1 /* Generic hooks for the RTL middle-end.
2 Copyright (C) 2004-2015 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"
25 #include "rtlhooks-def.h"
30 #include "hard-reg-set.h"
34 #include "statistics.h"
38 #include "insn-config.h"
50 /* For speed, we will copy the RTX hooks struct member-by-member
51 instead of doing indirect calls. For these reason, we initialize
52 *two* struct rtl_hooks globals: rtl_hooks is the one that is used
53 to actually call the hooks, while general_rtl_hooks is used
54 to restore the hooks by passes that modify them. */
56 const struct rtl_hooks general_rtl_hooks
= RTL_HOOKS_INITIALIZER
;
57 struct rtl_hooks rtl_hooks
= RTL_HOOKS_INITIALIZER
;
60 gen_lowpart_general (machine_mode mode
, rtx x
)
62 rtx result
= gen_lowpart_common (mode
, x
);
66 /* Handle SUBREGs and hard REGs that were rejected by
67 simplify_gen_subreg. */
68 else if (REG_P (x
) || GET_CODE (x
) == SUBREG
)
70 result
= gen_lowpart_common (mode
, copy_to_reg (x
));
71 gcc_assert (result
!= 0);
78 /* The only additional case we can do is MEM. */
79 gcc_assert (MEM_P (x
));
81 /* The following exposes the use of "x" to CSE. */
82 if (GET_MODE_SIZE (GET_MODE (x
)) <= UNITS_PER_WORD
83 && SCALAR_INT_MODE_P (GET_MODE (x
))
84 && TRULY_NOOP_TRUNCATION_MODES_P (mode
, GET_MODE (x
))
86 return gen_lowpart_general (mode
, force_reg (GET_MODE (x
), x
));
89 offset
= (MAX (GET_MODE_SIZE (GET_MODE (x
)), UNITS_PER_WORD
)
90 - MAX (GET_MODE_SIZE (mode
), UNITS_PER_WORD
));
93 /* Adjust the address so that the address-after-the-data
95 offset
-= (MIN (UNITS_PER_WORD
, GET_MODE_SIZE (mode
))
96 - MIN (UNITS_PER_WORD
, GET_MODE_SIZE (GET_MODE (x
))));
98 return adjust_address (x
, mode
, offset
);
103 reg_num_sign_bit_copies_general (const_rtx x ATTRIBUTE_UNUSED
,
104 machine_mode mode ATTRIBUTE_UNUSED
,
105 const_rtx known_x ATTRIBUTE_UNUSED
,
106 machine_mode known_mode ATTRIBUTE_UNUSED
,
107 unsigned int known_ret ATTRIBUTE_UNUSED
,
108 unsigned int *result ATTRIBUTE_UNUSED
)
114 reg_nonzero_bits_general (const_rtx x ATTRIBUTE_UNUSED
,
115 machine_mode mode ATTRIBUTE_UNUSED
,
116 const_rtx known_x ATTRIBUTE_UNUSED
,
117 machine_mode known_mode ATTRIBUTE_UNUSED
,
118 unsigned HOST_WIDE_INT known_ret ATTRIBUTE_UNUSED
,
119 unsigned HOST_WIDE_INT
*nonzero ATTRIBUTE_UNUSED
)
125 reg_truncated_to_mode_general (machine_mode mode ATTRIBUTE_UNUSED
,
126 const_rtx x ATTRIBUTE_UNUSED
)
131 /* Assuming that X is an rtx (e.g., MEM, REG or SUBREG) for a fixed-point
132 number, return an rtx (MEM, SUBREG, or CONST_INT) that refers to the
133 least-significant part of X.
134 MODE specifies how big a part of X to return.
136 If the requested operation cannot be done, 0 is returned.
138 This is similar to gen_lowpart_general. */
141 gen_lowpart_if_possible (machine_mode mode
, rtx x
)
143 rtx result
= gen_lowpart_common (mode
, x
);
149 /* This is the only other case we handle. */
153 if (WORDS_BIG_ENDIAN
)
154 offset
= (MAX (GET_MODE_SIZE (GET_MODE (x
)), UNITS_PER_WORD
)
155 - MAX (GET_MODE_SIZE (mode
), UNITS_PER_WORD
));
156 if (BYTES_BIG_ENDIAN
)
157 /* Adjust the address so that the address-after-the-data is
159 offset
-= (MIN (UNITS_PER_WORD
, GET_MODE_SIZE (mode
))
160 - MIN (UNITS_PER_WORD
, GET_MODE_SIZE (GET_MODE (x
))));
162 new_rtx
= adjust_address_nv (x
, mode
, offset
);
163 if (! memory_address_addr_space_p (mode
, XEXP (new_rtx
, 0),
169 else if (mode
!= GET_MODE (x
) && GET_MODE (x
) != VOIDmode
170 && validate_subreg (mode
, GET_MODE (x
), x
,
171 subreg_lowpart_offset (mode
, GET_MODE (x
))))
172 return gen_lowpart_SUBREG (mode
, x
);