summaryrefslogtreecommitdiff
path: root/gcc/gimplify-me.c
blob: a7e9387b6480d98f36a3aac32f384968daf51080 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
/* Tree lowering to gimple for middle end use only.  
   This converts the GENERIC functions-as-trees tree representation into
   the GIMPLE form.
   Copyright (C) 2013 Free Software Foundation, Inc.
   Major work done by Sebastian Pop <s.pop@laposte.net>,
   Diego Novillo <dnovillo@redhat.com> and Jason Merrill <jason@redhat.com>.

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tree.h"
#include "stmt.h"
#include "stor-layout.h"
#include "gimple.h"
#include "gimple-iterator.h"
#include "gimplify.h"
#include "gimplify-me.h"
#include "gimple-ssa.h"
#include "stringpool.h"
#include "tree-ssanames.h"


/* Expand EXPR to list of gimple statements STMTS.  GIMPLE_TEST_F specifies
   the predicate that will hold for the result.  If VAR is not NULL, make the
   base variable of the final destination be VAR if suitable.  */

tree
force_gimple_operand_1 (tree expr, gimple_seq *stmts,
			gimple_predicate gimple_test_f, tree var)
{
  enum gimplify_status ret;
  struct gimplify_ctx gctx;
  location_t saved_location;

  *stmts = NULL;

  /* gimple_test_f might be more strict than is_gimple_val, make
     sure we pass both.  Just checking gimple_test_f doesn't work
     because most gimple predicates do not work recursively.  */
  if (is_gimple_val (expr)
      && (*gimple_test_f) (expr))
    return expr;

  push_gimplify_context (&gctx);
  gimplify_ctxp->into_ssa = gimple_in_ssa_p (cfun);
  gimplify_ctxp->allow_rhs_cond_expr = true;
  saved_location = input_location;
  input_location = UNKNOWN_LOCATION;

  if (var)
    {
      if (gimplify_ctxp->into_ssa
	  && is_gimple_reg (var))
	var = make_ssa_name (var, NULL);
      expr = build2 (MODIFY_EXPR, TREE_TYPE (var), var, expr);
    }

  if (TREE_CODE (expr) != MODIFY_EXPR
      && TREE_TYPE (expr) == void_type_node)
    {
      gimplify_and_add (expr, stmts);
      expr = NULL_TREE;
    }
  else
    {
      ret = gimplify_expr (&expr, stmts, NULL, gimple_test_f, fb_rvalue);
      gcc_assert (ret != GS_ERROR);
    }

  input_location = saved_location;
  pop_gimplify_context (NULL);

  return expr;
}

/* Expand EXPR to list of gimple statements STMTS.  If SIMPLE is true,
   force the result to be either ssa_name or an invariant, otherwise
   just force it to be a rhs expression.  If VAR is not NULL, make the
   base variable of the final destination be VAR if suitable.  */

tree
force_gimple_operand (tree expr, gimple_seq *stmts, bool simple, tree var)
{
  return force_gimple_operand_1 (expr, stmts,
				 simple ? is_gimple_val : is_gimple_reg_rhs,
				 var);
}

/* Invoke force_gimple_operand_1 for EXPR with parameters GIMPLE_TEST_F
   and VAR.  If some statements are produced, emits them at GSI.
   If BEFORE is true.  the statements are appended before GSI, otherwise
   they are appended after it.  M specifies the way GSI moves after
   insertion (GSI_SAME_STMT or GSI_CONTINUE_LINKING are the usual values).  */

tree
force_gimple_operand_gsi_1 (gimple_stmt_iterator *gsi, tree expr,
			    gimple_predicate gimple_test_f,
			    tree var, bool before,
			    enum gsi_iterator_update m)
{
  gimple_seq stmts;

  expr = force_gimple_operand_1 (expr, &stmts, gimple_test_f, var);

  if (!gimple_seq_empty_p (stmts))
    {
      if (before)
	gsi_insert_seq_before (gsi, stmts, m);
      else
	gsi_insert_seq_after (gsi, stmts, m);
    }

