0
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1 /* Utility routines for data type conversion for GCC.
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2 Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1997, 1998,
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3 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
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4 Free Software Foundation, Inc.
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5
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6 This file is part of GCC.
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7
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8 GCC is free software; you can redistribute it and/or modify it under
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9 the terms of the GNU General Public License as published by the Free
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10 Software Foundation; either version 3, or (at your option) any later
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11 version.
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12
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13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
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15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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16 for more details.
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17
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18 You should have received a copy of the GNU General Public License
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19 along with GCC; see the file COPYING3. If not see
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20 <http://www.gnu.org/licenses/>. */
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21
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22
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23 /* These routines are somewhat language-independent utility function
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24 intended to be called by the language-specific convert () functions. */
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25
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26 #include "config.h"
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27 #include "system.h"
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28 #include "coretypes.h"
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29 #include "tm.h"
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30 #include "tree.h"
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31 #include "flags.h"
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32 #include "convert.h"
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33 #include "toplev.h"
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34 #include "langhooks.h"
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35 #include "real.h"
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36 #include "fixed-value.h"
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37
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38 /* Convert EXPR to some pointer or reference type TYPE.
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39 EXPR must be pointer, reference, integer, enumeral, or literal zero;
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40 in other cases error is called. */
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41
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42 tree
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43 convert_to_pointer (tree type, tree expr)
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44 {
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45 if (TREE_TYPE (expr) == type)
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46 return expr;
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47
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48 /* Propagate overflow to the NULL pointer. */
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49 if (integer_zerop (expr))
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50 return force_fit_type_double (type, 0, 0, 0, TREE_OVERFLOW (expr));
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51
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52 switch (TREE_CODE (TREE_TYPE (expr)))
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53 {
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54 case POINTER_TYPE:
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55 case REFERENCE_TYPE:
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56 return fold_build1 (NOP_EXPR, type, expr);
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57
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58 case INTEGER_TYPE:
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59 case ENUMERAL_TYPE:
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60 case BOOLEAN_TYPE:
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61 if (TYPE_PRECISION (TREE_TYPE (expr)) != POINTER_SIZE)
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62 expr = fold_build1 (NOP_EXPR,
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63 lang_hooks.types.type_for_size (POINTER_SIZE, 0),
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64 expr);
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65 return fold_build1 (CONVERT_EXPR, type, expr);
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66
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67
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68 default:
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69 error ("cannot convert to a pointer type");
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70 return convert_to_pointer (type, integer_zero_node);
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71 }
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72 }
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73
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74 /* Avoid any floating point extensions from EXP. */
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75 tree
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76 strip_float_extensions (tree exp)
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77 {
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78 tree sub, expt, subt;
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79
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80 /* For floating point constant look up the narrowest type that can hold
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81 it properly and handle it like (type)(narrowest_type)constant.
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82 This way we can optimize for instance a=a*2.0 where "a" is float
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83 but 2.0 is double constant. */
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84 if (TREE_CODE (exp) == REAL_CST && !DECIMAL_FLOAT_TYPE_P (TREE_TYPE (exp)))
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85 {
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86 REAL_VALUE_TYPE orig;
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87 tree type = NULL;
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88
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89 orig = TREE_REAL_CST (exp);
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90 if (TYPE_PRECISION (TREE_TYPE (exp)) > TYPE_PRECISION (float_type_node)
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91 && exact_real_truncate (TYPE_MODE (float_type_node), &orig))
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92 type = float_type_node;
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93 else if (TYPE_PRECISION (TREE_TYPE (exp))
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94 > TYPE_PRECISION (double_type_node)
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95 && exact_real_truncate (TYPE_MODE (double_type_node), &orig))
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96 type = double_type_node;
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97 if (type)
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98 return build_real (type, real_value_truncate (TYPE_MODE (type), orig));
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99 }
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100
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101 if (!CONVERT_EXPR_P (exp))
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102 return exp;
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103
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104 sub = TREE_OPERAND (exp, 0);
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105 subt = TREE_TYPE (sub);
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106 expt = TREE_TYPE (exp);
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107
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108 if (!FLOAT_TYPE_P (subt))
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109 return exp;
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110
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111 if (DECIMAL_FLOAT_TYPE_P (expt) != DECIMAL_FLOAT_TYPE_P (subt))
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112 return exp;
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113
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114 if (TYPE_PRECISION (subt) > TYPE_PRECISION (expt))
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115 return exp;
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116
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117 return strip_float_extensions (sub);
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118 }
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119
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120
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121 /* Convert EXPR to some floating-point type TYPE.
