1 // SPDX-License-Identifier: GPL-2.0-only 2 /* IEEE754 floating point arithmetic 3 * single precision 4 */ 5 /* 6 * MIPS floating point support 7 * Copyright (C) 1994-2000 Algorithmics Ltd. 8 */ 9 10 #include "ieee754sp.h" 11 #include "ieee754dp.h" 12 ieee754sp_nan_fdp(int xs,u64 xm)13static inline union ieee754sp ieee754sp_nan_fdp(int xs, u64 xm) 14 { 15 return buildsp(xs, SP_EMAX + 1 + SP_EBIAS, 16 xm >> (DP_FBITS - SP_FBITS)); 17 } 18 ieee754sp_fdp(union ieee754dp x)19union ieee754sp ieee754sp_fdp(union ieee754dp x) 20 { 21 union ieee754sp y; 22 u32 rm; 23 24 COMPXDP; 25 COMPYSP; 26 27 EXPLODEXDP; 28 29 ieee754_clearcx(); 30 31 FLUSHXDP; 32 33 switch (xc) { 34 case IEEE754_CLASS_SNAN: 35 x = ieee754dp_nanxcpt(x); 36 EXPLODEXDP; 37 fallthrough; 38 case IEEE754_CLASS_QNAN: 39 y = ieee754sp_nan_fdp(xs, xm); 40 if (!ieee754_csr.nan2008) { 41 EXPLODEYSP; 42 if (!ieee754_class_nan(yc)) 43 y = ieee754sp_indef(); 44 } 45 return y; 46 47 case IEEE754_CLASS_INF: 48 return ieee754sp_inf(xs); 49 50 case IEEE754_CLASS_ZERO: 51 return ieee754sp_zero(xs); 52 53 case IEEE754_CLASS_DNORM: 54 /* can't possibly be sp representable */ 55 ieee754_setcx(IEEE754_UNDERFLOW); 56 ieee754_setcx(IEEE754_INEXACT); 57 if ((ieee754_csr.rm == FPU_CSR_RU && !xs) || 58 (ieee754_csr.rm == FPU_CSR_RD && xs)) 59 return ieee754sp_mind(xs); 60 return ieee754sp_zero(xs); 61 62 case IEEE754_CLASS_NORM: 63 break; 64 } 65 66 /* 67 * Convert from DP_FBITS to SP_FBITS+3 with sticky right shift. 68 */ 69 rm = (xm >> (DP_FBITS - (SP_FBITS + 3))) | 70 ((xm << (64 - (DP_FBITS - (SP_FBITS + 3)))) != 0); 71 72 return ieee754sp_format(xs, xe, rm); 73 } 74