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annotate gcc/compare-elim.c @ 158:494b0b89df80 default tip

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author Shinji KONO <kono@ie.u-ryukyu.ac.jp>
date Mon, 25 May 2020 18:13:55 +0900
parents 1830386684a0
children
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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1 /* Post-reload compare elimination.
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2 Copyright (C) 2010-2020 Free Software Foundation, Inc.
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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3
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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4 This file is part of GCC.
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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5
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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6 GCC is free software; you can redistribute it and/or modify it under
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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7 the terms of the GNU General Public License as published by the Free
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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8 Software Foundation; either version 3, or (at your option) any later
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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9 version.
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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10
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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14 for more details.
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15
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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16 You should have received a copy of the GNU General Public License
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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17 along with GCC; see the file COPYING3. If not see
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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18 <http://www.gnu.org/licenses/>. */
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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19
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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20 /* There is a set of targets whose general-purpose move or addition
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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21 instructions clobber the flags. These targets cannot split their
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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22 CBRANCH/CSTORE etc patterns before reload is complete, lest reload
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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23 itself insert these instructions in between the flags setter and user.
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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24 Because these targets cannot split the compare from the use, they
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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25 cannot make use of the comparison elimination offered by the combine pass.
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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26
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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27 This is a small pass intended to provide comparison elimination similar to
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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28 what is available via NOTICE_UPDATE_CC for cc0 targets. This should help
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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29 encourage cc0 targets to convert to an explicit post-reload representation
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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30 of the flags.
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31
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32 This pass assumes:
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33
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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34 (0) CBRANCH/CSTORE etc have been split in pass_split_after_reload.
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35
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36 (1) All comparison patterns are represented as
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37
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38 [(set (reg:CC) (compare:CC (reg) (reg_or_immediate)))]
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39
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40 (2) All insn patterns that modify the flags are represented as
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41
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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42 [(set (reg) (operation)
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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43 (clobber (reg:CC))]
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44
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45 (3) If an insn of form (2) can usefully set the flags, there is
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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46 another pattern of the form
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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47
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48 [(set (reg:CCM) (compare:CCM (operation) (immediate)))
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49 (set (reg) (operation)]
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50
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51 The mode CCM will be chosen as if by SELECT_CC_MODE.
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52
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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53 Note that unlike NOTICE_UPDATE_CC, we do not handle memory operands.
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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54 This could be handled as a future enhancement.
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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55 */
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56
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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57 #include "config.h"
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58 #include "system.h"
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59 #include "coretypes.h"
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60 #include "backend.h"
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61 #include "target.h"
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62 #include "rtl.h"
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63 #include "df.h"
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64 #include "memmodel.h"
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65 #include "tm_p.h"
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66 #include "insn-config.h"
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67 #include "recog.h"
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68 #include "emit-rtl.h"
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69 #include "cfgrtl.h"
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70 #include "tree-pass.h"
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71 #include "domwalk.h"
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72
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73
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74 /* These structures describe a comparison and how it is used. */
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75
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76 /* The choice of maximum 3 uses comes from wanting to eliminate the two
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77 duplicate compares from a three-way branch on the sign of a value.
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78 This is also sufficient to eliminate the duplicate compare against the
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79 high-part of a double-word comparison. */
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80 #define MAX_CMP_USE 3
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81
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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82 struct comparison_use
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83 {
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84 /* The instruction in which the result of the compare is used. */
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85 rtx_insn *insn;
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86 /* The location of the flags register within the use. */
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87 rtx *loc;
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88 /* The comparison code applied against the flags register. */
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89 enum rtx_code code;
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90 };
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91
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92 struct comparison
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93 {
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94 /* The comparison instruction. */
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95 rtx_insn *insn;
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96
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97 /* The insn prior to the comparison insn that clobbers the flags. */
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98 rtx_insn *prev_clobber;
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99
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100 /* The insn prior to the comparison insn that sets in_a REG. */
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101 rtx_insn *in_a_setter;
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102
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103 /* The two values being compared. These will be either REGs or
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104 constants. */
