Re: [PATCH] i386: Expand roundeven for SSE4.1+

[Uros Bizjak <ubizjak at gmail dot com>]

> This patch is for expanding roundeven inline for SSE4.1 and later.
> Note that this patch is to be applied on top of
> <https://gcc.gnu.org/ml/gcc-patches/2019-06/msg01828.html>. The patch
> is bootstrapped and regression tested on x86_64-linux-gnu.

Actually, your patch at [1] is the way to go, but you need several
other changes to get x87 mode switching in order. Please also note
that there is no corresponding non-SSE4 ix86_expand_... function for
roundeven, so non-SSE4 SSE FP-math <rounding_insn><mode>2 expander has
to be disabled for ROUNDEVEN int iterator. Please see (otherwise
untested) attached patch which fixes both issues.

[1] https://gcc.gnu.org/ml/gcc/2019-06/msg00352.html

Uros.

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