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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, |
eca72963 | 3 | 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 |
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" |
6ac1b3a4 | 52 | #include "alloc-pool.h" |
28d81abb RK |
53 | \f |
54 | /* Functions and data structures for expanding case statements. */ | |
55 | ||
56 | /* Case label structure, used to hold info on labels within case | |
57 | statements. We handle "range" labels; for a single-value label | |
58 | as in C, the high and low limits are the same. | |
59 | ||
a6c0a76c SB |
60 | We start with a vector of case nodes sorted in ascending order, and |
61 | the default label as the last element in the vector. Before expanding | |
62 | to RTL, we transform this vector into a list linked via the RIGHT | |
63 | fields in the case_node struct. Nodes with higher case values are | |
64 | later in the list. | |
65 | ||
66 | Switch statements can be output in three forms. A branch table is | |
67 | used if there are more than a few labels and the labels are dense | |
28d81abb RK |
68 | within the range between the smallest and largest case value. If a |
69 | branch table is used, no further manipulations are done with the case | |
70 | node chain. | |
71 | ||
72 | The alternative to the use of a branch table is to generate a series | |
73 | of compare and jump insns. When that is done, we use the LEFT, RIGHT, | |
74 | and PARENT fields to hold a binary tree. Initially the tree is | |
de14fd73 RK |
75 | totally unbalanced, with everything on the right. We balance the tree |
76 | with nodes on the left having lower case values than the parent | |
28d81abb | 77 | and nodes on the right having higher values. We then output the tree |
a6c0a76c SB |
78 | in order. |
79 | ||
80 | For very small, suitable switch statements, we can generate a series | |
81 | of simple bit test and branches instead. */ | |
28d81abb | 82 | |
6ac1b3a4 | 83 | struct case_node |
28d81abb RK |
84 | { |
85 | struct case_node *left; /* Left son in binary tree */ | |
86 | struct case_node *right; /* Right son in binary tree; also node chain */ | |
87 | struct case_node *parent; /* Parent of node in binary tree */ | |
88 | tree low; /* Lowest index value for this label */ | |
89 | tree high; /* Highest index value for this label */ | |
90 | tree code_label; /* Label to jump to when node matches */ | |
91 | }; | |
92 | ||
93 | typedef struct case_node case_node; | |
94 | typedef struct case_node *case_node_ptr; | |
95 | ||
96 | /* These are used by estimate_case_costs and balance_case_nodes. */ | |
97 | ||
98 | /* This must be a signed type, and non-ANSI compilers lack signed char. */ | |
e7749837 | 99 | static short cost_table_[129]; |
28d81abb | 100 | static int use_cost_table; |
2a2137c4 RH |
101 | static int cost_table_initialized; |
102 | ||
103 | /* Special care is needed because we allow -1, but TREE_INT_CST_LOW | |
104 | is unsigned. */ | |
cf403648 | 105 | #define COST_TABLE(I) cost_table_[(unsigned HOST_WIDE_INT) ((I) + 1)] |
28d81abb | 106 | \f |
46c5ad27 | 107 | static int n_occurrences (int, const char *); |
91b4415a | 108 | static bool tree_conflicts_with_clobbers_p (tree, HARD_REG_SET *); |
46c5ad27 | 109 | static void expand_nl_goto_receiver (void); |
46c5ad27 AJ |
110 | static bool check_operand_nalternatives (tree, tree); |
111 | static bool check_unique_operand_names (tree, tree); | |
112 | static char *resolve_operand_name_1 (char *, tree, tree); | |
ac45df5d | 113 | static void expand_null_return_1 (void); |
46c5ad27 | 114 | static void expand_value_return (rtx); |
46c5ad27 | 115 | static int estimate_case_costs (case_node_ptr); |
46c5ad27 AJ |
116 | static bool lshift_cheap_p (void); |
117 | static int case_bit_test_cmp (const void *, const void *); | |
118 | static void emit_case_bit_tests (tree, tree, tree, tree, case_node_ptr, rtx); | |
46c5ad27 AJ |
119 | static void balance_case_nodes (case_node_ptr *, case_node_ptr); |
120 | static int node_has_low_bound (case_node_ptr, tree); | |
121 | static int node_has_high_bound (case_node_ptr, tree); | |
122 | static int node_is_bounded (case_node_ptr, tree); | |
46c5ad27 | 123 | static void emit_case_nodes (rtx, case_node_ptr, rtx, tree); |
eb172681 | 124 | static struct case_node *add_case_node (struct case_node *, tree, |
6ac1b3a4 | 125 | tree, tree, tree, alloc_pool); |
0cea056b | 126 | |
28d81abb RK |
127 | \f |
128 | /* Return the rtx-label that corresponds to a LABEL_DECL, | |
129 | creating it if necessary. */ | |
130 | ||
131 | rtx | |
46c5ad27 | 132 | label_rtx (tree label) |
28d81abb | 133 | { |
41374e13 | 134 | gcc_assert (TREE_CODE (label) == LABEL_DECL); |
28d81abb | 135 | |
19e7881c | 136 | if (!DECL_RTL_SET_P (label)) |
6de9cd9a DN |
137 | { |
138 | rtx r = gen_label_rtx (); | |
139 | SET_DECL_RTL (label, r); | |
140 | if (FORCED_LABEL (label) || DECL_NONLOCAL (label)) | |
141 | LABEL_PRESERVE_P (r) = 1; | |
142 | } | |
28d81abb | 143 | |
19e7881c | 144 | return DECL_RTL (label); |
28d81abb RK |
145 | } |
146 | ||
046e4e36 ZW |
147 | /* As above, but also put it on the forced-reference list of the |
148 | function that contains it. */ | |
149 | rtx | |
46c5ad27 | 150 | force_label_rtx (tree label) |
046e4e36 ZW |
151 | { |
152 | rtx ref = label_rtx (label); | |
153 | tree function = decl_function_context (label); | |
046e4e36 | 154 | |
41374e13 | 155 | gcc_assert (function); |
046e4e36 | 156 | |
bd60bab2 | 157 | forced_labels = gen_rtx_EXPR_LIST (VOIDmode, ref, forced_labels); |
046e4e36 ZW |
158 | return ref; |
159 | } | |
19e7881c | 160 | |
28d81abb RK |
161 | /* Add an unconditional jump to LABEL as the next sequential instruction. */ |
162 | ||
163 | void | |
46c5ad27 | 164 | emit_jump (rtx label) |
28d81abb RK |
165 | { |
166 | do_pending_stack_adjust (); | |
167 | emit_jump_insn (gen_jump (label)); | |
168 | emit_barrier (); | |
169 | } | |
170 | ||
171 | /* Emit code to jump to the address | |
172 | specified by the pointer expression EXP. */ | |
173 | ||
174 | void | |
46c5ad27 | 175 | expand_computed_goto (tree exp) |
28d81abb | 176 | { |
84217346 | 177 | rtx x = expand_normal (exp); |
ed9a9db1 | 178 | |
5ae6cd0d | 179 | x = convert_memory_address (Pmode, x); |
ffa1a1ce | 180 | |
eb4e1c01 JH |
181 | do_pending_stack_adjust (); |
182 | emit_indirect_jump (x); | |
28d81abb RK |
183 | } |
184 | \f | |
185 | /* Handle goto statements and the labels that they can go to. */ | |
186 | ||
187 | /* Specify the location in the RTL code of a label LABEL, | |
188 | which is a LABEL_DECL tree node. | |
189 | ||
190 | This is used for the kind of label that the user can jump to with a | |
191 | goto statement, and for alternatives of a switch or case statement. | |
192 | RTL labels generated for loops and conditionals don't go through here; | |
193 | they are generated directly at the RTL level, by other functions below. | |
194 | ||
195 | Note that this has nothing to do with defining label *names*. | |
196 | Languages vary in how they do that and what that even means. */ | |
197 | ||
198 | void | |
46c5ad27 | 199 | expand_label (tree label) |
28d81abb | 200 | { |
6de9cd9a | 201 | rtx label_r = label_rtx (label); |
28d81abb RK |
202 | |
203 | do_pending_stack_adjust (); | |
6de9cd9a | 204 | emit_label (label_r); |
28d81abb RK |
205 | if (DECL_NAME (label)) |
206 | LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label)); | |
207 | ||
6de9cd9a DN |
208 | if (DECL_NONLOCAL (label)) |
209 | { | |
210 | expand_nl_goto_receiver (); | |
211 | nonlocal_goto_handler_labels | |
212 | = gen_rtx_EXPR_LIST (VOIDmode, label_r, | |
213 | nonlocal_goto_handler_labels); | |
214 | } | |
215 | ||
216 | if (FORCED_LABEL (label)) | |
217 | forced_labels = gen_rtx_EXPR_LIST (VOIDmode, label_r, forced_labels); | |
caf93cb0 | 218 | |
6de9cd9a DN |
219 | if (DECL_NONLOCAL (label) || FORCED_LABEL (label)) |
220 | maybe_set_first_label_num (label_r); | |
28d81abb RK |
221 | } |
222 | ||
28d81abb RK |
223 | /* Generate RTL code for a `goto' statement with target label LABEL. |
224 | LABEL should be a LABEL_DECL tree node that was or will later be | |
225 | defined with `expand_label'. */ | |
226 | ||
227 | void | |
46c5ad27 | 228 | expand_goto (tree label) |
28d81abb | 229 | { |
6de9cd9a DN |
230 | #ifdef ENABLE_CHECKING |
231 | /* Check for a nonlocal goto to a containing function. Should have | |
232 | gotten translated to __builtin_nonlocal_goto. */ | |
233 | tree context = decl_function_context (label); | |
41374e13 | 234 | gcc_assert (!context || context == current_function_decl); |
28d81abb | 235 | #endif |
4b01bd16 | 236 | |
ac45df5d | 237 | emit_jump (label_rtx (label)); |
28d81abb | 238 | } |
2a230e9d BS |
239 | \f |
240 | /* Return the number of times character C occurs in string S. */ | |
241 | static int | |
46c5ad27 | 242 | n_occurrences (int c, const char *s) |
2a230e9d BS |
243 | { |
244 | int n = 0; | |
245 | while (*s) | |
246 | n += (*s++ == c); | |
247 | return n; | |
248 | } | |
28d81abb RK |
249 | \f |
250 | /* Generate RTL for an asm statement (explicit assembler code). | |
4c46ea23 EB |
251 | STRING is a STRING_CST node containing the assembler code text, |
252 | or an ADDR_EXPR containing a STRING_CST. VOL nonzero means the | |
253 | insn is volatile; don't optimize it. */ | |
28d81abb | 254 | |
bac6bfc5 | 255 | static void |
bff4b63d | 256 | expand_asm_loc (tree string, int vol, location_t locus) |
28d81abb | 257 | { |
4c46ea23 EB |
258 | rtx body; |
259 | ||
260 | if (TREE_CODE (string) == ADDR_EXPR) | |
261 | string = TREE_OPERAND (string, 0); | |
262 | ||
bff4b63d AO |
263 | body = gen_rtx_ASM_INPUT_loc (VOIDmode, |
264 | ggc_strdup (TREE_STRING_POINTER (string)), | |
265 | locus); | |
4c46ea23 EB |
266 | |
267 | MEM_VOLATILE_P (body) = vol; | |
28d81abb | 268 | |
4c46ea23 | 269 | emit_insn (body); |
28d81abb RK |
270 | } |
271 | ||
40b18c0a MM |
272 | /* Parse the output constraint pointed to by *CONSTRAINT_P. It is the |
273 | OPERAND_NUMth output operand, indexed from zero. There are NINPUTS | |
274 | inputs and NOUTPUTS outputs to this extended-asm. Upon return, | |
275 | *ALLOWS_MEM will be TRUE iff the constraint allows the use of a | |
276 | memory operand. Similarly, *ALLOWS_REG will be TRUE iff the | |
277 | constraint allows the use of a register operand. And, *IS_INOUT | |
278 | will be true if the operand is read-write, i.e., if it is used as | |
279 | an input as well as an output. If *CONSTRAINT_P is not in | |
280 | canonical form, it will be made canonical. (Note that `+' will be | |
14b493d6 | 281 | replaced with `=' as part of this process.) |
40b18c0a MM |
282 | |
283 | Returns TRUE if all went well; FALSE if an error occurred. */ | |
284 | ||
285 | bool | |
46c5ad27 AJ |
286 | parse_output_constraint (const char **constraint_p, int operand_num, |
287 | int ninputs, int noutputs, bool *allows_mem, | |
288 | bool *allows_reg, bool *is_inout) | |
40b18c0a MM |
289 | { |
290 | const char *constraint = *constraint_p; | |
291 | const char *p; | |
292 | ||
293 | /* Assume the constraint doesn't allow the use of either a register | |
294 | or memory. */ | |
295 | *allows_mem = false; | |
296 | *allows_reg = false; | |
297 | ||
298 | /* Allow the `=' or `+' to not be at the beginning of the string, | |
299 | since it wasn't explicitly documented that way, and there is a | |
300 | large body of code that puts it last. Swap the character to | |
301 | the front, so as not to uglify any place else. */ | |
302 | p = strchr (constraint, '='); | |
303 | if (!p) | |
304 | p = strchr (constraint, '+'); | |
305 | ||
306 | /* If the string doesn't contain an `=', issue an error | |
307 | message. */ | |
308 | if (!p) | |
309 | { | |
971801ff | 310 | error ("output operand constraint lacks %<=%>"); |
40b18c0a MM |
311 | return false; |
312 | } | |
313 | ||
314 | /* If the constraint begins with `+', then the operand is both read | |
315 | from and written to. */ | |
316 | *is_inout = (*p == '+'); | |
317 | ||
40b18c0a | 318 | /* Canonicalize the output constraint so that it begins with `='. */ |
372d72d9 | 319 | if (p != constraint || *is_inout) |
40b18c0a MM |
320 | { |
321 | char *buf; | |
322 | size_t c_len = strlen (constraint); | |
323 | ||
324 | if (p != constraint) | |
d4ee4d25 | 325 | warning (0, "output constraint %qc for operand %d " |
971801ff | 326 | "is not at the beginning", |
40b18c0a MM |
327 | *p, operand_num); |
328 | ||
329 | /* Make a copy of the constraint. */ | |
1634b18f | 330 | buf = XALLOCAVEC (char, c_len + 1); |
40b18c0a MM |
331 | strcpy (buf, constraint); |
332 | /* Swap the first character and the `=' or `+'. */ | |
333 | buf[p - constraint] = buf[0]; | |
334 | /* Make sure the first character is an `='. (Until we do this, | |
335 | it might be a `+'.) */ | |
336 | buf[0] = '='; | |
337 | /* Replace the constraint with the canonicalized string. */ | |
338 | *constraint_p = ggc_alloc_string (buf, c_len); | |
339 | constraint = *constraint_p; | |
340 | } | |
341 | ||
342 | /* Loop through the constraint string. */ | |
97488870 | 343 | for (p = constraint + 1; *p; p += CONSTRAINT_LEN (*p, p)) |
40b18c0a MM |
344 | switch (*p) |
345 | { | |
346 | case '+': | |
347 | case '=': | |
971801ff JM |
348 | error ("operand constraint contains incorrectly positioned " |
349 | "%<+%> or %<=%>"); | |
40b18c0a | 350 | return false; |
786de7eb | 351 | |
40b18c0a MM |
352 | case '%': |
353 | if (operand_num + 1 == ninputs + noutputs) | |
354 | { | |
971801ff | 355 | error ("%<%%%> constraint used with last operand"); |
40b18c0a MM |
356 | return false; |
357 | } | |
358 | break; | |
359 | ||
a4edaf83 | 360 | case 'V': case TARGET_MEM_CONSTRAINT: case 'o': |
40b18c0a MM |
361 | *allows_mem = true; |
362 | break; | |
363 | ||
364 | case '?': case '!': case '*': case '&': case '#': | |
365 | case 'E': case 'F': case 'G': case 'H': | |
366 | case 's': case 'i': case 'n': | |
367 | case 'I': case 'J': case 'K': case 'L': case 'M': | |
368 | case 'N': case 'O': case 'P': case ',': | |
369 | break; | |
370 | ||
371 | case '0': case '1': case '2': case '3': case '4': | |
372 | case '5': case '6': case '7': case '8': case '9': | |
84b72302 | 373 | case '[': |
40b18c0a MM |
374 | error ("matching constraint not valid in output operand"); |
375 | return false; | |
376 | ||
377 | case '<': case '>': | |
378 | /* ??? Before flow, auto inc/dec insns are not supposed to exist, | |
379 | excepting those that expand_call created. So match memory | |
380 | and hope. */ | |
381 | *allows_mem = true; | |
382 | break; | |
383 | ||
384 | case 'g': case 'X': | |
385 | *allows_reg = true; | |
386 | *allows_mem = true; | |
387 | break; | |
786de7eb | 388 | |
40b18c0a MM |
389 | case 'p': case 'r': |
390 | *allows_reg = true; | |
391 | break; | |
392 | ||
393 | default: | |
394 | if (!ISALPHA (*p)) | |
395 | break; | |
97488870 | 396 | if (REG_CLASS_FROM_CONSTRAINT (*p, p) != NO_REGS) |
40b18c0a | 397 | *allows_reg = true; |
97488870 R |
398 | #ifdef EXTRA_CONSTRAINT_STR |
399 | else if (EXTRA_ADDRESS_CONSTRAINT (*p, p)) | |
ccfc6cc8 | 400 | *allows_reg = true; |
97488870 | 401 | else if (EXTRA_MEMORY_CONSTRAINT (*p, p)) |
ccfc6cc8 | 402 | *allows_mem = true; |
40b18c0a MM |
403 | else |
404 | { | |
405 | /* Otherwise we can't assume anything about the nature of | |
406 | the constraint except that it isn't purely registers. | |
407 | Treat it like "g" and hope for the best. */ | |
408 | *allows_reg = true; | |
409 | *allows_mem = true; | |
410 | } | |
411 | #endif | |
412 | break; | |
413 | } | |
414 | ||
415 | return true; | |
416 | } | |
417 | ||
6be2e1f8 RH |
418 | /* Similar, but for input constraints. */ |
419 | ||
1456deaf | 420 | bool |
46c5ad27 AJ |
421 | parse_input_constraint (const char **constraint_p, int input_num, |
422 | int ninputs, int noutputs, int ninout, | |
423 | const char * const * constraints, | |
424 | bool *allows_mem, bool *allows_reg) | |
6be2e1f8 RH |
425 | { |
426 | const char *constraint = *constraint_p; | |
427 | const char *orig_constraint = constraint; | |
428 | size_t c_len = strlen (constraint); | |
429 | size_t j; | |
