xref: /openbsd/gnu/gcc/gcc/integrate.c (revision 5af055cd)
1 /* Procedure integration for GCC.
2    Copyright (C) 1988, 1991, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
3    2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
4    Contributed by Michael Tiemann (tiemann@cygnus.com)
5 
6 This file is part of GCC.
7 
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 2, or (at your option) any later
11 version.
12 
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.
17 
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING.  If not, write to the Free
20 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
21 02110-1301, USA.  */
22 
23 #include "config.h"
24 #include "system.h"
25 #include "coretypes.h"
26 #include "tm.h"
27 
28 #include "rtl.h"
29 #include "tree.h"
30 #include "tm_p.h"
31 #include "regs.h"
32 #include "flags.h"
33 #include "debug.h"
34 #include "insn-config.h"
35 #include "expr.h"
36 #include "output.h"
37 #include "recog.h"
38 #include "integrate.h"
39 #include "real.h"
40 #include "except.h"
41 #include "function.h"
42 #include "toplev.h"
43 #include "intl.h"
44 #include "params.h"
45 #include "ggc.h"
46 #include "target.h"
47 #include "langhooks.h"
48 #include "tree-pass.h"
49 
50 /* Round to the next highest integer that meets the alignment.  */
51 #define CEIL_ROUND(VALUE,ALIGN)	(((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
52 
53 
54 /* Private type used by {get/has}_hard_reg_initial_val.  */
55 typedef struct initial_value_pair GTY(()) {
56   rtx hard_reg;
57   rtx pseudo;
58 } initial_value_pair;
59 typedef struct initial_value_struct GTY(()) {
60   int num_entries;
61   int max_entries;
62   initial_value_pair * GTY ((length ("%h.num_entries"))) entries;
63 } initial_value_struct;
64 
65 static void set_block_origin_self (tree);
66 static void set_block_abstract_flags (tree, int);
67 
68 
69 /* Return false if the function FNDECL cannot be inlined on account of its
70    attributes, true otherwise.  */
71 bool
72 function_attribute_inlinable_p (tree fndecl)
73 {
74   if (targetm.attribute_table)
75     {
76       tree a;
77 
78       for (a = DECL_ATTRIBUTES (fndecl); a; a = TREE_CHAIN (a))
79 	{
80 	  tree name = TREE_PURPOSE (a);
81 	  int i;
82 
83 	  for (i = 0; targetm.attribute_table[i].name != NULL; i++)
84 	    if (is_attribute_p (targetm.attribute_table[i].name, name))
85 	      return targetm.function_attribute_inlinable_p (fndecl);
86 	}
87     }
88 
89   return true;
90 }
91 
92 /* Given a pointer to some BLOCK node, if the BLOCK_ABSTRACT_ORIGIN for the
93    given BLOCK node is NULL, set the BLOCK_ABSTRACT_ORIGIN for the node so
94    that it points to the node itself, thus indicating that the node is its
95    own (abstract) origin.  Additionally, if the BLOCK_ABSTRACT_ORIGIN for
96    the given node is NULL, recursively descend the decl/block tree which
97    it is the root of, and for each other ..._DECL or BLOCK node contained
98    therein whose DECL_ABSTRACT_ORIGINs or BLOCK_ABSTRACT_ORIGINs are also
99    still NULL, set *their* DECL_ABSTRACT_ORIGIN or BLOCK_ABSTRACT_ORIGIN
100    values to point to themselves.  */
101 
102 static void
103 set_block_origin_self (tree stmt)
104 {
105   if (BLOCK_ABSTRACT_ORIGIN (stmt) == NULL_TREE)
106     {
107       BLOCK_ABSTRACT_ORIGIN (stmt) = stmt;
108 
109       {
110 	tree local_decl;
111 
112 	for (local_decl = BLOCK_VARS (stmt);
113 	     local_decl != NULL_TREE;
114 	     local_decl = TREE_CHAIN (local_decl))
115 	  set_decl_origin_self (local_decl);	/* Potential recursion.  */
116       }
117 
118       {
119 	tree subblock;
120 
121 	for (subblock = BLOCK_SUBBLOCKS (stmt);
122 	     subblock != NULL_TREE;
123 	     subblock = BLOCK_CHAIN (subblock))
124 	  set_block_origin_self (subblock);	/* Recurse.  */
125       }
126     }
127 }
128 
129 /* Given a pointer to some ..._DECL node, if the DECL_ABSTRACT_ORIGIN for
130    the given ..._DECL node is NULL, set the DECL_ABSTRACT_ORIGIN for the
