diff options
Diffstat (limited to 'arch/mips/math-emu/sp_fdp.c')
-rw-r--r-- | arch/mips/math-emu/sp_fdp.c | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/arch/mips/math-emu/sp_fdp.c b/arch/mips/math-emu/sp_fdp.c new file mode 100644 index 000000000..56417497c --- /dev/null +++ b/arch/mips/math-emu/sp_fdp.c @@ -0,0 +1,73 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* IEEE754 floating point arithmetic + * single precision + */ +/* + * MIPS floating point support + * Copyright (C) 1994-2000 Algorithmics Ltd. + */ + +#include "ieee754sp.h" +#include "ieee754dp.h" + +static inline union ieee754sp ieee754sp_nan_fdp(int xs, u64 xm) +{ + return buildsp(xs, SP_EMAX + 1 + SP_EBIAS, + xm >> (DP_FBITS - SP_FBITS)); +} + +union ieee754sp ieee754sp_fdp(union ieee754dp x) +{ + union ieee754sp y; + u32 rm; + + COMPXDP; + COMPYSP; + + EXPLODEXDP; + + ieee754_clearcx(); + + FLUSHXDP; + + switch (xc) { + case IEEE754_CLASS_SNAN: + x = ieee754dp_nanxcpt(x); + EXPLODEXDP; + fallthrough; + case IEEE754_CLASS_QNAN: + y = ieee754sp_nan_fdp(xs, xm); + if (!ieee754_csr.nan2008) { + EXPLODEYSP; + if (!ieee754_class_nan(yc)) + y = ieee754sp_indef(); + } + return y; + + case IEEE754_CLASS_INF: + return ieee754sp_inf(xs); + + case IEEE754_CLASS_ZERO: + return ieee754sp_zero(xs); + + case IEEE754_CLASS_DNORM: + /* can't possibly be sp representable */ + ieee754_setcx(IEEE754_UNDERFLOW); + ieee754_setcx(IEEE754_INEXACT); + if ((ieee754_csr.rm == FPU_CSR_RU && !xs) || + (ieee754_csr.rm == FPU_CSR_RD && xs)) + return ieee754sp_mind(xs); + return ieee754sp_zero(xs); + + case IEEE754_CLASS_NORM: + break; + } + + /* + * Convert from DP_FBITS to SP_FBITS+3 with sticky right shift. + */ + rm = (xm >> (DP_FBITS - (SP_FBITS + 3))) | + ((xm << (64 - (DP_FBITS - (SP_FBITS + 3)))) != 0); + + return ieee754sp_format(xs, xe, rm); +} |