  return expr;
}

/* Invoke force_gimple_operand_1 for EXPR with parameter VAR.
   If SIMPLE is true, force the result to be either ssa_name or an invariant,
   otherwise just force it to be a rhs expression.  If some statements are
   produced, emits them at GSI.  If BEFORE is true, the statements are
   appended before GSI, otherwise they are appended after it.  M specifies
   the way GSI moves after insertion (GSI_SAME_STMT or GSI_CONTINUE_LINKING
   are the usual values).  */

tree
force_gimple_operand_gsi (gimple_stmt_iterator *gsi, tree expr,
			  bool simple_p, tree var, bool before,
			  enum gsi_iterator_update m)
{
  return force_gimple_operand_gsi_1 (gsi, expr,
				     simple_p
				     ? is_gimple_val : is_gimple_reg_rhs,
				     var, before, m);
}

/* Some transformations like inlining may invalidate the GIMPLE form
   for operands.  This function traverses all the operands in STMT and
   gimplifies anything that is not a valid gimple operand.  Any new
   GIMPLE statements are inserted before *GSI_P.  */

void
gimple_regimplify_operands (gimple stmt, gimple_stmt_iterator *gsi_p)
{
  size_t i, num_ops;
  tree lhs;
  gimple_seq pre = NULL;
  gimple post_stmt = NULL;
  struct gimplify_ctx gctx;

  push_gimplify_context (&gctx);
  gimplify_ctxp->into_ssa = gimple_in_ssa_p (cfun);

  switch (gimple_code (stmt))
    {
    case GIMPLE_COND:
      gimplify_expr (gimple_cond_lhs_ptr (stmt), &pre, NULL,
		     is_gimple_val, fb_rvalue);
      gimplify_expr (gimple_cond_rhs_ptr (stmt), &pre, NULL,
		     is_gimple_val, fb_rvalue);
      break;
    case GIMPLE_SWITCH:
      gimplify_expr (gimple_switch_index_ptr (stmt), &pre, NULL,
		     is_gimple_val, fb_rvalue);
      break;
    case GIMPLE_OMP_ATOMIC_LOAD:
      gimplify_expr (gimple_omp_atomic_load_rhs_ptr (stmt), &pre, NULL,
		     is_gimple_val, fb_rvalue);
      break;
    case GIMPLE_ASM:
      {
	size_t i, noutputs = gimple_asm_noutputs (stmt);
	const char *constraint, **oconstraints;
	bool allows_mem, allows_reg, is_inout;

