Date: prev next · Thread: first prev next last
2017 Archives by date, by thread · List index


Hi Milton,

On Saturday, 2017-12-02 02:47:03 -0500, Milton Vandersloot wrote:

The issue seems to be (again) floating point precision. Indeed, I've compiled LibreOffice with 
FMA (fused multiply-add) instructions, if I disable them, i.e. passing -ffp-contract=off to GCC, 
then the tests succeed. Note that FMA has slightly different floating point precision than 
ordinary plus and mult [0, 1].

From what I understood by browsing shortly gcc enables this by default
for -std=gnu* and it can be unset by

#pragma STDC FP_CONTRACT OFF

https://stackoverflow.com/questions/15933100/how-to-use-fused-multiply-add-fma-instructions-with-sse-avx#15933677

Could you try if adding the pragma to include/sal/config.h helps?

Thanks
  Eike

-- 
LibreOffice Calc developer. Number formatter stricken i18n transpositionizer.
GPG key 0x6A6CD5B765632D3A - 2265 D7F3 A7B0 95CC 3918  630B 6A6C D5B7 6563 2D3A
Care about Free Software, support the FSFE https://fsfe.org/support/?erack

Attachment: signature.asc
Description: PGP signature


Context


Privacy Policy | Impressum (Legal Info) | Copyright information: Unless otherwise specified, all text and images on this website are licensed under the Creative Commons Attribution-Share Alike 3.0 License. This does not include the source code of LibreOffice, which is licensed under the Mozilla Public License (MPLv2). "LibreOffice" and "The Document Foundation" are registered trademarks of their corresponding registered owners or are in actual use as trademarks in one or more countries. Their respective logos and icons are also subject to international copyright laws. Use thereof is explained in our trademark policy.