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- /* Copyright (C) 2007-2022 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/>. */
- #define BID_128RES
- #include "bid_internal.h"
- #define DECIMAL_EXPONENT_BIAS_128 6176
- #define MAX_DECIMAL_EXPONENT_128 12287
- BID128_FUNCTION_ARG128_ARGTYPE2 (bid128_scalb, x, int, n)
- UINT128 CX, CX2, CX8, res;
- SINT64 exp64;
- UINT64 sign_x;
- int exponent_x, rmode;
- // unpack arguments, check for NaN or Infinity
- if (!unpack_BID128_value (&sign_x, &exponent_x, &CX, x)) {
- // x is Inf. or NaN or 0
- #ifdef SET_STATUS_FLAGS
- if ((x.w[1] & SNAN_MASK64) == SNAN_MASK64) // y is sNaN
- __set_status_flags (pfpsf, INVALID_EXCEPTION);
- #endif
- res.w[1] = CX.w[1] & QUIET_MASK64;
- res.w[0] = CX.w[0];
- if (!CX.w[1]) {
- exp64 = (SINT64) exponent_x + (SINT64) n;
- if(exp64<0) exp64=0;
- if(exp64>MAX_DECIMAL_EXPONENT_128) exp64=MAX_DECIMAL_EXPONENT_128;
- exponent_x = exp64;
- get_BID128_very_fast (&res, sign_x, exponent_x, CX);
- }
- BID_RETURN (res);
- }
- exp64 = (SINT64) exponent_x + (SINT64) n;
- exponent_x = exp64;
- if ((UINT32) exponent_x <= MAX_DECIMAL_EXPONENT_128) {
- get_BID128_very_fast (&res, sign_x, exponent_x, CX);
- BID_RETURN (res);
- }
- // check for overflow
- if (exp64 > MAX_DECIMAL_EXPONENT_128) {
- if (CX.w[1] < 0x314dc6448d93ull) {
- // try to normalize coefficient
- do {
- CX8.w[1] = (CX.w[1] << 3) | (CX.w[0] >> 61);
- CX8.w[0] = CX.w[0] << 3;
- CX2.w[1] = (CX.w[1] << 1) | (CX.w[0] >> 63);
- CX2.w[0] = CX.w[0] << 1;
- __add_128_128 (CX, CX2, CX8);
- exponent_x--;
- exp64--;
- }
- while (CX.w[1] < 0x314dc6448d93ull
- && exp64 > MAX_DECIMAL_EXPONENT_128);
- }
- if (exp64 <= MAX_DECIMAL_EXPONENT_128) {
- get_BID128_very_fast (&res, sign_x, exponent_x, CX);
- BID_RETURN (res);
- } else
- exponent_x = 0x7fffffff; // overflow
- }
- // exponent < 0
- // the BID pack routine will round the coefficient
- rmode = rnd_mode;
- get_BID128 (&res, sign_x, exponent_x, CX, (unsigned int *) &rmode,
- pfpsf);
- BID_RETURN (res);
- }
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