1 | /* Generate code from machine description to perform peephole optimizations. |
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2 | Copyright (C) 1987, 1989, 1992, 1997 Free Software Foundation, Inc. |
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3 | |
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4 | This file is part of GNU CC. |
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5 | |
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6 | GNU CC is free software; you can redistribute it and/or modify |
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7 | it under the terms of the GNU General Public License as published by |
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8 | the Free Software Foundation; either version 2, or (at your option) |
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9 | any later version. |
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10 | |
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11 | GNU CC is distributed in the hope that it will be useful, |
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12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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14 | GNU General Public License for more details. |
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15 | |
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16 | You should have received a copy of the GNU General Public License |
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17 | along with GNU CC; see the file COPYING. If not, write to |
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18 | the Free Software Foundation, 59 Temple Place - Suite 330, |
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19 | Boston, MA 02111-1307, USA. */ |
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20 | |
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21 | |
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22 | #include <stdio.h> |
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23 | #include "hconfig.h" |
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24 | #include "rtl.h" |
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25 | #include "obstack.h" |
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26 | |
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27 | static struct obstack obstack; |
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28 | struct obstack *rtl_obstack = &obstack; |
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29 | |
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30 | #define obstack_chunk_alloc xmalloc |
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31 | #define obstack_chunk_free free |
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32 | |
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33 | extern void free (); |
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34 | extern rtx read_rtx (); |
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35 | |
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36 | /* While tree-walking an instruction pattern, we keep a chain |
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37 | of these `struct link's to record how to get down to the |
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38 | current position. In each one, POS is the operand number, |
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39 | and if the operand is a vector VEC is the element number. |
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40 | VEC is -1 if the operand is not a vector. */ |
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41 | |
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42 | struct link |
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43 | { |
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44 | struct link *next; |
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45 | int pos; |
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46 | int vecelt; |
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47 | }; |
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48 | |
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49 | char *xmalloc (); |
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50 | static void match_rtx (); |
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51 | static void fatal (); |
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52 | void fancy_abort (); |
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53 | |
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54 | static int max_opno; |
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55 | |
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56 | /* Number of operands used in current peephole definition. */ |
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57 | |
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58 | static int n_operands; |
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59 | |
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60 | /* Peephole optimizations get insn codes just like insn patterns. |
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61 | Count them so we know the code of the define_peephole we are handling. */ |
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62 | |
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63 | static int insn_code_number = 0; |
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64 | |
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65 | static void print_path (); |
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66 | static void print_code (); |
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67 | |
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68 | static void |
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69 | gen_peephole (peep) |
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70 | rtx peep; |
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71 | { |
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72 | int ninsns = XVECLEN (peep, 0); |
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73 | int i; |
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74 | |
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75 | n_operands = 0; |
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76 | |
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77 | printf (" insn = ins1;\n"); |
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78 | #if 0 |
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79 | printf (" want_jump = 0;\n"); |
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80 | #endif |
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81 | |
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82 | for (i = 0; i < ninsns; i++) |
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83 | { |
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84 | if (i > 0) |
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85 | { |
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86 | printf (" do { insn = NEXT_INSN (insn);\n"); |
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87 | printf (" if (insn == 0) goto L%d; }\n", |
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88 | insn_code_number); |
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89 | printf (" while (GET_CODE (insn) == NOTE\n"); |
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90 | printf ("\t || (GET_CODE (insn) == INSN\n"); |
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91 | printf ("\t && (GET_CODE (PATTERN (insn)) == USE\n"); |
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92 | printf ("\t\t || GET_CODE (PATTERN (insn)) == CLOBBER)));\n"); |
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93 | |
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94 | printf (" if (GET_CODE (insn) == CODE_LABEL\n\ |
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95 | || GET_CODE (insn) == BARRIER)\n goto L%d;\n", |
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96 | insn_code_number); |
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97 | } |
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98 | |
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99 | #if 0 |
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100 | printf (" if (GET_CODE (insn) == JUMP_INSN)\n"); |