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122
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123 EXPR must be float, fixed-point, integer, or enumeral;
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124 in other cases error is called. */
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125
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126 tree
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127 convert_to_real (tree type, tree expr)
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128 {
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129 enum built_in_function fcode = builtin_mathfn_code (expr);
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130 tree itype = TREE_TYPE (expr);
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131
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132 /* Disable until we figure out how to decide whether the functions are
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133 present in runtime. */
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134 /* Convert (float)sqrt((double)x) where x is float into sqrtf(x) */
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135 if (optimize
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136 && (TYPE_MODE (type) == TYPE_MODE (double_type_node)
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137 || TYPE_MODE (type) == TYPE_MODE (float_type_node)))
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138 {
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139 switch (fcode)
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140 {
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141 #define CASE_MATHFN(FN) case BUILT_IN_##FN: case BUILT_IN_##FN##L:
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142 CASE_MATHFN (COSH)
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143 CASE_MATHFN (EXP)
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144 CASE_MATHFN (EXP10)
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145 CASE_MATHFN (EXP2)
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146 CASE_MATHFN (EXPM1)
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147 CASE_MATHFN (GAMMA)
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148 CASE_MATHFN (J0)
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149 CASE_MATHFN (J1)
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150 CASE_MATHFN (LGAMMA)
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151 CASE_MATHFN (POW10)
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152 CASE_MATHFN (SINH)
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153 CASE_MATHFN (TGAMMA)
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154 CASE_MATHFN (Y0)
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155 CASE_MATHFN (Y1)
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156 /* The above functions may set errno differently with float
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157 input or output so this transformation is not safe with
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158 -fmath-errno. */
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159 if (flag_errno_math)
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160 break;
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161 CASE_MATHFN (ACOS)
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162 CASE_MATHFN (ACOSH)
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163 CASE_MATHFN (ASIN)
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164 CASE_MATHFN (ASINH)
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165 CASE_MATHFN (ATAN)
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166 CASE_MATHFN (ATANH)
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167 CASE_MATHFN (CBRT)
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168 CASE_MATHFN (COS)
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169 CASE_MATHFN (ERF)
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170 CASE_MATHFN (ERFC)
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171 CASE_MATHFN (FABS)
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172 CASE_MATHFN (LOG)
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173 CASE_MATHFN (LOG10)
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174 CASE_MATHFN (LOG2)
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175 CASE_MATHFN (LOG1P)
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176 CASE_MATHFN (LOGB)
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177 CASE_MATHFN (SIN)
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178 CASE_MATHFN (SQRT)
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179 CASE_MATHFN (TAN)
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180 CASE_MATHFN (TANH)
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181 #undef CASE_MATHFN
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182 {
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183 tree arg0 = strip_float_extensions (CALL_EXPR_ARG (expr, 0));
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184 tree newtype = type;
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185
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186 /* We have (outertype)sqrt((innertype)x). Choose the wider mode from
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187 the both as the safe type for operation. */
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188 if (TYPE_PRECISION (TREE_TYPE (arg0)) > TYPE_PRECISION (type))
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189 newtype = TREE_TYPE (arg0);
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190
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191 /* Be careful about integer to fp conversions.
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192 These may overflow still. */
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193 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
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194 && TYPE_PRECISION (newtype) < TYPE_PRECISION (itype)
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195 && (TYPE_MODE (newtype) == TYPE_MODE (double_type_node)
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196 || TYPE_MODE (newtype) == TYPE_MODE (float_type_node)))
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197 {
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198 tree fn = mathfn_built_in (newtype, fcode);
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199
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200 if (fn)
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201 {
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202 tree arg = fold (convert_to_real (newtype, arg0));
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203 expr = build_call_expr (fn, 1, arg);
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204 if (newtype == type)
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205 return expr;
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206 }
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207 }
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208 }
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209 default:
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210 break;
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211 }
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212 }
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213 if (optimize
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214 && (((fcode == BUILT_IN_FLOORL
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215 || fcode == BUILT_IN_CEILL
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216 || fcode == BUILT_IN_ROUNDL
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217 || fcode == BUILT_IN_RINTL
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218 || fcode == BUILT_IN_TRUNCL
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219 || fcode == BUILT_IN_NEARBYINTL)
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220 && (TYPE_MODE (type) == TYPE_MODE (double_type_node)
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221 || TYPE_MODE (type) == TYPE_MODE (float_type_node)))
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222 || ((fcode == BUILT_IN_FLOOR
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223 || fcode == BUILT_IN_CEIL
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224 || fcode == BUILT_IN_ROUND
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225 || fcode == BUILT_IN_RINT
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226 || fcode == BUILT_IN_TRUNC
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227 || fcode == BUILT_IN_NEARBYINT)
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228 && (TYPE_MODE (type) == TYPE_MODE (float_type_node)))))
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229 {
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230 tree fn = mathfn_built_in (type, fcode);
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231
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232 if (fn)
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233 {
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234 tree arg = strip_float_extensions (CALL_EXPR_ARG (expr, 0));
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235
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236 /* Make sure (type)arg0 is an extension, otherwise we could end up
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237 changing (float)floor(double d) into floorf((float)d), which is
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238 incorrect because (float)d uses round-to-nearest and can round
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239 up to the next integer. */
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240 if (TYPE_PRECISION (type) >= TYPE_PRECISION (TREE_TYPE (arg)))
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241 return build_call_expr (fn, 1, fold (convert_to_real (type, arg)));
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242 }
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243 }
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244
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245 /* Propagate the cast into the operation. */
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246 if (itype != type && FLOAT_TYPE_P (type))
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247 switch (TREE_CODE (expr))
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248 {
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249 /* Convert (float)-x into -(float)x. This is safe for
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250 round-to-nearest rounding mode. */
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251 case ABS_EXPR:
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252 case NEGATE_EXPR:
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253 if (!flag_rounding_math
