diff options
Diffstat (limited to 'arch/mips/math-emu/sp_sub.c')
| -rw-r--r-- | arch/mips/math-emu/sp_sub.c | 87 |
1 files changed, 36 insertions, 51 deletions
diff --git a/arch/mips/math-emu/sp_sub.c b/arch/mips/math-emu/sp_sub.c index e595c6f3d0bb..16c8e9ae63ed 100644 --- a/arch/mips/math-emu/sp_sub.c +++ b/arch/mips/math-emu/sp_sub.c @@ -1,58 +1,44 @@ +// SPDX-License-Identifier: GPL-2.0-only /* IEEE754 floating point arithmetic * single precision */ /* * MIPS floating point support * Copyright (C) 1994-2000 Algorithmics Ltd. - * - * ######################################################################## - * - * This program is free software; you can distribute it and/or modify it - * under the terms of the GNU General Public License (Version 2) as - * published by the Free Software Foundation. - * - * This program is distributed in the hope it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License - * for more details. - * - * You should have received a copy of the GNU General Public License along - * with this program; if not, write to the Free Software Foundation, Inc., - * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA. - * - * ######################################################################## */ - #include "ieee754sp.h" -ieee754sp ieee754sp_sub(ieee754sp x, ieee754sp y) +union ieee754sp ieee754sp_sub(union ieee754sp x, union ieee754sp y) { + int s; + COMPXSP; COMPYSP; EXPLODEXSP; EXPLODEYSP; - CLEARCX; + ieee754_clearcx(); FLUSHXSP; FLUSHYSP; switch (CLPAIR(xc, yc)) { - case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_QNAN): case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_SNAN): - case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_SNAN): case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_SNAN): case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_SNAN): case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_SNAN): case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_SNAN): + return ieee754sp_nanxcpt(y); + + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_SNAN): + case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_QNAN): case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_ZERO): case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_NORM): case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_DNORM): case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF): - SETCX(IEEE754_INVALID_OPERATION); - return ieee754sp_nanxcpt(ieee754sp_indef(), "sub", x, y); + return ieee754sp_nanxcpt(x); case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN): case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN): @@ -68,14 +54,14 @@ ieee754sp ieee754sp_sub(ieee754sp x, ieee754sp y) return x; - /* Infinity handling - */ - + /* + * Infinity handling + */ case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_INF): if (xs != ys) return x; - SETCX(IEEE754_INVALID_OPERATION); - return ieee754sp_xcpt(ieee754sp_indef(), "sub", x, y); + ieee754_setcx(IEEE754_INVALID_OPERATION); + return ieee754sp_indef(); case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_INF): case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_INF): @@ -87,15 +73,14 @@ ieee754sp ieee754sp_sub(ieee754sp x, ieee754sp y) case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_DNORM): return x; - /* Zero handling - */ - + /* + * Zero handling + */ case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO): if (xs != ys) return x; else - return ieee754sp_zero(ieee754_csr.rm == - IEEE754_RD); + return ieee754sp_zero(ieee754_csr.rm == FPU_CSR_RD); case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_ZERO): case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_ZERO): @@ -104,12 +89,12 @@ ieee754sp ieee754sp_sub(ieee754sp x, ieee754sp y) case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_NORM): case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_DNORM): /* quick fix up */ - DPSIGN(y) ^= 1; + SPSIGN(y) ^= 1; return y; case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM): SPDNORMX; - + fallthrough; case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM): SPDNORMY; break; @@ -133,15 +118,19 @@ ieee754sp ieee754sp_sub(ieee754sp x, ieee754sp y) ym <<= 3; if (xe > ye) { - /* have to shift y fraction right to align + /* + * have to shift y fraction right to align */ - int s = xe - ye; - SPXSRSYn(s); + s = xe - ye; + ym = XSPSRS(ym, s); + ye += s; } else if (ye > xe) { - /* have to shift x fraction right to align + /* + * have to shift x fraction right to align */ - int s = ye - xe; - SPXSRSXn(s); + s = ye - xe; + xm = XSPSRS(xm, s); + xe += s; } assert(xe == ye); assert(xe <= SP_EMAX); @@ -150,34 +139,30 @@ ieee754sp ieee754sp_sub(ieee754sp x, ieee754sp y) /* generate 28 bit result of adding two 27 bit numbers */ xm = xm + ym; - xe = xe; - xs = xs; - if (xm >> (SP_MBITS + 1 + 3)) { /* carry out */ + if (xm >> (SP_FBITS + 1 + 3)) { /* carry out */ SPXSRSX1(); /* shift preserving sticky */ } } else { if (xm >= ym) { xm = xm - ym; - xe = xe; - xs = xs; } else { xm = ym - xm; - xe = xe; xs = ys; } if (xm == 0) { - if (ieee754_csr.rm == IEEE754_RD) + if (ieee754_csr.rm == FPU_CSR_RD) return ieee754sp_zero(1); /* round negative inf. => sign = -1 */ else return ieee754sp_zero(0); /* other round modes => sign = 1 */ } /* normalize to rounding precision */ - while ((xm >> (SP_MBITS + 3)) == 0) { + while ((xm >> (SP_FBITS + 3)) == 0) { xm <<= 1; xe--; } } - SPNORMRET2(xs, xe, xm, "sub", x, y); + + return ieee754sp_format(xs, xe, xm); } |