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[/] [openrisc/] [trunk/] [gnu-old/] [gcc-4.2.2/] [gcc/] [config/] [m68k/] [fpgnulib.c] - Rev 154
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/* This is a stripped down version of floatlib.c. It supplies only those functions which exist in libgcc, but for which there is not assembly language versions in m68k/lb1sf68.asm. It also includes simplistic support for extended floats (by working in double precision). You must compile this file again with -DEXTFLOAT to get this support. */ /* ** gnulib support for software floating point. ** Copyright (C) 1991 by Pipeline Associates, Inc. All rights reserved. ** Permission is granted to do *anything* you want with this file, ** commercial or otherwise, provided this message remains intact. So there! ** I would appreciate receiving any updates/patches/changes that anyone ** makes, and am willing to be the repository for said changes (am I ** making a big mistake?). ** ** Pat Wood ** Pipeline Associates, Inc. ** pipeline!phw@motown.com or ** sun!pipeline!phw or ** uunet!motown!pipeline!phw ** ** 05/01/91 -- V1.0 -- first release to gcc mailing lists ** 05/04/91 -- V1.1 -- added float and double prototypes and return values ** -- fixed problems with adding and subtracting zero ** -- fixed rounding in truncdfsf2 ** -- fixed SWAP define and tested on 386 */ /* ** The following are routines that replace the gnulib soft floating point ** routines that are called automatically when -msoft-float is selected. ** The support single and double precision IEEE format, with provisions ** for byte-swapped machines (tested on 386). Some of the double-precision ** routines work at full precision, but most of the hard ones simply punt ** and call the single precision routines, producing a loss of accuracy. ** long long support is not assumed or included. ** Overall accuracy is close to IEEE (actually 68882) for single-precision ** arithmetic. I think there may still be a 1 in 1000 chance of a bit ** being rounded the wrong way during a multiply. I'm not fussy enough to ** bother with it, but if anyone is, knock yourself out. ** ** Efficiency has only been addressed where it was obvious that something ** would make a big difference. Anyone who wants to do this right for ** best speed should go in and rewrite in assembler. ** ** I have tested this only on a 68030 workstation and 386/ix integrated ** in with -msoft-float. */ /* the following deal with IEEE single-precision numbers */ #define EXCESS 126L #define SIGNBIT 0x80000000L #define HIDDEN (1L << 23L) #define SIGN(fp) ((fp) & SIGNBIT) #define EXP(fp) (((fp) >> 23L) & 0xFF) #define MANT(fp) (((fp) & 0x7FFFFFL) | HIDDEN) #define PACK(s,e,m) ((s) | ((e) << 23L) | (m)) /* the following deal with IEEE double-precision numbers */ #define EXCESSD 1022L #define HIDDEND (1L << 20L) #define EXPDBITS 11 #define EXPDMASK 0x7FFL #define EXPD(fp) (((fp.l.upper) >> 20L) & 0x7FFL) #define SIGND(fp) ((fp.l.upper) & SIGNBIT) #define MANTD(fp) (((((fp.l.upper) & 0xFFFFF) | HIDDEND) << 10) | \ (fp.l.lower >> 22)) #define MANTDMASK 0xFFFFFL /* mask of upper part */ /* the following deal with IEEE extended-precision numbers */ #define EXCESSX 16382L #define HIDDENX (1L << 31L) #define EXPXBITS 15 #define EXPXMASK 0x7FFF #define EXPX(fp) (((fp.l.upper) >> 16) & EXPXMASK) #define SIGNX(fp) ((fp.l.upper) & SIGNBIT) #define MANTXMASK 0x7FFFFFFFL /* mask of upper part */ union double_long { double d; struct { long upper; unsigned long lower; } l; }; union float_long { float f; long l; }; union long_double_long { long double ld; struct { long upper; unsigned long middle; unsigned long lower; } l; }; #ifndef EXTFLOAT int __unordsf2(float a, float b) { union float_long fl; fl.f = a; if (EXP(fl.l) == EXP(~0u) && (MANT(fl.l) & ~HIDDEN) != 