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254 && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (expr)))
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255 return build1 (TREE_CODE (expr), type,
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256 fold (convert_to_real (type,
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257 TREE_OPERAND (expr, 0))));
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258 break;
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259 /* Convert (outertype)((innertype0)a+(innertype1)b)
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260 into ((newtype)a+(newtype)b) where newtype
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261 is the widest mode from all of these. */
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262 case PLUS_EXPR:
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263 case MINUS_EXPR:
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264 case MULT_EXPR:
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265 case RDIV_EXPR:
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266 {
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267 tree arg0 = strip_float_extensions (TREE_OPERAND (expr, 0));
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268 tree arg1 = strip_float_extensions (TREE_OPERAND (expr, 1));
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269
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270 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
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271 && FLOAT_TYPE_P (TREE_TYPE (arg1))
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272 && DECIMAL_FLOAT_TYPE_P (itype) == DECIMAL_FLOAT_TYPE_P (type))
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273 {
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274 tree newtype = type;
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275
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276 if (TYPE_MODE (TREE_TYPE (arg0)) == SDmode
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277 || TYPE_MODE (TREE_TYPE (arg1)) == SDmode
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278 || TYPE_MODE (type) == SDmode)
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279 newtype = dfloat32_type_node;
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280 if (TYPE_MODE (TREE_TYPE (arg0)) == DDmode
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281 || TYPE_MODE (TREE_TYPE (arg1)) == DDmode
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282 || TYPE_MODE (type) == DDmode)
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283 newtype = dfloat64_type_node;
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284 if (TYPE_MODE (TREE_TYPE (arg0)) == TDmode
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285 || TYPE_MODE (TREE_TYPE (arg1)) == TDmode
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286 || TYPE_MODE (type) == TDmode)
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287 newtype = dfloat128_type_node;
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288 if (newtype == dfloat32_type_node
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289 || newtype == dfloat64_type_node
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290 || newtype == dfloat128_type_node)
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291 {
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292 expr = build2 (TREE_CODE (expr), newtype,
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293 fold (convert_to_real (newtype, arg0)),
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294 fold (convert_to_real (newtype, arg1)));
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295 if (newtype == type)
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296 return expr;
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297 break;
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298 }
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299
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300 if (TYPE_PRECISION (TREE_TYPE (arg0)) > TYPE_PRECISION (newtype))
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301 newtype = TREE_TYPE (arg0);
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302 if (TYPE_PRECISION (TREE_TYPE (arg1)) > TYPE_PRECISION (newtype))
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303 newtype = TREE_TYPE (arg1);
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304 /* Sometimes this transformation is safe (cannot
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305 change results through affecting double rounding
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306 cases) and sometimes it is not. If NEWTYPE is
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307 wider than TYPE, e.g. (float)((long double)double
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308 + (long double)double) converted to
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309 (float)(double + double), the transformation is
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310 unsafe regardless of the details of the types
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311 involved; double rounding can arise if the result
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312 of NEWTYPE arithmetic is a NEWTYPE value half way
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313 between two representable TYPE values but the
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314 exact value is sufficiently different (in the
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315 right direction) for this difference to be
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316 visible in ITYPE arithmetic. If NEWTYPE is the
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317 same as TYPE, however, the transformation may be
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318 safe depending on the types involved: it is safe
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319 if the ITYPE has strictly more than twice as many
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320 mantissa bits as TYPE, can represent infinities
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321 and NaNs if the TYPE can, and has sufficient
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322 exponent range for the product or ratio of two
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323 values representable in the TYPE to be within the
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324 range of normal values of ITYPE. */
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325 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (itype)
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326 && (flag_unsafe_math_optimizations
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327 || (TYPE_PRECISION (newtype) == TYPE_PRECISION (type)
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328 && real_can_shorten_arithmetic (TYPE_MODE (itype),
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329 TYPE_MODE (type)))))
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330 {
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331 expr = build2 (TREE_CODE (expr), newtype,
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332 fold (convert_to_real (newtype, arg0)),
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333 fold (convert_to_real (newtype, arg1)));
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334 if (newtype == type)
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335 return expr;
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336 }
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337 }
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338 }
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339 break;
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340 default:
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341 break;
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342 }
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343
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344 switch (TREE_CODE (TREE_TYPE (expr)))
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345 {
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346 case REAL_TYPE:
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347 /* Ignore the conversion if we don't need to store intermediate
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348 results and neither type is a decimal float. */
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349 return build1 ((flag_float_store
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350 || DECIMAL_FLOAT_TYPE_P (type)
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351 || DECIMAL_FLOAT_TYPE_P (itype))
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352 ? CONVERT_EXPR : NOP_EXPR, type, expr);
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353
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354 case INTEGER_TYPE:
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355 case ENUMERAL_TYPE:
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356 case BOOLEAN_TYPE:
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357 return build1 (FLOAT_EXPR, type, expr);
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358
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359 case FIXED_POINT_TYPE:
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360 return build1 (FIXED_CONVERT_EXPR, type, expr);
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361
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362 case COMPLEX_TYPE:
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363 return convert (type,
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364 fold_build1 (REALPART_EXPR,
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365 TREE_TYPE (TREE_TYPE (expr)), expr));
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366
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367 case POINTER_TYPE:
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368 case REFERENCE_TYPE:
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369 error ("pointer value used where a floating point value was expected");
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370 return convert_to_real (type, integer_zero_node);
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371
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372 default:
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373 error ("aggregate value used where a float was expected");
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374 return convert_to_real (type, integer_zero_node);
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375 }
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376 }
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377
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378 /* Convert EXPR to some integer (or enum) type TYPE.
