/* $NetBSD: strtodg.c,v 1.5.14.1 2008/04/08 21:10:55 jdc Exp $ */ /**************************************************************** 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 #include "gdtoaimp.h" #ifdef USE_LOCALE #include "locale.h" #endif #if defined(_MSC_VER) // Disable warnings about assignment within conditional expressions. #pragma warning ( disable : 4706 ) #endif static CONST int fivesbits[] = { 0, 3, 5, 7, 10, 12, 14, 17, 19, 21, 24, 26, 28, 31, 33, 35, 38, 40, 42, 45, 47, 49, 52 #ifdef VAX , 54, 56 #endif }; Bigint * #ifdef KR_headers increment(b) Bigint *b; #else increment(Bigint *b) #endif { ULong *x, *xe; Bigint *b1; #ifdef Pack_16 ULong carry = 1, y; #endif x = b->x; xe = x + b->wds; #ifdef Pack_32 do { if (*x < (ULong)0xffffffffL) { ++*x; return b; } *x++ = 0; } while(x < xe); #else do { y = *x + carry; carry = y >> 16; *x++ = y & 0xffff; if (!carry) return b; } while(x < xe); if (carry) #endif { if (b->wds >= b->maxwds) { b1 = Balloc(b->k+1); if (b1 == NULL) return NULL; Bcopy(b1,b); Bfree(b); b = b1; } b->x[b->wds++] = 1; } return b; } int #ifdef KR_headers decrement(b) Bigint *b; #else decrement(Bigint *b) #endif { ULong *x, *xe; #ifdef Pack_16 ULong borrow = 1, y; #endif x = b->x; xe = x + b->wds; #ifdef Pack_32 do { if (*x) { --*x; break; } *x++ = 0xffffffffUL; } while(x < xe); #else do { y = *x - borrow; borrow = (y & 0x10000) >> 16; *x++ = y & 0xffff; } while(borrow && x < xe); #endif return STRTOG_Inexlo; } static int #ifdef KR_headers all_on(b, n) CONST Bigint *b; int n; #else all_on(CONST Bigint *b, int n) #endif { CONST ULong *x, *xe; x = b->x; xe = x + ((unsigned int)n >> kshift); while(x < xe) if ((*x++ & ALL_ON) != ALL_ON) return 0; if (n &= kmask) return ((*x | (ALL_ON << n)) & ALL_ON) == ALL_ON; return 1; } Bigint * #ifdef KR_headers set_ones(b, n) Bigint *b; int n; #else set_ones(Bigint *b, int n) #endif { int k; ULong *x, *xe; k = (unsigned int)(n + ((1 << kshift) - 1)) >> kshift; if (b->k < k) { Bfree(b); b = Balloc(k); if (b == NULL) return NULL; } k = (unsigned int)n >> kshift; if (n &= kmask) k++; b->wds = k; x = b->x; xe = x + k; while(x < xe) *x++ = ALL_ON; if (n) x[-1] >>= ULbits - n; return b; } static int rvOK #ifdef KR_headers (d, fpi, expt, bits, exact, rd, irv) double d; CONST FPI *fpi; Long *expt; ULong *bits; int exact, rd, *irv; #else (double d, CONST FPI *fpi, Long *expt, ULong *bits, int exact, int rd, int *irv) #endif { Bigint *b; ULong carry, inex, lostbits; int bdif, e, j, k, k1, nb, rv; carry = rv = 0; b = d2b(d, &e, &bdif); bdif -= nb = fpi->nbits; e += bdif; if (bdif <= 0) { if (exact) goto trunc; goto ret; } if (P == nb) { if ( #ifndef IMPRECISE_INEXACT exact && #endif fpi->rounding == #ifdef RND_PRODQUOT FPI_Round_near #else Flt_Rounds #endif ) goto trunc; goto ret; } switch(rd) { case 1: goto trunc; case 2: break; default: /* round near */ k = bdif - 1; if (!k) { if (!exact) goto ret; if (b->x[0] & 2) break; goto trunc; } if (b->x[(unsigned int)k>>kshift] & ((ULong)1 << (k & kmask))) break; goto trunc; } /* "break" cases: round up 1 bit, then truncate; bdif > 0 */ carry = 1; trunc: inex = lostbits = 0; if (bdif > 0) { if ( (lostbits = any_on(b, bdif)) !