[8833] | 1 | /* Subroutines for manipulating rtx's in semantically interesting ways. |
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| 2 | Copyright (C) 1987, 1991, 1994, 1995 Free Software Foundation, Inc. |
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| 3 | |
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| 4 | This file is part of GNU CC. |
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| 5 | |
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| 6 | GNU CC is free software; you can redistribute it and/or modify |
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| 7 | it under the terms of the GNU General Public License as published by |
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| 8 | the Free Software Foundation; either version 2, or (at your option) |
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| 9 | any later version. |
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| 10 | |
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| 11 | GNU CC is distributed in the hope that it will be useful, |
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| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 14 | GNU General Public License for more details. |
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| 15 | |
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| 16 | You should have received a copy of the GNU General Public License |
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| 17 | along with GNU CC; see the file COPYING. If not, write to |
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| 18 | the Free Software Foundation, 59 Temple Place - Suite 330, |
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| 19 | Boston, MA 02111-1307, USA. */ |
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| 20 | |
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| 21 | |
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| 22 | #include "config.h" |
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| 23 | #include "rtl.h" |
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| 24 | #include "tree.h" |
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| 25 | #include "flags.h" |
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| 26 | #include "expr.h" |
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| 27 | #include "hard-reg-set.h" |
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| 28 | #include "insn-config.h" |
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| 29 | #include "recog.h" |
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| 30 | #include "insn-flags.h" |
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| 31 | #include "insn-codes.h" |
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| 32 | |
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| 33 | static rtx break_out_memory_refs PROTO((rtx)); |
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| 34 | |
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| 35 | /* Return an rtx for the sum of X and the integer C. |
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| 36 | |
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| 37 | This function should be used via the `plus_constant' macro. */ |
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| 38 | |
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| 39 | rtx |
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| 40 | plus_constant_wide (x, c) |
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| 41 | register rtx x; |
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| 42 | register HOST_WIDE_INT c; |
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| 43 | { |
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| 44 | register RTX_CODE code; |
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| 45 | register enum machine_mode mode; |
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| 46 | register rtx tem; |
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| 47 | int all_constant = 0; |
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| 48 | |
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| 49 | if (c == 0) |
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| 50 | return x; |
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| 51 | |
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| 52 | restart: |
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| 53 | |
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| 54 | code = GET_CODE (x); |
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| 55 | mode = GET_MODE (x); |
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| 56 | switch (code) |
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| 57 | { |
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| 58 | case CONST_INT: |
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| 59 | return GEN_INT (INTVAL (x) + c); |
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| 60 | |
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| 61 | case CONST_DOUBLE: |
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| 62 | { |
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| 63 | HOST_WIDE_INT l1 = CONST_DOUBLE_LOW (x); |
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| 64 | HOST_WIDE_INT h1 = CONST_DOUBLE_HIGH (x); |
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| 65 | HOST_WIDE_INT l2 = c; |
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| 66 | HOST_WIDE_INT h2 = c < 0 ? ~0 : 0; |
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| 67 | HOST_WIDE_INT lv, hv; |
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| 68 | |
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| 69 | add_double (l1, h1, l2, h2, &lv, &hv); |
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| 70 | |
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| 71 | return immed_double_const (lv, hv, VOIDmode); |
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| 72 | } |
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| 73 | |
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| 74 | case MEM: |
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| 75 | /* If this is a reference to the constant pool, try replacing it with |
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| 76 | a reference to a new constant. If the resulting address isn't |
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| 77 | valid, don't return it because we have no way to validize it. */ |
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| 78 | if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF |
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| 79 | && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0))) |
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| 80 | { |
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| 81 | tem |
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| 82 | = force_const_mem (GET_MODE (x), |
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| 83 | plus_constant (get_pool_constant (XEXP (x, 0)), |
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| 84 | c)); |
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| 85 | if (memory_address_p (GET_MODE (tem), XEXP (tem, 0))) |
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| 86 | return tem; |
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| 87 | } |
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| 88 | break; |
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| 89 | |
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| 90 | case CONST: |
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| 91 | /* If adding to something entirely constant, set a flag |
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| 92 | so that we can add a CONST around the result. */ |
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| 93 | x = XEXP (x, 0); |
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| 94 | all_constant = 1; |
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| 95 | goto restart; |
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| 96 | |
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| 97 | case SYMBOL_REF: |
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| 98 | case LABEL_REF: |
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| 99 | all_constant = 1; |
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| 100 | break; |
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| 101 | |
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| 102 | case PLUS: |
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| 103 | /* The interesting case is adding the integer to a sum. |
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| 104 | Look for constant term in the sum and combine |
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| 105 | with C. For an integer constant term, we make a combined |