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105 rtx in_a, in_b;
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106
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107 /* The REG_EH_REGION of the comparison. */
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108 rtx eh_note;
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109
68
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110 /* Information about how this comparison is used. */
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111 struct comparison_use uses[MAX_CMP_USE];
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112
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113 /* The original CC_MODE for this comparison. */
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114 machine_mode orig_mode;
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115
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116 /* The number of uses identified for this comparison. */
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117 unsigned short n_uses;
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118
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119 /* True if not all uses of this comparison have been identified.
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120 This can happen either for overflowing the array above, or if
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121 the flags register is used in some unusual context. */
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122 bool missing_uses;
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123
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124 /* True if its inputs are still valid at the end of the block. */
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125 bool inputs_valid;
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126
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127 /* Whether IN_A is wrapped in a NOT before being compared. */
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128 bool not_in_a;
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129 };
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130
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131 static vec<comparison *> all_compares;
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132
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133 /* Return whether X is a NOT unary expression. */
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134
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135 static bool
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136 is_not (rtx x)
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137 {
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138 return GET_CODE (x) == NOT;
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139 }
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140
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141 /* Strip a NOT unary expression around X, if any. */
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142
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143 static rtx
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144 strip_not (rtx x)
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diff changeset
145 {
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
146 if (is_not (x))
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
147 return XEXP (x, 0);
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
148
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
149 return x;
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
150 }
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
151
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
152 /* Look for a "conforming" comparison, as defined above. If valid, return
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
153 the rtx for the COMPARE itself. */
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
154
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
155 static rtx
111
kono
parents: 68
diff changeset
156 conforming_compare (rtx_insn *insn)
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
157 {
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
158 rtx set, src, dest;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
159
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
160 set = single_set (insn);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
161 if (set == NULL)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
162 return NULL;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
163
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
164 src = SET_SRC (set);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
165 if (GET_CODE (src) != COMPARE)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
166 return NULL;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
167
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
168 dest = SET_DEST (set);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
169 if (!REG_P (dest) || REGNO (dest) != targetm.flags_regnum)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
170 return NULL;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
171
145
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
172 if (!REG_P (strip_not (XEXP (src, 0))))
111
kono
parents: 68
diff changeset
173 return NULL;
kono
parents: 68
diff changeset
174
kono
parents: 68
diff changeset
175 if (CONSTANT_P (XEXP (src, 1)) || REG_P (XEXP (src, 1)))
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
176 return src;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
177
111
kono
parents: 68
diff changeset
178 if (GET_CODE (XEXP (src, 1)) == UNSPEC)
kono
parents: 68
diff changeset
179 {
kono
parents: 68
diff changeset
180 for (int i = 0; i < XVECLEN (XEXP (src, 1), 0); i++)
kono
parents: 68
diff changeset
181 if (!REG_P (XVECEXP (XEXP (src, 1), 0, i)))
kono
parents: 68
diff changeset
182 return NULL;
kono
parents: 68
diff changeset
183 return src;
kono
parents: 68
diff changeset
184 }
kono
parents: 68
diff changeset
185
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
186 return NULL;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
187 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
188
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
189 /* Look for a pattern of the "correct" form for an insn with a flags clobber
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
190 for which we may be able to eliminate a compare later. We're not looking
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
191 to validate any inputs at this time, merely see that the basic shape is
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
192 correct. The term "arithmetic" may be somewhat misleading... */
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
193
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
194 static bool
111
kono
parents: 68
diff changeset
195 arithmetic_flags_clobber_p (rtx_insn *insn)
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
196 {
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
197 rtx pat, x;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
198
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
199 if (!NONJUMP_INSN_P (insn))
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
200 return false;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
201 pat = PATTERN (insn);
111
kono
parents: 68
diff changeset
202 if (asm_noperands (pat) >= 0)
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
203 return false;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
204
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
205 if (GET_CODE (pat) == PARALLEL && XVECLEN (pat, 0) == 2)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
206 {
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
207 x = XVECEXP (pat, 0, 0);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
208 if (GET_CODE (x) != SET)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
209 return false;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
210 x = SET_DEST (x);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
211 if (!REG_P (x))
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
212 return false;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
213
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
214 x = XVECEXP (pat, 0, 1);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
215 if (GET_CODE (x) == CLOBBER)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
216 {
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
217 x = XEXP (x, 0);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
218 if (REG_P (x) && REGNO (x) == targetm.flags_regnum)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
219 return true;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
220 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
221 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
222
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
223 return false;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
224 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
225
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
226 /* Look for uses of FLAGS in INSN. If we find one we can analyze, record
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
227 it in CMP; otherwise indicate that we've missed a use. */
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
228
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
229 static void
111
kono
parents: 68
diff changeset
230 find_flags_uses_in_insn (struct comparison *cmp, rtx_insn *insn)
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
231 {
111
kono
parents: 68
diff changeset
232 df_ref use;
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
233
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
234 /* If we've already lost track of uses, don't bother collecting more. */
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
235 if (cmp->missing_uses)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
236 return;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
237
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
238 /* Find a USE of the flags register. */
111
kono
parents: 68
diff changeset
239 FOR_EACH_INSN_USE (use, insn)
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
240 if (DF_REF_REGNO (use) == targetm.flags_regnum)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
241 {
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
242 rtx x, *loc;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
243
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
244 /* If this is an unusual use, quit. */
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
