87 lines
2.6 KiB
C
87 lines
2.6 KiB
C
/* Copyright (C) 2007 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 2, or (at your option) any later
|
|
version.
|
|
|
|
In addition to the permissions in the GNU General Public License, the
|
|
Free Software Foundation gives you unlimited permission to link the
|
|
compiled version of this file into combinations with other programs,
|
|
and to distribute those combinations without any restriction coming
|
|
from the use of this file. (The General Public License restrictions
|
|
do apply in other respects; for example, they cover modification of
|
|
the file, and distribution when not linked into a combine
|
|
executable.)
|
|
|
|
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.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with GCC; see the file COPYING. If not, write to the Free
|
|
Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
|
|
02110-1301, USA. */
|
|
|
|
#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;
|
|
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
|
|
res.w[1] = x.w[1];
|
|
res.w[0] = x.w[0];
|
|
BID_RETURN (res);
|
|
}
|
|
|
|
exponent_x += n;
|
|
|
|
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 (exponent_x > 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--;
|
|
}
|
|
while (CX.w[1] < 0x314dc6448d93ull
|
|
&& exponent_x > MAX_DECIMAL_EXPONENT_128);
|
|
|
|
if (exponent_x <= MAX_DECIMAL_EXPONENT_128) {
|
|
get_BID128_very_fast (&res, sign_x, exponent_x, CX);
|
|
BID_RETURN (res);
|
|
}
|
|
}
|
|
}
|
|
// 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);
|
|
|
|
}
|