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379
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380 EXPR must be pointer, integer, discrete (enum, char, or bool), float,
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381 fixed-point or vector; in other cases error is called.
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382
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383 The result of this is always supposed to be a newly created tree node
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384 not in use in any existing structure. */
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385
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386 tree
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387 convert_to_integer (tree type, tree expr)
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388 {
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389 enum tree_code ex_form = TREE_CODE (expr);
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390 tree intype = TREE_TYPE (expr);
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391 unsigned int inprec = TYPE_PRECISION (intype);
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392 unsigned int outprec = TYPE_PRECISION (type);
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393
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394 /* An INTEGER_TYPE cannot be incomplete, but an ENUMERAL_TYPE can
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395 be. Consider `enum E = { a, b = (enum E) 3 };'. */
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396 if (!COMPLETE_TYPE_P (type))
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397 {
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398 error ("conversion to incomplete type");
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399 return error_mark_node;
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400 }
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401
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402 /* Convert e.g. (long)round(d) -> lround(d). */
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403 /* If we're converting to char, we may encounter differing behavior
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404 between converting from double->char vs double->long->char.
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405 We're in "undefined" territory but we prefer to be conservative,
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406 so only proceed in "unsafe" math mode. */
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407 if (optimize
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408 && (flag_unsafe_math_optimizations
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409 || (long_integer_type_node
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410 && outprec >= TYPE_PRECISION (long_integer_type_node))))
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411 {
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412 tree s_expr = strip_float_extensions (expr);
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413 tree s_intype = TREE_TYPE (s_expr);
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414 const enum built_in_function fcode = builtin_mathfn_code (s_expr);
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415 tree fn = 0;
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416
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417 switch (fcode)
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418 {
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419 CASE_FLT_FN (BUILT_IN_CEIL):
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420 /* Only convert in ISO C99 mode. */
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421 if (!TARGET_C99_FUNCTIONS)
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422 break;
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423 if (outprec < TYPE_PRECISION (long_integer_type_node)
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424 || (outprec == TYPE_PRECISION (long_integer_type_node)
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425 && !TYPE_UNSIGNED (type)))
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426 fn = mathfn_built_in (s_intype, BUILT_IN_LCEIL);
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427 else if (outprec == TYPE_PRECISION (long_long_integer_type_node)
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428 && !TYPE_UNSIGNED (type))
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429 fn = mathfn_built_in (s_intype, BUILT_IN_LLCEIL);
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430 break;
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431
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432 CASE_FLT_FN (BUILT_IN_FLOOR):
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433 /* Only convert in ISO C99 mode. */
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434 if (!TARGET_C99_FUNCTIONS)
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435 break;
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436 if (outprec < TYPE_PRECISION (long_integer_type_node)
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437 || (outprec == TYPE_PRECISION (long_integer_type_node)
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438 && !TYPE_UNSIGNED (type)))