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| 106 | integer. For a constant term that is not an explicit integer, |
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| 107 | we cannot really combine, but group them together anyway. |
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| 108 | |
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| 109 | Use a recursive call in case the remaining operand is something |
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| 110 | that we handle specially, such as a SYMBOL_REF. */ |
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| 111 | |
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| 112 | if (GET_CODE (XEXP (x, 1)) == CONST_INT) |
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| 113 | return plus_constant (XEXP (x, 0), c + INTVAL (XEXP (x, 1))); |
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| 114 | else if (CONSTANT_P (XEXP (x, 0))) |
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| 115 | return gen_rtx (PLUS, mode, |
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| 116 | plus_constant (XEXP (x, 0), c), |
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| 117 | XEXP (x, 1)); |
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| 118 | else if (CONSTANT_P (XEXP (x, 1))) |
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| 119 | return gen_rtx (PLUS, mode, |
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| 120 | XEXP (x, 0), |
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| 121 | plus_constant (XEXP (x, 1), c)); |
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| 122 | } |
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| 123 | |
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| 124 | if (c != 0) |
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| 125 | x = gen_rtx (PLUS, mode, x, GEN_INT (c)); |
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| 126 | |
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| 127 | if (GET_CODE (x) == SYMBOL_REF || GET_CODE (x) == LABEL_REF) |
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| 128 | return x; |
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| 129 | else if (all_constant) |
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| 130 | return gen_rtx (CONST, mode, x); |
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| 131 | else |
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| 132 | return x; |
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| 133 | } |
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| 134 | |
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| 135 | /* This is the same as `plus_constant', except that it handles LO_SUM. |
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| 136 | |
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| 137 | This function should be used via the `plus_constant_for_output' macro. */ |
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| 138 | |
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| 139 | rtx |
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| 140 | plus_constant_for_output_wide (x, c) |
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| 141 | register rtx x; |
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| 142 | register HOST_WIDE_INT c; |
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| 143 | { |
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| 144 | register RTX_CODE code = GET_CODE (x); |
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| 145 | register enum machine_mode mode = GET_MODE (x); |
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| 146 | int all_constant = 0; |
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| 147 | |
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| 148 | if (GET_CODE (x) == LO_SUM) |
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| 149 | return gen_rtx (LO_SUM, mode, XEXP (x, 0), |
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| 150 | plus_constant_for_output (XEXP (x, 1), c)); |
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| 151 | |
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| 152 | else |
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| 153 | return plus_constant (x, c); |
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| 154 | } |
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| 155 | |
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| 156 | /* If X is a sum, return a new sum like X but lacking any constant terms. |
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| 157 | Add all the removed constant terms into *CONSTPTR. |
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| 158 | X itself is not altered. The result != X if and only if |
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| 159 | it is not isomorphic to X. */ |
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| 160 | |
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| 161 | rtx |
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| 162 | eliminate_constant_term (x, constptr) |
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| 163 | rtx x; |
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| 164 | rtx *constptr; |
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| 165 | { |
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| 166 | register rtx x0, x1; |
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| 167 | rtx tem; |
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| 168 | |
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| 169 | if (GET_CODE (x) != PLUS) |
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| 170 | return x; |
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| 171 | |
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| 172 | /* First handle constants appearing at this level explicitly. */ |
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| 173 | if (GET_CODE (XEXP (x, 1)) == CONST_INT |
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| 174 | && 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x), *constptr, |
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| 175 | XEXP (x, 1))) |
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| 176 | && GET_CODE (tem) == CONST_INT) |
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| 177 | { |
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| 178 | *constptr = tem; |
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| 179 | return eliminate_constant_term (XEXP (x, 0), constptr); |
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| 180 | } |
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| 181 | |
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| 182 | tem = const0_rtx; |
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| 183 | x0 = eliminate_constant_term (XEXP (x, 0), &tem); |
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| 184 | x1 = eliminate_constant_term (XEXP (x, 1), &tem); |
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| 185 | if ((x1 != XEXP (x, 1) || x0 != XEXP (x, 0)) |
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| 186 | && 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x), |
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| 187 | *constptr, tem)) |
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| 188 | && GET_CODE (tem) == CONST_INT) |
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| 189 | { |
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| 190 | *constptr = tem; |
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| 191 | return gen_rtx (PLUS, GET_MODE (x), x0, x1); |
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| 192 | } |
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| 193 | |
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| 194 | return x; |
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| 195 | } |
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| 196 | |
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| 197 | /* Returns the insn that next references REG after INSN, or 0 |
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| 198 | if REG is clobbered before next referenced or we cannot find |
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| 199 | an insn that references REG in a straight-line piece of code. */ |
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| 200 | |
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| 201 | rtx |
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| 202 | find_next_ref (reg, insn) |
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| 203 | rtx reg; |
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| 204 | rtx insn; |
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| 205 | { |
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| 206 | rtx next; |
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| 207 | |
