diff options
| -rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/e_expl.c | 34 | ||||
| -rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/w_expl.c | 46 |
2 files changed, 64 insertions, 16 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/e_expl.c b/sysdeps/ieee754/ldbl-128ibm/e_expl.c index 8236390..60229d5 100644 --- a/sysdeps/ieee754/ldbl-128ibm/e_expl.c +++ b/sysdeps/ieee754/ldbl-128ibm/e_expl.c @@ -70,11 +70,11 @@ static const long double C[] = { /* Smallest integer x for which e^x overflows. */ #define himark C[0] - 709.08956571282405153382846025171462914L, + 709.78271289338399678773454114191496482L, /* Largest integer x for which e^x underflows. */ #define lomark C[1] --744.44007192138121808966388925909996033L, +-744.44007192138126231410729844608163411L, /* 3x2^96 */ #define THREEp96 C[2] @@ -138,14 +138,12 @@ __ieee754_expl (long double x) if (isless (x, himark) && isgreater (x, lomark)) { int tval1, tval2, unsafe, n_i, exponent2; - long double x22, n, result, xl; - union ibm_extended_long_double ex2_u, scale_u; + long double x22, n, xl; + union ibm_extended_long_double ex2_u, scale_u, result; fenv_t oldenv; feholdexcept (&oldenv); -#ifdef FE_TONEAREST fesetround (FE_TONEAREST); -#endif n = __roundl (x*M_1_LN2); x = x-n*M_LN2_0; @@ -166,7 +164,7 @@ __ieee754_expl (long double x) * __expl_table[T_EXPL_RES2 + tval2]; n_i = (int)n; /* 'unsafe' is 1 iff n_1 != 0. */ - unsafe = fabsl(n_i) >= -LDBL_MIN_EXP - 1; + unsafe = abs (n_i) >= -LDBL_MIN_EXP - 1; ex2_u.ieee.exponent += n_i >> unsafe; /* Fortunately, there are no subnormal lowpart doubles in __expl_table, only normal values and zeros. @@ -204,7 +202,7 @@ __ieee754_expl (long double x) /* Return result. */ fesetenv (&oldenv); - result = x22 * ex2_u.d + ex2_u.d; + result.d = x22 * ex2_u.d + ex2_u.d; /* Now we can test whether the result is ultimate or if we are unsure. In the later case we should probably call a mpn based routine to give @@ -235,10 +233,22 @@ __ieee754_expl (long double x) return __ieee754_expl_proc2 (origx); } */ - if (!unsafe) - return result; - else - return result * scale_u.d; + if (unsafe) + { + /* The scale with denormal number might generated underflow for + first high double multiplication. The exception holding is + to avoid it. */ + if (result.ieee.exponent + scale_u.ieee.exponent + < IBM_EXTENDED_LONG_DOUBLE_BIAS) + { + feholdexcept (&oldenv); + result.d *= scale_u.d; + fesetenv (&oldenv); + } + else + result.d *= scale_u.d; + } + return result.d; } /* Exceptional cases: */ else if (isless (x, himark)) diff --git a/sysdeps/ieee754/ldbl-128ibm/w_expl.c b/sysdeps/ieee754/ldbl-128ibm/w_expl.c index a5e72b2..c00b311 100644 --- a/sysdeps/ieee754/ldbl-128ibm/w_expl.c +++ b/sysdeps/ieee754/ldbl-128ibm/w_expl.c @@ -1,6 +1,44 @@ -/* Looks like we can use ieee854 w_expl.c as is for IBM extended format. */ +/* + * ==================================================== + * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. + * + * Developed at SunPro, a Sun Microsystems, Inc. business. + * Permission to use, copy, modify, and distribute this + * software is freely granted, provided that this notice + * is preserved. + * ==================================================== + */ + + +#include <math.h> +#include <math_private.h> #include <math_ldbl_opt.h> -#undef weak_alias -#define weak_alias(n,a) -#include <sysdeps/ieee754/ldbl-128/w_expl.c> + +/* + * wrapper expl(x) + */ +static const long double +o_threshold = 709.78271289338399678773454114191496482L, +u_threshold = -744.44007192138126231410729844608163411L; + +long double __expl(long double x) /* wrapper exp */ +{ +#ifdef _IEEE_LIBM + return __ieee754_expl(x); +#else + long double z; + z = __ieee754_expl(x); + if (_LIB_VERSION == _IEEE_) + return z; + if (__finitel(x)) + { + if (x >= o_threshold) + return __kernel_standard_l(x,x,206); /* exp overflow */ + else if (x <= u_threshold) + return __kernel_standard_l(x,x,207); /* exp underflow */ + } + return z; +#endif +} +hidden_def (__expl) long_double_symbol (libm, __expl, expl); |