1/* Copyright (C) 2007-2015 Free Software Foundation, Inc. 2 3This file is part of GCC. 4 5GCC is free software; you can redistribute it and/or modify it under 6the terms of the GNU General Public License as published by the Free 7Software Foundation; either version 3, or (at your option) any later 8version. 9 10GCC is distributed in the hope that it will be useful, but WITHOUT ANY 11WARRANTY; without even the implied warranty of MERCHANTABILITY or 12FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13for more details. 14 15Under Section 7 of GPL version 3, you are granted additional 16permissions described in the GCC Runtime Library Exception, version 173.1, as published by the Free Software Foundation. 18 19You should have received a copy of the GNU General Public License and 20a copy of the GCC Runtime Library Exception along with this program; 21see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 22<http://www.gnu.org/licenses/>. */ 23 24#include "bid_internal.h" 25 26#define MAX_FORMAT_DIGITS 16 27#define DECIMAL_EXPONENT_BIAS 398 28#define MAX_DECIMAL_EXPONENT 767 29 30#if DECIMAL_CALL_BY_REFERENCE 31 32void 33bid64_scalb (UINT64 * pres, UINT64 * px, 34 int *pn _RND_MODE_PARAM _EXC_FLAGS_PARAM _EXC_MASKS_PARAM 35 _EXC_INFO_PARAM) { 36 UINT64 x; 37 int n; 38#else 39 40UINT64 41bid64_scalb (UINT64 x, 42 int n _RND_MODE_PARAM _EXC_FLAGS_PARAM _EXC_MASKS_PARAM 43 _EXC_INFO_PARAM) { 44#endif 45 UINT64 sign_x, coefficient_x, res; 46 SINT64 exp64; 47 int exponent_x, rmode; 48 49#if DECIMAL_CALL_BY_REFERENCE 50#if !DECIMAL_GLOBAL_ROUNDING 51 _IDEC_round rnd_mode = *prnd_mode; 52#endif 53 x = *px; 54 n = *pn; 55#endif 56 57 // unpack arguments, check for NaN or Infinity 58 if (!unpack_BID64 (&sign_x, &exponent_x, &coefficient_x, x)) { 59 // x is Inf. or NaN or 0 60#ifdef SET_STATUS_FLAGS 61 if ((x & SNAN_MASK64) == SNAN_MASK64) // y is sNaN 62 __set_status_flags (pfpsf, INVALID_EXCEPTION); 63#endif 64 if (coefficient_x) 65 res = coefficient_x & QUIET_MASK64; 66 else { 67 exp64 = (SINT64) exponent_x + (SINT64) n; 68 if(exp64<0) exp64=0; 69 if(exp64>MAX_DECIMAL_EXPONENT) exp64=MAX_DECIMAL_EXPONENT; 70 exponent_x = exp64; 71 res = very_fast_get_BID64 (sign_x, exponent_x, coefficient_x); // 0 72 } 73 BID_RETURN (res); 74 } 75 76 exp64 = (SINT64) exponent_x + (SINT64) n; 77 exponent_x = exp64; 78 79 if ((UINT32) exponent_x <= MAX_DECIMAL_EXPONENT) { 80 res = very_fast_get_BID64 (sign_x, exponent_x, coefficient_x); 81 BID_RETURN (res); 82 } 83 // check for overflow 84 if (exp64 > MAX_DECIMAL_EXPONENT) { 85 // try to normalize coefficient 86 while ((coefficient_x < 1000000000000000ull) 87 && (exp64 > MAX_DECIMAL_EXPONENT)) { 88 // coefficient_x < 10^15, scale by 10 89 coefficient_x = (coefficient_x << 1) + (coefficient_x << 3); 90 exponent_x--; 91 exp64--; 92 } 93 if (exp64 <= MAX_DECIMAL_EXPONENT) { 94 res = very_fast_get_BID64 (sign_x, exponent_x, coefficient_x); 95 BID_RETURN (res); 96 } else 97 exponent_x = 0x7fffffff; // overflow 98 } 99 // exponent < 0 100 // the BID pack routine will round the coefficient 101 rmode = rnd_mode; 102 res = get_BID64 (sign_x, exponent_x, coefficient_x, rmode, pfpsf); 103 BID_RETURN (res); 104 105} 106