diff options
Diffstat (limited to 'libquadmath/math/expq.c')
| -rw-r--r-- | libquadmath/math/expq.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/libquadmath/math/expq.c b/libquadmath/math/expq.c index a5fbc810269..2740b4e2cc9 100644 --- a/libquadmath/math/expq.c +++ b/libquadmath/math/expq.c @@ -21,6 +21,13 @@ 02111-1307 USA. */ #include "quadmath-imp.h" +#ifdef HAVE_FENV_H +# include <fenv.h> +# if defined HAVE_FEHOLDEXCEPT && defined HAVE_FESETROUND \ + && defined HAVE_FESETENV && defined FE_TONEAREST +# define USE_FENV_H +# endif +#endif /* __expl_table basically consists of four tables, T_EXPL_ARG{1,2} and @@ -1093,6 +1100,14 @@ expq (__float128 x) int tval1, tval2, unsafe, n_i; __float128 x22, n, t, result, xl; ieee854_float128 ex2_u, scale_u; +#ifdef USE_FENV_H + fenv_t oldenv; + + feholdexcept (&oldenv); +# ifdef FE_TONEAREST + fesetround (FE_TONEAREST); +# endif +#endif /* Calculate n. */ n = x * M_1_LN2 + THREEp111; @@ -1140,6 +1155,9 @@ expq (__float128 x) x22 = x + x*x*(P1+x*(P2+x*(P3+x*(P4+x*(P5+x*P6))))); /* Return result. */ +#ifdef USE_FENV_H + fesetenv (&oldenv); +#endif result = x22 * ex2_u.value + ex2_u.value; /* Now we can test whether the result is ultimate or if we are unsure. @@ -1153,12 +1171,24 @@ expq (__float128 x) union ieee854_long_double ex3_u; +#ifdef USE_FENV_H + #ifdef FE_TONEAREST + fesetround (FE_TONEAREST); + #endif +#endif ex3_u.d = (result - ex2_u.d) - x22 * ex2_u.d; ex2_u.d = result; ex3_u.ieee.exponent += LDBL_MANT_DIG + 15 + IEEE854_LONG_DOUBLE_BIAS - ex2_u.ieee.exponent; n_i = abs (ex3_u.d); n_i = (n_i + 1) / 2; +#ifdef USE_FENV_H + fesetenv (&oldenv); + #ifdef FE_TONEAREST + if (fegetround () == FE_TONEAREST) + n_i -= 0x4000; + #endif +#endif if (!n_i) { return __ieee754_expl_proc2 (origx); } |