1 /* Generic hooks for the RTL middle-end.
2 Copyright (C) 2004-2017 Free Software Foundation, Inc.
4 This file is part of GCC.
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
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
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/>. */
22 #include "coretypes.h"
27 #include "insn-config.h"
31 #include "rtlhooks-def.h"
35 /* For speed, we will copy the RTX hooks struct member-by-member
36 instead of doing indirect calls. For these reason, we initialize
37 *two* struct rtl_hooks globals: rtl_hooks is the one that is used
38 to actually call the hooks, while general_rtl_hooks is used
39 to restore the hooks by passes that modify them. */
41 const struct rtl_hooks general_rtl_hooks
= RTL_HOOKS_INITIALIZER
;
42 struct rtl_hooks rtl_hooks
= RTL_HOOKS_INITIALIZER
;
45 gen_lowpart_general (machine_mode mode
, rtx x
)
47 rtx result
= gen_lowpart_common (mode
, x
);
51 /* Handle SUBREGs and hard REGs that were rejected by
52 simplify_gen_subreg. */
53 else if (REG_P (x
) || GET_CODE (x
) == SUBREG
)
55 result
= gen_lowpart_common (mode
, copy_to_reg (x
));
56 gcc_assert (result
!= 0);
63 /* The only additional case we can do is MEM. */
64 gcc_assert (MEM_P (x
));
66 /* The following exposes the use of "x" to CSE. */
67 if (GET_MODE_SIZE (GET_MODE (x
)) <= UNITS_PER_WORD
68 && SCALAR_INT_MODE_P (GET_MODE (x
))
69 && TRULY_NOOP_TRUNCATION_MODES_P (mode
, GET_MODE (x
))
71 return gen_lowpart_general (mode
, force_reg (GET_MODE (x
), x
));
74 offset
= (MAX (GET_MODE_SIZE (GET_MODE (x
)), UNITS_PER_WORD
)
75 - MAX (GET_MODE_SIZE (mode
), UNITS_PER_WORD
));
78 /* Adjust the address so that the address-after-the-data
80 offset
-= (MIN (UNITS_PER_WORD
, GET_MODE_SIZE (mode
))
81 - MIN (UNITS_PER_WORD
, GET_MODE_SIZE (GET_MODE (x
))));
83 return adjust_address (x
, mode
, offset
);
88 reg_num_sign_bit_copies_general (const_rtx x ATTRIBUTE_UNUSED
,
89 machine_mode mode ATTRIBUTE_UNUSED
,
90 const_rtx known_x ATTRIBUTE_UNUSED
,
91 machine_mode known_mode ATTRIBUTE_UNUSED
,
92 unsigned int known_ret ATTRIBUTE_UNUSED
,
93 unsigned int *result ATTRIBUTE_UNUSED
)
99 reg_nonzero_bits_general (const_rtx x ATTRIBUTE_UNUSED
,
100 machine_mode mode ATTRIBUTE_UNUSED
,
101 const_rtx known_x ATTRIBUTE_UNUSED
,
102 machine_mode known_mode ATTRIBUTE_UNUSED
,
103 unsigned HOST_WIDE_INT known_ret ATTRIBUTE_UNUSED
,
104 unsigned HOST_WIDE_INT
*nonzero ATTRIBUTE_UNUSED
)
110 reg_truncated_to_mode_general (machine_mode mode ATTRIBUTE_UNUSED
,
111 const_rtx x ATTRIBUTE_UNUSED
)
116 /* Assuming that X is an rtx (e.g., MEM, REG or SUBREG) for a fixed-point
117 number, return an rtx (MEM, SUBREG, or CONST_INT) that refers to the
118 least-significant part of X.
119 MODE specifies how big a part of X to return.
121 If the requested operation cannot be done, 0 is returned.
123 This is similar to gen_lowpart_general. */
126 gen_lowpart_if_possible (machine_mode mode
, rtx x
)
128 rtx result
= gen_lowpart_common (mode
, x
);
134 /* This is the only other case we handle. */
138 if (WORDS_BIG_ENDIAN
)
139 offset
= (MAX (GET_MODE_SIZE (GET_MODE (x
)), UNITS_PER_WORD
)
140 - MAX (GET_MODE_SIZE (mode
), UNITS_PER_WORD
));
141 if (BYTES_BIG_ENDIAN
)
142 /* Adjust the address so that the address-after-the-data is
144 offset
-= (MIN (UNITS_PER_WORD
, GET_MODE_SIZE (mode
))
145 - MIN (UNITS_PER_WORD
, GET_MODE_SIZE (GET_MODE (x
))));
147 new_rtx
= adjust_address_nv (x
, mode
, offset
);
148 if (! memory_address_addr_space_p (mode
, XEXP (new_rtx
, 0),
154 else if (mode
!= GET_MODE (x
) && GET_MODE (x
) != VOIDmode
155 && validate_subreg (mode
, GET_MODE (x
), x
,
156 subreg_lowpart_offset (mode
, GET_MODE (x
))))
157 return gen_lowpart_SUBREG (mode
, x
);