Bug#804561: GCC can't compile a program using RDSEED intrinsics

[Jeffrey Walton <noloader@gmail.com>]

Package: g++
Version: 4:5.2.1-4
Severity: normal
Control: tags jessie sid
Tags: jessie sid

**********

Another Debian specific bug... GCC can't compile a program using
RDSEED intrinsics. It results in an error "error: ‘_rdseed64_step’ was
not declared in this scope".

According the Intel (which the GCC told me to follow), RDSEED
intrinsics are available in <immintrin.h>. Confer,
http://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=rdseed.

The same program, using RDRAND, compiles fine.

**********

$ cat rdseed.cxx
#include <iostream>
#include <immintrin.h>

int main()
{
  unsigned long long val = 0;
  _rdseed64_step(&val);
  _rdseed32_step(&val);
  _rdseed16_step(&val);

  std::cout << val << std::endl;

  return !val;
}

$ g++ -mrdseed rdseed.cxx -o rdseed.exe
rdseed.cxx: In function ‘int main()’:
rdseed.cxx:7:22: error: ‘_rdseed64_step’ was not declared in this scope
   _rdseed64_step(&val);
                      ^
rdseed.cxx:8:22: error: ‘_rdseed32_step’ was not declared in this scope
   _rdseed32_step(&val);
                      ^
rdseed.cxx:9:22: error: ‘_rdseed16_step’ was not declared in this scope
   _rdseed16_step(&val);
                      ^

**********

$ g++ --version
g++ (Debian 5.2.1-20) 5.2.1 20151002

$ uname -a
Linux debian-8-x64 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt11-1+deb8u5
(2015-10-09) x86_64 GNU/Linux


**********

$ apt-cache show g++
Package: g++
Status: install ok installed
Priority: optional
Section: devel
Installed-Size: 17
Maintainer: Debian GCC Maintainers <debian-gcc@lists.debian.org>
Architecture: amd64
Source: gcc-defaults (1.145)
Version: 4:5.2.1-4
Provides: c++-compiler
Depends: cpp (>= 4:5.2.1-4), gcc (>= 4:5.2.1-4), g++-5 (>= 5.2.1-13~),
gcc-5 (>= 5.2.1-13~)
Suggests: g++-multilib
Description-en: GNU C++ compiler
 This is the GNU C++ compiler, a fairly portable optimizing compiler for C++.
 .
 This is a dependency package providing the default GNU C++ compiler.
Description-md5: 4d44b18774ae5123b7c3f70d940cf655

Package: g++
Source: gcc-defaults (1.136)
Version: 4:4.9.2-2
Installed-Size: 34
Maintainer: Debian GCC Maintainers <debian-gcc@lists.debian.org>
Architecture: amd64
Provides: c++-compiler
Depends: cpp (>= 4:4.9.2-2), gcc (>= 4:4.9.2-2), g++-4.9 (>=
4.6.4-1~), gcc-4.9 (>= 4.6.4-1~)
Suggests: g++-multilib
Description-en: GNU C++ compiler
 This is the GNU C++ compiler, a fairly portable optimizing compiler for C++.
 .
 This is a dependency package providing the default GNU C++ compiler.
Description-md5: 4d44b18774ae5123b7c3f70d940cf655
Build-Essential: yes
Tag: devel::compiler, devel::lang:c++, implemented-in::c,
 interface::commandline, role::dummy, role::metapackage, suite::gnu,
 works-with::software:source
Section: devel
Priority: optional
Filename: pool/main/g/gcc-defaults/g++_4.9.2-2_amd64.deb
Size: 1530
MD5sum: cd4aa68ba8cf582df806c324988e6a00
SHA1: 82a50c84e1105e1f0c767da82c09f2398ac2d4b2
SHA256: 6fb9842c6a0ad0cd5445b9f2f2cb3f738abcc83a6b8e0900aad441574f5cecee