1 /* Copyright (C) 2007, 2009 Free Software Foundation, Inc. 2 3 This file is part of GCC. 4 5 GCC is free software; you can redistribute it and/or modify it under 6 the terms of the GNU General Public License as published by the Free 7 Software Foundation; either version 3, or (at your option) any later 8 version. 9 10 GCC is distributed in the hope that it will be useful, but WITHOUT ANY 11 WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 for more details. 14 15 Under Section 7 of GPL version 3, you are granted additional 16 permissions described in the GCC Runtime Library Exception, version 17 3.1, as published by the Free Software Foundation. 18 19 You should have received a copy of the GNU General Public License and 20 a copy of the GCC Runtime Library Exception along with this program; 21 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 22 <http://www.gnu.org/licenses/>. */ 23 24 #include "bid_internal.h" 25 26 /* 27 * Takes a BID32 as input and converts it to a BID64 and returns it. 28 */ 29 TYPE0_FUNCTION_ARGTYPE1_NORND (UINT64, bid32_to_bid64, UINT32, x) 30 31 UINT64 res; 32 UINT32 sign_x; 33 int exponent_x; 34 UINT32 coefficient_x; 35 36 if (!unpack_BID32 (&sign_x, &exponent_x, &coefficient_x, x)) { 37 // Inf, NaN, 0 38 if (((x) & 0x78000000) == 0x78000000) { 39 if (((x) & 0x7e000000) == 0x7e000000) { // sNaN 40 #ifdef SET_STATUS_FLAGS 41 __set_status_flags (pfpsf, INVALID_EXCEPTION); 42 #endif 43 } 44 res = (coefficient_x & 0x000fffff); 45 res *= 1000000000; 46 res |= ((((UINT64) coefficient_x) << 32) & 0xfc00000000000000ull); 47 48 BID_RETURN (res); 49 } 50 } 51 52 res = 53 very_fast_get_BID64_small_mantissa (((UINT64) sign_x) << 32, 54 exponent_x + 55 DECIMAL_EXPONENT_BIAS - 56 DECIMAL_EXPONENT_BIAS_32, 57 (UINT64) coefficient_x); 58 BID_RETURN (res); 59 } // convert_bid32_to_bid64 60 61 62 /* 63 * Takes a BID64 as input and converts it to a BID32 and returns it. 64 */ 65 #if DECIMAL_CALL_BY_REFERENCE 66 67 void 68 bid64_to_bid32 (UINT32 * pres, 69 UINT64 * 70 px _RND_MODE_PARAM _EXC_FLAGS_PARAM _EXC_MASKS_PARAM 71 _EXC_INFO_PARAM) { 72 UINT64 x; 73 #else 74 75 UINT32 76 bid64_to_bid32 (UINT64 x _RND_MODE_PARAM _EXC_FLAGS_PARAM 77 _EXC_MASKS_PARAM _EXC_INFO_PARAM) { 78 #endif 79 UINT128 Q; 80 UINT64 sign_x, coefficient_x, remainder_h, carry, Stemp; 81 UINT32 res; 82 int_float tempx; 83 int exponent_x, bin_expon_cx, extra_digits, rmode = 0, amount; 84 unsigned status = 0; 85 86 #if DECIMAL_CALL_BY_REFERENCE 87 #if !DECIMAL_GLOBAL_ROUNDING 88 _IDEC_round rnd_mode = *prnd_mode; 89 #endif 90 x = *px; 91 #endif 92 93 // unpack arguments, check for NaN or Infinity, 0 94 if (!unpack_BID64 (&sign_x, &exponent_x, &coefficient_x, x)) { 95 if (((x) & 0x7800000000000000ull) == 0x7800000000000000ull) { 96 res = (coefficient_x & 0x0003ffffffffffffull); 97 res /= 1000000000ull; 98 res |= ((coefficient_x >> 32) & 0xfc000000); 99 #ifdef SET_STATUS_FLAGS 100 if ((x & SNAN_MASK64) == SNAN_MASK64) // sNaN 101 __set_status_flags (pfpsf, INVALID_EXCEPTION); 102 #endif 103 BID_RETURN (res); 