1 /* Definitions for code generation pass of GNU compiler.
2 Copyright (C) 1987-2016 Free Software Foundation, Inc.
3
4 This file is part of GCC.
5
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
10
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
19
20 #ifndef GCC_EXPR_H
21 #define GCC_EXPR_H
22
23 /* This is the 4th arg to `expand_expr'.
24 EXPAND_STACK_PARM means we are possibly expanding a call param onto
25 the stack.
26 EXPAND_SUM means it is ok to return a PLUS rtx or MULT rtx.
27 EXPAND_INITIALIZER is similar but also record any labels on forced_labels.
28 EXPAND_CONST_ADDRESS means it is ok to return a MEM whose address
29 is a constant that is not a legitimate address.
30 EXPAND_WRITE means we are only going to write to the resulting rtx.
31 EXPAND_MEMORY means we are interested in a memory result, even if
32 the memory is constant and we could have propagated a constant value,
33 or the memory is unaligned on a STRICT_ALIGNMENT target. */
34 enum expand_modifier {EXPAND_NORMAL = 0, EXPAND_STACK_PARM, EXPAND_SUM,
35 EXPAND_CONST_ADDRESS, EXPAND_INITIALIZER, EXPAND_WRITE,
36 EXPAND_MEMORY};
37
38 /* Prevent the compiler from deferring stack pops. See
39 inhibit_defer_pop for more information. */
40 #define NO_DEFER_POP (inhibit_defer_pop += 1)
41
42 /* Allow the compiler to defer stack pops. See inhibit_defer_pop for
43 more information. */
44 #define OK_DEFER_POP (inhibit_defer_pop -= 1)
45
46 /* This structure is used to pass around information about exploded
47 unary, binary and trinary expressions between expand_expr_real_1 and
48 friends. */
49 typedef struct separate_ops
50 {
51 enum tree_code code;
52 location_t location;
53 tree type;
54 tree op0, op1, op2;
55 } *sepops;
56
57 /* This is run during target initialization to set up which modes can be
58 used directly in memory and to initialize the block move optab. */
59 extern void init_expr_target (void);
60
61 /* This is run at the start of compiling a function. */
62 extern void init_expr (void);
63
64 /* Emit some rtl insns to move data between rtx's, converting machine modes.
65 Both modes must be floating or both fixed. */
66 extern void convert_move (rtx, rtx, int);
67
68 /* Convert an rtx to specified machine mode and return the result. */
69 extern rtx convert_to_mode (machine_mode, rtx, int);
70
71 /* Convert an rtx to MODE from OLDMODE and return the result. */
72 extern rtx convert_modes (machine_mode, machine_mode, rtx, int);
73
74 /* Emit code to move a block Y to a block X. */
75
76 enum block_op_methods
77 {
78 BLOCK_OP_NORMAL,
79 BLOCK_OP_NO_LIBCALL,
80 BLOCK_OP_CALL_PARM,
81 /* Like BLOCK_OP_NORMAL, but the libcall can be tail call optimized. */
82 BLOCK_OP_TAILCALL
83 };
84
85 extern GTY(()) tree block_clear_fn;
86 extern void init_block_move_fn (const char *);
87 extern void init_block_clear_fn (const char *);
88
89 extern rtx emit_block_move (rtx, rtx, rtx, enum block_op_methods);
90 extern rtx emit_block_move_via_libcall (rtx, rtx, rtx, bool);
91 extern rtx emit_block_move_hints (rtx, rtx, rtx, enum block_op_methods,
92 unsigned int, HOST_WIDE_INT,
93 unsigned HOST_WIDE_INT,
94 unsigned HOST_WIDE_INT,
95 unsigned HOST_WIDE_INT);
96 extern bool emit_storent_insn (rtx to, rtx from);
97
98 /* Copy all or part of a value X into registers starting at REGNO.
99 The number of registers to be filled is NREGS. */
100 extern void move_block_to_reg (int, rtx, int, machine_mode);
101
102 /* Copy all or part of a BLKmode value X out of registers starting at REGNO.
