[Bug tree-optimization/88074] [7/8/9 Regression] g++ hangs on math expression

[joseph at codesourcery dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88074

--- Comment #22 from joseph at codesourcery dot com <joseph at codesourcery dot com> ---
On Wed, 21 Nov 2018, rguenther at suse dot de wrote:

>       /* Nonzero value, possibly overflowing or underflowing.  */
>       mpfr_init2 (m, SIGNIFICAND_BITS);
>       inexact = mpfr_strtofr (m, str, NULL, 10, GMP_RNDZ);
> 
> we return true and the rounding mode is GMP_RNDZ?  Indeed when changing
> the above to use GMP_RNDN it works OK.  The whole thing is also a bit

Note that using RNDZ is required there for correctness (this is 
round-to-odd / sticky rounding).