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author | das <das@FreeBSD.org> | 2008-09-03 05:17:02 +0000 |
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committer | das <das@FreeBSD.org> | 2008-09-03 05:17:02 +0000 |
commit | 785a4b4a47b63f20f447a0151f2cf11d1e5d4482 (patch) | |
tree | b69321c7698697d9b90df7930be5cd5a7d1f54e4 /contrib/gdtoa/strtod.c | |
parent | 5bc737f35262327ca86ef96a7cbc6680c8eeb2ea (diff) | |
download | FreeBSD-src-785a4b4a47b63f20f447a0151f2cf11d1e5d4482.zip FreeBSD-src-785a4b4a47b63f20f447a0151f2cf11d1e5d4482.tar.gz |
Flatten vendor/gdtoa/*.
Diffstat (limited to 'contrib/gdtoa/strtod.c')
-rw-r--r-- | contrib/gdtoa/strtod.c | 982 |
1 files changed, 0 insertions, 982 deletions
diff --git a/contrib/gdtoa/strtod.c b/contrib/gdtoa/strtod.c deleted file mode 100644 index 66a3baa..0000000 --- a/contrib/gdtoa/strtod.c +++ /dev/null @@ -1,982 +0,0 @@ -/**************************************************************** - -The author of this software is David M. Gay. - -Copyright (C) 1998-2001 by Lucent Technologies -All Rights Reserved - -Permission to use, copy, modify, and distribute this software and -its documentation for any purpose and without fee is hereby -granted, provided that the above copyright notice appear in all -copies and that both that the copyright notice and this -permission notice and warranty disclaimer appear in supporting -documentation, and that the name of Lucent or any of its entities -not be used in advertising or publicity pertaining to -distribution of the software without specific, written prior -permission. - -LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, -INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. -IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY -SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES -WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER -IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, -ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF -THIS SOFTWARE. - -****************************************************************/ - -/* Please send bug reports to David M. Gay (dmg at acm dot org, - * with " at " changed at "@" and " dot " changed to "."). */ - -#include "gdtoaimp.h" -#ifndef NO_FENV_H -#include <fenv.h> -#endif - -#ifdef USE_LOCALE -#include "locale.h" -#endif - -#ifdef IEEE_Arith -#ifndef NO_IEEE_Scale -#define Avoid_Underflow -#undef tinytens -/* The factor of 2^53 in tinytens[4] helps us avoid setting the underflow */ -/* flag unnecessarily. It leads to a song and dance at the end of strtod. */ -static CONST double tinytens[] = { 1e-16, 1e-32, 1e-64, 1e-128, - 9007199254740992.e-256 - }; -#endif -#endif - -#ifdef Honor_FLT_ROUNDS -#define Rounding rounding -#undef Check_FLT_ROUNDS -#define Check_FLT_ROUNDS -#else -#define Rounding Flt_Rounds -#endif - - double -strtod -#ifdef KR_headers - (s00, se) CONST char *s00; char **se; -#else - (CONST char *s00, char **se) -#endif -{ -#ifdef Avoid_Underflow - int scale; -#endif - int bb2, bb5, bbe, bd2, bd5, bbbits, bs2, c, decpt, dsign, - e, e1, esign, i, j, k, nd, nd0, nf, nz, nz0, sign; - CONST char *s, *s0, *s1; - double aadj, aadj1, adj, rv, rv0; - Long L; - ULong y, z; - Bigint *bb, *bb1, *bd, *bd0, *bs, *delta; -#ifdef SET_INEXACT - int inexact, oldinexact; -#endif -#ifdef Honor_FLT_ROUNDS - int rounding; -#endif - - sign = nz0 = nz = decpt = 0; - dval(rv) = 0.; - for(s = s00;;s++) switch(*s) { - case '-': - sign = 1; - /* no break */ - case '+': - if (*++s) - goto break2; - /* no break */ - case 0: - goto ret0; - case '\t': - case '\n': - case '\v': - case '\f': - case '\r': - case ' ': - continue; - default: - goto break2; - } - break2: - if (*s == '0') { -#ifndef NO_HEX_FP - { - static FPI fpi = { 53, 1-1023-53+1, 2046-1023-53+1, 1, SI }; - Long exp; - ULong bits[2]; - switch(s[1]) { - case 'x': - case 'X': - { -#if defined(FE_DOWNWARD) && defined(FE_TONEAREST) && defined(FE_TOWARDZERO) && defined(FE_UPWARD) - FPI fpi1 = fpi; - switch(fegetround()) { - case FE_TOWARDZERO: fpi1.rounding = 0; break; - case FE_UPWARD: fpi1.rounding = 2; break; - case FE_DOWNWARD: fpi1.rounding = 3; - } -#else -#define fpi1 fpi -#endif - switch((i = gethex(&s, &fpi1, &exp, &bb, sign)) & STRTOG_Retmask) { - case STRTOG_NoNumber: - s = s00; - sign = 0; - case STRTOG_Zero: - break; - default: - if (bb) { - copybits(bits, fpi.nbits, bb); - Bfree(bb); - } - ULtod(((U*)&rv)->L, bits, exp, i); - }} - goto ret; - } - } -#endif - nz0 = 1; - while(*++s == '0') ; - if (!*s) - goto ret; - } - s0 = s; - y = z = 0; - for(nd = nf = 0; (c = *s) >= '0' && c <= '9'; nd++, s++) - if (nd < 9) - y = 10*y + c - '0'; - else if (nd < 16) - z = 10*z + c - '0'; - nd0 = nd; -#ifdef USE_LOCALE - if (c == *localeconv()->decimal_point) -#else - if (c == '.') -#endif - { - decpt = 1; - c = *++s; - if (!nd) { - for(; c == '0'; c = *++s) - nz++; - if (c > '0' && c <= '9') { - s0 = s; - nf += nz; - nz = 0; - goto have_dig; - } - goto dig_done; - } - for(; c >= '0' && c <= '9'; c = *++s) { - have_dig: - nz++; - if (c -= '0') { - nf += nz; - for(i = 1; i < nz; i++) - if (nd++ < 9) - y *= 10; - else if (nd <= DBL_DIG + 1) - z *= 10; - if (nd++ < 9) - y = 10*y + c; - else if (nd <= DBL_DIG + 1) - z = 10*z + c; - nz = 0; - } - } - } - dig_done: - e = 0; - if (c == 'e' || c == 'E') { - if (!nd && !nz && !nz0) { - goto ret0; - } - s00 = s; - esign = 0; - switch(c = *++s) { - case '-': - esign = 1; - case '+': - c = *++s; - } - if (c >= '0' && c <= '9') { - while(c == '0') - c = *++s; - if (c > '0' && c <= '9') { - L = c - '0'; - s1 = s; - while((c = *++s) >= '0' && c <= '9') - L = 10*L + c - '0'; - if (s - s1 > 8 || L > 19999) - /* Avoid confusion from exponents - * so large that e might overflow. - */ - e = 19999; /* safe for 16 bit ints */ - else - e = (int)L; - if (esign) - e = -e; - } - else - e = 0; - } - else - s = s00; - } - if (!nd) { - if (!nz && !nz0) { -#ifdef INFNAN_CHECK - /* Check for Nan and Infinity */ - ULong bits[2]; - static FPI fpinan = /* only 52 explicit bits */ - { 52, 1-1023-53+1, 2046-1023-53+1, 1, SI }; - if (!decpt) - switch(c) { - case 'i': - case 'I': - if (match(&s,"nf")) { - --s; - if (!match(&s,"inity")) - ++s; - word0(rv) = 0x7ff00000; - word1(rv) = 0; - goto ret; - } - break; - case 'n': - case 'N': - if (match(&s, "an")) { -#ifndef No_Hex_NaN - if (*s == '(' /*)*/ - && hexnan(&s, &fpinan, bits) - == STRTOG_NaNbits) { - word0(rv) = 0x7ff00000 | bits[1]; - word1(rv) = bits[0]; - } - else { -#endif - word0(rv) = NAN_WORD0; - word1(rv) = NAN_WORD1; -#ifndef No_Hex_NaN - } -#endif - goto ret; - } - } -#endif /* INFNAN_CHECK */ - ret0: - s = s00; - sign = 0; - } - goto ret; - } - e1 = e -= nf; - - /* Now we have nd0 digits, starting at s0, followed by a - * decimal point, followed by nd-nd0 digits. The number we're - * after is the integer represented by those digits times - * 10**e */ - - if (!nd0) - nd0 = nd; - k = nd < DBL_DIG + 1 ? nd : DBL_DIG + 1; - dval(rv) = y; - if (k > 9) { -#ifdef SET_INEXACT - if (k > DBL_DIG) - oldinexact = get_inexact(); -#endif - dval(rv) = tens[k - 9] * dval(rv) + z; - } - bd0 = 0; - if (nd <= DBL_DIG -#ifndef RND_PRODQUOT -#ifndef Honor_FLT_ROUNDS - && Flt_Rounds == 1 -#endif -#endif - ) { - if (!e) - goto ret; - if (e > 0) { - if (e <= Ten_pmax) { -#ifdef VAX - goto vax_ovfl_check; -#else -#ifdef Honor_FLT_ROUNDS - /* round correctly FLT_ROUNDS = 2 or 3 */ - if (sign) { - rv = -rv; - sign = 0; - } -#endif - /* rv = */ rounded_product(dval(rv), tens[e]); - goto ret; -#endif - } - i = DBL_DIG - nd; - if (e <= Ten_pmax + i) { - /* A fancier test would sometimes let us do - * this for larger i values. - */ -#ifdef Honor_FLT_ROUNDS - /* round correctly FLT_ROUNDS = 2 or 3 */ - if (sign) { - rv = -rv; - sign = 0; - } -#endif - e -= i; - dval(rv) *= tens[i]; -#ifdef VAX - /* VAX exponent range is so narrow we must - * worry about overflow here... - */ - vax_ovfl_check: - word0(rv) -= P*Exp_msk1; - /* rv = */ rounded_product(dval(rv), tens[e]); - if ((word0(rv) & Exp_mask) - > Exp_msk1*(DBL_MAX_EXP+Bias-1-P)) - goto ovfl; - word0(rv) += P*Exp_msk1; -#else - /* rv = */ rounded_product(dval(rv), tens[e]); -#endif - goto ret; - } - } -#ifndef Inaccurate_Divide - else if (e >= -Ten_pmax) { -#ifdef Honor_FLT_ROUNDS - /* round correctly FLT_ROUNDS = 2 or 3 */ - if (sign) { - rv = -rv; - sign = 0; - } -#endif - /* rv = */ rounded_quotient(dval(rv), tens[-e]); - goto ret; - } -#endif - } - e1 += nd - k; - -#ifdef IEEE_Arith -#ifdef SET_INEXACT - inexact = 1; - if (k <= DBL_DIG) - oldinexact = get_inexact(); -#endif -#ifdef Avoid_Underflow - scale = 0; -#endif -#ifdef Honor_FLT_ROUNDS - if ((rounding = Flt_Rounds) >= 2) { - if (sign) - rounding = rounding == 2 ? 0 : 2; - else - if (rounding != 2) - rounding = 0; - } -#endif -#endif /*IEEE_Arith*/ - - /* Get starting approximation = rv * 10**e1 */ - - if (e1 > 0) { - if ( (i = e1 & 15) !