103 The number of registers to be filled is NREGS. */
104 extern void move_block_from_reg (int, rtx, int);
105
106 /* Generate a non-consecutive group of registers represented by a PARALLEL. */
107 extern rtx gen_group_rtx (rtx);
108
109 /* Load a BLKmode value into non-consecutive registers represented by a
110 PARALLEL. */
111 extern void emit_group_load (rtx, rtx, tree, int);
112
113 /* Similarly, but load into new temporaries. */
114 extern rtx emit_group_load_into_temps (rtx, rtx, tree, int);
115
116 /* Move a non-consecutive group of registers represented by a PARALLEL into
117 a non-consecutive group of registers represented by a PARALLEL. */
118 extern void emit_group_move (rtx, rtx);
119
120 /* Move a group of registers represented by a PARALLEL into pseudos. */
121 extern rtx emit_group_move_into_temps (rtx);
122
123 /* Store a BLKmode value from non-consecutive registers represented by a
124 PARALLEL. */
125 extern void emit_group_store (rtx, rtx, tree, int);
126
127 extern rtx maybe_emit_group_store (rtx, tree);
128
129 /* Copy BLKmode object from a set of registers. */
130 extern void copy_blkmode_from_reg (rtx, rtx, tree);
131
132 /* Mark REG as holding a parameter for the next CALL_INSN.
133 Mode is TYPE_MODE of the non-promoted parameter, or VOIDmode. */
134 extern void use_reg_mode (rtx *, rtx, machine_mode);
135 extern void clobber_reg_mode (rtx *, rtx, machine_mode);
136
137 extern rtx copy_blkmode_to_reg (machine_mode, tree);
138
139 /* Mark REG as holding a parameter for the next CALL_INSN. */
140 static inline void
use_reg(rtx * fusage,rtx reg)141 use_reg (rtx *fusage, rtx reg)
142 {
143 use_reg_mode (fusage, reg, VOIDmode);
144 }
145
146 /* Mark REG as clobbered by the call with FUSAGE as CALL_INSN_FUNCTION_USAGE. */
147 static inline void
clobber_reg(rtx * fusage,rtx reg)148 clobber_reg (rtx *fusage, rtx reg)
149 {
150 clobber_reg_mode (fusage, reg, VOIDmode);
151 }
152
153 /* Mark NREGS consecutive regs, starting at REGNO, as holding parameters
154 for the next CALL_INSN. */
155 extern void use_regs (rtx *, int, int);
156
157 /* Mark a PARALLEL as holding a parameter for the next CALL_INSN. */
158 extern void use_group_regs (rtx *, rtx);
159
160 /* Write zeros through the storage of OBJECT.
161 If OBJECT has BLKmode, SIZE is its length in bytes. */
162 extern rtx clear_storage (rtx, rtx, enum block_op_methods);
163 extern rtx clear_storage_hints (rtx, rtx, enum block_op_methods,
164 unsigned int, HOST_WIDE_INT,
165 unsigned HOST_WIDE_INT,
166 unsigned HOST_WIDE_INT,
167 unsigned HOST_WIDE_INT);
168 /* The same, but always output an library call. */
169 rtx set_storage_via_libcall (rtx, rtx, rtx, bool);
170
171 /* Expand a setmem pattern; return true if successful. */
172 extern bool set_storage_via_setmem (rtx, rtx, rtx, unsigned int,
173 unsigned int, HOST_WIDE_INT,
174 unsigned HOST_WIDE_INT,
175 unsigned HOST_WIDE_INT,
176 unsigned HOST_WIDE_INT);
177
178 extern unsigned HOST_WIDE_INT move_by_pieces_ninsns (unsigned HOST_WIDE_INT,
179 unsigned int,
180 unsigned int);
181
182 /* Return nonzero if it is desirable to store LEN bytes generated by
183 CONSTFUN with several move instructions by store_by_pieces
184 function. CONSTFUNDATA is a pointer which will be passed as argument
185 in every CONSTFUN call.
186 ALIGN is maximum alignment we can assume.
187 MEMSETP is true if this is a real memset/bzero, not a copy
188 of a const string. */
189 extern int can_store_by_pieces (unsigned HOST_WIDE_INT,
190 rtx (*) (void *, HOST_WIDE_INT,
191 machine_mode),
192 void *, unsigned int, bool);
193
194 /* Generate several move instructions to store LEN bytes generated by
195 CONSTFUN to block TO. (A MEM rtx with BLKmode). CONSTFUNDATA is a
196 pointer which will be passed as argument in every CONSTFUN call.