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439 fn = mathfn_built_in (s_intype, BUILT_IN_LFLOOR);
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440 else if (outprec == TYPE_PRECISION (long_long_integer_type_node)
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441 && !TYPE_UNSIGNED (type))
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442 fn = mathfn_built_in (s_intype, BUILT_IN_LLFLOOR);
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443 break;
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444
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445 CASE_FLT_FN (BUILT_IN_ROUND):
|
|
446 if (outprec < TYPE_PRECISION (long_integer_type_node)
|
|
447 || (outprec == TYPE_PRECISION (long_integer_type_node)
|
|
448 && !TYPE_UNSIGNED (type)))
|
|
449 fn = mathfn_built_in (s_intype, BUILT_IN_LROUND);
|
|
450 else if (outprec == TYPE_PRECISION (long_long_integer_type_node)
|
|
451 && !TYPE_UNSIGNED (type))
|
|
452 fn = mathfn_built_in (s_intype, BUILT_IN_LLROUND);
|
|
453 break;
|
|
454
|
|
455 CASE_FLT_FN (BUILT_IN_NEARBYINT):
|
|
456 /* Only convert nearbyint* if we can ignore math exceptions. */
|
|
457 if (flag_trapping_math)
|
|
458 break;
|
|
459 /* ... Fall through ... */
|
|
460 CASE_FLT_FN (BUILT_IN_RINT):
|
|
461 if (outprec < TYPE_PRECISION (long_integer_type_node)
|
|
462 || (outprec == TYPE_PRECISION (long_integer_type_node)
|
|
463 && !TYPE_UNSIGNED (type)))
|
|
464 fn = mathfn_built_in (s_intype, BUILT_IN_LRINT);
|
|
465 else if (outprec == TYPE_PRECISION (long_long_integer_type_node)
|
|
466 && !TYPE_UNSIGNED (type))
|
|
467 fn = mathfn_built_in (s_intype, BUILT_IN_LLRINT);
|
|
468 break;
|
|
469
|
|
470 CASE_FLT_FN (BUILT_IN_TRUNC):
|
|
471 return convert_to_integer (type, CALL_EXPR_ARG (s_expr, 0));
|
|
472
|
|
473 default:
|
|
474 break;
|
|
475 }
|
|
476
|
|
477 if (fn)
|
|
478 {
|
|
479 tree newexpr = build_call_expr (fn, 1, CALL_EXPR_ARG (s_expr, 0));
|
|
480 return convert_to_integer (type, newexpr);
|
|
481 }
|
|
482 }
|
|
483
|
|
484 switch (TREE_CODE (intype))
|
|
485 {
|
|
486 case POINTER_TYPE:
|
|
487 case REFERENCE_TYPE:
|
|
488 if (integer_zerop (expr))
|
|
489 return build_int_cst (type, 0);
|
|
490
|
|
491 /* Convert to an unsigned integer of the correct width first,
|
|
492 and from there widen/truncate to the required type. */
|
|
493 expr = fold_build1 (CONVERT_EXPR,
|
|
494 lang_hooks.types.type_for_size (POINTER_SIZE, 0),
|
|
495 expr);
|
|
496 return fold_convert (type, expr);
|
|
497
|
|
498 case INTEGER_TYPE:
|
|
499 case ENUMERAL_TYPE:
|
|
500 case BOOLEAN_TYPE:
|
|
501 case OFFSET_TYPE:
|
|
502 /* If this is a logical operation, which just returns 0 or 1, we can
|
|
503 change the type of the expression. */
|
|
504
|
|
505 if (TREE_CODE_CLASS (ex_form) == tcc_comparison)
|
|
506 {
|
|
507 expr = copy_node (expr);
|
|
508 TREE_TYPE (expr) = type;
|
|
509 return expr;
|
|
510 }
|
|
511
|
|
512 /* If we are widening the type, put in an explicit conversion.
|
|
513 Similarly if we are not changing the width. After this, we know
|
|
514 we are truncating EXPR. */
|
|
515
|
|
516 else if (outprec >= inprec)
|
|
517 {
|
|
518 enum tree_code code;
|
|
519 tree tem;
|
|
520
|
|
521 /* If the precision of the EXPR's type is K bits and the
|
|
522 destination mode has more bits, and the sign is changing,
|
|
523 it is not safe to use a NOP_EXPR. For example, suppose
|
|
524 that EXPR's type is a 3-bit unsigned integer type, the
|
|
525 TYPE is a 3-bit signed integer type, and the machine mode
|
|
526 for the types is 8-bit QImode. In that case, the
|
|
527 conversion necessitates an explicit sign-extension. In
|
|
528 the signed-to-unsigned case the high-order bits have to
|
|
529 be cleared. */
|
|
530 if (TYPE_UNSIGNED (type) != TYPE_UNSIGNED (TREE_TYPE (expr))
|
|
531 && (TYPE_PRECISION (TREE_TYPE (expr))
|
|
532 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (expr)))))
|
|
533 code = CONVERT_EXPR;
|
|
534 else
|
|
535 code = NOP_EXPR;
|
|
536
|
|
537 tem = fold_unary (code, type, expr);
|
|
538 if (tem)
|
|
539 return tem;
|
|
540
|
|
541 tem = build1 (code, type, expr);
|
|
542 TREE_NO_WARNING (tem) = 1;
|
|
543 return tem;
|
|
544 }
|
|
545
|
|
546 /* If TYPE is an enumeral type or a type with a precision less
|
|
547 than the number of bits in its mode, do the conversion to the
|
|
548 type corresponding to its mode, then do a nop conversion
|
|
549 to TYPE. */
|
|
550 else if (TREE_CODE (type) == ENUMERAL_TYPE
|
|
551 || outprec != GET_MODE_BITSIZE (TYPE_MODE (type)))
|
|
552 return build1 (NOP_EXPR, type,
|
|
553 convert (lang_hooks.types.type_for_mode
|
|
554 (TYPE_MODE (type), TYPE_UNSIGNED (type)),
|
|
555 expr));
|
|
556
|
|
557 /* Here detect when we can distribute the truncation down past some
|
|
558 arithmetic. For example, if adding two longs and converting to an
|
|
559 int, we can equally well convert both to ints and then add.
|
|
560 For the operations handled here, such truncation distribution
|
|
561 is always safe.
|
|
562 It is desirable in these cases:
|
|
563 1) when truncating down to full-word from a larger size
|
|
564 2) when truncating takes no work.
|
|
565 3) when at least one operand of the arithmetic has been extended
|
|
566 (as by C's default conversions). In this case we need two conversions
|
|
567 if we do the arithmetic as already requested, so we might as well
|
|
568 truncate both and then combine. Perhaps that way we need only one.