131    node to so that it points to the node itself, thus indicating that the
132    node represents its own (abstract) origin.  Additionally, if the
133    DECL_ABSTRACT_ORIGIN for the given node is NULL, recursively descend
134    the decl/block tree of which the given node is the root of, and for
135    each other ..._DECL or BLOCK node contained therein whose
136    DECL_ABSTRACT_ORIGINs or BLOCK_ABSTRACT_ORIGINs are also still NULL,
137    set *their* DECL_ABSTRACT_ORIGIN or BLOCK_ABSTRACT_ORIGIN values to
138    point to themselves.  */
139 
140 void
141 set_decl_origin_self (tree decl)
142 {
143   if (DECL_ABSTRACT_ORIGIN (decl) == NULL_TREE)
144     {
145       DECL_ABSTRACT_ORIGIN (decl) = decl;
146       if (TREE_CODE (decl) == FUNCTION_DECL)
147 	{
148 	  tree arg;
149 
150 	  for (arg = DECL_ARGUMENTS (decl); arg; arg = TREE_CHAIN (arg))
151 	    DECL_ABSTRACT_ORIGIN (arg) = arg;
152 	  if (DECL_INITIAL (decl) != NULL_TREE
153 	      && DECL_INITIAL (decl) != error_mark_node)
154 	    set_block_origin_self (DECL_INITIAL (decl));
155 	}
156     }
157 }
158 
159 /* Given a pointer to some BLOCK node, and a boolean value to set the
160    "abstract" flags to, set that value into the BLOCK_ABSTRACT flag for
161    the given block, and for all local decls and all local sub-blocks
162    (recursively) which are contained therein.  */
163 
164 static void
165 set_block_abstract_flags (tree stmt, int setting)
166 {
167   tree local_decl;
168   tree subblock;
169 
170   BLOCK_ABSTRACT (stmt) = setting;
171 
172   for (local_decl = BLOCK_VARS (stmt);
173        local_decl != NULL_TREE;
174        local_decl = TREE_CHAIN (local_decl))
175     set_decl_abstract_flags (local_decl, setting);
176 
177   for (subblock = BLOCK_SUBBLOCKS (stmt);
178        subblock != NULL_TREE;
179        subblock = BLOCK_CHAIN (subblock))
180     set_block_abstract_flags (subblock, setting);
181 }
182 
183 /* Given a pointer to some ..._DECL node, and a boolean value to set the
184    "abstract" flags to, set that value into the DECL_ABSTRACT flag for the
185    given decl, and (in the case where the decl is a FUNCTION_DECL) also
186    set the abstract flags for all of the parameters, local vars, local
187    blocks and sub-blocks (recursively) to the same setting.  */
188 
189 void
190 set_decl_abstract_flags (tree decl, int setting)
191 {
192   DECL_ABSTRACT (decl) = setting;
193   if (TREE_CODE (decl) == FUNCTION_DECL)
194     {
195       tree arg;
196 
197       for (arg = DECL_ARGUMENTS (decl); arg; arg = TREE_CHAIN (arg))
198 	DECL_ABSTRACT (arg) = setting;
199       if (DECL_INITIAL (decl) != NULL_TREE
200 	  && DECL_INITIAL (decl) != error_mark_node)
201 	set_block_abstract_flags (DECL_INITIAL (decl), setting);
202     }
203 }
204 
205 /* Functions to keep track of the values hard regs had at the start of
206    the function.  */
207 
208 rtx
209 get_hard_reg_initial_reg (struct function *fun, rtx reg)
210 {
211   struct initial_value_struct *ivs = fun->hard_reg_initial_vals;
212   int i;
213 
214   if (ivs == 0)
215     return NULL_RTX;
216 
217   for (i = 0; i < ivs->num_entries; i++)
218     if (rtx_equal_p (ivs->entries[i].pseudo, reg))
219       return ivs->entries[i].hard_reg;
220 
221   return NULL_RTX;
222 }
223 
224 /* Make sure that there's a pseudo register of mode MODE that stores the
225    initial value of hard register REGNO.  Return an rtx for such a pseudo.  */
226 
227 rtx
228 get_hard_reg_initial_val (enum machine_mode mode, unsigned int regno)
229 {
230   struct initial_value_struct *ivs;
231   rtx rv;
232 
233   rv = has_hard_reg_initial_val (mode, regno);
234   if (rv)
235     return rv;
236 
237   ivs = cfun->hard_reg_initial_vals;
238   if (ivs == 0)
239     {
240       ivs = ggc_alloc (sizeof (initial_value_struct));
241       ivs->num_entries = 0;
242       ivs->max_entries = 5;
243       ivs->entries = ggc_alloc (5 * sizeof (initial_value_pair));
244       cfun->hard_reg_initial_vals = ivs;
245     }
246 
247   if (ivs->num_entries >= ivs->max_entries)
