| /* Generic hooks for the RTL middle-end. |
| Copyright (C) 2004-2017 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 "function.h" |
| #include "rtl.h" |
| #include "tree.h" |
| #include "insn-config.h" |
| #include "memmodel.h" |
| #include "emit-rtl.h" |
| #include "recog.h" |
| #include "rtlhooks-def.h" |
| #include "explow.h" |
| #include "target.h" |
| |
| |
| /* 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 (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 |
| { |
| /* The only additional case we can do is MEM. */ |
| gcc_assert (MEM_P (x)); |
| |
| /* The following exposes the use of "x" to CSE. */ |
| scalar_int_mode xmode; |
| if (is_a <scalar_int_mode> (GET_MODE (x), &xmode) |
| && GET_MODE_SIZE (xmode) <= UNITS_PER_WORD |
| && TRULY_NOOP_TRUNCATION_MODES_P (mode, xmode) |
| && !reload_completed) |
| return gen_lowpart_general (mode, force_reg (xmode, x)); |
| |
| HOST_WIDE_INT offset = byte_lowpart_offset (mode, GET_MODE (x)); |
| return adjust_address (x, mode, offset); |
| } |
| } |
| |
| rtx |
| reg_num_sign_bit_copies_general (const_rtx, scalar_int_mode, scalar_int_mode, |
| unsigned int *) |
| { |
| return NULL; |
| } |
| |
| rtx |
| reg_nonzero_bits_general (const_rtx, scalar_int_mode, scalar_int_mode, |
| unsigned HOST_WIDE_INT *) |
| { |
| return NULL; |
| } |
| |
| bool |
| reg_truncated_to_mode_general (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 (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. */ |
| HOST_WIDE_INT offset = byte_lowpart_offset (mode, GET_MODE (x)); |
| rtx new_rtx = adjust_address_nv (x, mode, offset); |
| if (! memory_address_addr_space_p (mode, XEXP (new_rtx, 0), |
| MEM_ADDR_SPACE (x))) |
| 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; |
| } |
| |