245 if (DF_REF_TYPE (use) != DF_REF_REG_USE)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
246 goto fail;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
247
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
248 /* If we've run out of slots to record uses, quit. */
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
249 if (cmp->n_uses == MAX_CMP_USE)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
250 goto fail;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
251
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
252 /* Unfortunately the location of the flags register, while present
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
253 in the reference structure, doesn't help. We need to find the
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
254 comparison code that is outer to the actual flags use. */
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
255 loc = DF_REF_LOC (use);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
256 x = PATTERN (insn);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
257 if (GET_CODE (x) == PARALLEL)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
258 x = XVECEXP (x, 0, 0);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
259 x = SET_SRC (x);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
260 if (GET_CODE (x) == IF_THEN_ELSE)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
261 x = XEXP (x, 0);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
262 if (COMPARISON_P (x)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
263 && loc == &XEXP (x, 0)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
264 && XEXP (x, 1) == const0_rtx)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
265 {
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
266 /* We've found a use of the flags that we understand. */
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
267 struct comparison_use *cuse = &cmp->uses[cmp->n_uses++];
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
268 cuse->insn = insn;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
269 cuse->loc = loc;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
270 cuse->code = GET_CODE (x);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
271 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
272 else
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
273 goto fail;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
274 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
275 return;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
276
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
277 fail:
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
278 /* We failed to recognize this use of the flags register. */
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
279 cmp->missing_uses = true;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
280 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
281
111
kono
parents: 68
diff changeset
282 class find_comparison_dom_walker : public dom_walker
kono
parents: 68
diff changeset
283 {
kono
parents: 68
diff changeset
284 public:
kono
parents: 68
diff changeset
285 find_comparison_dom_walker (cdi_direction direction)
kono
parents: 68
diff changeset
286 : dom_walker (direction) {}
kono
parents: 68
diff changeset
287
kono
parents: 68
diff changeset
288 virtual edge before_dom_children (basic_block);
kono
parents: 68
diff changeset
289 };
kono
parents: 68
diff changeset
290
kono
parents: 68
diff changeset
291 /* Return true if conforming COMPARE with EH_NOTE is redundant with comparison
kono
parents: 68
diff changeset
292 CMP and can thus be eliminated. */
kono
parents: 68
diff changeset
293
kono
parents: 68
diff changeset
294 static bool
kono
parents: 68
diff changeset
295 can_eliminate_compare (rtx compare, rtx eh_note, struct comparison *cmp)
kono
parents: 68
diff changeset
296 {
kono
parents: 68
diff changeset
297 /* Take care that it's in the same EH region. */
kono
parents: 68
diff changeset
298 if (cfun->can_throw_non_call_exceptions
kono
parents: 68
diff changeset
299 && !rtx_equal_p (eh_note, cmp->eh_note))
kono
parents: 68
diff changeset
300 return false;
kono
parents: 68
diff changeset
301
kono
parents: 68
diff changeset
302 /* Make sure the compare is redundant with the previous. */
145
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
303 if (!rtx_equal_p (strip_not (XEXP (compare, 0)), cmp->in_a)
111
kono
parents: 68
diff changeset
304 || !rtx_equal_p (XEXP (compare, 1), cmp->in_b))
kono
parents: 68
diff changeset
305 return false;
kono
parents: 68
diff changeset
306
145
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
307 if (is_not (XEXP (compare, 0)) != cmp->not_in_a)
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
308 return false;
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
309
111
kono
parents: 68
diff changeset
310 /* New mode must be compatible with the previous compare mode. */
kono
parents: 68
diff changeset
311 machine_mode new_mode
kono
parents: 68
diff changeset
312 = targetm.cc_modes_compatible (GET_MODE (compare), cmp->orig_mode);
kono
parents: 68
diff changeset
313
kono
parents: 68
diff changeset
314 if (new_mode == VOIDmode)
kono
parents: 68
diff changeset
315 return false;
kono
parents: 68
diff changeset
316
kono
parents: 68
diff changeset
317 if (cmp->orig_mode != new_mode)
kono
parents: 68
diff changeset
318 {
kono
parents: 68
diff changeset
319 /* Generate new comparison for substitution. */
kono
parents: 68
diff changeset
320 rtx flags = gen_rtx_REG (new_mode, targetm.flags_regnum);
kono
parents: 68
diff changeset
321 rtx x = gen_rtx_COMPARE (new_mode, cmp->in_a, cmp->in_b);
kono
parents: 68
diff changeset
322 x = gen_rtx_SET (flags, x);
kono
parents: 68
diff changeset
323
kono
parents: 68
diff changeset
324 if (!validate_change (cmp->insn, &PATTERN (cmp->insn), x, false))
kono
parents: 68
diff changeset
325 return false;
kono
parents: 68
diff changeset
326
kono
parents: 68
diff changeset
327 cmp->orig_mode = new_mode;
kono
parents: 68
diff changeset
328 }
kono
parents: 68
diff changeset
329
kono
parents: 68
diff changeset
330 return true;
kono
parents: 68
diff changeset
331 }
kono
parents: 68
diff changeset
332
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
333 /* Identify comparison instructions within BB. If the flags from the last
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
334 compare in the BB is live at the end of the block, install the compare
111
kono
parents: 68
diff changeset
335 in BB->AUX. Called via dom_walker.walk (). */
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
336
111
kono
parents: 68
diff changeset
337 edge
kono
parents: 68
diff changeset
338 find_comparison_dom_walker::before_dom_children (basic_block bb)
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
339 {
131
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
340 rtx_insn *insn, *next;
111
kono
parents: 68
diff changeset
341 bool need_purge = false;
131
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
342 rtx_insn *last_setter[FIRST_PSEUDO_REGISTER];
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
343
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
344 /* The last comparison that was made. Will be reset to NULL
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
345 once the flags are clobbered. */
131
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
346 struct comparison *last_cmp = NULL;
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
347
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
348 /* True iff the last comparison has not been clobbered, nor
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
349 have its inputs. Used to eliminate duplicate compares. */
131
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
350 bool last_cmp_valid = false;
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
351
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
352 /* The last insn that clobbered the flags, if that insn is of
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
353 a form that may be valid for eliminating a following compare.
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
354 To be reset to NULL once the flags are set otherwise. */
131
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
355 rtx_insn *last_clobber = NULL;
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
356
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
357 /* Propagate the last live comparison throughout the extended basic block. */
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
358 if (single_pred_p (bb))
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
359 {
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
360 last_cmp = (struct comparison *) single_pred (bb)->aux;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
361 if (last_cmp)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
362 last_cmp_valid = last_cmp->inputs_valid;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
363 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
364
131
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
365 memset (last_setter, 0, sizeof (last_setter));
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
366 for (insn = BB_HEAD (bb); insn; insn = next)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
367 {
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
368 rtx src;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
369
111
kono
parents: 68
diff changeset
370 next = (insn == BB_END (bb) ? NULL : NEXT_INSN (insn));
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
371 if (!NONDEBUG_INSN_P (insn))
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
372 continue;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
373
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
374 src = conforming_compare (insn);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
375 if (src)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
376 {
111
kono
parents: 68
diff changeset
377 rtx eh_note = NULL;
kono
parents: 68
diff changeset
378
kono
parents: 68
diff changeset
379 if (cfun->can_throw_non_call_exceptions)
kono
parents: 68
diff changeset
380 eh_note = find_reg_note (insn, REG_EH_REGION, NULL);
kono
parents: 68
diff changeset
381
kono
parents: 68
diff changeset
382 if (last_cmp_valid && can_eliminate_compare (src, eh_note, last_cmp))
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
383 {
111
kono
parents: 68
diff changeset
384 if (eh_note)
kono
parents: 68
diff changeset
385 need_purge = true;
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
386 delete_insn (insn);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
387 continue;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
388 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