f3da0ead | 430 | bool saw_match = false; |
6be2e1f8 RH |
431 | |
432 | /* Assume the constraint doesn't allow the use of either | |
433 | a register or memory. */ | |
434 | *allows_mem = false; | |
435 | *allows_reg = false; | |
436 | ||
437 | /* Make sure constraint has neither `=', `+', nor '&'. */ | |
438 | ||
97488870 | 439 | for (j = 0; j < c_len; j += CONSTRAINT_LEN (constraint[j], constraint+j)) |
6be2e1f8 RH |
440 | switch (constraint[j]) |
441 | { | |
442 | case '+': case '=': case '&': | |
443 | if (constraint == orig_constraint) | |
444 | { | |
971801ff | 445 | error ("input operand constraint contains %qc", constraint[j]); |
6be2e1f8 RH |
446 | return false; |
447 | } | |
448 | break; | |
449 | ||
450 | case '%': | |
451 | if (constraint == orig_constraint | |
452 | && input_num + 1 == ninputs - ninout) | |
453 | { | |
971801ff | 454 | error ("%<%%%> constraint used with last operand"); |
6be2e1f8 RH |
455 | return false; |
456 | } | |
457 | break; | |
458 | ||
a4edaf83 | 459 | case 'V': case TARGET_MEM_CONSTRAINT: case 'o': |
6be2e1f8 RH |
460 | *allows_mem = true; |
461 | break; | |
462 | ||
463 | case '<': case '>': | |
464 | case '?': case '!': case '*': case '#': | |
465 | case 'E': case 'F': case 'G': case 'H': | |
466 | case 's': case 'i': case 'n': | |
467 | case 'I': case 'J': case 'K': case 'L': case 'M': | |
468 | case 'N': case 'O': case 'P': case ',': | |
469 | break; | |
470 | ||
471 | /* Whether or not a numeric constraint allows a register is | |
472 | decided by the matching constraint, and so there is no need | |
473 | to do anything special with them. We must handle them in | |
474 | the default case, so that we don't unnecessarily force | |
475 | operands to memory. */ | |
476 | case '0': case '1': case '2': case '3': case '4': | |
477 | case '5': case '6': case '7': case '8': case '9': | |
478 | { | |
479 | char *end; | |
480 | unsigned long match; | |
481 | ||
f3da0ead JM |
482 | saw_match = true; |
483 | ||
6be2e1f8 RH |
484 | match = strtoul (constraint + j, &end, 10); |
485 | if (match >= (unsigned long) noutputs) | |
486 | { | |
487 | error ("matching constraint references invalid operand number"); | |
488 | return false; | |
489 | } | |
490 | ||
491 | /* Try and find the real constraint for this dup. Only do this | |
492 | if the matching constraint is the only alternative. */ | |
493 | if (*end == '\0' | |
494 | && (j == 0 || (j == 1 && constraint[0] == '%'))) | |
495 | { | |
496 | constraint = constraints[match]; | |
497 | *constraint_p = constraint; | |
498 | c_len = strlen (constraint); | |
499 | j = 0; | |
97488870 R |
500 | /* ??? At the end of the loop, we will skip the first part of |
501 | the matched constraint. This assumes not only that the | |
502 | other constraint is an output constraint, but also that | |
503 | the '=' or '+' come first. */ | |
6be2e1f8 RH |
504 | break; |
505 | } | |
506 | else | |
507 | j = end - constraint; | |
97488870 R |
508 | /* Anticipate increment at end of loop. */ |
509 | j--; | |
6be2e1f8 RH |
510 | } |
511 | /* Fall through. */ | |
512 | ||
513 | case 'p': case 'r': | |
514 | *allows_reg = true; | |
515 | break; | |
516 | ||
517 | case 'g': case 'X': | |
518 | *allows_reg = true; | |
519 | *allows_mem = true; | |
520 | break; | |
521 | ||
522 | default: | |
523 | if (! ISALPHA (constraint[j])) | |
524 | { | |
971801ff | 525 | error ("invalid punctuation %qc in constraint", constraint[j]); |
6be2e1f8 RH |
526 | return false; |
527 | } | |
97488870 R |
528 | if (REG_CLASS_FROM_CONSTRAINT (constraint[j], constraint + j) |
529 | != NO_REGS) | |
6be2e1f8 | 530 | *allows_reg = true; |
97488870 R |
531 | #ifdef EXTRA_CONSTRAINT_STR |
532 | else if (EXTRA_ADDRESS_CONSTRAINT (constraint[j], constraint + j)) | |
ccfc6cc8 | 533 | *allows_reg = true; |
97488870 | 534 | else if (EXTRA_MEMORY_CONSTRAINT (constraint[j], constraint + j)) |
ccfc6cc8 | 535 | *allows_mem = true; |
6be2e1f8 RH |
536 | else |
537 | { | |
538 | /* Otherwise we can't assume anything about the nature of | |
539 | the constraint except that it isn't purely registers. | |
540 | Treat it like "g" and hope for the best. */ | |
541 | *allows_reg = true; | |
542 | *allows_mem = true; | |
543 | } | |
544 | #endif | |
545 | break; | |
546 | } | |
547 | ||
f3da0ead | 548 | if (saw_match && !*allows_reg) |
d4ee4d25 | 549 | warning (0, "matching constraint does not allow a register"); |
f3da0ead | 550 | |
6be2e1f8 RH |
551 | return true; |
552 | } | |
553 | ||
91b4415a R |
554 | /* Return DECL iff there's an overlap between *REGS and DECL, where DECL |
555 | can be an asm-declared register. Called via walk_tree. */ | |
acb5d088 | 556 | |
91b4415a R |
557 | static tree |
558 | decl_overlaps_hard_reg_set_p (tree *declp, int *walk_subtrees ATTRIBUTE_UNUSED, | |
559 | void *data) | |
acb5d088 | 560 | { |
91b4415a | 561 | tree decl = *declp; |
1634b18f | 562 | const HARD_REG_SET *const regs = (const HARD_REG_SET *) data; |
91b4415a | 563 | |
3f2de3dc | 564 | if (TREE_CODE (decl) == VAR_DECL) |
acb5d088 | 565 | { |
3f2de3dc | 566 | if (DECL_HARD_REGISTER (decl) |
91b4415a R |
567 | && REG_P (DECL_RTL (decl)) |
568 | && REGNO (DECL_RTL (decl)) < FIRST_PSEUDO_REGISTER) | |
569 | { | |
570 | rtx reg = DECL_RTL (decl); | |
09e18274 RS |
571 | |
572 | if (overlaps_hard_reg_set_p (*regs, GET_MODE (reg), REGNO (reg))) | |
573 | return decl; | |
91b4415a R |
574 | } |
575 | walk_subtrees = 0; | |
61158923 | 576 | } |
3f2de3dc | 577 | else if (TYPE_P (decl) || TREE_CODE (decl) == PARM_DECL) |
91b4415a R |
578 | walk_subtrees = 0; |
579 | return NULL_TREE; | |
61158923 HPN |
580 | } |
581 | ||
91b4415a R |
582 | /* If there is an overlap between *REGS and DECL, return the first overlap |
583 | found. */ | |
584 | tree | |
585 | tree_overlaps_hard_reg_set (tree decl, HARD_REG_SET *regs) | |
586 | { | |
587 | return walk_tree (&decl, decl_overlaps_hard_reg_set_p, regs, NULL); | |
588 | } | |
61158923 HPN |
589 | |
590 | /* Check for overlap between registers marked in CLOBBERED_REGS and | |
91b4415a R |
591 | anything inappropriate in T. Emit error and return the register |
592 | variable definition for error, NULL_TREE for ok. */ | |
61158923 HPN |
593 | |
594 | static bool | |
91b4415a | 595 | tree_conflicts_with_clobbers_p (tree t, HARD_REG_SET *clobbered_regs) |
61158923 HPN |
596 | { |
597 | /* Conflicts between asm-declared register variables and the clobber | |
598 | list are not allowed. */ | |
91b4415a R |
599 | tree overlap = tree_overlaps_hard_reg_set (t, clobbered_regs); |
600 | ||
601 | if (overlap) | |
61158923 HPN |
602 | { |
603 | error ("asm-specifier for variable %qs conflicts with asm clobber list", | |
91b4415a | 604 | IDENTIFIER_POINTER (DECL_NAME (overlap))); |
61158923 HPN |
605 | |
606 | /* Reset registerness to stop multiple errors emitted for a single | |
607 | variable. */ | |
91b4415a | 608 | DECL_REGISTER (overlap) = 0; |
61158923 | 609 | return true; |
acb5d088 | 610 | } |
61158923 | 611 | |
acb5d088 HPN |
612 | return false; |
613 | } | |
614 | ||
28d81abb RK |
615 | /* Generate RTL for an asm statement with arguments. |
616 | STRING is the instruction template. | |
617 | OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs. | |
618 | Each output or input has an expression in the TREE_VALUE and | |
fa10beec | 619 | a tree list in TREE_PURPOSE which in turn contains a constraint |
786de7eb | 620 | name in TREE_VALUE (or NULL_TREE) and a constraint string |
2ec37136 | 621 | in TREE_PURPOSE. |
28d81abb RK |
622 | CLOBBERS is a list of STRING_CST nodes each naming a hard register |
623 | that is clobbered by this insn. | |
624 | ||
625 | Not all kinds of lvalue that may appear in OUTPUTS can be stored directly. | |
626 | Some elements of OUTPUTS may be replaced with trees representing temporary | |
627 | values. The caller should copy those temporary values to the originally | |
628 | specified lvalues. | |
629 | ||
630 | VOL nonzero means the insn is volatile; don't optimize it. */ | |
631 | ||
bac6bfc5 | 632 | static void |
46c5ad27 | 633 | expand_asm_operands (tree string, tree outputs, tree inputs, |
177560b2 | 634 | tree clobbers, int vol, location_t locus) |
28d81abb | 635 | { |
84b72302 | 636 | rtvec argvec, constraintvec; |
28d81abb RK |
637 | rtx body; |
638 | int ninputs = list_length (inputs); | |
639 | int noutputs = list_length (outputs); | |
6be2e1f8 | 640 | int ninout; |
b4ccaa16 | 641 | int nclobbers; |
acb5d088 HPN |
642 | HARD_REG_SET clobbered_regs; |
643 | int clobber_conflict_found = 0; | |
28d81abb | 644 | tree tail; |
7dc8b126 | 645 | tree t; |
b3694847 | 646 | int i; |
28d81abb | 647 | /* Vector of RTX's of evaluated output operands. */ |
1634b18f KG |
648 | rtx *output_rtx = XALLOCAVEC (rtx, noutputs); |
649 | int *inout_opnum = XALLOCAVEC (int, noutputs); | |
650 | rtx *real_output_rtx = XALLOCAVEC (rtx, noutputs); | |
651 | enum machine_mode *inout_mode = XALLOCAVEC (enum machine_mode, noutputs); | |
652 | const char **constraints = XALLOCAVEC (const char *, noutputs + ninputs); | |
1b3d8f8a | 653 | int old_generating_concat_p = generating_concat_p; |
28d81abb | 654 | |
e5e809f4 | 655 | /* An ASM with no outputs needs to be treated as volatile, for now. */ |
296f8acc JL |
656 | if (noutputs == 0) |
657 | vol = 1; | |
658 | ||
84b72302 RH |
659 | if (! check_operand_nalternatives (outputs, inputs)) |
660 | return; | |
661 | ||
7dc8b126 JM |
662 | string = resolve_asm_operand_names (string, outputs, inputs); |
663 | ||
664 | /* Collect constraints. */ | |
665 | i = 0; | |
666 | for (t = outputs; t ; t = TREE_CHAIN (t), i++) | |
667 | constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t))); | |
668 | for (t = inputs; t ; t = TREE_CHAIN (t), i++) | |
669 | constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t))); | |
84b72302 | 670 | |
57bcb97a RH |
671 | /* Sometimes we wish to automatically clobber registers across an asm. |
672 | Case in point is when the i386 backend moved from cc0 to a hard reg -- | |
f63d1bf7 | 673 | maintaining source-level compatibility means automatically clobbering |
57bcb97a | 674 | the flags register. */ |
61158923 | 675 | clobbers = targetm.md_asm_clobbers (outputs, inputs, clobbers); |
57bcb97a | 676 | |
b4ccaa16 RS |
677 | /* Count the number of meaningful clobbered registers, ignoring what |
678 | we would ignore later. */ | |
679 | nclobbers = 0; | |
acb5d088 | 680 | CLEAR_HARD_REG_SET (clobbered_regs); |
b4ccaa16 RS |
681 | for (tail = clobbers; tail; tail = TREE_CHAIN (tail)) |
682 | { | |
123b24e7 VR |
683 | const char *regname; |
684 | ||
685 | if (TREE_VALUE (tail) == error_mark_node) | |
686 | return; | |
687 | regname = TREE_STRING_POINTER (TREE_VALUE (tail)); | |
14a774a9 | 688 | |
c09e6498 RS |
689 | i = decode_reg_name (regname); |
690 | if (i >= 0 || i == -4) | |
b4ccaa16 | 691 | ++nclobbers; |
7859e3ac | 692 | else if (i == -2) |
971801ff | 693 | error ("unknown register name %qs in %<asm%>", regname); |
acb5d088 HPN |
694 | |
695 | /* Mark clobbered registers. */ | |
696 | if (i >= 0) | |
e54b4cae | 697 | { |
ea4b7848 | 698 | /* Clobbering the PIC register is an error. */ |
fc555370 | 699 | if (i == (int) PIC_OFFSET_TABLE_REGNUM) |
e54b4cae | 700 | { |
971801ff | 701 | error ("PIC register %qs clobbered in %<asm%>", regname); |
e54b4cae EB |
702 | return; |
703 | } | |
704 | ||
705 | SET_HARD_REG_BIT (clobbered_regs, i); | |
706 | } | |
b4ccaa16 RS |
707 | } |
708 | ||
6be2e1f8 RH |
709 | /* First pass over inputs and outputs checks validity and sets |
710 | mark_addressable if needed. */ | |
711 | ||
712 | ninout = 0; | |
28d81abb RK |
713 | for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) |
714 | { | |
715 | tree val = TREE_VALUE (tail); | |
b50a024d | 716 | tree type = TREE_TYPE (val); |
6be2e1f8 | 717 | const char *constraint; |
40b18c0a MM |
718 | bool is_inout; |
719 | bool allows_reg; | |
720 | bool allows_mem; | |
28d81abb RK |
721 | |
722 | /* If there's an erroneous arg, emit no insn. */ | |
40b18c0a | 723 | if (type == error_mark_node) |
28d81abb RK |
724 | return; |
725 | ||
40b18c0a MM |
726 | /* Try to parse the output constraint. If that fails, there's |
727 | no point in going further. */ | |
6be2e1f8 RH |
728 | constraint = constraints[i]; |
729 | if (!parse_output_constraint (&constraint, i, ninputs, noutputs, | |
730 | &allows_mem, &allows_reg, &is_inout)) | |
731 | return; | |
732 | ||
733 | if (! allows_reg | |
734 | && (allows_mem | |
735 | || is_inout | |
736 | || (DECL_P (val) | |
f8cfc6aa | 737 | && REG_P (DECL_RTL (val)) |
6be2e1f8 | 738 | && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))) |
ae2bcd98 | 739 | lang_hooks.mark_addressable (val); |
6be2e1f8 RH |
740 | |
741 | if (is_inout) | |
742 | ninout++; | |
743 | } | |
744 | ||
745 | ninputs += ninout; | |
746 | if (ninputs + noutputs > MAX_RECOG_OPERANDS) | |
747 | { | |
971801ff | 748 | error ("more than %d operands in %<asm%>", MAX_RECOG_OPERANDS); |
6be2e1f8 RH |
749 | return; |
750 | } | |
751 | ||
752 | for (i = 0, tail = inputs; tail; i++, tail = TREE_CHAIN (tail)) | |
753 | { | |
754 | bool allows_reg, allows_mem; | |
755 | const char *constraint; | |
756 | ||
757 | /* If there's an erroneous arg, emit no insn, because the ASM_INPUT | |
758 | would get VOIDmode and that could cause a crash in reload. */ | |
759 | if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node) | |
760 | return; | |
761 | ||
762 | constraint = constraints[i + noutputs]; | |
763 | if (! parse_input_constraint (&constraint, i, ninputs, noutputs, ninout, | |
764 | constraints, &allows_mem, &allows_reg)) | |
40b18c0a | 765 | return; |
d09a75ae | 766 | |
6be2e1f8 | 767 | if (! allows_reg && allows_mem) |
ae2bcd98 | 768 | lang_hooks.mark_addressable (TREE_VALUE (tail)); |
6be2e1f8 RH |
769 | } |
770 | ||
771 | /* Second pass evaluates arguments. */ | |
772 | ||
773 | ninout = 0; | |
774 | for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) | |
775 | { | |
776 | tree val = TREE_VALUE (tail); | |
777 | tree type = TREE_TYPE (val); | |
778 | bool is_inout; | |
779 | bool allows_reg; | |
780 | bool allows_mem; | |
5b50aa9d | 781 | rtx op; |
41374e13 | 782 | bool ok; |
6be2e1f8 | 783 | |
41374e13 | 784 | ok = parse_output_constraint (&constraints[i], i, ninputs, |
6be2e1f8 | 785 | noutputs, &allows_mem, &allows_reg, |
41374e13 NS |
786 | &is_inout); |
787 | gcc_assert (ok); | |
6be2e1f8 | 788 | |
d09a75ae RK |
789 | /* If an output operand is not a decl or indirect ref and our constraint |
790 | allows a register, make a temporary to act as an intermediate. | |
791 | Make the asm insn write into that, then our caller will copy it to | |
792 | the real output operand. Likewise for promoted variables. */ | |
28d81abb | 793 | |
1b3d8f8a GK |
794 | generating_concat_p = 0; |
795 | ||
947255ed | 796 | real_output_rtx[i] = NULL_RTX; |
1afbe1c4 RH |
797 | if ((TREE_CODE (val) == INDIRECT_REF |
798 | && allows_mem) | |
2f939d94 | 799 | || (DECL_P (val) |
f8cfc6aa JQ |
800 | && (allows_mem || REG_P (DECL_RTL (val))) |
801 | && ! (REG_P (DECL_RTL (val)) | |
d09a75ae | 802 | && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type))) |
11579f33 | 803 | || ! allows_reg |
2a230e9d | 804 | || is_inout) |
d09a75ae | 805 | { |
5b50aa9d | 806 | op = expand_expr (val, NULL_RTX, VOIDmode, EXPAND_WRITE); |
3c0cb5de | 807 | if (MEM_P (op)) |
5b50aa9d | 808 | op = validize_mem (op); |
d09a75ae | 809 | |
3c0cb5de | 810 | if (! allows_reg && !MEM_P (op)) |
d09a75ae | 811 | error ("output number %d not directly addressable", i); |
3c0cb5de | 812 | if ((! allows_mem && MEM_P (op)) |
5b50aa9d | 813 | || GET_CODE (op) == CONCAT) |
947255ed | 814 | { |
ad76cef8 | 815 | real_output_rtx[i] = op; |
5b50aa9d | 816 | op = gen_reg_rtx (GET_MODE (op)); |
11579f33 | 817 | if (is_inout) |
5b50aa9d | 818 | emit_move_insn (op, real_output_rtx[i]); |
947255ed | 819 | } |
d09a75ae | 820 | } |
b50a024d | 821 | else |
e619bb8d | 822 | { |
5b50aa9d RH |
823 | op = assign_temp (type, 0, 0, 1); |
824 | op = validize_mem (op); | |
825 | TREE_VALUE (tail) = make_tree (type, op); | |
b50a024d | 826 | } |
5b50aa9d | 827 | output_rtx[i] = op; |
235c5021 | 828 | |
