54 lines
955 B
C
54 lines
955 B
C
|
// SPDX-License-Identifier: GPL-2.0-only
|
||
|
|
/* IEEE754 floating point arithmetic
|
||
|
|
* double precision: common utilities
|
||
|
|
*/
|
||
|
|
/*
|
||
|
|
* MIPS floating point support
|
||
|
|
* Copyright (C) 1994-2000 Algorithmics Ltd.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "ieee754dp.h"
|
||
|
|
|
||
|
|
union ieee754dp ieee754dp_flong(s64 x)
|
||
|
|
{
|
||
|
|
u64 xm;
|
||
|
|
int xe;
|
||
|
|
int xs;
|
||
|
|
|
||
|
|
ieee754_clearcx();
|
||
|
|
|
||
|
|
if (x == 0)
|
||
|
|
return ieee754dp_zero(0);
|
||
|
|
if (x == 1 || x == -1)
|
||
|
|
return ieee754dp_one(x < 0);
|
||
|
|
if (x == 10 || x == -10)
|
||
|
|
return ieee754dp_ten(x < 0);
|
||
|
|
|
||
|
|
xs = (x < 0);
|
||
|
|
if (xs) {
|
||
|
|
if (x == (1ULL << 63))
|
||
|
|
xm = (1ULL << 63); /* max neg can't be safely negated */
|
||
|
|
else
|
||
|
|
xm = -x;
|
||
|
|
} else {
|
||
|
|
xm = x;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* normalize */
|
||
|
|
xe = DP_FBITS + 3;
|
||
|
|
if (xm >> (DP_FBITS + 1 + 3)) {
|
||
|
|
/* shunt out overflow bits */
|
||
|
|
while (xm >> (DP_FBITS + 1 + 3)) {
|
||
|
|
XDPSRSX1();
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
/* normalize in grs extended double precision */
|
||
|
|
while ((xm >> (DP_FBITS + 3)) == 0) {
|
||
|
|
xm <<= 1;
|
||
|
|
xe--;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return ieee754dp_format(xs, xe, xm);
|
||
|
|
}
|