	oconstraints
	  = (const char **) alloca ((noutputs) * sizeof (const char *));
	for (i = 0; i < noutputs; i++)
	  {
	    tree op = gimple_asm_output_op (stmt, i);
	    constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (op)));
	    oconstraints[i] = constraint;
	    parse_output_constraint (&constraint, i, 0, 0, &allows_mem,
				     &allows_reg, &is_inout);
	    gimplify_expr (&TREE_VALUE (op), &pre, NULL,
			   is_inout ? is_gimple_min_lval : is_gimple_lvalue,
			   fb_lvalue | fb_mayfail);
	  }
	for (i = 0; i < gimple_asm_ninputs (stmt); i++)
	  {
	    tree op = gimple_asm_input_op (stmt, i);
	    constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (op)));
	    parse_input_constraint (&constraint, 0, 0, noutputs, 0,
				    oconstraints, &allows_mem, &allows_reg);
	    if (TREE_ADDRESSABLE (TREE_TYPE (TREE_VALUE (op))) && allows_mem)
	      allows_reg = 0;
	    if (!allows_reg && allows_mem)
	      gimplify_expr (&TREE_VALUE (op), &pre, NULL,
			     is_gimple_lvalue, fb_lvalue | fb_mayfail);
	    else
	      gimplify_expr (&TREE_VALUE (op), &pre, NULL,
			     is_gimple_asm_val, fb_rvalue);
	  }
      }
      break;
    default:
      /* NOTE: We start gimplifying operands from last to first to
	 make sure that side-effects on the RHS of calls, assignments
	 and ASMs are executed before the LHS.  The ordering is not
	 important for other statements.  */
      num_ops = gimple_num_ops (stmt);
      for (i = num_ops; i > 0; i--)
	{
	  tree op = gimple_op (stmt, i - 1);
	  if (op == NULL_TREE)
	    continue;
	  if (i == 1 && (is_gimple_call (stmt) || is_gimple_assign (stmt)))
	    gimplify_expr (&op, &pre, NULL, is_gimple_lvalue, fb_lvalue);
	  else if (i == 2
		   && is_gimple_assign (stmt)
		   && num_ops == 2
		   && get_gimple_rhs_class (gimple_expr_code (stmt))
		      == GIMPLE_SINGLE_RHS)
	    gimplify_expr (&op, &pre, NULL,
			   rhs_predicate_for (gimple_assign_lhs (stmt)),
			   fb_rvalue);
	  else if (i == 2 && is_gimple_call (stmt))
	    {
	      if (TREE_CODE (op) == FUNCTION_DECL)
		continue;
	      gimplify_expr (&op, &pre, NULL, is_gimple_call_addr, fb_rvalue);
	    }
	  else
	    gimplify_expr (&op, &pre, NULL, is_gimple_val, fb_rvalue);
	  gimple_set_op (stmt, i - 1, op);
	}

      lhs = gimple_get_lhs (stmt);
      /* If the LHS changed it in a way that requires a simple RHS,
	 create temporary.  */
      if (lhs && !is_gimple_reg (lhs))
	{
	  bool need_temp = false;

	  if (is_gimple_assign (stmt)
	      && num_ops == 2
	      && get_gimple_rhs_class (gimple_expr_code (stmt))
		 == GIMPLE_SINGLE_RHS)
	    gimplify_expr (gimple_assign_rhs1_ptr (stmt), &pre, NULL,
			   rhs_predicate_for (gimple_assign_lhs (stmt)),
			   fb_rvalue);
	  else if (is_gimple_reg (lhs))
	    {
	      if (is_gimple_reg_type (TREE_TYPE (lhs)))
		{
		  if (is_gimple_call (stmt))
		    {
		      i = gimple_call_flags (stmt);
		      if ((i & ECF_LOOPING_CONST_OR_PURE)
			  || !(i & (ECF_CONST | ECF_PURE)))
			need_temp = true;
		    }
		  if (stmt_can_throw_internal (stmt))
		    need_temp = true;
		}
	    }
	  else
	    {
	      if (is_gimple_reg_type (TREE_TYPE (lhs)))
		need_temp = true;
	      else if (TYPE_MODE (TREE_TYPE (lhs)) != BLKmode)
		{
		  if (is_gimple_call (stmt))
		    {
		      tree fndecl = gimple_call_fndecl (stmt);

		      if (!aggregate_value_p (TREE_TYPE (lhs), fndecl)
			  && !(fndecl && DECL_RESULT (fndecl)
			       && DECL_BY_REFERENCE (DECL_RESULT (fndecl))))
			need_temp = true;
		    }
		  else
		    need_temp = true;
		}
	    }
	  if (need_temp)
	    {
	      tree temp = create_tmp_reg (TREE_TYPE (lhs), NULL);
	      if (gimple_in_ssa_p (cfun))
		temp = make_ssa_name (temp, NULL);
	      gimple_set_lhs (stmt, temp);
	      post_stmt = gimple_build_assign (lhs, temp);
	    }
	}
      break;
    }

  if (!gimple_seq_empty_p (pre))
    gsi_insert_seq_before (gsi_p, pre, GSI_SAME_STMT);
  if (post_stmt)
    gsi_insert_after (gsi_p, post_stmt, GSI_NEW_STMT);

  pop_gimplify_context (NULL);
}