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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, |
bff4b63d | 3 | 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 |
c8d3e15a | 4 | Free Software Foundation, Inc. |
28d81abb | 5 | |
1322177d | 6 | This file is part of GCC. |
28d81abb | 7 | |
1322177d LB |
8 | GCC is free software; you can redistribute it and/or modify it under |
9 | the terms of the GNU General Public License as published by the Free | |
9dcd6f09 | 10 | Software Foundation; either version 3, or (at your option) any later |
1322177d | 11 | version. |
28d81abb | 12 | |
1322177d LB |
13 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
14 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
16 | for more details. | |
28d81abb RK |
17 | |
18 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
19 | along with GCC; see the file COPYING3. If not see |
20 | <http://www.gnu.org/licenses/>. */ | |
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 | 32 | #include "rtl.h" |
61158923 | 33 | #include "hard-reg-set.h" |
28d81abb | 34 | #include "tree.h" |
6baf1cc8 | 35 | #include "tm_p.h" |
28d81abb | 36 | #include "flags.h" |
6adb4e3a | 37 | #include "except.h" |
28d81abb | 38 | #include "function.h" |
28d81abb | 39 | #include "insn-config.h" |
28d81abb | 40 | #include "expr.h" |
e78d8e51 | 41 | #include "libfuncs.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 *); |
91b4415a | 107 | static bool tree_conflicts_with_clobbers_p (tree, 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 | 114 | static int estimate_case_costs (case_node_ptr); |
46c5ad27 AJ |
115 | static bool lshift_cheap_p (void); |
116 | static int case_bit_test_cmp (const void *, const void *); | |
117 | static void emit_case_bit_tests (tree, tree, tree, tree, case_node_ptr, rtx); | |
46c5ad27 AJ |
118 | static void balance_case_nodes (case_node_ptr *, case_node_ptr); |
119 | static int node_has_low_bound (case_node_ptr, tree); | |
120 | static int node_has_high_bound (case_node_ptr, tree); | |
121 | static int node_is_bounded (case_node_ptr, tree); | |
46c5ad27 | 122 | static void emit_case_nodes (rtx, case_node_ptr, rtx, tree); |
eb172681 RS |
123 | static struct case_node *add_case_node (struct case_node *, tree, |
124 | tree, tree, tree); | |
0cea056b | 125 | |
28d81abb RK |
126 | \f |
127 | /* Return the rtx-label that corresponds to a LABEL_DECL, | |
128 | creating it if necessary. */ | |
129 | ||
130 | rtx | |
46c5ad27 | 131 | label_rtx (tree label) |
28d81abb | 132 | { |
41374e13 | 133 | gcc_assert (TREE_CODE (label) == LABEL_DECL); |
28d81abb | 134 | |
19e7881c | 135 | if (!DECL_RTL_SET_P (label)) |
6de9cd9a DN |
136 | { |
137 | rtx r = gen_label_rtx (); | |
138 | SET_DECL_RTL (label, r); | |
139 | if (FORCED_LABEL (label) || DECL_NONLOCAL (label)) | |
140 | LABEL_PRESERVE_P (r) = 1; | |
141 | } | |
28d81abb | 142 | |
19e7881c | 143 | return DECL_RTL (label); |
28d81abb RK |
144 | } |
145 | ||
046e4e36 ZW |
146 | /* As above, but also put it on the forced-reference list of the |
147 | function that contains it. */ | |
148 | rtx | |
46c5ad27 | 149 | force_label_rtx (tree label) |
046e4e36 ZW |
150 | { |
151 | rtx ref = label_rtx (label); | |
152 | tree function = decl_function_context (label); | |
153 | struct function *p; | |
154 | ||
41374e13 | 155 | gcc_assert (function); |
046e4e36 | 156 | |
6de9cd9a | 157 | if (function != current_function_decl) |
046e4e36 ZW |
158 | p = find_function_data (function); |
159 | else | |
160 | p = cfun; | |
161 | ||
162 | p->expr->x_forced_labels = gen_rtx_EXPR_LIST (VOIDmode, ref, | |
163 | p->expr->x_forced_labels); | |
164 | return ref; | |
165 | } | |
19e7881c | 166 | |
28d81abb RK |
167 | /* Add an unconditional jump to LABEL as the next sequential instruction. */ |
168 | ||
169 | void | |
46c5ad27 | 170 | emit_jump (rtx label) |
28d81abb RK |
171 | { |
172 | do_pending_stack_adjust (); | |
173 | emit_jump_insn (gen_jump (label)); | |
174 | emit_barrier (); | |
175 | } | |
176 | ||
177 | /* Emit code to jump to the address | |
178 | specified by the pointer expression EXP. */ | |
179 | ||
180 | void | |
46c5ad27 | 181 | expand_computed_goto (tree exp) |
28d81abb | 182 | { |
84217346 | 183 | rtx x = expand_normal (exp); |
ed9a9db1 | 184 | |
5ae6cd0d | 185 | x = convert_memory_address (Pmode, x); |
ffa1a1ce | 186 | |
eb4e1c01 JH |
187 | do_pending_stack_adjust (); |
188 | emit_indirect_jump (x); | |
28d81abb RK |
189 | } |
190 | \f | |
191 | /* Handle goto statements and the labels that they can go to. */ | |
192 | ||
193 | /* Specify the location in the RTL code of a label LABEL, | |
194 | which is a LABEL_DECL tree node. | |
195 | ||
196 | This is used for the kind of label that the user can jump to with a | |
197 | goto statement, and for alternatives of a switch or case statement. | |
198 | RTL labels generated for loops and conditionals don't go through here; | |
199 | they are generated directly at the RTL level, by other functions below. | |
200 | ||
201 | Note that this has nothing to do with defining label *names*. | |
202 | Languages vary in how they do that and what that even means. */ | |
203 | ||
204 | void | |
46c5ad27 | 205 | expand_label (tree label) |
28d81abb | 206 | { |
6de9cd9a | 207 | rtx label_r = label_rtx (label); |
28d81abb RK |
208 | |
209 | do_pending_stack_adjust (); | |
6de9cd9a | 210 | emit_label (label_r); |
28d81abb RK |
211 | if (DECL_NAME (label)) |
212 | LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label)); | |
213 | ||
6de9cd9a DN |
214 | if (DECL_NONLOCAL (label)) |
215 | { | |
216 | expand_nl_goto_receiver (); | |
217 | nonlocal_goto_handler_labels | |
218 | = gen_rtx_EXPR_LIST (VOIDmode, label_r, | |
219 | nonlocal_goto_handler_labels); | |
220 | } | |
221 | ||
222 | if (FORCED_LABEL (label)) | |
223 | forced_labels = gen_rtx_EXPR_LIST (VOIDmode, label_r, forced_labels); | |
caf93cb0 | 224 | |
6de9cd9a DN |
225 | if (DECL_NONLOCAL (label) || FORCED_LABEL (label)) |
226 | maybe_set_first_label_num (label_r); | |
28d81abb RK |
227 | } |
228 | ||
28d81abb RK |
229 | /* Generate RTL code for a `goto' statement with target label LABEL. |
230 | LABEL should be a LABEL_DECL tree node that was or will later be | |
231 | defined with `expand_label'. */ | |
232 | ||
233 | void | |
46c5ad27 | 234 | expand_goto (tree label) |
28d81abb | 235 | { |
6de9cd9a DN |
236 | #ifdef ENABLE_CHECKING |
237 | /* Check for a nonlocal goto to a containing function. Should have | |
238 | gotten translated to __builtin_nonlocal_goto. */ | |
239 | tree context = decl_function_context (label); | |
41374e13 | 240 | gcc_assert (!context || context == current_function_decl); |
28d81abb | 241 | #endif |
4b01bd16 | 242 | |
ac45df5d | 243 | emit_jump (label_rtx (label)); |
28d81abb | 244 | } |
2a230e9d BS |
245 | \f |
246 | /* Return the number of times character C occurs in string S. */ | |
247 | static int | |
46c5ad27 | 248 | n_occurrences (int c, const char *s) |
2a230e9d BS |
249 | { |
250 | int n = 0; | |
251 | while (*s) | |
252 | n += (*s++ == c); | |
253 | return n; | |
254 | } | |
28d81abb RK |
255 | \f |
256 | /* Generate RTL for an asm statement (explicit assembler code). | |
4c46ea23 EB |
257 | STRING is a STRING_CST node containing the assembler code text, |
258 | or an ADDR_EXPR containing a STRING_CST. VOL nonzero means the | |
259 | insn is volatile; don't optimize it. */ | |
28d81abb | 260 | |
bac6bfc5 | 261 | static void |
bff4b63d | 262 | expand_asm_loc (tree string, int vol, location_t locus) |
28d81abb | 263 | { |
4c46ea23 EB |
264 | rtx body; |
265 | ||
266 | if (TREE_CODE (string) == ADDR_EXPR) | |
267 | string = TREE_OPERAND (string, 0); | |
268 | ||
bff4b63d AO |
269 | body = gen_rtx_ASM_INPUT_loc (VOIDmode, |
270 | ggc_strdup (TREE_STRING_POINTER (string)), | |
271 | locus); | |
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 | 324 | /* Canonicalize the output constraint so that it begins with `='. */ |
372d72d9 | 325 | if (p != constraint || *is_inout) |
40b18c0a MM |
326 | { |
327 | char *buf; | |
328 | size_t c_len = strlen (constraint); | |
329 | ||
330 | if (p != constraint) | |
d4ee4d25 | 331 | warning (0, "output constraint %qc for operand %d " |
971801ff | 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 | 554 | if (saw_match && !*allows_reg) |
d4ee4d25 | 555 | warning (0, "matching constraint does not allow a register"); |
f3da0ead | 556 | |
6be2e1f8 RH |
557 | return true; |
558 | } | |
559 | ||
91b4415a R |
560 | /* Return DECL iff there's an overlap between *REGS and DECL, where DECL |
561 | can be an asm-declared register. Called via walk_tree. */ | |
acb5d088 | 562 | |
91b4415a R |
563 | static tree |
564 | decl_overlaps_hard_reg_set_p (tree *declp, int *walk_subtrees ATTRIBUTE_UNUSED, | |
565 | void *data) | |
acb5d088 | 566 | { |
91b4415a R |
567 | tree decl = *declp; |
568 | const HARD_REG_SET *regs = data; | |
569 | ||
3f2de3dc | 570 | if (TREE_CODE (decl) == VAR_DECL) |
acb5d088 | 571 | { |
3f2de3dc | 572 | if (DECL_HARD_REGISTER (decl) |
91b4415a R |
573 | && REG_P (DECL_RTL (decl)) |
574 | && REGNO (DECL_RTL (decl)) < FIRST_PSEUDO_REGISTER) | |
575 | { | |
576 | rtx reg = DECL_RTL (decl); | |
09e18274 RS |
577 | |
578 | if (overlaps_hard_reg_set_p (*regs, GET_MODE (reg), REGNO (reg))) | |
579 | return decl; | |
91b4415a R |
580 | } |
581 | walk_subtrees = 0; | |
61158923 | 582 | } |
3f2de3dc | 583 | else if (TYPE_P (decl) || TREE_CODE (decl) == PARM_DECL) |
91b4415a R |
584 | walk_subtrees = 0; |
585 | return NULL_TREE; | |
61158923 HPN |
586 | } |
587 | ||
91b4415a R |
588 | /* If there is an overlap between *REGS and DECL, return the first overlap |
589 | found. */ | |
590 | tree | |
591 | tree_overlaps_hard_reg_set (tree decl, HARD_REG_SET *regs) | |
592 | { | |
593 | return walk_tree (&decl, decl_overlaps_hard_reg_set_p, regs, NULL); | |
594 | } | |
61158923 HPN |
595 | |
596 | /* Check for overlap between registers marked in CLOBBERED_REGS and | |
91b4415a R |
597 | anything inappropriate in T. Emit error and return the register |
598 | variable definition for error, NULL_TREE for ok. */ | |
61158923 HPN |
599 | |
600 | static bool | |
91b4415a | 601 | tree_conflicts_with_clobbers_p (tree t, HARD_REG_SET *clobbered_regs) |
61158923 HPN |
602 | { |
603 | /* Conflicts between asm-declared register variables and the clobber | |
604 | list are not allowed. */ | |
91b4415a R |
605 | tree overlap = tree_overlaps_hard_reg_set (t, clobbered_regs); |
606 | ||
607 | if (overlap) | |
61158923 HPN |
608 | { |
609 | error ("asm-specifier for variable %qs conflicts with asm clobber list", | |
91b4415a | 610 | IDENTIFIER_POINTER (DECL_NAME (overlap))); |
61158923 HPN |
611 | |
612 | /* Reset registerness to stop multiple errors emitted for a single | |
613 | variable. */ | |
91b4415a | 614 | DECL_REGISTER (overlap) = 0; |
61158923 | 615 | return true; |
acb5d088 | 616 | } |
61158923 | 617 | |
acb5d088 HPN |
618 | return false; |
619 | } | |
620 | ||
28d81abb RK |
621 | /* Generate RTL for an asm statement with arguments. |
622 | STRING is the instruction template. | |
623 | OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs. | |
624 | Each output or input has an expression in the TREE_VALUE and | |
2ec37136 | 625 | and a tree list in TREE_PURPOSE which in turn contains a constraint |
786de7eb | 626 | name in TREE_VALUE (or NULL_TREE) and a constraint string |
2ec37136 | 627 | in TREE_PURPOSE. |
28d81abb RK |
628 | CLOBBERS is a list of STRING_CST nodes each naming a hard register |
629 | that is clobbered by this insn. | |
630 | ||
631 | Not all kinds of lvalue that may appear in OUTPUTS can be stored directly. | |
632 | Some elements of OUTPUTS may be replaced with trees representing temporary | |
633 | values. The caller should copy those temporary values to the originally | |
634 | specified lvalues. | |
635 | ||
636 | VOL nonzero means the insn is volatile; don't optimize it. */ | |
637 | ||
bac6bfc5 | 638 | static void |
46c5ad27 | 639 | expand_asm_operands (tree string, tree outputs, tree inputs, |
177560b2 | 640 | tree clobbers, int vol, location_t locus) |
28d81abb | 641 | { |
84b72302 | 642 | rtvec argvec, constraintvec; |
28d81abb RK |
643 | rtx body; |
644 | int ninputs = list_length (inputs); | |
645 | int noutputs = list_length (outputs); | |
6be2e1f8 | 646 | int ninout; |
b4ccaa16 | 647 | int nclobbers; |
acb5d088 HPN |
648 | HARD_REG_SET clobbered_regs; |
649 | int clobber_conflict_found = 0; | |
28d81abb | 650 | tree tail; |
7dc8b126 | 651 | tree t; |
b3694847 | 652 | int i; |
28d81abb | 653 | /* Vector of RTX's of evaluated output operands. */ |
703ad42b KG |
654 | rtx *output_rtx = alloca (noutputs * sizeof (rtx)); |
655 | int *inout_opnum = alloca (noutputs * sizeof (int)); | |
656 | rtx *real_output_rtx = alloca (noutputs * sizeof (rtx)); | |
235c5021 | 657 | enum machine_mode *inout_mode |
703ad42b | 658 | = alloca (noutputs * sizeof (enum machine_mode)); |
84b72302 | 659 | const char **constraints |
703ad42b | 660 | = alloca ((noutputs + ninputs) * sizeof (const char *)); |
1b3d8f8a | 661 | int old_generating_concat_p = generating_concat_p; |
28d81abb | 662 | |
e5e809f4 | 663 | /* An ASM with no outputs needs to be treated as volatile, for now. */ |
296f8acc JL |
664 | if (noutputs == 0) |
665 | vol = 1; | |
666 | ||
84b72302 RH |
667 | if (! check_operand_nalternatives (outputs, inputs)) |
668 | return; | |
669 | ||
7dc8b126 JM |
670 | string = resolve_asm_operand_names (string, outputs, inputs); |
671 | ||
672 | /* Collect constraints. */ | |
673 | i = 0; | |
674 | for (t = outputs; t ; t = TREE_CHAIN (t), i++) | |
675 | constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t))); | |
676 | for (t = inputs; t ; t = TREE_CHAIN (t), i++) | |
677 | constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t))); | |
84b72302 | 678 | |
57bcb97a RH |
679 | /* Sometimes we wish to automatically clobber registers across an asm. |
680 | Case in point is when the i386 backend moved from cc0 to a hard reg -- | |
f63d1bf7 | 681 | maintaining source-level compatibility means automatically clobbering |
57bcb97a | 682 | the flags register. */ |
61158923 | 683 | clobbers = targetm.md_asm_clobbers (outputs, inputs, clobbers); |
57bcb97a | 684 | |
b4ccaa16 RS |
685 | /* Count the number of meaningful clobbered registers, ignoring what |
686 | we would ignore later. */ | |
687 | nclobbers = 0; | |
acb5d088 | 688 | CLEAR_HARD_REG_SET (clobbered_regs); |
b4ccaa16 RS |
689 | for (tail = clobbers; tail; tail = TREE_CHAIN (tail)) |
690 | { | |
123b24e7 VR |
691 | const char *regname; |
692 | ||
693 | if (TREE_VALUE (tail) == error_mark_node) | |
694 | return; | |
695 | regname = TREE_STRING_POINTER (TREE_VALUE (tail)); | |
14a774a9 | 696 | |
c09e6498 RS |
697 | i = decode_reg_name (regname); |
698 | if (i >= 0 || i == -4) | |
b4ccaa16 | 699 | ++nclobbers; |
7859e3ac | 700 | else if (i == -2) |
971801ff | 701 | error ("unknown register name %qs in %<asm%>", regname); |
acb5d088 HPN |
702 | |
703 | /* Mark clobbered registers. */ | |
704 | if (i >= 0) | |
e54b4cae | 705 | { |
ea4b7848 | 706 | /* Clobbering the PIC register is an error. */ |
fc555370 | 707 | if (i == (int) PIC_OFFSET_TABLE_REGNUM) |
