1 /* Copyright (C) 2007-2021 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 #define BID_128RES 25 #include "bid_internal.h" 26 27 #define DECIMAL_EXPONENT_BIAS_128 6176 28 #define MAX_DECIMAL_EXPONENT_128 12287 29 30 31 32 BID128_FUNCTION_ARG128_ARGTYPE2 (bid128_scalb, x, int, n) 33 34 UINT128 CX, CX2, CX8, res; 35 SINT64 exp64; 36 UINT64 sign_x; 37 int exponent_x, rmode; 38 39 // unpack arguments, check for NaN or Infinity 40 if (!unpack_BID128_value (&sign_x, &exponent_x, &CX, x)) { 41 // x is Inf. or NaN or 0 42 #ifdef SET_STATUS_FLAGS 43 if ((x.w[1] & SNAN_MASK64) == SNAN_MASK64) // y is sNaN 44 __set_status_flags (pfpsf, INVALID_EXCEPTION); 45 #endif 46 res.w[1] = CX.w[1] & QUIET_MASK64; 47 res.w[0] = CX.w[0]; 48 if (!CX.w[1]) { 49 exp64 = (SINT64) exponent_x + (SINT64) n; 50 if(exp64<0) exp64=0; 51 if(exp64>MAX_DECIMAL_EXPONENT_128) exp64=MAX_DECIMAL_EXPONENT_128; 52 exponent_x = exp64; 53 get_BID128_very_fast (&res, sign_x, exponent_x, CX); 54 } 55 BID_RETURN (res); 56 } 57 58 exp64 = (SINT64) exponent_x + (SINT64) n; 59 exponent_x = exp64; 60 61 if ((UINT32) exponent_x <= MAX_DECIMAL_EXPONENT_128) { 62 get_BID128_very_fast (&res, sign_x, exponent_x, CX); 63 BID_RETURN (res); 64 } 65 // check for overflow 66 if (exp64 > MAX_DECIMAL_EXPONENT_128) { 67 if (CX.w[1] < 0x314dc6448d93ull) { 68 // try to normalize coefficient 69 do { 70 CX8.w[1] = (CX.w[1] << 3) | (CX.w[0] >> 61); 71 CX8.w[0] = CX.w[0] << 3; 72 CX2.w[1] = (CX.w[1] << 1) | (CX.w[0] >> 63); 73 CX2.w[0] = CX.w[0] << 1; 74 __add_128_128 (CX, CX2, CX8); 75 76 exponent_x--; 77 exp64--; 78 } 79 while (CX.w[1] < 0x314dc6448d93ull 80 && exp64 > MAX_DECIMAL_EXPONENT_128); 81 82 } 83 if (exp64 <= MAX_DECIMAL_EXPONENT_128) { 84 get_BID128_very_fast (&res, sign_x, exponent_x, CX); 85 BID_RETURN (res); 86 } else 87 exponent_x = 0x7fffffff; // overflow 88 } 89 // exponent < 0 90 // the BID pack routine will round the coefficient 91 rmode = rnd_mode; 92 get_BID128 (&res, sign_x, exponent_x, CX, (unsigned int *) &rmode, 93 pfpsf); 94 BID_RETURN (res); 95 96 } 97