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Diffstat (limited to '')
| -rw-r--r-- | arch/mips/math-emu/dp_rint.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/arch/mips/math-emu/dp_rint.c b/arch/mips/math-emu/dp_rint.c new file mode 100644 index 000000000..7f30b7a30 --- /dev/null +++ b/arch/mips/math-emu/dp_rint.c @@ -0,0 +1,78 @@ +// 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. + * Copyright (C) 2017 Imagination Technologies, Ltd. + * Author: Aleksandar Markovic <aleksandar.markovic@imgtec.com> + */ + +#include "ieee754dp.h" + +union ieee754dp ieee754dp_rint(union ieee754dp x) +{ + union ieee754dp ret; + u64 residue; + int sticky; + int round; + int odd; + + COMPXDP; + + ieee754_clearcx(); + + EXPLODEXDP; + FLUSHXDP; + + if (xc == IEEE754_CLASS_SNAN) + return ieee754dp_nanxcpt(x); + + if ((xc == IEEE754_CLASS_QNAN) || + (xc == IEEE754_CLASS_INF) || + (xc == IEEE754_CLASS_ZERO)) + return x; + + if (xe >= DP_FBITS) + return x; + + if (xe < -1) { + residue = xm; + round = 0; + sticky = residue != 0; + xm = 0; + } else { + residue = xm << (64 - DP_FBITS + xe); + round = (residue >> 63) != 0; + sticky = (residue << 1) != 0; + xm >>= DP_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 = ieee754dp_flong(xm); + DPSIGN(ret) = xs; + + return ret; +} |