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101 | printf (" want_jump = JUMP_LABEL (insn);\n"); |
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102 | #endif |
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103 | |
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104 | printf (" pat = PATTERN (insn);\n"); |
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105 | |
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106 | /* Walk the insn's pattern, remembering at all times the path |
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107 | down to the walking point. */ |
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108 | |
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109 | match_rtx (XVECEXP (peep, 0, i), NULL_PTR, insn_code_number); |
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110 | } |
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111 | |
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112 | /* We get this far if the pattern matches. |
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113 | Now test the extra condition. */ |
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114 | |
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115 | if (XSTR (peep, 1) && XSTR (peep, 1)[0]) |
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116 | printf (" if (! (%s)) goto L%d;\n", |
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117 | XSTR (peep, 1), insn_code_number); |
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118 | |
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119 | /* If that matches, construct new pattern and put it in the first insn. |
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120 | This new pattern will never be matched. |
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121 | It exists only so that insn-extract can get the operands back. |
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122 | So use a simple regular form: a PARALLEL containing a vector |
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123 | of all the operands. */ |
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124 | |
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125 | printf (" PATTERN (ins1) = gen_rtx (PARALLEL, VOIDmode, gen_rtvec_v (%d, operands));\n", n_operands); |
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126 | |
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127 | #if 0 |
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128 | printf (" if (want_jump && GET_CODE (ins1) != JUMP_INSN)\n"); |
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129 | printf (" {\n"); |
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130 | printf (" rtx insn2 = emit_jump_insn_before (PATTERN (ins1), ins1);\n"); |
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131 | printf (" delete_insn (ins1);\n"); |
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132 | printf (" ins1 = ins2;\n"); |
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133 | printf (" }\n"); |
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134 | #endif |
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135 | |
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136 | /* Record this define_peephole's insn code in the insn, |
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137 | as if it had been recognized to match this. */ |
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138 | printf (" INSN_CODE (ins1) = %d;\n", |
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139 | insn_code_number); |
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140 | |
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141 | /* Delete the remaining insns. */ |
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142 | if (ninsns > 1) |
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143 | printf (" delete_for_peephole (NEXT_INSN (ins1), insn);\n"); |
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144 | |
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145 | /* See reload1.c for insertion of NOTE which guarantees that this |
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146 | cannot be zero. */ |
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147 | printf (" return NEXT_INSN (insn);\n"); |
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148 | |
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149 | printf (" L%d:\n\n", insn_code_number); |
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150 | } |
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151 | |
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152 | static void |
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153 | match_rtx (x, path, fail_label) |
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154 | rtx x; |
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155 | struct link *path; |
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156 | int fail_label; |
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157 | { |
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158 | register RTX_CODE code; |
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159 | register int i; |
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160 | register int len; |
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161 | register char *fmt; |
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162 | struct link link; |
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163 | |
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164 | if (x == 0) |
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165 | return; |
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166 | |
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167 | |
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168 | code = GET_CODE (x); |
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169 | |
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170 | switch (code) |
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171 | { |
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172 | case MATCH_OPERAND: |
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173 | if (XINT (x, 0) > max_opno) |
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174 | max_opno = XINT (x, 0); |
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175 | if (XINT (x, 0) >= n_operands) |
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176 | n_operands = 1 + XINT (x, 0); |
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177 | |
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178 | printf (" x = "); |
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179 | print_path (path); |
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180 | printf (";\n"); |
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181 | |
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182 | printf (" operands[%d] = x;\n", XINT (x, 0)); |
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183 | if (XSTR (x, 1) && XSTR (x, 1)[0]) |
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184 | printf (" if (! %s (x, %smode)) goto L%d;\n", |
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185 | XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label); |
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186 | return; |
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187 | |
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188 | case MATCH_DUP: |
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189 | case MATCH_PAR_DUP: |
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190 | printf (" x = "); |
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191 | print_path (path); |
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192 | printf (";\n"); |
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193 | |
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194 | printf (" if (!rtx_equal_p (operands[%d], x)) goto L%d;\n", |
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195 | XINT (x, 0), fail_label); |
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196 | return; |
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197 | |
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198 | case MATCH_OP_DUP: |
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199 | printf (" x = "); |
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200 | print_path (path); |