e54b4cae | 708 | { |
971801ff | 709 | error ("PIC register %qs clobbered in %<asm%>", regname); |
e54b4cae EB |
710 | return; |
711 | } | |
712 | ||
713 | SET_HARD_REG_BIT (clobbered_regs, i); | |
714 | } | |
b4ccaa16 RS |
715 | } |
716 | ||
6be2e1f8 RH |
717 | /* First pass over inputs and outputs checks validity and sets |
718 | mark_addressable if needed. */ | |
719 | ||
720 | ninout = 0; | |
28d81abb RK |
721 | for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) |
722 | { | |
723 | tree val = TREE_VALUE (tail); | |
b50a024d | 724 | tree type = TREE_TYPE (val); |
6be2e1f8 | 725 | const char *constraint; |
40b18c0a MM |
726 | bool is_inout; |
727 | bool allows_reg; | |
728 | bool allows_mem; | |
28d81abb RK |
729 | |
730 | /* If there's an erroneous arg, emit no insn. */ | |
40b18c0a | 731 | if (type == error_mark_node) |
28d81abb RK |
732 | return; |
733 | ||
40b18c0a MM |
734 | /* Try to parse the output constraint. If that fails, there's |
735 | no point in going further. */ | |
6be2e1f8 RH |
736 | constraint = constraints[i]; |
737 | if (!parse_output_constraint (&constraint, i, ninputs, noutputs, | |
738 | &allows_mem, &allows_reg, &is_inout)) | |
739 | return; | |
740 | ||
741 | if (! allows_reg | |
742 | && (allows_mem | |
743 | || is_inout | |
744 | || (DECL_P (val) | |
f8cfc6aa | 745 | && REG_P (DECL_RTL (val)) |
6be2e1f8 | 746 | && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))) |
ae2bcd98 | 747 | lang_hooks.mark_addressable (val); |
6be2e1f8 RH |
748 | |
749 | if (is_inout) | |
750 | ninout++; | |
751 | } | |
752 | ||
753 | ninputs += ninout; | |
754 | if (ninputs + noutputs > MAX_RECOG_OPERANDS) | |
755 | { | |
971801ff | 756 | error ("more than %d operands in %<asm%>", MAX_RECOG_OPERANDS); |
6be2e1f8 RH |
757 | return; |
758 | } | |
759 | ||
760 | for (i = 0, tail = inputs; tail; i++, tail = TREE_CHAIN (tail)) | |
761 | { | |
762 | bool allows_reg, allows_mem; | |
763 | const char *constraint; | |
764 | ||
765 | /* If there's an erroneous arg, emit no insn, because the ASM_INPUT | |
766 | would get VOIDmode and that could cause a crash in reload. */ | |
767 | if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node) | |
768 | return; | |
769 | ||
770 | constraint = constraints[i + noutputs]; | |
771 | if (! parse_input_constraint (&constraint, i, ninputs, noutputs, ninout, | |
772 | constraints, &allows_mem, &allows_reg)) | |
40b18c0a | 773 | return; |
d09a75ae | 774 | |
6be2e1f8 | 775 | if (! allows_reg && allows_mem) |
ae2bcd98 | 776 | lang_hooks.mark_addressable (TREE_VALUE (tail)); |
6be2e1f8 RH |
777 | } |
778 | ||
779 | /* Second pass evaluates arguments. */ | |
780 | ||
781 | ninout = 0; | |
782 | for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) | |
783 | { | |
784 | tree val = TREE_VALUE (tail); | |
785 | tree type = TREE_TYPE (val); | |
786 | bool is_inout; | |
787 | bool allows_reg; | |
788 | bool allows_mem; | |
5b50aa9d | 789 | rtx op; |
41374e13 | 790 | bool ok; |
6be2e1f8 | 791 | |
41374e13 | 792 | ok = parse_output_constraint (&constraints[i], i, ninputs, |
6be2e1f8 | 793 | noutputs, &allows_mem, &allows_reg, |
41374e13 NS |
794 | &is_inout); |
795 | gcc_assert (ok); | |
6be2e1f8 | 796 | |
d09a75ae RK |
797 | /* If an output operand is not a decl or indirect ref and our constraint |
798 | allows a register, make a temporary to act as an intermediate. | |
799 | Make the asm insn write into that, then our caller will copy it to | |
800 | the real output operand. Likewise for promoted variables. */ | |
28d81abb | 801 | |
1b3d8f8a GK |
802 | generating_concat_p = 0; |
803 | ||
947255ed | 804 | real_output_rtx[i] = NULL_RTX; |
1afbe1c4 RH |
805 | if ((TREE_CODE (val) == INDIRECT_REF |
806 | && allows_mem) | |
2f939d94 | 807 | || (DECL_P (val) |
f8cfc6aa JQ |
808 | && (allows_mem || REG_P (DECL_RTL (val))) |
809 | && ! (REG_P (DECL_RTL (val)) | |
d09a75ae | 810 | && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type))) |
11579f33 | 811 | || ! allows_reg |
2a230e9d | 812 | || is_inout) |
d09a75ae | 813 | { |
5b50aa9d | 814 | op = expand_expr (val, NULL_RTX, VOIDmode, EXPAND_WRITE); |
3c0cb5de | 815 | if (MEM_P (op)) |
5b50aa9d | 816 | op = validize_mem (op); |
d09a75ae | 817 | |
3c0cb5de | 818 | if (! allows_reg && !MEM_P (op)) |
d09a75ae | 819 | error ("output number %d not directly addressable", i); |
3c0cb5de | 820 | if ((! allows_mem && MEM_P (op)) |
5b50aa9d | 821 | || GET_CODE (op) == CONCAT) |
947255ed | 822 | { |
ad76cef8 | 823 | real_output_rtx[i] = op; |
5b50aa9d | 824 | op = gen_reg_rtx (GET_MODE (op)); |
11579f33 | 825 | if (is_inout) |
5b50aa9d | 826 | emit_move_insn (op, real_output_rtx[i]); |
947255ed | 827 | } |
d09a75ae | 828 | } |
b50a024d | 829 | else |
e619bb8d | 830 | { |
5b50aa9d RH |
831 | op = assign_temp (type, 0, 0, 1); |
832 | op = validize_mem (op); | |
833 | TREE_VALUE (tail) = make_tree (type, op); | |
b50a024d | 834 | } |
5b50aa9d | 835 | output_rtx[i] = op; |
235c5021 | 836 | |
1b3d8f8a GK |
837 | generating_concat_p = old_generating_concat_p; |
838 | ||
2a230e9d | 839 | if (is_inout) |
235c5021 | 840 | { |
6be2e1f8 | 841 | inout_mode[ninout] = TYPE_MODE (type); |
235c5021 RK |
842 | inout_opnum[ninout++] = i; |
843 | } | |
acb5d088 | 844 | |
91b4415a | 845 | if (tree_conflicts_with_clobbers_p (val, &clobbered_regs)) |
acb5d088 | 846 | clobber_conflict_found = 1; |
28d81abb RK |
847 | } |
848 | ||
84b72302 RH |
849 | /* Make vectors for the expression-rtx, constraint strings, |
850 | and named operands. */ | |
28d81abb RK |
851 | |
852 | argvec = rtvec_alloc (ninputs); | |
84b72302 | 853 | constraintvec = rtvec_alloc (ninputs); |
28d81abb | 854 | |
6462bb43 AO |
855 | body = gen_rtx_ASM_OPERANDS ((noutputs == 0 ? VOIDmode |
856 | : GET_MODE (output_rtx[0])), | |
a396f8ae | 857 | ggc_strdup (TREE_STRING_POINTER (string)), |
84b72302 | 858 | empty_string, 0, argvec, constraintvec, |
6773e15f | 859 | locus); |
c85f7c16 | 860 | |
78418280 | 861 | MEM_VOLATILE_P (body) = vol; |
28d81abb RK |
862 | |
863 | /* Eval the inputs and put them into ARGVEC. | |
864 | Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */ | |
865 | ||
84b72302 | 866 | for (i = 0, tail = inputs; tail; tail = TREE_CHAIN (tail), ++i) |
28d81abb | 867 | { |
6be2e1f8 RH |
868 | bool allows_reg, allows_mem; |
869 | const char *constraint; | |
870 | tree val, type; | |
1f06ee8d | 871 | rtx op; |
41374e13 | 872 | bool ok; |
28d81abb | 873 | |
6be2e1f8 | 874 | constraint = constraints[i + noutputs]; |
41374e13 NS |
875 | ok = parse_input_constraint (&constraint, i, ninputs, noutputs, ninout, |
876 | constraints, &allows_mem, &allows_reg); | |
877 | gcc_assert (ok); | |
2a230e9d | 878 | |
6be2e1f8 | 879 | generating_concat_p = 0; |
65fed0cb | 880 | |
6be2e1f8 RH |
881 | val = TREE_VALUE (tail); |
882 | type = TREE_TYPE (val); | |
6d40c489 RS |
883 | /* EXPAND_INITIALIZER will not generate code for valid initializer |
884 | constants, but will still generate code for other types of operand. | |
885 | This is the behavior we want for constant constraints. */ | |
017e1b43 | 886 | op = expand_expr (val, NULL_RTX, VOIDmode, |
6d40c489 RS |
887 | allows_reg ? EXPAND_NORMAL |
888 | : allows_mem ? EXPAND_MEMORY | |
889 | : EXPAND_INITIALIZER); | |
65fed0cb | 890 | |
1b3d8f8a | 891 | /* Never pass a CONCAT to an ASM. */ |
1b3d8f8a GK |
892 | if (GET_CODE (op) == CONCAT) |
893 | op = force_reg (GET_MODE (op), op); | |
3c0cb5de | 894 | else if (MEM_P (op)) |
5b50aa9d | 895 | op = validize_mem (op); |
1b3d8f8a | 896 | |
1afbe1c4 | 897 | if (asm_operand_ok (op, constraint) <= 0) |
65fed0cb | 898 | { |
4bbcb8fc | 899 | if (allows_reg && TYPE_MODE (type) != BLKmode) |
6be2e1f8 | 900 | op = force_reg (TYPE_MODE (type), op); |
11579f33 | 901 | else if (!allows_mem) |
d4ee4d25 | 902 | warning (0, "asm operand %d probably doesn%'t match constraints", |
84b72302 | 903 | i + noutputs); |
3c0cb5de | 904 | else if (MEM_P (op)) |
6be2e1f8 | 905 | { |
d50ad6af RH |
906 | /* We won't recognize either volatile memory or memory |
907 | with a queued address as available a memory_operand | |
908 | at this point. Ignore it: clearly this *is* a memory. */ | |
6be2e1f8 | 909 | } |
1f06ee8d | 910 | else |
017e1b43 | 911 | { |
d4ee4d25 | 912 | warning (0, "use of memory input without lvalue in " |
71ed1fdb | 913 | "asm operand %d is deprecated", i + noutputs); |
017e1b43 RH |
914 | |
915 | if (CONSTANT_P (op)) | |
916 | { | |
9c858681 RS |
917 | rtx mem = force_const_mem (TYPE_MODE (type), op); |
918 | if (mem) | |
919 | op = validize_mem (mem); | |
920 | else | |
921 | op = force_reg (TYPE_MODE (type), op); | |
017e1b43 | 922 | } |
f8cfc6aa | 923 | if (REG_P (op) |
9c858681 | 924 | || GET_CODE (op) == SUBREG |
9c858681 | 925 | || GET_CODE (op) == CONCAT) |
017e1b43 RH |
926 | { |
927 | tree qual_type = build_qualified_type (type, | |
928 | (TYPE_QUALS (type) | |
929 | | TYPE_QUAL_CONST)); | |
930 | rtx memloc = assign_temp (qual_type, 1, 1, 1); | |
931 | memloc = validize_mem (memloc); | |
932 | emit_move_insn (memloc, op); | |
933 | op = memloc; | |
934 | } | |
935 | } | |
65fed0cb | 936 | } |
6be2e1f8 | 937 | |
1b3d8f8a | 938 | generating_concat_p = old_generating_concat_p; |
6462bb43 | 939 | ASM_OPERANDS_INPUT (body, i) = op; |
2a230e9d | 940 | |
6462bb43 | 941 | ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, i) |
a396f8ae GK |
942 | = gen_rtx_ASM_INPUT (TYPE_MODE (type), |
943 | ggc_strdup (constraints[i + noutputs])); | |
acb5d088 | 944 | |
91b4415a | 945 | if (tree_conflicts_with_clobbers_p (val, &clobbered_regs)) |
acb5d088 | 946 | clobber_conflict_found = 1; |
28d81abb RK |
947 | } |
948 | ||
14a774a9 RK |
949 | /* Protect all the operands from the queue now that they have all been |
950 | evaluated. */ | |
28d81abb | 951 | |
1b3d8f8a GK |
952 | generating_concat_p = 0; |
953 | ||
4381f7c2 | 954 | /* For in-out operands, copy output rtx to input rtx. */ |
235c5021 RK |
955 | for (i = 0; i < ninout; i++) |
956 | { | |
235c5021 | 957 | int j = inout_opnum[i]; |
84b72302 | 958 | char buffer[16]; |
235c5021 | 959 | |
6462bb43 | 960 | ASM_OPERANDS_INPUT (body, ninputs - ninout + i) |
235c5021 | 961 | = output_rtx[j]; |
84b72302 RH |
962 | |
963 | sprintf (buffer, "%d", j); | |
6462bb43 | 964 | ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, ninputs - ninout + i) |
485bad26 | 965 | = gen_rtx_ASM_INPUT (inout_mode[i], ggc_strdup (buffer)); |
235c5021 RK |
966 | } |
967 | ||
1b3d8f8a GK |
968 | generating_concat_p = old_generating_concat_p; |
969 | ||
28d81abb | 970 | /* Now, for each output, construct an rtx |
84b72302 RH |
971 | (set OUTPUT (asm_operands INSN OUTPUTCONSTRAINT OUTPUTNUMBER |
972 | ARGVEC CONSTRAINTS OPNAMES)) | |
28d81abb RK |
973 | If there is more than one, put them inside a PARALLEL. */ |
974 | ||
975 | if (noutputs == 1 && nclobbers == 0) | |
976 | { | |
a396f8ae | 977 | ASM_OPERANDS_OUTPUT_CONSTRAINT (body) = ggc_strdup (constraints[0]); |
4977bab6 | 978 | emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body)); |
28d81abb | 979 | } |
14a774a9 | 980 | |
28d81abb RK |
981 | else if (noutputs == 0 && nclobbers == 0) |
982 | { | |
983 | /* No output operands: put in a raw ASM_OPERANDS rtx. */ | |
4977bab6 | 984 | emit_insn (body); |
28d81abb | 985 | } |
14a774a9 | 986 | |
28d81abb RK |
987 | else |
988 | { | |
989 | rtx obody = body; | |
990 | int num = noutputs; | |
14a774a9 RK |
991 | |
992 | if (num == 0) | |
993 | num = 1; | |
994 | ||
38a448ca | 995 | body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers)); |
28d81abb RK |
996 | |
997 | /* For each output operand, store a SET. */ | |
28d81abb RK |
998 | for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) |
999 | { | |
1000 | XVECEXP (body, 0, i) | |
38a448ca RH |
1001 | = gen_rtx_SET (VOIDmode, |
1002 | output_rtx[i], | |
c5c76735 | 1003 | gen_rtx_ASM_OPERANDS |
6462bb43 | 1004 | (GET_MODE (output_rtx[i]), |
a396f8ae GK |
1005 | ggc_strdup (TREE_STRING_POINTER (string)), |
1006 | ggc_strdup (constraints[i]), | |
1007 | i, argvec, constraintvec, locus)); | |
c5c76735 | 1008 | |
28d81abb RK |
1009 | MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol; |
1010 | } | |
1011 | ||
1012 | /* If there are no outputs (but there are some clobbers) | |
1013 | store the bare ASM_OPERANDS into the PARALLEL. */ | |
1014 | ||
1015 | if (i == 0) | |
1016 | XVECEXP (body, 0, i++) = obody; | |
1017 | ||
1018 | /* Store (clobber REG) for each clobbered register specified. */ | |
1019 | ||
b4ccaa16 | 1020 | for (tail = clobbers; tail; tail = TREE_CHAIN (tail)) |
28d81abb | 1021 | { |
47ee9bcb | 1022 | const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail)); |
b4ac57ab | 1023 | int j = decode_reg_name (regname); |
acb5d088 | 1024 | rtx clobbered_reg; |
28d81abb | 1025 | |
b4ac57ab | 1026 | if (j < 0) |
28d81abb | 1027 | { |
c09e6498 | 1028 | if (j == -3) /* `cc', which is not a register */ |
dcfedcd0 RK |
1029 | continue; |
1030 | ||
c09e6498 RS |
1031 | if (j == -4) /* `memory', don't cache memory across asm */ |
1032 | { | |
bffc6177 | 1033 | XVECEXP (body, 0, i++) |
38a448ca | 1034 | = gen_rtx_CLOBBER (VOIDmode, |
c5c76735 JL |
1035 | gen_rtx_MEM |
1036 | (BLKmode, | |
1037 | gen_rtx_SCRATCH (VOIDmode))); | |
c09e6498 RS |
1038 | continue; |
1039 | } | |
1040 | ||
956d6950 | 1041 | /* Ignore unknown register, error already signaled. */ |
cc1f5387 | 1042 | continue; |
28d81abb RK |
1043 | } |
1044 | ||
1045 | /* Use QImode since that's guaranteed to clobber just one reg. */ | |
acb5d088 HPN |
1046 | clobbered_reg = gen_rtx_REG (QImode, j); |
1047 | ||
1048 | /* Do sanity check for overlap between clobbers and respectively | |
1049 | input and outputs that hasn't been handled. Such overlap | |
1050 | should have been detected and reported above. */ | |
1051 | if (!clobber_conflict_found) | |
1052 | { | |
1053 | int opno; | |
1054 | ||
1055 | /* We test the old body (obody) contents to avoid tripping | |
1056 | over the under-construction body. */ | |
1057 | for (opno = 0; opno < noutputs; opno++) | |
1058 | if (reg_overlap_mentioned_p (clobbered_reg, output_rtx[opno])) | |
1059 | internal_error ("asm clobber conflict with output operand"); | |
1060 | ||
1061 | for (opno = 0; opno < ninputs - ninout; opno++) | |
1062 | if (reg_overlap_mentioned_p (clobbered_reg, | |
1063 | ASM_OPERANDS_INPUT (obody, opno))) | |
1064 | internal_error ("asm clobber conflict with input operand"); | |
1065 | } | |
1066 | ||
b4ccaa16 | 1067 | XVECEXP (body, 0, i++) |
acb5d088 | 1068 | = gen_rtx_CLOBBER (VOIDmode, clobbered_reg); |
28d81abb RK |
1069 | } |
1070 | ||
4977bab6 | 1071 | emit_insn (body); |
28d81abb RK |
1072 | } |
1073 | ||
947255ed RH |
1074 | /* For any outputs that needed reloading into registers, spill them |
1075 | back to where they belong. */ | |
1076 | for (i = 0; i < noutputs; ++i) | |
1077 | if (real_output_rtx[i]) | |
1078 | emit_move_insn (real_output_rtx[i], output_rtx[i]); | |
1079 | ||
d8d72314 | 1080 | cfun->has_asm_statement = 1; |
28d81abb RK |
1081 | free_temp_slots (); |
1082 | } | |
84b72302 | 1083 | |
6de9cd9a DN |
1084 | void |
1085 | expand_asm_expr (tree exp) | |
1086 | { | |
1087 | int noutputs, i; | |
1088 | tree outputs, tail; | |
1089 | tree *o; | |
1090 | ||
1091 | if (ASM_INPUT_P (exp)) | |
