--- /dev/null
+/* Generic hooks for the RTL middle-end.
+ Copyright (C) 2004, 2005, 2007, 2008 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "rtl.h"
+#include "rtlhooks-def.h"
+#include "expr.h"
+#include "recog.h"
+\f
+
+/* For speed, we will copy the RTX hooks struct member-by-member
+ instead of doing indirect calls. For these reason, we initialize
+ *two* struct rtl_hooks globals: rtl_hooks is the one that is used
+ to actually call the hooks, while general_rtl_hooks is used
+ to restore the hooks by passes that modify them. */
+
+const struct rtl_hooks general_rtl_hooks = RTL_HOOKS_INITIALIZER;
+struct rtl_hooks rtl_hooks = RTL_HOOKS_INITIALIZER;
+
+rtx
+gen_lowpart_general (enum machine_mode mode, rtx x)
+{
+ rtx result = gen_lowpart_common (mode, x);
+
+ if (result)
+ return result;
+ /* Handle SUBREGs and hard REGs that were rejected by
+ simplify_gen_subreg. */
+ else if (REG_P (x) || GET_CODE (x) == SUBREG)
+ {
+ result = gen_lowpart_common (mode, copy_to_reg (x));
+ gcc_assert (result != 0);
+ return result;
+ }
+ else
+ {
+ int offset = 0;
+
+ /* The only additional case we can do is MEM. */
+ gcc_assert (MEM_P (x));
+
+ /* The following exposes the use of "x" to CSE. */
+ if (GET_MODE_SIZE (GET_MODE (x)) <= UNITS_PER_WORD
+ && SCALAR_INT_MODE_P (GET_MODE (x))
+ && TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (mode),
+ GET_MODE_BITSIZE (GET_MODE (x)))
+ && !reload_completed)
+ return gen_lowpart_general (mode, force_reg (GET_MODE (x), x));
+
+ if (WORDS_BIG_ENDIAN)
+ offset = (MAX (GET_MODE_SIZE (GET_MODE (x)), UNITS_PER_WORD)
+ - MAX (GET_MODE_SIZE (mode), UNITS_PER_WORD));
+
+ if (BYTES_BIG_ENDIAN)
+ /* Adjust the address so that the address-after-the-data
+ is unchanged. */
+ offset -= (MIN (UNITS_PER_WORD, GET_MODE_SIZE (mode))
+ - MIN (UNITS_PER_WORD, GET_MODE_SIZE (GET_MODE (x))));
+
+ return adjust_address (x, mode, offset);
+ }
+}
+
+/* Similar to gen_lowpart, but cannot emit any instruction via
+ copy_to_reg or force_reg. Mainly used in simplify-rtx.c. */
+rtx
+gen_lowpart_no_emit_general (enum machine_mode mode, rtx x)
+{
+ rtx result = gen_lowpart_if_possible (mode, x);
+ if (result)
+ return result;
+ else
+ return x;
+}
+
+rtx
+reg_num_sign_bit_copies_general (const_rtx x ATTRIBUTE_UNUSED,
+ enum machine_mode mode ATTRIBUTE_UNUSED,
+ const_rtx known_x ATTRIBUTE_UNUSED,
+ enum machine_mode known_mode ATTRIBUTE_UNUSED,
+ unsigned int known_ret ATTRIBUTE_UNUSED,
+ unsigned int *result ATTRIBUTE_UNUSED)
+{
+ return NULL;
+}
+
+rtx
+reg_nonzero_bits_general (const_rtx x ATTRIBUTE_UNUSED,
+ enum machine_mode mode ATTRIBUTE_UNUSED,
+ const_rtx known_x ATTRIBUTE_UNUSED,
+ enum machine_mode known_mode ATTRIBUTE_UNUSED,
+ unsigned HOST_WIDE_INT known_ret ATTRIBUTE_UNUSED,
+ unsigned HOST_WIDE_INT *nonzero ATTRIBUTE_UNUSED)
+{
+ return NULL;
+}
+
+bool
+reg_truncated_to_mode_general (enum machine_mode mode ATTRIBUTE_UNUSED,
+ const_rtx x ATTRIBUTE_UNUSED)
+{
+ return false;
+}
+
+/* Assuming that X is an rtx (e.g., MEM, REG or SUBREG) for a fixed-point
+ number, return an rtx (MEM, SUBREG, or CONST_INT) that refers to the
+ least-significant part of X.
+ MODE specifies how big a part of X to return.
+
+ If the requested operation cannot be done, 0 is returned.
+
+ This is similar to gen_lowpart_general. */
+
+rtx
+gen_lowpart_if_possible (enum machine_mode mode, rtx x)
+{
+ rtx result = gen_lowpart_common (mode, x);
+
+ if (result)
+ return result;
+ else if (MEM_P (x))
+ {
+ /* This is the only other case we handle. */
+ int offset = 0;
+ rtx new_rtx;
+
+ if (WORDS_BIG_ENDIAN)
+ offset = (MAX (GET_MODE_SIZE (GET_MODE (x)), UNITS_PER_WORD)
+ - MAX (GET_MODE_SIZE (mode), UNITS_PER_WORD));
+ if (BYTES_BIG_ENDIAN)
+ /* Adjust the address so that the address-after-the-data is
+ unchanged. */
+ offset -= (MIN (UNITS_PER_WORD, GET_MODE_SIZE (mode))
+ - MIN (UNITS_PER_WORD, GET_MODE_SIZE (GET_MODE (x))));
+
+ new_rtx = adjust_address_nv (x, mode, offset);
+ if (! memory_address_p (mode, XEXP (new_rtx, 0)))
+ return 0;
+
+ return new_rtx;
+ }
+ else if (mode != GET_MODE (x) && GET_MODE (x) != VOIDmode
+ && validate_subreg (mode, GET_MODE (x), x,
+ subreg_lowpart_offset (mode, GET_MODE (x))))
+ return gen_lowpart_SUBREG (mode, x);
+ else
+ return 0;
+}
+\f
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