1b3d8f8a GK |
829 | generating_concat_p = old_generating_concat_p; |
830 | ||
2a230e9d | 831 | if (is_inout) |
235c5021 | 832 | { |
6be2e1f8 | 833 | inout_mode[ninout] = TYPE_MODE (type); |
235c5021 RK |
834 | inout_opnum[ninout++] = i; |
835 | } | |
acb5d088 | 836 | |
91b4415a | 837 | if (tree_conflicts_with_clobbers_p (val, &clobbered_regs)) |
acb5d088 | 838 | clobber_conflict_found = 1; |
28d81abb RK |
839 | } |
840 | ||
84b72302 RH |
841 | /* Make vectors for the expression-rtx, constraint strings, |
842 | and named operands. */ | |
28d81abb RK |
843 | |
844 | argvec = rtvec_alloc (ninputs); | |
84b72302 | 845 | constraintvec = rtvec_alloc (ninputs); |
28d81abb | 846 | |
6462bb43 AO |
847 | body = gen_rtx_ASM_OPERANDS ((noutputs == 0 ? VOIDmode |
848 | : GET_MODE (output_rtx[0])), | |
a396f8ae | 849 | ggc_strdup (TREE_STRING_POINTER (string)), |
84b72302 | 850 | empty_string, 0, argvec, constraintvec, |
6773e15f | 851 | locus); |
c85f7c16 | 852 | |
78418280 | 853 | MEM_VOLATILE_P (body) = vol; |
28d81abb RK |
854 | |
855 | /* Eval the inputs and put them into ARGVEC. | |
856 | Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */ | |
857 | ||
84b72302 | 858 | for (i = 0, tail = inputs; tail; tail = TREE_CHAIN (tail), ++i) |
28d81abb | 859 | { |
6be2e1f8 RH |
860 | bool allows_reg, allows_mem; |
861 | const char *constraint; | |
862 | tree val, type; | |
1f06ee8d | 863 | rtx op; |
41374e13 | 864 | bool ok; |
28d81abb | 865 | |
6be2e1f8 | 866 | constraint = constraints[i + noutputs]; |
41374e13 NS |
867 | ok = parse_input_constraint (&constraint, i, ninputs, noutputs, ninout, |
868 | constraints, &allows_mem, &allows_reg); | |
869 | gcc_assert (ok); | |
2a230e9d | 870 | |
6be2e1f8 | 871 | generating_concat_p = 0; |
65fed0cb | 872 | |
6be2e1f8 RH |
873 | val = TREE_VALUE (tail); |
874 | type = TREE_TYPE (val); | |
6d40c489 RS |
875 | /* EXPAND_INITIALIZER will not generate code for valid initializer |
876 | constants, but will still generate code for other types of operand. | |
877 | This is the behavior we want for constant constraints. */ | |
017e1b43 | 878 | op = expand_expr (val, NULL_RTX, VOIDmode, |
6d40c489 RS |
879 | allows_reg ? EXPAND_NORMAL |
880 | : allows_mem ? EXPAND_MEMORY | |
881 | : EXPAND_INITIALIZER); | |
65fed0cb | 882 | |
1b3d8f8a | 883 | /* Never pass a CONCAT to an ASM. */ |
1b3d8f8a GK |
884 | if (GET_CODE (op) == CONCAT) |
885 | op = force_reg (GET_MODE (op), op); | |
3c0cb5de | 886 | else if (MEM_P (op)) |
5b50aa9d | 887 | op = validize_mem (op); |
1b3d8f8a | 888 | |
eca72963 | 889 | if (asm_operand_ok (op, constraint, NULL) <= 0) |
65fed0cb | 890 | { |
4bbcb8fc | 891 | if (allows_reg && TYPE_MODE (type) != BLKmode) |
6be2e1f8 | 892 | op = force_reg (TYPE_MODE (type), op); |
11579f33 | 893 | else if (!allows_mem) |
d4ee4d25 | 894 | warning (0, "asm operand %d probably doesn%'t match constraints", |
84b72302 | 895 | i + noutputs); |
3c0cb5de | 896 | else if (MEM_P (op)) |
6be2e1f8 | 897 | { |
d50ad6af RH |
898 | /* We won't recognize either volatile memory or memory |
899 | with a queued address as available a memory_operand | |
900 | at this point. Ignore it: clearly this *is* a memory. */ | |
6be2e1f8 | 901 | } |
1f06ee8d | 902 | else |
017e1b43 | 903 | { |
d4ee4d25 | 904 | warning (0, "use of memory input without lvalue in " |
71ed1fdb | 905 | "asm operand %d is deprecated", i + noutputs); |
017e1b43 RH |
906 | |
907 | if (CONSTANT_P (op)) | |
908 | { | |
9c858681 RS |
909 | rtx mem = force_const_mem (TYPE_MODE (type), op); |
910 | if (mem) | |
911 | op = validize_mem (mem); | |
912 | else | |
913 | op = force_reg (TYPE_MODE (type), op); | |
017e1b43 | 914 | } |
f8cfc6aa | 915 | if (REG_P (op) |
9c858681 | 916 | || GET_CODE (op) == SUBREG |
9c858681 | 917 | || GET_CODE (op) == CONCAT) |
017e1b43 RH |
918 | { |
919 | tree qual_type = build_qualified_type (type, | |
920 | (TYPE_QUALS (type) | |
921 | | TYPE_QUAL_CONST)); | |
922 | rtx memloc = assign_temp (qual_type, 1, 1, 1); | |
923 | memloc = validize_mem (memloc); | |
924 | emit_move_insn (memloc, op); | |
925 | op = memloc; | |
926 | } | |
927 | } | |
65fed0cb | 928 | } |
6be2e1f8 | 929 | |
1b3d8f8a | 930 | generating_concat_p = old_generating_concat_p; |
6462bb43 | 931 | ASM_OPERANDS_INPUT (body, i) = op; |
2a230e9d | 932 | |
6462bb43 | 933 | ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, i) |
a396f8ae GK |
934 | = gen_rtx_ASM_INPUT (TYPE_MODE (type), |
935 | ggc_strdup (constraints[i + noutputs])); | |
acb5d088 | 936 | |
91b4415a | 937 | if (tree_conflicts_with_clobbers_p (val, &clobbered_regs)) |
acb5d088 | 938 | clobber_conflict_found = 1; |
28d81abb RK |
939 | } |
940 | ||
14a774a9 RK |
941 | /* Protect all the operands from the queue now that they have all been |
942 | evaluated. */ | |
28d81abb | 943 | |
1b3d8f8a GK |
944 | generating_concat_p = 0; |
945 | ||
4381f7c2 | 946 | /* For in-out operands, copy output rtx to input rtx. */ |
235c5021 RK |
947 | for (i = 0; i < ninout; i++) |
948 | { | |
235c5021 | 949 | int j = inout_opnum[i]; |
84b72302 | 950 | char buffer[16]; |
235c5021 | 951 | |
6462bb43 | 952 | ASM_OPERANDS_INPUT (body, ninputs - ninout + i) |
235c5021 | 953 | = output_rtx[j]; |
84b72302 RH |
954 | |
955 | sprintf (buffer, "%d", j); | |
6462bb43 | 956 | ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, ninputs - ninout + i) |
485bad26 | 957 | = gen_rtx_ASM_INPUT (inout_mode[i], ggc_strdup (buffer)); |
235c5021 RK |
958 | } |
959 | ||
1b3d8f8a GK |
960 | generating_concat_p = old_generating_concat_p; |
961 | ||
28d81abb | 962 | /* Now, for each output, construct an rtx |
84b72302 RH |
963 | (set OUTPUT (asm_operands INSN OUTPUTCONSTRAINT OUTPUTNUMBER |
964 | ARGVEC CONSTRAINTS OPNAMES)) | |
28d81abb RK |
965 | If there is more than one, put them inside a PARALLEL. */ |
966 | ||
967 | if (noutputs == 1 && nclobbers == 0) | |
968 | { | |
a396f8ae | 969 | ASM_OPERANDS_OUTPUT_CONSTRAINT (body) = ggc_strdup (constraints[0]); |
4977bab6 | 970 | emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body)); |
28d81abb | 971 | } |
14a774a9 | 972 | |
28d81abb RK |
973 | else if (noutputs == 0 && nclobbers == 0) |
974 | { | |
975 | /* No output operands: put in a raw ASM_OPERANDS rtx. */ | |
4977bab6 | 976 | emit_insn (body); |
28d81abb | 977 | } |
14a774a9 | 978 | |
28d81abb RK |
979 | else |
980 | { | |
981 | rtx obody = body; | |
982 | int num = noutputs; | |
14a774a9 RK |
983 | |
984 | if (num == 0) | |
985 | num = 1; | |
986 | ||
38a448ca | 987 | body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers)); |
28d81abb RK |
988 | |
989 | /* For each output operand, store a SET. */ | |
28d81abb RK |
990 | for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) |
991 | { | |
992 | XVECEXP (body, 0, i) | |
38a448ca RH |
993 | = gen_rtx_SET (VOIDmode, |
994 | output_rtx[i], | |
c5c76735 | 995 | gen_rtx_ASM_OPERANDS |
6462bb43 | 996 | (GET_MODE (output_rtx[i]), |
a396f8ae GK |
997 | ggc_strdup (TREE_STRING_POINTER (string)), |
998 | ggc_strdup (constraints[i]), | |
999 | i, argvec, constraintvec, locus)); | |
c5c76735 | 1000 | |
28d81abb RK |
1001 | MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol; |
1002 | } | |
1003 | ||
1004 | /* If there are no outputs (but there are some clobbers) | |
1005 | store the bare ASM_OPERANDS into the PARALLEL. */ | |
1006 | ||
1007 | if (i == 0) | |
1008 | XVECEXP (body, 0, i++) = obody; | |
1009 | ||
1010 | /* Store (clobber REG) for each clobbered register specified. */ | |
1011 | ||
b4ccaa16 | 1012 | for (tail = clobbers; tail; tail = TREE_CHAIN (tail)) |
28d81abb | 1013 | { |
47ee9bcb | 1014 | const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail)); |
b4ac57ab | 1015 | int j = decode_reg_name (regname); |
acb5d088 | 1016 | rtx clobbered_reg; |
28d81abb | 1017 | |
b4ac57ab | 1018 | if (j < 0) |
28d81abb | 1019 | { |
c09e6498 | 1020 | if (j == -3) /* `cc', which is not a register */ |
dcfedcd0 RK |
1021 | continue; |
1022 | ||
c09e6498 RS |
1023 | if (j == -4) /* `memory', don't cache memory across asm */ |
1024 | { | |
bffc6177 | 1025 | XVECEXP (body, 0, i++) |
38a448ca | 1026 | = gen_rtx_CLOBBER (VOIDmode, |
c5c76735 JL |
1027 | gen_rtx_MEM |
1028 | (BLKmode, | |
1029 | gen_rtx_SCRATCH (VOIDmode))); | |
c09e6498 RS |
1030 | continue; |
1031 | } | |
1032 | ||
956d6950 | 1033 | /* Ignore unknown register, error already signaled. */ |
cc1f5387 | 1034 | continue; |
28d81abb RK |
1035 | } |
1036 | ||
1037 | /* Use QImode since that's guaranteed to clobber just one reg. */ | |
acb5d088 HPN |
1038 | clobbered_reg = gen_rtx_REG (QImode, j); |
1039 | ||
1040 | /* Do sanity check for overlap between clobbers and respectively | |
1041 | input and outputs that hasn't been handled. Such overlap | |
1042 | should have been detected and reported above. */ | |
1043 | if (!clobber_conflict_found) | |
1044 | { | |
1045 | int opno; | |
1046 | ||
1047 | /* We test the old body (obody) contents to avoid tripping | |
1048 | over the under-construction body. */ | |
1049 | for (opno = 0; opno < noutputs; opno++) | |
1050 | if (reg_overlap_mentioned_p (clobbered_reg, output_rtx[opno])) | |
1051 | internal_error ("asm clobber conflict with output operand"); | |
1052 | ||
1053 | for (opno = 0; opno < ninputs - ninout; opno++) | |
1054 | if (reg_overlap_mentioned_p (clobbered_reg, | |
1055 | ASM_OPERANDS_INPUT (obody, opno))) | |
1056 | internal_error ("asm clobber conflict with input operand"); | |
1057 | } | |
1058 | ||
b4ccaa16 | 1059 | XVECEXP (body, 0, i++) |
acb5d088 | 1060 | = gen_rtx_CLOBBER (VOIDmode, clobbered_reg); |
28d81abb RK |
1061 | } |
1062 | ||
4977bab6 | 1063 | emit_insn (body); |
28d81abb RK |
1064 | } |
1065 | ||
947255ed RH |
1066 | /* For any outputs that needed reloading into registers, spill them |
1067 | back to where they belong. */ | |
1068 | for (i = 0; i < noutputs; ++i) | |
1069 | if (real_output_rtx[i]) | |
1070 | emit_move_insn (real_output_rtx[i], output_rtx[i]); | |
1071 | ||
e3b5732b | 1072 | crtl->has_asm_statement = 1; |
28d81abb RK |
1073 | free_temp_slots (); |
1074 | } | |
84b72302 | 1075 | |
6de9cd9a DN |
1076 | void |
1077 | expand_asm_expr (tree exp) | |
1078 | { | |
1079 | int noutputs, i; | |
1080 | tree outputs, tail; | |
1081 | tree *o; | |
1082 | ||
1083 | if (ASM_INPUT_P (exp)) | |
1084 | { | |
bff4b63d | 1085 | expand_asm_loc (ASM_STRING (exp), ASM_VOLATILE_P (exp), input_location); |
6de9cd9a DN |
1086 | return; |
1087 | } | |
1088 | ||
1089 | outputs = ASM_OUTPUTS (exp); | |
1090 | noutputs = list_length (outputs); | |
1091 | /* o[I] is the place that output number I should be written. */ | |
1092 | o = (tree *) alloca (noutputs * sizeof (tree)); | |
1093 | ||
1094 | /* Record the contents of OUTPUTS before it is modified. */ | |
1095 | for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) | |
1096 | o[i] = TREE_VALUE (tail); | |
1097 | ||
1098 | /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of | |
1099 | OUTPUTS some trees for where the values were actually stored. */ | |
1100 | expand_asm_operands (ASM_STRING (exp), outputs, ASM_INPUTS (exp), | |
1101 | ASM_CLOBBERS (exp), ASM_VOLATILE_P (exp), | |
1102 | input_location); | |
1103 | ||
1104 | /* Copy all the intermediate outputs into the specified outputs. */ | |
1105 | for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) | |
1106 | { | |
1107 | if (o[i] != TREE_VALUE (tail)) | |
1108 | { | |
79f5e442 | 1109 | expand_assignment (o[i], TREE_VALUE (tail), false); |
6de9cd9a DN |
1110 | free_temp_slots (); |
1111 | ||
1112 | /* Restore the original value so that it's correct the next | |
1113 | time we expand this function. */ | |
1114 | TREE_VALUE (tail) = o[i]; | |
1115 | } | |
1116 | } | |
6de9cd9a DN |
1117 | } |
1118 | ||
84b72302 RH |
1119 | /* A subroutine of expand_asm_operands. Check that all operands have |
1120 | the same number of alternatives. Return true if so. */ | |
1121 | ||
1122 | static bool | |
46c5ad27 | 1123 | check_operand_nalternatives (tree outputs, tree inputs) |
84b72302 RH |
1124 | { |
1125 | if (outputs || inputs) | |
1126 | { | |
1127 | tree tmp = TREE_PURPOSE (outputs ? outputs : inputs); | |
1128 | int nalternatives | |
1129 | = n_occurrences (',', TREE_STRING_POINTER (TREE_VALUE (tmp))); | |
1130 | tree next = inputs; | |
1131 | ||
1132 | if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES) | |
1133 | { | |
971801ff | 1134 | error ("too many alternatives in %<asm%>"); |
84b72302 RH |
1135 | return false; |
1136 | } | |
1137 | ||
1138 | tmp = outputs; | |
1139 | while (tmp) | |
1140 | { | |
1141 | const char *constraint | |
1142 | = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tmp))); | |
1143 | ||
1144 | if (n_occurrences (',', constraint) != nalternatives) | |
1145 | { | |
971801ff JM |
1146 | error ("operand constraints for %<asm%> differ " |
1147 | "in number of alternatives"); | |
84b72302 RH |
1148 | return false; |
1149 | } | |
1150 | ||
1151 | if (TREE_CHAIN (tmp)) | |
1152 | tmp = TREE_CHAIN (tmp); | |
1153 | else | |
1154 | tmp = next, next = 0; | |
1155 | } | |
1156 | } | |
1157 | ||
1158 | return true; | |
1159 | } | |
1160 | ||
1161 | /* A subroutine of expand_asm_operands. Check that all operand names | |
1162 | are unique. Return true if so. We rely on the fact that these names | |
1163 | are identifiers, and so have been canonicalized by get_identifier, | |
1164 | so all we need are pointer comparisons. */ | |
1165 | ||
1166 | static bool | |
46c5ad27 | 1167 | check_unique_operand_names (tree outputs, tree inputs) |
84b72302 RH |
1168 | { |
1169 | tree i, j; | |
1170 | ||
1171 | for (i = outputs; i ; i = TREE_CHAIN (i)) | |
1172 | { | |
1173 | tree i_name = TREE_PURPOSE (TREE_PURPOSE (i)); | |
1174 | if (! i_name) | |
1175 | continue; | |
1176 | ||
1177 | for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j)) | |
fc552851 | 1178 | if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j)))) |
84b72302 RH |
1179 | goto failure; |
1180 | } | |
1181 | ||
1182 | for (i = inputs; i ; i = TREE_CHAIN (i)) | |
1183 | { | |
1184 | tree i_name = TREE_PURPOSE (TREE_PURPOSE (i)); | |
1185 | if (! i_name) | |
1186 | continue; | |
1187 | ||
1188 | for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j)) | |
fc552851 | 1189 | if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j)))) |
84b72302 RH |
1190 | goto failure; |
1191 | for (j = outputs; j ; j = TREE_CHAIN (j)) | |
fc552851 | 1192 | if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j)))) |
84b72302 RH |
1193 | goto failure; |
1194 | } | |
1195 | ||
1196 | return true; | |
1197 | ||
1198 | failure: | |
971801ff | 1199 | error ("duplicate asm operand name %qs", |
fc552851 | 1200 | TREE_STRING_POINTER (TREE_PURPOSE (TREE_PURPOSE (i)))); |
84b72302 RH |
1201 | return false; |
1202 | } | |
1203 | ||
1204 | /* A subroutine of expand_asm_operands. Resolve the names of the operands | |
1205 | in *POUTPUTS and *PINPUTS to numbers, and replace the name expansions in | |
1206 | STRING and in the constraints to those numbers. */ | |
1207 | ||
7dc8b126 JM |
1208 | tree |
1209 | resolve_asm_operand_names (tree string, tree outputs, tree inputs) | |
84b72302 | 1210 | { |
7dc8b126 | 1211 | char *buffer; |
84b72302 | 1212 | char *p; |
40209195 | 1213 | const char *c; |
84b72302 RH |
1214 | tree t; |
1215 | ||
1456deaf JM |
1216 | check_unique_operand_names (outputs, inputs); |
1217 | ||
7dc8b126 JM |
1218 | /* Substitute [<name>] in input constraint strings. There should be no |
1219 | named operands in output constraints. */ | |
1220 | for (t = inputs; t ; t = TREE_CHAIN (t)) | |
1221 | { | |
40209195 | 1222 | c = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t))); |
7dc8b126 JM |
1223 | if (strchr (c, '[') != NULL) |
1224 | { | |
1225 | p = buffer = xstrdup (c); | |
1226 | while ((p = strchr (p, '[')) != NULL) | |
1227 | p = resolve_operand_name_1 (p, outputs, inputs); | |
1228 | TREE_VALUE (TREE_PURPOSE (t)) | |
1229 | = build_string (strlen (buffer), buffer); | |
1230 | free (buffer); | |
1231 | } | |
1232 | } | |
1233 | ||
40209195 JM |
1234 | /* Now check for any needed substitutions in the template. */ |
1235 | c = TREE_STRING_POINTER (string); | |
