Eine aufbereitete Darstellung der Quelle

 
     
 
 
Anforderungen  |   Konzepte  |   Entwurf  |   Entwicklung  |   Qualitätssicherung  |   Lebenszyklus  |   Steuerung
 
 
 
 
Benutzer

products/Sources/formale Sprachen/C/Firefox/layout/reftests/svg/   (Firefox Browser Version 153.0.1©)  Datei vom 27.6.2026 mit Größe 1 kB image not shown  

Bilddatei

ieee754dp.c


products/Sources/formale Sprachen/C/Linux/arch/mips/math-emu/ieee754dp.c

// 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. */ #include #include "ieee754dp.h" int ieee754dp_class(union ieee754dp x) { COMPXDP; EXPLODEXDP; return xc; } static inline int ieee754dp_isnan(union ieee754dp x) { return ieee754_class_nan(ieee754dp_class(x)); } static inline int ieee754dp_issnan(union ieee754dp x) { int qbit; assert(ieee754dp_isnan(x)); qbit = (DPMANT(x) & DP_MBIT(DP_FBITS - 1)) == DP_MBIT(DP_FBITS - 1); return ieee754_csr.nan2008 ^ qbit; } /* * Raise the Invalid Operation IEEE 754 exception * and convert the signaling NaN supplied to a quiet NaN. */ union ieee754dp __cold ieee754dp_nanxcpt(union ieee754dp r) { assert(ieee754dp_issnan(r)); ieee754_setcx(IEEE754_INVALID_OPERATION); if (ieee754_csr.nan2008) { DPMANT(r) |= DP_MBIT(DP_FBITS - 1); } else { DPMANT(r) &= ~DP_MBIT(DP_FBITS - 1); if (!ieee754dp_isnan(r)) DPMANT(r) |= DP_MBIT(DP_FBITS - 2); } return r; } static u64 ieee754dp_get_rounding(int sn, u64 xm) { /* inexact must round of 3 bits */ if (xm & (DP_MBIT(3) - 1)) { switch (ieee754_csr.rm) { case FPU_CSR_RZ: break; case FPU_CSR_RN: xm += 0x3 + ((xm >> 3) & 1); /* xm += (xm&0x8)?0x4:0x3 */ break; case FPU_CSR_RU: /* toward +Infinity */ if (!sn) /* ?? */ xm += 0x8; break; case FPU_CSR_RD: /* toward -Infinity */ if (sn) /* ?? */ xm += 0x8; break; } } return xm; } /* generate a normal/denormal number with over,under handling * sn is sign * xe is an unbiased exponent * xm is 3bit extended precision value. */ union ieee754dp ieee754dp_format(int sn, int xe, u64 xm) { assert(xm); /* we don't gen exact zeros (probably should) */ assert((xm >> (DP_FBITS + 1 + 3)) == 0); /* no excess */ assert(xm & (DP_HIDDEN_BIT << 3)); if (xe < DP_EMIN) { /* strip lower bits */ int es = DP_EMIN - xe; if (ieee754_csr.nod) { ieee754_setcx(IEEE754_UNDERFLOW); ieee754_setcx(IEEE754_INEXACT); switch(ieee754_csr.rm) { case FPU_CSR_RN: case FPU_CSR_RZ: return ieee754dp_zero(sn); case FPU_CSR_RU: /* toward +Infinity */ if (sn == 0) return ieee754dp_min(0); else return ieee754dp_zero(1); case FPU_CSR_RD: /* toward -Infinity */ if (sn == 0) return ieee754dp_zero(0); else return ieee754dp_min(1); } } if (xe == DP_EMIN - 1 && ieee754dp_get_rounding(sn, xm) >> (DP_FBITS + 1 + 3)) { /* Not tiny after rounding */ ieee754_setcx(IEEE754_INEXACT); xm = ieee754dp_get_rounding(sn, xm); xm >>= 1; /* Clear grs bits */ xm &= ~(DP_MBIT(3) - 1); xe++; } else { /* sticky right shift es bits */ xm = XDPSRS(xm, es); xe += es; assert((xm & (DP_HIDDEN_BIT << 3)) == 0); assert(xe == DP_EMIN); } } if (xm & (DP_MBIT(3) - 1)) { ieee754_setcx(IEEE754_INEXACT); if ((xm & (DP_HIDDEN_BIT << 3)) == 0) { ieee754_setcx(IEEE754_UNDERFLOW); } /* inexact must round of 3 bits */ xm = ieee754dp_get_rounding(sn, xm); /* adjust exponent for rounding add overflowing */ if (xm >> (DP_FBITS + 3 + 1)) { /* add causes mantissa overflow */ xm >>= 1; xe++; } } /* strip grs bits */ xm >>= 3; assert((xm >> (DP_FBITS + 1)) == 0); /* no excess */ assert(xe >= DP_EMIN); if (xe > DP_EMAX) { ieee754_setcx(IEEE754_OVERFLOW); ieee754_setcx(IEEE754_INEXACT); /* -O can be table indexed by (rm,sn) */ switch (ieee754_csr.rm) { case FPU_CSR_RN: return ieee754dp_inf(sn); case FPU_CSR_RZ: return ieee754dp_max(sn); case FPU_CSR_RU: /* toward +Infinity */ if (sn == 0) return ieee754dp_inf(0); else return ieee754dp_max(1); case FPU_CSR_RD: /* toward -Infinity */ if (sn == 0) return ieee754dp_max(0); else return ieee754dp_inf(1); } } /* gen norm/denorm/zero */ if ((xm & DP_HIDDEN_BIT) == 0) { /* we underflow (tiny/zero) */ assert(xe == DP_EMIN); if (ieee754_csr.mx & IEEE754_UNDERFLOW) ieee754_setcx(IEEE754_UNDERFLOW); return builddp(sn, DP_EMIN - 1 + DP_EBIAS, xm); } else { assert((xm >> (DP_FBITS + 1)) == 0); /* no excess */ assert(xm & DP_HIDDEN_BIT); return builddp(sn, xe + DP_EBIAS, xm & ~DP_HIDDEN_BIT); } }

                                                                                                                                                                                                                                                                                                                                                                                                     

Neuigkeiten

     Aktuelles
     Motto des Tages

Open Source Software

     Quellcodebibliothek
     Eigene Quellcodes
     Fremde Quellcodes
     Suchen
Jenseits des Üblichen ....
    

Besucherstatistik

Besucherstatistik
Statistik
#Sources=1126438
#Domains=1897691