1092 | { | |
bff4b63d | 1093 | expand_asm_loc (ASM_STRING (exp), ASM_VOLATILE_P (exp), input_location); |
6de9cd9a DN |
1094 | return; |
1095 | } | |
1096 | ||
1097 | outputs = ASM_OUTPUTS (exp); | |
1098 | noutputs = list_length (outputs); | |
1099 | /* o[I] is the place that output number I should be written. */ | |
1100 | o = (tree *) alloca (noutputs * sizeof (tree)); | |
1101 | ||
1102 | /* Record the contents of OUTPUTS before it is modified. */ | |
1103 | for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) | |
1104 | o[i] = TREE_VALUE (tail); | |
1105 | ||
1106 | /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of | |
1107 | OUTPUTS some trees for where the values were actually stored. */ | |
1108 | expand_asm_operands (ASM_STRING (exp), outputs, ASM_INPUTS (exp), | |
1109 | ASM_CLOBBERS (exp), ASM_VOLATILE_P (exp), | |
1110 | input_location); | |
1111 | ||
1112 | /* Copy all the intermediate outputs into the specified outputs. */ | |
1113 | for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) | |
1114 | { | |
1115 | if (o[i] != TREE_VALUE (tail)) | |
1116 | { | |
79f5e442 | 1117 | expand_assignment (o[i], TREE_VALUE (tail), false); |
6de9cd9a DN |
1118 | free_temp_slots (); |
1119 | ||
1120 | /* Restore the original value so that it's correct the next | |
1121 | time we expand this function. */ | |
1122 | TREE_VALUE (tail) = o[i]; | |
1123 | } | |
1124 | } | |
6de9cd9a DN |
1125 | } |
1126 | ||
84b72302 RH |
1127 | /* A subroutine of expand_asm_operands. Check that all operands have |
1128 | the same number of alternatives. Return true if so. */ | |
1129 | ||
1130 | static bool | |
46c5ad27 | 1131 | check_operand_nalternatives (tree outputs, tree inputs) |
84b72302 RH |
1132 | { |
1133 | if (outputs || inputs) | |
1134 | { | |
1135 | tree tmp = TREE_PURPOSE (outputs ? outputs : inputs); | |
1136 | int nalternatives | |
1137 | = n_occurrences (',', TREE_STRING_POINTER (TREE_VALUE (tmp))); | |
1138 | tree next = inputs; | |
1139 | ||
1140 | if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES) | |
1141 | { | |
971801ff | 1142 | error ("too many alternatives in %<asm%>"); |
84b72302 RH |
1143 | return false; |
1144 | } | |
1145 | ||
1146 | tmp = outputs; | |
1147 | while (tmp) | |
1148 | { | |
1149 | const char *constraint | |
1150 | = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tmp))); | |
1151 | ||
1152 | if (n_occurrences (',', constraint) != nalternatives) | |
1153 | { | |
971801ff JM |
1154 | error ("operand constraints for %<asm%> differ " |
1155 | "in number of alternatives"); | |
84b72302 RH |
1156 | return false; |
1157 | } | |
1158 | ||
1159 | if (TREE_CHAIN (tmp)) | |
1160 | tmp = TREE_CHAIN (tmp); | |
1161 | else | |
1162 | tmp = next, next = 0; | |
1163 | } | |
1164 | } | |
1165 | ||
1166 | return true; | |
1167 | } | |
1168 | ||
1169 | /* A subroutine of expand_asm_operands. Check that all operand names | |
1170 | are unique. Return true if so. We rely on the fact that these names | |
1171 | are identifiers, and so have been canonicalized by get_identifier, | |
1172 | so all we need are pointer comparisons. */ | |
1173 | ||
1174 | static bool | |
46c5ad27 | 1175 | check_unique_operand_names (tree outputs, tree inputs) |
84b72302 RH |
1176 | { |
1177 | tree i, j; | |
1178 | ||
1179 | for (i = outputs; i ; i = TREE_CHAIN (i)) | |
1180 | { | |
1181 | tree i_name = TREE_PURPOSE (TREE_PURPOSE (i)); | |
1182 | if (! i_name) | |
1183 | continue; | |
1184 | ||
1185 | for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j)) | |
fc552851 | 1186 | if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j)))) |
84b72302 RH |
1187 | goto failure; |
1188 | } | |
1189 | ||
1190 | for (i = inputs; i ; i = TREE_CHAIN (i)) | |
1191 | { | |
1192 | tree i_name = TREE_PURPOSE (TREE_PURPOSE (i)); | |
1193 | if (! i_name) | |
1194 | continue; | |
1195 | ||
1196 | for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j)) | |
fc552851 | 1197 | if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j)))) |
84b72302 RH |
1198 | goto failure; |
1199 | for (j = outputs; j ; j = TREE_CHAIN (j)) | |
fc552851 | 1200 | if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j)))) |
84b72302 RH |
1201 | goto failure; |
1202 | } | |
1203 | ||
1204 | return true; | |
1205 | ||
1206 | failure: | |
971801ff | 1207 | error ("duplicate asm operand name %qs", |
fc552851 | 1208 | TREE_STRING_POINTER (TREE_PURPOSE (TREE_PURPOSE (i)))); |
84b72302 RH |
1209 | return false; |
1210 | } | |
1211 | ||
1212 | /* A subroutine of expand_asm_operands. Resolve the names of the operands | |
1213 | in *POUTPUTS and *PINPUTS to numbers, and replace the name expansions in | |
1214 | STRING and in the constraints to those numbers. */ | |
1215 | ||
7dc8b126 JM |
1216 | tree |
1217 | resolve_asm_operand_names (tree string, tree outputs, tree inputs) | |
84b72302 | 1218 | { |
7dc8b126 | 1219 | char *buffer; |
84b72302 | 1220 | char *p; |
40209195 | 1221 | const char *c; |
84b72302 RH |
1222 | tree t; |
1223 | ||
1456deaf JM |
1224 | check_unique_operand_names (outputs, inputs); |
1225 | ||
7dc8b126 JM |
1226 | /* Substitute [<name>] in input constraint strings. There should be no |
1227 | named operands in output constraints. */ | |
1228 | for (t = inputs; t ; t = TREE_CHAIN (t)) | |
1229 | { | |
40209195 | 1230 | c = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t))); |
7dc8b126 JM |
1231 | if (strchr (c, '[') != NULL) |
1232 | { | |
1233 | p = buffer = xstrdup (c); | |
1234 | while ((p = strchr (p, '[')) != NULL) | |
1235 | p = resolve_operand_name_1 (p, outputs, inputs); | |
1236 | TREE_VALUE (TREE_PURPOSE (t)) | |
1237 | = build_string (strlen (buffer), buffer); | |
1238 | free (buffer); | |
1239 | } | |
1240 | } | |
1241 | ||
40209195 JM |
1242 | /* Now check for any needed substitutions in the template. */ |
1243 | c = TREE_STRING_POINTER (string); | |
1244 | while ((c = strchr (c, '%')) != NULL) | |
84b72302 | 1245 | { |
40209195 JM |
1246 | if (c[1] == '[') |
1247 | break; | |
1248 | else if (ISALPHA (c[1]) && c[2] == '[') | |
1249 | break; | |
7abcb63a RH |
1250 | else |
1251 | { | |
40209195 | 1252 | c += 1; |
7abcb63a RH |
1253 | continue; |
1254 | } | |
84b72302 RH |
1255 | } |
1256 | ||
40209195 JM |
1257 | if (c) |
1258 | { | |
1259 | /* OK, we need to make a copy so we can perform the substitutions. | |
1260 | Assume that we will not need extra space--we get to remove '[' | |
1261 | and ']', which means we cannot have a problem until we have more | |
1262 | than 999 operands. */ | |
1263 | buffer = xstrdup (TREE_STRING_POINTER (string)); | |
1264 | p = buffer + (c - TREE_STRING_POINTER (string)); | |
caf93cb0 | 1265 | |
40209195 JM |
1266 | while ((p = strchr (p, '%')) != NULL) |
1267 | { | |
1268 | if (p[1] == '[') | |
1269 | p += 1; | |
1270 | else if (ISALPHA (p[1]) && p[2] == '[') | |
1271 | p += 2; | |
1272 | else | |
1273 | { | |
1274 | p += 1; | |
1275 | continue; | |
1276 | } | |
1277 | ||
1278 | p = resolve_operand_name_1 (p, outputs, inputs); | |
1279 | } | |
1280 | ||
1281 | string = build_string (strlen (buffer), buffer); | |
1282 | free (buffer); | |
1283 | } | |
84b72302 | 1284 | |
84b72302 RH |
1285 | return string; |
1286 | } | |
1287 | ||
1288 | /* A subroutine of resolve_operand_names. P points to the '[' for a | |
1289 | potential named operand of the form [<name>]. In place, replace | |
786de7eb | 1290 | the name and brackets with a number. Return a pointer to the |
84b72302 RH |
1291 | balance of the string after substitution. */ |
1292 | ||
1293 | static char * | |
46c5ad27 | 1294 | resolve_operand_name_1 (char *p, tree outputs, tree inputs) |
84b72302 RH |
1295 | { |
1296 | char *q; | |
1297 | int op; | |
1298 | tree t; | |
1299 | size_t len; | |
1300 | ||
1301 | /* Collect the operand name. */ | |
1302 | q = strchr (p, ']'); | |
1303 | if (!q) | |
1304 | { | |
1305 | error ("missing close brace for named operand"); | |
1306 | return strchr (p, '\0'); | |
1307 | } | |
1308 | len = q - p - 1; | |
1309 | ||
1310 | /* Resolve the name to a number. */ | |
1311 | for (op = 0, t = outputs; t ; t = TREE_CHAIN (t), op++) | |
1312 | { | |
fc552851 RS |
1313 | tree name = TREE_PURPOSE (TREE_PURPOSE (t)); |
1314 | if (name) | |
edd1967d | 1315 | { |
fc552851 | 1316 | const char *c = TREE_STRING_POINTER (name); |
edd1967d RH |
1317 | if (strncmp (c, p + 1, len) == 0 && c[len] == '\0') |
1318 | goto found; | |
1319 | } | |
84b72302 RH |
1320 | } |
1321 | for (t = inputs; t ; t = TREE_CHAIN (t), op++) | |
1322 | { | |
fc552851 RS |
1323 | tree name = TREE_PURPOSE (TREE_PURPOSE (t)); |
1324 | if (name) | |
edd1967d | 1325 | { |
fc552851 | 1326 | const char *c = TREE_STRING_POINTER (name); |
edd1967d RH |
1327 | if (strncmp (c, p + 1, len) == 0 && c[len] == '\0') |
1328 | goto found; | |
1329 | } | |
84b72302 RH |
1330 | } |
1331 | ||
1332 | *q = '\0'; | |
971801ff | 1333 | error ("undefined named operand %qs", p + 1); |
84b72302 RH |
1334 | op = 0; |
1335 | found: | |
1336 | ||
1337 | /* Replace the name with the number. Unfortunately, not all libraries | |
1338 | get the return value of sprintf correct, so search for the end of the | |
1339 | generated string by hand. */ | |
1340 | sprintf (p, "%d", op); | |
1341 | p = strchr (p, '\0'); | |
1342 | ||
1343 | /* Verify the no extra buffer space assumption. */ | |
41374e13 | 1344 | gcc_assert (p <= q); |
84b72302 RH |
1345 | |
1346 | /* Shift the rest of the buffer down to fill the gap. */ | |
1347 | memmove (p, q + 1, strlen (q + 1) + 1); | |
1348 | ||
1349 | return p; | |
1350 | } | |
28d81abb | 1351 | \f |
4dfa0342 | 1352 | /* Generate RTL to evaluate the expression EXP. */ |
28d81abb RK |
1353 | |
1354 | void | |
46c5ad27 | 1355 | expand_expr_stmt (tree exp) |
1574ef13 AO |
1356 | { |
1357 | rtx value; | |
1358 | tree type; | |
b6ec8c5f | 1359 | |
49452c07 | 1360 | value = expand_expr (exp, const0_rtx, VOIDmode, EXPAND_NORMAL); |
07beea0d AH |
1361 | if (GIMPLE_TUPLE_P (exp)) |
1362 | type = void_type_node; | |
1363 | else | |
1574ef13 | 1364 | type = TREE_TYPE (exp); |
28d81abb RK |
1365 | |
1366 | /* If all we do is reference a volatile value in memory, | |
1367 | copy it to a register to be sure it is actually touched. */ | |
3c0cb5de | 1368 | if (value && MEM_P (value) && TREE_THIS_VOLATILE (exp)) |
28d81abb | 1369 | { |
1574ef13 | 1370 | if (TYPE_MODE (type) == VOIDmode) |
6a5bbbe6 | 1371 | ; |
1574ef13 AO |
1372 | else if (TYPE_MODE (type) != BLKmode) |
1373 | value = copy_to_reg (value); | |
28d81abb | 1374 | else |
ddbe9812 RS |
1375 | { |
1376 | rtx lab = gen_label_rtx (); | |
4381f7c2 | 1377 | |
ddbe9812 | 1378 | /* Compare the value with itself to reference it. */ |
1574ef13 | 1379 | emit_cmp_and_jump_insns (value, value, EQ, |
84217346 | 1380 | expand_normal (TYPE_SIZE (type)), |
d43e0b7d | 1381 | BLKmode, 0, lab); |
ddbe9812 RS |
1382 | emit_label (lab); |
1383 | } | |
28d81abb RK |
1384 | } |
1385 | ||
4dfa0342 | 1386 | /* Free any temporaries used to evaluate this expression. */ |
28d81abb | 1387 | free_temp_slots (); |
28d81abb RK |
1388 | } |
1389 | ||
1390 | /* Warn if EXP contains any computations whose results are not used. | |
caf93cb0 | 1391 | Return 1 if a warning is printed; 0 otherwise. LOCUS is the |
b9861bff | 1392 | (potential) location of the expression. */ |
28d81abb | 1393 | |
150a992a | 1394 | int |
b9861bff | 1395 | warn_if_unused_value (tree exp, location_t locus) |
28d81abb | 1396 | { |
b9861bff | 1397 | restart: |
591baeb0 | 1398 | if (TREE_USED (exp) || TREE_NO_WARNING (exp)) |
28d81abb RK |
1399 | return 0; |
1400 | ||
9790cefd RH |
1401 | /* Don't warn about void constructs. This includes casting to void, |
1402 | void function calls, and statement expressions with a final cast | |
1403 | to void. */ | |
1404 | if (VOID_TYPE_P (TREE_TYPE (exp))) | |
1405 | return 0; | |
1406 | ||
607bdeaa PB |
1407 | if (EXPR_HAS_LOCATION (exp)) |
1408 | locus = EXPR_LOCATION (exp); | |
b9861bff | 1409 | |
28d81abb RK |
1410 | switch (TREE_CODE (exp)) |
1411 | { | |
1412 | case PREINCREMENT_EXPR: | |
1413 | case POSTINCREMENT_EXPR: | |
1414 | case PREDECREMENT_EXPR: | |
1415 | case POSTDECREMENT_EXPR: | |
1416 | case MODIFY_EXPR: | |
07beea0d | 1417 | case GIMPLE_MODIFY_STMT: |
28d81abb RK |
1418 | case INIT_EXPR: |
1419 | case TARGET_EXPR: | |
1420 | case CALL_EXPR: | |
81797aba | 1421 | case TRY_CATCH_EXPR: |
28d81abb RK |
1422 | case WITH_CLEANUP_EXPR: |
1423 | case EXIT_EXPR: | |
d3d6f724 | 1424 | case VA_ARG_EXPR: |
28d81abb RK |
1425 | return 0; |
1426 | ||
1427 | case BIND_EXPR: | |
1428 | /* For a binding, warn if no side effect within it. */ | |
b9861bff RH |
1429 | exp = BIND_EXPR_BODY (exp); |
1430 | goto restart; | |
28d81abb | 1431 | |
de73f171 | 1432 | case SAVE_EXPR: |
b9861bff RH |
1433 | exp = TREE_OPERAND (exp, 0); |
1434 | goto restart; | |
de73f171 | 1435 | |
28d81abb RK |
1436 | case TRUTH_ORIF_EXPR: |
1437 | case TRUTH_ANDIF_EXPR: | |
1438 | /* In && or ||, warn if 2nd operand has no side effect. */ | |
b9861bff RH |
1439 | exp = TREE_OPERAND (exp, 1); |
1440 | goto restart; | |
28d81abb RK |
1441 | |
1442 | case COMPOUND_EXPR: | |
b9861bff | 1443 | if (warn_if_unused_value (TREE_OPERAND (exp, 0), locus)) |
28d81abb | 1444 | return 1; |
4d23e509 RS |
1445 | /* Let people do `(foo (), 0)' without a warning. */ |
1446 | if (TREE_CONSTANT (TREE_OPERAND (exp, 1))) | |
1447 | return 0; | |
b9861bff RH |
1448 | exp = TREE_OPERAND (exp, 1); |
1449 | goto restart; | |
28d81abb | 1450 | |
591baeb0 JM |
1451 | case COND_EXPR: |
1452 | /* If this is an expression with side effects, don't warn; this | |
1453 | case commonly appears in macro expansions. */ | |
1454 | if (TREE_SIDE_EFFECTS (exp)) | |
28d81abb | 1455 | return 0; |
591baeb0 | 1456 | goto warn; |
28d81abb | 1457 | |
d1e1adfb JM |
1458 | case INDIRECT_REF: |
1459 | /* Don't warn about automatic dereferencing of references, since | |
1460 | the user cannot control it. */ | |
1461 | if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE) | |
b9861bff RH |
1462 | { |
1463 | exp = TREE_OPERAND (exp, 0); | |
1464 | goto restart; | |
1465 | } | |
4381f7c2 KH |
1466 | /* Fall through. */ |
1467 | ||
28d81abb | 1468 | default: |
ddbe9812 | 1469 | /* Referencing a volatile value is a side effect, so don't warn. */ |
6615c446 | 1470 | if ((DECL_P (exp) || REFERENCE_CLASS_P (exp)) |
ddbe9812 RS |
1471 | && TREE_THIS_VOLATILE (exp)) |
1472 | return 0; | |
8d5e6e25 RK |
1473 | |
1474 | /* If this is an expression which has no operands, there is no value | |
1475 | to be unused. There are no such language-independent codes, | |
1476 | but front ends may define such. */ | |
5039610b | 1477 | if (EXPRESSION_CLASS_P (exp) && TREE_OPERAND_LENGTH (exp) == 0) |
8d5e6e25 RK |
1478 | return 0; |
1479 | ||
591baeb0 | 1480 | warn: |
d4ee4d25 | 1481 | warning (0, "%Hvalue computed is not used", &locus); |
28d81abb RK |
1482 | return 1; |
1483 | } | |
1484 | } | |
28d81abb | 1485 | |
28d81abb RK |
1486 | \f |
1487 | /* Generate RTL to return from the current function, with no value. | |
1488 | (That is, we do not do anything about returning any value.) */ | |
1489 | ||
1490 | void | |
46c5ad27 | 1491 | expand_null_return (void) |
28d81abb | 1492 | { |
