+++ /dev/null
-/*
-** libgcc 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?).
-
-Warning! Only single-precision is actually implemented. This file
-won't really be much use until double-precision is supported.
-
-However, once that is done, this file might make possible
-cross-compilation for an IEEE target machine from a non-IEEE
-host such as a VAX.
-
-If you'd like to work on completing this, please talk to rms@gnu.ai.mit.edu.
-
---> Double precision floating support added by James Carlson on 20 April 1998.
-
-**
-** 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 libgcc 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 126
-#define SIGNBIT 0x80000000
-#define HIDDEN (1 << 23)
-#define SIGN(fp) ((fp) & SIGNBIT)
-#define EXP(fp) (((fp) >> 23) & 0xFF)
-#define MANT(fp) (((fp) & 0x7FFFFF) | HIDDEN)
-#define PACK(s,e,m) ((s) | ((e) << 23) | (m))
-
-/* the following deal with IEEE double-precision numbers */
-#define EXCESSD 1022
-#define HIDDEND (1 << 20)
-#define EXPD(fp) (((fp.l.upper) >> 20) & 0x7FF)
-#define SIGND(fp) ((fp.l.upper) & SIGNBIT)
-#define MANTD(fp) (((((fp.l.upper) & 0xFFFFF) | HIDDEND) << 10) | \
- (fp.l.lower >> 22))
-#define HIDDEND_LL ((long long)1 << 52)
-#define MANTD_LL(fp) ((fp.ll & (HIDDEND_LL-1)) | HIDDEND_LL)
-#define PACKD_LL(s,e,m) (((long long)((s)+((e)<<20))<<32)|(m))
-
-/* define SWAP for 386/960 reverse-byte-order brain-damaged CPUs */
-union double_long {
- double d;
-#ifdef SWAP
- struct {
- unsigned long lower;
- long upper;
- } l;
-#else
- struct {
- long upper;
- unsigned long lower;
- } l;
-#endif
- long long ll;
-};
-
-union float_long
- {
- float f;
- long l;
- };
-
-/* add two floats */
-float
-__addsf3 (float a1, float a2)
-{
- long mant1, mant2;
- union float_long fl1, fl2;
- int exp1, exp2;
- int sign = 0;
-
- fl1.f = a1;
- fl2.f = a2;
-
- /* check for zero args */
- if (!fl1.l) {
- fl1.f = fl2.f;
- goto test_done;
- }
- if (!fl2.l)
- goto test_done;
-
- exp1 = EXP (fl1.l);
- exp2 = EXP (fl2.l);
-
- if (exp1 > exp2 + 25)
- goto test_done;
- if (exp2 > exp1 + 25) {
- fl1.f = fl2.f;
- goto test_done;
- }
-
- /* do everything in excess precision so's we can round later */
- mant1 = MANT (fl1.l) << 6;
- mant2 = MANT (fl2.l) << 6;
-
- if (SIGN (fl1.l))
- mant1 = -mant1;
- if (SIGN (fl2.l))
- mant2 = -mant2;
-
- if (exp1 > exp2)
- {
- mant2 >>= exp1 - exp2;
- }
- else
- {
- mant1 >>= exp2 - exp1;
- exp1 = exp2;
- }
- mant1 += mant2;
-
- if (mant1 < 0)
- {
- mant1 = -mant1;
- sign = SIGNBIT;
- }
- else if (!mant1) {
- fl1.f = 0;
- goto test_done;
- }
-
- /* normalize up */
- while (!(mant1 & 0xE0000000))
- {
- mant1 <<= 1;
- exp1--;
- }
-
- /* normalize down? */
- if (mant1 & (1 << 30))
- {
- mant1 >>= 1;
- exp1++;
- }
-
- /* round to even */
- mant1 += (mant1 & 0x40) ? 0x20 : 0x1F;
-
- /* normalize down? */
- if (mant1 & (1 << 30))
- {
- mant1 >>= 1;
- exp1++;
- }
-
- /* lose extra precision */
- mant1 >>= 6;
-
- /* turn off hidden bit */
- mant1 &= ~HIDDEN;
-
- /* pack up and go home */
