1 /* Generic hooks for the RTL middle-end.
2 Copyright (C) 2004, 2005, 2007, 2008, 2009, 2011, 2012
3 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
26 #include "rtlhooks-def.h"
31 /* For speed, we will copy the RTX hooks struct member-by-member
32 instead of doing indirect calls. For these reason, we initialize
33 *two* struct rtl_hooks globals: rtl_hooks is the one that is used
34 to actually call the hooks, while general_rtl_hooks is used
35 to restore the hooks by passes that modify them. */
37 const struct rtl_hooks general_rtl_hooks
= RTL_HOOKS_INITIALIZER
;
38 struct rtl_hooks rtl_hooks
= RTL_HOOKS_INITIALIZER
;
41 gen_lowpart_general (enum machine_mode mode
, rtx x
)
43 rtx result
= gen_lowpart_common (mode
, x
);
47 /* Handle SUBREGs and hard REGs that were rejected by
48 simplify_gen_subreg. */
49 else if (REG_P (x
) || GET_CODE (x
) == SUBREG
)
51 result
= gen_lowpart_common (mode
, copy_to_reg (x
));
52 gcc_assert (result
!= 0);
59 /* The only additional case we can do is MEM. */
60 gcc_assert (MEM_P (x
));
62 /* The following exposes the use of "x" to CSE. */
63 if (GET_MODE_SIZE (GET_MODE (x
)) <= UNITS_PER_WORD
64 && SCALAR_INT_MODE_P (GET_MODE (x
))
65 && TRULY_NOOP_TRUNCATION_MODES_P (mode
, GET_MODE (x
))
67 return gen_lowpart_general (mode
, force_reg (GET_MODE (x
), x
));
70 offset
= (MAX (GET_MODE_SIZE (GET_MODE (x
)), UNITS_PER_WORD
)
71 - MAX (GET_MODE_SIZE (mode
), UNITS_PER_WORD
));
74 /* Adjust the address so that the address-after-the-data
76 offset
-= (MIN (UNITS_PER_WORD
, GET_MODE_SIZE (mode
))
77 - MIN (UNITS_PER_WORD
, GET_MODE_SIZE (GET_MODE (x
))));
79 return adjust_address (x
, mode
, offset
);
84 reg_num_sign_bit_copies_general (const_rtx x ATTRIBUTE_UNUSED
,
85 enum machine_mode mode ATTRIBUTE_UNUSED
,
86 const_rtx known_x ATTRIBUTE_UNUSED
,
87 enum machine_mode known_mode ATTRIBUTE_UNUSED
,
88 unsigned int known_ret ATTRIBUTE_UNUSED
,
89 unsigned int *result ATTRIBUTE_UNUSED
)
95 reg_nonzero_bits_general (const_rtx x ATTRIBUTE_UNUSED
,
96 enum machine_mode mode ATTRIBUTE_UNUSED
,
97 const_rtx known_x ATTRIBUTE_UNUSED
,
98 enum machine_mode known_mode ATTRIBUTE_UNUSED
,
99 unsigned HOST_WIDE_INT known_ret ATTRIBUTE_UNUSED
,
100 unsigned HOST_WIDE_INT
*nonzero ATTRIBUTE_UNUSED
)
106 reg_truncated_to_mode_general (enum machine_mode mode ATTRIBUTE_UNUSED
,
107 const_rtx x ATTRIBUTE_UNUSED
)
112 /* Assuming that X is an rtx (e.g., MEM, REG or SUBREG) for a fixed-point
113 number, return an rtx (MEM, SUBREG, or CONST_INT) that refers to the
114 least-significant part of X.
115 MODE specifies how big a part of X to return.
117 If the requested operation cannot be done, 0 is returned.
119 This is similar to gen_lowpart_general. */
122 gen_lowpart_if_possible (enum machine_mode mode
, rtx x
)
124 rtx result
= gen_lowpart_common (mode
, x
);
130 /* This is the only other case we handle. */
134 if (WORDS_BIG_ENDIAN
)
135 offset
= (MAX (GET_MODE_SIZE (GET_MODE (x
)), UNITS_PER_WORD
)
136 - MAX (GET_MODE_SIZE (mode
), UNITS_PER_WORD
));
137 if (BYTES_BIG_ENDIAN
)
138 /* Adjust the address so that the address-after-the-data is
140 offset
-= (MIN (UNITS_PER_WORD
, GET_MODE_SIZE (mode
))
141 - MIN (UNITS_PER_WORD
, GET_MODE_SIZE (GET_MODE (x
))));
143 new_rtx
= adjust_address_nv (x
, mode
, offset
);
144 if (! memory_address_addr_space_p (mode
, XEXP (new_rtx
, 0),
150 else if (mode
!= GET_MODE (x
) && GET_MODE (x
) != VOIDmode
151 && validate_subreg (mode
, GET_MODE (x
), x
,
152 subreg_lowpart_offset (mode
, GET_MODE (x
))))
153 return gen_lowpart_SUBREG (mode
, x
);