4381f7c2 | 1493 | /* If this function was declared to return a value, but we |
bd695e1e | 1494 | didn't, clobber the return registers so that they are not |
a1f300c0 | 1495 | propagated live to the rest of the function. */ |
c13fde05 | 1496 | clobber_return_register (); |
28d81abb | 1497 | |
ac45df5d | 1498 | expand_null_return_1 (); |
28d81abb RK |
1499 | } |
1500 | ||
6e3077c6 EB |
1501 | /* Generate RTL to return directly from the current function. |
1502 | (That is, we bypass any return value.) */ | |
1503 | ||
1504 | void | |
1505 | expand_naked_return (void) | |
1506 | { | |
ac45df5d | 1507 | rtx end_label; |
6e3077c6 EB |
1508 | |
1509 | clear_pending_stack_adjust (); | |
1510 | do_pending_stack_adjust (); | |
6e3077c6 | 1511 | |
ac45df5d | 1512 | end_label = naked_return_label; |
6e3077c6 EB |
1513 | if (end_label == 0) |
1514 | end_label = naked_return_label = gen_label_rtx (); | |
ac45df5d RH |
1515 | |
1516 | emit_jump (end_label); | |
6e3077c6 EB |
1517 | } |
1518 | ||
28d81abb RK |
1519 | /* Generate RTL to return from the current function, with value VAL. */ |
1520 | ||
8d800403 | 1521 | static void |
46c5ad27 | 1522 | expand_value_return (rtx val) |
28d81abb | 1523 | { |
28d81abb RK |
1524 | /* Copy the value to the return location |
1525 | unless it's already there. */ | |
1526 | ||
07a236b6 | 1527 | rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl)); |
28d81abb | 1528 | if (return_reg != val) |
77636079 | 1529 | { |
77636079 | 1530 | tree type = TREE_TYPE (DECL_RESULT (current_function_decl)); |
61f71b34 DD |
1531 | if (targetm.calls.promote_function_return (TREE_TYPE (current_function_decl))) |
1532 | { | |
8df83eae | 1533 | int unsignedp = TYPE_UNSIGNED (type); |
61f71b34 DD |
1534 | enum machine_mode old_mode |
1535 | = DECL_MODE (DECL_RESULT (current_function_decl)); | |
1536 | enum machine_mode mode | |
1537 | = promote_mode (type, old_mode, &unsignedp, 1); | |
1538 | ||
1539 | if (mode != old_mode) | |
1540 | val = convert_modes (mode, old_mode, val, unsignedp); | |
1541 | } | |
14a774a9 | 1542 | if (GET_CODE (return_reg) == PARALLEL) |
6e985040 | 1543 | emit_group_load (return_reg, val, type, int_size_in_bytes (type)); |
14a774a9 | 1544 | else |
77636079 RS |
1545 | emit_move_insn (return_reg, val); |
1546 | } | |
14a774a9 | 1547 | |
ac45df5d | 1548 | expand_null_return_1 (); |
28d81abb RK |
1549 | } |
1550 | ||
ac45df5d | 1551 | /* Output a return with no value. */ |
28d81abb RK |
1552 | |
1553 | static void | |
ac45df5d | 1554 | expand_null_return_1 (void) |
28d81abb | 1555 | { |
28d81abb RK |
1556 | clear_pending_stack_adjust (); |
1557 | do_pending_stack_adjust (); | |
526c334b | 1558 | emit_jump (return_label); |
28d81abb RK |
1559 | } |
1560 | \f | |
1561 | /* Generate RTL to evaluate the expression RETVAL and return it | |
1562 | from the current function. */ | |
1563 | ||
1564 | void | |
46c5ad27 | 1565 | expand_return (tree retval) |
28d81abb | 1566 | { |
19e7881c | 1567 | rtx result_rtl; |
b3694847 | 1568 | rtx val = 0; |
28d81abb | 1569 | tree retval_rhs; |
28d81abb RK |
1570 | |
1571 | /* If function wants no value, give it none. */ | |
1572 | if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE) | |
1573 | { | |
84217346 | 1574 | expand_normal (retval); |
28d81abb RK |
1575 | expand_null_return (); |
1576 | return; | |
1577 | } | |
1578 | ||
ea11ca7e | 1579 | if (retval == error_mark_node) |
c9407e4c MM |
1580 | { |
1581 | /* Treat this like a return of no value from a function that | |
1582 | returns a value. */ | |
1583 | expand_null_return (); | |
786de7eb | 1584 | return; |
c9407e4c | 1585 | } |
07beea0d | 1586 | else if ((TREE_CODE (retval) == GIMPLE_MODIFY_STMT |
ac45df5d | 1587 | || TREE_CODE (retval) == INIT_EXPR) |
07beea0d AH |
1588 | && TREE_CODE (GENERIC_TREE_OPERAND (retval, 0)) == RESULT_DECL) |
1589 | retval_rhs = GENERIC_TREE_OPERAND (retval, 1); | |
28d81abb | 1590 | else |
6de9cd9a | 1591 | retval_rhs = retval; |
28d81abb | 1592 | |
19e7881c MM |
1593 | result_rtl = DECL_RTL (DECL_RESULT (current_function_decl)); |
1594 | ||
6f4a43e0 ZW |
1595 | /* If we are returning the RESULT_DECL, then the value has already |
1596 | been stored into it, so we don't have to do anything special. */ | |
1597 | if (TREE_CODE (retval_rhs) == RESULT_DECL) | |
1598 | expand_value_return (result_rtl); | |
1599 | ||
4c485b63 JL |
1600 | /* If the result is an aggregate that is being returned in one (or more) |
1601 | registers, load the registers here. The compiler currently can't handle | |
1602 | copying a BLKmode value into registers. We could put this code in a | |
1603 | more general area (for use by everyone instead of just function | |
1604 | call/return), but until this feature is generally usable it is kept here | |
ac45df5d | 1605 | (and in expand_call). */ |
4c485b63 | 1606 | |
6f4a43e0 | 1607 | else if (retval_rhs != 0 |
07beea0d | 1608 | && TYPE_MODE (GENERIC_TREE_TYPE (retval_rhs)) == BLKmode |
6f4a43e0 | 1609 | && REG_P (result_rtl)) |
4c485b63 | 1610 | { |
770ae6cc RK |
1611 | int i; |
1612 | unsigned HOST_WIDE_INT bitpos, xbitpos; | |
c988af2b | 1613 | unsigned HOST_WIDE_INT padding_correction = 0; |
770ae6cc RK |
1614 | unsigned HOST_WIDE_INT bytes |
1615 | = int_size_in_bytes (TREE_TYPE (retval_rhs)); | |
4c485b63 | 1616 | int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD; |
770ae6cc RK |
1617 | unsigned int bitsize |
1618 | = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), BITS_PER_WORD); | |
703ad42b | 1619 | rtx *result_pseudos = alloca (sizeof (rtx) * n_regs); |
c16ddde3 | 1620 | rtx result_reg, src = NULL_RTX, dst = NULL_RTX; |
84217346 | 1621 | rtx result_val = expand_normal (retval_rhs); |
af55da56 | 1622 | enum machine_mode tmpmode, result_reg_mode; |
4c485b63 | 1623 | |
2954d7db RK |
1624 | if (bytes == 0) |
1625 | { | |
1626 | expand_null_return (); | |
1627 | return; | |
1628 | } | |
1629 | ||
c988af2b RS |
1630 | /* If the structure doesn't take up a whole number of words, see |
1631 | whether the register value should be padded on the left or on | |
1632 | the right. Set PADDING_CORRECTION to the number of padding | |
1633 | bits needed on the left side. | |
1634 | ||
1635 | In most ABIs, the structure will be returned at the least end of | |
1636 | the register, which translates to right padding on little-endian | |
1637 | targets and left padding on big-endian targets. The opposite | |
1638 | holds if the structure is returned at the most significant | |
1639 | end of the register. */ | |
1640 | if (bytes % UNITS_PER_WORD != 0 | |
1641 | && (targetm.calls.return_in_msb (TREE_TYPE (retval_rhs)) | |
1642 | ? !BYTES_BIG_ENDIAN | |
1643 | : BYTES_BIG_ENDIAN)) | |
1644 | padding_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD) | |
1645 | * BITS_PER_UNIT)); | |
a7f875d7 | 1646 | |
4381f7c2 | 1647 | /* Copy the structure BITSIZE bits at a time. */ |
c988af2b | 1648 | for (bitpos = 0, xbitpos = padding_correction; |
a7f875d7 RK |
1649 | bitpos < bytes * BITS_PER_UNIT; |
1650 | bitpos += bitsize, xbitpos += bitsize) | |
4c485b63 | 1651 | { |
a7f875d7 | 1652 | /* We need a new destination pseudo each time xbitpos is |
c988af2b | 1653 | on a word boundary and when xbitpos == padding_correction |
a7f875d7 RK |
1654 | (the first time through). */ |
1655 | if (xbitpos % BITS_PER_WORD == 0 | |
c988af2b | 1656 | || xbitpos == padding_correction) |
4c485b63 | 1657 | { |
a7f875d7 RK |
1658 | /* Generate an appropriate register. */ |
1659 | dst = gen_reg_rtx (word_mode); | |
1660 | result_pseudos[xbitpos / BITS_PER_WORD] = dst; | |
1661 | ||
8a38ed86 AM |
1662 | /* Clear the destination before we move anything into it. */ |
1663 | emit_move_insn (dst, CONST0_RTX (GET_MODE (dst))); | |
4c485b63 | 1664 | } |
a7f875d7 RK |
1665 | |
1666 | /* We need a new source operand each time bitpos is on a word | |
1667 | boundary. */ | |
1668 | if (bitpos % BITS_PER_WORD == 0) | |
1669 | src = operand_subword_force (result_val, | |
1670 | bitpos / BITS_PER_WORD, | |
1671 | BLKmode); | |
1672 | ||
1673 | /* Use bitpos for the source extraction (left justified) and | |
1674 | xbitpos for the destination store (right justified). */ | |
1675 | store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode, | |
1676 | extract_bit_field (src, bitsize, | |
1677 | bitpos % BITS_PER_WORD, 1, | |
b3520980 | 1678 | NULL_RTX, word_mode, word_mode)); |
4c485b63 JL |
1679 | } |
1680 | ||
c988af2b RS |
1681 | tmpmode = GET_MODE (result_rtl); |
1682 | if (tmpmode == BLKmode) | |
1683 | { | |
1684 | /* Find the smallest integer mode large enough to hold the | |
1685 | entire structure and use that mode instead of BLKmode | |
1686 | on the USE insn for the return register. */ | |
1687 | for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT); | |
1688 | tmpmode != VOIDmode; | |
1689 | tmpmode = GET_MODE_WIDER_MODE (tmpmode)) | |
1690 | /* Have we found a large enough mode? */ | |
1691 | if (GET_MODE_SIZE (tmpmode) >= bytes) | |
1692 | break; | |
4c485b63 | 1693 | |
41374e13 NS |
1694 | /* A suitable mode should have been found. */ |
1695 | gcc_assert (tmpmode != VOIDmode); | |
4c485b63 | 1696 | |
c988af2b RS |
1697 | PUT_MODE (result_rtl, tmpmode); |
1698 | } | |
3ffeb8f1 | 1699 | |
af55da56 JW |
1700 | if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode)) |
1701 | result_reg_mode = word_mode; | |
1702 | else | |
1703 | result_reg_mode = tmpmode; | |
1704 | result_reg = gen_reg_rtx (result_reg_mode); | |
1705 | ||
3ffeb8f1 | 1706 | for (i = 0; i < n_regs; i++) |
af55da56 | 1707 | emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode), |
3ffeb8f1 | 1708 | result_pseudos[i]); |
4c485b63 | 1709 | |
af55da56 JW |
1710 | if (tmpmode != result_reg_mode) |
1711 | result_reg = gen_lowpart (tmpmode, result_reg); | |
1712 | ||
4c485b63 JL |
1713 | expand_value_return (result_reg); |
1714 | } | |
7cc8342c RH |
1715 | else if (retval_rhs != 0 |
1716 | && !VOID_TYPE_P (TREE_TYPE (retval_rhs)) | |
f8cfc6aa | 1717 | && (REG_P (result_rtl) |
7cc8342c | 1718 | || (GET_CODE (result_rtl) == PARALLEL))) |
28d81abb | 1719 | { |
14a774a9 RK |
1720 | /* Calculate the return value into a temporary (usually a pseudo |
1721 | reg). */ | |
1da68f56 RK |
1722 | tree ot = TREE_TYPE (DECL_RESULT (current_function_decl)); |
1723 | tree nt = build_qualified_type (ot, TYPE_QUALS (ot) | TYPE_QUAL_CONST); | |
1724 | ||
1725 | val = assign_temp (nt, 0, 0, 1); | |
49452c07 | 1726 | val = expand_expr (retval_rhs, val, GET_MODE (val), EXPAND_NORMAL); |
dd98f85c | 1727 | val = force_not_mem (val); |
ac45df5d | 1728 | /* Return the calculated value. */ |
bef5d8b6 | 1729 | expand_value_return (val); |
28d81abb RK |
1730 | } |
1731 | else | |
1732 | { | |
ac45df5d | 1733 | /* No hard reg used; calculate value into hard return reg. */ |
49452c07 | 1734 | expand_expr (retval, const0_rtx, VOIDmode, EXPAND_NORMAL); |
14a774a9 | 1735 | expand_value_return (result_rtl); |
28d81abb RK |
1736 | } |
1737 | } | |
28d81abb | 1738 | \f |
0e9e1e0a | 1739 | /* Given a pointer to a BLOCK node return nonzero if (and only if) the node |
deb5e280 JM |
1740 | in question represents the outermost pair of curly braces (i.e. the "body |
1741 | block") of a function or method. | |
1742 | ||
1743 | For any BLOCK node representing a "body block" of a function or method, the | |
1744 | BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which | |
1745 | represents the outermost (function) scope for the function or method (i.e. | |
1746 | the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of | |
4381f7c2 | 1747 | *that* node in turn will point to the relevant FUNCTION_DECL node. */ |
deb5e280 JM |
1748 | |
1749 | int | |
46c5ad27 | 1750 | is_body_block (tree stmt) |
deb5e280 | 1751 | { |
2896d056 ZW |
1752 | if (lang_hooks.no_body_blocks) |
1753 | return 0; | |
1754 | ||
deb5e280 JM |
1755 | if (TREE_CODE (stmt) == BLOCK) |
1756 | { | |
1757 | tree parent = BLOCK_SUPERCONTEXT (stmt); | |
1758 | ||
1759 | if (parent && TREE_CODE (parent) == BLOCK) | |
1760 | { | |
1761 | tree grandparent = BLOCK_SUPERCONTEXT (parent); | |
1762 | ||
1763 | if (grandparent && TREE_CODE (grandparent) == FUNCTION_DECL) | |
1764 | return 1; | |
1765 | } | |
1766 | } | |
1767 | ||
1768 | return 0; | |
1769 | } | |
1770 | ||
ba716ac9 BS |
1771 | /* Emit code to restore vital registers at the beginning of a nonlocal goto |
1772 | handler. */ | |
1773 | static void | |
46c5ad27 | 1774 | expand_nl_goto_receiver (void) |
ba716ac9 | 1775 | { |
6de9cd9a | 1776 | /* Clobber the FP when we get here, so we have to make sure it's |
e292dbb0 WH |
1777 | marked as used by this function. */ |
1778 | emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx)); | |
1779 | ||
1780 | /* Mark the static chain as clobbered here so life information | |
1781 | doesn't get messed up for it. */ | |
1782 | emit_insn (gen_rtx_CLOBBER (VOIDmode, static_chain_rtx)); | |
1783 | ||
ba716ac9 BS |
1784 | #ifdef HAVE_nonlocal_goto |
1785 | if (! HAVE_nonlocal_goto) | |
1786 | #endif | |
1787 | /* First adjust our frame pointer to its actual value. It was | |
1788 | previously set to the start of the virtual area corresponding to | |
1789 | the stacked variables when we branched here and now needs to be | |
1790 | adjusted to the actual hardware fp value. | |
1791 | ||
1792 | Assignments are to virtual registers are converted by | |
1793 | instantiate_virtual_regs into the corresponding assignment | |
1794 | to the underlying register (fp in this case) that makes | |
1795 | the original assignment true. | |
1796 | So the following insn will actually be | |
1797 | decrementing fp by STARTING_FRAME_OFFSET. */ | |
1798 | emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx); | |
1799 | ||
1800 | #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM | |
1801 | if (fixed_regs[ARG_POINTER_REGNUM]) | |
1802 | { | |
1803 | #ifdef ELIMINABLE_REGS | |
1804 | /* If the argument pointer can be eliminated in favor of the | |
1805 | frame pointer, we don't need to restore it. We assume here | |
1806 | that if such an elimination is present, it can always be used. | |
1807 | This is the case on all known machines; if we don't make this | |
1808 | assumption, we do unnecessary saving on many machines. */ | |
8b60264b | 1809 | static const struct elims {const int from, to;} elim_regs[] = ELIMINABLE_REGS; |
ba716ac9 BS |
1810 | size_t i; |
1811 | ||
b6a1cbae | 1812 | for (i = 0; i < ARRAY_SIZE (elim_regs); i++) |
ba716ac9 BS |
1813 | if (elim_regs[i].from == ARG_POINTER_REGNUM |
1814 | && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM) | |
1815 | break; | |
1816 | ||
b6a1cbae | 1817 | if (i == ARRAY_SIZE (elim_regs)) |
ba716ac9 BS |
1818 | #endif |
1819 | { | |
1820 | /* Now restore our arg pointer from the address at which it | |
278ed218 | 1821 | was saved in our stack frame. */ |
ba716ac9 | 1822 | emit_move_insn (virtual_incoming_args_rtx, |
278ed218 | 1823 | copy_to_reg (get_arg_pointer_save_area (cfun))); |
ba716ac9 BS |
1824 | } |
1825 | } | |
1826 | #endif | |
1827 | ||
1828 | #ifdef HAVE_nonlocal_goto_receiver | |
1829 | if (HAVE_nonlocal_goto_receiver) | |
1830 | emit_insn (gen_nonlocal_goto_receiver ()); | |
1831 | #endif | |
e292dbb0 | 1832 | |
6fb5fa3c DB |