- fl1.l = PACK (sign, exp1, mant1);
-test_done:
- return (fl1.f);
-}
-
-/* subtract two floats */
-float
-__subsf3 (float a1, float a2)
-{
- union float_long fl1, fl2;
-
- fl1.f = a1;
- fl2.f = a2;
-
- /* check for zero args */
- if (!fl2.l)
- return (fl1.f);
- if (!fl1.l)
- return (-fl2.f);
-
- /* twiddle sign bit and add */
- fl2.l ^= SIGNBIT;
- return __addsf3 (a1, fl2.f);
-}
-
-/* compare two floats */
-long
-__cmpsf2 (float a1, float a2)
-{
- union float_long fl1, fl2;
-
- fl1.f = a1;
- fl2.f = a2;
-
- if (SIGN (fl1.l) && SIGN (fl2.l))
- {
- fl1.l ^= SIGNBIT;
- fl2.l ^= SIGNBIT;
- }
- if (fl1.l < fl2.l)
- return (-1);
- if (fl1.l > fl2.l)
- return (1);
- return (0);
-}
-
-/* multiply two floats */
-float
-__mulsf3 (float a1, float a2)
-{
- union float_long fl1, fl2;
- unsigned long result;
- int exp;
- int sign;
-
- fl1.f = a1;
- fl2.f = a2;
-
- if (!fl1.l || !fl2.l) {
- fl1.f = 0;
- goto test_done;
- }
-
- /* compute sign and exponent */
- sign = SIGN (fl1.l) ^ SIGN (fl2.l);
- exp = EXP (fl1.l) - EXCESS;
- exp += EXP (fl2.l);
-
- fl1.l = MANT (fl1.l);
- fl2.l = MANT (fl2.l);
-
- /* the multiply is done as one 16x16 multiply and two 16x8 multiples */
- result = (fl1.l >> 8) * (fl2.l >> 8);
- result += ((fl1.l & 0xFF) * (fl2.l >> 8)) >> 8;
- result += ((fl2.l & 0xFF) * (fl1.l >> 8)) >> 8;
-
- result >>= 2;
- if (result & 0x20000000)
- {
- /* round */
- result += 0x20;
- result >>= 6;
- }
- else
- {
- /* round */
- result += 0x10;
- result >>= 5;
- exp--;
- }
- if (result & (HIDDEN<<1)) {
- result >>= 1;
- exp++;
- }
-
- result &= ~HIDDEN;
-
- /* pack up and go home */
- fl1.l = PACK (sign, exp, result);
-test_done:
- return (fl1.f);
-}
-
-/* divide two floats */
-float
-__divsf3 (float a1, float a2)
-{
- union float_long fl1, fl2;
- int result;
- int mask;
- int exp, sign;
-
- fl1.f = a1;
- fl2.f = a2;
-
- /* subtract exponents */
- exp = EXP (fl1.l) - EXP (fl2.l) + EXCESS;
-
- /* compute sign */
- sign = SIGN (fl1.l) ^ SIGN (fl2.l);
-
- /* divide by zero??? */
- if (!fl2.l)
- /* return NaN or -NaN */
- return (sign ? 0xFFFFFFFF : 0x7FFFFFFF);
-
- /* numerator zero??? */
- if (!fl1.l)
- return (0);
-
- /* now get mantissas */
- fl1.l = MANT (fl1.l);
- fl2.l = MANT (fl2.l);
-
- /* this assures we have 25 bits of precision in the end */
- if (fl1.l < fl2.l)
- {
- fl1.l <<= 1;
- exp--;
- }
-
- /* now we perform repeated subtraction of fl2.l from fl1.l */
- mask = 0x1000000;
- result = 0;
- while (mask)
- {
- if (fl1.l >= fl2.l)
- {
- result |= mask;
- fl1.l -= fl2.l;
- }
- fl1.l <<= 1;
- mask >>= 1;
- }
-
- /* round */
- result += 1;
-
- /* normalize down */
- exp++;
- result >>= 1;
-
- result &= ~HIDDEN;
-
- /* pack up and go home */
- fl1.l = PACK (sign, exp, result);
- return (fl1.f);
-}
-
-/* convert int to double */
-double
-__floatsidf (long a1)
-{
- int 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 = -a1;
- }
-
- while (a1 < 0x1000000)
- {
- a1 <<= 4;
- exp -= 4;
- }
-
- while (a1 < 0x40000000)
- {
- a1 <<= 1;
- exp--;
- }
-
