diff options
Diffstat (limited to 'arch/mips/math-emu/sp_rint.c')
-rw-r--r-- | arch/mips/math-emu/sp_rint.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/arch/mips/math-emu/sp_rint.c b/arch/mips/math-emu/sp_rint.c new file mode 100644 index 0000000000..d5f75fe215 --- /dev/null +++ b/arch/mips/math-emu/sp_rint.c @@ -0,0 +1,79 @@ +// 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; +} |