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| 208 | for (insn = NEXT_INSN (insn); insn; insn = next) |
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| 209 | { |
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| 210 | next = NEXT_INSN (insn); |
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| 211 | if (GET_CODE (insn) == NOTE) |
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| 212 | continue; |
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| 213 | if (GET_CODE (insn) == CODE_LABEL |
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| 214 | || GET_CODE (insn) == BARRIER) |
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| 215 | return 0; |
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| 216 | if (GET_CODE (insn) == INSN |
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| 217 | || GET_CODE (insn) == JUMP_INSN |
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| 218 | || GET_CODE (insn) == CALL_INSN) |
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| 219 | { |
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| 220 | if (reg_set_p (reg, insn)) |
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| 221 | return 0; |
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| 222 | if (reg_mentioned_p (reg, PATTERN (insn))) |
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| 223 | return insn; |
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| 224 | if (GET_CODE (insn) == JUMP_INSN) |
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| 225 | { |
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| 226 | if (simplejump_p (insn)) |
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| 227 | next = JUMP_LABEL (insn); |
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| 228 | else |
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| 229 | return 0; |
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| 230 | } |
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| 231 | if (GET_CODE (insn) == CALL_INSN |
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| 232 | && REGNO (reg) < FIRST_PSEUDO_REGISTER |
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| 233 | && call_used_regs[REGNO (reg)]) |
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| 234 | return 0; |
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| 235 | } |
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| 236 | else |
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| 237 | abort (); |
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| 238 | } |
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| 239 | return 0; |
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| 240 | } |
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| 241 | |
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| 242 | /* Return an rtx for the size in bytes of the value of EXP. */ |
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| 243 | |
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| 244 | rtx |
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| 245 | expr_size (exp) |
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| 246 | tree exp; |
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| 247 | { |
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| 248 | tree size = size_in_bytes (TREE_TYPE (exp)); |
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| 249 | |
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| 250 | if (TREE_CODE (size) != INTEGER_CST |
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| 251 | && contains_placeholder_p (size)) |
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| 252 | size = build (WITH_RECORD_EXPR, sizetype, size, exp); |
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| 253 | |
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| 254 | return expand_expr (size, NULL_RTX, TYPE_MODE (sizetype), 0); |
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| 255 | } |
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| 256 | |
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| 257 | /* Return a copy of X in which all memory references |
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| 258 | and all constants that involve symbol refs |
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| 259 | have been replaced with new temporary registers. |
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| 260 | Also emit code to load the memory locations and constants |
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| 261 | into those registers. |
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| 262 | |
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| 263 | If X contains no such constants or memory references, |
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| 264 | X itself (not a copy) is returned. |
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| 265 | |
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| 266 | If a constant is found in the address that is not a legitimate constant |
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| 267 | in an insn, it is left alone in the hope that it might be valid in the |
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| 268 | address. |
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| 269 | |
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| 270 | X may contain no arithmetic except addition, subtraction and multiplication. |
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| 271 | Values returned by expand_expr with 1 for sum_ok fit this constraint. */ |
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| 272 | |
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| 273 | static rtx |
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| 274 | break_out_memory_refs (x) |
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| 275 | register rtx x; |
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| 276 | { |
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| 277 | if (GET_CODE (x) == MEM |
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| 278 | || (CONSTANT_P (x) && CONSTANT_ADDRESS_P (x) |
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| 279 | && GET_MODE (x) != VOIDmode)) |
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| 280 | x = force_reg (GET_MODE (x), x); |
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| 281 | else if (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS |
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| 282 | || GET_CODE (x) == MULT) |
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| 283 | { |
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| 284 | register rtx op0 = break_out_memory_refs (XEXP (x, 0)); |
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| 285 | register rtx op1 = break_out_memory_refs (XEXP (x, 1)); |
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| 286 | |
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| 287 | if (op0 != XEXP (x, 0) || op1 != XEXP (x, 1)) |
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| 288 | x = gen_rtx (GET_CODE (x), Pmode, op0, op1); |
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| 289 | } |
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| 290 | |
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| 291 | return x; |
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| 292 | } |
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| 293 | |
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| 294 | #ifdef POINTERS_EXTEND_UNSIGNED |
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| 295 | |
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| 296 | /* Given X, a memory address in ptr_mode, convert it to an address |
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| 297 | in Pmode, or vice versa (TO_MODE says which way). We take advantage of |
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| 298 | the fact that pointers are not allowed to overflow by commuting arithmetic |
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| 299 | operations over conversions so that address arithmetic insns can be |
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| 300 | used. */ |
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| 301 | |
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| 302 | rtx |
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| 303 | convert_memory_address (to_mode, x) |
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| 304 | enum machine_mode to_mode; |
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| 305 | rtx x; |
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| 306 | { |
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| 307 | rtx temp; |
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| 308 | |
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| 309 | switch (GET_CODE (x)) |
