-march=native failing on Windows laptop

[Toon Moene]

On 11/28/2013 05:13 PM, Tim Prince wrote:

> Under gdb, it throws a segfault in the loop which is likely hanging
> outside of gdb.  There are avx2 instructions in that loop.

For comparison, I have *two* completely different weather forecasting 
systems running on my home computer:

processor	: 7
vendor_id	: GenuineIntel
cpu family	: 6
model		: 60
model name	: Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz
stepping	: 3
microcode	: 0x9
cpu MHz		: 800.000
cache size	: 8192 KB
physical id	: 0
siblings	: 8
core id		: 3
cpu cores	: 4
apicid		: 7
initial apicid	: 7
fpu		: yes
fpu_exception	: yes
cpuid level	: 13
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov 
pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx 
pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl 
xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor 
ds_cpl vmx smx est tm2 ssse3 fma cx16 xtpr pdcm pcid sse4_1 sse4_2 
x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm 
abm ida arat epb xsaveopt pln pts dtherm tpr_shadow vnmi flexpriority 
ept vpid fsgsbase tsc_adjust bmi1 hle avx2 smep bmi2 erms invpcid rtm
bogomips	: 6795.89
clflush size	: 64
cache_alignment	: 64
address sizes	: 39 bits physical, 48 bits virtual
power management:

for which gcc-4.8.2:

$ gfortran -v
Using built-in specs.
COLLECT_GCC=gfortran
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.8/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 4.8.2-1' 
--with-bugurl=file:///usr/share/doc/gcc-4.8/README.Bugs 
--enable-languages=c,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr 
--program-suffix=-4.8 --enable-shared --enable-linker-build-id 
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix 
--with-gxx-include-dir=/usr/include/c++/4.8 --libdir=/usr/lib 
--enable-nls --with-sysroot=/ --enable-clocale=gnu 
--enable-libstdcxx-debug --enable-libstdcxx-time=yes 
--enable-gnu-unique-object --enable-plugin --with-system-zlib 
--disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo 
--with-java-home=/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64/jre 
--enable-java-home 
--with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64 
--with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-4.8-amd64 
--with-arch-directory=amd64 
--with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-objc-gc 
--enable-multiarch --with-arch-32=i586 --with-abi=m64 
--with-multilib-list=m32,m64,mx32 --with-tune=generic 
--enable-checking=release --build=x86_64-linux-gnu 
--host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.8.2 (Debian 4.8.2-1)

generates *tons* of AVX2 instructions (including the new "gather" 
instruction), which work just fine.

So it might not be the AVX2 instructions *per se* that are your problem :-)

If the example code is short, we could try to turn it into a Bugzillable 
report ...

Kind regards,

-- 
Toon Moene - e-mail: toon@moene.org - phone: +31 346 214290
Saturnushof 14, 3738 XG  Maartensdijk, The Netherlands
At home: http://moene.org/~toon/; weather: http://moene.org/~hirlam/
Progress of GNU Fortran: http://gcc.gnu.org/wiki/GFortran#news