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/* Copyright (C) 2007, 2009 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_div_macros.h"
BID128_FUNCTION_ARG2_NORND_CUSTOMRESTYPE (UINT128, bid128_rem, x, y)
UINT256 P256;
UINT128 CX, CY, CX2, CQ, CR, T, CXS, P128, res;
UINT64 sign_x, sign_y, valid_y;
SINT64 D;
int_float f64, fx;
int exponent_x, exponent_y, diff_expon, bin_expon_cx, scale,
scale0;
// unpack arguments, check for NaN or Infinity
valid_y = unpack_BID128_value (&sign_y, &exponent_y, &CY, y);
if (!unpack_BID128_value (&sign_x, &exponent_x, &CX, x)) {
#ifdef SET_STATUS_FLAGS
if ((y.w[1] & SNAN_MASK64) == SNAN_MASK64) // y is sNaN
__set_status_flags (pfpsf, INVALID_EXCEPTION);
#endif
// test if x is NaN
if ((x.w[1] & 0x7c00000000000000ull) == 0x7c00000000000000ull) {
#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];
BID_RETURN (res);
}
// x is Infinity?
if ((x.w[1] & 0x7800000000000000ull) == 0x7800000000000000ull) {
// check if y is Inf.
if (((y.w[1] & 0x7c00000000000000ull) != 0x7c00000000000000ull))
// return NaN
{
#ifdef SET_STATUS_FLAGS
// set status flags
__set_status_flags (pfpsf, INVALID_EXCEPTION);
#endif
res.w[1] = 0x7c00000000000000ull;
res.w[0] = 0;
BID_RETURN (res);
}
}
// x is 0
if ((!CY.w[1]) && (!CY.w[0])) {
#ifdef SET_STATUS_FLAGS
// set status flags
__set_status_flags (pfpsf, INVALID_EXCEPTION);
#endif
// x=y=0, return NaN
res.w[1] = 0x7c00000000000000ull;
res.w[0] = 0;
BID_RETURN (res);
}
if (valid_y || ((y.w[1] & NAN_MASK64) == INFINITY_MASK64)) {
// return 0
if ((exponent_x > exponent_y)
&& ((y.w[1] & NAN_MASK64) != INFINITY_MASK64))
exponent_x = exponent_y;
res.w[1] = sign_x | (((UINT64) exponent_x) << 49);
res.w[0] = 0;
BID_RETURN (res);
}
}
if (!valid_y) {
// y is Inf. or NaN
// test if y is NaN
if ((y.w[1] & 0x7c00000000000000ull) == 0x7c00000000000000ull) {
#ifdef SET_STATUS_FLAGS
if ((y.w[1] & SNAN_MASK64) == SNAN_MASK64) // y is sNaN
__set_status_flags (pfpsf, INVALID_EXCEPTION);
#endif
res.w[1] = CY.w[1] & QUIET_MASK64;
res.w[0] = CY.w[0];
BID_RETURN (res);
}
// y is Infinity?
if ((y.w[1] & 0x7800000000000000ull) == 0x7800000000000000ull) {
// return x
res.w[1] = x.w[1];
res.w[0] = x.w[0];
BID_RETURN (res);
}
// y is 0
#ifdef SET_STATUS_FLAGS
// set status flags
__set_status_flags (pfpsf, INVALID_EXCEPTION);
#endif
res.w[1] = 0x7c00000000000000ull;
res.w[0] = 0;
BID_RETURN (res);
}
diff_expon = exponent_x - exponent_y;
if (diff_expon <= 0) {
diff_expon = -diff_expon;
if (diff_expon > 34) {
// |x|<|y| in this case
res = x;
BID_RETURN (res);
}
// set exponent of y to exponent_x, scale coefficient_y
T = power10_table_128[diff_expon];
__mul_128x128_to_256 (P256, CY, T);
if (P256.w[2] || P256.w[3]) {
// |x|<|y| in this case
res = x;
BID_RETURN (res);
}
CX2.w[1] = (CX.w[1] << 1) | (CX.w[0] >> 63);
CX2.w[0] = CX.w[0] << 1;
if (__unsigned_compare_ge_128 (P256, CX2)) {
// |x|<|y| in this case
res = x;
BID_RETURN (res);
}
P128.w[0] = P256.w[0];
P128.w[1] = P256.w[1];
__div_128_by_128 (&CQ, &CR, CX, P128);
CX2.w[1] = (CR.w[1] << 1) | (CR.w[0] >> 63);
CX2.w[0] = CR.w[0] << 1;
if ((__unsigned_compare_gt_128 (CX2, P256))
|| (CX2.w[1] == P256.w[1] && CX2.w[0] == P256.w[0]
&& (CQ.w[0] & 1))) {
__sub_128_128 (CR, P256, CR);
sign_x ^= 0x8000000000000000ull;
}
get_BID128_very_fast (&res, sign_x, exponent_x, CR);
BID_RETURN (res);
}
// 2^64
f64.i = 0x5f800000;
scale0 = 38;
if (!CY.w[1])
scale0 = 34;
while (diff_expon > 0) {
// get number of digits in CX and scale=38-digits
// fx ~ CX
fx.d = (float) CX.w[1] * f64.d + (float) CX.w[0];
bin_expon_cx = ((fx.i >> 23) & 0xff) - 0x7f;
scale = scale0 - estimate_decimal_digits[bin_expon_cx];
// scale = 38-estimate_decimal_digits[bin_expon_cx];
D = CX.w[1] - power10_index_binexp_128[bin_expon_cx].w[1];
if (D > 0
|| (!D && CX.w[0] >= power10_index_binexp_128[bin_expon_cx].w[0]))
scale--;
if (diff_expon >= scale)
diff_expon -= scale;
else {
scale = diff_expon;
diff_expon = 0;
}
T = power10_table_128[scale];
__mul_128x128_low (CXS, CX, T);
__div_128_by_128 (&CQ, &CX, CXS, CY);
// check for remainder == 0
if (!CX.w[1] && !CX.w[0]) {
get_BID128_very_fast (&res, sign_x, exponent_y, CX);
BID_RETURN (res);
}
}
CX2.w[1] = (CX.w[1] << 1) | (CX.w[0] >> 63);
CX2.w[0] = CX.w[0] << 1;
if ((__unsigned_compare_gt_128 (CX2, CY))
|| (CX2.w[1] == CY.w[1] && CX2.w[0] == CY.w[0] && (CQ.w[0] & 1))) {
__sub_128_128 (CX, CY, CX);
sign_x ^= 0x8000000000000000ull;
}
get_BID128_very_fast (&res, sign_x, exponent_y, CX);
BID_RETURN (res);
}
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