389
111
kono
parents: 68
diff changeset
390 last_cmp = XCNEW (struct comparison);
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
391 last_cmp->insn = insn;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
392 last_cmp->prev_clobber = last_clobber;
145
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
393 last_cmp->in_a = strip_not (XEXP (src, 0));
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
394 last_cmp->in_b = XEXP (src, 1);
145
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
395 last_cmp->not_in_a = is_not (XEXP (src, 0));
111
kono
parents: 68
diff changeset
396 last_cmp->eh_note = eh_note;
kono
parents: 68
diff changeset
397 last_cmp->orig_mode = GET_MODE (src);
131
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
398 if (last_cmp->in_b == const0_rtx
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
399 && last_setter[REGNO (last_cmp->in_a)])
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
400 {
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
401 rtx set = single_set (last_setter[REGNO (last_cmp->in_a)]);
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
402 if (set && rtx_equal_p (SET_DEST (set), last_cmp->in_a))
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
403 last_cmp->in_a_setter = last_setter[REGNO (last_cmp->in_a)];
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
404 }
111
kono
parents: 68
diff changeset
405 all_compares.safe_push (last_cmp);
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
406
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
407 /* It's unusual, but be prepared for comparison patterns that
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
408 also clobber an input, or perhaps a scratch. */
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
409 last_clobber = NULL;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
410 last_cmp_valid = true;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
411 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
412
111
kono
parents: 68
diff changeset
413 else
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
414 {
111
kono
parents: 68
diff changeset
415 /* Notice if this instruction uses the flags register. */
kono
parents: 68
diff changeset
416 if (last_cmp)
kono
parents: 68
diff changeset
417 find_flags_uses_in_insn (last_cmp, insn);
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
418
111
kono
parents: 68
diff changeset
419 /* Notice if this instruction kills the flags register. */
131
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
420 df_ref def;
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
421 FOR_EACH_INSN_DEF (def, insn)
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
422 if (DF_REF_REGNO (def) == targetm.flags_regnum)
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
423 {
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
424 /* See if this insn could be the "clobber" that eliminates
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
425 a future comparison. */
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
426 last_clobber = (arithmetic_flags_clobber_p (insn)
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
427 ? insn : NULL);
111
kono
parents: 68
diff changeset
428
131
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
429 /* In either case, the previous compare is no longer valid. */
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
430 last_cmp = NULL;
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
431 last_cmp_valid = false;
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
432 break;
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
433 }
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
434 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
435
131
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
436 /* Notice if any of the inputs to the comparison have changed
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
437 and remember last insn that sets each register. */
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
438 df_ref def;
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
439 FOR_EACH_INSN_DEF (def, insn)
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
440 {
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
441 if (last_cmp_valid
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
442 && (DF_REF_REGNO (def) == REGNO (last_cmp->in_a)
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
443 || (REG_P (last_cmp->in_b)
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
444 && DF_REF_REGNO (def) == REGNO (last_cmp->in_b))))
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
445 last_cmp_valid = false;
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
446 last_setter[DF_REF_REGNO (def)] = insn;
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
447 }
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
448 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
449
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
450 /* Remember the live comparison for subsequent members of
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
451 the extended basic block. */
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
452 if (last_cmp)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
453 {
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
454 bb->aux = last_cmp;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
455 last_cmp->inputs_valid = last_cmp_valid;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
456
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
457 /* Look to see if the flags register is live outgoing here, and
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
458 incoming to any successor not part of the extended basic block. */
111
kono
parents: 68
diff changeset
459 if (bitmap_bit_p (df_get_live_out (bb), targetm.flags_regnum))
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
460 {
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
461 edge e;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
462 edge_iterator ei;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
463
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
464 FOR_EACH_EDGE (e, ei, bb->succs)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
465 {
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
466 basic_block dest = e->dest;
111
kono
parents: 68
diff changeset
467 if (bitmap_bit_p (df_get_live_in (bb), targetm.flags_regnum)
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
468 && !single_pred_p (dest))
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
469 {
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
470 last_cmp->missing_uses = true;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
471 break;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
472 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
473 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
474 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
475 }
111
kono
parents: 68
diff changeset
476
kono
parents: 68
diff changeset
477 /* If we deleted a compare with a REG_EH_REGION note, we may need to
kono
parents: 68
diff changeset
478 remove EH edges. */
kono
parents: 68
diff changeset
479 if (need_purge)
kono
parents: 68
diff changeset
480 purge_dead_edges (bb);
kono
parents: 68
diff changeset
481
kono
parents: 68
diff changeset
482 return NULL;
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
483 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
484
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
485 /* Find all comparisons in the function. */
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
486
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
487 static void
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
488 find_comparisons (void)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
489 {
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
490 calculate_dominance_info (CDI_DOMINATORS);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
491
111
kono
parents: 68
diff changeset
492 find_comparison_dom_walker (CDI_DOMINATORS)
kono
parents: 68
diff changeset
493 .walk (cfun->cfg->x_entry_block_ptr);
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
494
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
495 clear_aux_for_blocks ();
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
496 free_dominance_info (CDI_DOMINATORS);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
497 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
498
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
499 /* Select an alternate CC_MODE for a comparison insn comparing A and B.
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
500 Note that inputs are almost certainly different than the IN_A and IN_B
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
501 stored in CMP -- we're called while attempting to eliminate the compare
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
502 after all. Return the new FLAGS rtx if successful, else return NULL.
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
503 Note that this function may start a change group. */
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
504
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
505 static rtx
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
506 maybe_select_cc_mode (struct comparison *cmp, rtx a ATTRIBUTE_UNUSED,
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
507 rtx b ATTRIBUTE_UNUSED)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
508 {
111
kono
parents: 68
diff changeset
509 machine_mode sel_mode;
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
510 const int n = cmp->n_uses;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
511 rtx flags = NULL;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
512
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
513 #ifndef SELECT_CC_MODE
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
514 /* Minimize code differences when this target macro is undefined. */
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
515 return NULL;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
516 #define SELECT_CC_MODE(A,B,C) (gcc_unreachable (), VOIDmode)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
517 #endif
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
518
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
519 /* If we don't have access to all of the uses, we can't validate. */
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
520 if (cmp->missing_uses || n == 0)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
521 return NULL;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
522
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