- /* pack up and go home */
- dl.l.upper = sign;
- dl.l.upper |= exp << 20;
- dl.l.upper |= (a1 >> 10) & ~HIDDEND;
- dl.l.lower = a1 << 22;
-
- return (dl.d);
-}
-
-double
-__floatdidf (long long a1)
-{
- int exp = 63 + EXCESSD;
- union double_long dl;
-
- dl.l.upper = dl.l.lower = 0;
- if (a1 == 0)
- return (dl.d);
-
- if (a1 < 0) {
- dl.l.upper = SIGNBIT;
- a1 = -a1;
- }
-
- while (a1 < (long long)1<<54) {
- a1 <<= 8;
- exp -= 8;
- }
- while (a1 < (long long)1<<62) {
- a1 <<= 1;
- exp -= 1;
- }
-
- /* pack up and go home */
- dl.ll |= (a1 >> 10) & ~HIDDEND_LL;
- dl.l.upper |= exp << 20;
-
- return (dl.d);
-}
-
-float
-__floatsisf (long a1)
-{
- (float)__floatsidf(a1);
-}
-
-float
-__floatdisf (long long a1)
-{
- (float)__floatdidf(a1);
-}
-
-/* negate a float */
-float
-__negsf2 (float a1)
-{
- union float_long fl1;
-
- fl1.f = a1;
- if (!fl1.l)
- return (0);
-
- fl1.l ^= SIGNBIT;
- return (fl1.f);
-}
-
-/* negate a double */
-double
-__negdf2 (double a1)
-{
- union double_long dl1;
-
- dl1.d = a1;
-
- if (!dl1.l.upper && !dl1.l.lower)
- return (dl1.d);
-
- dl1.l.upper ^= SIGNBIT;
- return (dl1.d);
-}
-
-/* convert float to double */
-double
-__extendsfdf2 (float a1)
-{
- union float_long fl1;
- union double_long dl;
- int exp;
-
- fl1.f = a1;
-
- if (!fl1.l)
- {
- dl.l.upper = dl.l.lower = 0;
- return (dl.d);
- }
-
- dl.l.upper = SIGN (fl1.l);
- exp = EXP (fl1.l) - EXCESS + EXCESSD;
- dl.l.upper |= exp << 20;
- dl.l.upper |= (MANT (fl1.l) & ~HIDDEN) >> 3;
- dl.l.lower = MANT (fl1.l) << 29;
-
- return (dl.d);
-}
-
-/* convert double to float */
-float
-__truncdfsf2 (double a1)
-{
- int exp;
- long mant;
- union float_long fl;
- union double_long dl1;
-
- dl1.d = a1;
-
- if (!dl1.l.upper && !dl1.l.lower)
- return (float)(0);
-
- exp = EXPD (dl1) - EXCESSD + EXCESS;
-
- /* shift double mantissa 6 bits so we can round */
- mant = MANTD (dl1) >> 6;
-
- /* now round and shift down */
- mant += 1;
- mant >>= 1;
-
- /* did the round overflow? */
- if (mant & 0xFE000000)
- {
- mant >>= 1;
- exp++;
- }
-
- mant &= ~HIDDEN;
-
- /* pack up and go home */
- fl.l = PACK (SIGND (dl1), exp, mant);
- return (fl.f);
-}
-
-/* compare two doubles */
-long
-__cmpdf2 (double a1, double a2)
-{
- union double_long dl1, dl2;
-
- dl1.d = a1;
- dl2.d = a2;
-
- if (SIGND (dl1) && SIGND (dl2))
- {
- dl1.l.upper ^= SIGNBIT;
- dl2.l.upper ^= SIGNBIT;
- }
- if (dl1.l.upper < dl2.l.upper)
- return (-1);
- if (dl1.l.upper > dl2.l.upper)
- return (1);
- if (dl1.l.lower < dl2.l.lower)
- return (-1);
- if (dl1.l.lower > dl2.l.lower)
- return (1);
- return (0);
-}
-
-/* convert double to int */
-long
-__fixdfsi (double a1)
-{
- union double_long dl1;
- int exp;
- 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 SIGND(dl1) ? (1<<31) : ((1ul<<31)-1);
-
- /* shift down until exp = 0 or l = 0 */
- if (exp < 0 && exp > -32 && l)
- l >>= -exp;
- else
- return (0);
-
- return (SIGND (dl1) ? -l : l);
-}
-
-/* convert double to int */
-long long
-__fixdfdi (double a1)
-{
- union double_long dl1;
