[Bug c++/54741] New: GCC 4.4, 4.5, 4.6 4.7 (probably 4.8) Generates un-usable code on AVX supported CPUs (FreeBSD)

["ace.of.zerosync at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54741

             Bug #: 54741
           Summary: GCC 4.4, 4.5, 4.6 4.7 (probably 4.8) Generates
                    un-usable code on AVX supported CPUs (FreeBSD)
    Classification: Unclassified
           Product: gcc
           Version: 4.6.4
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: ace.of.zerosync@gmail.com


Created attachment 28297
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=28297
both test.ii and test.s files from save-temp output

It's been quite a while that this bug is around with GCC 4.4+ on FreeBSD
systems (at least 8.2-Release and 9.0-Release which tested by me). If you have
a sandy-bridge or ivy-bridge cpu a code like this get killed by SIGILL when
compiled using -march=native:

#include <iostream>
#include <string>
#include <unordered_map>

int main() {
    std::unordered_map<std::string, std::string> hash; 
    std::cout << "Hello, World!" << std::endl;
    return 0;
}

# g++46 -std=c++0x -o test test.cpp
# ./test 
Hello, World!

# g++46 -std=c++0x -march=native -o test test.cpp
# ./test
Illegal instruction: 4

This is gdbs output:
Program received signal SIGILL, Illegal instruction.
0x00000000004011dc in std::_Hashtable<std::string, std::pair<std::string const,
std::string>, std::allocator<std::pair<std::string const, std::string> >,
std::_Select1st<std::pair<std::string const, std::string> >,
std::equal_to<std::string>, std::hash<std::string>,
std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash,
std::__detail::_Prime_rehash_policy, false, false, true>::_Hashtable ()

I know the code above is using C++11 standard headers, but this bug is not a
C++11 related bug, the code above is just a known example to me. If you look at
this thread (which was opened by me nearly 1.5 years ago) on FreeBSD forums
http://forums.freebsd.org/showthread.php?t=23535 you'll see even C code (GCC
itself and nearly anything compiled by -march=native on my system) affected by
this bug.