1236 | while ((c = strchr (c, '%')) != NULL) | |
84b72302 | 1237 | { |
40209195 JM |
1238 | if (c[1] == '[') |
1239 | break; | |
1240 | else if (ISALPHA (c[1]) && c[2] == '[') | |
1241 | break; | |
7abcb63a RH |
1242 | else |
1243 | { | |
40209195 | 1244 | c += 1; |
7abcb63a RH |
1245 | continue; |
1246 | } | |
84b72302 RH |
1247 | } |
1248 | ||
40209195 JM |
1249 | if (c) |
1250 | { | |
1251 | /* OK, we need to make a copy so we can perform the substitutions. | |
1252 | Assume that we will not need extra space--we get to remove '[' | |
1253 | and ']', which means we cannot have a problem until we have more | |
1254 | than 999 operands. */ | |
1255 | buffer = xstrdup (TREE_STRING_POINTER (string)); | |
1256 | p = buffer + (c - TREE_STRING_POINTER (string)); | |
caf93cb0 | 1257 | |
40209195 JM |
1258 | while ((p = strchr (p, '%')) != NULL) |
1259 | { | |
1260 | if (p[1] == '[') | |
1261 | p += 1; | |
1262 | else if (ISALPHA (p[1]) && p[2] == '[') | |
1263 | p += 2; | |
1264 | else | |
1265 | { | |
1266 | p += 1; | |
1267 | continue; | |
1268 | } | |
1269 | ||
1270 | p = resolve_operand_name_1 (p, outputs, inputs); | |
1271 | } | |
1272 | ||
1273 | string = build_string (strlen (buffer), buffer); | |
1274 | free (buffer); | |
1275 | } | |
84b72302 | 1276 | |
84b72302 RH |
1277 | return string; |
1278 | } | |
1279 | ||
1280 | /* A subroutine of resolve_operand_names. P points to the '[' for a | |
1281 | potential named operand of the form [<name>]. In place, replace | |
786de7eb | 1282 | the name and brackets with a number. Return a pointer to the |
84b72302 RH |
1283 | balance of the string after substitution. */ |
1284 | ||
1285 | static char * | |
46c5ad27 | 1286 | resolve_operand_name_1 (char *p, tree outputs, tree inputs) |
84b72302 RH |
1287 | { |
1288 | char *q; | |
1289 | int op; | |
1290 | tree t; | |
1291 | size_t len; | |
1292 | ||
1293 | /* Collect the operand name. */ | |
1294 | q = strchr (p, ']'); | |
1295 | if (!q) | |
1296 | { | |
1297 | error ("missing close brace for named operand"); | |
1298 | return strchr (p, '\0'); | |
1299 | } | |
1300 | len = q - p - 1; | |
1301 | ||
1302 | /* Resolve the name to a number. */ | |
1303 | for (op = 0, t = outputs; t ; t = TREE_CHAIN (t), op++) | |
1304 | { | |
fc552851 RS |
1305 | tree name = TREE_PURPOSE (TREE_PURPOSE (t)); |
1306 | if (name) | |
edd1967d | 1307 | { |
fc552851 | 1308 | const char *c = TREE_STRING_POINTER (name); |
edd1967d RH |
1309 | if (strncmp (c, p + 1, len) == 0 && c[len] == '\0') |
1310 | goto found; | |
1311 | } | |
84b72302 RH |
1312 | } |
1313 | for (t = inputs; t ; t = TREE_CHAIN (t), op++) | |
1314 | { | |
fc552851 RS |
1315 | tree name = TREE_PURPOSE (TREE_PURPOSE (t)); |
1316 | if (name) | |
edd1967d | 1317 | { |
fc552851 | 1318 | const char *c = TREE_STRING_POINTER (name); |
edd1967d RH |
1319 | if (strncmp (c, p + 1, len) == 0 && c[len] == '\0') |
1320 | goto found; | |
1321 | } | |
84b72302 RH |
1322 | } |
1323 | ||
1324 | *q = '\0'; | |
971801ff | 1325 | error ("undefined named operand %qs", p + 1); |
84b72302 RH |
1326 | op = 0; |
1327 | found: | |
1328 | ||
1329 | /* Replace the name with the number. Unfortunately, not all libraries | |
1330 | get the return value of sprintf correct, so search for the end of the | |
1331 | generated string by hand. */ | |
1332 | sprintf (p, "%d", op); | |
1333 | p = strchr (p, '\0'); | |
1334 | ||
1335 | /* Verify the no extra buffer space assumption. */ | |
41374e13 | 1336 | gcc_assert (p <= q); |
84b72302 RH |
1337 | |
1338 | /* Shift the rest of the buffer down to fill the gap. */ | |
1339 | memmove (p, q + 1, strlen (q + 1) + 1); | |
1340 | ||
1341 | return p; | |
1342 | } | |
28d81abb | 1343 | \f |
4dfa0342 | 1344 | /* Generate RTL to evaluate the expression EXP. */ |
28d81abb RK |
1345 | |
1346 | void | |
46c5ad27 | 1347 | expand_expr_stmt (tree exp) |
1574ef13 AO |
1348 | { |
1349 | rtx value; | |
1350 | tree type; | |
b6ec8c5f | 1351 | |
49452c07 | 1352 | value = expand_expr (exp, const0_rtx, VOIDmode, EXPAND_NORMAL); |
1574ef13 | 1353 | type = TREE_TYPE (exp); |
28d81abb RK |
1354 | |
1355 | /* If all we do is reference a volatile value in memory, | |
1356 | copy it to a register to be sure it is actually touched. */ | |
3c0cb5de | 1357 | if (value && MEM_P (value) && TREE_THIS_VOLATILE (exp)) |
28d81abb | 1358 | { |
1574ef13 | 1359 | if (TYPE_MODE (type) == VOIDmode) |
6a5bbbe6 | 1360 | ; |
1574ef13 AO |
1361 | else if (TYPE_MODE (type) != BLKmode) |
1362 | value = copy_to_reg (value); | |
28d81abb | 1363 | else |
ddbe9812 RS |
1364 | { |
1365 | rtx lab = gen_label_rtx (); | |
4381f7c2 | 1366 | |
ddbe9812 | 1367 | /* Compare the value with itself to reference it. */ |
1574ef13 | 1368 | emit_cmp_and_jump_insns (value, value, EQ, |
84217346 | 1369 | expand_normal (TYPE_SIZE (type)), |
d43e0b7d | 1370 | BLKmode, 0, lab); |
ddbe9812 RS |
1371 | emit_label (lab); |
1372 | } | |
28d81abb RK |
1373 | } |
1374 | ||
4dfa0342 | 1375 | /* Free any temporaries used to evaluate this expression. */ |
28d81abb | 1376 | free_temp_slots (); |
28d81abb RK |
1377 | } |
1378 | ||
1379 | /* Warn if EXP contains any computations whose results are not used. | |
caf93cb0 | 1380 | Return 1 if a warning is printed; 0 otherwise. LOCUS is the |
b9861bff | 1381 | (potential) location of the expression. */ |
28d81abb | 1382 | |
150a992a | 1383 | int |
fa233e34 | 1384 | warn_if_unused_value (const_tree exp, location_t locus) |
28d81abb | 1385 | { |
b9861bff | 1386 | restart: |
591baeb0 | 1387 | if (TREE_USED (exp) || TREE_NO_WARNING (exp)) |
28d81abb RK |
1388 | return 0; |
1389 | ||
9790cefd RH |
1390 | /* Don't warn about void constructs. This includes casting to void, |
1391 | void function calls, and statement expressions with a final cast | |
1392 | to void. */ | |
1393 | if (VOID_TYPE_P (TREE_TYPE (exp))) | |
1394 | return 0; | |
1395 | ||
607bdeaa PB |
1396 | if (EXPR_HAS_LOCATION (exp)) |
1397 | locus = EXPR_LOCATION (exp); | |
b9861bff | 1398 | |
28d81abb RK |
1399 | switch (TREE_CODE (exp)) |
1400 | { | |
1401 | case PREINCREMENT_EXPR: | |
1402 | case POSTINCREMENT_EXPR: | |
1403 | case PREDECREMENT_EXPR: | |
1404 | case POSTDECREMENT_EXPR: | |
1405 | case MODIFY_EXPR: | |
1406 | case INIT_EXPR: | |
1407 | case TARGET_EXPR: | |
1408 | case CALL_EXPR: | |
81797aba | 1409 | case TRY_CATCH_EXPR: |
28d81abb RK |
1410 | case WITH_CLEANUP_EXPR: |
1411 | case EXIT_EXPR: | |
d3d6f724 | 1412 | case VA_ARG_EXPR: |
28d81abb RK |
1413 | return 0; |
1414 | ||
1415 | case BIND_EXPR: | |
1416 | /* For a binding, warn if no side effect within it. */ | |
b9861bff RH |
1417 | exp = BIND_EXPR_BODY (exp); |
1418 | goto restart; | |
28d81abb | 1419 | |
de73f171 | 1420 | case SAVE_EXPR: |
b9861bff RH |
1421 | exp = TREE_OPERAND (exp, 0); |
1422 | goto restart; | |
de73f171 | 1423 | |
28d81abb RK |
1424 | case TRUTH_ORIF_EXPR: |
1425 | case TRUTH_ANDIF_EXPR: | |
1426 | /* In && or ||, warn if 2nd operand has no side effect. */ | |
b9861bff RH |
1427 | exp = TREE_OPERAND (exp, 1); |
1428 | goto restart; | |
28d81abb RK |
1429 | |
1430 | case COMPOUND_EXPR: | |
b9861bff | 1431 | if (warn_if_unused_value (TREE_OPERAND (exp, 0), locus)) |
28d81abb | 1432 | return 1; |
4d23e509 RS |
1433 | /* Let people do `(foo (), 0)' without a warning. */ |
1434 | if (TREE_CONSTANT (TREE_OPERAND (exp, 1))) | |
1435 | return 0; | |
b9861bff RH |
1436 | exp = TREE_OPERAND (exp, 1); |
1437 | goto restart; | |
28d81abb | 1438 | |
591baeb0 JM |
1439 | case COND_EXPR: |
1440 | /* If this is an expression with side effects, don't warn; this | |
1441 | case commonly appears in macro expansions. */ | |
1442 | if (TREE_SIDE_EFFECTS (exp)) | |
28d81abb | 1443 | return 0; |
591baeb0 | 1444 | goto warn; |
28d81abb | 1445 | |
d1e1adfb JM |
1446 | case INDIRECT_REF: |
1447 | /* Don't warn about automatic dereferencing of references, since | |
1448 | the user cannot control it. */ | |
1449 | if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE) | |
b9861bff RH |
1450 | { |
1451 | exp = TREE_OPERAND (exp, 0); | |
1452 | goto restart; | |
1453 | } | |
4381f7c2 KH |
1454 | /* Fall through. */ |
1455 | ||
28d81abb | 1456 | default: |
ddbe9812 | 1457 | /* Referencing a volatile value is a side effect, so don't warn. */ |
6615c446 | 1458 | if ((DECL_P (exp) || REFERENCE_CLASS_P (exp)) |
ddbe9812 RS |
1459 | && TREE_THIS_VOLATILE (exp)) |
1460 | return 0; | |
8d5e6e25 RK |
1461 | |
1462 | /* If this is an expression which has no operands, there is no value | |
1463 | to be unused. There are no such language-independent codes, | |
1464 | but front ends may define such. */ | |
5039610b | 1465 | if (EXPRESSION_CLASS_P (exp) && TREE_OPERAND_LENGTH (exp) == 0) |
8d5e6e25 RK |
1466 | return 0; |
1467 | ||
591baeb0 | 1468 | warn: |
c5409249 | 1469 | warning (OPT_Wunused_value, "%Hvalue computed is not used", &locus); |
28d81abb RK |
1470 | return 1; |
1471 | } | |
1472 | } | |
28d81abb | 1473 | |
28d81abb RK |
1474 | \f |
1475 | /* Generate RTL to return from the current function, with no value. | |
1476 | (That is, we do not do anything about returning any value.) */ | |
1477 | ||
1478 | void | |
46c5ad27 | 1479 | expand_null_return (void) |
28d81abb | 1480 | { |
4381f7c2 | 1481 | /* If this function was declared to return a value, but we |
bd695e1e | 1482 | didn't, clobber the return registers so that they are not |
a1f300c0 | 1483 | propagated live to the rest of the function. */ |
c13fde05 | 1484 | clobber_return_register (); |
28d81abb | 1485 | |
ac45df5d | 1486 | expand_null_return_1 (); |
28d81abb RK |
1487 | } |
1488 | ||
6e3077c6 EB |
1489 | /* Generate RTL to return directly from the current function. |
1490 | (That is, we bypass any return value.) */ | |
1491 | ||
1492 | void | |
1493 | expand_naked_return (void) | |
1494 | { | |
ac45df5d | 1495 | rtx end_label; |
6e3077c6 EB |
1496 | |
1497 | clear_pending_stack_adjust (); | |
1498 | do_pending_stack_adjust (); | |
6e3077c6 | 1499 | |
ac45df5d | 1500 | end_label = naked_return_label; |
6e3077c6 EB |
1501 | if (end_label == 0) |
1502 | end_label = naked_return_label = gen_label_rtx (); | |
ac45df5d RH |
1503 | |
1504 | emit_jump (end_label); | |
6e3077c6 EB |
1505 | } |
1506 | ||
28d81abb RK |
1507 | /* Generate RTL to return from the current function, with value VAL. */ |
1508 | ||
8d800403 | 1509 | static void |
46c5ad27 | 1510 | expand_value_return (rtx val) |
28d81abb | 1511 | { |
28d81abb RK |
1512 | /* Copy the value to the return location |
1513 | unless it's already there. */ | |
1514 | ||
07a236b6 | 1515 | rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl)); |
28d81abb | 1516 | if (return_reg != val) |
77636079 | 1517 | { |
77636079 | 1518 | tree type = TREE_TYPE (DECL_RESULT (current_function_decl)); |
61f71b34 DD |
1519 | if (targetm.calls.promote_function_return (TREE_TYPE (current_function_decl))) |
1520 | { | |
8df83eae | 1521 | int unsignedp = TYPE_UNSIGNED (type); |
61f71b34 DD |
1522 | enum machine_mode old_mode |
1523 | = DECL_MODE (DECL_RESULT (current_function_decl)); | |
1524 | enum machine_mode mode | |
1525 | = promote_mode (type, old_mode, &unsignedp, 1); | |
1526 | ||
1527 | if (mode != old_mode) | |
1528 | val = convert_modes (mode, old_mode, val, unsignedp); | |
1529 | } | |
14a774a9 | 1530 | if (GET_CODE (return_reg) == PARALLEL) |
6e985040 | 1531 | emit_group_load (return_reg, val, type, int_size_in_bytes (type)); |
14a774a9 | 1532 | else |
77636079 RS |
1533 | emit_move_insn (return_reg, val); |
1534 | } | |
14a774a9 | 1535 | |
ac45df5d | 1536 | expand_null_return_1 (); |
28d81abb RK |
1537 | } |
1538 | ||
ac45df5d | 1539 | /* Output a return with no value. */ |
28d81abb RK |
1540 | |
1541 | static void | |
ac45df5d | 1542 | expand_null_return_1 (void) |
28d81abb | 1543 | { |
28d81abb RK |
1544 | clear_pending_stack_adjust (); |
1545 | do_pending_stack_adjust (); | |
526c334b | 1546 | emit_jump (return_label); |
28d81abb RK |
1547 | } |
1548 | \f | |
1549 | /* Generate RTL to evaluate the expression RETVAL and return it | |
1550 | from the current function. */ | |
1551 | ||
1552 | void | |
46c5ad27 | 1553 | expand_return (tree retval) |
28d81abb | 1554 | { |
19e7881c | 1555 | rtx result_rtl; |
b3694847 | 1556 | rtx val = 0; |
28d81abb | 1557 | tree retval_rhs; |
28d81abb RK |
1558 | |
1559 | /* If function wants no value, give it none. */ | |
1560 | if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE) | |
1561 | { | |
84217346 | 1562 | expand_normal (retval); |
28d81abb RK |
1563 | expand_null_return (); |
1564 | return; | |
1565 | } | |
1566 | ||
ea11ca7e | 1567 | if (retval == error_mark_node) |
c9407e4c MM |
1568 | { |
1569 | /* Treat this like a return of no value from a function that | |
1570 | returns a value. */ | |
1571 | expand_null_return (); | |
786de7eb | 1572 | return; |
c9407e4c | 1573 | } |
726a989a | 1574 | else if ((TREE_CODE (retval) == MODIFY_EXPR |
ac45df5d | 1575 | || TREE_CODE (retval) == INIT_EXPR) |
726a989a RB |
1576 | && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL) |
1577 | retval_rhs = TREE_OPERAND (retval, 1); | |
28d81abb | 1578 | else |
6de9cd9a | 1579 | retval_rhs = retval; |
28d81abb | 1580 | |
19e7881c MM |
1581 | result_rtl = DECL_RTL (DECL_RESULT (current_function_decl)); |
1582 | ||
6f4a43e0 ZW |
1583 | /* If we are returning the RESULT_DECL, then the value has already |
1584 | been stored into it, so we don't have to do anything special. */ | |
1585 | if (TREE_CODE (retval_rhs) == RESULT_DECL) | |
1586 | expand_value_return (result_rtl); | |
1587 | ||
4c485b63 JL |
1588 | /* If the result is an aggregate that is being returned in one (or more) |
1589 | registers, load the registers here. The compiler currently can't handle | |
1590 | copying a BLKmode value into registers. We could put this code in a | |
1591 | more general area (for use by everyone instead of just function | |
1592 | call/return), but until this feature is generally usable it is kept here | |
ac45df5d | 1593 | (and in expand_call). */ |
4c485b63 | 1594 | |
6f4a43e0 | 1595 | else if (retval_rhs != 0 |
726a989a | 1596 | && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode |
6f4a43e0 | 1597 | && REG_P (result_rtl)) |
4c485b63 | 1598 | { |
770ae6cc RK |
1599 | int i; |
1600 | unsigned HOST_WIDE_INT bitpos, xbitpos; | |
c988af2b | 1601 | unsigned HOST_WIDE_INT padding_correction = 0; |
770ae6cc RK |
1602 | unsigned HOST_WIDE_INT bytes |
1603 | = int_size_in_bytes (TREE_TYPE (retval_rhs)); | |
4c485b63 | 1604 | int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD; |
770ae6cc RK |
1605 | unsigned int bitsize |
1606 | = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), BITS_PER_WORD); | |
1634b18f | 1607 | rtx *result_pseudos = XALLOCAVEC (rtx, n_regs); |
c16ddde3 | 1608 | rtx result_reg, src = NULL_RTX, dst = NULL_RTX; |
84217346 | 1609 | rtx result_val = expand_normal (retval_rhs); |
af55da56 | 1610 | enum machine_mode tmpmode, result_reg_mode; |
4c485b63 | 1611 | |
2954d7db RK |
1612 | if (bytes == 0) |
1613 | { | |
1614 | expand_null_return (); | |
1615 | return; | |
1616 | } | |
1617 | ||
c988af2b RS |
1618 | /* If the structure doesn't take up a whole number of words, see |
1619 | whether the register value should be padded on the left or on | |
1620 | the right. Set PADDING_CORRECTION to the number of padding | |
1621 | bits needed on the left side. | |
1622 | ||
1623 | In most ABIs, the structure will be returned at the least end of | |
1624 | the register, which translates to right padding on little-endian | |
1625 | targets and left padding on big-endian targets. The opposite | |
1626 | holds if the structure is returned at the most significant | |
1627 | end of the register. */ | |
1628 | if (bytes % UNITS_PER_WORD != 0 | |
1629 | && (targetm.calls.return_in_msb (TREE_TYPE (retval_rhs)) | |
1630 | ? !BYTES_BIG_ENDIAN | |
1631 | : BYTES_BIG_ENDIAN)) | |
1632 | padding_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD) | |
1633 | * BITS_PER_UNIT)); | |
a7f875d7 | 1634 | |
4381f7c2 | 1635 | /* Copy the structure BITSIZE bits at a time. */ |
c988af2b | 1636 | for (bitpos = 0, xbitpos = padding_correction; |
a7f875d7 RK |