|
|
569
|
|
570 Note that in general we cannot do the arithmetic in a type
|
|
571 shorter than the desired result of conversion, even if the operands
|
|
572 are both extended from a shorter type, because they might overflow
|
|
573 if combined in that type. The exceptions to this--the times when
|
|
574 two narrow values can be combined in their narrow type even to
|
|
575 make a wider result--are handled by "shorten" in build_binary_op. */
|
|
576
|
|
577 switch (ex_form)
|
|
578 {
|
|
579 case RSHIFT_EXPR:
|
|
580 /* We can pass truncation down through right shifting
|
|
581 when the shift count is a nonpositive constant. */
|
|
582 if (TREE_CODE (TREE_OPERAND (expr, 1)) == INTEGER_CST
|
|
583 && tree_int_cst_sgn (TREE_OPERAND (expr, 1)) <= 0)
|
|
584 goto trunc1;
|
|
585 break;
|
|
586
|
|
587 case LSHIFT_EXPR:
|
|
588 /* We can pass truncation down through left shifting
|
|
589 when the shift count is a nonnegative constant and
|
|
590 the target type is unsigned. */
|
|
591 if (TREE_CODE (TREE_OPERAND (expr, 1)) == INTEGER_CST
|
|
592 && tree_int_cst_sgn (TREE_OPERAND (expr, 1)) >= 0
|
|
593 && TYPE_UNSIGNED (type)
|
|
594 && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST)
|
|
595 {
|
|
596 /* If shift count is less than the width of the truncated type,
|
|
597 really shift. */
|
|
598 if (tree_int_cst_lt (TREE_OPERAND (expr, 1), TYPE_SIZE (type)))
|
|
599 /* In this case, shifting is like multiplication. */
|
|
600 goto trunc1;
|
|
601 else
|
|
602 {
|
|
603 /* If it is >= that width, result is zero.
|
|
604 Handling this with trunc1 would give the wrong result:
|
|
605 (int) ((long long) a << 32) is well defined (as 0)
|
|
606 but (int) a << 32 is undefined and would get a
|
|
607 warning. */
|
|
608
|
|
609 tree t = build_int_cst (type, 0);
|
|
610
|
|
611 /* If the original expression had side-effects, we must
|
|
612 preserve it. */
|
|
613 if (TREE_SIDE_EFFECTS (expr))
|
|
614 return build2 (COMPOUND_EXPR, type, expr, t);
|
|
615 else
|
|
616 return t;
|
|
617 }
|
|
618 }
|
|
619 break;
|
|
620
|
|
621 case MAX_EXPR:
|
|
622 case MIN_EXPR:
|
|
623 case MULT_EXPR:
|
|
624 {
|
|
625 tree arg0 = get_unwidened (TREE_OPERAND (expr, 0), type);
|
|
626 tree arg1 = get_unwidened (TREE_OPERAND (expr, 1), type);
|
|
627
|
|
628 /* Don't distribute unless the output precision is at least as big
|
|
629 as the actual inputs. Otherwise, the comparison of the
|
|
630 truncated values will be wrong. */
|
|
631 if (outprec >= TYPE_PRECISION (TREE_TYPE (arg0))
|
|
632 && outprec >= TYPE_PRECISION (TREE_TYPE (arg1))
|
|
633 /* If signedness of arg0 and arg1 don't match,
|
|
634 we can't necessarily find a type to compare them in. */
|
|
635 && (TYPE_UNSIGNED (TREE_TYPE (arg0))
|
|
636 == TYPE_UNSIGNED (TREE_TYPE (arg1))))
|
|
637 goto trunc1;
|
|
638 break;
|
|
639 }
|
|
640
|
|
641 case PLUS_EXPR:
|
|
642 case MINUS_EXPR:
|
|
643 case BIT_AND_EXPR:
|
|
644 case BIT_IOR_EXPR:
|
|
645 case BIT_XOR_EXPR:
|
|
646 trunc1:
|
|
647 {
|
|
648 tree arg0 = get_unwidened (TREE_OPERAND (expr, 0), type);
|
|
649 tree arg1 = get_unwidened (TREE_OPERAND (expr, 1), type);
|
|
650
|
|
651 if (outprec >= BITS_PER_WORD
|
|
652 || TRULY_NOOP_TRUNCATION (outprec, inprec)
|
|
653 || inprec > TYPE_PRECISION (TREE_TYPE (arg0))
|
|
654 || inprec > TYPE_PRECISION (TREE_TYPE (arg1)))
|
|
655 {
|
|
656 /* Do the arithmetic in type TYPEX,
|
|
657 then convert result to TYPE. */
|
|
658 tree typex = type;
|
|
659
|
|
660 /* Can't do arithmetic in enumeral types
|
|
661 so use an integer type that will hold the values. */
|
|
662 if (TREE_CODE (typex) == ENUMERAL_TYPE)
|
|
663 typex = lang_hooks.types.type_for_size
|
|
664 (TYPE_PRECISION (typex), TYPE_UNSIGNED (typex));
|
|
665
|
|
666 /* But now perhaps TYPEX is as wide as INPREC.
|
|
667 In that case, do nothing special here.
|
|
668 (Otherwise would recurse infinitely in convert. */
|
|
669 if (TYPE_PRECISION (typex) != inprec)
|
|
670 {
|
|
671 /* Don't do unsigned arithmetic where signed was wanted,
|
|
672 or vice versa.
