Comment 0 for bug 1717257

Here is another proposal regarding bug report I posted (but in reject).
https://bugs.launchpad.net/ubuntu/+source/glibc/+bug/1716816

I reported that glibc 2.26-0ubuntu1 ( adopted in Artful-proposed on Sep 5.) causes compilation error by using NVIDIA's CUDA8.0 and 9.0RC.

Under glibc 2.24, they work.

It maybe comes from glibc226's new feature, i.e. "128-bit floating point as defined by ISO/IEC/IEEE 60559:2011 (IEEE 754-2008) and ISO/IEC TS 18661-3:2015" . (Evidence Scripted at bottom)

I proposed the patch to

  /usr/include/x86_64-linux-gnu/bits/floatn.h

which lets NVCC (CUDA's compiler) avoid __float128 (NVCC does support neither 8.0 nor 9.0).

So can the patch be merged to glibc2.25 be adopted in Arful or later?

-------------------------------------------------------------------------------------
*** floatn.h-dist 2017-09-04 16:34:21.000000000 +0900
--- floatn.h 2017-09-14 21:46:15.334033614 +0900
***************
*** 28,34 ****
     support, for x86_64 and x86. */
  #if (defined __x86_64__ \
       ? __GNUC_PREREQ (4, 3) \
! : (defined __GNU__ ? __GNUC_PREREQ (4, 5) : __GNUC_PREREQ (4, 4)))
  # define __HAVE_FLOAT128 1
  #else
  # define __HAVE_FLOAT128 0
--- 28,35 ----
     support, for x86_64 and x86. */
  #if (defined __x86_64__ \
       ? __GNUC_PREREQ (4, 3) \
! : (defined __GNU__ ? __GNUC_PREREQ (4, 5) : __GNUC_PREREQ (4, 4))) \
! && !defined(__CUDACC__)
  # define __HAVE_FLOAT128 1
  #else
  # define __HAVE_FLOAT128 0
-------------------------------------------------------------------------------------

(evidence)
----------
1. Here is part of message during compiing Tensorflow with CUDA on UBUNTU17.10 beta with proposed-components. .
--------------
typedef _Complex float __cfloat128 __attribute__ ((__mode__ (__TC__)));
                         ^
INFO: From Compiling external/nccl_archive/src/broadcast.cu.cc:
/usr/include/x86_64-linux-gnu/bits/floatn.h(61): error: invalid argument to attribute "__mode__"

/usr/include/x86_64-linux-gnu/bits/floatn.h(73): error: identifier "__float128" is undefined
--------------

2. Forums in Intel and NVIDIA
where issues the problems around glibc.2.26

NVIDIA
https://devtalk.nvidia.com/default/topic/1023776/cuda-programming-and-performance/-request-add-nvcc-compatibility-with-glibc-2-26/

3. THis bug has already discussed in Arch linux and the patch (tas same ) proposed
https://www.reddit.com/r/archlinux/comments/6zrmn1/torch_on_arch/