1637 | bitpos < bytes * BITS_PER_UNIT; |
1638 | bitpos += bitsize, xbitpos += bitsize) | |
4c485b63 | 1639 | { |
a7f875d7 | 1640 | /* We need a new destination pseudo each time xbitpos is |
c988af2b | 1641 | on a word boundary and when xbitpos == padding_correction |
a7f875d7 RK |
1642 | (the first time through). */ |
1643 | if (xbitpos % BITS_PER_WORD == 0 | |
c988af2b | 1644 | || xbitpos == padding_correction) |
4c485b63 | 1645 | { |
a7f875d7 RK |
1646 | /* Generate an appropriate register. */ |
1647 | dst = gen_reg_rtx (word_mode); | |
1648 | result_pseudos[xbitpos / BITS_PER_WORD] = dst; | |
1649 | ||
8a38ed86 AM |
1650 | /* Clear the destination before we move anything into it. */ |
1651 | emit_move_insn (dst, CONST0_RTX (GET_MODE (dst))); | |
4c485b63 | 1652 | } |
a7f875d7 RK |
1653 | |
1654 | /* We need a new source operand each time bitpos is on a word | |
1655 | boundary. */ | |
1656 | if (bitpos % BITS_PER_WORD == 0) | |
1657 | src = operand_subword_force (result_val, | |
1658 | bitpos / BITS_PER_WORD, | |
1659 | BLKmode); | |
1660 | ||
1661 | /* Use bitpos for the source extraction (left justified) and | |
1662 | xbitpos for the destination store (right justified). */ | |
1663 | store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode, | |
1664 | extract_bit_field (src, bitsize, | |
1665 | bitpos % BITS_PER_WORD, 1, | |
b3520980 | 1666 | NULL_RTX, word_mode, word_mode)); |
4c485b63 JL |
1667 | } |
1668 | ||
c988af2b RS |
1669 | tmpmode = GET_MODE (result_rtl); |
1670 | if (tmpmode == BLKmode) | |
1671 | { | |
1672 | /* Find the smallest integer mode large enough to hold the | |
1673 | entire structure and use that mode instead of BLKmode | |
1674 | on the USE insn for the return register. */ | |
1675 | for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT); | |
1676 | tmpmode != VOIDmode; | |
1677 | tmpmode = GET_MODE_WIDER_MODE (tmpmode)) | |
1678 | /* Have we found a large enough mode? */ | |
1679 | if (GET_MODE_SIZE (tmpmode) >= bytes) | |
1680 | break; | |
4c485b63 | 1681 | |
41374e13 NS |
1682 | /* A suitable mode should have been found. */ |
1683 | gcc_assert (tmpmode != VOIDmode); | |
4c485b63 | 1684 | |
c988af2b RS |
1685 | PUT_MODE (result_rtl, tmpmode); |
1686 | } | |
3ffeb8f1 | 1687 | |
af55da56 JW |
1688 | if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode)) |
1689 | result_reg_mode = word_mode; | |
1690 | else | |
1691 | result_reg_mode = tmpmode; | |
1692 | result_reg = gen_reg_rtx (result_reg_mode); | |
1693 | ||
3ffeb8f1 | 1694 | for (i = 0; i < n_regs; i++) |
af55da56 | 1695 | emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode), |
3ffeb8f1 | 1696 | result_pseudos[i]); |
4c485b63 | 1697 | |
af55da56 JW |
1698 | if (tmpmode != result_reg_mode) |
1699 | result_reg = gen_lowpart (tmpmode, result_reg); | |
1700 | ||
4c485b63 JL |
1701 | expand_value_return (result_reg); |
1702 | } | |
7cc8342c RH |
1703 | else if (retval_rhs != 0 |
1704 | && !VOID_TYPE_P (TREE_TYPE (retval_rhs)) | |
f8cfc6aa | 1705 | && (REG_P (result_rtl) |
7cc8342c | 1706 | || (GET_CODE (result_rtl) == PARALLEL))) |
28d81abb | 1707 | { |
14a774a9 RK |
1708 | /* Calculate the return value into a temporary (usually a pseudo |
1709 | reg). */ | |
1da68f56 RK |
1710 | tree ot = TREE_TYPE (DECL_RESULT (current_function_decl)); |
1711 | tree nt = build_qualified_type (ot, TYPE_QUALS (ot) | TYPE_QUAL_CONST); | |
1712 | ||
1713 | val = assign_temp (nt, 0, 0, 1); | |
49452c07 | 1714 | val = expand_expr (retval_rhs, val, GET_MODE (val), EXPAND_NORMAL); |
dd98f85c | 1715 | val = force_not_mem (val); |
ac45df5d | 1716 | /* Return the calculated value. */ |
bef5d8b6 | 1717 | expand_value_return (val); |
28d81abb RK |
1718 | } |
1719 | else | |
1720 | { | |
ac45df5d | 1721 | /* No hard reg used; calculate value into hard return reg. */ |
49452c07 | 1722 | expand_expr (retval, const0_rtx, VOIDmode, EXPAND_NORMAL); |
14a774a9 | 1723 | expand_value_return (result_rtl); |
28d81abb RK |
1724 | } |
1725 | } | |
28d81abb | 1726 | \f |
ba716ac9 BS |
1727 | /* Emit code to restore vital registers at the beginning of a nonlocal goto |
1728 | handler. */ | |
1729 | static void | |
46c5ad27 | 1730 | expand_nl_goto_receiver (void) |
ba716ac9 | 1731 | { |
6de9cd9a | 1732 | /* Clobber the FP when we get here, so we have to make sure it's |
e292dbb0 | 1733 | marked as used by this function. */ |
c41c1387 | 1734 | emit_use (hard_frame_pointer_rtx); |
e292dbb0 WH |
1735 | |
1736 | /* Mark the static chain as clobbered here so life information | |
1737 | doesn't get messed up for it. */ | |
c41c1387 | 1738 | emit_clobber (static_chain_rtx); |
e292dbb0 | 1739 | |
ba716ac9 BS |
1740 | #ifdef HAVE_nonlocal_goto |
1741 | if (! HAVE_nonlocal_goto) | |
1742 | #endif | |
1743 | /* First adjust our frame pointer to its actual value. It was | |
1744 | previously set to the start of the virtual area corresponding to | |
1745 | the stacked variables when we branched here and now needs to be | |
1746 | adjusted to the actual hardware fp value. | |
1747 | ||
1748 | Assignments are to virtual registers are converted by | |
1749 | instantiate_virtual_regs into the corresponding assignment | |
1750 | to the underlying register (fp in this case) that makes | |
1751 | the original assignment true. | |
1752 | So the following insn will actually be | |
1753 | decrementing fp by STARTING_FRAME_OFFSET. */ | |
1754 | emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx); | |
1755 | ||
1756 | #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM | |
1757 | if (fixed_regs[ARG_POINTER_REGNUM]) | |
1758 | { | |
1759 | #ifdef ELIMINABLE_REGS | |
1760 | /* If the argument pointer can be eliminated in favor of the | |
1761 | frame pointer, we don't need to restore it. We assume here | |
1762 | that if such an elimination is present, it can always be used. | |
1763 | This is the case on all known machines; if we don't make this | |
1764 | assumption, we do unnecessary saving on many machines. */ | |
8b60264b | 1765 | static const struct elims {const int from, to;} elim_regs[] = ELIMINABLE_REGS; |
ba716ac9 BS |
1766 | size_t i; |
1767 | ||
b6a1cbae | 1768 | for (i = 0; i < ARRAY_SIZE (elim_regs); i++) |
ba716ac9 BS |
1769 | if (elim_regs[i].from == ARG_POINTER_REGNUM |
1770 | && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM) | |
1771 | break; | |
1772 | ||
b6a1cbae | 1773 | if (i == ARRAY_SIZE (elim_regs)) |
ba716ac9 BS |
1774 | #endif |
1775 | { | |
1776 | /* Now restore our arg pointer from the address at which it | |
278ed218 | 1777 | was saved in our stack frame. */ |
2e3f842f | 1778 | emit_move_insn (crtl->args.internal_arg_pointer, |
bd60bab2 | 1779 | copy_to_reg (get_arg_pointer_save_area ())); |
ba716ac9 BS |
1780 | } |
1781 | } | |
1782 | #endif | |
1783 | ||
1784 | #ifdef HAVE_nonlocal_goto_receiver | |
1785 | if (HAVE_nonlocal_goto_receiver) | |
1786 | emit_insn (gen_nonlocal_goto_receiver ()); | |
1787 | #endif | |
e292dbb0 | 1788 | |
6fb5fa3c DB |
1789 | /* We must not allow the code we just generated to be reordered by |
1790 | scheduling. Specifically, the update of the frame pointer must | |
1791 | happen immediately, not later. */ | |
1792 | emit_insn (gen_blockage ()); | |
ba716ac9 | 1793 | } |
28d81abb RK |
1794 | \f |
1795 | /* Generate RTL for the automatic variable declaration DECL. | |
ec5cd386 | 1796 | (Other kinds of declarations are simply ignored if seen here.) */ |
28d81abb RK |
1797 | |
1798 | void | |
46c5ad27 | 1799 | expand_decl (tree decl) |
28d81abb | 1800 | { |
ca695ac9 JB |
1801 | tree type; |
1802 | ||
ca695ac9 | 1803 | type = TREE_TYPE (decl); |
28d81abb | 1804 | |
eabb9ed0 RK |
1805 | /* For a CONST_DECL, set mode, alignment, and sizes from those of the |
1806 | type in case this node is used in a reference. */ | |
1807 | if (TREE_CODE (decl) == CONST_DECL) | |
1808 | { | |
1809 | DECL_MODE (decl) = TYPE_MODE (type); | |
1810 | DECL_ALIGN (decl) = TYPE_ALIGN (type); | |
1811 | DECL_SIZE (decl) = TYPE_SIZE (type); | |
1812 | DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (type); | |
1813 | return; | |
1814 | } | |
28d81abb | 1815 | |
eabb9ed0 RK |
1816 | /* Otherwise, only automatic variables need any expansion done. Static and |
1817 | external variables, and external functions, will be handled by | |
1818 | `assemble_variable' (called from finish_decl). TYPE_DECL requires | |
1819 | nothing. PARM_DECLs are handled in `assign_parms'. */ | |
28d81abb RK |
1820 | if (TREE_CODE (decl) != VAR_DECL) |
1821 | return; | |
eabb9ed0 | 1822 | |
44fe2e80 | 1823 | if (TREE_STATIC (decl) || DECL_EXTERNAL (decl)) |
28d81abb RK |
1824 | return; |
1825 | ||
1826 | /* Create the RTL representation for the variable. */ | |
1827 | ||
1828 | if (type == error_mark_node) | |
19e7881c | 1829 | SET_DECL_RTL (decl, gen_rtx_MEM (BLKmode, const0_rtx)); |
1da68f56 | 1830 | |
28d81abb | 1831 | else if (DECL_SIZE (decl) == 0) |
28d81abb | 1832 | { |
b38f3813 | 1833 | /* Variable with incomplete type. */ |
abde42f7 | 1834 | rtx x; |
28d81abb RK |
1835 | if (DECL_INITIAL (decl) == 0) |
1836 | /* Error message was already done; now avoid a crash. */ | |
abde42f7 | 1837 | x = gen_rtx_MEM (BLKmode, const0_rtx); |
28d81abb RK |
1838 | else |
1839 | /* An initializer is going to decide the size of this array. | |
1840 | Until we know the size, represent its address with a reg. */ | |
abde42f7 | 1841 | x = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode)); |
3bdf5ad1 | 1842 | |
abde42f7 JH |
1843 | set_mem_attributes (x, decl, 1); |
1844 | SET_DECL_RTL (decl, x); | |
28d81abb | 1845 | } |
8fff4fc1 | 1846 | else if (use_register_for_decl (decl)) |
28d81abb RK |
1847 | { |
1848 | /* Automatic variable that can go in a register. */ | |
8df83eae | 1849 | int unsignedp = TYPE_UNSIGNED (type); |
28612f9e RK |
1850 | enum machine_mode reg_mode |
1851 | = promote_mode (type, DECL_MODE (decl), &unsignedp, 0); | |
98f3b471 | 1852 | |
19e7881c | 1853 | SET_DECL_RTL (decl, gen_reg_rtx (reg_mode)); |
0d4903b8 | 1854 | |
0b068ee9 | 1855 | /* Note if the object is a user variable. */ |
7dc8b126 | 1856 | if (!DECL_ARTIFICIAL (decl)) |
0b068ee9 JL |
1857 | mark_user_reg (DECL_RTL (decl)); |
1858 | ||
61021c2c AP |
1859 | if (POINTER_TYPE_P (type)) |
1860 | mark_reg_pointer (DECL_RTL (decl), | |
1861 | TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl)))); | |
28d81abb | 1862 | } |
0df15c2c | 1863 | |
b38f3813 | 1864 | else |
28d81abb | 1865 | { |
28d81abb RK |
1866 | rtx oldaddr = 0; |
1867 | rtx addr; | |
0d4903b8 | 1868 | rtx x; |
28d81abb | 1869 | |
b38f3813 EB |
1870 | /* Variable-sized decls are dealt with in the gimplifier. */ |
1871 | gcc_assert (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST); | |
1872 | ||
28d81abb RK |
1873 | /* If we previously made RTL for this decl, it must be an array |
1874 | whose size was determined by the initializer. | |
1875 | The old address was a register; set that register now | |
1876 | to the proper address. */ | |
19e7881c | 1877 | if (DECL_RTL_SET_P (decl)) |
28d81abb | 1878 | { |
41374e13 NS |
1879 | gcc_assert (MEM_P (DECL_RTL (decl))); |
1880 | gcc_assert (REG_P (XEXP (DECL_RTL (decl), 0))); | |
28d81abb RK |
1881 | oldaddr = XEXP (DECL_RTL (decl), 0); |
1882 | } | |
1883 | ||
28d81abb RK |
1884 | /* Set alignment we actually gave this decl. */ |
1885 | DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT | |
1886 | : GET_MODE_BITSIZE (DECL_MODE (decl))); | |
11cf4d18 | 1887 | DECL_USER_ALIGN (decl) = 0; |
28d81abb | 1888 | |
9432c136 | 1889 | x = assign_temp (decl, 1, 1, 1); |
0d4903b8 RK |
1890 | set_mem_attributes (x, decl, 1); |
1891 | SET_DECL_RTL (decl, x); | |
1892 | ||
28d81abb RK |
1893 | if (oldaddr) |
1894 | { | |
1895 | addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr); | |
1896 | if (addr != oldaddr) | |
1897 | emit_move_insn (oldaddr, addr); | |
1898 | } | |
28d81abb | 1899 | } |
28d81abb RK |
1900 | } |
1901 | \f | |
6de9cd9a DN |
1902 | /* Emit code to save the current value of stack. */ |
1903 | rtx | |
1904 | expand_stack_save (void) | |
1905 | { | |
1906 | rtx ret = NULL_RTX; | |
1907 | ||
1908 | do_pending_stack_adjust (); | |
1909 | emit_stack_save (SAVE_BLOCK, &ret, NULL_RTX); | |
1910 | return ret; | |
1911 | } | |
1912 | ||
1913 | /* Emit code to restore the current value of stack. */ | |
1914 | void | |
1915 | expand_stack_restore (tree var) | |
1916 | { | |
b9f9b210 | 1917 | rtx sa = expand_normal (var); |
6de9cd9a | 1918 | |
41ccb5d1 | 1919 | sa = convert_memory_address (Pmode, sa); |
6de9cd9a DN |
1920 | emit_stack_restore (SAVE_BLOCK, sa, NULL_RTX); |
1921 | } | |
28d81abb | 1922 | \f |
7efcb746 PB |
1923 | /* Do the insertion of a case label into case_list. The labels are |
1924 | fed to us in descending order from the sorted vector of case labels used | |
a6c0a76c | 1925 | in the tree part of the middle end. So the list we construct is |
eb172681 RS |
1926 | sorted in ascending order. The bounds on the case range, LOW and HIGH, |
1927 | are converted to case's index type TYPE. */ | |
57641239 | 1928 | |
eb172681 RS |
1929 | static struct case_node * |
1930 | add_case_node (struct case_node *head, tree type, tree low, tree high, | |
6ac1b3a4 | 1931 | tree label, alloc_pool case_node_pool) |
57641239 | 1932 | { |
eb172681 | 1933 | tree min_value, max_value; |
a6c0a76c | 1934 | struct case_node *r; |
57641239 | 1935 | |
eb172681 RS |
1936 | gcc_assert (TREE_CODE (low) == INTEGER_CST); |
1937 | gcc_assert (!high || TREE_CODE (high) == INTEGER_CST); | |
1938 | ||
1939 | min_value = TYPE_MIN_VALUE (type); | |
1940 | max_value = TYPE_MAX_VALUE (type); | |
1941 | ||
56cb9733 MM |
1942 | /* If there's no HIGH value, then this is not a case range; it's |
1943 | just a simple case label. But that's just a degenerate case | |
a6c0a76c SB |
1944 | range. |
1945 | If the bounds are equal, turn this into the one-value case. */ | |
1946 | if (!high || tree_int_cst_equal (low, high)) | |
eb172681 RS |
1947 | { |
1948 | /* If the simple case value is unreachable, ignore it. */ | |
b77aa1f7 AP |
1949 | if ((TREE_CODE (min_value) == INTEGER_CST |
1950 | && tree_int_cst_compare (low, min_value) < 0) | |
1951 | || (TREE_CODE (max_value) == INTEGER_CST | |
1952 | && tree_int_cst_compare (low, max_value) > 0)) | |
eb172681 RS |
1953 | return head; |
1954 | low = fold_convert (type, low); | |
1955 | high = low; | |
1956 | } | |
1957 | else | |
1958 | { | |
1959 | /* If the entire case range is unreachable, ignore it. */ | |
b77aa1f7 AP |
1960 | if ((TREE_CODE (min_value) == INTEGER_CST |
1961 | && tree_int_cst_compare (high, min_value) < 0) | |
1962 | || (TREE_CODE (max_value) == INTEGER_CST | |
1963 | && tree_int_cst_compare (low, max_value) > 0)) | |
eb172681 RS |
1964 | return head; |
1965 | ||
1966 | /* If the lower bound is less than the index type's minimum | |
1967 | value, truncate the range bounds. */ | |
b77aa1f7 AP |
1968 | if (TREE_CODE (min_value) == INTEGER_CST |
1969 | && tree_int_cst_compare (low, min_value) < 0) | |
eb172681 RS |
1970 | low = min_value; |
1971 | low = fold_convert (type, low); | |
1972 | ||
1973 | /* If the upper bound is greater than the index type's maximum | |
1974 | value, truncate the range bounds. */ | |
b77aa1f7 AP |
1975 | if (TREE_CODE (max_value) == INTEGER_CST |
1976 | && tree_int_cst_compare (high, max_value) > 0) | |
eb172681 RS |
1977 | high = max_value; |
1978 | high = fold_convert (type, high); | |
1979 | } | |
1980 | ||
56cb9733 | 1981 | |
b2ecb7a8 | 1982 | /* Add this label to the chain. Make sure to drop overflow flags. */ |
6ac1b3a4 | 1983 | r = (struct case_node *) pool_alloc (case_node_pool); |
b2ecb7a8 RG |
1984 | r->low = build_int_cst_wide (TREE_TYPE (low), TREE_INT_CST_LOW (low), |
1985 | TREE_INT_CST_HIGH (low)); | |
1986 | r->high = build_int_cst_wide (TREE_TYPE (high), TREE_INT_CST_LOW (high), | |
1987 | TREE_INT_CST_HIGH (high)); | |
57641239 | 1988 | r->code_label = label; |
a6c0a76c | 1989 | r->parent = r->left = NULL; |
7efcb746 PB |
1990 | r->right = head; |
1991 | return r; | |
28d81abb | 1992 | } |
28d81abb | 1993 | \f |
9bb231fd RS |
1994 | /* Maximum number of case bit tests. */ |