|
|
673 Exception: if both of the original operands were
|
|
674 unsigned then we can safely do the work as unsigned.
|
|
675 Exception: shift operations take their type solely
|
|
676 from the first argument.
|
|
677 Exception: the LSHIFT_EXPR case above requires that
|
|
678 we perform this operation unsigned lest we produce
|
|
679 signed-overflow undefinedness.
|
|
680 And we may need to do it as unsigned
|
|
681 if we truncate to the original size. */
|
|
682 if (TYPE_UNSIGNED (TREE_TYPE (expr))
|
|
683 || (TYPE_UNSIGNED (TREE_TYPE (arg0))
|
|
684 && (TYPE_UNSIGNED (TREE_TYPE (arg1))
|
|
685 || ex_form == LSHIFT_EXPR
|
|
686 || ex_form == RSHIFT_EXPR
|
|
687 || ex_form == LROTATE_EXPR
|
|
688 || ex_form == RROTATE_EXPR))
|
|
689 || ex_form == LSHIFT_EXPR
|
|
690 /* If we have !flag_wrapv, and either ARG0 or
|
|
691 ARG1 is of a signed type, we have to do
|
|
692 PLUS_EXPR or MINUS_EXPR in an unsigned
|
|
693 type. Otherwise, we would introduce
|
|
694 signed-overflow undefinedness. */
|
|
695 || ((!TYPE_OVERFLOW_WRAPS (TREE_TYPE (arg0))
|
|
696 || !TYPE_OVERFLOW_WRAPS (TREE_TYPE (arg1)))
|
|
697 && (ex_form == PLUS_EXPR
|
|
698 || ex_form == MINUS_EXPR)))
|
|
699 typex = unsigned_type_for (typex);
|
|
700 else
|
|
701 typex = signed_type_for (typex);
|
|
702 return convert (type,
|
|
703 fold_build2 (ex_form, typex,
|
|
704 convert (typex, arg0),
|
|
705 convert (typex, arg1)));
|
|
706 }
|
|
707 }
|
|
708 }
|
|
709 break;
|
|
710
|
|
711 case NEGATE_EXPR:
|
|
712 case BIT_NOT_EXPR:
|
|
713 /* This is not correct for ABS_EXPR,
|
|
714 since we must test the sign before truncation. */
|
|
715 {
|
|
716 tree typex;
|
|
717
|
|
718 /* Don't do unsigned arithmetic where signed was wanted,
|
|
719 or vice versa. */
|
|
720 if (TYPE_UNSIGNED (TREE_TYPE (expr)))
|
|
721 typex = unsigned_type_for (type);
|
|
722 else
|
|
723 typex = signed_type_for (type);
|
|
724 return convert (type,
|
|
725 fold_build1 (ex_form, typex,
|
|
726 convert (typex,
|
|
727 TREE_OPERAND (expr, 0))));
|
|
728 }
|
|
729
|
|
730 case NOP_EXPR:
|
|
731 /* Don't introduce a
|
|
732 "can't convert between vector values of different size" error. */
|
|
733 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == VECTOR_TYPE
|
|
734 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_OPERAND (expr, 0))))
|
|
735 != GET_MODE_SIZE (TYPE_MODE (type))))
|
|
736 break;
|
|
737 /* If truncating after truncating, might as well do all at once.
|
|
738 If truncating after extending, we may get rid of wasted work. */
|
|
739 return convert (type, get_unwidened (TREE_OPERAND (expr, 0), type));
|
|
740
|
|
741 case COND_EXPR:
|
|
742 /* It is sometimes worthwhile to push the narrowing down through
|
|
743 the conditional and never loses. */
|
|
744 return fold_build3 (COND_EXPR, type, TREE_OPERAND (expr, 0),
|
|
745 convert (type, TREE_OPERAND (expr, 1)),
|
|
746 convert (type, TREE_OPERAND (expr, 2)));
|
|
747
|
|
748 default:
|
|
749 break;
|
|
750 }
|
|
751
|
|
752 return build1 (CONVERT_EXPR, type, expr);
|
|
753
|
|
754 case REAL_TYPE:
|
|
755 return build1 (FIX_TRUNC_EXPR, type, expr);
|
|
756
|
|
757 case FIXED_POINT_TYPE:
|
|
758 return build1 (FIXED_CONVERT_EXPR, type, expr);
|
|
759
|
|
760 case COMPLEX_TYPE:
|
|
761 return convert (type,
|
|
762 fold_build1 (REALPART_EXPR,
|
|
763 TREE_TYPE (TREE_TYPE (expr)), expr));
|
|
764
|
|
765 case VECTOR_TYPE:
|
|
766 if (!tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (TREE_TYPE (expr))))
|
|
767 {
|
|
768 error ("can't convert between vector values of different size");
|
|
769 return error_mark_node;
|
|
770 }
|
|
771 return build1 (VIEW_CONVERT_EXPR, type, expr);
|
|
772
|