=0) - dval(rv) *= tens[i]; - if (e1 &= ~15) { - if (e1 > DBL_MAX_10_EXP) { - ovfl: -#ifndef NO_ERRNO - errno = ERANGE; -#endif - /* Can't trust HUGE_VAL */ -#ifdef IEEE_Arith -#ifdef Honor_FLT_ROUNDS - switch(rounding) { - case 0: /* toward 0 */ - case 3: /* toward -infinity */ - word0(rv) = Big0; - word1(rv) = Big1; - break; - default: - word0(rv) = Exp_mask; - word1(rv) = 0; - } -#else /*Honor_FLT_ROUNDS*/ - word0(rv) = Exp_mask; - word1(rv) = 0; -#endif /*Honor_FLT_ROUNDS*/ -#ifdef SET_INEXACT - /* set overflow bit */ - dval(rv0) = 1e300; - dval(rv0) *= dval(rv0); -#endif -#else /*IEEE_Arith*/ - word0(rv) = Big0; - word1(rv) = Big1; -#endif /*IEEE_Arith*/ - if (bd0) - goto retfree; - goto ret; - } - e1 >>= 4; - for(j = 0; e1 > 1; j++, e1 >>= 1) - if (e1 & 1) - dval(rv) *= bigtens[j]; - /* The last multiplication could overflow. */ - word0(rv) -= P*Exp_msk1; - dval(rv) *= bigtens[j]; - if ((z = word0(rv) & Exp_mask) - > Exp_msk1*(DBL_MAX_EXP+Bias-P)) - goto ovfl; - if (z > Exp_msk1*(DBL_MAX_EXP+Bias-1-P)) { - /* set to largest number */ - /* (Can't trust DBL_MAX) */ - word0(rv) = Big0; - word1(rv) = Big1; - } - else - word0(rv) += P*Exp_msk1; - } - } - else if (e1 < 0) { - e1 = -e1; - if ( (i = e1 & 15) !=0) - dval(rv) /= tens[i]; - if (e1 >>= 4) { - if (e1 >= 1 << n_bigtens) - goto undfl; -#ifdef Avoid_Underflow - if (e1 & Scale_Bit) - scale = 2*P; - for(j = 0; e1 > 0; j++, e1 >>= 1) - if (e1 & 1) - dval(rv) *= tinytens[j]; - if (scale && (j = 2*P + 1 - ((word0(rv) & Exp_mask) - >> Exp_shift)) > 0) { - /* scaled rv is denormal; zap j low bits */ - if (j >= 32) { - word1(rv) = 0; - if (j >= 53) - word0(rv) = (P+2)*Exp_msk1; - else - word0(rv) &= 0xffffffff << j-32; - } - else - word1(rv) &= 0xffffffff << j; - } -#else - for(j = 0; e1 > 1; j++, e1 >>= 1) - if (e1 & 1) - dval(rv) *= tinytens[j]; - /* The last multiplication could underflow. */ - dval(rv0) = dval(rv); - dval(rv) *= tinytens[j]; - if (!dval(rv)) { - dval(rv) = 2.*dval(rv0); - dval(rv) *= tinytens[j]; -#endif - if (!dval(rv)) { - undfl: - dval(rv) = 0.; -#ifndef NO_ERRNO - errno = ERANGE; -#endif - if (bd0) - goto retfree; - goto ret; - } -#ifndef Avoid_Underflow - word0(rv) = Tiny0; - word1(rv) = Tiny1; - /* The refinement below will clean - * this approximation up. - */ - } -#endif - } - } - - /* Now the hard part -- adjusting rv to the correct value.*/ - - /* Put digits into bd: true value = bd * 10^e */ - - bd0 = s2b(s0, nd0, nd, y); - - for(;;) { - bd = Balloc(bd0->k); - Bcopy(bd, bd0); - bb = d2b(dval(rv), &bbe, &bbbits); /* rv = bb * 2^bbe */ - bs = i2b(1); - - if (e >= 0) { - bb2 = bb5 = 0; - bd2 = bd5 = e; - } - else { - bb2 = bb5 = -e; - bd2 = bd5 = 0; - } - if (bbe >= 0) - bb2 += bbe; - else - bd2 -= bbe; - bs2 = bb2; -#ifdef Honor_FLT_ROUNDS - if (rounding != 1) - bs2++; -#endif -#ifdef Avoid_Underflow - j = bbe - scale; - i = j + bbbits - 1; /* logb(rv) */ - if (i < Emin) /* denormal */ - j += P - Emin; - else - j = P + 1 - bbbits; -#else /*Avoid_Underflow*/ -#ifdef Sudden_Underflow -#ifdef IBM - j = 1 + 4*P - 3 - bbbits + ((bbe + bbbits - 1) & 3); -#else - j = P + 1 - bbbits; -#endif -#else /*Sudden_Underflow*/ - j = bbe; - i = j + bbbits - 1; /* logb(rv) */ - if (i < Emin) /* denormal */ - j += P - Emin; - else - j = P + 1 - bbbits; -#endif /*Sudden_Underflow*/ -#endif /*Avoid_Underflow*/ - bb2 += j; - bd2 += j; -#ifdef Avoid_Underflow - bd2 += scale; -#endif - i = bb2 < bd2 ? bb2 : bd2; - if (i > bs2) - i = bs2; - if (i > 0) { - bb2 -= i; - bd2 -= i; - bs2 -= i; - } - if (bb5 > 0) { - bs = pow5mult(bs, bb5); - bb1 = mult(bs, bb); - Bfree(bb); - bb = bb1; - } - if (bb2 > 0) - bb = lshift(bb, bb2); - if (bd5 > 0) - bd = pow5mult(bd, bd5); - if (bd2 > 0) - bd = lshift(bd, bd2); - if (bs2 > 0) - bs = lshift(bs, bs2); - delta = diff(bb, bd); - dsign = delta->sign; - delta->sign = 0; - i = cmp(delta, bs); -#ifdef Honor_FLT_ROUNDS - if (rounding != 1) { - if (i < 0) { - /* Error is less than an ulp */ - if (!delta->x[0] && delta->wds <= 1) { - /* exact */ -#ifdef SET_INEXACT - inexact = 0; -#endif - break; - } - if (rounding) { - if (dsign) { - adj = 1.; - goto apply_adj; - } - } - else if (!dsign) { - adj = -1.; - if (!word1(rv) - && !(word0(rv) & Frac_mask)) { - y = word0(rv) & Exp_mask; -#ifdef Avoid_Underflow - if (!scale || y > 2*P*Exp_msk1) -#else - if (y) -#endif - { - delta = lshift(delta,Log2P); - if (cmp(delta, bs) <= 0) - adj = -0.5; - } - } - apply_adj: -#ifdef Avoid_Underflow - if (scale && (y = word0(rv) & Exp_mask) - <= 2*P*Exp_msk1) - word0(adj) += (2*P+1)*Exp_msk1 - y; -#else -#ifdef Sudden_Underflow - if ((word0(rv) & Exp_mask) <= - P*Exp_msk1) { - word0(rv) += P*Exp_msk1; - dval(rv) += adj*ulp(dval(rv)); - word0(rv) -= P*Exp_msk1; - } - else -#endif /*Sudden_Underflow*/ -#endif /*Avoid_Underflow*/ - dval(rv) += adj*ulp(dval(rv)); - } - break; - } - adj = ratio(delta, bs); - if (adj < 1.) - adj = 1.; - if (adj <= 0x7ffffffe) { - /* adj = rounding ? ceil(adj) : floor(adj); */ - y = adj; - if (y != adj) { - if (!((rounding>>1) ^ dsign)) - y++; - adj = y; - } - } -#ifdef Avoid_Underflow - if (scale && (y = word0(rv) & Exp_mask) <= 2*P*Exp_msk1) - word0(adj) += (2*P+1)*Exp_msk1 - y; -#else -#ifdef Sudden_Underflow - if ((word0(rv) & Exp_mask) <= P*Exp_msk1) { - word0(rv) += P*Exp_msk1; - adj *= ulp(dval(rv)); - if (dsign) - dval(rv) += adj; - else - dval(rv) -= adj; - word0(rv) -= P*Exp_msk1; - goto cont; - } -#endif /*Sudden_Underflow*/ -#endif /*Avoid_Underflow*/ - adj *= ulp(dval(rv)); - if (dsign) - dval(rv) += adj; - else - dval(rv) -= adj; - goto cont; - } -#endif /*Honor_FLT_ROUNDS*/ - - if (i < 0) { - /* Error is less than half an ulp -- check for - * special case of mantissa a power of two. - */ - if (dsign || word1(rv) || word0(rv) & Bndry_mask -#ifdef IEEE_Arith -#ifdef