0) return 1; fl.f = b; if (EXP(fl.l) == EXP(~0u) && (MANT(fl.l) & ~HIDDEN) != 0) return 1; return 0; } int __unorddf2(double a, double b) { union double_long dl; dl.d = a; if (EXPD(dl) == EXPDMASK && ((dl.l.upper & MANTDMASK) != 0 || dl.l.lower != 0)) return 1; dl.d = b; if (EXPD(dl) == EXPDMASK && ((dl.l.upper & MANTDMASK) != 0 || dl.l.lower != 0)) return 1; return 0; } /* convert unsigned int to double */ double __floatunsidf (unsigned long a1) { long exp = 32 + EXCESSD; union double_long dl; if (!a1) { dl.l.upper = dl.l.lower = 0; return dl.d; } while (a1 < 0x2000000L) { a1 <<= 4; exp -= 4; } while (a1 < 0x80000000L) { a1 <<= 1; exp--; } /* pack up and go home */ dl.l.upper = exp << 20L; dl.l.upper |= (a1 >> 11L) & ~HIDDEND; dl.l.lower = a1 << 21L; return dl.d; } /* convert int to double */ double __floatsidf (long a1) { long sign = 0, exp = 31 + EXCESSD; union double_long dl; if (!a1) { dl.l.upper = dl.l.lower = 0; return dl.d; } if (a1 < 0) { sign = SIGNBIT; a1 = (long)-(unsigned long)a1; if (a1 < 0) { dl.l.upper = SIGNBIT | ((32 + EXCESSD) << 20L); dl.l.lower = 0; return dl.d; } } while (a1 < 0x1000000L) { a1 <<= 4; exp -= 4; } while (a1 < 0x40000000L) { a1 <<= 1; exp--; } /* pack up and go home */ dl.l.upper = sign; dl.l.upper |= exp << 20L; dl.l.upper |= (a1 >> 10L) & ~HIDDEND; dl.l.lower = a1 << 22L; return dl.d; } /* convert unsigned int to float */ float __floatunsisf (unsigned long l) { double foo = __floatunsidf (l); return foo; } /* convert int to float */ float __floatsisf (long l) { double foo = __floatsidf (l); return foo; } /* convert float to double */ double __extendsfdf2 (float a1) { register union float_long fl1; register union double_long dl; register long exp; register long mant; fl1.f = a1; dl.l.upper = SIGN (fl1.l); if ((fl1.l & ~SIGNBIT) == 0) { dl.l.lower = 0; return dl.d; } exp = EXP(fl1.l); mant = MANT (fl1.l) & ~HIDDEN; if (exp == 0) { /* Denormal. */ exp = 1; while (!(mant & HIDDEN)) { mant <<= 1; exp--; } mant &= ~HIDDEN; } exp = exp - EXCESS + EXCESSD; dl.l.upper |= exp << 20; dl.l.upper |= mant >> 3; dl.l.lower = mant << 29; return dl.d; } /* convert double to float */ float __truncdfsf2 (double a1) { register long exp; register long mant; register union float_long fl; register union double_long dl1; dl1.d = a1; if ((dl1.l.upper & ~SIGNBIT) == 0 && !dl1.l.lower) { fl.l = SIGND(dl1); return fl.f; } exp = EXPD (dl1) - EXCESSD + EXCESS; /* shift double mantissa 6 bits so we can round */ mant = MANTD (dl1) >> 6; /* Check for underflow and denormals. */ if (exp <= 0) { if (exp < -24) mant = 0; else mant >>= 1 - exp; exp = 0; } /* now round and shift down */ mant += 1; mant >>= 1; /* did the round overflow? */ if (mant & 0xFF000000L) { mant >>= 1; exp++; } mant &= ~HIDDEN; /* pack up and go home */ fl.l = PACK (SIGND (dl1), exp, mant); return (fl.f); } /* convert double to int */ long __fixdfsi (double a1) { register union double_long dl1; register long exp; register long l; dl1.d = a1; if (!dl1.l.upper && !dl1.l.lower) return 0; exp = EXPD (dl1) - EXCESSD - 31; l = MANTD (dl1); if (exp > 0) { /* Return largest integer. */ return SIGND (dl1) ? 0x80000000L : 0x7fffffffL; } if (exp <= -32) return 0; /* shift down until exp = 0 */ if (exp < 0) l >>= -exp; return (SIGND (dl1) ? -l : l); } /* convert float to int */ long __fixsfsi (float a1) { double foo = a1; return __fixdfsi (foo); } #else /* EXTFLOAT */ /* Primitive extended precision floating point support. We assume all numbers are normalized, don't do any rounding, etc. */ /* Prototypes for the above in case we use them. */ double __floatunsidf (unsigned long); double __floatsidf (long); float __floatsisf (long); double __extendsfdf2 (float); float __truncdfsf2 (double); long __fixdfsi (double); long __fixsfsi (float); int __unordxf2(long double a, long