197 ALIGN is maximum alignment we can assume.
198 MEMSETP is true if this is a real memset/bzero, not a copy.
199 Returns TO + LEN. */
200 extern rtx store_by_pieces (rtx, unsigned HOST_WIDE_INT,
201 rtx (*) (void *, HOST_WIDE_INT, machine_mode),
202 void *, unsigned int, bool, int);
203
204 /* Emit insns to set X from Y. */
205 extern rtx_insn *emit_move_insn (rtx, rtx);
206 extern rtx_insn *gen_move_insn (rtx, rtx);
207
208 /* Emit insns to set X from Y, with no frills. */
209 extern rtx_insn *emit_move_insn_1 (rtx, rtx);
210
211 extern rtx_insn *emit_move_complex_push (machine_mode, rtx, rtx);
212 extern rtx_insn *emit_move_complex_parts (rtx, rtx);
213 extern rtx read_complex_part (rtx, bool);
214 extern void write_complex_part (rtx, rtx, bool);
215 extern rtx read_complex_part (rtx, bool);
216 extern rtx emit_move_resolve_push (machine_mode, rtx);
217
218 /* Push a block of length SIZE (perhaps variable)
219 and return an rtx to address the beginning of the block. */
220 extern rtx push_block (rtx, int, int);
221
222 /* Generate code to push something onto the stack, given its mode and type. */
223 extern bool emit_push_insn (rtx, machine_mode, tree, rtx, unsigned int,
224 int, rtx, int, rtx, rtx, int, rtx, bool);
225
226 /* Extract the accessible bit-range from a COMPONENT_REF. */
227 extern void get_bit_range (unsigned HOST_WIDE_INT *, unsigned HOST_WIDE_INT *,
228 tree, HOST_WIDE_INT *, tree *);
229
230 /* Expand an assignment that stores the value of FROM into TO. */
231 extern void expand_assignment (tree, tree, bool);
232
233 /* Generate code for computing expression EXP,
234 and storing the value into TARGET.
235 If SUGGEST_REG is nonzero, copy the value through a register
236 and return that register, if that is possible. */
237 extern rtx store_expr_with_bounds (tree, rtx, int, bool, bool, tree);
238 extern rtx store_expr (tree, rtx, int, bool, bool);
239
240 /* Given an rtx that may include add and multiply operations,
241 generate them as insns and return a pseudo-reg containing the value.
242 Useful after calling expand_expr with 1 as sum_ok. */
243 extern rtx force_operand (rtx, rtx);
244
245 /* Work horses for expand_expr. */
246 extern rtx expand_expr_real (tree, rtx, machine_mode,
247 enum expand_modifier, rtx *, bool);
248 extern rtx expand_expr_real_1 (tree, rtx, machine_mode,
249 enum expand_modifier, rtx *, bool);
250 extern rtx expand_expr_real_2 (sepops, rtx, machine_mode,
251 enum expand_modifier);
252
253 /* Generate code for computing expression EXP.
254 An rtx for the computed value is returned. The value is never null.
255 In the case of a void EXP, const0_rtx is returned. */
256 static inline rtx
expand_expr(tree exp,rtx target,machine_mode mode,enum expand_modifier modifier)257 expand_expr (tree exp, rtx target, machine_mode mode,
258 enum expand_modifier modifier)
259 {
260 return expand_expr_real (exp, target, mode, modifier, NULL, false);
261 }
262
263 static inline rtx
expand_normal(tree exp)264 expand_normal (tree exp)
265 {
266 return expand_expr_real (exp, NULL_RTX, VOIDmode, EXPAND_NORMAL, NULL, false);
267 }
268
269
270 /* Return the tree node and offset if a given argument corresponds to
271 a string constant. */
272 extern tree string_constant (tree, tree *);
273
274 /* Two different ways of generating switch statements. */
275 extern int try_casesi (tree, tree, tree, tree, rtx, rtx, rtx, int);
276 extern int try_tablejump (tree, tree, tree, tree, rtx, rtx, int);
277
278 extern int safe_from_p (const_rtx, tree, int);
279
280 /* Get the personality libfunc for a function decl. */
281 rtx get_personality_function (tree);
282
283 /* Determine whether the LEN bytes can be moved by using several move
284 instructions. Return nonzero if a call to move_by_pieces should
285 succeed. */
286 extern int can_move_by_pieces (unsigned HOST_WIDE_INT, unsigned int);
287
288 extern unsigned HOST_WIDE_INT highest_pow2_factor (const_tree);
289
290 extern bool categorize_ctor_elements (const_tree, HOST_WIDE_INT *,
291 HOST_WIDE_INT *, bool *);
292
293 extern void expand_operands (tree, tree, rtx, rtx*, rtx*,
294 enum expand_modifier);
295
296 /* rtl.h and tree.h were included. */
297 /* Return an rtx for the size in bytes of the value of an expr. */
298 extern rtx expr_size (tree);
299
300 #endif /* GCC_EXPR_H */
301