=0) inex = STRTOG_Inexlo; rshift(b, bdif); if (carry) { inex = STRTOG_Inexhi; b = increment(b); if ( (j = nb & kmask) !=0) j = ULbits - j; if (hi0bits(b->x[b->wds - 1]) != j) { if (!lostbits) lostbits = b->x[0] & 1; rshift(b, 1); e++; } } } else if (bdif < 0) b = lshift(b, -bdif); if (e < fpi->emin) { k = fpi->emin - e; e = fpi->emin; if (k > nb || fpi->sudden_underflow) { inex = b->wds = 0; *irv = STRTOG_Underflow | STRTOG_Inexlo; } else { k1 = k - 1; if (k1 > 0 && !lostbits) lostbits = any_on(b, k1); if (!lostbits && !exact) goto ret; lostbits |= carry = b->x[(unsigned int)k1>>kshift] & (ULong)(1 << ((unsigned int)k1 & kmask)); rshift(b, k); *irv = STRTOG_Denormal; if (carry) { b = increment(b); inex = STRTOG_Inexhi | STRTOG_Underflow; } else if (lostbits) inex = STRTOG_Inexlo | STRTOG_Underflow; } } else if (e > fpi->emax) { e = fpi->emax + 1; *irv = STRTOG_Infinite | STRTOG_Overflow | STRTOG_Inexhi; #ifndef NO_ERRNO errno = ERANGE; #endif inex = b->wds = 0; } *expt = e; copybits(bits, nb, b); *irv |= inex; rv = 1; ret: Bfree(b); return rv; } #ifndef VAX static int #ifdef KR_headers mantbits(d) double d; #else mantbits(double d) #endif { ULong L; #ifdef VAX L = word1(d) << 16 | word1(d) >> 16; if (L) #else if ( (L = word1(d)) !=0) #endif return P - lo0bits(&L); #ifdef VAX L = word0(d) << 16 | word0(d) >> 16 | Exp_msk11; #else L = word0(d) | Exp_msk1; #endif return P - 32 - lo0bits(&L); } #endif /* !VAX */ int strtodg #ifdef KR_headers (s00, se, fpi, expt, bits) CONST char *s00; char **se; CONST FPI *fpi; Long *expt; ULong *bits; #else (CONST char *s00, char **se, CONST FPI *fpi, Long *expt, ULong *bits) #endif { int abe, abits, asub; int bb0, bb2, bb5, bbe, bd2, bd5, bbbits, bs2, c, decpt, denorm; int dsign, e, e1, e2, emin, esign, finished, i, inex, irv; int j, k, nbits, nd, nd0, nf, nz, nz0, rd, rvbits, rve, rve1, sign; int sudden_underflow = 0; /* pacify gcc */ CONST char *s, *s0, *s1; double adj, adj0, rv, tol; Long L; ULong y, z; Bigint *ab, *bb, *bb1, *bd, *bd0, *bs, *delta, *rvb, *rvb0; e2 = 0; /* XXX gcc */ irv = STRTOG_Zero; denorm = sign = nz0 = nz = 0; dval(rv) = 0.; rvb = 0; nbits = fpi->nbits; for(s = s00;;s++) switch(*s) { case '-': sign = 1; /* FALLTHROUGH */ case '+': if (*++s) goto break2; /* FALLTHROUGH */ case 0: sign = 0; irv = STRTOG_NoNumber; s = s00; goto ret; case '\t': case '\n': case '\v': case '\f': case '\r': case ' ': continue; default: goto break2; } break2: if (*s == '0') { #ifndef NO_HEX_FP switch(s[1]) { case 'x': case 'X': irv = gethex(&s, fpi, expt, &rvb, sign); if (irv == STRTOG_NoNumber) { s = s00; sign = 0; } goto ret; } #endif nz0 = 1; while(*++s == '0') ; if (!*s) goto ret; } sudden_underflow = fpi->sudden_underflow; s0 = s; y = z = 0; for(decpt = 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) { irv = STRTOG_NoNumber; s = s00; goto ret; } s00 = s; esign = 0; switch(c = *++s) { case '-': esign = 1; /* FALLTHROUGH */ 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 */ if (!decpt) switch(c) { case 'i': case 'I': if (match(&s,"nf")) { --s; if (!match(&s,"inity")) ++s; irv = STRTOG_Infinite; goto infnanexp; } break; case 'n': case 'N': if (match(&s, "an")) { irv = STRTOG_NaN; *expt = fpi->emax + 1; #ifndef No_Hex_NaN if (*s == '(') /*)*/ irv = hexnan(&s, fpi, bits); #endif