523 /* Find a new mode that works for all of the uses. Special case the
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
524 common case of exactly one use. */
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
525 if (n == 1)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
526 {
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
527 sel_mode = SELECT_CC_MODE (cmp->uses[0].code, a, b);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
528 if (sel_mode != cmp->orig_mode)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
529 {
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
530 flags = gen_rtx_REG (sel_mode, targetm.flags_regnum);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
531 validate_change (cmp->uses[0].insn, cmp->uses[0].loc, flags, true);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
532 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
533 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
534 else
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
535 {
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
536 int i;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
537
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
538 sel_mode = SELECT_CC_MODE (cmp->uses[0].code, a, b);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
539 for (i = 1; i < n; ++i)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
540 {
111
kono
parents: 68
diff changeset
541 machine_mode new_mode = SELECT_CC_MODE (cmp->uses[i].code, a, b);
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
542 if (new_mode != sel_mode)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
543 {
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
544 sel_mode = targetm.cc_modes_compatible (sel_mode, new_mode);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
545 if (sel_mode == VOIDmode)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
546 return NULL;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
547 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
548 }
111
kono
parents: 68
diff changeset
549
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
550 if (sel_mode != cmp->orig_mode)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
551 {
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
552 flags = gen_rtx_REG (sel_mode, targetm.flags_regnum);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
553 for (i = 0; i < n; ++i)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
554 validate_change (cmp->uses[i].insn, cmp->uses[i].loc, flags, true);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
555 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
556 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
557
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
558 return flags;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
559 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
560
111
kono
parents: 68
diff changeset
561 /* Return a register RTX holding the same value at START as REG at END, or
kono
parents: 68
diff changeset
562 NULL_RTX if there is none. */
kono
parents: 68
diff changeset
563
kono
parents: 68
diff changeset
564 static rtx
kono
parents: 68
diff changeset
565 equivalent_reg_at_start (rtx reg, rtx_insn *end, rtx_insn *start)
kono
parents: 68
diff changeset
566 {
kono
parents: 68
diff changeset
567 machine_mode orig_mode = GET_MODE (reg);
kono
parents: 68
diff changeset
568 rtx_insn *bb_head = BB_HEAD (BLOCK_FOR_INSN (end));
kono
parents: 68
diff changeset
569
kono
parents: 68
diff changeset
570 for (rtx_insn *insn = PREV_INSN (end);
kono
parents: 68
diff changeset
571 insn != start;
kono
parents: 68
diff changeset
572 insn = PREV_INSN (insn))
kono
parents: 68
diff changeset
573 {
kono
parents: 68
diff changeset
574 const int abnormal_flags
kono
parents: 68
diff changeset
575 = (DF_REF_CONDITIONAL | DF_REF_PARTIAL | DF_REF_MAY_CLOBBER
kono
parents: 68
diff changeset
576 | DF_REF_MUST_CLOBBER | DF_REF_SIGN_EXTRACT
kono
parents: 68
diff changeset
577 | DF_REF_ZERO_EXTRACT | DF_REF_STRICT_LOW_PART
kono
parents: 68
diff changeset
578 | DF_REF_PRE_POST_MODIFY);
kono
parents: 68
diff changeset
579 df_ref def;
kono
parents: 68
diff changeset
580
kono
parents: 68
diff changeset
581 /* Note that the BB_HEAD is always either a note or a label, but in
kono
parents: 68
diff changeset
582 any case it means that REG is defined outside the block. */
kono
parents: 68
diff changeset
583 if (insn == bb_head)
kono
parents: 68
diff changeset
584 return NULL_RTX;
kono
parents: 68
diff changeset
585 if (NOTE_P (insn) || DEBUG_INSN_P (insn))
kono
parents: 68
diff changeset
586 continue;
kono
parents: 68
diff changeset
587
kono
parents: 68
diff changeset
588 /* Find a possible def of REG in INSN. */
kono
parents: 68
diff changeset
589 FOR_EACH_INSN_DEF (def, insn)
kono
parents: 68
diff changeset
590 if (DF_REF_REGNO (def) == REGNO (reg))
kono
parents: 68
diff changeset
591 break;
kono
parents: 68
diff changeset
592
kono
parents: 68
diff changeset
593 /* No definitions of REG; continue searching. */
kono
parents: 68
diff changeset
594 if (def == NULL)
kono
parents: 68
diff changeset
595 continue;
kono
parents: 68
diff changeset
596
kono
parents: 68
diff changeset
597 /* Bail if this is not a totally normal set of REG. */
kono
parents: 68
diff changeset
598 if (DF_REF_IS_ARTIFICIAL (def))
kono
parents: 68
diff changeset
599 return NULL_RTX;
kono
parents: 68
diff changeset
600 if (DF_REF_FLAGS (def) & abnormal_flags)
kono
parents: 68
diff changeset
601 return NULL_RTX;
kono
parents: 68
diff changeset
602
kono
parents: 68
diff changeset
603 /* We've found an insn between the compare and the clobber that sets
kono
parents: 68
diff changeset
604 REG. Given that pass_cprop_hardreg has not yet run, we still find
kono
parents: 68
diff changeset
605 situations in which we can usefully look through a copy insn. */
kono
parents: 68
diff changeset
606 rtx x = single_set (insn);
kono
parents: 68
diff changeset
607 if (x == NULL_RTX)
kono
parents: 68
diff changeset
608 return NULL_RTX;
kono
parents: 68
diff changeset
609 reg = SET_SRC (x);
kono
parents: 68
diff changeset
610 if (!REG_P (reg))
kono
parents: 68
diff changeset
611 return NULL_RTX;
kono
parents: 68
diff changeset
612 }
kono
parents: 68
diff changeset
613
kono
parents: 68
diff changeset
614 if (GET_MODE (reg) != orig_mode)
kono
parents: 68
diff changeset
615 return NULL_RTX;
kono
parents: 68
diff changeset
616
kono
parents: 68
diff changeset
617 return reg;
kono
parents: 68
diff changeset
618 }
kono
parents: 68
diff changeset
619
kono
parents: 68
diff changeset
620 /* Return true if it is okay to merge the comparison CMP_INSN with
kono
parents: 68
diff changeset
621 the instruction ARITH_INSN. Both instructions are assumed to be in the
kono
parents: 68
diff changeset
622 same basic block with ARITH_INSN appearing before CMP_INSN. This checks
kono
parents: 68
diff changeset
623 that there are no uses or defs of the condition flags or control flow
kono
parents: 68
diff changeset
624 changes between the two instructions. */
kono
parents: 68
diff changeset
625
kono
parents: 68
diff changeset
626 static bool
kono
parents: 68
diff changeset
627 can_merge_compare_into_arith (rtx_insn *cmp_insn, rtx_insn *arith_insn)
kono
parents: 68
diff changeset
628 {
kono
parents: 68
diff changeset
629 for (rtx_insn *insn = PREV_INSN (cmp_insn);
kono
parents: 68
diff changeset
630 insn && insn != arith_insn;
kono
parents: 68
diff changeset
631 insn = PREV_INSN (insn))
kono
parents: 68
diff changeset
632 {
kono
parents: 68
diff changeset
633 if (!NONDEBUG_INSN_P (insn))
kono
parents: 68
diff changeset
634 continue;
kono
parents: 68
diff changeset
635 /* Bail if there are jumps or calls in between. */
kono
parents: 68
diff changeset
636 if (!NONJUMP_INSN_P (insn))
kono
parents: 68
diff changeset
637 return false;
kono
parents: 68
diff changeset
638
kono
parents: 68
diff changeset
639 /* Bail on old-style asm statements because they lack
kono
parents: 68
diff changeset
640 data flow information. */
kono
parents: 68
diff changeset
641 if (GET_CODE (PATTERN (insn)) == ASM_INPUT)
kono
parents: 68
diff changeset
642 return false;
kono
parents: 68
diff changeset
643
kono
parents: 68
diff changeset
644 df_ref ref;
kono
parents: 68
diff changeset
645 /* Find a USE of the flags register. */
kono
parents: 68
diff changeset
646 FOR_EACH_INSN_USE (ref, insn)
kono
parents: 68
diff changeset
647 if (DF_REF_REGNO (ref) == targetm.flags_regnum)
kono
parents: 68
diff changeset
648 return false;
kono
parents: 68
diff changeset
649
kono
parents: 68
diff changeset
650 /* Find a DEF of the flags register. */
kono
parents: 68
diff changeset
651 FOR_EACH_INSN_DEF (ref, insn)
kono
parents: 68
diff changeset
652 if (DF_REF_REGNO (ref) == targetm.flags_regnum)
kono
parents: 68
diff changeset
653 return false;
kono
parents: 68
diff changeset
654 }
kono
parents: 68
diff changeset
655 return true;
kono
parents: 68
diff changeset
656 }
kono
parents: 68
diff changeset
657
kono
parents: 68
diff changeset
658 /* Given two SET expressions, SET_A and SET_B determine whether they form
kono
parents: 68
diff changeset
659 a recognizable pattern when emitted in parallel. Return that parallel
kono
parents: 68
diff changeset
660 if so. Otherwise return NULL. */
kono
parents: 68
diff changeset
661
kono
parents: 68
diff changeset
662 static rtx
kono
parents: 68
diff changeset
663 try_validate_parallel (rtx set_a, rtx set_b)
kono
parents: 68
diff changeset
664 {
131
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
665 rtx par = gen_rtx_PARALLEL (VOIDmode, gen_rtvec (2, set_a, set_b));
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
666 rtx_insn *insn = make_insn_raw (par);
111
kono
parents: 68
diff changeset
667
131
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
668 if (insn_invalid_p (insn, false))
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
669 {
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
670 crtl->emit.x_cur_insn_uid--;
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
671 return NULL_RTX;
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
672 }
111
kono
parents: 68
diff changeset
673
131
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
674 SET_PREV_INSN (insn) = NULL_RTX;
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
675 SET_NEXT_INSN (insn) = NULL_RTX;
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
676 INSN_LOCATION (insn) = 0;
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
677 return insn;
111
kono
parents: 68
diff changeset
678 }
kono
parents: 68
diff changeset
679
kono
parents: 68
diff changeset
680 /* For a comparison instruction described by CMP check if it compares a
kono
parents: 68
diff changeset
681 register with zero i.e. it is of the form CC := CMP R1, 0.