1833 | /* We must not allow the code we just generated to be reordered by |
1834 | scheduling. Specifically, the update of the frame pointer must | |
1835 | happen immediately, not later. */ | |
1836 | emit_insn (gen_blockage ()); | |
ba716ac9 | 1837 | } |
28d81abb RK |
1838 | \f |
1839 | /* Generate RTL for the automatic variable declaration DECL. | |
ec5cd386 | 1840 | (Other kinds of declarations are simply ignored if seen here.) */ |
28d81abb RK |
1841 | |
1842 | void | |
46c5ad27 | 1843 | expand_decl (tree decl) |
28d81abb | 1844 | { |
ca695ac9 JB |
1845 | tree type; |
1846 | ||
ca695ac9 | 1847 | type = TREE_TYPE (decl); |
28d81abb | 1848 | |
eabb9ed0 RK |
1849 | /* For a CONST_DECL, set mode, alignment, and sizes from those of the |
1850 | type in case this node is used in a reference. */ | |
1851 | if (TREE_CODE (decl) == CONST_DECL) | |
1852 | { | |
1853 | DECL_MODE (decl) = TYPE_MODE (type); | |
1854 | DECL_ALIGN (decl) = TYPE_ALIGN (type); | |
1855 | DECL_SIZE (decl) = TYPE_SIZE (type); | |
1856 | DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (type); | |
1857 | return; | |
1858 | } | |
28d81abb | 1859 | |
eabb9ed0 RK |
1860 | /* Otherwise, only automatic variables need any expansion done. Static and |
1861 | external variables, and external functions, will be handled by | |
1862 | `assemble_variable' (called from finish_decl). TYPE_DECL requires | |
1863 | nothing. PARM_DECLs are handled in `assign_parms'. */ | |
28d81abb RK |
1864 | if (TREE_CODE (decl) != VAR_DECL) |
1865 | return; | |
eabb9ed0 | 1866 | |
44fe2e80 | 1867 | if (TREE_STATIC (decl) || DECL_EXTERNAL (decl)) |
28d81abb RK |
1868 | return; |
1869 | ||
1870 | /* Create the RTL representation for the variable. */ | |
1871 | ||
1872 | if (type == error_mark_node) | |
19e7881c | 1873 | SET_DECL_RTL (decl, gen_rtx_MEM (BLKmode, const0_rtx)); |
1da68f56 | 1874 | |
28d81abb RK |
1875 | else if (DECL_SIZE (decl) == 0) |
1876 | /* Variable with incomplete type. */ | |
1877 | { | |
abde42f7 | 1878 | rtx x; |
28d81abb RK |
1879 | if (DECL_INITIAL (decl) == 0) |
1880 | /* Error message was already done; now avoid a crash. */ | |
abde42f7 | 1881 | x = gen_rtx_MEM (BLKmode, const0_rtx); |
28d81abb RK |
1882 | else |
1883 | /* An initializer is going to decide the size of this array. | |
1884 | Until we know the size, represent its address with a reg. */ | |
abde42f7 | 1885 | x = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode)); |
3bdf5ad1 | 1886 | |
abde42f7 JH |
1887 | set_mem_attributes (x, decl, 1); |
1888 | SET_DECL_RTL (decl, x); | |
28d81abb | 1889 | } |
8fff4fc1 | 1890 | else if (use_register_for_decl (decl)) |
28d81abb RK |
1891 | { |
1892 | /* Automatic variable that can go in a register. */ | |
8df83eae | 1893 | int unsignedp = TYPE_UNSIGNED (type); |
28612f9e RK |
1894 | enum machine_mode reg_mode |
1895 | = promote_mode (type, DECL_MODE (decl), &unsignedp, 0); | |
98f3b471 | 1896 | |
19e7881c | 1897 | SET_DECL_RTL (decl, gen_reg_rtx (reg_mode)); |
0d4903b8 | 1898 | |
0b068ee9 | 1899 | /* Note if the object is a user variable. */ |
7dc8b126 | 1900 | if (!DECL_ARTIFICIAL (decl)) |
0b068ee9 JL |
1901 | { |
1902 | mark_user_reg (DECL_RTL (decl)); | |
1903 | ||
1904 | /* Trust user variables which have a pointer type to really | |
1905 | be pointers. Do not trust compiler generated temporaries | |
1906 | as our type system is totally busted as it relates to | |
1907 | pointer arithmetic which translates into lots of compiler | |
1908 | generated objects with pointer types, but which are not really | |
1909 | pointers. */ | |
1910 | if (POINTER_TYPE_P (type)) | |
1911 | mark_reg_pointer (DECL_RTL (decl), | |
1912 | TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl)))); | |
1913 | } | |
28d81abb | 1914 | } |
0df15c2c | 1915 | |
4559fd9e | 1916 | else if (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST |
5e4ef18a | 1917 | && ! (flag_stack_check && ! STACK_CHECK_BUILTIN |
05bccae2 RK |
1918 | && 0 < compare_tree_int (DECL_SIZE_UNIT (decl), |
1919 | STACK_CHECK_MAX_VAR_SIZE))) | |
28d81abb RK |
1920 | { |
1921 | /* Variable of fixed size that goes on the stack. */ | |
1922 | rtx oldaddr = 0; | |
1923 | rtx addr; | |
0d4903b8 | 1924 | rtx x; |
28d81abb RK |
1925 | |
1926 | /* If we previously made RTL for this decl, it must be an array | |
1927 | whose size was determined by the initializer. | |
1928 | The old address was a register; set that register now | |
1929 | to the proper address. */ | |
19e7881c | 1930 | if (DECL_RTL_SET_P (decl)) |
28d81abb | 1931 | { |
41374e13 NS |
1932 | gcc_assert (MEM_P (DECL_RTL (decl))); |
1933 | gcc_assert (REG_P (XEXP (DECL_RTL (decl), 0))); | |
28d81abb RK |
1934 | oldaddr = XEXP (DECL_RTL (decl), 0); |
1935 | } | |
1936 | ||
28d81abb RK |
1937 | /* Set alignment we actually gave this decl. */ |
1938 | DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT | |
1939 | : GET_MODE_BITSIZE (DECL_MODE (decl))); | |
11cf4d18 | 1940 | DECL_USER_ALIGN (decl) = 0; |
28d81abb | 1941 | |
9432c136 | 1942 | x = assign_temp (decl, 1, 1, 1); |
0d4903b8 RK |
1943 | set_mem_attributes (x, decl, 1); |
1944 | SET_DECL_RTL (decl, x); | |
1945 | ||
28d81abb RK |
1946 | if (oldaddr) |
1947 | { | |
1948 | addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr); | |
1949 | if (addr != oldaddr) | |
1950 | emit_move_insn (oldaddr, addr); | |
1951 | } | |
28d81abb RK |
1952 | } |
1953 | else | |
1954 | /* Dynamic-size object: must push space on the stack. */ | |
1955 | { | |
abde42f7 | 1956 | rtx address, size, x; |
28d81abb RK |
1957 | |
1958 | /* Record the stack pointer on entry to block, if have | |
1959 | not already done so. */ | |
7393c642 | 1960 | do_pending_stack_adjust (); |
28d81abb | 1961 | |
1c9766da RK |
1962 | /* Compute the variable's size, in bytes. This will expand any |
1963 | needed SAVE_EXPRs for the first time. */ | |
84217346 | 1964 | size = expand_normal (DECL_SIZE_UNIT (decl)); |
28d81abb RK |
1965 | free_temp_slots (); |
1966 | ||
ff91ad08 | 1967 | /* Allocate space on the stack for the variable. Note that |
4381f7c2 | 1968 | DECL_ALIGN says how the variable is to be aligned and we |
ff91ad08 RK |
1969 | cannot use it to conclude anything about the alignment of |
1970 | the size. */ | |
37366632 | 1971 | address = allocate_dynamic_stack_space (size, NULL_RTX, |
ff91ad08 | 1972 | TYPE_ALIGN (TREE_TYPE (decl))); |
28d81abb | 1973 | |
28d81abb | 1974 | /* Reference the variable indirect through that rtx. */ |
abde42f7 JH |
1975 | x = gen_rtx_MEM (DECL_MODE (decl), address); |
1976 | set_mem_attributes (x, decl, 1); | |
1977 | SET_DECL_RTL (decl, x); | |
28d81abb | 1978 | |
2207e295 | 1979 | |
28d81abb RK |
1980 | /* Indicate the alignment we actually gave this variable. */ |
1981 | #ifdef STACK_BOUNDARY | |
1982 | DECL_ALIGN (decl) = STACK_BOUNDARY; | |
1983 | #else | |
1984 | DECL_ALIGN (decl) = BIGGEST_ALIGNMENT; | |
1985 | #endif | |
11cf4d18 | 1986 | DECL_USER_ALIGN (decl) = 0; |
28d81abb | 1987 | } |
28d81abb RK |
1988 | } |
1989 | \f | |
6de9cd9a DN |
1990 | /* Emit code to save the current value of stack. */ |
1991 | rtx | |
1992 | expand_stack_save (void) | |
1993 | { | |
1994 | rtx ret = NULL_RTX; | |
1995 | ||
1996 | do_pending_stack_adjust (); | |
1997 | emit_stack_save (SAVE_BLOCK, &ret, NULL_RTX); | |
1998 | return ret; | |
1999 | } | |
2000 | ||
2001 | /* Emit code to restore the current value of stack. */ | |
2002 | void | |
2003 | expand_stack_restore (tree var) | |
2004 | { | |
2005 | rtx sa = DECL_RTL (var); | |
2006 | ||
2007 | emit_stack_restore (SAVE_BLOCK, sa, NULL_RTX); | |
2008 | } | |
28d81abb RK |
2009 | \f |
2010 | /* DECL is an anonymous union. CLEANUP is a cleanup for DECL. | |
2011 | DECL_ELTS is the list of elements that belong to DECL's type. | |
2012 | In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */ | |
2013 | ||
2014 | void | |
ac45df5d RH |
2015 | expand_anon_union_decl (tree decl, tree cleanup ATTRIBUTE_UNUSED, |
2016 | tree decl_elts) | |
28d81abb | 2017 | { |
28d81abb | 2018 | rtx x; |
8a693bd0 | 2019 | tree t; |
28d81abb | 2020 | |
8a693bd0 MM |
2021 | /* If any of the elements are addressable, so is the entire union. */ |
2022 | for (t = decl_elts; t; t = TREE_CHAIN (t)) | |
2023 | if (TREE_ADDRESSABLE (TREE_VALUE (t))) | |
2024 | { | |
2025 | TREE_ADDRESSABLE (decl) = 1; | |
2026 | break; | |
2027 | } | |
4381f7c2 | 2028 | |
ec5cd386 | 2029 | expand_decl (decl); |
28d81abb RK |
2030 | x = DECL_RTL (decl); |
2031 | ||
8a693bd0 MM |
2032 | /* Go through the elements, assigning RTL to each. */ |
2033 | for (t = decl_elts; t; t = TREE_CHAIN (t)) | |
28d81abb | 2034 | { |
8a693bd0 | 2035 | tree decl_elt = TREE_VALUE (t); |
28d81abb | 2036 | enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt)); |
41374e13 | 2037 | rtx decl_rtl; |
28d81abb | 2038 | |
3256b817 JJ |
2039 | /* If any of the elements are addressable, so is the entire |
2040 | union. */ | |
2041 | if (TREE_USED (decl_elt)) | |
2042 | TREE_USED (decl) = 1; | |
2043 | ||
7b9032dd JM |
2044 | /* Propagate the union's alignment to the elements. */ |
2045 | DECL_ALIGN (decl_elt) = DECL_ALIGN (decl); | |
11cf4d18 | 2046 | DECL_USER_ALIGN (decl_elt) = DECL_USER_ALIGN (decl); |
7b9032dd JM |
2047 | |
2048 | /* If the element has BLKmode and the union doesn't, the union is | |
2049 | aligned such that the element doesn't need to have BLKmode, so | |
2050 | change the element's mode to the appropriate one for its size. */ | |
2051 | if (mode == BLKmode && DECL_MODE (decl) != BLKmode) | |
2052 | DECL_MODE (decl_elt) = mode | |
05bccae2 | 2053 | = mode_for_size_tree (DECL_SIZE (decl_elt), MODE_INT, 1); |
7b9032dd | 2054 | |
41374e13 NS |
2055 | if (mode == GET_MODE (x)) |
2056 | decl_rtl = x; | |
2057 | else if (MEM_P (x)) | |
2058 | /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we | |
2059 | instead create a new MEM rtx with the proper mode. */ | |
2060 | decl_rtl = adjust_address_nv (x, mode, 0); | |
2061 | else | |
28d81abb | 2062 | { |
41374e13 NS |
2063 | gcc_assert (REG_P (x)); |
2064 | decl_rtl = gen_lowpart_SUBREG (mode, x); | |
28d81abb | 2065 | } |
41374e13 | 2066 | SET_DECL_RTL (decl_elt, decl_rtl); |
28d81abb RK |
2067 | } |
2068 | } | |
2069 | \f | |
7efcb746 PB |
2070 | /* Do the insertion of a case label into case_list. The labels are |
2071 | fed to us in descending order from the sorted vector of case labels used | |
a6c0a76c | 2072 | in the tree part of the middle end. So the list we construct is |
eb172681 RS |
2073 | sorted in ascending order. The bounds on the case range, LOW and HIGH, |
2074 | are converted to case's index type TYPE. */ | |
57641239 | 2075 | |
eb172681 RS |
2076 | static struct case_node * |
2077 | add_case_node (struct case_node *head, tree type, tree low, tree high, | |
2078 | tree label) | |
57641239 | 2079 | { |
eb172681 | 2080 | tree min_value, max_value; |
a6c0a76c | 2081 | struct case_node *r; |
57641239 | 2082 | |
eb172681 RS |
2083 | gcc_assert (TREE_CODE (low) == INTEGER_CST); |
2084 | gcc_assert (!high || TREE_CODE (high) == INTEGER_CST); | |
2085 | ||
2086 | min_value = TYPE_MIN_VALUE (type); | |
2087 | max_value = TYPE_MAX_VALUE (type); | |
2088 | ||
56cb9733 MM |
2089 | /* If there's no HIGH value, then this is not a case range; it's |
2090 | just a simple case label. But that's just a degenerate case | |
a6c0a76c SB |
2091 | range. |
2092 | If the bounds are equal, turn this into the one-value case. */ | |
2093 | if (!high || tree_int_cst_equal (low, high)) | |
eb172681 RS |
2094 | { |
2095 | /* If the simple case value is unreachable, ignore it. */ | |
b77aa1f7 AP |
2096 | if ((TREE_CODE (min_value) == INTEGER_CST |
2097 | && tree_int_cst_compare (low, min_value) < 0) | |
2098 | || (TREE_CODE (max_value) == INTEGER_CST | |
2099 | && tree_int_cst_compare (low, max_value) > 0)) | |
eb172681 RS |
2100 | return head; |
2101 | low = fold_convert (type, low); | |
2102 | high = low; | |
2103 | } | |
2104 | else | |
2105 | { | |
2106 | /* If the entire case range is unreachable, ignore it. */ | |
b77aa1f7 AP |
2107 | if ((TREE_CODE (min_value) == INTEGER_CST |
2108 | && tree_int_cst_compare (high, min_value) < 0) | |
2109 | || (TREE_CODE (max_value) == INTEGER_CST | |
2110 | && tree_int_cst_compare (low, max_value) > 0)) | |
eb172681 RS |
2111 | return head; |
2112 | ||
2113 | /* If the lower bound is less than the index type's minimum | |
2114 | value, truncate the range bounds. */ | |
b77aa1f7 AP |
2115 | if (TREE_CODE (min_value) == INTEGER_CST |
2116 | && tree_int_cst_compare (low, min_value) < 0) | |
eb172681 RS |
2117 | low = min_value; |
2118 | low = fold_convert (type, low); | |
2119 | ||
2120 | /* If the upper bound is greater than the index type's maximum | |
2121 | value, truncate the range bounds. */ | |
b77aa1f7 AP |
2122 | if (TREE_CODE (max_value) == INTEGER_CST |
2123 | && tree_int_cst_compare (high, max_value) > 0) | |
eb172681 RS |
2124 | high = max_value; |
2125 | high = fold_convert (type, high); | |
2126 | } | |
2127 | ||
56cb9733 | 2128 | |
b2ecb7a8 | 2129 | /* Add this label to the chain. Make sure to drop overflow flags. */ |
703ad42b | 2130 | r = ggc_alloc (sizeof (struct case_node)); |
b2ecb7a8 RG |
2131 | r->low = build_int_cst_wide (TREE_TYPE (low), TREE_INT_CST_LOW (low), |
2132 | TREE_INT_CST_HIGH (low)); | |
2133 | r->high = build_int_cst_wide (TREE_TYPE (high), TREE_INT_CST_LOW (high), | |
2134 | TREE_INT_CST_HIGH (high)); | |
57641239 | 2135 | r->code_label = label; |
a6c0a76c | 2136 | r->parent = r->left = NULL; |
7efcb746 PB |
2137 | r->right = head; |
2138 | return r; | |
28d81abb | 2139 | } |
28d81abb | 2140 | \f |
9bb231fd RS |
2141 | /* Maximum number of case bit tests. */ |
2142 | #define MAX_CASE_BIT_TESTS 3 | |
2143 | ||
2144 | /* By default, enable case bit tests on targets with ashlsi3. */ | |
2145 | #ifndef CASE_USE_BIT_TESTS | |
2146 | #define CASE_USE_BIT_TESTS (ashl_optab->handlers[word_mode].insn_code \ | |
2147 | != CODE_FOR_nothing) | |
2148 | #endif | |
2149 | ||
2150 | ||
2151 | /* A case_bit_test represents a set of case nodes that may be | |
2152 | selected from using a bit-wise comparison. HI and LO hold | |
2153 | the integer to be tested against, LABEL contains the label | |
2154 | to jump to upon success and BITS counts the number of case | |
2155 | nodes handled by this test, typically the number of bits | |
2156 | set in HI:LO. */ | |
2157 | ||
2158 | struct case_bit_test | |
2159 | { | |
2160 | HOST_WIDE_INT hi; | |
2161 | HOST_WIDE_INT lo; | |
2162 | rtx label; | |
2163 | int bits; | |
2164 | }; | |
2165 | ||
2166 | /* Determine whether "1 << x" is relatively cheap in word_mode. */ | |
2167 | ||
7e51717c AJ |
2168 | static |
2169 | bool lshift_cheap_p (void) | |
9bb231fd RS |
2170 | { |
2171 | static bool init = false; | |
2172 | static bool cheap = true; | |
2173 | ||
2174 | if (!init) | |
2175 | { | |
2176 | rtx reg = gen_rtx_REG (word_mode, 10000); | |
2177 | int cost = rtx_cost (gen_rtx_ASHIFT (word_mode, const1_rtx, reg), SET); | |
2178 | cheap = cost < COSTS_N_INSNS (3); | |
2179 | init = true; | |
2180 | } | |
2181 | ||
2182 | return cheap; | |
2183 | } | |
2184 | ||
2185 | /* Comparison function for qsort to order bit tests by decreasing | |
2186 | number of case nodes, i.e. the node with the most cases gets | |