double b) { union long_double_long ldl; ldl.ld = a; if (EXPX(ldl) == EXPXMASK && ((ldl.l.middle & MANTXMASK) != 0 || ldl.l.lower != 0)) return 1; ldl.ld = b; if (EXPX(ldl) == EXPXMASK && ((ldl.l.middle & MANTXMASK) != 0 || ldl.l.lower != 0)) return 1; return 0; } /* convert double to long double */ long double __extenddfxf2 (double d) { register union double_long dl; register union long_double_long ldl; register long exp; dl.d = d; /*printf ("dfxf in: %g\n", d);*/ ldl.l.upper = SIGND (dl); if ((dl.l.upper & ~SIGNBIT) == 0 && !dl.l.lower) { ldl.l.middle = 0; ldl.l.lower = 0; return ldl.ld; } exp = EXPD (dl) - EXCESSD + EXCESSX; ldl.l.upper |= exp << 16; ldl.l.middle = HIDDENX; /* 31-20: # mantissa bits in ldl.l.middle - # mantissa bits in dl.l.upper */ ldl.l.middle |= (dl.l.upper & MANTDMASK) << (31 - 20); /* 1+20: explicit-integer-bit + # mantissa bits in dl.l.upper */ ldl.l.middle |= dl.l.lower >> (1 + 20); /* 32 - 21: # bits of dl.l.lower in ldl.l.middle */ ldl.l.lower = dl.l.lower << (32 - 21); /*printf ("dfxf out: %s\n", dumpxf (ldl.ld));*/ return ldl.ld; } /* convert long double to double */ double __truncxfdf2 (long double ld) { register long exp; register union double_long dl; register union long_double_long ldl; ldl.ld = ld; /*printf ("xfdf in: %s\n", dumpxf (ld));*/ dl.l.upper = SIGNX (ldl); if ((ldl.l.upper & ~SIGNBIT) == 0 && !ldl.l.middle && !ldl.l.lower) { dl.l.lower = 0; return dl.d; } exp = EXPX (ldl) - EXCESSX + EXCESSD; /* ??? quick and dirty: keep `exp' sane */ if (exp >= EXPDMASK) exp = EXPDMASK - 1; dl.l.upper |= exp << (32 - (EXPDBITS + 1)); /* +1-1: add one for sign bit, but take one off for explicit-integer-bit */ dl.l.upper |= (ldl.l.middle & MANTXMASK) >> (EXPDBITS + 1 - 1); dl.l.lower = (ldl.l.middle & MANTXMASK) << (32 - (EXPDBITS + 1 - 1)); dl.l.lower |= ldl.l.lower >> (EXPDBITS + 1 - 1); /*printf ("xfdf out: %g\n", dl.d);*/ return dl.d; } /* convert a float to a long double */ long double __extendsfxf2 (float f) { long double foo = __extenddfxf2 (__extendsfdf2 (f)); return foo; } /* convert a long double to a float */ float __truncxfsf2 (long double ld) { float foo = __truncdfsf2 (__truncxfdf2 (ld)); return foo; } /* convert an int to a long double */ long double __floatsixf (long l) { double foo = __floatsidf (l); return foo; } /* convert an unsigned int to a long double */ long double __floatunsixf (unsigned long l) { double foo = __floatunsidf (l); return foo; } /* convert a long double to an int */ long __fixxfsi (long double ld) { long foo = __fixdfsi ((double) ld); return foo; } /* The remaining provide crude math support by working in double precision. */ long double __addxf3 (long double x1, long double x2) { return (double) x1 + (double) x2; } long double __subxf3 (long double x1, long double x2) { return (double) x1 - (double) x2; } long double __mulxf3 (long double x1, long double x2) { return (double) x1 * (double) x2; } long double __divxf3 (long double x1, long double x2) { return (double) x1 / (double) x2; } long double __negxf2 (long double x1) { return - (double) x1; } long __cmpxf2 (long double x1, long double x2) { return __cmpdf2 ((double) x1, (double) x2); } long __eqxf2 (long double x1, long double x2) { return __cmpdf2 ((double) x1, (double) x2); } long __nexf2 (long double x1, long double x2) { return __cmpdf2 ((double) x1, (double) x2); } long __ltxf2 (long double x1, long double x2) { return __cmpdf2 ((double) x1, (double) x2); } long __lexf2 (long double x1, long double x2) { return __cmpdf2 ((double) x1, (double) x2); } long __gtxf2 (long double x1, long double x2) { return __cmpdf2 ((double) x1, (double) x2); } long __gexf2 (long double x1, long double x2) { return __cmpdf2 ((double) x1, (double) x2); } #endif /* EXTFLOAT */
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