test_label)); |
28d81abb RK |
3028 | |
3029 | /* Value must be on the left. | |
3030 | Handle the left-hand subtree. */ | |
3031 | emit_case_nodes (index, node->left, default_label, index_type); | |
3032 | /* If left-hand subtree does nothing, | |
3033 | go to default. */ | |
165b54c3 | 3034 | emit_jump (default_label); |
28d81abb RK |
3035 | |
3036 | /* Code branches here for the right-hand subtree. */ | |
3037 | expand_label (test_label); | |
3038 | emit_case_nodes (index, node->right, default_label, index_type); | |
3039 | } | |
3040 | } | |
3041 | ||
3042 | else if (node->right != 0 && node->left == 0) | |
3043 | { | |
3044 | /* Here we have a right child but no left so we issue conditional | |
3045 | branch to default and process the right child. | |
3046 | ||
3047 | Omit the conditional branch to default if we it avoid only one | |
3048 | right child; it costs too much space to save so little time. */ | |
3049 | ||
de14fd73 | 3050 | if (node->right->right || node->right->left |
28d81abb RK |
3051 | || !tree_int_cst_equal (node->right->low, node->right->high)) |
3052 | { | |
3053 | if (!node_has_low_bound (node, index_type)) | |
3054 | { | |
4381f7c2 | 3055 | emit_cmp_and_jump_insns (index, |
69107307 AO |
3056 | convert_modes |
3057 | (mode, imode, | |
3058 | expand_expr (node->high, NULL_RTX, | |
3059 | VOIDmode, 0), | |
3060 | unsignedp), | |
d43e0b7d | 3061 | LT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3062 | default_label); |
28d81abb RK |
3063 | } |
3064 | ||
3065 | emit_case_nodes (index, node->right, default_label, index_type); | |
3066 | } | |
3067 | else | |
3068 | /* We cannot process node->right normally | |
3069 | since we haven't ruled out the numbers less than | |
3070 | this node's value. So handle node->right explicitly. */ | |
3071 | do_jump_if_equal (index, | |
69107307 AO |
3072 | convert_modes |
3073 | (mode, imode, | |
3074 | expand_expr (node->right->low, NULL_RTX, | |
3075 | VOIDmode, 0), | |
3076 | unsignedp), | |
28d81abb RK |
3077 | label_rtx (node->right->code_label), unsignedp); |
3078 | } | |
3079 | ||
3080 | else if (node->right == 0 && node->left != 0) | |
3081 | { | |
3082 | /* Just one subtree, on the left. */ | |
4381f7c2 | 3083 | if (node->left->left || node->left->right |
28d81abb RK |
3084 | || !tree_int_cst_equal (node->left->low, node->left->high)) |
3085 | { | |
3086 | if (!node_has_high_bound (node, index_type)) | |
3087 | { | |
69107307 AO |
3088 | emit_cmp_and_jump_insns (index, |
3089 | convert_modes | |
3090 | (mode, imode, | |
3091 | expand_expr (node->high, NULL_RTX, | |
3092 | VOIDmode, 0), | |
3093 | unsignedp), | |
d43e0b7d | 3094 | GT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3095 | default_label); |
28d81abb RK |
3096 | } |
3097 | ||
3098 | emit_case_nodes (index, node->left, default_label, index_type); | |
3099 | } | |
3100 | else | |
3101 | /* We cannot process node->left normally | |
3102 | since we haven't ruled out the numbers less than | |
3103 | this node's value. So handle node->left explicitly. */ | |
3104 | do_jump_if_equal (index, | |
69107307 AO |
3105 | convert_modes |
3106 | (mode, imode, | |
3107 | expand_expr (node->left->low, NULL_RTX, | |
3108 | VOIDmode, 0), | |
3109 | unsignedp), | |
28d81abb RK |
3110 | label_rtx (node->left->code_label), unsignedp); |
3111 | } | |
3112 | } | |
3113 | else | |
3114 | { | |
3115 | /* Node is a range. These cases are very similar to those for a single | |
3116 | value, except that we do not start by testing whether this node | |
3117 | is the one to branch to. */ | |