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201 | printf (";\n"); |
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202 | |
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203 | printf (" if (GET_CODE (operands[%d]) != GET_CODE (x)\n", XINT (x, 0)); |
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204 | printf (" || GET_MODE (operands[%d]) != GET_MODE (x)) goto L%d;\n", |
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205 | XINT (x, 0), fail_label); |
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206 | printf (" operands[%d] = x;\n", XINT (x, 0)); |
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207 | link.next = path; |
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208 | link.vecelt = -1; |
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209 | for (i = 0; i < XVECLEN (x, 1); i++) |
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210 | { |
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211 | link.pos = i; |
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212 | match_rtx (XVECEXP (x, 1, i), &link, fail_label); |
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213 | } |
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214 | return; |
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215 | |
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216 | case MATCH_OPERATOR: |
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217 | if (XINT (x, 0) > max_opno) |
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218 | max_opno = XINT (x, 0); |
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219 | if (XINT (x, 0) >= n_operands) |
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220 | n_operands = 1 + XINT (x, 0); |
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221 | |
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222 | printf (" x = "); |
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223 | print_path (path); |
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224 | printf (";\n"); |
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225 | |
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226 | printf (" operands[%d] = x;\n", XINT (x, 0)); |
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227 | if (XSTR (x, 1) && XSTR (x, 1)[0]) |
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228 | printf (" if (! %s (x, %smode)) goto L%d;\n", |
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229 | XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label); |
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230 | link.next = path; |
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231 | link.vecelt = -1; |
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232 | for (i = 0; i < XVECLEN (x, 2); i++) |
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233 | { |
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234 | link.pos = i; |
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235 | match_rtx (XVECEXP (x, 2, i), &link, fail_label); |
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236 | } |
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237 | return; |
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238 | |
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239 | case MATCH_PARALLEL: |
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240 | if (XINT (x, 0) > max_opno) |
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241 | max_opno = XINT (x, 0); |
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242 | if (XINT (x, 0) >= n_operands) |
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243 | n_operands = 1 + XINT (x, 0); |
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244 | |
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245 | printf (" x = "); |
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246 | print_path (path); |
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247 | printf (";\n"); |
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248 | |
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249 | printf (" if (GET_CODE (x) != PARALLEL) goto L%d;\n", fail_label); |
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250 | printf (" operands[%d] = x;\n", XINT (x, 0)); |
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251 | if (XSTR (x, 1) && XSTR (x, 1)[0]) |
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252 | printf (" if (! %s (x, %smode)) goto L%d;\n", |
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253 | XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label); |
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254 | link.next = path; |
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255 | link.pos = 0; |
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256 | for (i = 0; i < XVECLEN (x, 2); i++) |
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257 | { |
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258 | link.vecelt = i; |
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259 | match_rtx (XVECEXP (x, 2, i), &link, fail_label); |
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260 | } |
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261 | return; |
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262 | |
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263 | case ADDRESS: |
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264 | match_rtx (XEXP (x, 0), path, fail_label); |
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265 | return; |
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266 | |
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267 | default: |
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268 | break; |
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269 | } |
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270 | |
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271 | printf (" x = "); |
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272 | print_path (path); |
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273 | printf (";\n"); |
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274 | |
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275 | printf (" if (GET_CODE (x) != "); |
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276 | print_code (code); |
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277 | printf (") goto L%d;\n", fail_label); |
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278 | |
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279 | if (GET_MODE (x) != VOIDmode) |
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280 | { |
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281 | printf (" if (GET_MODE (x) != %smode) goto L%d;\n", |
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282 | GET_MODE_NAME (GET_MODE (x)), fail_label); |
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283 | } |
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284 | |
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285 | link.next = path; |
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286 | link.vecelt = -1; |
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287 | fmt = GET_RTX_FORMAT (code); |
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288 | len = GET_RTX_LENGTH (code); |
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289 | for (i = 0; i < len; i++) |
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290 | { |
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291 | link.pos = i; |
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292 | if (fmt[i] == 'e' || fmt[i] == 'u') |
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293 | match_rtx (XEXP (x, i), &link, fail_label); |
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294 | else if (fmt[i] == 'E') |
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295 | { |
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296 | int j; |
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297 | printf (" if (XVECLEN (x, %d) != %d) goto L%d;\n", |
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298 | i, XVECLEN (x, i), fail_label); |
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299 | for (j = 0; j < XVECLEN (x, i); j++) |
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300 | { |
