diff options
Diffstat (limited to 'newlib/libc/stdlib/strtod.c')
| -rw-r--r-- | newlib/libc/stdlib/strtod.c | 155 |
1 files changed, 117 insertions, 38 deletions
diff --git a/newlib/libc/stdlib/strtod.c b/newlib/libc/stdlib/strtod.c index fe6aac206..159c9695b 100644 --- a/newlib/libc/stdlib/strtod.c +++ b/newlib/libc/stdlib/strtod.c @@ -128,11 +128,17 @@ THIS SOFTWARE. #ifndef NO_IEEE_Scale #define Avoid_Underflow #undef tinytens -/* The factor of 2^53 in tinytens[4] helps us avoid setting the underflow */ +/* The factor of 2^106 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 - }; +static _CONST double tinytens[] = { 1e-16, 1e-32, +#ifdef _DOUBLE_IS_32BITS + 0.0, 0.0, 0.0 +#else + 1e-64, 1e-128, + 9007199254740992. * 9007199254740992.e-256 +#endif + }; + #endif #endif @@ -144,6 +150,28 @@ static _CONST double tinytens[] = { 1e-16, 1e-32, 1e-64, 1e-128, #define Rounding Flt_Rounds #endif +#ifdef Avoid_Underflow /*{*/ + static double +_DEFUN (sulp, (x, scale), + U x _AND + int scale) +{ + U u; + double rv; + int i; + + rv = ulp(dval(x)); + if (!scale || (i = 2*P + 1 - ((dword0(x) & Exp_mask) >> Exp_shift)) <= 0) + return rv; /* Is there an example where i <= 0 ? */ + dword0(u) = Exp_1 + (i << Exp_shift); +#ifndef _DOUBLE_IS_32BITS + dword1(u) = 0; +#endif + return rv * u.d; + } +#endif /*}*/ + + #ifndef NO_HEX_FP static void @@ -221,7 +249,10 @@ _DEFUN (_strtod_r, (ptr, s00, se), U aadj1, rv, rv0; Long L; __ULong y, z; - _Bigint *bb, *bb1, *bd, *bd0, *bs, *delta; + _Bigint *bb = NULL, *bb1, *bd = NULL, *bd0, *bs = NULL, *delta = NULL; +#ifdef Avoid_Underflow + __ULong Lsb, Lsb1; +#endif #ifdef SET_INEXACT int inexact, oldinexact; #endif @@ -279,6 +310,8 @@ _DEFUN (_strtod_r, (ptr, s00, se), switch((i = gethex(ptr, &s, &fpi1, &exp, &bb, sign)) & STRTOG_Retmask) { case STRTOG_NoNumber: s = s00; + sign = 0; + /* FALLTHROUGH */ case STRTOG_Zero: break; default: @@ -299,14 +332,11 @@ _DEFUN (_strtod_r, (ptr, s00, se), } s0 = s; y = z = 0; - for(nd = nf = 0; (c = *s) >= '0' && c <= '9'; nd++, s++) { - if (nd < DBL_DIG + 1) { - if (nd < 9) - y = 10*y + c - '0'; - else - z = 10*z + c - '0'; - } - } + for(nd = nf = 0; (c = *s) >= '0' && c <= '9'; nd++, s++) + if (nd < 9) + y = 10*y + c - '0'; + else + z = 10*z + c - '0'; nd0 = nd; if (strncmp (s, _localeconv_r (ptr)->decimal_point, strlen (_localeconv_r (ptr)->decimal_point)) == 0) @@ -329,20 +359,15 @@ _DEFUN (_strtod_r, (ptr, s00, se), nz++; if (c -= '0') { nf += nz; - for(i = 1; i < nz; i++) { - if (nd++ <= DBL_DIG + 1) { - if (nd < 10) - y *= 10; - else - z *= 10; - } - } - if (nd++ <= DBL_DIG + 1) { - if (nd < 10) - y = 10*y + c; - else - z = 10*z + c; - } + 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; } } @@ -691,12 +716,20 @@ _DEFUN (_strtod_r, (ptr, s00, se), /* Put digits into bd: true value = bd * 10^e */ bd0 = s2b(ptr, s0, nd0, nd, y); + if (bd0 == NULL) + goto ovfl; for(;;) { bd = Balloc(ptr,bd0->_k); + if (bd == NULL) + goto ovfl; Bcopy(bd, bd0); bb = d2b(ptr,dval(rv), &bbe, &bbbits); /* rv = bb * 2^bbe */ + if (bb == NULL) + goto ovfl; bs = i2b(ptr,1); + if (bs == NULL) + goto ovfl; if (e >= 0) { bb2 = bb5 = 0; @@ -716,12 +749,19 @@ _DEFUN (_strtod_r, (ptr, s00, se), bs2++; #endif #ifdef Avoid_Underflow + Lsb = LSB; + Lsb1 = 0; j = bbe - scale; i = j + bbbits - 1; /* logb(rv) */ - if (i < Emin) /* denormal */ - j += P - Emin; - else - j = P + 1 - bbbits; + j = P + 1 - bbbits; + if (i < Emin) { /* denormal */ + i = Emin - i; + j -= i; + if (i < 32) + Lsb <<= i; + else + Lsb1 = Lsb << (i-32); + } #else /*Avoid_Underflow*/ #ifdef Sudden_Underflow #ifdef IBM @@ -753,19 +793,37 @@ _DEFUN (_strtod_r, (ptr, s00, se), } if (bb5 > 0) { bs = pow5mult(ptr, bs, bb5); + if (bs == NULL) + goto ovfl; bb1 = mult(ptr, bs, bb); + if (bb1 == NULL) + goto ovfl; Bfree(ptr, bb); bb = bb1; } - if (bb2 > 0) + if (bb2 > 0) { bb = lshift(ptr, bb, bb2); - if (bd5 > 0) + if (bb == NULL) + goto ovfl; + } + if (bd5 > 0) { bd = pow5mult(ptr, bd, bd5); - if (bd2 > 0) + if (bd == NULL) + goto ovfl; + } + if (bd2 > 0) { bd = lshift(ptr, bd, bd2); - if (bs2 > 0) + if (bd == NULL) + goto ovfl; + } + if (bs2 > 0) { bs = lshift(ptr, bs, bs2); + if (bs == NULL) + goto ovfl; + } delta = diff(ptr, bb, bd); + if (delta == NULL) + goto ovfl; dsign = delta->_sign; delta->_sign = 0; i = cmp(delta, bs); @@ -789,7 +847,7 @@ _DEFUN (_strtod_r, (ptr, s00, se), else if (!dsign) { adj = -1.; if (!dword1(rv) - && !(dword0(rv) & Frac_mask)) { + && !(dword0(rv) & Frac_mask)) { y = dword0(rv) & Exp_mask; #ifdef Avoid_Underflow if (!scale || y > 2*P*Exp_msk1) @@ -852,7 +910,9 @@ _DEFUN (_strtod_r, (ptr, s00, se), #endif /*Sudden_Underflow*/ #endif /*Avoid_Underflow*/ adj *= ulp(dval(rv)); - if (dsign) + if (dsign) { + if (dword0(rv) == Big0 && dword1(rv) == Big1) + goto ovfl; dval(rv) += adj; else dval(rv) -= adj; @@ -902,6 +962,8 @@ _DEFUN (_strtod_r, (ptr, s00, se), #endif 0xffffffff)) { /*boundary case -- increment exponent*/ + if (dword0(rv) == Big0 && dword1(rv) == Big1) + goto ovfl; dword0(rv) = (dword0(rv) & Exp_mask) + Exp_msk1 #ifdef IBM @@ -960,14 +1022,31 @@ _DEFUN (_strtod_r, (ptr, s00, se), #endif } #ifndef ROUND_BIASED +#ifdef Avoid_Underflow + if (Lsb1) { + if (!(dword0(rv) & Lsb1)) + break; + } + else if (!(dword1(rv) & Lsb)) + break; +#else if (!(dword1(rv) & LSB)) break; #endif +#endif if (dsign) +#ifdef Avoid_Underflow + dval(rv) += sulp(rv, scale); +#else dval(rv) += ulp(dval(rv)); +#endif #ifndef ROUND_BIASED else { +#ifdef Avoid_Underflow + dval(rv) -= sulp(rv, scale); +#else dval(rv) -= ulp(dval(rv)); +#endif #ifndef Sudden_Underflow if (!dval(rv)) goto undfl; @@ -1044,7 +1123,7 @@ _DEFUN (_strtod_r, (ptr, s00, se), #ifdef Avoid_Underflow if (scale && y <= 2*P*Exp_msk1) { if (aadj <= 0x7fffffff) { - if ((z = aadj) <= 0) + if ((z = aadj) == 0) z = 1; aadj = z; dval(aadj1) = dsign ? aadj : -aadj; |