Re: Go patch committed: Avoid negative zero in float constants

[Ian Lance Taylor <iant at golang dot org>]

On Mon, Feb 5, 2018 at 11:26 AM, Ian Lance Taylor <iant@golang.org> wrote:
> On Mon, Feb 5, 2018 at 10:47 AM, Rainer Orth
> <ro@cebitec.uni-bielefeld.de> wrote:
>>
>>> This patch to the Go frontend checks for negative numbers with very
>>> small magnitudes that will round to negative zero, and forces them to
>>> positive zero instead.  This implements the spec clarification in
>>> https://golang.org/cl/14727.  The test is in
>>> https://golang.org/cl/91895.  This fixes golang.org/issue/12621.
>>> Bootstrapped and ran Go testsuite on x86_64-pc-linux-gnu.  Committed
>>> to mainline.
>>
>> unfortunately, this broke bootstrap with mpfr 2.4.2, which is still the
>> minimum version documented in install.texi:
>
> Bother.  Thanks for the note.  I've rolled back the patch, as follows.

I have now reimplemented the patch, using only MPFR 2.4.2 API.  This
version is better anyhow.  Committed as follows after testing.

Ian

Attachment: patch.txt
Description: Text document