kono
parents: 68
diff changeset
682 If it is, find the instruction defining R1 (say I1) and try to create a
kono
parents: 68
diff changeset
683 PARALLEL consisting of I1 and the comparison, representing a flag-setting
kono
parents: 68
diff changeset
684 arithmetic instruction. Example:
kono
parents: 68
diff changeset
685 I1: R1 := R2 + R3
kono
parents: 68
diff changeset
686 <instructions that don't read the condition register>
kono
parents: 68
diff changeset
687 I2: CC := CMP R1 0
kono
parents: 68
diff changeset
688 I2 can be merged with I1 into:
131
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
689 I1: { CC := CMP (R2 + R3) 0 ; R1 := R2 + R3 }
111
kono
parents: 68
diff changeset
690 This catches cases where R1 is used between I1 and I2 and therefore
kono
parents: 68
diff changeset
691 combine and other RTL optimisations will not try to propagate it into
kono
parents: 68
diff changeset
692 I2. Return true if we succeeded in merging CMP. */
kono
parents: 68
diff changeset
693
kono
parents: 68
diff changeset
694 static bool
kono
parents: 68
diff changeset
695 try_merge_compare (struct comparison *cmp)
kono
parents: 68
diff changeset
696 {
kono
parents: 68
diff changeset
697 rtx_insn *cmp_insn = cmp->insn;
kono
parents: 68
diff changeset
698
131
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
699 if (cmp->in_b != const0_rtx || cmp->in_a_setter == NULL)
111
kono
parents: 68
diff changeset
700 return false;
kono
parents: 68
diff changeset
701 rtx in_a = cmp->in_a;
kono
parents: 68
diff changeset
702 df_ref use;
kono
parents: 68
diff changeset
703
kono
parents: 68
diff changeset
704 FOR_EACH_INSN_USE (use, cmp_insn)
kono
parents: 68
diff changeset
705 if (DF_REF_REGNO (use) == REGNO (in_a))
kono
parents: 68
diff changeset
706 break;
kono
parents: 68
diff changeset
707 if (!use)
kono
parents: 68
diff changeset
708 return false;
kono
parents: 68
diff changeset
709
131
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
710 rtx_insn *def_insn = cmp->in_a_setter;
111
kono
parents: 68
diff changeset
711 rtx set = single_set (def_insn);
kono
parents: 68
diff changeset
712 if (!set)
kono
parents: 68
diff changeset
713 return false;
kono
parents: 68
diff changeset
714
kono
parents: 68
diff changeset
715 if (!can_merge_compare_into_arith (cmp_insn, def_insn))
kono
parents: 68
diff changeset
716 return false;
kono
parents: 68
diff changeset
717
kono
parents: 68
diff changeset
718 rtx src = SET_SRC (set);
131
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
719
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
720 /* If the source uses addressing modes with side effects, we can't
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
721 do the merge because we'd end up with a PARALLEL that has two
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
722 instances of that side effect in it. */
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
723 if (side_effects_p (src))
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
724 return false;
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
725
111
kono
parents: 68
diff changeset
726 rtx flags = maybe_select_cc_mode (cmp, src, CONST0_RTX (GET_MODE (src)));
kono
parents: 68
diff changeset
727 if (!flags)
kono
parents: 68
diff changeset
728 {
kono
parents: 68
diff changeset
729 /* We may already have a change group going through maybe_select_cc_mode.
kono
parents: 68
diff changeset
730 Discard it properly. */
kono
parents: 68
diff changeset
731 cancel_changes (0);
kono
parents: 68
diff changeset
732 return false;
kono
parents: 68
diff changeset
733 }
kono
parents: 68
diff changeset
734
kono
parents: 68
diff changeset
735 rtx flag_set
kono
parents: 68
diff changeset
736 = gen_rtx_SET (flags, gen_rtx_COMPARE (GET_MODE (flags),
kono
parents: 68
diff changeset
737 copy_rtx (src),
kono
parents: 68
diff changeset
738 CONST0_RTX (GET_MODE (src))));
kono
parents: 68
diff changeset
739 rtx arith_set = copy_rtx (PATTERN (def_insn));
kono
parents: 68
diff changeset
740 rtx par = try_validate_parallel (flag_set, arith_set);
kono
parents: 68
diff changeset
741 if (!par)
kono
parents: 68
diff changeset
742 {
kono
parents: 68
diff changeset
743 /* We may already have a change group going through maybe_select_cc_mode.
kono
parents: 68
diff changeset
744 Discard it properly. */
kono
parents: 68
diff changeset
745 cancel_changes (0);
kono
parents: 68
diff changeset
746 return false;
kono
parents: 68
diff changeset
747 }
kono
parents: 68
diff changeset
748 if (!apply_change_group ())
kono
parents: 68
diff changeset
749 return false;
kono
parents: 68
diff changeset
750 emit_insn_after (par, def_insn);
kono
parents: 68
diff changeset
751 delete_insn (def_insn);
kono
parents: 68
diff changeset
752 delete_insn (cmp->insn);
kono
parents: 68
diff changeset
753 return true;
kono
parents: 68
diff changeset
754 }
kono
parents: 68
diff changeset
755
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
756 /* Attempt to replace a comparison with a prior arithmetic insn that can
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
757 compute the same flags value as the comparison itself. Return true if
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
758 successful, having made all rtl modifications necessary. */
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
759
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
760 static bool
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
761 try_eliminate_compare (struct comparison *cmp)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
762 {
145
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
763 rtx flags, in_a, in_b, cmp_a, cmp_b;
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
764
111
kono
parents: 68
diff changeset
765 if (try_merge_compare (cmp))
kono
parents: 68
diff changeset
766 return true;
kono
parents: 68
diff changeset
767
kono
parents: 68
diff changeset
768 /* We must have found an interesting "clobber" preceding the compare. */
kono
parents: 68
diff changeset
769 if (cmp->prev_clobber == NULL)
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
770 return false;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
771
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
772 /* Verify that IN_A is not clobbered in between CMP and PREV_CLOBBER.