# g++46 -v -save-temps -std=c++0x -march=native -o test test.cpp
Using built-in specs.
COLLECT_GCC=g++46
COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc46/gcc/x86_64-portbld-freebsd9.0/4.6.4/lto-wrapper
Target: x86_64-portbld-freebsd9.0
Configured with: ./../gcc-4.6-20120831/configure --disable-nls
--enable-languages=c,c++,objc,fortran --libdir=/usr/local/lib/gcc46
--libexecdir=/usr/local/libexec/gcc46 --program-suffix=46
--with-as=/usr/local/bin/as --with-gmp=/usr/local
--with-gxx-include-dir=/usr/local/lib/gcc46/include/c++/
--with-ld=/usr/local/bin/ld --with-libiconv-prefix=/usr/local
--with-pkgversion='FreeBSD Ports Collection' --with-system-zlib
--disable-libgcj --prefix=/usr/local --mandir=/usr/local/man
--infodir=/usr/local/info/gcc46 --build=x86_64-portbld-freebsd9.0
Thread model: posix
gcc version 4.6.4 20120831 (prerelease) (FreeBSD Ports Collection) 
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-std=c++0x' '-march=native' '-o' 'test'
'-shared-libgcc'
 /usr/local/libexec/gcc46/gcc/x86_64-portbld-freebsd9.0/4.6.4/cc1plus -E -quiet
-v test.cpp -march=corei7-avx -mcx16 -msahf -mno-movbe -maes -mpclmul -mpopcnt
-mno-abm -mno-lwp -mno-fma -mno-fma4 -mno-xop -mno-bmi -mno-tbm -mavx -msse4.2
-msse4.1 -mno-rdrnd -mno-f16c -mno-fsgsbase --param l1-cache-size=32 --param
l1-cache-line-size=64 --param l2-cache-size=6144 -mtune=corei7-avx -std=c++0x
-fpch-preprocess -o test.ii
ignoring nonexistent directory
"/usr/local/lib/gcc46/gcc/x86_64-portbld-freebsd9.0/4.6.4/../../../../../x86_64-portbld-freebsd9.0/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/lib/gcc46/include/c++/
 /usr/local/lib/gcc46/include/c++//x86_64-portbld-freebsd9.0
 /usr/local/lib/gcc46/include/c++//backward
 /usr/local/lib/gcc46/gcc/x86_64-portbld-freebsd9.0/4.6.4/include
 /usr/local/include
 /usr/local/lib/gcc46/gcc/x86_64-portbld-freebsd9.0/4.6.4/include-fixed
 /usr/include
End of search list.
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-std=c++0x' '-march=native' '-o' 'test'
'-shared-libgcc'
 /usr/local/libexec/gcc46/gcc/x86_64-portbld-freebsd9.0/4.6.4/cc1plus
-fpreprocessed test.ii -march=corei7-avx -mcx16 -msahf -mno-movbe -maes
-mpclmul -mpopcnt -mno-abm -mno-lwp -mno-fma -mno-fma4 -mno-xop -mno-bmi
-mno-tbm -mavx -msse4.2 -msse4.1 -mno-rdrnd -mno-f16c -mno-fsgsbase --param
l1-cache-size=32 --param l1-cache-line-size=64 --param l2-cache-size=6144
-mtune=corei7-avx -quiet -dumpbase test.cpp -auxbase test -std=c++0x -version
-o test.s
GNU C++ (FreeBSD Ports Collection) version 4.6.4 20120831 (prerelease)
(x86_64-portbld-freebsd9.0)
    compiled by GNU C version 4.6.4 20120831 (prerelease), GMP version 5.0.5,
MPFR version 3.1.1, MPC version 0.9
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
GNU C++ (FreeBSD Ports Collection) version 4.6.4 20120831 (prerelease)
(x86_64-portbld-freebsd9.0)
    compiled by GNU C version 4.6.4 20120831 (prerelease), GMP version 5.0.5,
MPFR version 3.1.1, MPC version 0.9
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: f66add45a86dc64383d28918a222f366
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-std=c++0x' '-march=native' '-o' 'test'
'-shared-libgcc'
 /usr/local/bin/as -v -o test.o test.s
GNU assembler version 2.22 (x86_64-portbld-freebsd9.0) using BFD version (GNU
Binutils) 2.22
COMPILER_PATH=/usr/local/libexec/gcc46/gcc/x86_64-portbld-freebsd9.0/4.6.4/:/usr/local/libexec/gcc46/gcc/x86_64-portbld-freebsd9.0/4.6.4/:/usr/local/libexec/gcc46/gcc/x86_64-portbld-freebsd9.0/:/usr/local/lib/gcc46/gcc/x86_64-portbld-freebsd9.0/4.6.4/:/usr/local/lib/gcc46/gcc/x86_64-portbld-freebsd9.0/:/usr/local/lib/gcc46/gcc/x86_64-portbld-freebsd9.0/4.6.4/../../../../../x86_64-portbld-freebsd9.0/bin/
LIBRARY_PATH=/usr/local/lib/gcc46/gcc/x86_64-portbld-freebsd9.0/4.6.4/:/usr/local/lib/gcc46/gcc/x86_64-portbld-freebsd9.0/4.6.4/../../../../../x86_64-portbld-freebsd9.0/lib/:/usr/local/lib/gcc46/gcc/x86_64-portbld-freebsd9.0/4.6.4/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-std=c++0x' '-march=native' '-o' 'test'
'-shared-libgcc'
 /usr/local/libexec/gcc46/gcc/x86_64-portbld-freebsd9.0/4.6.4/collect2
--eh-frame-hdr -V -dynamic-linker /libexec/ld-elf.so.1 -o test /usr/lib/crt1.o
/usr/lib/crti.o
/usr/local/lib/gcc46/gcc/x86_64-portbld-freebsd9.0/4.6.4/crtbegin.o
-L/usr/local/lib/gcc46/gcc/x86_64-portbld-freebsd9.0/4.6.4
-L/usr/local/lib/gcc46/gcc/x86_64-portbld-freebsd9.0/4.6.4/../../../../../x86_64-portbld-freebsd9.0/lib
-L/usr/local/lib/gcc46/gcc/x86_64-portbld-freebsd9.0/4.6.4/../../.. test.o
-lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc
/usr/local/lib/gcc46/gcc/x86_64-portbld-freebsd9.0/4.6.4/crtend.o
/usr/lib/crtn.o
GNU ld (GNU Binutils) 2.22
  Supported emulations:
   elf_x86_64_fbsd
   elf_i386_fbsd
   elf_x86_64
   elf_i386
   elf_l1om
   elf_l1om_fbsd
   elf_k1om
   elf_k1om_fbsd