diff options
Diffstat (limited to 'mpfr.c')
| -rw-r--r-- | mpfr.c | 22 |
1 files changed, 17 insertions, 5 deletions
@@ -39,6 +39,8 @@ mpz_t MFNR; bool do_ieee_fmt; /* IEEE-754 floating-point emulation */ mpfr_rnd_t ROUND_MODE; +static mpfr_prec_t default_prec; + static mpfr_rnd_t get_rnd_mode(const char rmode); static NODE *mpg_force_number(NODE *n); static NODE *mpg_make_number(double); @@ -70,7 +72,7 @@ static inline mpfr_ptr mpg_tofloat(mpfr_ptr mf, mpz_ptr mz); void init_mpfr(mpfr_prec_t prec, const char *rmode) { - mpfr_set_default_prec(prec); + mpfr_set_default_prec(default_prec = prec); ROUND_MODE = get_rnd_mode(rmode[0]); mpfr_set_default_rounding_mode(ROUND_MODE); make_number = mpg_make_number; @@ -557,7 +559,7 @@ set_PREC() } if (prec > 0) - mpfr_set_default_prec(prec); + mpfr_set_default_prec(default_prec = prec); } @@ -701,6 +703,7 @@ do_mpfr_func(const char *name, NODE *t1, *res; mpfr_ptr p1; int tval; + mpfr_prec_t argprec; t1 = POP_SCALAR(); if (do_lint && (fixtype(t1)->flags & NUMBER) == 0) @@ -709,7 +712,8 @@ do_mpfr_func(const char *name, force_number(t1); p1 = MP_FLOAT(t1); res = mpg_float(); - mpfr_set_prec(res->mpg_numbr, mpfr_get_prec(p1)); /* needed at least for sqrt() */ + if ((argprec = mpfr_get_prec(p1)) > default_prec) + mpfr_set_prec(res->mpg_numbr, argprec); /* needed at least for sqrt() */ tval = mpfr_func(res->mpg_numbr, p1, ROUND_MODE); IEEE_FMT(res->mpg_numbr, tval); DEREF(t1); @@ -1296,9 +1300,17 @@ mpg_tofloat(mpfr_ptr mf, mpz_ptr mz) prec -= (size_t) mpz_scan1(mz, 0); /* least significant 1 bit index starting at 0 */ if (prec > MPFR_PREC_MAX) prec = MPFR_PREC_MAX; - if (prec > PRECISION_MIN) - mpfr_set_prec(mf, prec); + else if (prec < PRECISION_MIN) + prec = PRECISION_MIN; } + else + prec = PRECISION_MIN; + /* + * Always set the precision to avoid hysteresis, since do_mpfr_func + * may copy our precision. + */ + if (prec != mpfr_get_prec(mf)) + mpfr_set_prec(mf, prec); mpfr_set_z(mf, mz, ROUND_MODE); return mf; |