3118 | ||
3119 | if (node->right != 0 && node->left != 0) | |
3120 | { | |
3121 | /* Node has subtrees on both sides. | |
3122 | If the right-hand subtree is bounded, | |
3123 | test for it first, since we can go straight there. | |
3124 | Otherwise, we need to make a branch in the control structure, | |
3125 | then handle the two subtrees. */ | |
3126 | tree test_label = 0; | |
3127 | ||
28d81abb RK |
3128 | if (node_is_bounded (node->right, index_type)) |
3129 | /* Right hand node is fully bounded so we can eliminate any | |
3130 | testing and branch directly to the target code. */ | |
69107307 AO |
3131 | emit_cmp_and_jump_insns (index, |
3132 | convert_modes | |
3133 | (mode, imode, | |
3134 | expand_expr (node->high, NULL_RTX, | |
3135 | VOIDmode, 0), | |
3136 | unsignedp), | |
d43e0b7d | 3137 | GT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3138 | label_rtx (node->right->code_label)); |
28d81abb RK |
3139 | else |
3140 | { | |
3141 | /* Right hand node requires testing. | |
3142 | Branch to a label where we will handle it later. */ | |
3143 | ||
3144 | test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE); | |
4381f7c2 | 3145 | emit_cmp_and_jump_insns (index, |
69107307 AO |
3146 | convert_modes |
3147 | (mode, imode, | |
3148 | expand_expr (node->high, NULL_RTX, | |
3149 | VOIDmode, 0), | |
3150 | unsignedp), | |
d43e0b7d | 3151 | GT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3152 | label_rtx (test_label)); |
28d81abb RK |
3153 | } |
3154 | ||
3155 | /* Value belongs to this node or to the left-hand subtree. */ | |
3156 | ||
69107307 AO |
3157 | emit_cmp_and_jump_insns (index, |
3158 | convert_modes | |
3159 | (mode, imode, | |
3160 | expand_expr (node->low, NULL_RTX, | |
3161 | VOIDmode, 0), | |
3162 | unsignedp), | |
d43e0b7d | 3163 | GE, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3164 | label_rtx (node->code_label)); |
28d81abb RK |
3165 | |
3166 | /* Handle the left-hand subtree. */ | |
3167 | emit_case_nodes (index, node->left, default_label, index_type); | |
3168 | ||
3169 | /* If right node had to be handled later, do that now. */ | |
3170 | ||
3171 | if (test_label) | |
3172 | { | |
3173 | /* If the left-hand subtree fell through, | |
3174 | don't let it fall into the right-hand subtree. */ | |
165b54c3 | 3175 | emit_jump (default_label); |
28d81abb RK |
3176 | |
3177 | expand_label (test_label); | |
3178 | emit_case_nodes (index, node->right, default_label, index_type); | |
3179 | } | |
3180 | } | |
3181 | ||
3182 | else if (node->right != 0 && node->left == 0) | |
3183 | { | |
3184 | /* Deal with values to the left of this node, | |
3185 | if they are possible. */ | |
3186 | if (!node_has_low_bound (node, index_type)) | |
3187 | { | |
4381f7c2 | 3188 | emit_cmp_and_jump_insns (index, |
69107307 AO |
3189 | convert_modes |
3190 | (mode, imode, | |
3191 | expand_expr (node->low, NULL_RTX, | |
3192 | VOIDmode, 0), | |
3193 | unsignedp), | |
d43e0b7d | 3194 | LT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3195 | default_label); |
28d81abb RK |
3196 | } |
3197 | ||
3198 | /* Value belongs to this node or to the right-hand subtree. */ | |
3199 | ||
69107307 AO |
3200 | emit_cmp_and_jump_insns (index, |
3201 | convert_modes | |
3202 | (mode, imode, | |
3203 | expand_expr (node->high, NULL_RTX, | |
3204 | VOIDmode, 0), | |
3205 | unsignedp), | |
d43e0b7d | 3206 | LE, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3207 | label_rtx (node->code_label)); |
28d81abb RK |
3208 | |
3209 | emit_case_nodes (index, node->right, default_label, index_type); | |
