80 lines
1.5 KiB
C
80 lines
1.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/* IEEE754 floating point arithmetic
|
|
* single precision
|
|
*/
|
|
/*
|
|
* MIPS floating point support
|
|
* Copyright (C) 1994-2000 Algorithmics Ltd.
|
|
* Copyright (C) 2017 Imagination Technologies, Ltd.
|
|
* Author: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
|
|
*/
|
|
|
|
#include "ieee754sp.h"
|
|
|
|
union ieee754sp ieee754sp_rint(union ieee754sp x)
|
|
{
|
|
union ieee754sp ret;
|
|
u32 residue;
|
|
int sticky;
|
|
int round;
|
|
int odd;
|
|
|
|
COMPXDP; /* <-- DP needed for 64-bit mantissa tmp */
|
|
|
|
ieee754_clearcx();
|
|
|
|
EXPLODEXSP;
|
|
FLUSHXSP;
|
|
|
|
if (xc == IEEE754_CLASS_SNAN)
|
|
return ieee754sp_nanxcpt(x);
|
|
|
|
if ((xc == IEEE754_CLASS_QNAN) ||
|
|
(xc == IEEE754_CLASS_INF) ||
|
|
(xc == IEEE754_CLASS_ZERO))
|
|
return x;
|
|
|
|
if (xe >= SP_FBITS)
|
|
return x;
|
|
|
|
if (xe < -1) {
|
|
residue = xm;
|
|
round = 0;
|
|
sticky = residue != 0;
|
|
xm = 0;
|
|
} else {
|
|
residue = xm << (xe + 1);
|
|
residue <<= 31 - SP_FBITS;
|
|
round = (residue >> 31) != 0;
|
|
sticky = (residue << 1) != 0;
|
|
xm >>= SP_FBITS - xe;
|
|
}
|
|
|
|
odd = (xm & 0x1) != 0x0;
|
|
|
|
switch (ieee754_csr.rm) {
|
|
case FPU_CSR_RN: /* toward nearest */
|
|
if (round && (sticky || odd))
|
|
xm++;
|
|
break;
|
|
case FPU_CSR_RZ: /* toward zero */
|
|
break;
|
|
case FPU_CSR_RU: /* toward +infinity */
|
|
if ((round || sticky) && !xs)
|
|
xm++;
|
|
break;
|
|
case FPU_CSR_RD: /* toward -infinity */
|
|
if ((round || sticky) && xs)
|
|
xm++;
|
|
break;
|
|
}
|
|
|
|
if (round || sticky)
|
|
ieee754_setcx(IEEE754_INEXACT);
|
|
|
|
ret = ieee754sp_flong(xm);
|
|
SPSIGN(ret) = xs;
|
|
|
|
return ret;
|
|
}
|