1995 | #define MAX_CASE_BIT_TESTS 3 | |
1996 | ||
1997 | /* By default, enable case bit tests on targets with ashlsi3. */ | |
1998 | #ifndef CASE_USE_BIT_TESTS | |
166cdb08 | 1999 | #define CASE_USE_BIT_TESTS (optab_handler (ashl_optab, word_mode)->insn_code \ |
9bb231fd RS |
2000 | != CODE_FOR_nothing) |
2001 | #endif | |
2002 | ||
2003 | ||
2004 | /* A case_bit_test represents a set of case nodes that may be | |
2005 | selected from using a bit-wise comparison. HI and LO hold | |
2006 | the integer to be tested against, LABEL contains the label | |
2007 | to jump to upon success and BITS counts the number of case | |
2008 | nodes handled by this test, typically the number of bits | |
2009 | set in HI:LO. */ | |
2010 | ||
2011 | struct case_bit_test | |
2012 | { | |
2013 | HOST_WIDE_INT hi; | |
2014 | HOST_WIDE_INT lo; | |
2015 | rtx label; | |
2016 | int bits; | |
2017 | }; | |
2018 | ||
2019 | /* Determine whether "1 << x" is relatively cheap in word_mode. */ | |
2020 | ||
7e51717c AJ |
2021 | static |
2022 | bool lshift_cheap_p (void) | |
9bb231fd RS |
2023 | { |
2024 | static bool init = false; | |
2025 | static bool cheap = true; | |
2026 | ||
2027 | if (!init) | |
2028 | { | |
2029 | rtx reg = gen_rtx_REG (word_mode, 10000); | |
f40751dd JH |
2030 | int cost = rtx_cost (gen_rtx_ASHIFT (word_mode, const1_rtx, reg), SET, |
2031 | optimize_insn_for_speed_p ()); | |
9bb231fd RS |
2032 | cheap = cost < COSTS_N_INSNS (3); |
2033 | init = true; | |
2034 | } | |
2035 | ||
2036 | return cheap; | |
2037 | } | |
2038 | ||
2039 | /* Comparison function for qsort to order bit tests by decreasing | |
2040 | number of case nodes, i.e. the node with the most cases gets | |
2041 | tested first. */ | |
2042 | ||
f667741c SB |
2043 | static int |
2044 | case_bit_test_cmp (const void *p1, const void *p2) | |
9bb231fd | 2045 | { |
1634b18f KG |
2046 | const struct case_bit_test *const d1 = (const struct case_bit_test *) p1; |
2047 | const struct case_bit_test *const d2 = (const struct case_bit_test *) p2; | |
9bb231fd | 2048 | |
0174997a RS |
2049 | if (d2->bits != d1->bits) |
2050 | return d2->bits - d1->bits; | |
2051 | ||
2052 | /* Stabilize the sort. */ | |
2053 | return CODE_LABEL_NUMBER (d2->label) - CODE_LABEL_NUMBER (d1->label); | |
9bb231fd RS |
2054 | } |
2055 | ||
2056 | /* Expand a switch statement by a short sequence of bit-wise | |
2057 | comparisons. "switch(x)" is effectively converted into | |
2058 | "if ((1 << (x-MINVAL)) & CST)" where CST and MINVAL are | |
2059 | integer constants. | |
2060 | ||
2061 | INDEX_EXPR is the value being switched on, which is of | |
2062 | type INDEX_TYPE. MINVAL is the lowest case value of in | |
2063 | the case nodes, of INDEX_TYPE type, and RANGE is highest | |
2064 | value minus MINVAL, also of type INDEX_TYPE. NODES is | |
2065 | the set of case nodes, and DEFAULT_LABEL is the label to | |
2066 | branch to should none of the cases match. | |
2067 | ||
2068 | There *MUST* be MAX_CASE_BIT_TESTS or less unique case | |
2069 | node targets. */ | |
2070 | ||
2071 | static void | |
46c5ad27 AJ |
2072 | emit_case_bit_tests (tree index_type, tree index_expr, tree minval, |
2073 | tree range, case_node_ptr nodes, rtx default_label) | |
9bb231fd RS |
2074 | { |
2075 | struct case_bit_test test[MAX_CASE_BIT_TESTS]; | |
2076 | enum machine_mode mode; | |
2077 | rtx expr, index, label; | |
2078 | unsigned int i,j,lo,hi; | |
2079 | struct case_node *n; | |
2080 | unsigned int count; | |
2081 | ||
2082 | count = 0; | |
2083 | for (n = nodes; n; n = n->right) | |
2084 | { | |
2085 | label = label_rtx (n->code_label); | |
2086 | for (i = 0; i < count; i++) | |
7efcb746 | 2087 | if (label == test[i].label) |
9bb231fd RS |
2088 | break; |
2089 | ||
2090 | if (i == count) | |
2091 | { | |
41374e13 NS |
2092 | gcc_assert (count < MAX_CASE_BIT_TESTS); |
2093 | test[i].hi = 0; | |
2094 | test[i].lo = 0; | |
9bb231fd RS |
2095 | test[i].label = label; |
2096 | test[i].bits = 1; | |
2097 | count++; | |
2098 | } | |
2099 | else | |
2100 | test[i].bits++; | |
2101 | ||
4845b383 KH |
2102 | lo = tree_low_cst (fold_build2 (MINUS_EXPR, index_type, |
2103 | n->low, minval), 1); | |
2104 | hi = tree_low_cst (fold_build2 (MINUS_EXPR, index_type, | |
2105 | n->high, minval), 1); | |
9bb231fd RS |
2106 | for (j = lo; j <= hi; j++) |
2107 | if (j >= HOST_BITS_PER_WIDE_INT) | |
2108 | test[i].hi |= (HOST_WIDE_INT) 1 << (j - HOST_BITS_PER_INT); | |
2109 | else | |
2110 | test[i].lo |= (HOST_WIDE_INT) 1 << j; | |
2111 | } | |
2112 | ||
2113 | qsort (test, count, sizeof(*test), case_bit_test_cmp); | |
2114 | ||
4845b383 KH |
2115 | index_expr = fold_build2 (MINUS_EXPR, index_type, |
2116 | fold_convert (index_type, index_expr), | |
2117 | fold_convert (index_type, minval)); | |
84217346 | 2118 | index = expand_normal (index_expr); |
9bb231fd RS |
2119 | do_pending_stack_adjust (); |
2120 | ||
2121 | mode = TYPE_MODE (index_type); | |
84217346 | 2122 | expr = expand_normal (range); |
b7814a18 RG |
2123 | if (default_label) |
2124 | emit_cmp_and_jump_insns (index, expr, GTU, NULL_RTX, mode, 1, | |
2125 | default_label); | |
9bb231fd RS |
2126 | |
2127 | index = convert_to_mode (word_mode, index, 0); | |
2128 | index = expand_binop (word_mode, ashl_optab, const1_rtx, | |
2129 | index, NULL_RTX, 1, OPTAB_WIDEN); | |
2130 | ||
2131 | for (i = 0; i < count; i++) | |
2132 | { | |
2133 | expr = immed_double_const (test[i].lo, test[i].hi, word_mode); | |
2134 | expr = expand_binop (word_mode, and_optab, index, expr, | |
2135 | NULL_RTX, 1, OPTAB_WIDEN); | |
2136 | emit_cmp_and_jump_insns (expr, const0_rtx, NE, NULL_RTX, | |
2137 | word_mode, 1, test[i].label); | |
2138 | } | |
2139 | ||
b7814a18 RG |
2140 | if (default_label) |
2141 | emit_jump (default_label); | |
9bb231fd | 2142 | } |
ad82abb8 | 2143 | |
41cbdcd0 KH |
2144 | #ifndef HAVE_casesi |
2145 | #define HAVE_casesi 0 | |
2146 | #endif | |
2147 | ||
2148 | #ifndef HAVE_tablejump | |
2149 | #define HAVE_tablejump 0 | |
2150 | #endif | |
2151 | ||
3feaea00 | 2152 | /* Terminate a case (Pascal/Ada) or switch (C) statement |
9ab0ddd7 | 2153 | in which ORIG_INDEX is the expression to be tested. |
6f9fdf4d JJ |
2154 | If ORIG_TYPE is not NULL, it is the original ORIG_INDEX |
2155 | type as given in the source before any compiler conversions. | |
28d81abb RK |
2156 | Generate the code to test it and jump to the right place. */ |
2157 | ||
2158 | void | |
7efcb746 | 2159 | expand_case (tree exp) |
28d81abb | 2160 | { |
9fb60a0d | 2161 | tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE; |
28d81abb | 2162 | rtx default_label = 0; |
4cfa46c8 | 2163 | struct case_node *n; |
9bb231fd | 2164 | unsigned int count, uniq; |
28d81abb | 2165 | rtx index; |
ca695ac9 | 2166 | rtx table_label; |
28d81abb RK |
2167 | int ncases; |
2168 | rtx *labelvec; | |
a38e7aa5 | 2169 | int i; |
9bb231fd | 2170 | rtx before_case, end, lab; |
ca695ac9 | 2171 | |
7efcb746 PB |
2172 | tree vec = SWITCH_LABELS (exp); |
2173 | tree orig_type = TREE_TYPE (exp); | |
2174 | tree index_expr = SWITCH_COND (exp); | |
2175 | tree index_type = TREE_TYPE (index_expr); | |
2176 | int unsignedp = TYPE_UNSIGNED (index_type); | |
2177 | ||
2178 | /* The insn after which the case dispatch should finally | |
2179 | be emitted. Zero for a dummy. */ | |
2180 | rtx start; | |
2181 | ||
2182 | /* A list of case labels; it is first built as a list and it may then | |
2183 | be rearranged into a nearly balanced binary tree. */ | |
2184 | struct case_node *case_list = 0; | |
2185 | ||
2186 | /* Label to jump to if no case matches. */ | |
b7814a18 | 2187 | tree default_label_decl = NULL_TREE; |
7efcb746 | 2188 | |
6ac1b3a4 LB |
2189 | alloc_pool case_node_pool = create_alloc_pool ("struct case_node pool", |
2190 | sizeof (struct case_node), | |
2191 | 100); | |
2192 | ||
7efcb746 PB |
2193 | /* The switch body is lowered in gimplify.c, we should never have |
2194 | switches with a non-NULL SWITCH_BODY here. */ | |
41374e13 NS |
2195 | gcc_assert (!SWITCH_BODY (exp)); |
2196 | gcc_assert (SWITCH_LABELS (exp)); | |
03c03770 | 2197 | |
28d81abb RK |
2198 | do_pending_stack_adjust (); |
2199 | ||
2200 | /* An ERROR_MARK occurs for various reasons including invalid data type. */ | |
1b0cb6fc | 2201 | if (index_type != error_mark_node) |
28d81abb | 2202 | { |
4e0148df | 2203 | tree elt; |
4cfa46c8 | 2204 | bitmap label_bitmap; |
b7814a18 | 2205 | int vl = TREE_VEC_LENGTH (vec); |
eb172681 | 2206 | |
5100d114 KH |
2207 | /* cleanup_tree_cfg removes all SWITCH_EXPR with their index |
2208 | expressions being INTEGER_CST. */ | |
2209 | gcc_assert (TREE_CODE (index_expr) != INTEGER_CST); | |
2210 | ||
b7814a18 RG |
2211 | /* The default case, if ever taken, is at the end of TREE_VEC. */ |
2212 | elt = TREE_VEC_ELT (vec, vl - 1); | |
2213 | if (!CASE_LOW (elt) && !CASE_HIGH (elt)) | |
2214 | { | |
2215 | default_label_decl = CASE_LABEL (elt); | |
2216 | --vl; | |
2217 | } | |
4e0148df | 2218 | |
b7814a18 | 2219 | for (i = vl - 1; i >= 0; --i) |
4e0148df | 2220 | { |
3feaea00 | 2221 | tree low, high; |
4e0148df | 2222 | elt = TREE_VEC_ELT (vec, i); |
3feaea00 EB |
2223 | |
2224 | low = CASE_LOW (elt); | |
2225 | gcc_assert (low); | |
2226 | high = CASE_HIGH (elt); | |
2227 | ||
2228 | /* Discard empty ranges. */ | |
288bd0d7 | 2229 | if (high && tree_int_cst_lt (high, low)) |
3feaea00 EB |
2230 | continue; |
2231 | ||
2232 | case_list = add_case_node (case_list, index_type, low, high, | |
6ac1b3a4 | 2233 | CASE_LABEL (elt), case_node_pool); |
eb172681 RS |
2234 | } |
2235 | ||
2236 | ||
ede497cf | 2237 | before_case = start = get_last_insn (); |
b7814a18 RG |
2238 | if (default_label_decl) |
2239 | default_label = label_rtx (default_label_decl); | |
28d81abb | 2240 | |
5cfffc4e | 2241 | /* Get upper and lower bounds of case values. */ |
28d81abb | 2242 | |
9bb231fd | 2243 | uniq = 0; |
28d81abb | 2244 | count = 0; |
8bdbfff5 | 2245 | label_bitmap = BITMAP_ALLOC (NULL); |
7efcb746 | 2246 | for (n = case_list; n; n = n->right) |
28d81abb | 2247 | { |
28d81abb RK |
2248 | /* Count the elements and track the largest and smallest |
2249 | of them (treating them as signed even if they are not). */ | |
2250 | if (count++ == 0) | |
2251 | { | |
2252 | minval = n->low; | |
2253 | maxval = n->high; | |
2254 | } | |
2255 | else | |
2256 | { | |
288bd0d7 | 2257 | if (tree_int_cst_lt (n->low, minval)) |
28d81abb | 2258 | minval = n->low; |
288bd0d7 | 2259 | if (tree_int_cst_lt (maxval, n->high)) |
28d81abb RK |
2260 | maxval = n->high; |
2261 | } | |
2262 | /* A range counts double, since it requires two compares. */ | |
2263 | if (! tree_int_cst_equal (n->low, n->high)) | |
2264 | count++; | |
9bb231fd | 2265 | |
4cfa46c8 JL |
2266 | /* If we have not seen this label yet, then increase the |
2267 | number of unique case node targets seen. */ | |
9bb231fd | 2268 | lab = label_rtx (n->code_label); |
4cfa46c8 JL |
2269 | if (!bitmap_bit_p (label_bitmap, CODE_LABEL_NUMBER (lab))) |
2270 | { | |
2271 | bitmap_set_bit (label_bitmap, CODE_LABEL_NUMBER (lab)); | |
2272 | uniq++; | |
2273 | } | |
28d81abb RK |
2274 | } |
2275 | ||
8bdbfff5 | 2276 | BITMAP_FREE (label_bitmap); |
4cfa46c8 | 2277 | |
5372d088 | 2278 | /* cleanup_tree_cfg removes all SWITCH_EXPR with a single |
2aabee29 AO |
2279 | destination, such as one with a default case only. However, |
2280 | it doesn't remove cases that are out of range for the switch | |
2281 | type, so we may still get a zero here. */ | |
2282 | if (count == 0) | |
2283 | { | |
b7814a18 RG |
2284 | if (default_label) |
2285 | emit_jump (default_label); | |
6ac1b3a4 | 2286 | free_alloc_pool (case_node_pool); |
2aabee29 AO |
2287 | return; |
2288 | } | |
28d81abb | 2289 | |
5372d088 | 2290 | /* Compute span of values. */ |
4845b383 | 2291 | range = fold_build2 (MINUS_EXPR, index_type, maxval, minval); |
3474db0e | 2292 | |
9bb231fd RS |
2293 | /* Try implementing this switch statement by a short sequence of |
2294 | bit-wise comparisons. However, we let the binary-tree case | |
2295 | below handle constant index expressions. */ | |
5372d088 KH |
2296 | if (CASE_USE_BIT_TESTS |
2297 | && ! TREE_CONSTANT (index_expr) | |
2298 | && compare_tree_int (range, GET_MODE_BITSIZE (word_mode)) < 0 | |
2299 | && compare_tree_int (range, 0) > 0 | |
2300 | && lshift_cheap_p () | |
2301 | && ((uniq == 1 && count >= 3) | |
2302 | || (uniq == 2 && count >= 5) | |
2303 | || (uniq == 3 && count >= 6))) | |
9bb231fd RS |
2304 | { |
2305 | /* Optimize the case where all the case values fit in a | |
2306 | word without having to subtract MINVAL. In this case, | |
2307 | we can optimize away the subtraction. */ | |
2308 | if (compare_tree_int (minval, 0) > 0 | |
2309 | && compare_tree_int (maxval, GET_MODE_BITSIZE (word_mode)) < 0) | |
2310 | { | |
3bedcc89 | 2311 | minval = build_int_cst (index_type, 0); |
9bb231fd RS |
2312 | range = maxval; |
2313 | } | |
2314 | emit_case_bit_tests (index_type, index_expr, minval, range, | |
7efcb746 | 2315 | case_list, default_label); |
9bb231fd RS |
2316 | } |
2317 | ||
28d81abb RK |
2318 | /* If range of values is much bigger than number of values, |
2319 | make a sequence of conditional branches instead of a dispatch. | |
2320 | If the switch-index is a constant, do it this way | |
2321 | because we can optimize it. */ | |
4f73c5dd | 2322 | |
ad82abb8 | 2323 | else if (count < case_values_threshold () |
9e4b13a7 | 2324 | || compare_tree_int (range, |
efd8f750 | 2325 | (optimize_insn_for_size_p () ? 3 : 10) * count) > 0 |
f0c988c8 BS |
2326 | /* RANGE may be signed, and really large ranges will show up |
2327 | as negative numbers. */ | |
2328 | || compare_tree_int (range, 0) < 0 | |
3f6fe18e RK |
2329 | #ifndef ASM_OUTPUT_ADDR_DIFF_ELT |
2330 | || flag_pic | |
2331 | #endif | |
82c0180d | 2332 | || !flag_jump_tables |
41cbdcd0 KH |
2333 | || TREE_CONSTANT (index_expr) |
2334 | /* If neither casesi or tablejump is available, we can | |
2335 | only go this way. */ | |
2336 | || (!HAVE_casesi && !HAVE_tablejump)) | |
28d81abb | 2337 | { |
84217346 | 2338 | index = expand_normal (index_expr); |
28d81abb RK |
2339 | |
2340 | /* If the index is a short or char that we do not have | |
2341 | an insn to handle comparisons directly, convert it to | |
2342 | a full integer now, rather than letting each comparison | |
2343 | generate the conversion. */ | |
2344 | ||
2345 | if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT | |
ef89d648 | 2346 | && ! have_insn_for (COMPARE, GET_MODE (index))) |
28d81abb RK |
2347 | { |
2348 | enum machine_mode wider_mode; | |
2349 | for (wider_mode = GET_MODE (index); wider_mode != VOIDmode; | |
2350 | wider_mode = GET_MODE_WIDER_MODE (wider_mode)) | |
ef89d648 | 2351 | if (have_insn_for (COMPARE, wider_mode)) |
28d81abb RK |
2352 | { |
2353 | index = convert_to_mode (wider_mode, index, unsignedp); | |
2354 | break; | |
2355 | } | |
2356 | } | |
2357 | ||
28d81abb RK |
2358 | do_pending_stack_adjust (); |
2359 | ||
3c0cb5de | 2360 | if (MEM_P (index)) |
28d81abb | 2361 | index = copy_to_reg (index); |
28d81abb | 2362 | |
b2c5a1e9 KH |
2363 | /* We generate a binary decision tree to select the |
2364 | appropriate target code. This is done as follows: | |
5100d114 KH |
2365 | |
2366 | The list of cases is rearranged into a binary tree, | |
2367 | nearly optimal assuming equal probability for each case. | |
2368 | ||
2369 | The tree is transformed into RTL, eliminating | |
2370 | redundant test conditions at the same time. | |
2371 | ||
2372 | If program flow could reach the end of the | |
2373 | decision tree an unconditional jump to the | |
2374 | default code is emitted. */ | |
2375 | ||
2376 | use_cost_table | |
2377 | = (TREE_CODE (orig_type) != ENUMERAL_TYPE | |
2378 | && estimate_case_costs (case_list)); | |
2379 | balance_case_nodes (&case_list, NULL); | |
2380 | emit_case_nodes (index, case_list, default_label, index_type); | |
b7814a18 RG |
2381 | if (default_label) |
2382 | emit_jump (default_label); | |
28d81abb RK |
2383 | } |
2384 | else | |
2385 | { | |
55187c8a | 2386 | rtx fallback_label = label_rtx (case_list->code_label); |
100e3acb | 2387 | table_label = gen_label_rtx (); |