2187 | tested first. */ | |
2188 | ||
f667741c SB |
2189 | static int |
2190 | case_bit_test_cmp (const void *p1, const void *p2) | |
9bb231fd RS |
2191 | { |
2192 | const struct case_bit_test *d1 = p1; | |
2193 | const struct case_bit_test *d2 = p2; | |
2194 | ||
0174997a RS |
2195 | if (d2->bits != d1->bits) |
2196 | return d2->bits - d1->bits; | |
2197 | ||
2198 | /* Stabilize the sort. */ | |
2199 | return CODE_LABEL_NUMBER (d2->label) - CODE_LABEL_NUMBER (d1->label); | |
9bb231fd RS |
2200 | } |
2201 | ||
2202 | /* Expand a switch statement by a short sequence of bit-wise | |
2203 | comparisons. "switch(x)" is effectively converted into | |
2204 | "if ((1 << (x-MINVAL)) & CST)" where CST and MINVAL are | |
2205 | integer constants. | |
2206 | ||
2207 | INDEX_EXPR is the value being switched on, which is of | |
2208 | type INDEX_TYPE. MINVAL is the lowest case value of in | |
2209 | the case nodes, of INDEX_TYPE type, and RANGE is highest | |
2210 | value minus MINVAL, also of type INDEX_TYPE. NODES is | |
2211 | the set of case nodes, and DEFAULT_LABEL is the label to | |
2212 | branch to should none of the cases match. | |
2213 | ||
2214 | There *MUST* be MAX_CASE_BIT_TESTS or less unique case | |
2215 | node targets. */ | |
2216 | ||
2217 | static void | |
46c5ad27 AJ |
2218 | emit_case_bit_tests (tree index_type, tree index_expr, tree minval, |
2219 | tree range, case_node_ptr nodes, rtx default_label) | |
9bb231fd RS |
2220 | { |
2221 | struct case_bit_test test[MAX_CASE_BIT_TESTS]; | |
2222 | enum machine_mode mode; | |
2223 | rtx expr, index, label; | |
2224 | unsigned int i,j,lo,hi; | |
2225 | struct case_node *n; | |
2226 | unsigned int count; | |
2227 | ||
2228 | count = 0; | |
2229 | for (n = nodes; n; n = n->right) | |
2230 | { | |
2231 | label = label_rtx (n->code_label); | |
2232 | for (i = 0; i < count; i++) | |
7efcb746 | 2233 | if (label == test[i].label) |
9bb231fd RS |
2234 | break; |
2235 | ||
2236 | if (i == count) | |
2237 | { | |
41374e13 NS |
2238 | gcc_assert (count < MAX_CASE_BIT_TESTS); |
2239 | test[i].hi = 0; | |
2240 | test[i].lo = 0; | |
9bb231fd RS |
2241 | test[i].label = label; |
2242 | test[i].bits = 1; | |
2243 | count++; | |
2244 | } | |
2245 | else | |
2246 | test[i].bits++; | |
2247 | ||
4845b383 KH |
2248 | lo = tree_low_cst (fold_build2 (MINUS_EXPR, index_type, |
2249 | n->low, minval), 1); | |
2250 | hi = tree_low_cst (fold_build2 (MINUS_EXPR, index_type, | |
2251 | n->high, minval), 1); | |
9bb231fd RS |
2252 | for (j = lo; j <= hi; j++) |
2253 | if (j >= HOST_BITS_PER_WIDE_INT) | |
2254 | test[i].hi |= (HOST_WIDE_INT) 1 << (j - HOST_BITS_PER_INT); | |
2255 | else | |
2256 | test[i].lo |= (HOST_WIDE_INT) 1 << j; | |
2257 | } | |
2258 | ||
2259 | qsort (test, count, sizeof(*test), case_bit_test_cmp); | |
2260 | ||
4845b383 KH |
2261 | index_expr = fold_build2 (MINUS_EXPR, index_type, |
2262 | fold_convert (index_type, index_expr), | |
2263 | fold_convert (index_type, minval)); | |
84217346 | 2264 | index = expand_normal (index_expr); |
9bb231fd RS |
2265 | do_pending_stack_adjust (); |
2266 | ||
2267 | mode = TYPE_MODE (index_type); | |
84217346 | 2268 | expr = expand_normal (range); |
9bb231fd RS |
2269 | emit_cmp_and_jump_insns (index, expr, GTU, NULL_RTX, mode, 1, |
2270 | default_label); | |
2271 | ||
2272 | index = convert_to_mode (word_mode, index, 0); | |
2273 | index = expand_binop (word_mode, ashl_optab, const1_rtx, | |
2274 | index, NULL_RTX, 1, OPTAB_WIDEN); | |
2275 | ||
2276 | for (i = 0; i < count; i++) | |
2277 | { | |
2278 | expr = immed_double_const (test[i].lo, test[i].hi, word_mode); | |
2279 | expr = expand_binop (word_mode, and_optab, index, expr, | |
2280 | NULL_RTX, 1, OPTAB_WIDEN); | |
2281 | emit_cmp_and_jump_insns (expr, const0_rtx, NE, NULL_RTX, | |
2282 | word_mode, 1, test[i].label); | |
2283 | } | |
2284 | ||
2285 | emit_jump (default_label); | |
2286 | } | |
ad82abb8 | 2287 | |
41cbdcd0 KH |
2288 | #ifndef HAVE_casesi |
2289 | #define HAVE_casesi 0 | |
2290 | #endif | |
2291 | ||
2292 | #ifndef HAVE_tablejump | |
2293 | #define HAVE_tablejump 0 | |
2294 | #endif | |
2295 | ||
3feaea00 | 2296 | /* Terminate a case (Pascal/Ada) or switch (C) statement |
9ab0ddd7 | 2297 | in which ORIG_INDEX is the expression to be tested. |
6f9fdf4d JJ |
2298 | If ORIG_TYPE is not NULL, it is the original ORIG_INDEX |
2299 | type as given in the source before any compiler conversions. | |
28d81abb RK |
2300 | Generate the code to test it and jump to the right place. */ |
2301 | ||
2302 | void | |
7efcb746 | 2303 | expand_case (tree exp) |
28d81abb | 2304 | { |
9fb60a0d | 2305 | tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE; |
28d81abb | 2306 | rtx default_label = 0; |
4cfa46c8 | 2307 | struct case_node *n; |
9bb231fd | 2308 | unsigned int count, uniq; |
28d81abb | 2309 | rtx index; |
ca695ac9 | 2310 | rtx table_label; |
28d81abb RK |
2311 | int ncases; |
2312 | rtx *labelvec; | |
a38e7aa5 | 2313 | int i; |
9bb231fd | 2314 | rtx before_case, end, lab; |
ca695ac9 | 2315 | |
7efcb746 PB |
2316 | tree vec = SWITCH_LABELS (exp); |
2317 | tree orig_type = TREE_TYPE (exp); | |
2318 | tree index_expr = SWITCH_COND (exp); | |
2319 | tree index_type = TREE_TYPE (index_expr); | |
2320 | int unsignedp = TYPE_UNSIGNED (index_type); | |
2321 | ||
2322 | /* The insn after which the case dispatch should finally | |
2323 | be emitted. Zero for a dummy. */ | |
2324 | rtx start; | |
2325 | ||
2326 | /* A list of case labels; it is first built as a list and it may then | |
2327 | be rearranged into a nearly balanced binary tree. */ | |
2328 | struct case_node *case_list = 0; | |
2329 | ||
2330 | /* Label to jump to if no case matches. */ | |
4e0148df | 2331 | tree default_label_decl; |
7efcb746 PB |
2332 | |
2333 | /* The switch body is lowered in gimplify.c, we should never have | |
2334 | switches with a non-NULL SWITCH_BODY here. */ | |
41374e13 NS |
2335 | gcc_assert (!SWITCH_BODY (exp)); |
2336 | gcc_assert (SWITCH_LABELS (exp)); | |
03c03770 | 2337 | |
28d81abb RK |
2338 | do_pending_stack_adjust (); |
2339 | ||
2340 | /* An ERROR_MARK occurs for various reasons including invalid data type. */ | |
1b0cb6fc | 2341 | if (index_type != error_mark_node) |
28d81abb | 2342 | { |
4e0148df | 2343 | tree elt; |
4cfa46c8 | 2344 | bitmap label_bitmap; |
eb172681 | 2345 | |
5100d114 KH |
2346 | /* cleanup_tree_cfg removes all SWITCH_EXPR with their index |
2347 | expressions being INTEGER_CST. */ | |
2348 | gcc_assert (TREE_CODE (index_expr) != INTEGER_CST); | |
2349 | ||
4e0148df KH |
2350 | /* The default case is at the end of TREE_VEC. */ |
2351 | elt = TREE_VEC_ELT (vec, TREE_VEC_LENGTH (vec) - 1); | |
2352 | gcc_assert (!CASE_HIGH (elt)); | |
2353 | gcc_assert (!CASE_LOW (elt)); | |
2354 | default_label_decl = CASE_LABEL (elt); | |
2355 | ||
2356 | for (i = TREE_VEC_LENGTH (vec) - 1; --i >= 0; ) | |
2357 | { | |
3feaea00 | 2358 | tree low, high; |
4e0148df | 2359 | elt = TREE_VEC_ELT (vec, i); |
3feaea00 EB |
2360 | |
2361 | low = CASE_LOW (elt); | |
2362 | gcc_assert (low); | |
2363 | high = CASE_HIGH (elt); | |
2364 | ||
2365 | /* Discard empty ranges. */ | |
2366 | if (high && INT_CST_LT (high, low)) | |
2367 | continue; | |
2368 | ||
2369 | case_list = add_case_node (case_list, index_type, low, high, | |
4e0148df | 2370 | CASE_LABEL (elt)); |
eb172681 RS |
2371 | } |
2372 | ||
2373 | ||
ede497cf | 2374 | before_case = start = get_last_insn (); |
7efcb746 | 2375 | default_label = label_rtx (default_label_decl); |
28d81abb | 2376 | |
5cfffc4e | 2377 | /* Get upper and lower bounds of case values. */ |
28d81abb | 2378 | |
9bb231fd | 2379 | uniq = 0; |
28d81abb | 2380 | count = 0; |
8bdbfff5 | 2381 | label_bitmap = BITMAP_ALLOC (NULL); |
7efcb746 | 2382 | for (n = case_list; n; n = n->right) |
28d81abb | 2383 | { |
28d81abb RK |
2384 | /* Count the elements and track the largest and smallest |
2385 | of them (treating them as signed even if they are not). */ | |
2386 | if (count++ == 0) | |
2387 | { | |
2388 | minval = n->low; | |
2389 | maxval = n->high; | |
2390 | } | |
2391 | else | |
2392 | { | |
2393 | if (INT_CST_LT (n->low, minval)) | |
2394 | minval = n->low; | |
2395 | if (INT_CST_LT (maxval, n->high)) | |
2396 | maxval = n->high; | |
2397 | } | |
2398 | /* A range counts double, since it requires two compares. */ | |
2399 | if (! tree_int_cst_equal (n->low, n->high)) | |
2400 | count++; | |
9bb231fd | 2401 | |
4cfa46c8 JL |
2402 | /* If we have not seen this label yet, then increase the |
2403 | number of unique case node targets seen. */ | |
9bb231fd | 2404 | lab = label_rtx (n->code_label); |
4cfa46c8 JL |
2405 | if (!bitmap_bit_p (label_bitmap, CODE_LABEL_NUMBER (lab))) |
2406 | { | |
2407 | bitmap_set_bit (label_bitmap, CODE_LABEL_NUMBER (lab)); | |
2408 | uniq++; | |
2409 | } | |
28d81abb RK |
2410 | } |
2411 | ||
8bdbfff5 | 2412 | BITMAP_FREE (label_bitmap); |
4cfa46c8 | 2413 | |
5372d088 | 2414 | /* cleanup_tree_cfg removes all SWITCH_EXPR with a single |
2aabee29 AO |
2415 | destination, such as one with a default case only. However, |
2416 | it doesn't remove cases that are out of range for the switch | |
2417 | type, so we may still get a zero here. */ | |
2418 | if (count == 0) | |
2419 | { | |
2420 | emit_jump (default_label); | |
2421 | return; | |
2422 | } | |
28d81abb | 2423 | |
5372d088 | 2424 | /* Compute span of values. */ |
4845b383 | 2425 | range = fold_build2 (MINUS_EXPR, index_type, maxval, minval); |
3474db0e | 2426 | |
9bb231fd RS |
2427 | /* Try implementing this switch statement by a short sequence of |
2428 | bit-wise comparisons. However, we let the binary-tree case | |
2429 | below handle constant index expressions. */ | |
5372d088 KH |
2430 | if (CASE_USE_BIT_TESTS |
2431 | && ! TREE_CONSTANT (index_expr) | |
2432 | && compare_tree_int (range, GET_MODE_BITSIZE (word_mode)) < 0 | |
2433 | && compare_tree_int (range, 0) > 0 | |
2434 | && lshift_cheap_p () | |
2435 | && ((uniq == 1 && count >= 3) | |
2436 | || (uniq == 2 && count >= 5) | |
2437 | || (uniq == 3 && count >= 6))) | |
9bb231fd RS |
2438 | { |
2439 | /* Optimize the case where all the case values fit in a | |
2440 | word without having to subtract MINVAL. In this case, | |
2441 | we can optimize away the subtraction. */ | |
2442 | if (compare_tree_int (minval, 0) > 0 | |
2443 | && compare_tree_int (maxval, GET_MODE_BITSIZE (word_mode)) < 0) | |
2444 | { | |
3bedcc89 | 2445 | minval = build_int_cst (index_type, 0); |
9bb231fd RS |
2446 | range = maxval; |
2447 | } | |
2448 | emit_case_bit_tests (index_type, index_expr, minval, range, | |
7efcb746 | 2449 | case_list, default_label); |
9bb231fd RS |
2450 | } |
2451 | ||
28d81abb RK |
2452 | /* If range of values is much bigger than number of values, |
2453 | make a sequence of conditional branches instead of a dispatch. | |
2454 | If the switch-index is a constant, do it this way | |
2455 | because we can optimize it. */ | |
4f73c5dd | 2456 | |
ad82abb8 | 2457 | else if (count < case_values_threshold () |
9e4b13a7 SB |
2458 | || compare_tree_int (range, |
2459 | (optimize_size ? 3 : 10) * count) > 0 | |
f0c988c8 BS |
2460 | /* RANGE may be signed, and really large ranges will show up |
2461 | as negative numbers. */ | |
2462 | || compare_tree_int (range, 0) < 0 | |
3f6fe18e RK |
2463 | #ifndef ASM_OUTPUT_ADDR_DIFF_ELT |
2464 | || flag_pic | |
2465 | #endif | |
82c0180d | 2466 | || !flag_jump_tables |
41cbdcd0 KH |
2467 | || TREE_CONSTANT (index_expr) |
2468 | /* If neither casesi or tablejump is available, we can | |
2469 | only go this way. */ | |
2470 | || (!HAVE_casesi && !HAVE_tablejump)) | |
28d81abb | 2471 | { |
84217346 | 2472 | index = expand_normal (index_expr); |
28d81abb RK |
2473 | |
2474 | /* If the index is a short or char that we do not have | |
2475 | an insn to handle comparisons directly, convert it to | |
2476 | a full integer now, rather than letting each comparison | |
2477 | generate the conversion. */ | |
2478 | ||
2479 | if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT | |
ef89d648 | 2480 | && ! have_insn_for (COMPARE, GET_MODE (index))) |
28d81abb RK |
2481 | { |
2482 | enum machine_mode wider_mode; | |
2483 | for (wider_mode = GET_MODE (index); wider_mode != VOIDmode; | |
2484 | wider_mode = GET_MODE_WIDER_MODE (wider_mode)) | |
ef89d648 | 2485 | if (have_insn_for (COMPARE, wider_mode)) |
28d81abb RK |
2486 | { |
2487 | index = convert_to_mode (wider_mode, index, unsignedp); | |
2488 | break; | |
2489 | } | |
2490 | } | |
2491 | ||
28d81abb RK |
2492 | do_pending_stack_adjust (); |
2493 | ||
3c0cb5de | 2494 | if (MEM_P (index)) |
28d81abb | 2495 | index = copy_to_reg (index); |
28d81abb | 2496 | |
b2c5a1e9 KH |
2497 | /* We generate a binary decision tree to select the |
2498 | appropriate target code. This is done as follows: | |
5100d114 KH |
2499 | |
2500 | The list of cases is rearranged into a binary tree, | |
2501 | nearly optimal assuming equal probability for each case. | |
2502 | ||
2503 | The tree is transformed into RTL, eliminating | |
2504 | redundant test conditions at the same time. | |
2505 | ||
2506 | If program flow could reach the end of the | |
2507 | decision tree an unconditional jump to the | |
2508 | default code is emitted. */ | |
2509 | ||
2510 | use_cost_table | |
2511 | = (TREE_CODE (orig_type) != ENUMERAL_TYPE | |
2512 | && estimate_case_costs (case_list)); | |
2513 | balance_case_nodes (&case_list, NULL); | |
2514 | emit_case_nodes (index, case_list, default_label, index_type); | |
2515 | emit_jump (default_label); | |
28d81abb RK |
2516 | } |
2517 | else | |
2518 | { | |
100e3acb | 2519 | table_label = gen_label_rtx (); |
ad82abb8 ZW |
2520 | if (! try_casesi (index_type, index_expr, minval, range, |
2521 | table_label, default_label)) | |
28d81abb | 2522 | { |
41374e13 | 2523 | bool ok; |
1ff37128 | 2524 | |
786de7eb | 2525 | /* Index jumptables from zero for suitable values of |
1ff37128 | 2526 | minval to avoid a subtraction. */ |
786de7eb KH |
2527 | if (! optimize_size |
2528 | && compare_tree_int (minval, 0) > 0 | |
2529 | && compare_tree_int (minval, 3) < 0) | |
2530 | { | |
3bedcc89 | 2531 | minval = build_int_cst (index_type, 0); |
786de7eb KH |
2532 | range = maxval; |
2533 | } | |
1ff37128 | 2534 | |
41374e13 NS |
2535 | ok = try_tablejump (index_type, index_expr, minval, range, |
2536 | table_label, default_label); | |
2537 | gcc_assert (ok); | |
28d81abb | 2538 | } |
786de7eb | 2539 | |
28d81abb RK |
2540 | /* Get table of labels to jump to, in order of case index. */ |
2541 | ||
1ff37128 | 2542 | ncases = tree_low_cst (range, 0) + 1; |
703ad42b KG |
2543 | labelvec = alloca (ncases * sizeof (rtx)); |
2544 | memset (labelvec, 0, ncases * sizeof (rtx)); | |
28d81abb | 2545 | |
7efcb746 | 2546 | for (n = case_list; n; n = n->right) |
28d81abb | 2547 | { |
2d9d49e4 OH |
2548 | /* Compute the low and high bounds relative to the minimum |
2549 | value since that should fit in a HOST_WIDE_INT while the | |
2550 | actual values may not. */ | |
2551 | HOST_WIDE_INT i_low | |
4845b383 KH |
2552 | = tree_low_cst (fold_build2 (MINUS_EXPR, index_type, |
2553 | n->low, minval), 1); | |
2d9d49e4 | 2554 | HOST_WIDE_INT i_high |
4845b383 KH |