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| 310 | { |
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| 311 | case CONST_INT: |
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| 312 | case CONST_DOUBLE: |
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| 313 | return x; |
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| 314 | |
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| 315 | case LABEL_REF: |
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| 316 | return gen_rtx (LABEL_REF, to_mode, XEXP (x, 0)); |
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| 317 | |
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| 318 | case SYMBOL_REF: |
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| 319 | temp = gen_rtx (SYMBOL_REF, to_mode, XSTR (x, 0)); |
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| 320 | SYMBOL_REF_FLAG (temp) = SYMBOL_REF_FLAG (x); |
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| 321 | return temp; |
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| 322 | |
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| 323 | case PLUS: |
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| 324 | case MULT: |
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| 325 | return gen_rtx (GET_CODE (x), to_mode, |
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| 326 | convert_memory_address (to_mode, XEXP (x, 0)), |
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| 327 | convert_memory_address (to_mode, XEXP (x, 1))); |
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| 328 | |
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| 329 | case CONST: |
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| 330 | return gen_rtx (CONST, to_mode, |
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| 331 | convert_memory_address (to_mode, XEXP (x, 0))); |
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| 332 | |
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| 333 | default: |
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| 334 | return convert_modes (to_mode, |
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| 335 | to_mode == ptr_mode ? Pmode : ptr_mode, |
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| 336 | x, POINTERS_EXTEND_UNSIGNED); |
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| 337 | } |
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| 338 | } |
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| 339 | #endif |
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| 340 | |
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| 341 | /* Given a memory address or facsimile X, construct a new address, |
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| 342 | currently equivalent, that is stable: future stores won't change it. |
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| 343 | |
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| 344 | X must be composed of constants, register and memory references |
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| 345 | combined with addition, subtraction and multiplication: |
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| 346 | in other words, just what you can get from expand_expr if sum_ok is 1. |
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| 347 | |
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| 348 | Works by making copies of all regs and memory locations used |
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| 349 | by X and combining them the same way X does. |
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| 350 | You could also stabilize the reference to this address |
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| 351 | by copying the address to a register with copy_to_reg; |
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| 352 | but then you wouldn't get indexed addressing in the reference. */ |
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| 353 | |
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| 354 | rtx |
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| 355 | copy_all_regs (x) |
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| 356 | register rtx x; |
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| 357 | { |
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| 358 | if (GET_CODE (x) == REG) |
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| 359 | { |
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| 360 | if (REGNO (x) != FRAME_POINTER_REGNUM |
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| 361 | #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM |
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| 362 | && REGNO (x) != HARD_FRAME_POINTER_REGNUM |
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| 363 | #endif |
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| 364 | ) |
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| 365 | x = copy_to_reg (x); |
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| 366 | } |
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| 367 | else if (GET_CODE (x) == MEM) |
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| 368 | x = copy_to_reg (x); |
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| 369 | else if (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS |
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| 370 | || GET_CODE (x) == MULT) |
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| 371 | { |
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| 372 | register rtx op0 = copy_all_regs (XEXP (x, 0)); |
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| 373 | register rtx op1 = copy_all_regs (XEXP (x, 1)); |
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| 374 | if (op0 != XEXP (x, 0) || op1 != XEXP (x, 1)) |
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| 375 | x = gen_rtx (GET_CODE (x), Pmode, op0, op1); |
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| 376 | } |
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| 377 | return x; |
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| 378 | } |
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| 379 | |
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| 380 | /* Return something equivalent to X but valid as a memory address |
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| 381 | for something of mode MODE. When X is not itself valid, this |
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| 382 | works by copying X or subexpressions of it into registers. */ |
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| 383 | |
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| 384 | rtx |
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| 385 | memory_address (mode, x) |
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| 386 | enum machine_mode mode; |
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| 387 | register rtx x; |
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| 388 | { |
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| 389 | register rtx oldx = x; |
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| 390 | |
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| 391 | #ifdef POINTERS_EXTEND_UNSIGNED |
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| 392 | if (GET_MODE (x) == ptr_mode) |
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| 393 | x = convert_memory_address (Pmode, x); |
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| 394 | #endif |
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| 395 | |
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| 396 | /* By passing constant addresses thru registers |
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| 397 | we get a chance to cse them. */ |
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| 398 | if (! cse_not_expected && CONSTANT_P (x) && CONSTANT_ADDRESS_P (x)) |
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| 399 | x = force_reg (Pmode, x); |
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| 400 | |
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| 401 | /* Accept a QUEUED that refers to a REG |
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| 402 | even though that isn't a valid address. |
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| 403 | On attempting to put this in an insn we will call protect_from_queue |
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| 404 | which will turn it into a REG, which is valid. */ |
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| 405 | else if (GET_CODE (x) == QUEUED |
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| 406 | && GET_CODE (QUEUED_VAR (x)) == REG) |
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| 407 | ; |
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| 408 | |