ad82abb8 | 2388 | if (! try_casesi (index_type, index_expr, minval, range, |
55187c8a | 2389 | table_label, default_label, fallback_label)) |
28d81abb | 2390 | { |
41374e13 | 2391 | bool ok; |
1ff37128 | 2392 | |
786de7eb | 2393 | /* Index jumptables from zero for suitable values of |
1ff37128 | 2394 | minval to avoid a subtraction. */ |
efd8f750 | 2395 | if (optimize_insn_for_speed_p () |
786de7eb KH |
2396 | && compare_tree_int (minval, 0) > 0 |
2397 | && compare_tree_int (minval, 3) < 0) | |
2398 | { | |
3bedcc89 | 2399 | minval = build_int_cst (index_type, 0); |
786de7eb KH |
2400 | range = maxval; |
2401 | } | |
1ff37128 | 2402 | |
41374e13 NS |
2403 | ok = try_tablejump (index_type, index_expr, minval, range, |
2404 | table_label, default_label); | |
2405 | gcc_assert (ok); | |
28d81abb | 2406 | } |
786de7eb | 2407 | |
28d81abb RK |
2408 | /* Get table of labels to jump to, in order of case index. */ |
2409 | ||
1ff37128 | 2410 | ncases = tree_low_cst (range, 0) + 1; |
1634b18f | 2411 | labelvec = XALLOCAVEC (rtx, ncases); |
703ad42b | 2412 | memset (labelvec, 0, ncases * sizeof (rtx)); |
28d81abb | 2413 | |
7efcb746 | 2414 | for (n = case_list; n; n = n->right) |
28d81abb | 2415 | { |
2d9d49e4 OH |
2416 | /* Compute the low and high bounds relative to the minimum |
2417 | value since that should fit in a HOST_WIDE_INT while the | |
2418 | actual values may not. */ | |
2419 | HOST_WIDE_INT i_low | |
4845b383 KH |
2420 | = tree_low_cst (fold_build2 (MINUS_EXPR, index_type, |
2421 | n->low, minval), 1); | |
2d9d49e4 | 2422 | HOST_WIDE_INT i_high |
4845b383 KH |
2423 | = tree_low_cst (fold_build2 (MINUS_EXPR, index_type, |
2424 | n->high, minval), 1); | |
2d9d49e4 OH |
2425 | HOST_WIDE_INT i; |
2426 | ||
2427 | for (i = i_low; i <= i_high; i ++) | |
2428 | labelvec[i] | |
2429 | = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label)); | |
28d81abb RK |
2430 | } |
2431 | ||
55187c8a RG |
2432 | /* Fill in the gaps with the default. We may have gaps at |
2433 | the beginning if we tried to avoid the minval subtraction, | |
2434 | so substitute some label even if the default label was | |
2435 | deemed unreachable. */ | |
2436 | if (!default_label) | |
2437 | default_label = fallback_label; | |
2438 | for (i = 0; i < ncases; i++) | |
2439 | if (labelvec[i] == 0) | |
2440 | labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label); | |
28d81abb | 2441 | |
f9da5064 | 2442 | /* Output the table. */ |
28d81abb RK |
2443 | emit_label (table_label); |
2444 | ||
18543a22 | 2445 | if (CASE_VECTOR_PC_RELATIVE || flag_pic) |
38a448ca RH |
2446 | emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE, |
2447 | gen_rtx_LABEL_REF (Pmode, table_label), | |
33f7f353 | 2448 | gen_rtvec_v (ncases, labelvec), |
4381f7c2 | 2449 | const0_rtx, const0_rtx)); |
28d81abb | 2450 | else |
38a448ca RH |
2451 | emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE, |
2452 | gen_rtvec_v (ncases, labelvec))); | |
28d81abb | 2453 | |
6be85b25 | 2454 | /* Record no drop-through after the table. */ |
28d81abb | 2455 | emit_barrier (); |
28d81abb RK |
2456 | } |
2457 | ||
2270623a JM |
2458 | before_case = NEXT_INSN (before_case); |
2459 | end = get_last_insn (); | |
7efcb746 | 2460 | reorder_insns (before_case, end, start); |
28d81abb | 2461 | } |
1b0cb6fc | 2462 | |
28d81abb | 2463 | free_temp_slots (); |
6ac1b3a4 | 2464 | free_alloc_pool (case_node_pool); |
28d81abb RK |
2465 | } |
2466 | ||
feb04780 | 2467 | /* Generate code to jump to LABEL if OP0 and OP1 are equal in mode MODE. */ |
28d81abb RK |
2468 | |
2469 | static void | |
feb04780 RS |
2470 | do_jump_if_equal (enum machine_mode mode, rtx op0, rtx op1, rtx label, |
2471 | int unsignedp) | |
28d81abb | 2472 | { |
feb04780 RS |
2473 | do_compare_rtx_and_jump (op0, op1, EQ, unsignedp, mode, |
2474 | NULL_RTX, NULL_RTX, label); | |
28d81abb RK |
2475 | } |
2476 | \f | |
2477 | /* Not all case values are encountered equally. This function | |
2478 | uses a heuristic to weight case labels, in cases where that | |
2479 | looks like a reasonable thing to do. | |
2480 | ||
2481 | Right now, all we try to guess is text, and we establish the | |
2482 | following weights: | |
2483 | ||
2484 | chars above space: 16 | |
2485 | digits: 16 | |
2486 | default: 12 | |
2487 | space, punct: 8 | |
2488 | tab: 4 | |
2489 | newline: 2 | |
2490 | other "\" chars: 1 | |
2491 | remaining chars: 0 | |
2492 | ||
2493 | If we find any cases in the switch that are not either -1 or in the range | |
2494 | of valid ASCII characters, or are control characters other than those | |
2495 | commonly used with "\", don't treat this switch scanning text. | |
2496 | ||
2497 | Return 1 if these nodes are suitable for cost estimation, otherwise | |
2498 | return 0. */ | |
2499 | ||
2500 | static int | |
46c5ad27 | 2501 | estimate_case_costs (case_node_ptr node) |
28d81abb | 2502 | { |
f2d1f0ba | 2503 | tree min_ascii = integer_minus_one_node; |
aeba6c28 | 2504 | tree max_ascii = build_int_cst (TREE_TYPE (node->high), 127); |
28d81abb RK |
2505 | case_node_ptr n; |
2506 | int i; | |
2507 | ||
2508 | /* If we haven't already made the cost table, make it now. Note that the | |
2509 | lower bound of the table is -1, not zero. */ | |
2510 | ||
2a2137c4 | 2511 | if (! cost_table_initialized) |
28d81abb | 2512 | { |
2a2137c4 | 2513 | cost_table_initialized = 1; |
28d81abb RK |
2514 | |
2515 | for (i = 0; i < 128; i++) | |
2516 | { | |
e9a780ec | 2517 | if (ISALNUM (i)) |
2a2137c4 | 2518 | COST_TABLE (i) = 16; |
e9a780ec | 2519 | else if (ISPUNCT (i)) |
2a2137c4 | 2520 | COST_TABLE (i) = 8; |
e9a780ec | 2521 | else if (ISCNTRL (i)) |
2a2137c4 | 2522 | COST_TABLE (i) = -1; |
28d81abb RK |
2523 | } |
2524 | ||
2a2137c4 RH |
2525 | COST_TABLE (' ') = 8; |
2526 | COST_TABLE ('\t') = 4; | |
2527 | COST_TABLE ('\0') = 4; | |
2528 | COST_TABLE ('\n') = 2; | |
2529 | COST_TABLE ('\f') = 1; | |
2530 | COST_TABLE ('\v') = 1; | |
2531 | COST_TABLE ('\b') = 1; | |
28d81abb RK |
2532 | } |
2533 | ||
2534 | /* See if all the case expressions look like text. It is text if the | |
2535 | constant is >= -1 and the highest constant is <= 127. Do all comparisons | |
2536 | as signed arithmetic since we don't want to ever access cost_table with a | |
2537 | value less than -1. Also check that none of the constants in a range | |
2538 | are strange control characters. */ | |
2539 | ||
2540 | for (n = node; n; n = n->right) | |
2541 | { | |
288bd0d7 RG |
2542 | if (tree_int_cst_lt (n->low, min_ascii) |
2543 | || tree_int_cst_lt (max_ascii, n->high)) | |
28d81abb RK |
2544 | return 0; |
2545 | ||
05bccae2 RK |
2546 | for (i = (HOST_WIDE_INT) TREE_INT_CST_LOW (n->low); |
2547 | i <= (HOST_WIDE_INT) TREE_INT_CST_LOW (n->high); i++) | |
2a2137c4 | 2548 | if (COST_TABLE (i) < 0) |
28d81abb RK |
2549 | return 0; |
2550 | } | |
2551 | ||
2552 | /* All interesting values are within the range of interesting | |
2553 | ASCII characters. */ | |
2554 | return 1; | |
2555 | } | |
2556 | ||
28d81abb RK |
2557 | /* Take an ordered list of case nodes |
2558 | and transform them into a near optimal binary tree, | |
6dc42e49 | 2559 | on the assumption that any target code selection value is as |
28d81abb RK |
2560 | likely as any other. |
2561 | ||
2562 | The transformation is performed by splitting the ordered | |
2563 | list into two equal sections plus a pivot. The parts are | |
2564 | then attached to the pivot as left and right branches. Each | |
38e01259 | 2565 | branch is then transformed recursively. */ |
28d81abb RK |
2566 | |
2567 | static void | |
46c5ad27 | 2568 | balance_case_nodes (case_node_ptr *head, case_node_ptr parent) |
28d81abb | 2569 | { |
b3694847 | 2570 | case_node_ptr np; |
28d81abb RK |
2571 | |
2572 | np = *head; | |
2573 | if (np) | |
2574 | { | |
2575 | int cost = 0; | |
2576 | int i = 0; | |
2577 | int ranges = 0; | |
b3694847 | 2578 | case_node_ptr *npp; |
28d81abb RK |
2579 | case_node_ptr left; |
2580 | ||
2581 | /* Count the number of entries on branch. Also count the ranges. */ | |
2582 | ||
2583 | while (np) | |
2584 | { | |
2585 | if (!tree_int_cst_equal (np->low, np->high)) | |
2586 | { | |
2587 | ranges++; | |
2588 | if (use_cost_table) | |
2a2137c4 | 2589 | cost += COST_TABLE (TREE_INT_CST_LOW (np->high)); |
28d81abb RK |
2590 | } |
2591 | ||
2592 | if (use_cost_table) | |
2a2137c4 | 2593 | cost += COST_TABLE (TREE_INT_CST_LOW (np->low)); |
28d81abb RK |
2594 | |
2595 | i++; | |
2596 | np = np->right; | |
2597 | } | |
2598 | ||
2599 | if (i > 2) | |
2600 | { | |
2601 | /* Split this list if it is long enough for that to help. */ | |
2602 | npp = head; | |
2603 | left = *npp; | |
2604 | if (use_cost_table) | |
2605 | { | |
2606 | /* Find the place in the list that bisects the list's total cost, | |
2607 | Here I gets half the total cost. */ | |
2608 | int n_moved = 0; | |
2609 | i = (cost + 1) / 2; | |
2610 | while (1) | |
2611 | { | |
2612 | /* Skip nodes while their cost does not reach that amount. */ | |
2613 | if (!tree_int_cst_equal ((*npp)->low, (*npp)->high)) | |
2a2137c4 RH |
2614 | i -= COST_TABLE (TREE_INT_CST_LOW ((*npp)->high)); |
2615 | i -= COST_TABLE (TREE_INT_CST_LOW ((*npp)->low)); | |
28d81abb RK |
2616 | if (i <= 0) |
2617 | break; | |
2618 | npp = &(*npp)->right; | |
2619 | n_moved += 1; | |
2620 | } | |
2621 | if (n_moved == 0) | |
2622 | { | |
2623 | /* Leave this branch lopsided, but optimize left-hand | |
2624 | side and fill in `parent' fields for right-hand side. */ | |
2625 | np = *head; | |
2626 | np->parent = parent; | |
2627 | balance_case_nodes (&np->left, np); | |
2628 | for (; np->right; np = np->right) | |
2629 | np->right->parent = np; | |
2630 | return; | |
2631 | } | |
2632 | } | |
2633 | /* If there are just three nodes, split at the middle one. */ | |
2634 | else if (i == 3) | |
2635 | npp = &(*npp)->right; | |
2636 | else | |
2637 | { | |
2638 | /* Find the place in the list that bisects the list's total cost, | |
2639 | where ranges count as 2. | |
2640 | Here I gets half the total cost. */ | |
2641 | i = (i + ranges + 1) / 2; | |
2642 | while (1) | |
2643 | { | |
2644 | /* Skip nodes while their cost does not reach that amount. */ | |
2645 | if (!tree_int_cst_equal ((*npp)->low, (*npp)->high)) | |
2646 | i--; | |
2647 | i--; | |
2648 | if (i <= 0) | |
2649 | break; | |
2650 | npp = &(*npp)->right; | |
2651 | } | |
2652 | } | |
2653 | *head = np = *npp; | |
2654 | *npp = 0; | |
2655 | np->parent = parent; | |
2656 | np->left = left; | |
2657 | ||
2658 | /* Optimize each of the two split parts. */ | |
2659 | balance_case_nodes (&np->left, np); | |
2660 | balance_case_nodes (&np->right, np); | |
2661 | } | |
2662 | else | |
2663 | { | |
2664 | /* Else leave this branch as one level, | |
2665 | but fill in `parent' fields. */ | |
2666 | np = *head; | |
2667 | np->parent = parent; | |
2668 | for (; np->right; np = np->right) | |
2669 | np->right->parent = np; | |
2670 | } | |
2671 | } | |
2672 | } | |
2673 | \f | |
2674 | /* Search the parent sections of the case node tree | |
2675 | to see if a test for the lower bound of NODE would be redundant. | |
2676 | INDEX_TYPE is the type of the index expression. | |
2677 | ||
2678 | The instructions to generate the case decision tree are | |
2679 | output in the same order as nodes are processed so it is | |
2680 | known that if a parent node checks the range of the current | |
2681 | node minus one that the current node is bounded at its lower | |
2682 | span. Thus the test would be redundant. */ | |
2683 | ||
2684 | static int | |
46c5ad27 | 2685 | node_has_low_bound (case_node_ptr node, tree index_type) |
28d81abb RK |
2686 | { |
2687 | tree low_minus_one; | |
2688 | case_node_ptr pnode; | |
2689 | ||
2690 | /* If the lower bound of this node is the lowest value in the index type, | |
2691 | we need not test it. */ | |
2692 | ||
2693 | if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type))) | |
2694 | return 1; | |
2695 | ||
2696 | /* If this node has a left branch, the value at the left must be less | |
2697 | than that at this node, so it cannot be bounded at the bottom and | |
2698 | we need not bother testing any further. */ | |
2699 | ||
2700 | if (node->left) | |
2701 | return 0; | |
2702 | ||
4845b383 | 2703 | low_minus_one = fold_build2 (MINUS_EXPR, TREE_TYPE (node->low), |
3bedcc89 RG |
2704 | node->low, |
2705 | build_int_cst (TREE_TYPE (node->low), 1)); | |
28d81abb RK |
2706 | |
2707 | /* If the subtraction above overflowed, we can't verify anything. | |
2708 | Otherwise, look for a parent that tests our value - 1. */ | |
2709 | ||
2710 | if (! tree_int_cst_lt (low_minus_one, node->low)) | |
2711 | return 0; | |
2712 | ||
2713 | for (pnode = node->parent; pnode; pnode = pnode->parent) | |
2714 | if (tree_int_cst_equal (low_minus_one, pnode->high)) | |
2715 | return 1; | |
2716 | ||
2717 | return 0; | |
2718 | } | |
2719 | ||
2720 | /* Search the parent sections of the case node tree | |
2721 | to see if a test for the upper bound of NODE would be redundant. | |
2722 | INDEX_TYPE is the type of the index expression. | |
2723 | ||
2724 | The instructions to generate the case decision tree are | |
2725 | output in the same order as nodes are processed so it is | |
2726 | known that if a parent node checks the range of the current | |
2727 | node plus one that the current node is bounded at its upper | |
2728 | span. Thus the test would be redundant. */ | |
2729 | ||
2730 | static int | |
46c5ad27 | 2731 | node_has_high_bound (case_node_ptr node, tree index_type) |
28d81abb RK |
2732 | { |
2733 | tree high_plus_one; | |
2734 | case_node_ptr pnode; | |
2735 | ||
e1ee5cdc RH |
2736 | /* If there is no upper bound, obviously no test is needed. */ |
2737 | ||
2738 | if (TYPE_MAX_VALUE (index_type) == NULL) | |
2739 | return 1; | |
2740 | ||
28d81abb RK |
2741 | /* If the upper bound of this node is the highest value in the type |
2742 | of the index expression, we need not test against it. */ | |
2743 | ||
2744 | if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type))) | |
2745 | return 1; | |
2746 | ||
2747 | /* If this node has a right branch, the value at the right must be greater | |
2748 | than that at this node, so it cannot be bounded at the top and | |
2749 | we need not bother testing any further. */ | |
2750 | ||
2751 | if (node->right) | |
2752 | return 0; | |
2753 | ||
4845b383 | 2754 | high_plus_one = fold_build2 (PLUS_EXPR, TREE_TYPE (node->high), |
3bedcc89 RG |
2755 | node->high, |
2756 | build_int_cst (TREE_TYPE (node->high), 1)); | |
28d81abb RK |
2757 | |
2758 | /* If the addition above overflowed, we can't verify anything. | |
2759 | Otherwise, look for a parent that tests our value + 1. */ | |
2760 | ||
2761 | if (! tree_int_cst_lt (node->high, high_plus_one)) | |
2762 | return 0; | |
2763 | ||
2764 | for (pnode = node->parent; pnode; pnode = pnode->parent) | |
2765 | if (tree_int_cst_equal (high_plus_one, pnode->low)) | |
2766 | return 1; | |
2767 | ||
2768 | return 0; | |
2769 | } | |
2770 | ||
2771 | /* Search the parent sections of the | |
2772 | case node tree to see if both tests for the upper and lower | |
2773 | bounds of NODE would be redundant. */ | |
2774 | ||
2775 | static int | |
46c5ad27 | 2776 | node_is_bounded (case_node_ptr node, tree index_type) |
28d81abb RK |
2777 | { |
2778 | return (node_has_low_bound (node, index_type) | |
2779 | && node_has_high_bound (node, index_type)); | |
2780 | } | |
28d81abb RK |
2781 | \f |
2782 | /* Emit step-by-step code to select a case for the value of INDEX. | |
2783 | The thus generated decision tree follows the form of the | |
2784 | case-node binary tree NODE, whose nodes represent test conditions. | |
2785 | INDEX_TYPE is the type of the index of the switch. | |
2786 | ||
2787 | Care is taken to prune redundant tests from the decision tree | |
2788 | by detecting any boundary conditions already checked by | |
2789 | emitted rtx. (See node_has_high_bound, node_has_low_bound | |
2790 | and node_is_bounded, above.) | |
2791 | ||
2792 | Where the test conditions can be shown to be redundant we emit | |
2793 | an unconditional jump to the target code. As a further | |