goto infnanexp; } } #endif /* INFNAN_CHECK */ irv = STRTOG_NoNumber; s = s00; } goto ret; } irv = STRTOG_Normal; e1 = e -= nf; rd = 0; switch(fpi->rounding & 3) { case FPI_Round_up: rd = 2 - sign; break; case FPI_Round_zero: rd = 1; break; case FPI_Round_down: rd = 1 + sign; } /* 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) = (double)y; if (k > 9) dval(rv) = tens[k - 9] * dval(rv) + z; bd0 = 0; if (nbits <= P && nd <= DBL_DIG) { if (!e) { if (rvOK(dval(rv), fpi, expt, bits, 1, rd, &irv)) goto ret; } else if (e > 0) { if (e <= Ten_pmax) { #ifdef VAX goto vax_ovfl_check; #else i = fivesbits[e] + mantbits(dval(rv)) <= P; /* rv = */ rounded_product(dval(rv), tens[e]); if (rvOK(dval(rv), fpi, expt, bits, i, rd, &irv)) goto ret; e1 -= e; goto rv_notOK; #endif } i = DBL_DIG - nd; if (e <= Ten_pmax + i) { /* A fancier test would sometimes let us do * this for larger i values. */ e2 = e - i; e1 -= i; dval(rv) *= tens[i]; #ifdef VAX /* VAX exponent range is so narrow we must * worry about overflow here... */ vax_ovfl_check: dval(adj) = dval(rv); word0(adj) -= P*Exp_msk1; /* adj = */ rounded_product(dval(adj), tens[e2]); if ((word0(adj) & Exp_mask) > Exp_msk1*(DBL_MAX_EXP+Bias-1-P)) goto rv_notOK; word0(adj) += P*Exp_msk1; dval(rv) = dval(adj); #else /* rv = */ rounded_product(dval(rv), tens[e2]); #endif if (rvOK(dval(rv), fpi, expt, bits, 0, rd, &irv)) goto ret; e1 -= e2; } } #ifndef Inaccurate_Divide else if (e >= -Ten_pmax) { /* rv = */ rounded_quotient(dval(rv), tens[-e]); if (rvOK(dval(rv), fpi, expt, bits, 0, rd, &irv)) goto ret; e1 -= e; } #endif } rv_notOK: e1 += nd - k; /* Get starting approximation = rv * 10**e1 */ e2 = 0; if (e1 > 0) { if ( (i = e1 & 15) !=0) dval(rv) *= tens[i]; if (e1 &= ~15) { e1 = (unsigned int)e1 >> 4; while(e1 >= (1 << (n_bigtens-1))) { e2 += ((word0(rv) & Exp_mask) >> Exp_shift1) - Bias; word0(rv) &= ~Exp_mask; word0(rv) |= Bias << Exp_shift1; dval(rv) *= bigtens[n_bigtens-1]; e1 -= 1 << (n_bigtens-1); } e2 += ((word0(rv) & Exp_mask) >> Exp_shift1) - Bias; word0(rv) &= ~Exp_mask; word0(rv) |= Bias << Exp_shift1; for(j = 0; e1 > 0; j++, e1 = (unsigned int)e1 >> 1) if (e1 & 1) dval(rv) *= bigtens[j]; } } else if (e1 < 0) { e1 = -e1; if ( (i = e1 & 15) !=0) dval(rv) /= tens[i]; if (e1 &= ~15) { e1 = (unsigned int)e1 >> 4; while(e1 >= (1 << (n_bigtens-1))) { e2 += ((word0(rv) & Exp_mask) >> Exp_shift1) - Bias; word0(rv) &= ~Exp_mask; word0(rv) |= Bias << Exp_shift1; dval(rv) *= tinytens[n_bigtens-1]; e1 -= 1 << (n_bigtens-1); } e2 += ((word0(rv) & Exp_mask) >> Exp_shift1) - Bias; word0(rv) &= ~Exp_mask; word0(rv) |= Bias << Exp_shift1; for(j = 0; e1 > 0; j++, e1 = (unsigned int)e1 >> 1) if (e1 & 1) dval(rv) *= tinytens[j]; } } #ifdef IBM /* e2 is a correction to the (base 2) exponent of the return * value, reflecting adjustments above to avoid overflow in the * native arithmetic. For native IBM (base 16) arithmetic, we * must multiply e2 by 4 to change from base 16 to 2. */ e2 <<= 2; #endif rvb = d2b(dval(rv), &rve, &rvbits); /* rv = rvb * 2^rve */ if (rvb == NULL) return STRTOG_NoMemory; rve += e2; if ((j = rvbits - nbits) > 0) { rshift(rvb, j); rvbits = nbits; rve += j; } bb0 = 0; /* trailing zero bits in rvb */ e2 = rve + rvbits - nbits; if (e2 > fpi->emax + 1) goto huge; rve1 = rve + rvbits - nbits; if (e2 < (emin = fpi->emin)) { denorm = 1; j = rve - emin; if (j > 0) { rvb = lshift(rvb, j); rvbits += j; } else if (j < 0) { rvbits += j; if (rvbits <= 0) { if (rvbits < -1) { ufl: rvb->wds = 0; rvb->x[0] = 0; *expt = emin; irv = STRTOG_Underflow | STRTOG_Inexlo; goto ret; } rvb->x[0] = rvb->wds = rvbits = 1; } else rshift(rvb, -j); } rve = rve1 = emin; if (sudden_underflow && e2 + 1 < emin) goto ufl; } /* 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); if (bd == NULL) return STRTOG_NoMemory; Bcopy(bd, bd0); bb = Balloc(rvb->k); if (bb == NULL) return STRTOG_NoMemory; Bcopy(bb, rvb); bbbits = rvbits - bb0; bbe = rve + bb0; bs = i2b(1); if (bs == NULL) return STRTOG_NoMemory; 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; j = nbits + 1 - bbbits; i = bbe + bbbits - nbits; if (i < emin) /* denormal */ j += i - emin; bb2 += j; bd2 += j; 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); if (bs == NULL) return STRTOG_NoMemory; bb1 = mult(bs, bb); if (bb1 == NULL) return STRTOG_NoMemory; Bfree(bb); bb = bb1; } bb2 -= bb0; if (bb2 > 0) { bb = lshift(bb, bb2); if (bb == NULL) return STRTOG_NoMemory; } else if (bb2 < 0) rshift(bb, -bb2); if (bd5 > 0) { bd = pow5mult(bd, bd5); if (bd == NULL) return STRTOG_NoMemory; } if (bd2 > 0) { bd = lshift(bd, bd2); if (bd == NULL) return STRTOG_NoMemory; } if (bs2 > 0) { bs = lshift(bs, bs2); if (bs == NULL) return STRTOG_NoMemory; } asub = 1; inex = STRTOG_Inexhi; delta = diff(bb, bd); if (delta == NULL) return STRTOG_NoMemory; if (delta->wds <= 1 && !delta->x[0]) break; dsign = delta->sign; delta->sign = finished = 0; L = 0; i = cmp(delta, bs); if (rd && i <= 0) { irv = STRTOG_Normal; if ( (finished = dsign ^ (rd&1)) !=0) { if (dsign != 0) { irv |= STRTOG_Inexhi; goto adj1; } irv |= STRTOG_Inexlo; if (rve1 == emin) goto adj1; for(i = 0, j = nbits; j >= ULbits; i++, j -= ULbits) { if (rvb->x[i] & ALL_ON) goto adj1; } if (j > 1 && lo0bits(rvb->x + i) < j - 1) goto adj1; rve = rve1 - 1; rvb = set_ones(rvb, rvbits = nbits); if (rvb == NULL) return STRTOG_NoMemory; break; } irv |= dsign ? STRTOG_Inexlo : STRTOG_Inexhi; break; } if (i < 0) { /* Error is less than half an ulp -- check for * special case of mantissa a power of two. */ irv = dsign ? STRTOG_Normal | STRTOG_Inexlo : STRTOG_Normal | STRTOG_Inexhi; if (dsign || bbbits > 1 || denorm || rve1 == emin) break; delta = lshift(delta,1); if (delta == NULL) return STRTOG_NoMemory; if (cmp(delta, bs) > 0) { irv = STRTOG_Normal | STRTOG_Inexlo; goto drop_down; } break; } if (i == 0) { /* exactly half-way between */ if (dsign) { if (denorm && all_on(rvb, rvbits)) { /*boundary case -- increment exponent*/ rvb->wds = 1; rvb->x[0] = 1; rve = emin + nbits - (rvbits = 1); irv = STRTOG_Normal | STRTOG_Inexhi; denorm = 0; break; } irv = STRTOG_Normal | STRTOG_Inexlo; } else if (bbbits == 1) { irv = STRTOG_Normal; drop_down: /* boundary case -- decrement exponent */ if (rve1 == emin) { irv = STRTOG_Normal | STRTOG_Inexhi; if (rvb->wds == 1 && rvb->x[0] == 1) sudden_underflow = 1; break; } rve -= nbits; rvb = set_ones(rvb, rvbits = nbits); if (rvb == NULL) return STRTOG_NoMemory; break; } else irv = STRTOG_Normal | STRTOG_Inexhi; if ((bbbits < nbits && !denorm) || !