2555 | = tree_low_cst (fold_build2 (MINUS_EXPR, index_type, |
2556 | n->high, minval), 1); | |
2d9d49e4 OH |
2557 | HOST_WIDE_INT i; |
2558 | ||
2559 | for (i = i_low; i <= i_high; i ++) | |
2560 | labelvec[i] | |
2561 | = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label)); | |
28d81abb RK |
2562 | } |
2563 | ||
2564 | /* Fill in the gaps with the default. */ | |
2565 | for (i = 0; i < ncases; i++) | |
2566 | if (labelvec[i] == 0) | |
38a448ca | 2567 | labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label); |
28d81abb | 2568 | |
f9da5064 | 2569 | /* Output the table. */ |
28d81abb RK |
2570 | emit_label (table_label); |
2571 | ||
18543a22 | 2572 | if (CASE_VECTOR_PC_RELATIVE || flag_pic) |
38a448ca RH |
2573 | emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE, |
2574 | gen_rtx_LABEL_REF (Pmode, table_label), | |
33f7f353 | 2575 | gen_rtvec_v (ncases, labelvec), |
4381f7c2 | 2576 | const0_rtx, const0_rtx)); |
28d81abb | 2577 | else |
38a448ca RH |
2578 | emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE, |
2579 | gen_rtvec_v (ncases, labelvec))); | |
28d81abb | 2580 | |
6be85b25 | 2581 | /* Record no drop-through after the table. */ |
28d81abb | 2582 | emit_barrier (); |
28d81abb RK |
2583 | } |
2584 | ||
2270623a JM |
2585 | before_case = NEXT_INSN (before_case); |
2586 | end = get_last_insn (); | |
7efcb746 | 2587 | reorder_insns (before_case, end, start); |
28d81abb | 2588 | } |
1b0cb6fc | 2589 | |
28d81abb RK |
2590 | free_temp_slots (); |
2591 | } | |
2592 | ||
feb04780 | 2593 | /* Generate code to jump to LABEL if OP0 and OP1 are equal in mode MODE. */ |
28d81abb RK |
2594 | |
2595 | static void | |
feb04780 RS |
2596 | do_jump_if_equal (enum machine_mode mode, rtx op0, rtx op1, rtx label, |
2597 | int unsignedp) | |
28d81abb | 2598 | { |
feb04780 RS |
2599 | do_compare_rtx_and_jump (op0, op1, EQ, unsignedp, mode, |
2600 | NULL_RTX, NULL_RTX, label); | |
28d81abb RK |
2601 | } |
2602 | \f | |
2603 | /* Not all case values are encountered equally. This function | |
2604 | uses a heuristic to weight case labels, in cases where that | |
2605 | looks like a reasonable thing to do. | |
2606 | ||
2607 | Right now, all we try to guess is text, and we establish the | |
2608 | following weights: | |
2609 | ||
2610 | chars above space: 16 | |
2611 | digits: 16 | |
2612 | default: 12 | |
2613 | space, punct: 8 | |
2614 | tab: 4 | |
2615 | newline: 2 | |
2616 | other "\" chars: 1 | |
2617 | remaining chars: 0 | |
2618 | ||
2619 | If we find any cases in the switch that are not either -1 or in the range | |
2620 | of valid ASCII characters, or are control characters other than those | |
2621 | commonly used with "\", don't treat this switch scanning text. | |
2622 | ||
2623 | Return 1 if these nodes are suitable for cost estimation, otherwise | |
2624 | return 0. */ | |
2625 | ||
2626 | static int | |
46c5ad27 | 2627 | estimate_case_costs (case_node_ptr node) |
28d81abb | 2628 | { |
f2d1f0ba | 2629 | tree min_ascii = integer_minus_one_node; |
aeba6c28 | 2630 | tree max_ascii = build_int_cst (TREE_TYPE (node->high), 127); |
28d81abb RK |
2631 | case_node_ptr n; |
2632 | int i; | |
2633 | ||
2634 | /* If we haven't already made the cost table, make it now. Note that the | |
2635 | lower bound of the table is -1, not zero. */ | |
2636 | ||
2a2137c4 | 2637 | if (! cost_table_initialized) |
28d81abb | 2638 | { |
2a2137c4 | 2639 | cost_table_initialized = 1; |
28d81abb RK |
2640 | |
2641 | for (i = 0; i < 128; i++) | |
2642 | { | |
e9a780ec | 2643 | if (ISALNUM (i)) |
2a2137c4 | 2644 | COST_TABLE (i) = 16; |
e9a780ec | 2645 | else if (ISPUNCT (i)) |
2a2137c4 | 2646 | COST_TABLE (i) = 8; |
e9a780ec | 2647 | else if (ISCNTRL (i)) |
2a2137c4 | 2648 | COST_TABLE (i) = -1; |
28d81abb RK |
2649 | } |
2650 | ||
2a2137c4 RH |
2651 | COST_TABLE (' ') = 8; |
2652 | COST_TABLE ('\t') = 4; | |
2653 | COST_TABLE ('\0') = 4; | |
2654 | COST_TABLE ('\n') = 2; | |
2655 | COST_TABLE ('\f') = 1; | |
2656 | COST_TABLE ('\v') = 1; | |
2657 | COST_TABLE ('\b') = 1; | |
28d81abb RK |
2658 | } |
2659 | ||
2660 | /* See if all the case expressions look like text. It is text if the | |
2661 | constant is >= -1 and the highest constant is <= 127. Do all comparisons | |
2662 | as signed arithmetic since we don't want to ever access cost_table with a | |
2663 | value less than -1. Also check that none of the constants in a range | |
2664 | are strange control characters. */ | |
2665 | ||
2666 | for (n = node; n; n = n->right) | |
2667 | { | |
2668 | if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high)) | |
2669 | return 0; | |
2670 | ||
05bccae2 RK |
2671 | for (i = (HOST_WIDE_INT) TREE_INT_CST_LOW (n->low); |
2672 | i <= (HOST_WIDE_INT) TREE_INT_CST_LOW (n->high); i++) | |
2a2137c4 | 2673 | if (COST_TABLE (i) < 0) |
28d81abb RK |
2674 | return 0; |
2675 | } | |
2676 | ||
2677 | /* All interesting values are within the range of interesting | |
2678 | ASCII characters. */ | |
2679 | return 1; | |
2680 | } | |
2681 | ||
28d81abb RK |
2682 | /* Take an ordered list of case nodes |
2683 | and transform them into a near optimal binary tree, | |
6dc42e49 | 2684 | on the assumption that any target code selection value is as |
28d81abb RK |
2685 | likely as any other. |
2686 | ||
2687 | The transformation is performed by splitting the ordered | |
2688 | list into two equal sections plus a pivot. The parts are | |
2689 | then attached to the pivot as left and right branches. Each | |
38e01259 | 2690 | branch is then transformed recursively. */ |
28d81abb RK |
2691 | |
2692 | static void | |
46c5ad27 | 2693 | balance_case_nodes (case_node_ptr *head, case_node_ptr parent) |
28d81abb | 2694 | { |
b3694847 | 2695 | case_node_ptr np; |
28d81abb RK |
2696 | |
2697 | np = *head; | |
2698 | if (np) | |
2699 | { | |
2700 | int cost = 0; | |
2701 | int i = 0; | |
2702 | int ranges = 0; | |
b3694847 | 2703 | case_node_ptr *npp; |
28d81abb RK |
2704 | case_node_ptr left; |
2705 | ||
2706 | /* Count the number of entries on branch. Also count the ranges. */ | |
2707 | ||
2708 | while (np) | |
2709 | { | |
2710 | if (!tree_int_cst_equal (np->low, np->high)) | |
2711 | { | |
2712 | ranges++; | |
2713 | if (use_cost_table) | |
2a2137c4 | 2714 | cost += COST_TABLE (TREE_INT_CST_LOW (np->high)); |
28d81abb RK |
2715 | } |
2716 | ||
2717 | if (use_cost_table) | |
2a2137c4 | 2718 | cost += COST_TABLE (TREE_INT_CST_LOW (np->low)); |
28d81abb RK |
2719 | |
2720 | i++; | |
2721 | np = np->right; | |
2722 | } | |
2723 | ||
2724 | if (i > 2) | |
2725 | { | |
2726 | /* Split this list if it is long enough for that to help. */ | |
2727 | npp = head; | |
2728 | left = *npp; | |
2729 | if (use_cost_table) | |
2730 | { | |
2731 | /* Find the place in the list that bisects the list's total cost, | |
2732 | Here I gets half the total cost. */ | |
2733 | int n_moved = 0; | |
2734 | i = (cost + 1) / 2; | |
2735 | while (1) | |
2736 | { | |
2737 | /* Skip nodes while their cost does not reach that amount. */ | |
2738 | if (!tree_int_cst_equal ((*npp)->low, (*npp)->high)) | |
2a2137c4 RH |
2739 | i -= COST_TABLE (TREE_INT_CST_LOW ((*npp)->high)); |
2740 | i -= COST_TABLE (TREE_INT_CST_LOW ((*npp)->low)); | |
28d81abb RK |
2741 | if (i <= 0) |
2742 | break; | |
2743 | npp = &(*npp)->right; | |
2744 | n_moved += 1; | |
2745 | } | |
2746 | if (n_moved == 0) | |
2747 | { | |
2748 | /* Leave this branch lopsided, but optimize left-hand | |
2749 | side and fill in `parent' fields for right-hand side. */ | |
2750 | np = *head; | |
2751 | np->parent = parent; | |
2752 | balance_case_nodes (&np->left, np); | |
2753 | for (; np->right; np = np->right) | |
2754 | np->right->parent = np; | |
2755 | return; | |
2756 | } | |
2757 | } | |
2758 | /* If there are just three nodes, split at the middle one. */ | |
2759 | else if (i == 3) | |
2760 | npp = &(*npp)->right; | |
2761 | else | |
2762 | { | |
2763 | /* Find the place in the list that bisects the list's total cost, | |
2764 | where ranges count as 2. | |
2765 | Here I gets half the total cost. */ | |
2766 | i = (i + ranges + 1) / 2; | |
2767 | while (1) | |
2768 | { | |
2769 | /* Skip nodes while their cost does not reach that amount. */ | |
2770 | if (!tree_int_cst_equal ((*npp)->low, (*npp)->high)) | |
2771 | i--; | |
2772 | i--; | |
2773 | if (i <= 0) | |
2774 | break; | |
2775 | npp = &(*npp)->right; | |
2776 | } | |
2777 | } | |
2778 | *head = np = *npp; | |
2779 | *npp = 0; | |
2780 | np->parent = parent; | |
2781 | np->left = left; | |
2782 | ||
2783 | /* Optimize each of the two split parts. */ | |
2784 | balance_case_nodes (&np->left, np); | |
2785 | balance_case_nodes (&np->right, np); | |
2786 | } | |
2787 | else | |
2788 | { | |
2789 | /* Else leave this branch as one level, | |
2790 | but fill in `parent' fields. */ | |
2791 | np = *head; | |
2792 | np->parent = parent; | |
2793 | for (; np->right; np = np->right) | |
2794 | np->right->parent = np; | |
2795 | } | |
2796 | } | |
2797 | } | |
2798 | \f | |
2799 | /* Search the parent sections of the case node tree | |
2800 | to see if a test for the lower bound of NODE would be redundant. | |
2801 | INDEX_TYPE is the type of the index expression. | |
2802 | ||
2803 | The instructions to generate the case decision tree are | |
2804 | output in the same order as nodes are processed so it is | |
2805 | known that if a parent node checks the range of the current | |
2806 | node minus one that the current node is bounded at its lower | |
2807 | span. Thus the test would be redundant. */ | |
2808 | ||
2809 | static int | |
46c5ad27 | 2810 | node_has_low_bound (case_node_ptr node, tree index_type) |
28d81abb RK |
2811 | { |
2812 | tree low_minus_one; | |
2813 | case_node_ptr pnode; | |
2814 | ||
2815 | /* If the lower bound of this node is the lowest value in the index type, | |
2816 | we need not test it. */ | |
2817 | ||
2818 | if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type))) | |
2819 | return 1; | |
2820 | ||
2821 | /* If this node has a left branch, the value at the left must be less | |
2822 | than that at this node, so it cannot be bounded at the bottom and | |
2823 | we need not bother testing any further. */ | |
2824 | ||
2825 | if (node->left) | |
2826 | return 0; | |
2827 | ||
4845b383 | 2828 | low_minus_one = fold_build2 (MINUS_EXPR, TREE_TYPE (node->low), |
3bedcc89 RG |
2829 | node->low, |
2830 | build_int_cst (TREE_TYPE (node->low), 1)); | |
28d81abb RK |
2831 | |
2832 | /* If the subtraction above overflowed, we can't verify anything. | |
2833 | Otherwise, look for a parent that tests our value - 1. */ | |
2834 | ||
2835 | if (! tree_int_cst_lt (low_minus_one, node->low)) | |
2836 | return 0; | |
2837 | ||
2838 | for (pnode = node->parent; pnode; pnode = pnode->parent) | |
2839 | if (tree_int_cst_equal (low_minus_one, pnode->high)) | |
2840 | return 1; | |
2841 | ||
2842 | return 0; | |
2843 | } | |
2844 | ||
2845 | /* Search the parent sections of the case node tree | |
2846 | to see if a test for the upper bound of NODE would be redundant. | |
2847 | INDEX_TYPE is the type of the index expression. | |
2848 | ||
2849 | The instructions to generate the case decision tree are | |
2850 | output in the same order as nodes are processed so it is | |
2851 | known that if a parent node checks the range of the current | |
2852 | node plus one that the current node is bounded at its upper | |
2853 | span. Thus the test would be redundant. */ | |
2854 | ||
2855 | static int | |
46c5ad27 | 2856 | node_has_high_bound (case_node_ptr node, tree index_type) |
28d81abb RK |
2857 | { |
2858 | tree high_plus_one; | |
2859 | case_node_ptr pnode; | |
2860 | ||
e1ee5cdc RH |
2861 | /* If there is no upper bound, obviously no test is needed. */ |
2862 | ||
2863 | if (TYPE_MAX_VALUE (index_type) == NULL) | |
2864 | return 1; | |
2865 | ||
28d81abb RK |
2866 | /* If the upper bound of this node is the highest value in the type |
2867 | of the index expression, we need not test against it. */ | |
2868 | ||
2869 | if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type))) | |
2870 | return 1; | |
2871 | ||
2872 | /* If this node has a right branch, the value at the right must be greater | |
2873 | than that at this node, so it cannot be bounded at the top and | |
2874 | we need not bother testing any further. */ | |
2875 | ||
2876 | if (node->right) | |
2877 | return 0; | |
2878 | ||
4845b383 | 2879 | high_plus_one = fold_build2 (PLUS_EXPR, TREE_TYPE (node->high), |
3bedcc89 RG |
2880 | node->high, |
2881 | build_int_cst (TREE_TYPE (node->high), 1)); | |
28d81abb RK |
2882 | |
2883 | /* If the addition above overflowed, we can't verify anything. | |
2884 | Otherwise, look for a parent that tests our value + 1. */ | |
2885 | ||
2886 | if (! tree_int_cst_lt (node->high, high_plus_one)) | |
2887 | return 0; | |
2888 | ||
2889 | for (pnode = node->parent; pnode; pnode = pnode->parent) | |
2890 | if (tree_int_cst_equal (high_plus_one, pnode->low)) | |
2891 | return 1; | |
2892 | ||
2893 | return 0; | |
2894 | } | |
2895 | ||
2896 | /* Search the parent sections of the | |
2897 | case node tree to see if both tests for the upper and lower | |
2898 | bounds of NODE would be redundant. */ | |
2899 | ||
2900 | static int | |
46c5ad27 | 2901 | node_is_bounded (case_node_ptr node, tree index_type) |
28d81abb RK |
2902 | { |
2903 | return (node_has_low_bound (node, index_type) | |
2904 | && node_has_high_bound (node, index_type)); | |
2905 | } | |
28d81abb RK |
2906 | \f |
2907 | /* Emit step-by-step code to select a case for the value of INDEX. | |
2908 | The thus generated decision tree follows the form of the | |
2909 | case-node binary tree NODE, whose nodes represent test conditions. | |
2910 | INDEX_TYPE is the type of the index of the switch. | |
2911 | ||
2912 | Care is taken to prune redundant tests from the decision tree | |
2913 | by detecting any boundary conditions already checked by | |
2914 | emitted rtx. (See node_has_high_bound, node_has_low_bound | |
2915 | and node_is_bounded, above.) | |
2916 | ||
2917 | Where the test conditions can be shown to be redundant we emit | |
2918 | an unconditional jump to the target code. As a further | |
2919 | optimization, the subordinates of a tree node are examined to | |
2920 | check for bounded nodes. In this case conditional and/or | |
2921 | unconditional jumps as a result of the boundary check for the | |
2922 | current node are arranged to target the subordinates associated | |
38e01259 | 2923 | code for out of bound conditions on the current node. |
28d81abb | 2924 | |
f72aed24 | 2925 | We can assume that when control reaches the code generated here, |
28d81abb RK |
2926 | the index value has already been compared with the parents |
2927 | of this node, and determined to be on the same side of each parent | |
2928 | as this node is. Thus, if this node tests for the value 51, | |
2929 | and a parent tested for 52, we don't need to consider | |
2930 | the possibility of a value greater than 51. If another parent | |
2931 | tests for the value 50, then this node need not test anything. */ | |
2932 | ||
2933 | static void | |
46c5ad27 AJ |
2934 | emit_case_nodes (rtx index, case_node_ptr node, rtx default_label, |
