static bool
fold_const_builtin_load_exponent (real_value *result, const real_value *arg0,
const wide_int_ref &arg1,
const real_format *format)
{
/* Bound the maximum adjustment to twice the range of the
mode's valid exponents. Use abs to ensure the range is
positive as a sanity check. */
int max_exp_adj = 2 * labs (format->emax - format->emin);
/* The requested adjustment must be inside this range. This
is a preliminary cap to avoid things like overflow, we
may still fail to compute the result for other reasons. */
if (wi::les_p (arg1, -max_exp_adj) || wi::ges_p (arg1, max_exp_adj))
return false;
REAL_VALUE_TYPE initial_result;
real_ldexp (&initial_result, arg0, arg1.to_shwi ());
/* Ensure we didn't overflow. */
if (real_isinf (&initial_result))
return false;
/* Only proceed if the target mode can hold the
resulting value. */
*result = real_value_truncate (format, initial_result);
return real_equal (&initial_result, result);
}
static bool
fold_const_call_sss (real_value *result, combined_fn fn,
const real_value *arg0, const wide_int_ref &arg1,
const real_format *format)
{
switch (fn)
{
CASE_CFN_LDEXP:
return fold_const_builtin_load_exponent (result, arg0, arg1, format);
CASE_CFN_SCALBN:
CASE_CFN_SCALBLN:
return (format->b == 2
&& fold_const_builtin_load_exponent (result, arg0, arg1,
format));
CASE_CFN_POWI:
/* Avoid the folding if flag_signaling_nans is on and
operand is a signaling NaN. */
if (!flag_unsafe_math_optimizations
&& flag_signaling_nans
&& REAL_VALUE_ISSIGNALING_NAN (*arg0))
return false;
real_powi (result, format, arg0, arg1.to_shwi ());
return true;
default:
return false;
}
}
static bool
do_mpfr_arg2 (real_value *result,
int (*func) (mpfr_ptr, long, mpfr_srcptr, mp_rnd_t),
const wide_int_ref &arg0, const real_value *arg1,
const real_format *format)
{
if (format->b != 2 || !real_isfinite (arg1))
return false;
int prec = format->p;
mp_rnd_t rnd = format->round_towards_zero ? GMP_RNDZ : GMP_RNDN;
mpfr_t m;
mpfr_init2 (m, prec);
mpfr_from_real (m, arg1, GMP_RNDN);
mpfr_clear_flags ();
bool inexact = func (m, arg0.to_shwi (), m, rnd);
bool ok = do_mpfr_ckconv (result, m, inexact, format);
mpfr_clear (m);
return ok;
}
static bool
fold_const_call_sss (real_value *result, built_in_function fn,
const real_value *arg0, const wide_int_ref &arg1,
const real_format *format)
{
switch (fn)
{
CASE_FLT_FN (BUILT_IN_LDEXP):
return fold_const_builtin_load_exponent (result, arg0, arg1, format);
CASE_FLT_FN (BUILT_IN_SCALBN):
CASE_FLT_FN (BUILT_IN_SCALBLN):
return (format->b == 2
&& fold_const_builtin_load_exponent (result, arg0, arg1,
format));
CASE_FLT_FN (BUILT_IN_POWI):
real_powi (result, format, arg0, arg1.to_shwi ());
return true;
default:
return false;
}
}