(rvb->x[0] & 1)) break; if (dsign) { rvb = increment(rvb); if (rvb == NULL) return STRTOG_NoMemory; if ( (j = rvbits & kmask) !=0) j = ULbits - j; if (hi0bits(rvb->x[(unsigned int)(rvb->wds - 1) >> kshift]) != j) rvbits++; irv = STRTOG_Normal | STRTOG_Inexhi; } else { if (bbbits == 1) goto undfl; decrement(rvb); irv = STRTOG_Normal | STRTOG_Inexlo; } break; } if ((dval(adj) = ratio(delta, bs)) <= 2.) { adj1: inex = STRTOG_Inexlo; if (dsign) { asub = 0; inex = STRTOG_Inexhi; } else if (denorm && bbbits <= 1) { undfl: rvb->wds = 0; rve = emin; irv = STRTOG_Underflow | STRTOG_Inexlo; break; } adj0 = dval(adj) = 1.; } else { adj0 = dval(adj) *= 0.5; if (dsign) { asub = 0; inex = STRTOG_Inexlo; } if (dval(adj) < 2147483647.) { L = (INT32)adj0; adj0 -= L; switch(rd) { case 0: if (adj0 >= .5) goto inc_L; break; case 1: if (asub && adj0 > 0.) goto inc_L; break; case 2: if (!asub && adj0 > 0.) { inc_L: L++; inex = STRTOG_Inexact - inex; } } dval(adj) = (double)L; } } y = rve + rvbits; /* adj *= ulp(dval(rv)); */ /* if (asub) rv -= adj; else rv += adj; */ if (!denorm && rvbits < nbits) { rvb = lshift(rvb, j = nbits - rvbits); if (rvb == NULL) return STRTOG_NoMemory; rve -= j; rvbits = nbits; } ab = d2b(dval(adj), &abe, &abits); if (ab == NULL) return STRTOG_NoMemory; if (abe < 0) rshift(ab, -abe); else if (abe > 0) ab = lshift(ab, abe); rvb0 = rvb; if (asub) { /* rv -= adj; */ j = hi0bits(rvb->x[rvb->wds-1]); rvb = diff(rvb, ab); if (rvb == NULL) return STRTOG_NoMemory; k = rvb0->wds - 1; if (denorm) /* do nothing */; else if (rvb->wds <= k || hi0bits( rvb->x[k]) > hi0bits(rvb0->x[k])) { /* unlikely; can only have lost 1 high bit */ if (rve1 == emin) { --rvbits; denorm = 1; } else { rvb = lshift(rvb, 1); if (rvb == NULL) return STRTOG_NoMemory; --rve; --rve1; L = finished = 0; } } } else { rvb = sum(rvb, ab); if (rvb == NULL) return STRTOG_NoMemory; k = rvb->wds - 1; if (k >= rvb0->wds || hi0bits(rvb->x[k]) < hi0bits(rvb0->x[k])) { if (denorm) { if (++rvbits == nbits) denorm = 0; } else { rshift(rvb, 1); rve++; rve1++; L = 0; } } } Bfree(ab); Bfree(rvb0); if (finished) break; z = rve + rvbits; if (y == z && L) { /* Can we stop now? */ tol = dval(adj) * 5e-16; /* > max rel error */ dval(adj) = adj0 - .5; if (dval(adj) < -tol) { if (adj0 > tol) { irv |= inex; break; } } else if (dval(adj) > tol && adj0 < 1. - tol) { irv |= inex; break; } } bb0 = denorm ? 0 : trailz(rvb); Bfree(bb); Bfree(bd); Bfree(bs); Bfree(delta); } if (!denorm && (j = nbits - rvbits)) { if (j > 0) rvb = lshift(rvb, j); else rshift(rvb, -j); rve -= j; } *expt = rve; Bfree(bb); Bfree(bd); Bfree(bs); Bfree(bd0); Bfree(delta); if (rve > fpi->emax) { huge: rvb->wds = 0; irv = STRTOG_Infinite | STRTOG_Overflow | STRTOG_Inexhi; #ifndef NO_ERRNO errno = ERANGE; #endif #ifdef INFNAN_CHECK infnanexp: #endif *expt = fpi->emax + 1; } ret: if (denorm) { if (sudden_underflow) { rvb->wds = 0; irv = STRTOG_Underflow | STRTOG_Inexlo; } else { irv = (irv & ~STRTOG_Retmask) | (rvb->wds > 0 ? STRTOG_Denormal : STRTOG_Zero); if (irv & STRTOG_Inexact) irv |= STRTOG_Underflow; } } if (se) *se = __UNCONST(s); if (sign) irv |= STRTOG_Neg; if (rvb) { copybits(bits, nbits, rvb); Bfree(rvb); } return irv; }