- int exp;
- long long l;
-
- dl1.d = a1;
-
- if (!dl1.l.upper && !dl1.l.lower)
- return (0);
-
- exp = EXPD (dl1) - EXCESSD - 64;
- l = MANTD_LL(dl1);
-
- if (exp > 0) {
- l = (long long)1<<63;
- if (!SIGND(dl1))
- l--;
- return l;
- }
-
- /* shift down until exp = 0 or l = 0 */
- if (exp < 0 && exp > -64 && l)
- l >>= -exp;
- else
- return (0);
-
- return (SIGND (dl1) ? -l : l);
-}
-
-/* convert double to unsigned int */
-unsigned long
-__fixunsdfsi (double a1)
-{
- union double_long dl1;
- int exp;
- unsigned long l;
-
- dl1.d = a1;
-
- if (!dl1.l.upper && !dl1.l.lower)
- return (0);
-
- exp = EXPD (dl1) - EXCESSD - 32;
- l = (((((dl1.l.upper) & 0xFFFFF) | HIDDEND) << 11) | (dl1.l.lower >> 21));
-
- if (exp > 0)
- return (0xFFFFFFFFul); /* largest integer */
-
- /* shift down until exp = 0 or l = 0 */
- if (exp < 0 && exp > -32 && l)
- l >>= -exp;
- else
- return (0);
-
- return (l);
-}
-
-/* convert double to unsigned int */
-unsigned long long
-__fixunsdfdi (double a1)
-{
- union double_long dl1;
- int exp;
- unsigned long long l;
-
- dl1.d = a1;
-
- if (dl1.ll == 0)
- return (0);
-
- exp = EXPD (dl1) - EXCESSD - 64;
-
- l = dl1.ll;
-
- if (exp > 0)
- return (unsigned long long)-1;
-
- /* shift down until exp = 0 or l = 0 */
- if (exp < 0 && exp > -64 && l)
- l >>= -exp;
- else
- return (0);
-
- return (l);
-}
-
-/* addtwo doubles */
-double
-__adddf3 (double a1, double a2)
-{
- long long mant1, mant2;
- union double_long fl1, fl2;
- int exp1, exp2;
- int sign = 0;
-
- fl1.d = a1;
- fl2.d = a2;
-
- /* check for zero args */
- if (!fl2.ll)
- goto test_done;
- if (!fl1.ll) {
- fl1.d = fl2.d;
- goto test_done;
- }
-
- exp1 = EXPD(fl1);
- exp2 = EXPD(fl2);
-
- if (exp1 > exp2 + 54)
- goto test_done;
- if (exp2 > exp1 + 54) {
- fl1.d = fl2.d;
- goto test_done;
- }
-
- /* do everything in excess precision so's we can round later */
- mant1 = MANTD_LL(fl1) << 9;
- mant2 = MANTD_LL(fl2) << 9;
-
- if (SIGND(fl1))
- mant1 = -mant1;
- if (SIGND(fl2))
- mant2 = -mant2;
-
- if (exp1 > exp2)
- mant2 >>= exp1 - exp2;
- else {
- mant1 >>= exp2 - exp1;
- exp1 = exp2;
- }
- mant1 += mant2;
-
- if (mant1 < 0) {
- mant1 = -mant1;
- sign = SIGNBIT;
- } else if (!mant1) {
- fl1.d = 0;
- goto test_done;
- }
-
- /* normalize up */
- while (!(mant1 & ((long long)7<<61))) {
- mant1 <<= 1;
- exp1--;
- }
-
- /* normalize down? */
- if (mant1 & ((long long)3<<62)) {
- mant1 >>= 1;
- exp1++;
- }
-
- /* round to even */
- mant1 += (mant1 & (1<<9)) ? (1<<8) : ((1<<8)-1);
-
- /* normalize down? */
- if (mant1 & ((long long)3<<62)) {
- mant1 >>= 1;
- exp1++;
- }
-
- /* lose extra precision */
- mant1 >>= 9;
-
- /* turn off hidden bit */
- mant1 &= ~HIDDEND_LL;
-
- /* pack up and go home */
- fl1.ll = PACKD_LL(sign,exp1,mant1);
-
-test_done:
- return (fl1.d);
-}
-
-/* subtract two doubles */
-double
-__subdf3 (double a1, double a2)
-{
- union double_long fl1, fl2;
-
- fl1.d = a1;
- fl2.d = a2;
-
- /* check for zero args */
- if (!fl2.ll)
- return (fl1.d);