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301 | link.vecelt = j; |
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302 | match_rtx (XVECEXP (x, i, j), &link, fail_label); |
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303 | } |
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304 | } |
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305 | else if (fmt[i] == 'i') |
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306 | { |
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307 | /* Make sure that at run time `x' is the RTX we want to test. */ |
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308 | if (i != 0) |
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309 | { |
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310 | printf (" x = "); |
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311 | print_path (path); |
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312 | printf (";\n"); |
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313 | } |
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314 | |
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315 | printf (" if (XINT (x, %d) != %d) goto L%d;\n", |
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316 | i, XINT (x, i), fail_label); |
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317 | } |
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318 | else if (fmt[i] == 'w') |
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319 | { |
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320 | /* Make sure that at run time `x' is the RTX we want to test. */ |
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321 | if (i != 0) |
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322 | { |
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323 | printf (" x = "); |
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324 | print_path (path); |
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325 | printf (";\n"); |
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326 | } |
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327 | |
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328 | #if HOST_BITS_PER_WIDE_INT == HOST_BITS_PER_INT |
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329 | printf (" if (XWINT (x, %d) != %d) goto L%d;\n", |
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330 | i, XWINT (x, i), fail_label); |
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331 | #else |
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332 | printf (" if (XWINT (x, %d) != %ld) goto L%d;\n", |
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333 | i, XWINT (x, i), fail_label); |
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334 | #endif |
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335 | } |
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336 | else if (fmt[i] == 's') |
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337 | { |
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338 | /* Make sure that at run time `x' is the RTX we want to test. */ |
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339 | if (i != 0) |
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340 | { |
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341 | printf (" x = "); |
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342 | print_path (path); |
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343 | printf (";\n"); |
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344 | } |
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345 | |
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346 | printf (" if (strcmp (XSTR (x, %d), \"%s\")) goto L%d;\n", |
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347 | i, XSTR (x, i), fail_label); |
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348 | } |
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349 | } |
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350 | } |
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351 | |
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352 | /* Given a PATH, representing a path down the instruction's |
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353 | pattern from the root to a certain point, output code to |
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354 | evaluate to the rtx at that point. */ |
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355 | |
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356 | static void |
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357 | print_path (path) |
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358 | struct link *path; |
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359 | { |
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360 | if (path == 0) |
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361 | printf ("pat"); |
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362 | else if (path->vecelt >= 0) |
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363 | { |
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364 | printf ("XVECEXP ("); |
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365 | print_path (path->next); |
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366 | printf (", %d, %d)", path->pos, path->vecelt); |
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367 | } |
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368 | else |
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369 | { |
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370 | printf ("XEXP ("); |
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371 | print_path (path->next); |
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372 | printf (", %d)", path->pos); |
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373 | } |
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374 | } |
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375 | |
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376 | static void |
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377 | print_code (code) |
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378 | RTX_CODE code; |
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379 | { |
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380 | register char *p1; |
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381 | for (p1 = GET_RTX_NAME (code); *p1; p1++) |
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382 | { |
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383 | if (*p1 >= 'a' && *p1 <= 'z') |
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384 | putchar (*p1 + 'A' - 'a'); |
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385 | else |
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386 | putchar (*p1); |
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387 | } |
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388 | } |
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389 | |
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390 | char * |
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391 | xmalloc (size) |
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392 | unsigned size; |
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393 | { |
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394 | register char *val = (char *) malloc (size); |
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395 | |
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396 | if (val == 0) |
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397 | fatal ("virtual memory exhausted"); |
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398 | return val; |
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399 | } |
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400 | |
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401 | char * |
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402 | xrealloc (ptr, size) |
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403 | char *ptr; |
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404 | unsigned size; |
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405 | { |
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406 | char *result = (char *) realloc (ptr, size); |
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407 | if (!result) |