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
773 Given that this target requires this pass, we can assume that most
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
774 insns do clobber the flags, and so the distance between the compare
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
775 and the clobber is likely to be small. */
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
776 /* ??? This is one point at which one could argue that DF_REF_CHAIN would
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
777 be useful, but it is thought to be too heavy-weight a solution here. */
111
kono
parents: 68
diff changeset
778 in_a = equivalent_reg_at_start (cmp->in_a, cmp->insn, cmp->prev_clobber);
kono
parents: 68
diff changeset
779 if (!in_a)
kono
parents: 68
diff changeset
780 return false;
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
781
111
kono
parents: 68
diff changeset
782 /* Likewise for IN_B if need be. */
kono
parents: 68
diff changeset
783 if (CONSTANT_P (cmp->in_b))
kono
parents: 68
diff changeset
784 in_b = cmp->in_b;
kono
parents: 68
diff changeset
785 else if (REG_P (cmp->in_b))
kono
parents: 68
diff changeset
786 {
kono
parents: 68
diff changeset
787 in_b = equivalent_reg_at_start (cmp->in_b, cmp->insn, cmp->prev_clobber);
kono
parents: 68
diff changeset
788 if (!in_b)
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
789 return false;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
790 }
111
kono
parents: 68
diff changeset
791 else if (GET_CODE (cmp->in_b) == UNSPEC)
kono
parents: 68
diff changeset
792 {
kono
parents: 68
diff changeset
793 const int len = XVECLEN (cmp->in_b, 0);
kono
parents: 68
diff changeset
794 rtvec v = rtvec_alloc (len);
kono
parents: 68
diff changeset
795 for (int i = 0; i < len; i++)
kono
parents: 68
diff changeset
796 {
kono
parents: 68
diff changeset
797 rtx r = equivalent_reg_at_start (XVECEXP (cmp->in_b, 0, i),
kono
parents: 68
diff changeset
798 cmp->insn, cmp->prev_clobber);
kono
parents: 68
diff changeset
799 if (!r)
kono
parents: 68
diff changeset
800 return false;
kono
parents: 68
diff changeset
801 RTVEC_ELT (v, i) = r;
kono
parents: 68
diff changeset
802 }
kono
parents: 68
diff changeset
803 in_b = gen_rtx_UNSPEC (GET_MODE (cmp->in_b), v, XINT (cmp->in_b, 1));
kono
parents: 68
diff changeset
804 }
kono
parents: 68
diff changeset
805 else
kono
parents: 68
diff changeset
806 gcc_unreachable ();
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
807
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
808 /* We've reached PREV_CLOBBER without finding a modification of IN_A.
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
809 Validate that PREV_CLOBBER itself does in fact refer to IN_A. Do
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
810 recall that we've already validated the shape of PREV_CLOBBER. */
111
kono
parents: 68
diff changeset
811 rtx_insn *insn = cmp->prev_clobber;
kono
parents: 68
diff changeset
812
kono
parents: 68
diff changeset
813 rtx x = XVECEXP (PATTERN (insn), 0, 0);
kono
parents: 68
diff changeset
814 if (rtx_equal_p (SET_DEST (x), in_a))
145
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
815 cmp_a = SET_SRC (x);
111
kono
parents: 68
diff changeset
816
kono
parents: 68
diff changeset
817 /* Also check operations with implicit extensions, e.g.:
kono
parents: 68
diff changeset
818 [(set (reg:DI)
kono
parents: 68
diff changeset
819 (zero_extend:DI (plus:SI (reg:SI) (reg:SI))))
kono
parents: 68
diff changeset
820 (set (reg:CCZ flags)
kono
parents: 68
diff changeset
821 (compare:CCZ (plus:SI (reg:SI) (reg:SI))
kono
parents: 68
diff changeset
822 (const_int 0)))] */
kono
parents: 68
diff changeset
823 else if (REG_P (SET_DEST (x))
kono
parents: 68
diff changeset
824 && REG_P (in_a)
kono
parents: 68
diff changeset
825 && REGNO (SET_DEST (x)) == REGNO (in_a)
kono
parents: 68
diff changeset
826 && (GET_CODE (SET_SRC (x)) == ZERO_EXTEND
kono
parents: 68
diff changeset
827 || GET_CODE (SET_SRC (x)) == SIGN_EXTEND)
kono
parents: 68
diff changeset
828 && GET_MODE (XEXP (SET_SRC (x), 0)) == GET_MODE (in_a))
145
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
829 cmp_a = XEXP (SET_SRC (x), 0);
111
kono
parents: 68
diff changeset
830
kono
parents: 68
diff changeset
831 /* Also check fully redundant comparisons, e.g.:
kono
parents: 68
diff changeset
832 [(set (reg:SI)
kono
parents: 68
diff changeset
833 (minus:SI (reg:SI) (reg:SI))))
kono
parents: 68
diff changeset
834 (set (reg:CC flags)
kono
parents: 68
diff changeset
835 (compare:CC (reg:SI) (reg:SI)))] */
kono
parents: 68
diff changeset
836 else if (REG_P (in_b)
kono
parents: 68
diff changeset
837 && GET_CODE (SET_SRC (x)) == MINUS
kono
parents: 68
diff changeset
838 && rtx_equal_p (XEXP (SET_SRC (x), 0), in_a)
kono
parents: 68
diff changeset
839 && rtx_equal_p (XEXP (SET_SRC (x), 1), in_b))
145
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
840 cmp_a = in_a;
111
kono
parents: 68
diff changeset
841
kono
parents: 68
diff changeset
842 else
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
843 return false;
111
kono
parents: 68
diff changeset
844
131
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
845 /* If the source uses addressing modes with side effects, we can't
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
846 do the merge because we'd end up with a PARALLEL that has two
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
847 instances of that side effect in it. */
145
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
848 if (side_effects_p (cmp_a))
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
849 return false;
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
850
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
851 if (in_a == in_b)
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
852 cmp_b = cmp_a;
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
853 else if (rtx_equal_p (SET_DEST (x), in_b))
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
854 cmp_b = SET_SRC (x);
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
855 else
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
856 cmp_b = in_b;
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
857 if (side_effects_p (cmp_b))
131
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
858 return false;
84e7813d76e9 gcc-8.2
mir3636
parents: 111
diff changeset
859
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
860 /* Determine if we ought to use a different CC_MODE here. */
145
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
861 flags = maybe_select_cc_mode (cmp, cmp_a, cmp_b);
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
862 if (flags == NULL)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
863 flags = gen_rtx_REG (cmp->orig_mode, targetm.flags_regnum);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
864
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
865 /* Generate a new comparison for installation in the setter. */
145
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
866 rtx y = cmp->not_in_a
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
867 ? gen_rtx_NOT (GET_MODE (cmp_a), copy_rtx (cmp_a))
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
868 : copy_rtx (cmp_a);
1830386684a0 gcc-9.2.0
anatofuz
parents: 131
diff changeset
869 y = gen_rtx_COMPARE (GET_MODE (flags), y, copy_rtx (cmp_b));
111
kono
parents: 68
diff changeset
870 y = gen_rtx_SET (flags, y);
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