- /* twiddle sign bit and add */
- fl2.l.upper ^= SIGNBIT;
- if (!fl1.ll)
- return (fl2.d);
- return __adddf3 (a1, fl2.d);
-}
-
-/* multiply two doubles */
-double
-__muldf3 (double a1, double a2)
-{
- union double_long fl1, fl2;
- unsigned long long result;
- int exp;
- int sign;
-
- fl1.d = a1;
- fl2.d = a2;
-
- if (!fl1.ll || !fl2.ll) {
- fl1.d = 0;
- goto test_done;
- }
-
- /* compute sign and exponent */
- sign = SIGND(fl1) ^ SIGND(fl2);
- exp = EXPD(fl1) - EXCESSD;
- exp += EXPD(fl2);
-
- fl1.ll = MANTD_LL(fl1);
- fl2.ll = MANTD_LL(fl2);
-
- /* the multiply is done as one 31x31 multiply and two 31x21 multiples */
- result = (fl1.ll >> 21) * (fl2.ll >> 21);
- result += ((fl1.ll & 0x1FFFFF) * (fl2.ll >> 21)) >> 21;
- result += ((fl2.ll & 0x1FFFFF) * (fl1.ll >> 21)) >> 21;
-
- result >>= 2;
- if (result & ((long long)1<<61)) {
- /* round */
- result += 1<<8;
- result >>= 9;
- } else {
- /* round */
- result += 1<<7;
- result >>= 8;
- exp--;
- }
- if (result & (HIDDEND_LL<<1)) {
- result >>= 1;
- exp++;
- }
-
- result &= ~HIDDEND_LL;
-
- /* pack up and go home */
- fl1.ll = PACKD_LL(sign,exp,result);
-test_done:
- return (fl1.d);
-}
-
-/* divide two doubles */
-double
-__divdf3 (double a1, double a2)
-{
- union double_long fl1, fl2;
- long long mask,result;
- int exp, sign;
-
- fl1.d = a1;
- fl2.d = a2;
-
- /* subtract exponents */
- exp = EXPD(fl1) - EXPD(fl2) + EXCESSD;
-
- /* compute sign */
- sign = SIGND(fl1) ^ SIGND(fl2);
-
- /* numerator zero??? */
- if (fl1.ll == 0) {
- /* divide by zero??? */
- if (fl2.ll == 0)
- fl1.ll = ((unsigned long long)1<<63)-1; /* NaN */
- else
- fl1.ll = 0;
- goto test_done;
- }
-
- /* return +Inf or -Inf */
- if (fl2.ll == 0) {
- fl1.ll = PACKD_LL(SIGND(fl1),2047,0);
- goto test_done;
- }
-
-
- /* now get mantissas */
- fl1.ll = MANTD_LL(fl1);
- fl2.ll = MANTD_LL(fl2);
-
- /* this assures we have 54 bits of precision in the end */
- if (fl1.ll < fl2.ll) {
- fl1.ll <<= 1;
- exp--;
- }
-
- /* now we perform repeated subtraction of fl2.ll from fl1.ll */
- mask = (long long)1<<53;
- result = 0;
- while (mask) {
- if (fl1.ll >= fl2.ll)
- {
- result |= mask;
- fl1.ll -= fl2.ll;
- }
- fl1.ll <<= 1;
- mask >>= 1;
- }
-
- /* round */
- result += 1;
-
- /* normalize down */
- exp++;
- result >>= 1;
-
- result &= ~HIDDEND_LL;
-
- /* pack up and go home */
- fl1.ll = PACKD_LL(sign, exp, result);
-
-test_done:
- return (fl1.d);
-}
-
-int
-__gtdf2 (double a1, double a2)
-{
- return __cmpdf2 ((float) a1, (float) a2) > 0;
-}
-
-int
-__gedf2 (double a1, double a2)
-{
- return (__cmpdf2 ((float) a1, (float) a2) >= 0) - 1;
-}
-
-int
-__ltdf2 (double a1, double a2)
-{
- return - (__cmpdf2 ((float) a1, (float) a2) < 0);
-}
-
-int
-__ledf2 (double a1, double a2)
-{
- return __cmpdf2 ((float) a1, (float) a2) > 0;
-}
-
-int
-__eqdf2 (double a1, double a2)
-{
- return *(long long *) &a1 == *(long long *) &a2;
-}
-
-int
-__nedf2 (double a1, double a2)
-{
- return *(long long *) &a1 != *(long long *) &a2;
-}
projects / msp430-gcc.git / blobdiff