2935 | tree index_type) | |
28d81abb RK |
2936 | { |
2937 | /* If INDEX has an unsigned type, we must make unsigned branches. */ | |
8df83eae | 2938 | int unsignedp = TYPE_UNSIGNED (index_type); |
28d81abb | 2939 | enum machine_mode mode = GET_MODE (index); |
69107307 | 2940 | enum machine_mode imode = TYPE_MODE (index_type); |
28d81abb | 2941 | |
f8318079 RS |
2942 | /* Handle indices detected as constant during RTL expansion. */ |
2943 | if (mode == VOIDmode) | |
2944 | mode = imode; | |
2945 | ||
28d81abb RK |
2946 | /* See if our parents have already tested everything for us. |
2947 | If they have, emit an unconditional jump for this node. */ | |
2948 | if (node_is_bounded (node, index_type)) | |
2949 | emit_jump (label_rtx (node->code_label)); | |
2950 | ||
2951 | else if (tree_int_cst_equal (node->low, node->high)) | |
2952 | { | |
2953 | /* Node is single valued. First see if the index expression matches | |
0f41302f | 2954 | this node and then check our children, if any. */ |
28d81abb | 2955 | |
feb04780 | 2956 | do_jump_if_equal (mode, index, |
69107307 | 2957 | convert_modes (mode, imode, |
84217346 | 2958 | expand_normal (node->low), |
69107307 | 2959 | unsignedp), |
28d81abb RK |
2960 | label_rtx (node->code_label), unsignedp); |
2961 | ||
2962 | if (node->right != 0 && node->left != 0) | |
2963 | { | |
2964 | /* This node has children on both sides. | |
2965 | Dispatch to one side or the other | |
2966 | by comparing the index value with this node's value. | |
2967 | If one subtree is bounded, check that one first, | |
2968 | so we can avoid real branches in the tree. */ | |
2969 | ||
2970 | if (node_is_bounded (node->right, index_type)) | |
2971 | { | |
4381f7c2 | 2972 | emit_cmp_and_jump_insns (index, |
69107307 AO |
2973 | convert_modes |
2974 | (mode, imode, | |
84217346 | 2975 | expand_normal (node->high), |
69107307 | 2976 | unsignedp), |
d43e0b7d | 2977 | GT, NULL_RTX, mode, unsignedp, |
4381f7c2 | 2978 | label_rtx (node->right->code_label)); |
28d81abb RK |
2979 | emit_case_nodes (index, node->left, default_label, index_type); |
2980 | } | |
2981 | ||
2982 | else if (node_is_bounded (node->left, index_type)) | |
2983 | { | |
4381f7c2 | 2984 | emit_cmp_and_jump_insns (index, |
69107307 AO |
2985 | convert_modes |
2986 | (mode, imode, | |
84217346 | 2987 | expand_normal (node->high), |
69107307 | 2988 | unsignedp), |
d43e0b7d | 2989 | LT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 2990 | label_rtx (node->left->code_label)); |
28d81abb RK |
2991 | emit_case_nodes (index, node->right, default_label, index_type); |
2992 | } | |
2993 | ||
43a21dfc KH |
2994 | /* If both children are single-valued cases with no |
2995 | children, finish up all the work. This way, we can save | |
2996 | one ordered comparison. */ | |
2997 | else if (tree_int_cst_equal (node->right->low, node->right->high) | |
2998 | && node->right->left == 0 | |
2999 | && node->right->right == 0 | |
3000 | && tree_int_cst_equal (node->left->low, node->left->high) | |
3001 | && node->left->left == 0 | |
3002 | && node->left->right == 0) | |
3003 | { | |
3004 | /* Neither node is bounded. First distinguish the two sides; | |
3005 | then emit the code for one side at a time. */ | |
3006 | ||
3007 | /* See if the value matches what the right hand side | |
3008 | wants. */ | |
feb04780 | 3009 | do_jump_if_equal (mode, index, |
43a21dfc | 3010 | convert_modes (mode, imode, |
84217346 | 3011 | expand_normal (node->right->low), |
43a21dfc KH |
3012 | unsignedp), |
3013 | label_rtx (node->right->code_label), | |
3014 | unsignedp); | |
3015 | ||
3016 | /* See if the value matches what the left hand side | |
3017 | wants. */ | |
feb04780 | 3018 | do_jump_if_equal (mode, index, |
43a21dfc | 3019 | convert_modes (mode, imode, |
84217346 | 3020 | expand_normal (node->left->low), |
43a21dfc KH |
3021 | unsignedp), |
3022 | label_rtx (node->left->code_label), | |
3023 | unsignedp); | |
3024 | } | |
3025 | ||
28d81abb RK |
3026 | else |
3027 | { | |
3028 | /* Neither node is bounded. First distinguish the two sides; | |
3029 | then emit the code for one side at a time. */ | |
3030 | ||
4381f7c2 | 3031 | tree test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE); |
28d81abb RK |
3032 | |
3033 | /* See if the value is on the right. */ | |
4381f7c2 | 3034 | emit_cmp_and_jump_insns (index, |
69107307 AO |
3035 | convert_modes |
3036 | (mode, imode, | |
84217346 | 3037 | expand_normal (node->high), |
69107307 | 3038 | unsignedp), |
d43e0b7d | 3039 | GT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3040 | label_rtx (test_label)); |
28d81abb RK |
3041 | |
3042 | /* Value must be on the left. | |
3043 | Handle the left-hand subtree. */ | |
3044 | emit_case_nodes (index, node->left, default_label, index_type); | |
3045 | /* If left-hand subtree does nothing, | |
3046 | go to default. */ | |
165b54c3 | 3047 | emit_jump (default_label); |
28d81abb RK |
3048 | |
3049 | /* Code branches here for the right-hand subtree. */ | |
3050 | expand_label (test_label); | |
3051 | emit_case_nodes (index, node->right, default_label, index_type); | |
3052 | } | |
3053 | } | |
3054 | ||
3055 | else if (node->right != 0 && node->left == 0) | |
3056 | { | |
adb35797 | 3057 | /* Here we have a right child but no left so we issue a conditional |
28d81abb RK |
3058 | branch to default and process the right child. |
3059 | ||
adb35797 KH |
3060 | Omit the conditional branch to default if the right child |
3061 | does not have any children and is single valued; it would | |
3062 | cost too much space to save so little time. */ | |
28d81abb | 3063 | |
de14fd73 | 3064 | if (node->right->right || node->right->left |
28d81abb RK |
3065 | || !tree_int_cst_equal (node->right->low, node->right->high)) |
3066 | { | |
3067 | if (!node_has_low_bound (node, index_type)) | |
3068 | { | |
4381f7c2 | 3069 | emit_cmp_and_jump_insns (index, |
69107307 AO |
3070 | convert_modes |
3071 | (mode, imode, | |
84217346 | 3072 | expand_normal (node->high), |
69107307 | 3073 | unsignedp), |
d43e0b7d | 3074 | LT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3075 | default_label); |
28d81abb RK |
3076 | } |
3077 | ||
3078 | emit_case_nodes (index, node->right, default_label, index_type); | |
3079 | } | |
3080 | else | |
3081 | /* We cannot process node->right normally | |
3082 | since we haven't ruled out the numbers less than | |
3083 | this node's value. So handle node->right explicitly. */ | |
feb04780 | 3084 | do_jump_if_equal (mode, index, |
69107307 AO |
3085 | convert_modes |
3086 | (mode, imode, | |
84217346 | 3087 | expand_normal (node->right->low), |
69107307 | 3088 | unsignedp), |
28d81abb RK |
3089 | label_rtx (node->right->code_label), unsignedp); |
3090 | } | |
3091 | ||
3092 | else if (node->right == 0 && node->left != 0) | |
3093 | { | |
3094 | /* Just one subtree, on the left. */ | |
4381f7c2 | 3095 | if (node->left->left || node->left->right |
28d81abb RK |
3096 | || !tree_int_cst_equal (node->left->low, node->left->high)) |
3097 | { | |
3098 | if (!node_has_high_bound (node, index_type)) | |
3099 | { | |
69107307 AO |
3100 | emit_cmp_and_jump_insns (index, |
3101 | convert_modes | |
3102 | (mode, imode, | |
84217346 | 3103 | expand_normal (node->high), |
69107307 | 3104 | unsignedp), |
d43e0b7d | 3105 | GT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3106 | default_label); |
28d81abb RK |
3107 | } |
3108 | ||
3109 | emit_case_nodes (index, node->left, default_label, index_type); | |
3110 | } | |
3111 | else | |
3112 | /* We cannot process node->left normally | |
3113 | since we haven't ruled out the numbers less than | |
3114 | this node's value. So handle node->left explicitly. */ | |
feb04780 | 3115 | do_jump_if_equal (mode, index, |
69107307 AO |
3116 | convert_modes |
3117 | (mode, imode, | |
84217346 | 3118 | expand_normal (node->left->low), |
69107307 | 3119 | unsignedp), |
28d81abb RK |
3120 | label_rtx (node->left->code_label), unsignedp); |
3121 | } | |
3122 | } | |
3123 | else | |
3124 | { | |
3125 | /* Node is a range. These cases are very similar to those for a single | |
3126 | value, except that we do not start by testing whether this node | |
3127 | is the one to branch to. */ | |
3128 | ||
3129 | if (node->right != 0 && node->left != 0) | |
3130 | { | |
3131 | /* Node has subtrees on both sides. | |
3132 | If the right-hand subtree is bounded, | |
3133 | test for it first, since we can go straight there. | |
3134 | Otherwise, we need to make a branch in the control structure, | |
3135 | then handle the two subtrees. */ | |
3136 | tree test_label = 0; | |
3137 | ||
28d81abb RK |
3138 | if (node_is_bounded (node->right, index_type)) |
3139 | /* Right hand node is fully bounded so we can eliminate any | |
3140 | testing and branch directly to the target code. */ | |
69107307 AO |
3141 | emit_cmp_and_jump_insns (index, |
3142 | convert_modes | |
3143 | (mode, imode, | |
84217346 | 3144 | expand_normal (node->high), |
69107307 | 3145 | unsignedp), |
d43e0b7d | 3146 | GT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3147 | label_rtx (node->right->code_label)); |
28d81abb RK |
3148 | else |
3149 | { | |
3150 | /* Right hand node requires testing. | |
3151 | Branch to a label where we will handle it later. */ | |
3152 | ||
3153 | test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE); | |
4381f7c2 | 3154 | emit_cmp_and_jump_insns (index, |
69107307 AO |
3155 | convert_modes |
3156 | (mode, imode, | |
84217346 | 3157 | expand_normal (node->high), |
69107307 | 3158 | unsignedp), |
d43e0b7d | 3159 | GT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3160 | label_rtx (test_label)); |
28d81abb RK |
3161 | } |
3162 | ||
3163 | /* Value belongs to this node or to the left-hand subtree. */ | |
3164 | ||
69107307 AO |
3165 | emit_cmp_and_jump_insns (index, |
3166 | convert_modes | |
3167 | (mode, imode, | |
84217346 | 3168 | expand_normal (node->low), |
69107307 | 3169 | unsignedp), |
d43e0b7d | 3170 | GE, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3171 | label_rtx (node->code_label)); |
28d81abb RK |
3172 | |
3173 | /* Handle the left-hand subtree. */ | |
3174 | emit_case_nodes (index, node->left, default_label, index_type); | |
3175 | ||
3176 | /* If right node had to be handled later, do that now. */ | |
3177 | ||
3178 | if (test_label) | |
3179 | { | |
3180 | /* If the left-hand subtree fell through, | |
3181 | don't let it fall into the right-hand subtree. */ | |
165b54c3 | 3182 | emit_jump (default_label); |
28d81abb RK |
3183 | |
3184 | expand_label (test_label); | |
3185 | emit_case_nodes (index, node->right, default_label, index_type); | |
3186 | } | |
3187 | } | |
3188 | ||
3189 | else if (node->right != 0 && node->left == 0) | |
3190 | { | |
3191 | /* Deal with values to the left of this node, | |
3192 | if they are possible. */ | |
3193 | if (!node_has_low_bound (node, index_type)) | |
3194 | { | |
4381f7c2 | 3195 | emit_cmp_and_jump_insns (index, |
69107307 AO |
3196 | convert_modes |
3197 | (mode, imode, | |
84217346 | 3198 | expand_normal (node->low), |
69107307 | 3199 | unsignedp), |
d43e0b7d | 3200 | LT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3201 | default_label); |
28d81abb RK |
3202 | } |
3203 | ||
3204 | /* Value belongs to this node or to the right-hand subtree. */ | |
3205 | ||
69107307 AO |
3206 | emit_cmp_and_jump_insns (index, |
3207 | convert_modes | |
3208 | (mode, imode, | |
84217346 | 3209 | expand_normal (node->high), |
69107307 | 3210 | unsignedp), |
d43e0b7d | 3211 | LE, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3212 | label_rtx (node->code_label)); |
28d81abb RK |
3213 | |
3214 | emit_case_nodes (index, node->right, default_label, index_type); | |
3215 | } | |
3216 | ||
3217 | else if (node->right == 0 && node->left != 0) | |
3218 | { | |
3219 | /* Deal with values to the right of this node, | |
3220 | if they are possible. */ | |
3221 | if (!node_has_high_bound (node, index_type)) | |
3222 | { | |
4381f7c2 | 3223 | emit_cmp_and_jump_insns (index, |
69107307 AO |
3224 | convert_modes |
3225 | (mode, imode, | |
84217346 | 3226 | expand_normal (node->high), |
69107307 | 3227 | unsignedp), |
d43e0b7d | 3228 | GT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3229 | default_label); |
28d81abb RK |
3230 | } |
3231 | ||
3232 | /* Value belongs to this node or to the left-hand subtree. */ | |
3233 | ||
4381f7c2 | 3234 | emit_cmp_and_jump_insns (index, |
69107307 AO |
3235 | convert_modes |
3236 | (mode, imode, | |
84217346 | 3237 | expand_normal (node->low), |
69107307 | 3238 | unsignedp), |
d43e0b7d | 3239 | GE, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3240 | label_rtx (node->code_label)); |
28d81abb RK |
3241 | |
3242 | emit_case_nodes (index, node->left, default_label, index_type); | |
3243 | } | |
3244 | ||
3245 | else | |
3246 | { | |
3247 | /* Node has no children so we check low and high bounds to remove | |
3248 | redundant tests. Only one of the bounds can exist, | |
3249 | since otherwise this node is bounded--a case tested already. */ | |
923cbdc3 JH |
3250 | int high_bound = node_has_high_bound (node, index_type); |
3251 | int low_bound = node_has_low_bound (node, index_type); | |
28d81abb | 3252 | |
923cbdc3 | 3253 | if (!high_bound && low_bound) |
28d81abb | 3254 | { |
4381f7c2 | 3255 | emit_cmp_and_jump_insns (index, |
69107307 AO |
3256 | convert_modes |
3257 | (mode, imode, | |
84217346 | 3258 | expand_normal (node->high), |
69107307 | 3259 | unsignedp), |
d43e0b7d | 3260 | GT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3261 | default_label); |
28d81abb RK |
3262 | } |
3263 | ||
923cbdc3 | 3264 | else if (!low_bound && high_bound) |
28d81abb | 3265 | { |
4381f7c2 | 3266 | emit_cmp_and_jump_insns (index, |
69107307 AO |
3267 | convert_modes |
3268 | (mode, imode, | |
84217346 | 3269 | expand_normal (node->low), |
69107307 | 3270 | unsignedp), |
d43e0b7d | 3271 | LT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3272 | default_label); |
28d81abb | 3273 | } |
923cbdc3 JH |
3274 | else if (!low_bound && !high_bound) |
3275 | { | |
9312aecc | 3276 | /* Widen LOW and HIGH to the same width as INDEX. */ |
ae2bcd98 | 3277 | tree type = lang_hooks.types.type_for_mode (mode, unsignedp); |
9312aecc JDA |
3278 | tree low = build1 (CONVERT_EXPR, type, node->low); |
3279 | tree high = build1 (CONVERT_EXPR, type, node->high); | |
ef89d648 | 3280 | rtx low_rtx, new_index, new_bound; |
9312aecc JDA |
3281 | |
3282 | /* Instead of doing two branches, emit one unsigned branch for | |
3283 | (index-low) > (high-low). */ | |
84217346 | 3284 | low_rtx = expand_expr (low, NULL_RTX, mode, EXPAND_NORMAL); |
ef89d648 ZW |
3285 | new_index = expand_simple_binop (mode, MINUS, index, low_rtx, |
3286 | NULL_RTX, unsignedp, | |
3287 | OPTAB_WIDEN); | |
4845b383 KH |
3288 | new_bound = expand_expr (fold_build2 (MINUS_EXPR, type, |
3289 | high, low), | |
84217346 | 3290 | NULL_RTX, mode, EXPAND_NORMAL); |
786de7eb | 3291 | |
9312aecc | 3292 | emit_cmp_and_jump_insns (new_index, new_bound, GT, NULL_RTX, |
d43e0b7d | 3293 | mode, 1, default_label); |
923cbdc3 | 3294 | } |
28d81abb RK |
3295 | |
3296 | emit_jump (label_rtx (node->code_label)); | |
3297 | } | |
3298 | } | |
3299 | } |