2794 | optimization, the subordinates of a tree node are examined to | |
2795 | check for bounded nodes. In this case conditional and/or | |
2796 | unconditional jumps as a result of the boundary check for the | |
2797 | current node are arranged to target the subordinates associated | |
38e01259 | 2798 | code for out of bound conditions on the current node. |
28d81abb | 2799 | |
f72aed24 | 2800 | We can assume that when control reaches the code generated here, |
28d81abb RK |
2801 | the index value has already been compared with the parents |
2802 | of this node, and determined to be on the same side of each parent | |
2803 | as this node is. Thus, if this node tests for the value 51, | |
2804 | and a parent tested for 52, we don't need to consider | |
2805 | the possibility of a value greater than 51. If another parent | |
2806 | tests for the value 50, then this node need not test anything. */ | |
2807 | ||
2808 | static void | |
46c5ad27 AJ |
2809 | emit_case_nodes (rtx index, case_node_ptr node, rtx default_label, |
2810 | tree index_type) | |
28d81abb RK |
2811 | { |
2812 | /* If INDEX has an unsigned type, we must make unsigned branches. */ | |
8df83eae | 2813 | int unsignedp = TYPE_UNSIGNED (index_type); |
28d81abb | 2814 | enum machine_mode mode = GET_MODE (index); |
69107307 | 2815 | enum machine_mode imode = TYPE_MODE (index_type); |
28d81abb | 2816 | |
f8318079 RS |
2817 | /* Handle indices detected as constant during RTL expansion. */ |
2818 | if (mode == VOIDmode) | |
2819 | mode = imode; | |
2820 | ||
28d81abb RK |
2821 | /* See if our parents have already tested everything for us. |
2822 | If they have, emit an unconditional jump for this node. */ | |
2823 | if (node_is_bounded (node, index_type)) | |
2824 | emit_jump (label_rtx (node->code_label)); | |
2825 | ||
2826 | else if (tree_int_cst_equal (node->low, node->high)) | |
2827 | { | |
2828 | /* Node is single valued. First see if the index expression matches | |
0f41302f | 2829 | this node and then check our children, if any. */ |
28d81abb | 2830 | |
feb04780 | 2831 | do_jump_if_equal (mode, index, |
69107307 | 2832 | convert_modes (mode, imode, |
84217346 | 2833 | expand_normal (node->low), |
69107307 | 2834 | unsignedp), |
28d81abb RK |
2835 | label_rtx (node->code_label), unsignedp); |
2836 | ||
2837 | if (node->right != 0 && node->left != 0) | |
2838 | { | |
2839 | /* This node has children on both sides. | |
2840 | Dispatch to one side or the other | |
2841 | by comparing the index value with this node's value. | |
2842 | If one subtree is bounded, check that one first, | |
2843 | so we can avoid real branches in the tree. */ | |
2844 | ||
2845 | if (node_is_bounded (node->right, index_type)) | |
2846 | { | |
4381f7c2 | 2847 | emit_cmp_and_jump_insns (index, |
69107307 AO |
2848 | convert_modes |
2849 | (mode, imode, | |
84217346 | 2850 | expand_normal (node->high), |
69107307 | 2851 | unsignedp), |
d43e0b7d | 2852 | GT, NULL_RTX, mode, unsignedp, |
4381f7c2 | 2853 | label_rtx (node->right->code_label)); |
28d81abb RK |
2854 | emit_case_nodes (index, node->left, default_label, index_type); |
2855 | } | |
2856 | ||
2857 | else if (node_is_bounded (node->left, index_type)) | |
2858 | { | |
4381f7c2 | 2859 | emit_cmp_and_jump_insns (index, |
69107307 AO |
2860 | convert_modes |
2861 | (mode, imode, | |
84217346 | 2862 | expand_normal (node->high), |
69107307 | 2863 | unsignedp), |
d43e0b7d | 2864 | LT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 2865 | label_rtx (node->left->code_label)); |
28d81abb RK |
2866 | emit_case_nodes (index, node->right, default_label, index_type); |
2867 | } | |
2868 | ||
43a21dfc KH |
2869 | /* If both children are single-valued cases with no |
2870 | children, finish up all the work. This way, we can save | |
2871 | one ordered comparison. */ | |
2872 | else if (tree_int_cst_equal (node->right->low, node->right->high) | |
2873 | && node->right->left == 0 | |
2874 | && node->right->right == 0 | |
2875 | && tree_int_cst_equal (node->left->low, node->left->high) | |
2876 | && node->left->left == 0 | |
2877 | && node->left->right == 0) | |
2878 | { | |
2879 | /* Neither node is bounded. First distinguish the two sides; | |
2880 | then emit the code for one side at a time. */ | |
2881 | ||
2882 | /* See if the value matches what the right hand side | |
2883 | wants. */ | |
feb04780 | 2884 | do_jump_if_equal (mode, index, |
43a21dfc | 2885 | convert_modes (mode, imode, |
84217346 | 2886 | expand_normal (node->right->low), |
43a21dfc KH |
2887 | unsignedp), |
2888 | label_rtx (node->right->code_label), | |
2889 | unsignedp); | |
2890 | ||
2891 | /* See if the value matches what the left hand side | |
2892 | wants. */ | |
feb04780 | 2893 | do_jump_if_equal (mode, index, |
43a21dfc | 2894 | convert_modes (mode, imode, |
84217346 | 2895 | expand_normal (node->left->low), |
43a21dfc KH |
2896 | unsignedp), |
2897 | label_rtx (node->left->code_label), | |
2898 | unsignedp); | |
2899 | } | |
2900 | ||
28d81abb RK |
2901 | else |
2902 | { | |
2903 | /* Neither node is bounded. First distinguish the two sides; | |
2904 | then emit the code for one side at a time. */ | |
2905 | ||
4381f7c2 | 2906 | tree test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE); |
28d81abb RK |
2907 | |
2908 | /* See if the value is on the right. */ | |
4381f7c2 | 2909 | emit_cmp_and_jump_insns (index, |
69107307 AO |
2910 | convert_modes |
2911 | (mode, imode, | |
84217346 | 2912 | expand_normal (node->high), |
69107307 | 2913 | unsignedp), |
d43e0b7d | 2914 | GT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 2915 | label_rtx (test_label)); |
28d81abb RK |
2916 | |
2917 | /* Value must be on the left. | |
2918 | Handle the left-hand subtree. */ | |
2919 | emit_case_nodes (index, node->left, default_label, index_type); | |
2920 | /* If left-hand subtree does nothing, | |
2921 | go to default. */ | |
b7814a18 RG |
2922 | if (default_label) |
2923 | emit_jump (default_label); | |
28d81abb RK |
2924 | |
2925 | /* Code branches here for the right-hand subtree. */ | |
2926 | expand_label (test_label); | |
2927 | emit_case_nodes (index, node->right, default_label, index_type); | |
2928 | } | |
2929 | } | |
2930 | ||
2931 | else if (node->right != 0 && node->left == 0) | |
2932 | { | |
adb35797 | 2933 | /* Here we have a right child but no left so we issue a conditional |
28d81abb RK |
2934 | branch to default and process the right child. |
2935 | ||
adb35797 KH |
2936 | Omit the conditional branch to default if the right child |
2937 | does not have any children and is single valued; it would | |
2938 | cost too much space to save so little time. */ | |
28d81abb | 2939 | |
de14fd73 | 2940 | if (node->right->right || node->right->left |
28d81abb RK |
2941 | || !tree_int_cst_equal (node->right->low, node->right->high)) |
2942 | { | |
2943 | if (!node_has_low_bound (node, index_type)) | |
2944 | { | |
4381f7c2 | 2945 | emit_cmp_and_jump_insns (index, |
69107307 AO |
2946 | convert_modes |
2947 | (mode, imode, | |
84217346 | 2948 | expand_normal (node->high), |
69107307 | 2949 | unsignedp), |
d43e0b7d | 2950 | LT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 2951 | default_label); |
28d81abb RK |
2952 | } |
2953 | ||
2954 | emit_case_nodes (index, node->right, default_label, index_type); | |
2955 | } | |
2956 | else | |
2957 | /* We cannot process node->right normally | |
2958 | since we haven't ruled out the numbers less than | |
2959 | this node's value. So handle node->right explicitly. */ | |
feb04780 | 2960 | do_jump_if_equal (mode, index, |
69107307 AO |
2961 | convert_modes |
2962 | (mode, imode, | |
84217346 | 2963 | expand_normal (node->right->low), |
69107307 | 2964 | unsignedp), |
28d81abb RK |
2965 | label_rtx (node->right->code_label), unsignedp); |
2966 | } | |
2967 | ||
2968 | else if (node->right == 0 && node->left != 0) | |
2969 | { | |
2970 | /* Just one subtree, on the left. */ | |
4381f7c2 | 2971 | if (node->left->left || node->left->right |
28d81abb RK |
2972 | || !tree_int_cst_equal (node->left->low, node->left->high)) |
2973 | { | |
2974 | if (!node_has_high_bound (node, index_type)) | |
2975 | { | |
69107307 AO |
2976 | emit_cmp_and_jump_insns (index, |
2977 | convert_modes | |
2978 | (mode, imode, | |
84217346 | 2979 | expand_normal (node->high), |
69107307 | 2980 | unsignedp), |
d43e0b7d | 2981 | GT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 2982 | default_label); |
28d81abb RK |
2983 | } |
2984 | ||
2985 | emit_case_nodes (index, node->left, default_label, index_type); | |
2986 | } | |
2987 | else | |
2988 | /* We cannot process node->left normally | |
2989 | since we haven't ruled out the numbers less than | |
2990 | this node's value. So handle node->left explicitly. */ | |
feb04780 | 2991 | do_jump_if_equal (mode, index, |
69107307 AO |
2992 | convert_modes |
2993 | (mode, imode, | |
84217346 | 2994 | expand_normal (node->left->low), |
69107307 | 2995 | unsignedp), |
28d81abb RK |
2996 | label_rtx (node->left->code_label), unsignedp); |
2997 | } | |
2998 | } | |
2999 | else | |
3000 | { | |
3001 | /* Node is a range. These cases are very similar to those for a single | |
3002 | value, except that we do not start by testing whether this node | |
3003 | is the one to branch to. */ | |
3004 | ||
3005 | if (node->right != 0 && node->left != 0) | |
3006 | { | |
3007 | /* Node has subtrees on both sides. | |
3008 | If the right-hand subtree is bounded, | |
3009 | test for it first, since we can go straight there. | |
3010 | Otherwise, we need to make a branch in the control structure, | |
3011 | then handle the two subtrees. */ | |
3012 | tree test_label = 0; | |
3013 | ||
28d81abb RK |
3014 | if (node_is_bounded (node->right, index_type)) |
3015 | /* Right hand node is fully bounded so we can eliminate any | |
3016 | testing and branch directly to the target code. */ | |
69107307 AO |
3017 | emit_cmp_and_jump_insns (index, |
3018 | convert_modes | |
3019 | (mode, imode, | |
84217346 | 3020 | expand_normal (node->high), |
69107307 | 3021 | unsignedp), |
d43e0b7d | 3022 | GT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3023 | label_rtx (node->right->code_label)); |
28d81abb RK |
3024 | else |
3025 | { | |
3026 | /* Right hand node requires testing. | |
3027 | Branch to a label where we will handle it later. */ | |
3028 | ||
3029 | test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE); | |
4381f7c2 | 3030 | emit_cmp_and_jump_insns (index, |
69107307 AO |
3031 | convert_modes |
3032 | (mode, imode, | |
84217346 | 3033 | expand_normal (node->high), |
69107307 | 3034 | unsignedp), |
d43e0b7d | 3035 | GT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3036 | label_rtx (test_label)); |
28d81abb RK |
3037 | } |
3038 | ||
3039 | /* Value belongs to this node or to the left-hand subtree. */ | |
3040 | ||
69107307 AO |
3041 | emit_cmp_and_jump_insns (index, |
3042 | convert_modes | |
3043 | (mode, imode, | |
84217346 | 3044 | expand_normal (node->low), |
69107307 | 3045 | unsignedp), |
d43e0b7d | 3046 | GE, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3047 | label_rtx (node->code_label)); |
28d81abb RK |
3048 | |
3049 | /* Handle the left-hand subtree. */ | |
3050 | emit_case_nodes (index, node->left, default_label, index_type); | |
3051 | ||
3052 | /* If right node had to be handled later, do that now. */ | |
3053 | ||
3054 | if (test_label) | |
3055 | { | |
3056 | /* If the left-hand subtree fell through, | |
3057 | don't let it fall into the right-hand subtree. */ | |
b7814a18 RG |
3058 | if (default_label) |
3059 | emit_jump (default_label); | |
28d81abb RK |
3060 | |
3061 | expand_label (test_label); | |
3062 | emit_case_nodes (index, node->right, default_label, index_type); | |
3063 | } | |
3064 | } | |
3065 | ||
3066 | else if (node->right != 0 && node->left == 0) | |
3067 | { | |
3068 | /* Deal with values to the left of this node, | |
3069 | if they are possible. */ | |
3070 | if (!node_has_low_bound (node, index_type)) | |
3071 | { | |
4381f7c2 | 3072 | emit_cmp_and_jump_insns (index, |
69107307 AO |
3073 | convert_modes |
3074 | (mode, imode, | |
84217346 | 3075 | expand_normal (node->low), |
69107307 | 3076 | unsignedp), |
d43e0b7d | 3077 | LT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3078 | default_label); |
28d81abb RK |
3079 | } |
3080 | ||
3081 | /* Value belongs to this node or to the right-hand subtree. */ | |
3082 | ||
69107307 AO |
3083 | emit_cmp_and_jump_insns (index, |
3084 | convert_modes | |
3085 | (mode, imode, | |
84217346 | 3086 | expand_normal (node->high), |
69107307 | 3087 | unsignedp), |
d43e0b7d | 3088 | LE, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3089 | label_rtx (node->code_label)); |
28d81abb RK |
3090 | |
3091 | emit_case_nodes (index, node->right, default_label, index_type); | |
3092 | } | |
3093 | ||
3094 | else if (node->right == 0 && node->left != 0) | |
3095 | { | |
3096 | /* Deal with values to the right of this node, | |
3097 | if they are possible. */ | |
3098 | if (!node_has_high_bound (node, index_type)) | |
3099 | { | |
4381f7c2 | 3100 | emit_cmp_and_jump_insns (index, |
69107307 AO |
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 | /* Value belongs to this node or to the left-hand subtree. */ | |
3110 | ||
4381f7c2 | 3111 | emit_cmp_and_jump_insns (index, |
69107307 AO |
3112 | convert_modes |
3113 | (mode, imode, | |
84217346 | 3114 | expand_normal (node->low), |
69107307 | 3115 | unsignedp), |
d43e0b7d | 3116 | GE, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3117 | label_rtx (node->code_label)); |
28d81abb RK |
3118 | |
3119 | emit_case_nodes (index, node->left, default_label, index_type); | |
3120 | } | |
3121 | ||
3122 | else | |
3123 | { | |
3124 | /* Node has no children so we check low and high bounds to remove | |
3125 | redundant tests. Only one of the bounds can exist, | |
3126 | since otherwise this node is bounded--a case tested already. */ | |
923cbdc3 JH |
3127 | int high_bound = node_has_high_bound (node, index_type); |
3128 | int low_bound = node_has_low_bound (node, index_type); | |
28d81abb | 3129 | |
923cbdc3 | 3130 | if (!high_bound && low_bound) |
28d81abb | 3131 | { |
4381f7c2 | 3132 | emit_cmp_and_jump_insns (index, |
69107307 AO |
3133 | convert_modes |
3134 | (mode, imode, | |
84217346 | 3135 | expand_normal (node->high), |
69107307 | 3136 | unsignedp), |
d43e0b7d | 3137 | GT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3138 | default_label); |
28d81abb RK |
3139 | } |
3140 | ||
923cbdc3 | 3141 | else if (!low_bound && high_bound) |
28d81abb | 3142 | { |
4381f7c2 | 3143 | emit_cmp_and_jump_insns (index, |
69107307 AO |
3144 | convert_modes |
3145 | (mode, imode, | |
84217346 | 3146 | expand_normal (node->low), |
69107307 | 3147 | unsignedp), |
d43e0b7d | 3148 | LT, NULL_RTX, mode, unsignedp, |
c5d5d461 | 3149 | default_label); |
28d81abb | 3150 | } |
923cbdc3 JH |
3151 | else if (!low_bound && !high_bound) |
3152 | { | |
9312aecc | 3153 | /* Widen LOW and HIGH to the same width as INDEX. */ |
ae2bcd98 | 3154 | tree type = lang_hooks.types.type_for_mode (mode, unsignedp); |
9312aecc JDA |
3155 | tree low = build1 (CONVERT_EXPR, type, node->low); |
3156 | tree high = build1 (CONVERT_EXPR, type, node->high); | |
ef89d648 | 3157 | rtx low_rtx, new_index, new_bound; |
9312aecc JDA |
3158 | |
3159 | /* Instead of doing two branches, emit one unsigned branch for | |
3160 | (index-low) > (high-low). */ | |
84217346 | 3161 | low_rtx = expand_expr (low, NULL_RTX, mode, EXPAND_NORMAL); |
ef89d648 ZW |
3162 | new_index = expand_simple_binop (mode, MINUS, index, low_rtx, |
3163 | NULL_RTX, unsignedp, | |
3164 | OPTAB_WIDEN); | |
4845b383 KH |
3165 | new_bound = expand_expr (fold_build2 (MINUS_EXPR, type, |
3166 | high, low), | |
84217346 | 3167 | NULL_RTX, mode, EXPAND_NORMAL); |
786de7eb | 3168 | |
9312aecc | 3169 | emit_cmp_and_jump_insns (new_index, new_bound, GT, NULL_RTX, |
d43e0b7d | 3170 | mode, 1, default_label); |
923cbdc3 | 3171 | } |
28d81abb RK |
3172 | |
3173 | emit_jump (label_rtx (node->code_label)); | |
3174 | } | |
3175 | } | |
3176 | } |