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| 409 | /* We get better cse by rejecting indirect addressing at this stage. |
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| 410 | Let the combiner create indirect addresses where appropriate. |
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| 411 | For now, generate the code so that the subexpressions useful to share |
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| 412 | are visible. But not if cse won't be done! */ |
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| 413 | else |
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| 414 | { |
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| 415 | if (! cse_not_expected && GET_CODE (x) != REG) |
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| 416 | x = break_out_memory_refs (x); |
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| 417 | |
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| 418 | /* At this point, any valid address is accepted. */ |
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| 419 | GO_IF_LEGITIMATE_ADDRESS (mode, x, win); |
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| 420 | |
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| 421 | /* If it was valid before but breaking out memory refs invalidated it, |
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| 422 | use it the old way. */ |
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| 423 | if (memory_address_p (mode, oldx)) |
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| 424 | goto win2; |
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| 425 | |
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| 426 | /* Perform machine-dependent transformations on X |
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| 427 | in certain cases. This is not necessary since the code |
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| 428 | below can handle all possible cases, but machine-dependent |
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| 429 | transformations can make better code. */ |
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| 430 | LEGITIMIZE_ADDRESS (x, oldx, mode, win); |
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| 431 | |
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| 432 | /* PLUS and MULT can appear in special ways |
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| 433 | as the result of attempts to make an address usable for indexing. |
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| 434 | Usually they are dealt with by calling force_operand, below. |
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| 435 | But a sum containing constant terms is special |
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| 436 | if removing them makes the sum a valid address: |
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| 437 | then we generate that address in a register |
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| 438 | and index off of it. We do this because it often makes |
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| 439 | shorter code, and because the addresses thus generated |
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| 440 | in registers often become common subexpressions. */ |
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| 441 | if (GET_CODE (x) == PLUS) |
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| 442 | { |
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| 443 | rtx constant_term = const0_rtx; |
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| 444 | rtx y = eliminate_constant_term (x, &constant_term); |
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| 445 | if (constant_term == const0_rtx |
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| 446 | || ! memory_address_p (mode, y)) |
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| 447 | x = force_operand (x, NULL_RTX); |
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| 448 | else |
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| 449 | { |
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| 450 | y = gen_rtx (PLUS, GET_MODE (x), copy_to_reg (y), constant_term); |
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| 451 | if (! memory_address_p (mode, y)) |
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| 452 | x = force_operand (x, NULL_RTX); |
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| 453 | else |
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| 454 | x = y; |
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| 455 | } |
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| 456 | } |
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| 457 | |
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| 458 | else if (GET_CODE (x) == MULT || GET_CODE (x) == MINUS) |
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| 459 | x = force_operand (x, NULL_RTX); |
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| 460 | |
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| 461 | /* If we have a register that's an invalid address, |
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| 462 | it must be a hard reg of the wrong class. Copy it to a pseudo. */ |
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| 463 | else if (GET_CODE (x) == REG) |
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| 464 | x = copy_to_reg (x); |
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| 465 | |
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| 466 | /* Last resort: copy the value to a register, since |
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| 467 | the register is a valid address. */ |
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| 468 | else |
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| 469 | x = force_reg (Pmode, x); |
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| 470 | |
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| 471 | goto done; |
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| 472 | |
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| 473 | win2: |
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| 474 | x = oldx; |
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| 475 | win: |
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| 476 | if (flag_force_addr && ! cse_not_expected && GET_CODE (x) != REG |
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| 477 | /* Don't copy an addr via a reg if it is one of our stack slots. */ |
---|
| 478 | && ! (GET_CODE (x) == PLUS |
---|
| 479 | && (XEXP (x, 0) == virtual_stack_vars_rtx |
---|
| 480 | || XEXP (x, 0) == virtual_incoming_args_rtx))) |
---|
| 481 | { |
---|
| 482 | if (general_operand (x, Pmode)) |
---|
| 483 | x = force_reg (Pmode, x); |
---|
| 484 | else |
---|
| 485 | x = force_operand (x, NULL_RTX); |
---|
| 486 | } |
---|
| 487 | } |
---|
| 488 | |
---|
| 489 | done: |
---|
| 490 | |
---|
| 491 | /* If we didn't change the address, we are done. Otherwise, mark |
---|
| 492 | a reg as a pointer if we have REG or REG + CONST_INT. */ |
---|
| 493 | if (oldx == x) |
---|
| 494 | return x; |
---|
| 495 | else if (GET_CODE (x) == REG) |
---|
| 496 | mark_reg_pointer (x); |
---|
| 497 | else if (GET_CODE (x) == PLUS |
---|
| 498 | && GET_CODE (XEXP (x, 0)) == REG |
---|
| 499 | && GET_CODE (XEXP (x, 1)) == CONST_INT) |
---|
| 500 | mark_reg_pointer (XEXP (x, 0)); |
---|
| 501 | |
---|
| 502 | /* OLDX may have been the address on a temporary. Update the address |
---|
| 503 | to indicate that X is now used. */ |
---|
| 504 | update_temp_slot_address (oldx, x); |
---|
| 505 | |
---|
| 506 | return x; |
---|
| 507 | } |
---|
| 508 | |
---|
| 509 | /* Like `memory_address' but pretend `flag_force_addr' is 0. */ |
---|
| 510 | |
---|
| 511 | rtx |
---|
| 512 | memory_address_noforce (mode, x) |
---|
| 513 | enum machine_mode mode; |
---|
| 514 | rtx x; |
---|
| 515 | { |
---|
| 516 | int ambient_force_addr = flag_force_addr; |
---|
| 517 | rtx val; |
---|
| 518 | |
---|
| 519 | flag_force_addr = 0; |
---|
| 520 | val = memory_address (mode, x); |
---|
| 521 | flag_force_addr = ambient_force_addr; |
---|
| 522 | return val; |
---|
| 523 | } |
---|
| 524 | |
---|
| 525 | /* Convert a mem ref into one with a valid memory address. |
---|
| 526 | Pass through anything else unchanged. */ |
---|
| 527 | |
---|
| 528 | rtx |
---|
| 529 | validize_mem (ref) |
---|
| 530 | rtx ref; |
---|
| 531 | { |
---|
| 532 | if (GET_CODE (ref) != MEM) |
---|
| 533 | return ref; |
---|
| 534 | if (memory_address_p (GET_MODE (ref), XEXP (ref, 0))) |
---|
| 535 | return ref; |
---|
| 536 | /* Don't alter REF itself, since that is probably a stack slot. */ |
---|
| 537 | return change_address (ref, GET_MODE (ref), XEXP (ref, 0)); |
---|
| 538 | } |
---|
| 539 | |
---|
| 540 | /* Return a modified copy of X with its memory address copied |
---|
| 541 | into a temporary register to protect it from side effects. |