Avoid_Underflow - || (word0(rv) & Exp_mask) <= (2*P+1)*Exp_msk1 -#else - || (word0(rv) & Exp_mask) <= Exp_msk1 -#endif -#endif - ) { -#ifdef SET_INEXACT - if (!delta->x[0] && delta->wds <= 1) - inexact = 0; -#endif - break; - } - if (!delta->x[0] && delta->wds <= 1) { - /* exact result */ -#ifdef SET_INEXACT - inexact = 0; -#endif - break; - } - delta = lshift(delta,Log2P); - if (cmp(delta, bs) > 0) - goto drop_down; - break; - } - if (i == 0) { - /* exactly half-way between */ - if (dsign) { - if ((word0(rv) & Bndry_mask1) == Bndry_mask1 - && word1(rv) == ( -#ifdef Avoid_Underflow - (scale && (y = word0(rv) & Exp_mask) <= 2*P*Exp_msk1) - ? (0xffffffff & (0xffffffff << (2*P+1-(y>>Exp_shift)))) : -#endif - 0xffffffff)) { - /*boundary case -- increment exponent*/ - word0(rv) = (word0(rv) & Exp_mask) - + Exp_msk1 -#ifdef IBM - | Exp_msk1 >> 4 -#endif - ; - word1(rv) = 0; -#ifdef Avoid_Underflow - dsign = 0; -#endif - break; - } - } - else if (!(word0(rv) & Bndry_mask) && !word1(rv)) { - drop_down: - /* boundary case -- decrement exponent */ -#ifdef Sudden_Underflow /*{{*/ - L = word0(rv) & Exp_mask; -#ifdef IBM - if (L < Exp_msk1) -#else -#ifdef Avoid_Underflow - if (L <= (scale ? (2*P+1)*Exp_msk1 : Exp_msk1)) -#else - if (L <= Exp_msk1) -#endif /*Avoid_Underflow*/ -#endif /*IBM*/ - goto undfl; - L -= Exp_msk1; -#else /*Sudden_Underflow}{*/ -#ifdef Avoid_Underflow - if (scale) { - L = word0(rv) & Exp_mask; - if (L <= (2*P+1)*Exp_msk1) { - if (L > (P+2)*Exp_msk1) - /* round even ==> */ - /* accept rv */ - break; - /* rv = smallest denormal */ - goto undfl; - } - } -#endif /*Avoid_Underflow*/ - L = (word0(rv) & Exp_mask) - Exp_msk1; -#endif /*Sudden_Underflow}*/ - word0(rv) = L | Bndry_mask1; - word1(rv) = 0xffffffff; -#ifdef IBM - goto cont; -#else - break; -#endif - } -#ifndef ROUND_BIASED - if (!(word1(rv) & LSB)) - break; -#endif - if (dsign) - dval(rv) += ulp(dval(rv)); -#ifndef ROUND_BIASED - else { - dval(rv) -= ulp(dval(rv)); -#ifndef Sudden_Underflow - if (!dval(rv)) - goto undfl; -#endif - } -#ifdef Avoid_Underflow - dsign = 1 - dsign; -#endif -#endif - break; - } - if ((aadj = ratio(delta, bs)) <= 2.) { - if (dsign) - aadj = aadj1 = 1.; - else if (word1(rv) || word0(rv) & Bndry_mask) { -#ifndef Sudden_Underflow - if (word1(rv) == Tiny1 && !word0(rv)) - goto undfl; -#endif - aadj = 1.; - aadj1 = -1.; - } - else { - /* special case -- power of FLT_RADIX to be */ - /* rounded down... */ - - if (aadj < 2./FLT_RADIX) - aadj = 1./FLT_RADIX; - else - aadj *= 0.5; - aadj1 = -aadj; - } - } - else { - aadj *= 0.5; - aadj1 = dsign ? aadj : -aadj; -#ifdef Check_FLT_ROUNDS - switch(Rounding) { - case 2: /* towards +infinity */ - aadj1 -= 0.5; - break; - case 0: /* towards 0 */ - case 3: /* towards -infinity */ - aadj1 += 0.5; - } -#else - if (Flt_Rounds == 0) - aadj1 += 0.5; -#endif /*Check_FLT_ROUNDS*/ - } - y = word0(rv) & Exp_mask; - - /* Check for overflow */ - - if (y == Exp_msk1*(DBL_MAX_EXP+Bias-1)) { - dval(rv0) = dval(rv); - word0(rv) -= P*Exp_msk1; - adj = aadj1 * ulp(dval(rv)); - dval(rv) += adj; - if ((word0(rv) & Exp_mask) >= - Exp_msk1*(DBL_MAX_EXP+Bias-P)) { - if (word0(rv0) == Big0 && word1(rv0) == Big1) - goto ovfl; - word0(rv) = Big0; - word1(rv) = Big1; - goto cont; - } - else - word0(rv) += P*Exp_msk1; - } - else { -#ifdef Avoid_Underflow - if (scale && y <= 2*P*Exp_msk1) { - if (aadj <= 0x7fffffff) { - if ((z = aadj) <= 0) - z = 1; - aadj = z; - aadj1 = dsign ? aadj : -aadj; - } - word0(aadj1) += (2*P+1)*Exp_msk1 - y; - } - adj = aadj1 * ulp(dval(rv)); - dval(rv) += adj; -#else -#ifdef Sudden_Underflow - if ((word0(rv) & Exp_mask) <= P*Exp_msk1) { - dval(rv0) = dval(rv); - word0(rv) += P*Exp_msk1; - adj = aadj1 * ulp(dval(rv)); - dval(rv) += adj; -#ifdef IBM - if ((word0(rv) & Exp_mask) < P*Exp_msk1) -#else - if ((word0(rv) & Exp_mask) <= P*Exp_msk1) -#endif - { - if (word0(rv0) == Tiny0 - && word1(rv0) == Tiny1) - goto undfl; - word0(rv) = Tiny0; - word1(rv) = Tiny1; - goto cont; - } - else - word0(rv) -= P*Exp_msk1; - } - else { - adj = aadj1 * ulp(dval(rv)); - dval(rv) += adj; - } -#else /*Sudden_Underflow*/ - /* Compute adj so that the IEEE rounding rules will - * correctly round rv + adj in some half-way cases. - * If rv * ulp(rv) is denormalized (i.e., - * y <= (P-1)*Exp_msk1), we must adjust aadj to avoid - * trouble from bits lost to denormalization; - * example: 1.2e-307 . - */ - if (y <= (P-1)*Exp_msk1 && aadj > 1.) { - aadj1 = (double)(int)(aadj + 0.5); - if (!dsign) - aadj1 = -aadj1; - } - adj = aadj1 * ulp(dval(rv)); - dval(rv) += adj; -#endif /*Sudden_Underflow*/ -#endif /*Avoid_Underflow*/ - } - z = word0(rv) & Exp_mask; -#ifndef SET_INEXACT -#ifdef Avoid_Underflow - if (!scale) -#endif - if (y == z) { - /* Can we stop now? */ - L = (Long)aadj; - aadj -= L; - /* The tolerances below are conservative. */ - if (dsign || word1(rv) || word0(rv) & Bndry_mask) { - if (aadj < .4999999 || aadj > .5000001) - break; - } - else if (aadj < .4999999/FLT_RADIX) - break; - } -#endif - cont: - Bfree(bb); - Bfree(bd); - Bfree(bs); - Bfree(delta); - } -#ifdef SET_INEXACT - if (inexact) { - if (!oldinexact) { - word0(rv0) = Exp_1 + (70 << Exp_shift); - word1(rv0) = 0; - dval(rv0) += 1.; - } - } - else if (!oldinexact) - clear_inexact(); -#endif -#ifdef Avoid_Underflow - if (scale) { - word0(rv0) = Exp_1 - 2*P*Exp_msk1; - word1(rv0) = 0; - dval(rv) *= dval(rv0); -#ifndef NO_ERRNO - /* try to avoid the bug of testing an 8087 register value */ - if (word0(rv) == 0 && word1(rv) == 0) - errno = ERANGE; -#endif - } -#endif /* Avoid_Underflow */ -#ifdef SET_INEXACT - if (inexact && !(word0(rv) & Exp_mask)) { - /* set underflow bit */ - dval(rv0) = 1e-300; - dval(rv0) *= dval(rv0); - } -#endif - retfree: - Bfree(bb); - Bfree(bd); - Bfree(bs); - Bfree(bd0); - Bfree(delta); - ret: - if (se) - *se = (char *)s; - return sign ? -dval(rv) : dval(rv); - } - |