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408 | fatal ("virtual memory exhausted"); |
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409 | return result; |
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410 | } |
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411 | |
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412 | static void |
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413 | fatal (s, a1, a2) |
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414 | char *s; |
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415 | { |
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416 | fprintf (stderr, "genpeep: "); |
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417 | fprintf (stderr, s, a1, a2); |
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418 | fprintf (stderr, "\n"); |
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419 | exit (FATAL_EXIT_CODE); |
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420 | } |
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421 | |
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422 | /* More 'friendly' abort that prints the line and file. |
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423 | config.h can #define abort fancy_abort if you like that sort of thing. */ |
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424 | |
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425 | void |
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426 | fancy_abort () |
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427 | { |
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428 | fatal ("Internal gcc abort."); |
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429 | } |
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430 | |
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431 | int |
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432 | main (argc, argv) |
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433 | int argc; |
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434 | char **argv; |
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435 | { |
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436 | rtx desc; |
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437 | FILE *infile; |
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438 | register int c; |
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439 | |
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440 | max_opno = -1; |
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441 | |
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442 | obstack_init (rtl_obstack); |
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443 | |
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444 | if (argc <= 1) |
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445 | fatal ("No input file name."); |
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446 | |
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447 | infile = fopen (argv[1], "r"); |
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448 | if (infile == 0) |
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449 | { |
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450 | perror (argv[1]); |
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451 | exit (FATAL_EXIT_CODE); |
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452 | } |
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453 | |
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454 | init_rtl (); |
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455 | |
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456 | printf ("/* Generated automatically by the program `genpeep'\n\ |
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457 | from the machine description file `md'. */\n\n"); |
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458 | |
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459 | printf ("#include \"config.h\"\n"); |
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460 | printf ("#include <stdio.h>\n"); |
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461 | printf ("#include \"rtl.h\"\n"); |
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462 | printf ("#include \"regs.h\"\n"); |
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463 | printf ("#include \"output.h\"\n"); |
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464 | printf ("#include \"real.h\"\n\n"); |
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465 | |
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466 | printf ("extern rtx peep_operand[];\n\n"); |
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467 | printf ("#define operands peep_operand\n\n"); |
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468 | |
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469 | printf ("rtx\npeephole (ins1)\n rtx ins1;\n{\n"); |
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470 | printf (" rtx insn, x, pat;\n"); |
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471 | printf (" int i;\n\n"); |
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472 | |
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473 | /* Early out: no peepholes for insns followed by barriers. */ |
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474 | printf (" if (NEXT_INSN (ins1)\n"); |
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475 | printf (" && GET_CODE (NEXT_INSN (ins1)) == BARRIER)\n"); |
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476 | printf (" return 0;\n\n"); |
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477 | |
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478 | /* Read the machine description. */ |
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479 | |
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480 | while (1) |
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481 | { |
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482 | c = read_skip_spaces (infile); |
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483 | if (c == EOF) |
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484 | break; |
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485 | ungetc (c, infile); |
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486 | |
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487 | desc = read_rtx (infile); |
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488 | if (GET_CODE (desc) == DEFINE_PEEPHOLE) |
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489 | { |
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490 | gen_peephole (desc); |
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491 | insn_code_number++; |
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492 | } |
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493 | if (GET_CODE (desc) == DEFINE_INSN |
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494 | || GET_CODE (desc) == DEFINE_EXPAND |
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495 | || GET_CODE (desc) == DEFINE_SPLIT) |
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496 | { |
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497 | insn_code_number++; |
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498 | } |
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499 | } |
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500 | |
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501 | printf (" return 0;\n}\n\n"); |
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502 | |
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503 | if (max_opno == -1) |
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504 | max_opno = 1; |
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505 | |
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506 | printf ("rtx peep_operand[%d];\n", max_opno + 1); |
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507 | |
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508 | fflush (stdout); |
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509 | exit (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE); |
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510 | /* NOTREACHED */ |
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511 | return 0; |
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512 | } |
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