3210 | } | |
3211 | ||
3212 | else if (node->right == 0 && node->left != 0) | |
3213 | { | |
3214 | /* Deal with values to the right of this node, | |
3215 | if they are possible. */ | |
3216 | if (!node_has_high_bound (node, index_type)) | |
3217 | { | |
4381f7c2 | 3218 | emit_cmp_and_jump_insns (index, |
69107307 AO |
3219 | convert_modes |
3220 | (mode, imode, | |
3221 | expand_expr (node->high, NULL_RTX, | |
3222 | VOIDmode, 0), | |
3223 | unsignedp), | |
d43e0b7d | 3224 | GT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3225 | default_label); |
28d81abb RK |
3226 | } |
3227 | ||
3228 | /* Value belongs to this node or to the left-hand subtree. */ | |
3229 | ||
4381f7c2 | 3230 | emit_cmp_and_jump_insns (index, |
69107307 AO |
3231 | convert_modes |
3232 | (mode, imode, | |
3233 | expand_expr (node->low, NULL_RTX, | |
3234 | VOIDmode, 0), | |
3235 | unsignedp), | |
d43e0b7d | 3236 | GE, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3237 | label_rtx (node->code_label)); |
28d81abb RK |
3238 | |
3239 | emit_case_nodes (index, node->left, default_label, index_type); | |
3240 | } | |
3241 | ||
3242 | else | |
3243 | { | |
3244 | /* Node has no children so we check low and high bounds to remove | |
3245 | redundant tests. Only one of the bounds can exist, | |
3246 | since otherwise this node is bounded--a case tested already. */ | |
923cbdc3 JH |
3247 | int high_bound = node_has_high_bound (node, index_type); |
3248 | int low_bound = node_has_low_bound (node, index_type); | |
28d81abb | 3249 | |
923cbdc3 | 3250 | if (!high_bound && low_bound) |
28d81abb | 3251 | { |
4381f7c2 | 3252 | emit_cmp_and_jump_insns (index, |
69107307 AO |
3253 | convert_modes |
3254 | (mode, imode, | |
3255 | expand_expr (node->high, NULL_RTX, | |
3256 | VOIDmode, 0), | |
3257 | unsignedp), | |
d43e0b7d | 3258 | GT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3259 | default_label); |
28d81abb RK |
3260 | } |
3261 | ||
923cbdc3 | 3262 | else if (!low_bound && high_bound) |
28d81abb | 3263 | { |
4381f7c2 | 3264 | emit_cmp_and_jump_insns (index, |
69107307 AO |
3265 | convert_modes |
3266 | (mode, imode, | |
3267 | expand_expr (node->low, NULL_RTX, | |
3268 | VOIDmode, 0), | |
3269 | unsignedp), | |
d43e0b7d | 3270 | LT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3271 | default_label); |
28d81abb | 3272 | } |
923cbdc3 JH |
3273 | else if (!low_bound && !high_bound) |
3274 | { | |
9312aecc | 3275 | /* Widen LOW and HIGH to the same width as INDEX. */ |
ae2bcd98 | 3276 | tree type = lang_hooks.types.type_for_mode (mode, unsignedp); |
9312aecc JDA |
3277 | tree low = build1 (CONVERT_EXPR, type, node->low); |
3278 | tree high = build1 (CONVERT_EXPR, type, node->high); | |
ef89d648 | 3279 | rtx low_rtx, new_index, new_bound; |
9312aecc JDA |
3280 | |
3281 | /* Instead of doing two branches, emit one unsigned branch for | |
3282 | (index-low) > (high-low). */ | |
ef89d648 ZW |
3283 | low_rtx = expand_expr (low, NULL_RTX, mode, 0); |
3284 | new_index = expand_simple_binop (mode, MINUS, index, low_rtx, | |
3285 | NULL_RTX, unsignedp, | |
3286 | OPTAB_WIDEN); | |
3244e67d RS |
3287 | new_bound = expand_expr (fold (build2 (MINUS_EXPR, type, |
3288 | high, low)), | |
9312aecc | 3289 | NULL_RTX, mode, 0); |
786de7eb | 3290 | |
9312aecc | 3291 | emit_cmp_and_jump_insns (new_index, new_bound, GT, NULL_RTX, |
d43e0b7d | 3292 | mode, 1, default_label); |
923cbdc3 | 3293 | } |
28d81abb RK |
3294 | |
3295 | emit_jump (label_rtx (node->code_label)); | |
3296 | } | |
3297 | } | |
3298 | } |