---|
| 542 | If X is not a MEM, it is returned unchanged (and not copied). |
---|
| 543 | Perhaps even if it is a MEM, if there is no need to change it. */ |
---|
| 544 | |
---|
| 545 | rtx |
---|
| 546 | stabilize (x) |
---|
| 547 | rtx x; |
---|
| 548 | { |
---|
| 549 | register rtx addr; |
---|
| 550 | if (GET_CODE (x) != MEM) |
---|
| 551 | return x; |
---|
| 552 | addr = XEXP (x, 0); |
---|
| 553 | if (rtx_unstable_p (addr)) |
---|
| 554 | { |
---|
| 555 | rtx temp = copy_all_regs (addr); |
---|
| 556 | rtx mem; |
---|
| 557 | if (GET_CODE (temp) != REG) |
---|
| 558 | temp = copy_to_reg (temp); |
---|
| 559 | mem = gen_rtx (MEM, GET_MODE (x), temp); |
---|
| 560 | |
---|
| 561 | /* Mark returned memref with in_struct if it's in an array or |
---|
| 562 | structure. Copy const and volatile from original memref. */ |
---|
| 563 | |
---|
| 564 | MEM_IN_STRUCT_P (mem) = MEM_IN_STRUCT_P (x) || GET_CODE (addr) == PLUS; |
---|
| 565 | RTX_UNCHANGING_P (mem) = RTX_UNCHANGING_P (x); |
---|
| 566 | MEM_VOLATILE_P (mem) = MEM_VOLATILE_P (x); |
---|
| 567 | return mem; |
---|
| 568 | } |
---|
| 569 | return x; |
---|
| 570 | } |
---|
| 571 | |
---|
| 572 | /* Copy the value or contents of X to a new temp reg and return that reg. */ |
---|
| 573 | |
---|
| 574 | rtx |
---|
| 575 | copy_to_reg (x) |
---|
| 576 | rtx x; |
---|
| 577 | { |
---|
| 578 | register rtx temp = gen_reg_rtx (GET_MODE (x)); |
---|
| 579 | |
---|
| 580 | /* If not an operand, must be an address with PLUS and MULT so |
---|
| 581 | do the computation. */ |
---|
| 582 | if (! general_operand (x, VOIDmode)) |
---|
| 583 | x = force_operand (x, temp); |
---|
| 584 | |
---|
| 585 | if (x != temp) |
---|
| 586 | emit_move_insn (temp, x); |
---|
| 587 | |
---|
| 588 | return temp; |
---|
| 589 | } |
---|
| 590 | |
---|
| 591 | /* Like copy_to_reg but always give the new register mode Pmode |
---|
| 592 | in case X is a constant. */ |
---|
| 593 | |
---|
| 594 | rtx |
---|
| 595 | copy_addr_to_reg (x) |
---|
| 596 | rtx x; |
---|
| 597 | { |
---|
| 598 | return copy_to_mode_reg (Pmode, x); |
---|
| 599 | } |
---|
| 600 | |
---|
| 601 | /* Like copy_to_reg but always give the new register mode MODE |
---|
| 602 | in case X is a constant. */ |
---|
| 603 | |
---|
| 604 | rtx |
---|
| 605 | copy_to_mode_reg (mode, x) |
---|
| 606 | enum machine_mode mode; |
---|
| 607 | rtx x; |
---|
| 608 | { |
---|
| 609 | register rtx temp = gen_reg_rtx (mode); |
---|
| 610 | |
---|
| 611 | /* If not an operand, must be an address with PLUS and MULT so |
---|
| 612 | do the computation. */ |
---|
| 613 | if (! general_operand (x, VOIDmode)) |
---|
| 614 | x = force_operand (x, temp); |
---|
| 615 | |
---|
| 616 | if (GET_MODE (x) != mode && GET_MODE (x) != VOIDmode) |
---|
| 617 | abort (); |
---|
| 618 | if (x != temp) |
---|
| 619 | emit_move_insn (temp, x); |
---|
| 620 | return temp; |
---|
| 621 | } |
---|
| 622 | |
---|
| 623 | /* Load X into a register if it is not already one. |
---|
| 624 | Use mode MODE for the register. |
---|
| 625 | X should be valid for mode MODE, but it may be a constant which |
---|
| 626 | is valid for all integer modes; that's why caller must specify MODE. |
---|
| 627 | |
---|
| 628 | The caller must not alter the value in the register we return, |
---|
| 629 | since we mark it as a "constant" register. */ |
---|
| 630 | |
---|
| 631 | rtx |
---|
| 632 | force_reg (mode, x) |
---|
| 633 | enum machine_mode mode; |
---|
| 634 | rtx x; |
---|
| 635 | { |
---|
| 636 | register rtx temp, insn, set; |
---|
| 637 | |
---|
| 638 | if (GET_CODE (x) == REG) |
---|
| 639 | return x; |
---|
| 640 | temp = gen_reg_rtx (mode); |
---|
| 641 | insn = emit_move_insn (temp, x); |
---|
| 642 | |
---|
| 643 | /* Let optimizers know that TEMP's value never changes |
---|
| 644 | and that X can be substituted for it. Don't get confused |
---|
| 645 | if INSN set something else (such as a SUBREG of TEMP). */ |
---|
| 646 | if (CONSTANT_P (x) |
---|
| 647 | && (set = single_set (insn)) != 0 |
---|
| 648 | && SET_DEST (set) == temp) |
---|
| 649 | { |
---|
| 650 | rtx note = find_reg_note (insn, REG_EQUAL, NULL_RTX); |
---|
| 651 | |
---|
| 652 | if (note) |
---|
| 653 | XEXP (note, 0) = x; |
---|
| 654 | else |
---|
| 655 | REG_NOTES (insn) = gen_rtx (EXPR_LIST, REG_EQUAL, x, REG_NOTES (insn)); |
---|
| 656 | } |
---|
| 657 | return temp; |
---|
| 658 | } |
---|
| 659 | |
---|
| 660 | /* If X is a memory ref, copy its contents to a new temp reg and return |
---|
| 661 | that reg. Otherwise, return X. */ |
---|
| 662 | |
---|
| 663 | rtx |
---|
| 664 | force_not_mem (x) |
---|
| 665 | rtx x; |
---|
| 666 | { |
---|
| 667 | register rtx temp; |
---|
| 668 | if (GET_CODE (x) != MEM || GET_MODE (x) == BLKmode) |
---|
| 669 | return x; |
---|
| 670 | temp = gen_reg_rtx (GET_MODE (x)); |
---|
| 671 | emit_move_insn (temp, x); |
---|
| 672 | return temp; |
---|
| 673 | } |
---|
| 674 | |
---|
| 675 | /* Copy X to TARGET (if it's nonzero and a reg) |
---|
| 676 | or to a new temp reg and return that reg. |
---|
| 677 | MODE is the mode to use for X in case it is a constant. */ |
---|
| 678 | |
---|
| 679 | rtx |
---|
| 680 | copy_to_suggested_reg (x, target, mode) |
---|
| 681 | rtx x, target; |
---|
| 682 | enum machine_mode mode; |
---|
| 683 | { |
---|
| 684 | register rtx temp; |
---|
| 685 | |
---|
| 686 | if (target && GET_CODE (target) == REG) |
---|
| 687 | temp = target; |
---|
| 688 | else |
---|
| 689 | temp = gen_reg_rtx (mode); |
---|
| 690 | |
---|
| 691 | emit_move_insn (temp, x); |
---|
| 692 | return temp; |
---|
| 693 | } |
---|
| 694 | |
---|
| 695 | /* Return the mode to use to store a scalar of TYPE and MODE. |
---|
| 696 | PUNSIGNEDP points to the signedness of the type and may be adjusted |
---|
| 697 | to show what signedness to use on extension operations. |
---|
| 698 | |
---|
| 699 | FOR_CALL is non-zero if this call is promoting args for a call. */ |
---|
| 700 | |
---|
| 701 | enum machine_mode |
---|
| 702 | promote_mode (type, mode, punsignedp, for_call) |
---|
| 703 | tree type; |
---|
| 704 | enum machine_mode mode; |
---|
| 705 | int *punsignedp; |
---|
| 706 | int for_call; |
---|
| 707 | { |
---|
| 708 | enum tree_code code = TREE_CODE (type); |
---|
| 709 | int unsignedp = *punsignedp; |
---|
| 710 | |
---|
| 711 | #ifdef PROMOTE_FOR_CALL_ONLY |
---|
| 712 | if (! for_call) |
---|
| 713 | return mode; |
---|
| 714 | #endif |
---|
| 715 | |
---|
| 716 | switch (code) |
---|
| 717 | { |
---|
| 718 | #ifdef PROMOTE_MODE |
---|
| 719 | case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE: |
---|
| 720 | case CHAR_TYPE: case REAL_TYPE: case OFFSET_TYPE: |
---|
| 721 | PROMOTE_MODE (mode, unsignedp, type); |
---|
| 722 | break; |
---|
| 723 | #endif |
---|
| 724 | |
---|
| 725 | #ifdef POINTERS_EXTEND_UNSIGNED |
---|
| 726 | case POINTER_TYPE: |
---|
| 727 | mode = Pmode; |
---|
| 728 | unsignedp = POINTERS_EXTEND_UNSIGNED; |
---|
| 729 | break; |
---|
| 730 | #endif |
---|
| 731 | } |
---|
| 732 | |
---|
| 733 | *punsignedp = unsignedp; |
---|
| 734 | return mode; |
---|
| 735 | } |
---|
| 736 | |
---|
| 737 | /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes). |
---|
| 738 | This pops when ADJUST is positive. ADJUST need not be constant. */ |
---|
| 739 | |
---|
| 740 | void |
---|
| 741 | adjust_stack (adjust) |
---|
| 742 | rtx adjust; |
---|
| 743 | { |
---|
| 744 | rtx temp; |
---|
| 745 | adjust = protect_from_queue (adjust, 0); |
---|
| 746 | |
---|
| 747 | if (adjust == const0_rtx) |
---|
| 748 | return; |
---|
| 749 | |
---|
| 750 | temp = expand_binop (Pmode, |
---|
| 751 | #ifdef STACK_GROWS_DOWNWARD |
---|
| 752 | add_optab, |
---|
| 753 | #else |
---|
| 754 | sub_optab, |
---|
| 755 | #endif |
---|
| 756 | stack_pointer_rtx, adjust, stack_pointer_rtx, 0, |
---|
| 757 | OPTAB_LIB_WIDEN); |
---|
| 758 | |
---|
| 759 | if (temp != stack_pointer_rtx) |
---|
| 760 | emit_move_insn (stack_pointer_rtx, temp); |
---|
| 761 | } |
---|
| 762 | |
---|
| 763 | /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes). |
---|
| 764 | This pushes when ADJUST is positive. ADJUST need not be constant. */ |
---|
| 765 | |
---|
| 766 | void |
---|
| 767 | anti_adjust_stack (adjust) |
---|
| 768 | rtx adjust; |
---|
| 769 | { |
---|
| 770 | rtx temp; |
---|
| 771 | adjust = protect_from_queue (adjust, 0); |
---|
| 772 | |
---|
| 773 | if (adjust == const0_rtx) |
---|
| 774 | return; |
---|
| 775 | |
---|
| 776 | temp = expand_binop (Pmode, |
---|
| 777 | #ifdef STACK_GROWS_DOWNWARD |
---|
| 778 | sub_optab, |
---|
| 779 | #else |
---|
| 780 | add_optab, |
---|
| 781 | #endif |
---|
| 782 | stack_pointer_rtx, adjust, stack_pointer_rtx, 0, |
---|
| 783 | OPTAB_LIB_WIDEN); |
---|
| 784 | |
---|
| 785 | if (temp != stack_pointer_rtx) |
---|
| 786 | emit_move_insn (stack_pointer_rtx, temp); |
---|
| 787 | } |
---|
| 788 | |
---|
