commit 98b3cff7537ad2a9ce0faa6ad0af4191bd066916
author Richard Henderson <richard.henderson@linaro.org> Sat Nov 21 16:35:54 2020 -0800
committer Richard Henderson <richard.henderson@linaro.org> Thu Jun 03 14:09:02 2021 -0700
tree 1268113bf435285c52033e27e75224f3ba155ce4
parent 8da5f1dbb0d7b97686d54584c70b55cb05f89007

softfloat: Adjust parts_uncanon_normal for floatx80

With floatx80_precision_x, the rounding happens across
the break between words.  Notice this case with

  frac_lsb = round_mask + 1 -> 0

and check the bits in frac_hi as needed.

In addition, since frac_shift == 0, we won't implicitly clear
round_mask via the right-shift, so explicitly clear those bits.
This fixes rounding for floatx80_precision_[sd].

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>