| /* Copyright (C) 2007-2021 Free Software Foundation, Inc. |
| |
| This file is part of GCC. |
| |
| GCC is free software; you can redistribute it and/or modify it under |
| the terms of the GNU General Public License as published by the Free |
| Software Foundation; either version 3, or (at your option) any later |
| version. |
| |
| GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
| WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| for more details. |
| |
| Under Section 7 of GPL version 3, you are granted additional |
| permissions described in the GCC Runtime Library Exception, version |
| 3.1, as published by the Free Software Foundation. |
| |
| You should have received a copy of the GNU General Public License and |
| a copy of the GCC Runtime Library Exception along with this program; |
| see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include "bid_internal.h" |
| |
| #define MAX_FORMAT_DIGITS 16 |
| #define DECIMAL_EXPONENT_BIAS 398 |
| #define MAX_DECIMAL_EXPONENT 767 |
| |
| #if DECIMAL_CALL_BY_REFERENCE |
| |
| void |
| bid64_scalb (UINT64 * pres, UINT64 * px, |
| int *pn _RND_MODE_PARAM _EXC_FLAGS_PARAM _EXC_MASKS_PARAM |
| _EXC_INFO_PARAM) { |
| UINT64 x; |
| int n; |
| #else |
| |
| UINT64 |
| bid64_scalb (UINT64 x, |
| int n _RND_MODE_PARAM _EXC_FLAGS_PARAM _EXC_MASKS_PARAM |
| _EXC_INFO_PARAM) { |
| #endif |
| UINT64 sign_x, coefficient_x, res; |
| SINT64 exp64; |
| int exponent_x, rmode; |
| |
| #if DECIMAL_CALL_BY_REFERENCE |
| #if !DECIMAL_GLOBAL_ROUNDING |
| _IDEC_round rnd_mode = *prnd_mode; |
| #endif |
| x = *px; |
| n = *pn; |
| #endif |
| |
| // unpack arguments, check for NaN or Infinity |
| if (!unpack_BID64 (&sign_x, &exponent_x, &coefficient_x, x)) { |
| // x is Inf. or NaN or 0 |
| #ifdef SET_STATUS_FLAGS |
| if ((x & SNAN_MASK64) == SNAN_MASK64) // y is sNaN |
| __set_status_flags (pfpsf, INVALID_EXCEPTION); |
| #endif |
| if (coefficient_x) |
| res = coefficient_x & QUIET_MASK64; |
| else { |
| exp64 = (SINT64) exponent_x + (SINT64) n; |
| if(exp64<0) exp64=0; |
| if(exp64>MAX_DECIMAL_EXPONENT) exp64=MAX_DECIMAL_EXPONENT; |
| exponent_x = exp64; |
| res = very_fast_get_BID64 (sign_x, exponent_x, coefficient_x); // 0 |
| } |
| BID_RETURN (res); |
| } |
| |
| exp64 = (SINT64) exponent_x + (SINT64) n; |
| exponent_x = exp64; |
| |
| if ((UINT32) exponent_x <= MAX_DECIMAL_EXPONENT) { |
| res = very_fast_get_BID64 (sign_x, exponent_x, coefficient_x); |
| BID_RETURN (res); |
| } |
| // check for overflow |
| if (exp64 > MAX_DECIMAL_EXPONENT) { |
| // try to normalize coefficient |
| while ((coefficient_x < 1000000000000000ull) |
| && (exp64 > MAX_DECIMAL_EXPONENT)) { |
| // coefficient_x < 10^15, scale by 10 |
| coefficient_x = (coefficient_x << 1) + (coefficient_x << 3); |
| exponent_x--; |
| exp64--; |
| } |
| if (exp64 <= MAX_DECIMAL_EXPONENT) { |
| res = very_fast_get_BID64 (sign_x, exponent_x, coefficient_x); |
| BID_RETURN (res); |
| } else |
| exponent_x = 0x7fffffff; // overflow |
| } |
| // exponent < 0 |
| // the BID pack routine will round the coefficient |
| rmode = rnd_mode; |
| res = get_BID64 (sign_x, exponent_x, coefficient_x, rmode, pfpsf); |
| BID_RETURN (res); |
| |
| } |