| 789 | /* Round the size of a block to be pushed up to the boundary required |
---|
| 790 | by this machine. SIZE is the desired size, which need not be constant. */ |
---|
| 791 | |
---|
| 792 | rtx |
---|
| 793 | round_push (size) |
---|
| 794 | rtx size; |
---|
| 795 | { |
---|
| 796 | #ifdef STACK_BOUNDARY |
---|
| 797 | int align = STACK_BOUNDARY / BITS_PER_UNIT; |
---|
| 798 | if (align == 1) |
---|
| 799 | return size; |
---|
| 800 | if (GET_CODE (size) == CONST_INT) |
---|
| 801 | { |
---|
| 802 | int new = (INTVAL (size) + align - 1) / align * align; |
---|
| 803 | if (INTVAL (size) != new) |
---|
| 804 | size = GEN_INT (new); |
---|
| 805 | } |
---|
| 806 | else |
---|
| 807 | { |
---|
| 808 | /* CEIL_DIV_EXPR needs to worry about the addition overflowing, |
---|
| 809 | but we know it can't. So add ourselves and then do TRUNC_DIV_EXPR. */ |
---|
| 810 | size = expand_binop (Pmode, add_optab, size, GEN_INT (align - 1), |
---|
| 811 | NULL_RTX, 1, OPTAB_LIB_WIDEN); |
---|
| 812 | size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size, GEN_INT (align), |
---|
| 813 | NULL_RTX, 1); |
---|
| 814 | size = expand_mult (Pmode, size, GEN_INT (align), NULL_RTX, 1); |
---|
| 815 | } |
---|
| 816 | #endif /* STACK_BOUNDARY */ |
---|
| 817 | return size; |
---|
| 818 | } |
---|
| 819 | |
---|
| 820 | /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer |
---|
| 821 | to a previously-created save area. If no save area has been allocated, |
---|
| 822 | this function will allocate one. If a save area is specified, it |
---|
| 823 | must be of the proper mode. |
---|
| 824 | |
---|
| 825 | The insns are emitted after insn AFTER, if nonzero, otherwise the insns |
---|
| 826 | are emitted at the current position. */ |
---|
| 827 | |
---|
| 828 | void |
---|
| 829 | emit_stack_save (save_level, psave, after) |
---|
| 830 | enum save_level save_level; |
---|
| 831 | rtx *psave; |
---|
| 832 | rtx after; |
---|
| 833 | { |
---|
| 834 | rtx sa = *psave; |
---|
| 835 | /* The default is that we use a move insn and save in a Pmode object. */ |
---|
| 836 | rtx (*fcn) () = gen_move_insn; |
---|
| 837 | enum machine_mode mode = Pmode; |
---|
| 838 | |
---|
| 839 | /* See if this machine has anything special to do for this kind of save. */ |
---|
| 840 | switch (save_level) |
---|
| 841 | { |
---|
| 842 | #ifdef HAVE_save_stack_block |
---|
| 843 | case SAVE_BLOCK: |
---|
| 844 | if (HAVE_save_stack_block) |
---|
| 845 | { |
---|
| 846 | fcn = gen_save_stack_block; |
---|
| 847 | mode = insn_operand_mode[CODE_FOR_save_stack_block][0]; |
---|
| 848 | } |
---|
| 849 | break; |
---|
| 850 | #endif |
---|
| 851 | #ifdef HAVE_save_stack_function |
---|
| 852 | case SAVE_FUNCTION: |
---|
| 853 | if (HAVE_save_stack_function) |
---|
| 854 | { |
---|
| 855 | fcn = gen_save_stack_function; |
---|
| 856 | mode = insn_operand_mode[CODE_FOR_save_stack_function][0]; |
---|
| 857 | } |
---|
| 858 | break; |
---|
| 859 | #endif |
---|
| 860 | #ifdef HAVE_save_stack_nonlocal |
---|
| 861 | case SAVE_NONLOCAL: |
---|
| 862 | if (HAVE_save_stack_nonlocal) |
---|
| 863 | { |
---|
| 864 | fcn = gen_save_stack_nonlocal; |
---|
| 865 | mode = insn_operand_mode[(int) CODE_FOR_save_stack_nonlocal][0]; |
---|
| 866 | } |
---|
| 867 | break; |
---|
| 868 | #endif |
---|
| 869 | } |
---|
| 870 | |
---|
| 871 | /* If there is no save area and we have to allocate one, do so. Otherwise |
---|
| 872 | verify the save area is the proper mode. */ |
---|
| 873 | |
---|
| 874 | if (sa == 0) |
---|
| 875 | { |
---|
| 876 | if (mode != VOIDmode) |
---|
| 877 | { |
---|
| 878 | if (save_level == SAVE_NONLOCAL) |
---|
| 879 | *psave = sa = assign_stack_local (mode, GET_MODE_SIZE (mode), 0); |
---|
| 880 | else |
---|
| 881 | *psave = sa = gen_reg_rtx (mode); |
---|
| 882 | } |
---|
| 883 | } |
---|
| 884 | else |
---|
| 885 | { |
---|
| 886 | if (mode == VOIDmode || GET_MODE (sa) != mode) |
---|
| 887 | abort (); |
---|
| 888 | } |
---|
| 889 | |
---|
| 890 | if (after) |
---|
| 891 | { |
---|
| 892 | rtx seq; |
---|
| 893 | |
---|
| 894 | start_sequence (); |
---|
| 895 | /* We must validize inside the sequence, to ensure that any instructions |
---|
| 896 | created by the validize call also get moved to the right place. */ |
---|
| 897 | if (sa != 0) |
---|
| 898 | sa = validize_mem (sa); |
---|
| 899 | emit_insn (fcn (sa, stack_pointer_rtx)); |
---|
| 900 | seq = gen_sequence (); |
---|
| 901 | end_sequence (); |
---|
| 902 | emit_insn_after (seq, after); |
---|
| 903 | } |
---|
| 904 | else |
---|
| 905 | { |
---|
| 906 | if (sa != 0) |
---|
| 907 | sa = validize_mem (sa); |
---|
| 908 | emit_insn (fcn (sa, stack_pointer_rtx)); |
---|
| 909 | } |
---|
| 910 | } |
---|
| 911 | |
---|
| 912 | /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save |
---|
| 913 | area made by emit_stack_save. If it is zero, we have nothing to do. |
---|
| 914 | |
---|
| 915 | Put any emitted insns after insn AFTER, if nonzero, otherwise at |
---|
| 916 | current position. */ |
---|
| 917 | |
---|
| 918 | void |
---|
| 919 | emit_stack_restore (save_level, sa, after) |
---|
| 920 | enum save_level save_level; |
---|
| 921 | rtx after; |
---|
| 922 | rtx sa; |
---|
| 923 | { |
---|
| 924 | /* The default is that we use a move insn. */ |
---|
| 925 | rtx (*fcn) () = gen_move_insn; |
---|
| 926 | |
---|
| 927 | /* See if this machine has anything special to do for this kind of save. */ |
---|
| 928 | switch (save_level) |
---|
| 929 | { |
---|
| 930 | #ifdef HAVE_restore_stack_block |
---|
| 931 | case SAVE_BLOCK: |
---|
| 932 | if (HAVE_restore_stack_block) |
---|
| 933 | fcn = gen_restore_stack_block; |
---|
| 934 | break; |
---|
| 935 | #endif |
---|
| 936 | #ifdef HAVE_restore_stack_function |
---|
| 937 | case SAVE_FUNCTION: |
---|
| 938 | if (HAVE_restore_stack_function) |
---|
| 939 | fcn = gen_restore_stack_function; |
---|
| 940 | break; |
---|
| 941 | #endif |
---|
| 942 | #ifdef HAVE_restore_stack_nonlocal |
---|
| 943 | |
---|
| 944 | case SAVE_NONLOCAL: |
---|
| 945 | if (HAVE_restore_stack_nonlocal) |
---|
| 946 | fcn = gen_restore_stack_nonlocal; |
---|
| 947 | break; |
---|
| 948 | #endif |
---|
| 949 | } |
---|
| 950 | |
---|
| 951 | if (sa != 0) |
---|
| 952 | sa = validize_mem (sa); |
---|
| 953 | |
---|
| 954 | if (after) |
---|
| 955 | { |
---|
| 956 | rtx seq; |
---|
| 957 | |
---|
| 958 | start_sequence (); |
---|
| 959 | emit_insn (fcn (stack_pointer_rtx, sa)); |
---|
| 960 | seq = gen_sequence (); |
---|
| 961 | end_sequence (); |
---|
| 962 | emit_insn_after (seq, after); |
---|
| 963 | } |
---|
| 964 | else |
---|
| 965 | emit_insn (fcn (stack_pointer_rtx, sa)); |
---|
| 966 | } |
---|
| 967 | |
---|
| 968 | /* Return an rtx representing the address of an area of memory dynamically |
---|
| 969 | pushed on the stack. This region of memory is always aligned to |
---|
| 970 | a multiple of BIGGEST_ALIGNMENT. |
---|
| 971 | |
---|
| 972 | Any required stack pointer alignment is preserved. |
---|
| 973 | |
---|
| 974 | SIZE is an rtx representing the size of the area. |
---|
| 975 | TARGET is a place in which the address can be placed. |
---|
| 976 | |
---|
| 977 | KNOWN_ALIGN is the alignment (in bits) that we know SIZE has. */ |
---|
| 978 | |
---|
| 979 | rtx |
---|
| 980 | allocate_dynamic_stack_space (size, target, known_align) |
---|
| 981 | rtx size; |
---|
| 982 | rtx target; |
---|
| 983 | int known_align; |
---|
| 984 | { |
---|
| 985 | /* If we're asking for zero bytes, it doesn't matter what we point |
---|
| 986 | to since we can't dereference it. But return a reasonable |
---|
| 987 | address anyway. */ |
---|
| 988 | if (size == const0_rtx) |
---|
| 989 | return virtual_stack_dynamic_rtx; |
---|
| 990 | |
---|
| 991 | /* Otherwise, show we're calling alloca or equivalent. */ |
---|
| 992 | current_function_calls_alloca = 1; |
---|
| 993 | |
---|
| 994 | /* Ensure the size is in the proper mode. */ |
---|
| 995 | if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode) |
---|
| 996 | size = convert_to_mode (Pmode, size, 1); |
---|
| 997 | |
---|
| 998 | /* We will need to ensure that the address we return is aligned to |
---|
| 999 | BIGGEST_ALIGNMENT. If STACK_DYNAMIC_OFFSET is defined, we don't |
---|
| 1000 | always know its final value at this point in the compilation (it |
---|
| 1001 | might depend on the size of the outgoing parameter lists, for |
---|
| 1002 | example), so we must align the value to be returned in that case. |
---|
| 1003 | (Note that STACK_DYNAMIC_OFFSET will have a default non-zero value if |
---|
| 1004 | STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined). |
---|
| 1005 | We must also do an alignment operation on the returned value if |
---|
| 1006 | the stack pointer alignment is less strict that BIGGEST_ALIGNMENT. |
---|
| 1007 | |
---|
| 1008 | If we have to align, we must leave space in SIZE for the hole |
---|
| 1009 | that might result from the alignment operation. */ |