104 } 105 exponent_x = 106 exponent_x - DECIMAL_EXPONENT_BIAS + DECIMAL_EXPONENT_BIAS_32; 107 if (exponent_x < 0) 108 exponent_x = 0; 109 if (exponent_x > DECIMAL_MAX_EXPON_32) 110 exponent_x = DECIMAL_MAX_EXPON_32; 111 res = (sign_x >> 32) | (exponent_x << 23); 112 BID_RETURN (res); 113 } 114 115 exponent_x = 116 exponent_x - DECIMAL_EXPONENT_BIAS + DECIMAL_EXPONENT_BIAS_32; 117 118 // check number of digits 119 if (coefficient_x >= 10000000) { 120 tempx.d = (float) coefficient_x; 121 bin_expon_cx = ((tempx.i >> 23) & 0xff) - 0x7f; 122 extra_digits = estimate_decimal_digits[bin_expon_cx] - 7; 123 // add test for range 124 if (coefficient_x >= power10_index_binexp[bin_expon_cx]) 125 extra_digits++; 126 127 #ifndef IEEE_ROUND_NEAREST_TIES_AWAY 128 #ifndef IEEE_ROUND_NEAREST 129 rmode = rnd_mode; 130 if (sign_x && (unsigned) (rmode - 1) < 2) 131 rmode = 3 - rmode; 132 #else 133 rmode = 0; 134 #endif 135 #else 136 rmode = 0; 137 #endif 138 139 exponent_x += extra_digits; 140 if ((exponent_x < 0) && (exponent_x + MAX_FORMAT_DIGITS_32 >= 0)) { 141 status = UNDERFLOW_EXCEPTION; 142 if (exponent_x == -1) 143 if (coefficient_x + round_const_table[rmode][extra_digits] >= 144 power10_table_128[extra_digits + 7].w[0]) 145 status = 0; 146 extra_digits -= exponent_x; 147 exponent_x = 0; 148 } 149 coefficient_x += round_const_table[rmode][extra_digits]; 150 __mul_64x64_to_128 (Q, coefficient_x, 151 reciprocals10_64[extra_digits]); 152 153 // now get P/10^extra_digits: shift Q_high right by M[extra_digits]-128 154 amount = short_recip_scale[extra_digits]; 155 156 coefficient_x = Q.w[1] >> amount; 157 158 #ifndef IEEE_ROUND_NEAREST_TIES_AWAY 159 #ifndef IEEE_ROUND_NEAREST 160 if (rmode == 0) //ROUNDING_TO_NEAREST 161 #endif 162 if (coefficient_x & 1) { 163 // check whether fractional part of initial_P/10^extra_digits 164 // is exactly .5 165 166 // get remainder 167 remainder_h = Q.w[1] << (64 - amount); 168 169 if (!remainder_h && (Q.w[0] < reciprocals10_64[extra_digits])) 170 coefficient_x--; 171 } 172 #endif 173 174 #ifdef SET_STATUS_FLAGS 175 176 { 177 status |= INEXACT_EXCEPTION; 178 // get remainder 179 remainder_h = Q.w[1] << (64 - amount); 180 181 switch (rmode) { 182 case ROUNDING_TO_NEAREST: 183 case ROUNDING_TIES_AWAY: 184 // test whether fractional part is 0 185 if (remainder_h == 0x8000000000000000ull 186 && (Q.w[0] < reciprocals10_64[extra_digits])) 187 status = EXACT_STATUS; 188 break; 189 case ROUNDING_DOWN: 190 case ROUNDING_TO_ZERO: 191 if (!remainder_h && (Q.w[0] < reciprocals10_64[extra_digits])) 192 status = EXACT_STATUS; 193 break; 194 default: 195 // round up 196 __add_carry_out (Stemp, carry, Q.w[0], 197 reciprocals10_64[extra_digits]); 198 if ((remainder_h >> (64 - amount)) + carry >= 199 (((UINT64) 1) << amount)) 200 status = EXACT_STATUS; 201 } 202 203 if (status != EXACT_STATUS) 204 __set_status_flags (pfpsf, status); 205 } 206 207 #endif 208 209 } 210 211 res = 212 get_BID32 ((UINT32) (sign_x >> 32), 213 exponent_x, coefficient_x, rnd_mode, pfpsf); 214 BID_RETURN (res); 215 216 } 217