diff options
Diffstat (limited to 'gcc/toplev.c')
| -rw-r--r-- | gcc/toplev.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/gcc/toplev.c b/gcc/toplev.c index b066bcc7229..bdf021e828a 100644 --- a/gcc/toplev.c +++ b/gcc/toplev.c @@ -2110,6 +2110,34 @@ do_compile () else int_n_enabled_p[i] = false; + /* Initialize mpfrs exponent range. This is important to get + underflow/overflow in a reasonable timeframe. */ + machine_mode mode; + int min_exp = -1; + int max_exp = 1; + FOR_EACH_MODE_IN_CLASS (mode, MODE_FLOAT) + if (SCALAR_FLOAT_MODE_P (mode)) + { + const real_format *fmt = REAL_MODE_FORMAT (mode); + if (fmt) + { + /* fmt->emin - fmt->p + 1 should be enough but the + back-and-forth dance in real_to_decimal_for_mode we + do for checking fails due to rounding effects then. */ + if ((fmt->emin - fmt->p) < min_exp) + min_exp = fmt->emin - fmt->p; + if (fmt->emax > max_exp) + max_exp = fmt->emax; + } + } + /* E.g. mpc_norm assumes it can square a number without bothering with + with range scaling, so until that is fixed, double the minimum + and maximum exponents, plus add some buffer for arithmetics + on the squared numbers. */ + if (mpfr_set_emin (2 * (min_exp - 1)) + || mpfr_set_emax (2 * (max_exp + 1))) + sorry ("mpfr not configured to handle all float modes"); + /* Set up the back-end if requested. */ if (!no_backend) backend_init (); |