---|
| 1010 | |
---|
| 1011 | #if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET) || defined (ALLOCATE_OUTGOING_ARGS) || ! defined (STACK_BOUNDARY) |
---|
| 1012 | #define MUST_ALIGN 1 |
---|
| 1013 | #else |
---|
| 1014 | #define MUST_ALIGN (STACK_BOUNDARY < BIGGEST_ALIGNMENT) |
---|
| 1015 | #endif |
---|
| 1016 | |
---|
| 1017 | if (MUST_ALIGN) |
---|
| 1018 | { |
---|
| 1019 | if (GET_CODE (size) == CONST_INT) |
---|
| 1020 | size = GEN_INT (INTVAL (size) |
---|
| 1021 | + (BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1)); |
---|
| 1022 | else |
---|
| 1023 | size = expand_binop (Pmode, add_optab, size, |
---|
| 1024 | GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1), |
---|
| 1025 | NULL_RTX, 1, OPTAB_LIB_WIDEN); |
---|
| 1026 | } |
---|
| 1027 | |
---|
| 1028 | #ifdef SETJMP_VIA_SAVE_AREA |
---|
| 1029 | /* If setjmp restores regs from a save area in the stack frame, |
---|
| 1030 | avoid clobbering the reg save area. Note that the offset of |
---|
| 1031 | virtual_incoming_args_rtx includes the preallocated stack args space. |
---|
| 1032 | It would be no problem to clobber that, but it's on the wrong side |
---|
| 1033 | of the old save area. */ |
---|
| 1034 | { |
---|
| 1035 | rtx dynamic_offset |
---|
| 1036 | = expand_binop (Pmode, sub_optab, virtual_stack_dynamic_rtx, |
---|
| 1037 | stack_pointer_rtx, NULL_RTX, 1, OPTAB_LIB_WIDEN); |
---|
| 1038 | size = expand_binop (Pmode, add_optab, size, dynamic_offset, |
---|
| 1039 | NULL_RTX, 1, OPTAB_LIB_WIDEN); |
---|
| 1040 | } |
---|
| 1041 | #endif /* SETJMP_VIA_SAVE_AREA */ |
---|
| 1042 | |
---|
| 1043 | /* Round the size to a multiple of the required stack alignment. |
---|
| 1044 | Since the stack if presumed to be rounded before this allocation, |
---|
| 1045 | this will maintain the required alignment. |
---|
| 1046 | |
---|
| 1047 | If the stack grows downward, we could save an insn by subtracting |
---|
| 1048 | SIZE from the stack pointer and then aligning the stack pointer. |
---|
| 1049 | The problem with this is that the stack pointer may be unaligned |
---|
| 1050 | between the execution of the subtraction and alignment insns and |
---|
| 1051 | some machines do not allow this. Even on those that do, some |
---|
| 1052 | signal handlers malfunction if a signal should occur between those |
---|
| 1053 | insns. Since this is an extremely rare event, we have no reliable |
---|
| 1054 | way of knowing which systems have this problem. So we avoid even |
---|
| 1055 | momentarily mis-aligning the stack. */ |
---|
| 1056 | |
---|
| 1057 | #ifdef STACK_BOUNDARY |
---|
| 1058 | /* If we added a variable amount to SIZE, |
---|
| 1059 | we can no longer assume it is aligned. */ |
---|
| 1060 | #if !defined (SETJMP_VIA_SAVE_AREA) |
---|
| 1061 | if (MUST_ALIGN || known_align % STACK_BOUNDARY != 0) |
---|
| 1062 | #endif |
---|
| 1063 | size = round_push (size); |
---|
| 1064 | #endif |
---|
| 1065 | |
---|
| 1066 | do_pending_stack_adjust (); |
---|
| 1067 | |
---|
| 1068 | /* Don't use a TARGET that isn't a pseudo. */ |
---|
| 1069 | if (target == 0 || GET_CODE (target) != REG |
---|
| 1070 | || REGNO (target) < FIRST_PSEUDO_REGISTER) |
---|
| 1071 | target = gen_reg_rtx (Pmode); |
---|
| 1072 | |
---|
| 1073 | mark_reg_pointer (target); |
---|
| 1074 | |
---|
| 1075 | #ifndef STACK_GROWS_DOWNWARD |
---|
| 1076 | emit_move_insn (target, virtual_stack_dynamic_rtx); |
---|
| 1077 | #endif |
---|
| 1078 | |
---|
| 1079 | /* Perform the required allocation from the stack. Some systems do |
---|
| 1080 | this differently than simply incrementing/decrementing from the |
---|
| 1081 | stack pointer. */ |
---|
| 1082 | #ifdef HAVE_allocate_stack |
---|
| 1083 | if (HAVE_allocate_stack) |
---|
| 1084 | { |
---|
| 1085 | enum machine_mode mode |
---|
| 1086 | = insn_operand_mode[(int) CODE_FOR_allocate_stack][0]; |
---|
| 1087 | |
---|
| 1088 | size = convert_modes (mode, ptr_mode, size, 1); |
---|
| 1089 | |
---|
| 1090 | if (insn_operand_predicate[(int) CODE_FOR_allocate_stack][0] |
---|
| 1091 | && ! ((*insn_operand_predicate[(int) CODE_FOR_allocate_stack][0]) |
---|
| 1092 | (size, mode))) |
---|
| 1093 | size = copy_to_mode_reg (mode, size); |
---|
| 1094 | |
---|
| 1095 | emit_insn (gen_allocate_stack (size)); |
---|
| 1096 | } |
---|
| 1097 | else |
---|
| 1098 | #endif |
---|
| 1099 | { |
---|
| 1100 | size = convert_modes (Pmode, ptr_mode, size, 1); |
---|
| 1101 | anti_adjust_stack (size); |
---|
| 1102 | } |
---|
| 1103 | |
---|
| 1104 | #ifdef STACK_GROWS_DOWNWARD |
---|
| 1105 | emit_move_insn (target, virtual_stack_dynamic_rtx); |
---|
| 1106 | #endif |
---|
| 1107 | |
---|
| 1108 | if (MUST_ALIGN) |
---|
| 1109 | { |
---|
| 1110 | /* CEIL_DIV_EXPR needs to worry about the addition overflowing, |
---|
| 1111 | but we know it can't. So add ourselves and then do TRUNC_DIV_EXPR. */ |
---|
| 1112 | target = expand_binop (Pmode, add_optab, target, |
---|
| 1113 | GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1), |
---|
| 1114 | NULL_RTX, 1, OPTAB_LIB_WIDEN); |
---|
| 1115 | target = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, target, |
---|
| 1116 | GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT), |
---|
| 1117 | NULL_RTX, 1); |
---|
| 1118 | target = expand_mult (Pmode, target, |
---|
| 1119 | GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT), |
---|
| 1120 | NULL_RTX, 1); |
---|
| 1121 | } |
---|
| 1122 | |
---|
| 1123 | /* Some systems require a particular insn to refer to the stack |
---|
| 1124 | to make the pages exist. */ |
---|
| 1125 | #ifdef HAVE_probe |
---|
| 1126 | if (HAVE_probe) |
---|
| 1127 | emit_insn (gen_probe ()); |
---|
| 1128 | #endif |
---|
| 1129 | |
---|
| 1130 | /* Record the new stack level for nonlocal gotos. */ |
---|
| 1131 | if (nonlocal_goto_handler_slot != 0) |
---|
| 1132 | emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX); |
---|
| 1133 | |
---|
| 1134 | return target; |
---|
| 1135 | } |
---|
| 1136 | |
---|
| 1137 | /* Return an rtx representing the register or memory location |
---|
| 1138 | in which a scalar value of data type VALTYPE |
---|
| 1139 | was returned by a function call to function FUNC. |
---|
| 1140 | FUNC is a FUNCTION_DECL node if the precise function is known, |
---|
| 1141 | otherwise 0. */ |
---|
| 1142 | |
---|
| 1143 | rtx |
---|
| 1144 | hard_function_value (valtype, func) |
---|
| 1145 | tree valtype; |
---|
| 1146 | tree func; |
---|
| 1147 | { |
---|
| 1148 | rtx val = FUNCTION_VALUE (valtype, func); |
---|
| 1149 | if (GET_CODE (val) == REG |
---|
| 1150 | && GET_MODE (val) == BLKmode) |
---|
| 1151 | { |
---|
| 1152 | int bytes = int_size_in_bytes (valtype); |
---|
| 1153 | enum machine_mode tmpmode; |
---|
| 1154 | for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT); |
---|
| 1155 | tmpmode != MAX_MACHINE_MODE; |
---|
| 1156 | tmpmode = GET_MODE_WIDER_MODE (tmpmode)) |
---|
| 1157 | { |
---|
| 1158 | /* Have we found a large enough mode? */ |
---|
| 1159 | if (GET_MODE_SIZE (tmpmode) >= bytes) |
---|
| 1160 | break; |
---|
| 1161 | } |
---|
| 1162 | |
---|
| 1163 | /* No suitable mode found. */ |
---|
| 1164 | if (tmpmode == MAX_MACHINE_MODE) |
---|
| 1165 | abort (); |
---|
| 1166 | |
---|
| 1167 | PUT_MODE (val, tmpmode); |
---|
| 1168 | } |
---|
| 1169 | return val; |
---|
| 1170 | } |
---|
| 1171 | |
---|
| 1172 | /* Return an rtx representing the register or memory location |
---|
| 1173 | in which a scalar value of mode MODE was returned by a library call. */ |
---|
| 1174 | |
---|
| 1175 | rtx |
---|
| 1176 | hard_libcall_value (mode) |
---|
| 1177 | enum machine_mode mode; |
---|
| 1178 | { |
---|
| 1179 | return LIBCALL_VALUE (mode); |
---|
| 1180 | } |
---|
| 1181 | |
---|
| 1182 | /* Look up the tree code for a given rtx code |
---|
| 1183 | to provide the arithmetic operation for REAL_ARITHMETIC. |
---|
| 1184 | The function returns an int because the caller may not know |
---|
| 1185 | what `enum tree_code' means. */ |
---|
| 1186 | |
---|
| 1187 | int |
---|
| 1188 | rtx_to_tree_code (code) |
---|
| 1189 | enum rtx_code code; |
---|
| 1190 | { |
---|
| 1191 | enum tree_code tcode; |
---|
| 1192 | |
---|
| 1193 | switch (code) |
---|
| 1194 | { |
---|
| 1195 | case PLUS: |
---|
| 1196 | tcode = PLUS_EXPR; |
---|
| 1197 | break; |
---|
| 1198 | case MINUS: |
---|
| 1199 | tcode = MINUS_EXPR; |
---|
| 1200 | break; |
---|
| 1201 | case MULT: |
---|
| 1202 | tcode = MULT_EXPR; |
---|
| 1203 | break; |
---|
| 1204 | case DIV: |
---|
| 1205 | tcode = RDIV_EXPR; |
---|
| 1206 | break; |
---|
| 1207 | case SMIN: |
---|
| 1208 | tcode = MIN_EXPR; |
---|
| 1209 | break; |
---|
| 1210 | case SMAX: |
---|
| 1211 | tcode = MAX_EXPR; |
---|
| 1212 | break; |
---|
| 1213 | default: |
---|
| 1214 | tcode = LAST_AND_UNUSED_TREE_CODE; |
---|
| 1215 | break; |
---|
| 1216 | } |
---|
| 1217 | return ((int) tcode); |
---|
| 1218 | } |
---|