248     {
249       ivs->max_entries += 5;
250       ivs->entries = ggc_realloc (ivs->entries,
251 				  ivs->max_entries
252 				  * sizeof (initial_value_pair));
253     }
254 
255   ivs->entries[ivs->num_entries].hard_reg = gen_rtx_REG (mode, regno);
256   ivs->entries[ivs->num_entries].pseudo = gen_reg_rtx (mode);
257 
258   return ivs->entries[ivs->num_entries++].pseudo;
259 }
260 
261 /* See if get_hard_reg_initial_val has been used to create a pseudo
262    for the initial value of hard register REGNO in mode MODE.  Return
263    the associated pseudo if so, otherwise return NULL.  */
264 
265 rtx
266 has_hard_reg_initial_val (enum machine_mode mode, unsigned int regno)
267 {
268   struct initial_value_struct *ivs;
269   int i;
270 
271   ivs = cfun->hard_reg_initial_vals;
272   if (ivs != 0)
273     for (i = 0; i < ivs->num_entries; i++)
274       if (GET_MODE (ivs->entries[i].hard_reg) == mode
275 	  && REGNO (ivs->entries[i].hard_reg) == regno)
276 	return ivs->entries[i].pseudo;
277 
278   return NULL_RTX;
279 }
280 
281 unsigned int
282 emit_initial_value_sets (void)
283 {
284   struct initial_value_struct *ivs = cfun->hard_reg_initial_vals;
285   int i;
286   rtx seq;
287 
288   if (ivs == 0)
289     return 0;
290 
291   start_sequence ();
292   for (i = 0; i < ivs->num_entries; i++)
293     emit_move_insn (ivs->entries[i].pseudo, ivs->entries[i].hard_reg);
294   seq = get_insns ();
295   end_sequence ();
296 
297   emit_insn_at_entry (seq);
298   return 0;
299 }
300 
301 struct tree_opt_pass pass_initial_value_sets =
302 {
303   "initvals",                           /* name */
304   NULL,                                 /* gate */
305   emit_initial_value_sets,              /* execute */
306   NULL,                                 /* sub */
307   NULL,                                 /* next */
308   0,                                    /* static_pass_number */
309   0,                                    /* tv_id */
310   0,                                    /* properties_required */
311   0,                                    /* properties_provided */
312   0,                                    /* properties_destroyed */
313   0,                                    /* todo_flags_start */
314   TODO_dump_func,                       /* todo_flags_finish */
315   0                                     /* letter */
316 };
317 
318 /* If the backend knows where to allocate pseudos for hard
319    register initial values, register these allocations now.  */
320 void
321 allocate_initial_values (rtx *reg_equiv_memory_loc ATTRIBUTE_UNUSED)
322 {
323   if (targetm.allocate_initial_value)
324     {
325       struct initial_value_struct *ivs = cfun->hard_reg_initial_vals;
326       int i;
327 
328       if (ivs == 0)
329 	return;
330 
331       for (i = 0; i < ivs->num_entries; i++)
332 	{
333 	  int regno = REGNO (ivs->entries[i].pseudo);
334 	  rtx x = targetm.allocate_initial_value (ivs->entries[i].hard_reg);
335 
336 	  if (x && REG_N_SETS (REGNO (ivs->entries[i].pseudo)) <= 1)
337 	    {
338 	      if (MEM_P (x))
339 		reg_equiv_memory_loc[regno] = x;
340 	      else
341 		{
342 		  basic_block bb;
343 		  int new_regno;
344 
345 		  gcc_assert (REG_P (x));
346 		  new_regno = REGNO (x);
347 		  reg_renumber[regno] = new_regno;
348 		  /* Poke the regno right into regno_reg_rtx so that even
349 		     fixed regs are accepted.  */
350 		  REGNO (ivs->entries[i].pseudo) = new_regno;
351 		  /* Update global register liveness information.  */
352 		  FOR_EACH_BB (bb)
353 		    {
354 		      struct rtl_bb_info *info = bb->il.rtl;
355 
356 		      if (REGNO_REG_SET_P(info->global_live_at_start, regno))
357 			SET_REGNO_REG_SET (info->global_live_at_start,
358 					   new_regno);
359 		      if (REGNO_REG_SET_P(info->global_live_at_end, regno))
360 			SET_REGNO_REG_SET (info->global_live_at_end,
361 					   new_regno);
362 		    }
363 		}
364 	    }
365 	}
366     }
367 }
368 
369 #include "gt-integrate.h"
370