871
111
kono
parents: 68
diff changeset
872 /* Canonicalize instruction to:
kono
parents: 68
diff changeset
873 [(set (reg:CCM) (compare:CCM (operation) (immediate)))
kono
parents: 68
diff changeset
874 (set (reg) (operation)] */
kono
parents: 68
diff changeset
875
kono
parents: 68
diff changeset
876 rtvec v = rtvec_alloc (2);
kono
parents: 68
diff changeset
877 RTVEC_ELT (v, 0) = y;
kono
parents: 68
diff changeset
878 RTVEC_ELT (v, 1) = x;
kono
parents: 68
diff changeset
879
kono
parents: 68
diff changeset
880 rtx pat = gen_rtx_PARALLEL (VOIDmode, v);
kono
parents: 68
diff changeset
881
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
882 /* Succeed if the new instruction is valid. Note that we may have started
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
883 a change group within maybe_select_cc_mode, therefore we must continue. */
111
kono
parents: 68
diff changeset
884 validate_change (insn, &PATTERN (insn), pat, true);
kono
parents: 68
diff changeset
885
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
886 if (!apply_change_group ())
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
887 return false;
111
kono
parents: 68
diff changeset
888
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
889 /* Success. Delete the compare insn... */
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
890 delete_insn (cmp->insn);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
891
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
892 /* ... and any notes that are now invalid due to multiple sets. */
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
893 x = find_regno_note (insn, REG_UNUSED, targetm.flags_regnum);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
894 if (x)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
895 remove_note (insn, x);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
896 x = find_reg_note (insn, REG_EQUAL, NULL);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
897 if (x)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
898 remove_note (insn, x);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
899 x = find_reg_note (insn, REG_EQUIV, NULL);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
900 if (x)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
901 remove_note (insn, x);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
902
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
903 return true;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
904 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
905
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
906 /* Main entry point to the pass. */
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
907
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
908 static unsigned int
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
909 execute_compare_elim_after_reload (void)
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
910 {
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
911 df_analyze ();
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
912
111
kono
parents: 68
diff changeset
913 gcc_checking_assert (!all_compares.exists ());
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
914
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
915 /* Locate all comparisons and their uses, and eliminate duplicates. */
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
916 find_comparisons ();
111
kono
parents: 68
diff changeset
917 if (all_compares.exists ())
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
918 {
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
919 struct comparison *cmp;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
920 size_t i;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
921
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
922 /* Eliminate comparisons that are redundant with flags computation. */
111
kono
parents: 68
diff changeset
923 FOR_EACH_VEC_ELT (all_compares, i, cmp)
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
924 {
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
925 try_eliminate_compare (cmp);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
926 XDELETE (cmp);
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
927 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
928
111
kono
parents: 68
diff changeset
929 all_compares.release ();
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
930 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
931
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
932 return 0;
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
933 }
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
934
111
kono
parents: 68
diff changeset
935 namespace {
kono
parents: 68
diff changeset
936
kono
parents: 68
diff changeset
937 const pass_data pass_data_compare_elim_after_reload =
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
938 {
111
kono
parents: 68
diff changeset
939 RTL_PASS, /* type */
kono
parents: 68
diff changeset
940 "cmpelim", /* name */
kono
parents: 68
diff changeset
941 OPTGROUP_NONE, /* optinfo_flags */
kono
parents: 68
diff changeset
942 TV_NONE, /* tv_id */
kono
parents: 68
diff changeset
943 0, /* properties_required */
kono
parents: 68
diff changeset
944 0, /* properties_provided */
kono
parents: 68
diff changeset
945 0, /* properties_destroyed */
kono
parents: 68
diff changeset
946 0, /* todo_flags_start */
kono
parents: 68
diff changeset
947 ( TODO_df_finish | TODO_df_verify ), /* todo_flags_finish */
kono
parents: 68
diff changeset
948 };
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
949
111
kono
parents: 68
diff changeset
950 class pass_compare_elim_after_reload : public rtl_opt_pass
68
561a7518be6b update gcc-4.6
Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
diff changeset
951 {
111
kono
parents: 68
diff changeset
952 public:
kono
parents: 68
diff changeset
953 pass_compare_elim_after_reload (gcc::context *ctxt)
kono
parents: 68
diff changeset
954 : rtl_opt_pass (pass_data_compare_elim_after_reload, ctxt)
kono
parents: 68
diff changeset
955 {}
kono
parents: 68
diff changeset
956
kono
parents: 68
diff changeset
957 /* opt_pass methods: */
kono
parents: 68
diff changeset
958 virtual bool gate (function *)
kono
parents: 68
diff changeset
959 {
kono
parents: 68
diff changeset
960 /* Setting this target hook value is how a backend indicates the need. */
kono
parents: 68
diff changeset
961 if (targetm.flags_regnum == INVALID_REGNUM)
kono
parents: 68
diff changeset
962 return false;
kono
parents: 68
diff changeset
963 return flag_compare_elim_after_reload;
kono
parents: 68
diff changeset
964 }
kono
parents: 68
diff changeset
965
kono
parents: 68
diff changeset
966 virtual unsigned int execute (function *)
kono
parents: 68
diff changeset
967 {
kono
parents: 68
diff changeset
968 return execute_compare_elim_after_reload ();
kono
parents: 68
diff changeset
969 }
kono
parents: 68
diff changeset
970
kono
parents: 68
diff changeset
971 }; // class pass_compare_elim_after_reload
kono
parents: 68
diff changeset
972
kono
parents: 68
diff changeset
973 } // anon namespace
kono
parents: 68
diff changeset
974
kono
parents: 68
diff changeset
975 rtl_opt_pass *
kono
parents: 68
diff changeset
976 make_pass_compare_elim_after_reload (gcc::context *ctxt)
kono
parents: 68
diff changeset
977 {
kono
parents: 68
diff changeset
978 return new pass_compare_elim_after_reload (ctxt);
kono
parents: 68
diff changeset
979 }