|
773 default:
|
|
774 error ("aggregate value used where an integer was expected");
|
|
775 return convert (type, integer_zero_node);
|
|
776 }
|
|
777 }
|
|
778
|
|
779 /* Convert EXPR to the complex type TYPE in the usual ways. */
|
|
780
|
|
781 tree
|
|
782 convert_to_complex (tree type, tree expr)
|
|
783 {
|
|
784 tree subtype = TREE_TYPE (type);
|
|
785
|
|
786 switch (TREE_CODE (TREE_TYPE (expr)))
|
|
787 {
|
|
788 case REAL_TYPE:
|
|
789 case FIXED_POINT_TYPE:
|
|
790 case INTEGER_TYPE:
|
|
791 case ENUMERAL_TYPE:
|
|
792 case BOOLEAN_TYPE:
|
|
793 return build2 (COMPLEX_EXPR, type, convert (subtype, expr),
|
|
794 convert (subtype, integer_zero_node));
|
|
795
|
|
796 case COMPLEX_TYPE:
|
|
797 {
|
|
798 tree elt_type = TREE_TYPE (TREE_TYPE (expr));
|
|
799
|
|
800 if (TYPE_MAIN_VARIANT (elt_type) == TYPE_MAIN_VARIANT (subtype))
|
|
801 return expr;
|
|
802 else if (TREE_CODE (expr) == COMPLEX_EXPR)
|
|
803 return fold_build2 (COMPLEX_EXPR, type,
|
|
804 convert (subtype, TREE_OPERAND (expr, 0)),
|
|
805 convert (subtype, TREE_OPERAND (expr, 1)));
|
|
806 else
|
|
807 {
|
|
808 expr = save_expr (expr);
|
|
809 return
|
|
810 fold_build2 (COMPLEX_EXPR, type,
|
|
811 convert (subtype,
|
|
812 fold_build1 (REALPART_EXPR,
|
|
813 TREE_TYPE (TREE_TYPE (expr)),
|
|
814 expr)),
|
|
815 convert (subtype,
|
|
816 fold_build1 (IMAGPART_EXPR,
|
|
817 TREE_TYPE (TREE_TYPE (expr)),
|
|
818 expr)));
|
|
819 }
|
|
820 }
|
|
821
|
|
822 case POINTER_TYPE:
|
|
823 case REFERENCE_TYPE:
|
|
824 error ("pointer value used where a complex was expected");
|
|
825 return convert_to_complex (type, integer_zero_node);
|
|
826
|
|
827 default:
|
|
828 error ("aggregate value used where a complex was expected");
|
|
829 return convert_to_complex (type, integer_zero_node);
|
|
830 }
|
|
831 }
|
|
832
|
|
833 /* Convert EXPR to the vector type TYPE in the usual ways. */
|
|
834
|
|
835 tree
|
|
836 convert_to_vector (tree type, tree expr)
|
|
837 {
|
|
838 switch (TREE_CODE (TREE_TYPE (expr)))
|
|
839 {
|
|
840 case INTEGER_TYPE:
|
|
841 case VECTOR_TYPE:
|
|
842 if (!tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (TREE_TYPE (expr))))
|
|
843 {
|
|
844 error ("can't convert between vector values of different size");
|
|
845 return error_mark_node;
|
|
846 }
|
|
847 return build1 (VIEW_CONVERT_EXPR, type, expr);
|
|
848
|
|
849 default:
|
|
850 error ("can't convert value to a vector");
|
|
851 return error_mark_node;
|
|
852 }
|
|
853 }
|
|
854
|
|
855 /* Convert EXPR to some fixed-point type TYPE.
|
|
856
|
|
857 EXPR must be fixed-point, float, integer, or enumeral;
|
|
858 in other cases error is called. */
|
|
859
|
|
860 tree
|
|
861 convert_to_fixed (tree type, tree expr)
|
|
862 {
|
|
863 if (integer_zerop (expr))
|
|
864 {
|
|
865 tree fixed_zero_node = build_fixed (type, FCONST0 (TYPE_MODE (type)));
|
|
866 return fixed_zero_node;
|
|
867 }
|
|
868 else if (integer_onep (expr) && ALL_SCALAR_ACCUM_MODE_P (TYPE_MODE (type)))
|
|
869 {
|
|
870 tree fixed_one_node = build_fixed (type, FCONST1 (TYPE_MODE (type)));
|
|
871 return fixed_one_node;
|
|
872 }
|
|
873
|
|
874 switch (TREE_CODE (TREE_TYPE (expr)))
|
|
875 {
|
|
876 case FIXED_POINT_TYPE:
|
|
877 case INTEGER_TYPE:
|
|
878 case ENUMERAL_TYPE:
|
|
879 case BOOLEAN_TYPE:
|
|
880 case REAL_TYPE:
|
|
881 return build1 (FIXED_CONVERT_EXPR, type, expr);
|
|
882
|
|
883 case COMPLEX_TYPE:
|
|
884 return convert (type,
|
|
885 fold_build1 (REALPART_EXPR,
|
|
886 TREE_TYPE (TREE_TYPE (expr)), expr));
|
|
887
|
|
888 default:
|
|
889 error ("aggregate value used where a fixed-point was expected");
|
|
890 return error_mark_node;
|
|
891 }
|
|
892 }
|