Line data Source code
1 : /* Generic hooks for the RTL middle-end.
2 : Copyright (C) 2004-2026 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 : #include "config.h"
21 : #include "system.h"
22 : #include "coretypes.h"
23 : #include "tm.h"
24 : #include "function.h"
25 : #include "rtl.h"
26 : #include "tree.h"
27 : #include "insn-config.h"
28 : #include "memmodel.h"
29 : #include "emit-rtl.h"
30 : #include "recog.h"
31 : #include "rtlhooks-def.h"
32 : #include "explow.h"
33 : #include "target.h"
34 :
35 :
36 : /* For speed, we will copy the RTX hooks struct member-by-member
37 : instead of doing indirect calls. For these reason, we initialize
38 : *two* struct rtl_hooks globals: rtl_hooks is the one that is used
39 : to actually call the hooks, while general_rtl_hooks is used
40 : to restore the hooks by passes that modify them. */
41 :
42 : const struct rtl_hooks general_rtl_hooks = RTL_HOOKS_INITIALIZER;
43 : struct rtl_hooks rtl_hooks = RTL_HOOKS_INITIALIZER;
44 :
45 : rtx
46 4687884 : gen_lowpart_general (machine_mode mode, rtx x)
47 : {
48 4718505 : rtx result = gen_lowpart_common (mode, x);
49 :
50 4718505 : if (result)
51 : return result;
52 : /* Handle SUBREGs and hard REGs that were rejected by
53 : simplify_gen_subreg. */
54 101923 : else if (REG_P (x) || GET_CODE (x) == SUBREG)
55 : {
56 66 : result = gen_lowpart_common (mode, copy_to_reg (x));
57 66 : gcc_assert (result != 0);
58 : return result;
59 : }
60 : else
61 : {
62 : /* The only additional case we can do is MEM. */
63 101857 : gcc_assert (MEM_P (x));
64 :
65 : /* The following exposes the use of "x" to CSE. */
66 101857 : scalar_int_mode xmode;
67 101857 : if (is_a <scalar_int_mode> (GET_MODE (x), &xmode)
68 46902 : && GET_MODE_SIZE (xmode) <= UNITS_PER_WORD
69 37568 : && TRULY_NOOP_TRUNCATION_MODES_P (mode, xmode)
70 37568 : && !reload_completed)
71 30621 : return gen_lowpart_general (mode, force_reg (xmode, x));
72 :
73 71236 : poly_int64 offset = byte_lowpart_offset (mode, GET_MODE (x));
74 71236 : return adjust_address (x, mode, offset);
75 : }
76 : }
77 :
78 : rtx
79 29911180 : reg_num_sign_bit_copies_general (const_rtx, scalar_int_mode, scalar_int_mode,
80 : unsigned int *)
81 : {
82 29911180 : return NULL;
83 : }
84 :
85 : rtx
86 74876276 : reg_nonzero_bits_general (const_rtx, scalar_int_mode, scalar_int_mode,
87 : unsigned HOST_WIDE_INT *)
88 : {
89 74876276 : return NULL;
90 : }
91 :
92 : bool
93 0 : reg_truncated_to_mode_general (machine_mode mode ATTRIBUTE_UNUSED,
94 : const_rtx x ATTRIBUTE_UNUSED)
95 : {
96 0 : return false;
97 : }
98 :
99 : /* Assuming that X is an rtx (e.g., MEM, REG or SUBREG) for a fixed-point
100 : number, return an rtx (MEM, SUBREG, or CONST_INT) that refers to the
101 : least-significant part of X.
102 : MODE specifies how big a part of X to return.
103 :
104 : If the requested operation cannot be done, 0 is returned.
105 :
106 : This is similar to gen_lowpart_general. */
107 :
108 : rtx
109 24764459 : gen_lowpart_if_possible (machine_mode mode, rtx x)
110 : {
111 24764459 : rtx result = gen_lowpart_common (mode, x);
112 :
113 24764459 : if (result)
114 : return result;
115 46700 : else if (MEM_P (x))
116 : {
117 : /* This is the only other case we handle. */
118 8440 : poly_int64 offset = byte_lowpart_offset (mode, GET_MODE (x));
119 8440 : rtx new_rtx = adjust_address_nv (x, mode, offset);
120 16880 : if (! memory_address_addr_space_p (mode, XEXP (new_rtx, 0),
121 8440 : MEM_ADDR_SPACE (x)))
122 : return 0;
123 :
124 8020 : return new_rtx;
125 : }
126 38260 : else if (mode != GET_MODE (x) && GET_MODE (x) != VOIDmode && !SUBREG_P (x)
127 72681 : && validate_subreg (mode, GET_MODE (x), x,
128 : subreg_lowpart_offset (mode, GET_MODE (x))))
129 33911 : return gen_lowpart_SUBREG (mode, x);
130 : else
131 4349 : return 0;
132 : }
133 :
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