134 lines
3.7 KiB
C
134 lines
3.7 KiB
C
/* Generic hooks for the RTL middle-end.
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Copyright (C) 2004-2019 Free Software Foundation, Inc.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 3, or (at your option) any later
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version.
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING3. If not see
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<http://www.gnu.org/licenses/>. */
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#include "config.h"
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#include "system.h"
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#include "coretypes.h"
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#include "tm.h"
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#include "function.h"
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#include "rtl.h"
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#include "tree.h"
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#include "insn-config.h"
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#include "memmodel.h"
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#include "emit-rtl.h"
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#include "recog.h"
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#include "rtlhooks-def.h"
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#include "explow.h"
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#include "target.h"
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/* For speed, we will copy the RTX hooks struct member-by-member
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instead of doing indirect calls. For these reason, we initialize
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*two* struct rtl_hooks globals: rtl_hooks is the one that is used
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to actually call the hooks, while general_rtl_hooks is used
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to restore the hooks by passes that modify them. */
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const struct rtl_hooks general_rtl_hooks = RTL_HOOKS_INITIALIZER;
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struct rtl_hooks rtl_hooks = RTL_HOOKS_INITIALIZER;
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rtx
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gen_lowpart_general (machine_mode mode, rtx x)
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{
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rtx result = gen_lowpart_common (mode, x);
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if (result)
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return result;
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/* Handle SUBREGs and hard REGs that were rejected by
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simplify_gen_subreg. */
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else if (REG_P (x) || GET_CODE (x) == SUBREG)
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{
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result = gen_lowpart_common (mode, copy_to_reg (x));
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gcc_assert (result != 0);
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return result;
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}
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else
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{
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/* The only additional case we can do is MEM. */
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gcc_assert (MEM_P (x));
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/* The following exposes the use of "x" to CSE. */
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scalar_int_mode xmode;
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if (is_a <scalar_int_mode> (GET_MODE (x), &xmode)
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&& GET_MODE_SIZE (xmode) <= UNITS_PER_WORD
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&& TRULY_NOOP_TRUNCATION_MODES_P (mode, xmode)
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&& !reload_completed)
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return gen_lowpart_general (mode, force_reg (xmode, x));
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poly_int64 offset = byte_lowpart_offset (mode, GET_MODE (x));
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return adjust_address (x, mode, offset);
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}
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}
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rtx
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reg_num_sign_bit_copies_general (const_rtx, scalar_int_mode, scalar_int_mode,
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unsigned int *)
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{
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return NULL;
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}
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rtx
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reg_nonzero_bits_general (const_rtx, scalar_int_mode, scalar_int_mode,
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unsigned HOST_WIDE_INT *)
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{
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return NULL;
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}
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bool
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reg_truncated_to_mode_general (machine_mode mode ATTRIBUTE_UNUSED,
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const_rtx x ATTRIBUTE_UNUSED)
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{
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return false;
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}
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/* Assuming that X is an rtx (e.g., MEM, REG or SUBREG) for a fixed-point
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number, return an rtx (MEM, SUBREG, or CONST_INT) that refers to the
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least-significant part of X.
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MODE specifies how big a part of X to return.
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If the requested operation cannot be done, 0 is returned.
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This is similar to gen_lowpart_general. */
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rtx
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gen_lowpart_if_possible (machine_mode mode, rtx x)
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{
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rtx result = gen_lowpart_common (mode, x);
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if (result)
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return result;
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else if (MEM_P (x))
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{
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/* This is the only other case we handle. */
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poly_int64 offset = byte_lowpart_offset (mode, GET_MODE (x));
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rtx new_rtx = adjust_address_nv (x, mode, offset);
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if (! memory_address_addr_space_p (mode, XEXP (new_rtx, 0),
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MEM_ADDR_SPACE (x)))
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return 0;
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return new_rtx;
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}
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else if (mode != GET_MODE (x) && GET_MODE (x) != VOIDmode && !SUBREG_P (x)
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&& validate_subreg (mode, GET_MODE (x), x,
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subreg_lowpart_offset (mode, GET_MODE (x))))
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return gen_lowpart_SUBREG (mode, x);
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else
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return 0;
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}
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